import ethereum accounts package

copy from the following commit.

commit 9b831d74fbee3d59ceca380a40e4a9af1a55cfca
Author: Guillaume Ballet <gballet@gmail.com>
Date:   Tue May 7 18:22:24 2019 +0200

	accounts/usbwallet: fix a comment typo in trezor driver (#19535)

Signed-off-by: Leo Chen <leo@harmony.one>

accounts/abi/abi.go

@@ -0,0 +1,167 @@
+// Copyright 2015 The go-ethereum Authors
+// This file is part of the go-ethereum library.
+//
+// The go-ethereum library is free software: you can redistribute it and/or modify
+// it under the terms of the GNU Lesser General Public License as published by
+// the Free Software Foundation, either version 3 of the License, or
+// (at your option) any later version.
+//
+// The go-ethereum library is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+// GNU Lesser General Public License for more details.
+//
+// You should have received a copy of the GNU Lesser General Public License
+// along with the go-ethereum library. If not, see <http://www.gnu.org/licenses/>.
+
+package abi
+
+import (
+	"bytes"
+	"encoding/json"
+	"fmt"
+	"io"
+)
+
+// The ABI holds information about a contract's context and available
+// invokable methods. It will allow you to type check function calls and
+// packs data accordingly.
+type ABI struct {
+	Constructor Method
+	Methods     map[string]Method
+	Events      map[string]Event
+}
+
+// JSON returns a parsed ABI interface and error if it failed.
+func JSON(reader io.Reader) (ABI, error) {
+	dec := json.NewDecoder(reader)
+
+	var abi ABI
+	if err := dec.Decode(&abi); err != nil {
+		return ABI{}, err
+	}
+
+	return abi, nil
+}
+
+// Pack the given method name to conform the ABI. Method call's data
+// will consist of method_id, args0, arg1, ... argN. Method id consists
+// of 4 bytes and arguments are all 32 bytes.
+// Method ids are created from the first 4 bytes of the hash of the
+// methods string signature. (signature = baz(uint32,string32))
+func (abi ABI) Pack(name string, args ...interface{}) ([]byte, error) {
+	// Fetch the ABI of the requested method
+	if name == "" {
+		// constructor
+		arguments, err := abi.Constructor.Inputs.Pack(args...)
+		if err != nil {
+			return nil, err
+		}
+		return arguments, nil
+	}
+	method, exist := abi.Methods[name]
+	if !exist {
+		return nil, fmt.Errorf("method '%s' not found", name)
+	}
+	arguments, err := method.Inputs.Pack(args...)
+	if err != nil {
+		return nil, err
+	}
+	// Pack up the method ID too if not a constructor and return
+	return append(method.Id(), arguments...), nil
+}
+
+// Unpack output in v according to the abi specification
+func (abi ABI) Unpack(v interface{}, name string, data []byte) (err error) {
+	if len(data) == 0 {
+		return fmt.Errorf("abi: unmarshalling empty output")
+	}
+	// since there can't be naming collisions with contracts and events,
+	// we need to decide whether we're calling a method or an event
+	if method, ok := abi.Methods[name]; ok {
+		if len(data)%32 != 0 {
+			return fmt.Errorf("abi: improperly formatted output: %s - Bytes: [%+v]", string(data), data)
+		}
+		return method.Outputs.Unpack(v, data)
+	}
+	if event, ok := abi.Events[name]; ok {
+		return event.Inputs.Unpack(v, data)
+	}
+	return fmt.Errorf("abi: could not locate named method or event")
+}
+
+// UnpackIntoMap unpacks a log into the provided map[string]interface{}
+func (abi ABI) UnpackIntoMap(v map[string]interface{}, name string, data []byte) (err error) {
+	if len(data) == 0 {
+		return fmt.Errorf("abi: unmarshalling empty output")
+	}
+	// since there can't be naming collisions with contracts and events,
+	// we need to decide whether we're calling a method or an event
+	if method, ok := abi.Methods[name]; ok {
+		if len(data)%32 != 0 {
+			return fmt.Errorf("abi: improperly formatted output")
+		}
+		return method.Outputs.UnpackIntoMap(v, data)
+	}
+	if event, ok := abi.Events[name]; ok {
+		return event.Inputs.UnpackIntoMap(v, data)
+	}
+	return fmt.Errorf("abi: could not locate named method or event")
+}
+
+// UnmarshalJSON implements json.Unmarshaler interface
+func (abi *ABI) UnmarshalJSON(data []byte) error {
+	var fields []struct {
+		Type      string
+		Name      string
+		Constant  bool
+		Anonymous bool
+		Inputs    []Argument
+		Outputs   []Argument
+	}
+
+	if err := json.Unmarshal(data, &fields); err != nil {
+		return err
+	}
+
+	abi.Methods = make(map[string]Method)
+	abi.Events = make(map[string]Event)
+	for _, field := range fields {
+		switch field.Type {
+		case "constructor":
+			abi.Constructor = Method{
+				Inputs: field.Inputs,
+			}
+		// empty defaults to function according to the abi spec
+		case "function", "":
+			abi.Methods[field.Name] = Method{
+				Name:    field.Name,
+				Const:   field.Constant,
+				Inputs:  field.Inputs,
+				Outputs: field.Outputs,
+			}
+		case "event":
+			abi.Events[field.Name] = Event{
+				Name:      field.Name,
+				Anonymous: field.Anonymous,
+				Inputs:    field.Inputs,
+			}
+		}
+	}
+
+	return nil
+}
+
+// MethodById looks up a method by the 4-byte id
+// returns nil if none found
+func (abi *ABI) MethodById(sigdata []byte) (*Method, error) {
+	if len(sigdata) < 4 {
+		return nil, fmt.Errorf("data too short (%d bytes) for abi method lookup", len(sigdata))
+	}
+	for _, method := range abi.Methods {
+		if bytes.Equal(method.Id(), sigdata[:4]) {
+			return &method, nil
+		}
+	}
+	return nil, fmt.Errorf("no method with id: %#x", sigdata[:4])
+}

accounts/abi/abi_test.go

@@ -0,0 +1,933 @@
+// Copyright 2015 The go-ethereum Authors
+// This file is part of the go-ethereum library.
+//
+// The go-ethereum library is free software: you can redistribute it and/or modify
+// it under the terms of the GNU Lesser General Public License as published by
+// the Free Software Foundation, either version 3 of the License, or
+// (at your option) any later version.
+//
+// The go-ethereum library is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+// GNU Lesser General Public License for more details.
+//
+// You should have received a copy of the GNU Lesser General Public License
+// along with the go-ethereum library. If not, see <http://www.gnu.org/licenses/>.
+
+package abi
+
+import (
+	"bytes"
+	"encoding/hex"
+	"fmt"
+	"log"
+	"math/big"
+	"reflect"
+	"strings"
+	"testing"
+
+	"github.com/ethereum/go-ethereum/common"
+	"github.com/ethereum/go-ethereum/crypto"
+)
+
+const jsondata = `
+[
+	{ "type" : "function", "name" : "balance", "constant" : true },
+	{ "type" : "function", "name" : "send", "constant" : false, "inputs" : [ { "name" : "amount", "type" : "uint256" } ] }
+]`
+
+const jsondata2 = `
+[
+	{ "type" : "function", "name" : "balance", "constant" : true },
+	{ "type" : "function", "name" : "send", "constant" : false, "inputs" : [ { "name" : "amount", "type" : "uint256" } ] },
+	{ "type" : "function", "name" : "test", "constant" : false, "inputs" : [ { "name" : "number", "type" : "uint32" } ] },
+	{ "type" : "function", "name" : "string", "constant" : false, "inputs" : [ { "name" : "inputs", "type" : "string" } ] },
+	{ "type" : "function", "name" : "bool", "constant" : false, "inputs" : [ { "name" : "inputs", "type" : "bool" } ] },
+	{ "type" : "function", "name" : "address", "constant" : false, "inputs" : [ { "name" : "inputs", "type" : "address" } ] },
+	{ "type" : "function", "name" : "uint64[2]", "constant" : false, "inputs" : [ { "name" : "inputs", "type" : "uint64[2]" } ] },
+	{ "type" : "function", "name" : "uint64[]", "constant" : false, "inputs" : [ { "name" : "inputs", "type" : "uint64[]" } ] },
+	{ "type" : "function", "name" : "foo", "constant" : false, "inputs" : [ { "name" : "inputs", "type" : "uint32" } ] },
+	{ "type" : "function", "name" : "bar", "constant" : false, "inputs" : [ { "name" : "inputs", "type" : "uint32" }, { "name" : "string", "type" : "uint16" } ] },
+	{ "type" : "function", "name" : "slice", "constant" : false, "inputs" : [ { "name" : "inputs", "type" : "uint32[2]" } ] },
+	{ "type" : "function", "name" : "slice256", "constant" : false, "inputs" : [ { "name" : "inputs", "type" : "uint256[2]" } ] },
+	{ "type" : "function", "name" : "sliceAddress", "constant" : false, "inputs" : [ { "name" : "inputs", "type" : "address[]" } ] },
+	{ "type" : "function", "name" : "sliceMultiAddress", "constant" : false, "inputs" : [ { "name" : "a", "type" : "address[]" }, { "name" : "b", "type" : "address[]" } ] },
+	{ "type" : "function", "name" : "nestedArray", "constant" : false, "inputs" : [ { "name" : "a", "type" : "uint256[2][2]" }, { "name" : "b", "type" : "address[]" } ] },
+	{ "type" : "function", "name" : "nestedArray2", "constant" : false, "inputs" : [ { "name" : "a", "type" : "uint8[][2]" } ] },
+	{ "type" : "function", "name" : "nestedSlice", "constant" : false, "inputs" : [ { "name" : "a", "type" : "uint8[][]" } ] }
+]`
+
+func TestReader(t *testing.T) {
+	Uint256, _ := NewType("uint256", nil)
+	exp := ABI{
+		Methods: map[string]Method{
+			"balance": {
+				"balance", true, nil, nil,
+			},
+			"send": {
+				"send", false, []Argument{
+					{"amount", Uint256, false},
+				}, nil,
+			},
+		},
+	}
+
+	abi, err := JSON(strings.NewReader(jsondata))
+	if err != nil {
+		t.Error(err)
+	}
+
+	// deep equal fails for some reason
+	for name, expM := range exp.Methods {
+		gotM, exist := abi.Methods[name]
+		if !exist {
+			t.Errorf("Missing expected method %v", name)
+		}
+		if !reflect.DeepEqual(gotM, expM) {
+			t.Errorf("\nGot abi method: \n%v\ndoes not match expected method\n%v", gotM, expM)
+		}
+	}
+
+	for name, gotM := range abi.Methods {
+		expM, exist := exp.Methods[name]
+		if !exist {
+			t.Errorf("Found extra method %v", name)
+		}
+		if !reflect.DeepEqual(gotM, expM) {
+			t.Errorf("\nGot abi method: \n%v\ndoes not match expected method\n%v", gotM, expM)
+		}
+	}
+}
+
+func TestTestNumbers(t *testing.T) {
+	abi, err := JSON(strings.NewReader(jsondata2))
+	if err != nil {
+		t.Error(err)
+		t.FailNow()
+	}
+
+	if _, err := abi.Pack("balance"); err != nil {
+		t.Error(err)
+	}
+
+	if _, err := abi.Pack("balance", 1); err == nil {
+		t.Error("expected error for balance(1)")
+	}
+
+	if _, err := abi.Pack("doesntexist", nil); err == nil {
+		t.Errorf("doesntexist shouldn't exist")
+	}
+
+	if _, err := abi.Pack("doesntexist", 1); err == nil {
+		t.Errorf("doesntexist(1) shouldn't exist")
+	}
+
+	if _, err := abi.Pack("send", big.NewInt(1000)); err != nil {
+		t.Error(err)
+	}
+
+	i := new(int)
+	*i = 1000
+	if _, err := abi.Pack("send", i); err == nil {
+		t.Errorf("expected send( ptr ) to throw, requires *big.Int instead of *int")
+	}
+
+	if _, err := abi.Pack("test", uint32(1000)); err != nil {
+		t.Error(err)
+	}
+}
+
+func TestTestString(t *testing.T) {
+	abi, err := JSON(strings.NewReader(jsondata2))
+	if err != nil {
+		t.Error(err)
+		t.FailNow()
+	}
+
+	if _, err := abi.Pack("string", "hello world"); err != nil {
+		t.Error(err)
+	}
+}
+
+func TestTestBool(t *testing.T) {
+	abi, err := JSON(strings.NewReader(jsondata2))
+	if err != nil {
+		t.Error(err)
+		t.FailNow()
+	}
+
+	if _, err := abi.Pack("bool", true); err != nil {
+		t.Error(err)
+	}
+}
+
+func TestTestSlice(t *testing.T) {
+	abi, err := JSON(strings.NewReader(jsondata2))
+	if err != nil {
+		t.Error(err)
+		t.FailNow()
+	}
+
+	slice := make([]uint64, 2)
+	if _, err := abi.Pack("uint64[2]", slice); err != nil {
+		t.Error(err)
+	}
+
+	if _, err := abi.Pack("uint64[]", slice); err != nil {
+		t.Error(err)
+	}
+}
+
+func TestMethodSignature(t *testing.T) {
+	String, _ := NewType("string", nil)
+	m := Method{"foo", false, []Argument{{"bar", String, false}, {"baz", String, false}}, nil}
+	exp := "foo(string,string)"
+	if m.Sig() != exp {
+		t.Error("signature mismatch", exp, "!=", m.Sig())
+	}
+
+	idexp := crypto.Keccak256([]byte(exp))[:4]
+	if !bytes.Equal(m.Id(), idexp) {
+		t.Errorf("expected ids to match %x != %x", m.Id(), idexp)
+	}
+
+	uintt, _ := NewType("uint256", nil)
+	m = Method{"foo", false, []Argument{{"bar", uintt, false}}, nil}
+	exp = "foo(uint256)"
+	if m.Sig() != exp {
+		t.Error("signature mismatch", exp, "!=", m.Sig())
+	}
+
+	// Method with tuple arguments
+	s, _ := NewType("tuple", []ArgumentMarshaling{
+		{Name: "a", Type: "int256"},
+		{Name: "b", Type: "int256[]"},
+		{Name: "c", Type: "tuple[]", Components: []ArgumentMarshaling{
+			{Name: "x", Type: "int256"},
+			{Name: "y", Type: "int256"},
+		}},
+		{Name: "d", Type: "tuple[2]", Components: []ArgumentMarshaling{
+			{Name: "x", Type: "int256"},
+			{Name: "y", Type: "int256"},
+		}},
+	})
+	m = Method{"foo", false, []Argument{{"s", s, false}, {"bar", String, false}}, nil}
+	exp = "foo((int256,int256[],(int256,int256)[],(int256,int256)[2]),string)"
+	if m.Sig() != exp {
+		t.Error("signature mismatch", exp, "!=", m.Sig())
+	}
+}
+
+func TestMultiPack(t *testing.T) {
+	abi, err := JSON(strings.NewReader(jsondata2))
+	if err != nil {
+		t.Error(err)
+		t.FailNow()
+	}
+
+	sig := crypto.Keccak256([]byte("bar(uint32,uint16)"))[:4]
+	sig = append(sig, make([]byte, 64)...)
+	sig[35] = 10
+	sig[67] = 11
+
+	packed, err := abi.Pack("bar", uint32(10), uint16(11))
+	if err != nil {
+		t.Error(err)
+		t.FailNow()
+	}
+
+	if !bytes.Equal(packed, sig) {
+		t.Errorf("expected %x got %x", sig, packed)
+	}
+}
+
+func ExampleJSON() {
+	const definition = `[{"constant":true,"inputs":[{"name":"","type":"address"}],"name":"isBar","outputs":[{"name":"","type":"bool"}],"type":"function"}]`
+
+	abi, err := JSON(strings.NewReader(definition))
+	if err != nil {
+		log.Fatalln(err)
+	}
+	out, err := abi.Pack("isBar", common.HexToAddress("01"))
+	if err != nil {
+		log.Fatalln(err)
+	}
+
+	fmt.Printf("%x\n", out)
+	// Output:
+	// 1f2c40920000000000000000000000000000000000000000000000000000000000000001
+}
+
+func TestInputVariableInputLength(t *testing.T) {
+	const definition = `[
+	{ "type" : "function", "name" : "strOne", "constant" : true, "inputs" : [ { "name" : "str", "type" : "string" } ] },
+	{ "type" : "function", "name" : "bytesOne", "constant" : true, "inputs" : [ { "name" : "str", "type" : "bytes" } ] },
+	{ "type" : "function", "name" : "strTwo", "constant" : true, "inputs" : [ { "name" : "str", "type" : "string" }, { "name" : "str1", "type" : "string" } ] }
+	]`
+
+	abi, err := JSON(strings.NewReader(definition))
+	if err != nil {
+		t.Fatal(err)
+	}
+
+	// test one string
+	strin := "hello world"
+	strpack, err := abi.Pack("strOne", strin)
+	if err != nil {
+		t.Error(err)
+	}
+
+	offset := make([]byte, 32)
+	offset[31] = 32
+	length := make([]byte, 32)
+	length[31] = byte(len(strin))
+	value := common.RightPadBytes([]byte(strin), 32)
+	exp := append(offset, append(length, value...)...)
+
+	// ignore first 4 bytes of the output. This is the function identifier
+	strpack = strpack[4:]
+	if !bytes.Equal(strpack, exp) {
+		t.Errorf("expected %x, got %x\n", exp, strpack)
+	}
+
+	// test one bytes
+	btspack, err := abi.Pack("bytesOne", []byte(strin))
+	if err != nil {
+		t.Error(err)
+	}
+	// ignore first 4 bytes of the output. This is the function identifier
+	btspack = btspack[4:]
+	if !bytes.Equal(btspack, exp) {
+		t.Errorf("expected %x, got %x\n", exp, btspack)
+	}
+
+	//  test two strings
+	str1 := "hello"
+	str2 := "world"
+	str2pack, err := abi.Pack("strTwo", str1, str2)
+	if err != nil {
+		t.Error(err)
+	}
+
+	offset1 := make([]byte, 32)
+	offset1[31] = 64
+	length1 := make([]byte, 32)
+	length1[31] = byte(len(str1))
+	value1 := common.RightPadBytes([]byte(str1), 32)
+
+	offset2 := make([]byte, 32)
+	offset2[31] = 128
+	length2 := make([]byte, 32)
+	length2[31] = byte(len(str2))
+	value2 := common.RightPadBytes([]byte(str2), 32)
+
+	exp2 := append(offset1, offset2...)
+	exp2 = append(exp2, append(length1, value1...)...)
+	exp2 = append(exp2, append(length2, value2...)...)
+
+	// ignore first 4 bytes of the output. This is the function identifier
+	str2pack = str2pack[4:]
+	if !bytes.Equal(str2pack, exp2) {
+		t.Errorf("expected %x, got %x\n", exp, str2pack)
+	}
+
+	// test two strings, first > 32, second < 32
+	str1 = strings.Repeat("a", 33)
+	str2pack, err = abi.Pack("strTwo", str1, str2)
+	if err != nil {
+		t.Error(err)
+	}
+
+	offset1 = make([]byte, 32)
+	offset1[31] = 64
+	length1 = make([]byte, 32)
+	length1[31] = byte(len(str1))
+	value1 = common.RightPadBytes([]byte(str1), 64)
+	offset2[31] = 160
+
+	exp2 = append(offset1, offset2...)
+	exp2 = append(exp2, append(length1, value1...)...)
+	exp2 = append(exp2, append(length2, value2...)...)
+
+	// ignore first 4 bytes of the output. This is the function identifier
+	str2pack = str2pack[4:]
+	if !bytes.Equal(str2pack, exp2) {
+		t.Errorf("expected %x, got %x\n", exp, str2pack)
+	}
+
+	// test two strings, first > 32, second >32
+	str1 = strings.Repeat("a", 33)
+	str2 = strings.Repeat("a", 33)
+	str2pack, err = abi.Pack("strTwo", str1, str2)
+	if err != nil {
+		t.Error(err)
+	}
+
+	offset1 = make([]byte, 32)
+	offset1[31] = 64
+	length1 = make([]byte, 32)
+	length1[31] = byte(len(str1))
+	value1 = common.RightPadBytes([]byte(str1), 64)
+
+	offset2 = make([]byte, 32)
+	offset2[31] = 160
+	length2 = make([]byte, 32)
+	length2[31] = byte(len(str2))
+	value2 = common.RightPadBytes([]byte(str2), 64)
+
+	exp2 = append(offset1, offset2...)
+	exp2 = append(exp2, append(length1, value1...)...)
+	exp2 = append(exp2, append(length2, value2...)...)
+
+	// ignore first 4 bytes of the output. This is the function identifier
+	str2pack = str2pack[4:]
+	if !bytes.Equal(str2pack, exp2) {
+		t.Errorf("expected %x, got %x\n", exp, str2pack)
+	}
+}
+
+func TestInputFixedArrayAndVariableInputLength(t *testing.T) {
+	const definition = `[
+	{ "type" : "function", "name" : "fixedArrStr", "constant" : true, "inputs" : [ { "name" : "str", "type" : "string" }, { "name" : "fixedArr", "type" : "uint256[2]" } ] },
+	{ "type" : "function", "name" : "fixedArrBytes", "constant" : true, "inputs" : [ { "name" : "str", "type" : "bytes" }, { "name" : "fixedArr", "type" : "uint256[2]" } ] },
+    { "type" : "function", "name" : "mixedArrStr", "constant" : true, "inputs" : [ { "name" : "str", "type" : "string" }, { "name" : "fixedArr", "type": "uint256[2]" }, { "name" : "dynArr", "type": "uint256[]" } ] },
+    { "type" : "function", "name" : "doubleFixedArrStr", "constant" : true, "inputs" : [ { "name" : "str", "type" : "string" }, { "name" : "fixedArr1", "type": "uint256[2]" }, { "name" : "fixedArr2", "type": "uint256[3]" } ] },
+    { "type" : "function", "name" : "multipleMixedArrStr", "constant" : true, "inputs" : [ { "name" : "str", "type" : "string" }, { "name" : "fixedArr1", "type": "uint256[2]" }, { "name" : "dynArr", "type" : "uint256[]" }, { "name" : "fixedArr2", "type" : "uint256[3]" } ] }
+	]`
+
+	abi, err := JSON(strings.NewReader(definition))
+	if err != nil {
+		t.Error(err)
+	}
+
+	// test string, fixed array uint256[2]
+	strin := "hello world"
+	arrin := [2]*big.Int{big.NewInt(1), big.NewInt(2)}
+	fixedArrStrPack, err := abi.Pack("fixedArrStr", strin, arrin)
+	if err != nil {
+		t.Error(err)
+	}
+
+	// generate expected output
+	offset := make([]byte, 32)
+	offset[31] = 96
+	length := make([]byte, 32)
+	length[31] = byte(len(strin))
+	strvalue := common.RightPadBytes([]byte(strin), 32)
+	arrinvalue1 := common.LeftPadBytes(arrin[0].Bytes(), 32)
+	arrinvalue2 := common.LeftPadBytes(arrin[1].Bytes(), 32)
+	exp := append(offset, arrinvalue1...)
+	exp = append(exp, arrinvalue2...)
+	exp = append(exp, append(length, strvalue...)...)
+
+	// ignore first 4 bytes of the output. This is the function identifier
+	fixedArrStrPack = fixedArrStrPack[4:]
+	if !bytes.Equal(fixedArrStrPack, exp) {
+		t.Errorf("expected %x, got %x\n", exp, fixedArrStrPack)
+	}
+
+	// test byte array, fixed array uint256[2]
+	bytesin := []byte(strin)
+	arrin = [2]*big.Int{big.NewInt(1), big.NewInt(2)}
+	fixedArrBytesPack, err := abi.Pack("fixedArrBytes", bytesin, arrin)
+	if err != nil {
+		t.Error(err)
+	}
+
+	// generate expected output
+	offset = make([]byte, 32)
+	offset[31] = 96
+	length = make([]byte, 32)
+	length[31] = byte(len(strin))
+	strvalue = common.RightPadBytes([]byte(strin), 32)
+	arrinvalue1 = common.LeftPadBytes(arrin[0].Bytes(), 32)
+	arrinvalue2 = common.LeftPadBytes(arrin[1].Bytes(), 32)
+	exp = append(offset, arrinvalue1...)
+	exp = append(exp, arrinvalue2...)
+	exp = append(exp, append(length, strvalue...)...)
+
+	// ignore first 4 bytes of the output. This is the function identifier
+	fixedArrBytesPack = fixedArrBytesPack[4:]
+	if !bytes.Equal(fixedArrBytesPack, exp) {
+		t.Errorf("expected %x, got %x\n", exp, fixedArrBytesPack)
+	}
+
+	// test string, fixed array uint256[2], dynamic array uint256[]
+	strin = "hello world"
+	fixedarrin := [2]*big.Int{big.NewInt(1), big.NewInt(2)}
+	dynarrin := []*big.Int{big.NewInt(1), big.NewInt(2), big.NewInt(3)}
+	mixedArrStrPack, err := abi.Pack("mixedArrStr", strin, fixedarrin, dynarrin)
+	if err != nil {
+		t.Error(err)
+	}
+
+	// generate expected output
+	stroffset := make([]byte, 32)
+	stroffset[31] = 128
+	strlength := make([]byte, 32)
+	strlength[31] = byte(len(strin))
+	strvalue = common.RightPadBytes([]byte(strin), 32)
+	fixedarrinvalue1 := common.LeftPadBytes(fixedarrin[0].Bytes(), 32)
+	fixedarrinvalue2 := common.LeftPadBytes(fixedarrin[1].Bytes(), 32)
+	dynarroffset := make([]byte, 32)
+	dynarroffset[31] = byte(160 + ((len(strin)/32)+1)*32)
+	dynarrlength := make([]byte, 32)
+	dynarrlength[31] = byte(len(dynarrin))
+	dynarrinvalue1 := common.LeftPadBytes(dynarrin[0].Bytes(), 32)
+	dynarrinvalue2 := common.LeftPadBytes(dynarrin[1].Bytes(), 32)
+	dynarrinvalue3 := common.LeftPadBytes(dynarrin[2].Bytes(), 32)
+	exp = append(stroffset, fixedarrinvalue1...)
+	exp = append(exp, fixedarrinvalue2...)
+	exp = append(exp, dynarroffset...)
+	exp = append(exp, append(strlength, strvalue...)...)
+	dynarrarg := append(dynarrlength, dynarrinvalue1...)
+	dynarrarg = append(dynarrarg, dynarrinvalue2...)
+	dynarrarg = append(dynarrarg, dynarrinvalue3...)
+	exp = append(exp, dynarrarg...)
+
+	// ignore first 4 bytes of the output. This is the function identifier
+	mixedArrStrPack = mixedArrStrPack[4:]
+	if !bytes.Equal(mixedArrStrPack, exp) {
+		t.Errorf("expected %x, got %x\n", exp, mixedArrStrPack)
+	}
+
+	// test string, fixed array uint256[2], fixed array uint256[3]
+	strin = "hello world"
+	fixedarrin1 := [2]*big.Int{big.NewInt(1), big.NewInt(2)}
+	fixedarrin2 := [3]*big.Int{big.NewInt(1), big.NewInt(2), big.NewInt(3)}
+	doubleFixedArrStrPack, err := abi.Pack("doubleFixedArrStr", strin, fixedarrin1, fixedarrin2)
+	if err != nil {
+		t.Error(err)
+	}
+
+	// generate expected output
+	stroffset = make([]byte, 32)
+	stroffset[31] = 192
+	strlength = make([]byte, 32)
+	strlength[31] = byte(len(strin))
+	strvalue = common.RightPadBytes([]byte(strin), 32)
+	fixedarrin1value1 := common.LeftPadBytes(fixedarrin1[0].Bytes(), 32)
+	fixedarrin1value2 := common.LeftPadBytes(fixedarrin1[1].Bytes(), 32)
+	fixedarrin2value1 := common.LeftPadBytes(fixedarrin2[0].Bytes(), 32)
+	fixedarrin2value2 := common.LeftPadBytes(fixedarrin2[1].Bytes(), 32)
+	fixedarrin2value3 := common.LeftPadBytes(fixedarrin2[2].Bytes(), 32)
+	exp = append(stroffset, fixedarrin1value1...)
+	exp = append(exp, fixedarrin1value2...)
+	exp = append(exp, fixedarrin2value1...)
+	exp = append(exp, fixedarrin2value2...)
+	exp = append(exp, fixedarrin2value3...)
+	exp = append(exp, append(strlength, strvalue...)...)
+
+	// ignore first 4 bytes of the output. This is the function identifier
+	doubleFixedArrStrPack = doubleFixedArrStrPack[4:]
+	if !bytes.Equal(doubleFixedArrStrPack, exp) {
+		t.Errorf("expected %x, got %x\n", exp, doubleFixedArrStrPack)
+	}
+
+	// test string, fixed array uint256[2], dynamic array uint256[], fixed array uint256[3]
+	strin = "hello world"
+	fixedarrin1 = [2]*big.Int{big.NewInt(1), big.NewInt(2)}
+	dynarrin = []*big.Int{big.NewInt(1), big.NewInt(2)}
+	fixedarrin2 = [3]*big.Int{big.NewInt(1), big.NewInt(2), big.NewInt(3)}
+	multipleMixedArrStrPack, err := abi.Pack("multipleMixedArrStr", strin, fixedarrin1, dynarrin, fixedarrin2)
+	if err != nil {
+		t.Error(err)
+	}
+
+	// generate expected output
+	stroffset = make([]byte, 32)
+	stroffset[31] = 224
+	strlength = make([]byte, 32)
+	strlength[31] = byte(len(strin))
+	strvalue = common.RightPadBytes([]byte(strin), 32)
+	fixedarrin1value1 = common.LeftPadBytes(fixedarrin1[0].Bytes(), 32)
+	fixedarrin1value2 = common.LeftPadBytes(fixedarrin1[1].Bytes(), 32)
+	dynarroffset = U256(big.NewInt(int64(256 + ((len(strin)/32)+1)*32)))
+	dynarrlength = make([]byte, 32)
+	dynarrlength[31] = byte(len(dynarrin))
+	dynarrinvalue1 = common.LeftPadBytes(dynarrin[0].Bytes(), 32)
+	dynarrinvalue2 = common.LeftPadBytes(dynarrin[1].Bytes(), 32)
+	fixedarrin2value1 = common.LeftPadBytes(fixedarrin2[0].Bytes(), 32)
+	fixedarrin2value2 = common.LeftPadBytes(fixedarrin2[1].Bytes(), 32)
+	fixedarrin2value3 = common.LeftPadBytes(fixedarrin2[2].Bytes(), 32)
+	exp = append(stroffset, fixedarrin1value1...)
+	exp = append(exp, fixedarrin1value2...)
+	exp = append(exp, dynarroffset...)
+	exp = append(exp, fixedarrin2value1...)
+	exp = append(exp, fixedarrin2value2...)
+	exp = append(exp, fixedarrin2value3...)
+	exp = append(exp, append(strlength, strvalue...)...)
+	dynarrarg = append(dynarrlength, dynarrinvalue1...)
+	dynarrarg = append(dynarrarg, dynarrinvalue2...)
+	exp = append(exp, dynarrarg...)
+
+	// ignore first 4 bytes of the output. This is the function identifier
+	multipleMixedArrStrPack = multipleMixedArrStrPack[4:]
+	if !bytes.Equal(multipleMixedArrStrPack, exp) {
+		t.Errorf("expected %x, got %x\n", exp, multipleMixedArrStrPack)
+	}
+}
+
+func TestDefaultFunctionParsing(t *testing.T) {
+	const definition = `[{ "name" : "balance" }]`
+
+	abi, err := JSON(strings.NewReader(definition))
+	if err != nil {
+		t.Fatal(err)
+	}
+
+	if _, ok := abi.Methods["balance"]; !ok {
+		t.Error("expected 'balance' to be present")
+	}
+}
+
+func TestBareEvents(t *testing.T) {
+	const definition = `[
+	{ "type" : "event", "name" : "balance" },
+	{ "type" : "event", "name" : "anon", "anonymous" : true},
+	{ "type" : "event", "name" : "args", "inputs" : [{ "indexed":false, "name":"arg0", "type":"uint256" }, { "indexed":true, "name":"arg1", "type":"address" }] },
+	{ "type" : "event", "name" : "tuple", "inputs" : [{ "indexed":false, "name":"t", "type":"tuple", "components":[{"name":"a", "type":"uint256"}] }, { "indexed":true, "name":"arg1", "type":"address" }] }
+	]`
+
+	arg0, _ := NewType("uint256", nil)
+	arg1, _ := NewType("address", nil)
+	tuple, _ := NewType("tuple", []ArgumentMarshaling{{Name: "a", Type: "uint256"}})
+
+	expectedEvents := map[string]struct {
+		Anonymous bool
+		Args      []Argument
+	}{
+		"balance": {false, nil},
+		"anon":    {true, nil},
+		"args": {false, []Argument{
+			{Name: "arg0", Type: arg0, Indexed: false},
+			{Name: "arg1", Type: arg1, Indexed: true},
+		}},
+		"tuple": {false, []Argument{
+			{Name: "t", Type: tuple, Indexed: false},
+			{Name: "arg1", Type: arg1, Indexed: true},
+		}},
+	}
+
+	abi, err := JSON(strings.NewReader(definition))
+	if err != nil {
+		t.Fatal(err)
+	}
+
+	if len(abi.Events) != len(expectedEvents) {
+		t.Fatalf("invalid number of events after parsing, want %d, got %d", len(expectedEvents), len(abi.Events))
+	}
+
+	for name, exp := range expectedEvents {
+		got, ok := abi.Events[name]
+		if !ok {
+			t.Errorf("could not found event %s", name)
+			continue
+		}
+		if got.Anonymous != exp.Anonymous {
+			t.Errorf("invalid anonymous indication for event %s, want %v, got %v", name, exp.Anonymous, got.Anonymous)
+		}
+		if len(got.Inputs) != len(exp.Args) {
+			t.Errorf("invalid number of args, want %d, got %d", len(exp.Args), len(got.Inputs))
+			continue
+		}
+		for i, arg := range exp.Args {
+			if arg.Name != got.Inputs[i].Name {
+				t.Errorf("events[%s].Input[%d] has an invalid name, want %s, got %s", name, i, arg.Name, got.Inputs[i].Name)
+			}
+			if arg.Indexed != got.Inputs[i].Indexed {
+				t.Errorf("events[%s].Input[%d] has an invalid indexed indication, want %v, got %v", name, i, arg.Indexed, got.Inputs[i].Indexed)
+			}
+			if arg.Type.T != got.Inputs[i].Type.T {
+				t.Errorf("events[%s].Input[%d] has an invalid type, want %x, got %x", name, i, arg.Type.T, got.Inputs[i].Type.T)
+			}
+		}
+	}
+}
+
+// TestUnpackEvent is based on this contract:
+//    contract T {
+//      event received(address sender, uint amount, bytes memo);
+//      event receivedAddr(address sender);
+//      function receive(bytes memo) external payable {
+//        received(msg.sender, msg.value, memo);
+//        receivedAddr(msg.sender);
+//      }
+//    }
+// When receive("X") is called with sender 0x00... and value 1, it produces this tx receipt:
+//   receipt{status=1 cgas=23949 bloom=00000000004000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000800000000000000000000000000000000000040200000000000000000000000000000000001000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000080000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000 logs=[log: b6818c8064f645cd82d99b59a1a267d6d61117ef [75fd880d39c1daf53b6547ab6cb59451fc6452d27caa90e5b6649dd8293b9eed] 000000000000000000000000376c47978271565f56deb45495afa69e59c16ab200000000000000000000000000000000000000000000000000000000000000010000000000000000000000000000000000000000000000000000000000000060000000000000000000000000000000000000000000000000000000000000000158 9ae378b6d4409eada347a5dc0c180f186cb62dc68fcc0f043425eb917335aa28 0 95d429d309bb9d753954195fe2d69bd140b4ae731b9b5b605c34323de162cf00 0]}
+func TestUnpackEvent(t *testing.T) {
+	const abiJSON = `[{"constant":false,"inputs":[{"name":"memo","type":"bytes"}],"name":"receive","outputs":[],"payable":true,"stateMutability":"payable","type":"function"},{"anonymous":false,"inputs":[{"indexed":false,"name":"sender","type":"address"},{"indexed":false,"name":"amount","type":"uint256"},{"indexed":false,"name":"memo","type":"bytes"}],"name":"received","type":"event"},{"anonymous":false,"inputs":[{"indexed":false,"name":"sender","type":"address"}],"name":"receivedAddr","type":"event"}]`
+	abi, err := JSON(strings.NewReader(abiJSON))
+	if err != nil {
+		t.Fatal(err)
+	}
+
+	const hexdata = `000000000000000000000000376c47978271565f56deb45495afa69e59c16ab200000000000000000000000000000000000000000000000000000000000000010000000000000000000000000000000000000000000000000000000000000060000000000000000000000000000000000000000000000000000000000000000158`
+	data, err := hex.DecodeString(hexdata)
+	if err != nil {
+		t.Fatal(err)
+	}
+	if len(data)%32 == 0 {
+		t.Errorf("len(data) is %d, want a non-multiple of 32", len(data))
+	}
+
+	type ReceivedEvent struct {
+		Sender common.Address
+		Amount *big.Int
+		Memo   []byte
+	}
+	var ev ReceivedEvent
+
+	err = abi.Unpack(&ev, "received", data)
+	if err != nil {
+		t.Error(err)
+	}
+
+	type ReceivedAddrEvent struct {
+		Sender common.Address
+	}
+	var receivedAddrEv ReceivedAddrEvent
+	err = abi.Unpack(&receivedAddrEv, "receivedAddr", data)
+	if err != nil {
+		t.Error(err)
+	}
+}
+
+func TestUnpackEventIntoMap(t *testing.T) {
+	const abiJSON = `[{"constant":false,"inputs":[{"name":"memo","type":"bytes"}],"name":"receive","outputs":[],"payable":true,"stateMutability":"payable","type":"function"},{"anonymous":false,"inputs":[{"indexed":false,"name":"sender","type":"address"},{"indexed":false,"name":"amount","type":"uint256"},{"indexed":false,"name":"memo","type":"bytes"}],"name":"received","type":"event"},{"anonymous":false,"inputs":[{"indexed":false,"name":"sender","type":"address"}],"name":"receivedAddr","type":"event"}]`
+	abi, err := JSON(strings.NewReader(abiJSON))
+	if err != nil {
+		t.Fatal(err)
+	}
+
+	const hexdata = `000000000000000000000000376c47978271565f56deb45495afa69e59c16ab200000000000000000000000000000000000000000000000000000000000000010000000000000000000000000000000000000000000000000000000000000060000000000000000000000000000000000000000000000000000000000000000158`
+	data, err := hex.DecodeString(hexdata)
+	if err != nil {
+		t.Fatal(err)
+	}
+	if len(data)%32 == 0 {
+		t.Errorf("len(data) is %d, want a non-multiple of 32", len(data))
+	}
+
+	receivedMap := map[string]interface{}{}
+	expectedReceivedMap := map[string]interface{}{
+		"sender": common.HexToAddress("0x376c47978271565f56DEB45495afa69E59c16Ab2"),
+		"amount": big.NewInt(1),
+		"memo":   []byte{88},
+	}
+	if err := abi.UnpackIntoMap(receivedMap, "received", data); err != nil {
+		t.Error(err)
+	}
+	if len(receivedMap) != 3 {
+		t.Error("unpacked `received` map expected to have length 3")
+	}
+	if receivedMap["sender"] != expectedReceivedMap["sender"] {
+		t.Error("unpacked `received` map does not match expected map")
+	}
+	if receivedMap["amount"].(*big.Int).Cmp(expectedReceivedMap["amount"].(*big.Int)) != 0 {
+		t.Error("unpacked `received` map does not match expected map")
+	}
+	if !bytes.Equal(receivedMap["memo"].([]byte), expectedReceivedMap["memo"].([]byte)) {
+		t.Error("unpacked `received` map does not match expected map")
+	}
+
+	receivedAddrMap := map[string]interface{}{}
+	if err = abi.UnpackIntoMap(receivedAddrMap, "receivedAddr", data); err != nil {
+		t.Error(err)
+	}
+	if len(receivedAddrMap) != 1 {
+		t.Error("unpacked `receivedAddr` map expected to have length 1")
+	}
+	if receivedAddrMap["sender"] != expectedReceivedMap["sender"] {
+		t.Error("unpacked `receivedAddr` map does not match expected map")
+	}
+}
+
+func TestUnpackMethodIntoMap(t *testing.T) {
+	const abiJSON = `[{"constant":false,"inputs":[{"name":"memo","type":"bytes"}],"name":"receive","outputs":[],"payable":true,"stateMutability":"payable","type":"function"},{"constant":false,"inputs":[],"name":"send","outputs":[{"name":"amount","type":"uint256"}],"payable":true,"stateMutability":"payable","type":"function"},{"constant":false,"inputs":[{"name":"addr","type":"address"}],"name":"get","outputs":[{"name":"hash","type":"bytes"}],"payable":true,"stateMutability":"payable","type":"function"}]`
+	abi, err := JSON(strings.NewReader(abiJSON))
+	if err != nil {
+		t.Fatal(err)
+	}
+	const hexdata = `00000000000000000000000000000000000000000000000000000000000000010000000000000000000000000000000000000000000000000000000000000060000000000000000000000000000000000000000000000000000000000000015800000000000000000000000000000000000000000000000000000000000000600000000000000000000000000000000000000000000000000000000000000158000000000000000000000000000000000000000000000000000000000000006000000000000000000000000000000000000000000000000000000000000001580000000000000000000000000000000000000000000000000000000000000060000000000000000000000000000000000000000000000000000000000000015800000000000000000000000000000000000000000000000000000000000000600000000000000000000000000000000000000000000000000000000000000158`
+	data, err := hex.DecodeString(hexdata)
+	if err != nil {
+		t.Fatal(err)
+	}
+	if len(data)%32 != 0 {
+		t.Errorf("len(data) is %d, want a multiple of 32", len(data))
+	}
+
+	// Tests a method with no outputs
+	receiveMap := map[string]interface{}{}
+	if err = abi.UnpackIntoMap(receiveMap, "receive", data); err != nil {
+		t.Error(err)
+	}
+	if len(receiveMap) > 0 {
+		t.Error("unpacked `receive` map expected to have length 0")
+	}
+
+	// Tests a method with only outputs
+	sendMap := map[string]interface{}{}
+	if err = abi.UnpackIntoMap(sendMap, "send", data); err != nil {
+		t.Error(err)
+	}
+	if len(sendMap) != 1 {
+		t.Error("unpacked `send` map expected to have length 1")
+	}
+	if sendMap["amount"].(*big.Int).Cmp(big.NewInt(1)) != 0 {
+		t.Error("unpacked `send` map expected `amount` value of 1")
+	}
+
+	// Tests a method with outputs and inputs
+	getMap := map[string]interface{}{}
+	if err = abi.UnpackIntoMap(getMap, "get", data); err != nil {
+		t.Error(err)
+	}
+	if len(sendMap) != 1 {
+		t.Error("unpacked `get` map expected to have length 1")
+	}
+	expectedBytes := []byte{0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 96, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1, 88, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 96, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1, 88, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 96, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1, 88, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 96, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1, 88, 0}
+	if !bytes.Equal(getMap["hash"].([]byte), expectedBytes) {
+		t.Errorf("unpacked `get` map expected `hash` value of %v", expectedBytes)
+	}
+}
+
+func TestUnpackIntoMapNamingConflict(t *testing.T) {
+	// Two methods have the same name
+	var abiJSON = `[{"constant":false,"inputs":[{"name":"memo","type":"bytes"}],"name":"get","outputs":[],"payable":true,"stateMutability":"payable","type":"function"},{"constant":false,"inputs":[],"name":"send","outputs":[{"name":"amount","type":"uint256"}],"payable":true,"stateMutability":"payable","type":"function"},{"constant":false,"inputs":[{"name":"addr","type":"address"}],"name":"get","outputs":[{"name":"hash","type":"bytes"}],"payable":true,"stateMutability":"payable","type":"function"}]`
+	abi, err := JSON(strings.NewReader(abiJSON))
+	if err != nil {
+		t.Fatal(err)
+	}
+	var hexdata = `00000000000000000000000000000000000000000000000000000000000000010000000000000000000000000000000000000000000000000000000000000060000000000000000000000000000000000000000000000000000000000000000158`
+	data, err := hex.DecodeString(hexdata)
+	if err != nil {
+		t.Fatal(err)
+	}
+	if len(data)%32 == 0 {
+		t.Errorf("len(data) is %d, want a non-multiple of 32", len(data))
+	}
+	getMap := map[string]interface{}{}
+	if err = abi.UnpackIntoMap(getMap, "get", data); err == nil {
+		t.Error("naming conflict between two methods; error expected")
+	}
+
+	// Two events have the same name
+	abiJSON = `[{"constant":false,"inputs":[{"name":"memo","type":"bytes"}],"name":"receive","outputs":[],"payable":true,"stateMutability":"payable","type":"function"},{"anonymous":false,"inputs":[{"indexed":false,"name":"sender","type":"address"},{"indexed":false,"name":"amount","type":"uint256"},{"indexed":false,"name":"memo","type":"bytes"}],"name":"received","type":"event"},{"anonymous":false,"inputs":[{"indexed":false,"name":"sender","type":"address"}],"name":"received","type":"event"}]`
+	abi, err = JSON(strings.NewReader(abiJSON))
+	if err != nil {
+		t.Fatal(err)
+	}
+	hexdata = `000000000000000000000000376c47978271565f56deb45495afa69e59c16ab200000000000000000000000000000000000000000000000000000000000000010000000000000000000000000000000000000000000000000000000000000060000000000000000000000000000000000000000000000000000000000000000158`
+	data, err = hex.DecodeString(hexdata)
+	if err != nil {
+		t.Fatal(err)
+	}
+	if len(data)%32 == 0 {
+		t.Errorf("len(data) is %d, want a non-multiple of 32", len(data))
+	}
+	receivedMap := map[string]interface{}{}
+	if err = abi.UnpackIntoMap(receivedMap, "received", data); err != nil {
+		t.Error("naming conflict between two events; no error expected")
+	}
+	if len(receivedMap) != 1 {
+		t.Error("naming conflict between two events; event defined latest in the abi expected to be used")
+	}
+
+	// Method and event have the same name
+	abiJSON = `[{"constant":false,"inputs":[{"name":"memo","type":"bytes"}],"name":"received","outputs":[],"payable":true,"stateMutability":"payable","type":"function"},{"anonymous":false,"inputs":[{"indexed":false,"name":"sender","type":"address"},{"indexed":false,"name":"amount","type":"uint256"},{"indexed":false,"name":"memo","type":"bytes"}],"name":"received","type":"event"},{"anonymous":false,"inputs":[{"indexed":false,"name":"sender","type":"address"}],"name":"receivedAddr","type":"event"}]`
+	abi, err = JSON(strings.NewReader(abiJSON))
+	if err != nil {
+		t.Fatal(err)
+	}
+	if len(data)%32 == 0 {
+		t.Errorf("len(data) is %d, want a non-multiple of 32", len(data))
+	}
+	if err = abi.UnpackIntoMap(receivedMap, "received", data); err == nil {
+		t.Error("naming conflict between an event and a method; error expected")
+	}
+
+	// Conflict is case sensitive
+	abiJSON = `[{"constant":false,"inputs":[{"name":"memo","type":"bytes"}],"name":"received","outputs":[],"payable":true,"stateMutability":"payable","type":"function"},{"anonymous":false,"inputs":[{"indexed":false,"name":"sender","type":"address"},{"indexed":false,"name":"amount","type":"uint256"},{"indexed":false,"name":"memo","type":"bytes"}],"name":"Received","type":"event"},{"anonymous":false,"inputs":[{"indexed":false,"name":"sender","type":"address"}],"name":"receivedAddr","type":"event"}]`
+	abi, err = JSON(strings.NewReader(abiJSON))
+	if err != nil {
+		t.Fatal(err)
+	}
+	if len(data)%32 == 0 {
+		t.Errorf("len(data) is %d, want a non-multiple of 32", len(data))
+	}
+	expectedReceivedMap := map[string]interface{}{
+		"sender": common.HexToAddress("0x376c47978271565f56DEB45495afa69E59c16Ab2"),
+		"amount": big.NewInt(1),
+		"memo":   []byte{88},
+	}
+	if err = abi.UnpackIntoMap(receivedMap, "Received", data); err != nil {
+		t.Error(err)
+	}
+	if len(receivedMap) != 3 {
+		t.Error("unpacked `received` map expected to have length 3")
+	}
+	if receivedMap["sender"] != expectedReceivedMap["sender"] {
+		t.Error("unpacked `received` map does not match expected map")
+	}
+	if receivedMap["amount"].(*big.Int).Cmp(expectedReceivedMap["amount"].(*big.Int)) != 0 {
+		t.Error("unpacked `received` map does not match expected map")
+	}
+	if !bytes.Equal(receivedMap["memo"].([]byte), expectedReceivedMap["memo"].([]byte)) {
+		t.Error("unpacked `received` map does not match expected map")
+	}
+}
+
+func TestABI_MethodById(t *testing.T) {
+	const abiJSON = `[
+		{"type":"function","name":"receive","constant":false,"inputs":[{"name":"memo","type":"bytes"}],"outputs":[],"payable":true,"stateMutability":"payable"},
+		{"type":"event","name":"received","anonymous":false,"inputs":[{"indexed":false,"name":"sender","type":"address"},{"indexed":false,"name":"amount","type":"uint256"},{"indexed":false,"name":"memo","type":"bytes"}]},
+		{"type":"function","name":"fixedArrStr","constant":true,"inputs":[{"name":"str","type":"string"},{"name":"fixedArr","type":"uint256[2]"}]},
+		{"type":"function","name":"fixedArrBytes","constant":true,"inputs":[{"name":"str","type":"bytes"},{"name":"fixedArr","type":"uint256[2]"}]},
+		{"type":"function","name":"mixedArrStr","constant":true,"inputs":[{"name":"str","type":"string"},{"name":"fixedArr","type":"uint256[2]"},{"name":"dynArr","type":"uint256[]"}]},
+		{"type":"function","name":"doubleFixedArrStr","constant":true,"inputs":[{"name":"str","type":"string"},{"name":"fixedArr1","type":"uint256[2]"},{"name":"fixedArr2","type":"uint256[3]"}]},
+		{"type":"function","name":"multipleMixedArrStr","constant":true,"inputs":[{"name":"str","type":"string"},{"name":"fixedArr1","type":"uint256[2]"},{"name":"dynArr","type":"uint256[]"},{"name":"fixedArr2","type":"uint256[3]"}]},
+		{"type":"function","name":"balance","constant":true},
+		{"type":"function","name":"send","constant":false,"inputs":[{"name":"amount","type":"uint256"}]},
+		{"type":"function","name":"test","constant":false,"inputs":[{"name":"number","type":"uint32"}]},
+		{"type":"function","name":"string","constant":false,"inputs":[{"name":"inputs","type":"string"}]},
+		{"type":"function","name":"bool","constant":false,"inputs":[{"name":"inputs","type":"bool"}]},
+		{"type":"function","name":"address","constant":false,"inputs":[{"name":"inputs","type":"address"}]},
+		{"type":"function","name":"uint64[2]","constant":false,"inputs":[{"name":"inputs","type":"uint64[2]"}]},
+		{"type":"function","name":"uint64[]","constant":false,"inputs":[{"name":"inputs","type":"uint64[]"}]},
+		{"type":"function","name":"foo","constant":false,"inputs":[{"name":"inputs","type":"uint32"}]},
+		{"type":"function","name":"bar","constant":false,"inputs":[{"name":"inputs","type":"uint32"},{"name":"string","type":"uint16"}]},
+		{"type":"function","name":"_slice","constant":false,"inputs":[{"name":"inputs","type":"uint32[2]"}]},
+		{"type":"function","name":"__slice256","constant":false,"inputs":[{"name":"inputs","type":"uint256[2]"}]},
+		{"type":"function","name":"sliceAddress","constant":false,"inputs":[{"name":"inputs","type":"address[]"}]},
+		{"type":"function","name":"sliceMultiAddress","constant":false,"inputs":[{"name":"a","type":"address[]"},{"name":"b","type":"address[]"}]}
+	]
+`
+	abi, err := JSON(strings.NewReader(abiJSON))
+	if err != nil {
+		t.Fatal(err)
+	}
+	for name, m := range abi.Methods {
+		a := fmt.Sprintf("%v", m)
+		m2, err := abi.MethodById(m.Id())
+		if err != nil {
+			t.Fatalf("Failed to look up ABI method: %v", err)
+		}
+		b := fmt.Sprintf("%v", m2)
+		if a != b {
+			t.Errorf("Method %v (id %v) not 'findable' by id in ABI", name, common.ToHex(m.Id()))
+		}
+	}
+	// Also test empty
+	if _, err := abi.MethodById([]byte{0x00}); err == nil {
+		t.Errorf("Expected error, too short to decode data")
+	}
+	if _, err := abi.MethodById([]byte{}); err == nil {
+		t.Errorf("Expected error, too short to decode data")
+	}
+	if _, err := abi.MethodById(nil); err == nil {
+		t.Errorf("Expected error, nil is short to decode data")
+	}
+}

accounts/abi/argument.go

@@ -0,0 +1,354 @@
+// Copyright 2015 The go-ethereum Authors
+// This file is part of the go-ethereum library.
+//
+// The go-ethereum library is free software: you can redistribute it and/or modify
+// it under the terms of the GNU Lesser General Public License as published by
+// the Free Software Foundation, either version 3 of the License, or
+// (at your option) any later version.
+//
+// The go-ethereum library is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+// GNU Lesser General Public License for more details.
+//
+// You should have received a copy of the GNU Lesser General Public License
+// along with the go-ethereum library. If not, see <http://www.gnu.org/licenses/>.
+
+package abi
+
+import (
+	"encoding/json"
+	"fmt"
+	"reflect"
+	"strings"
+)
+
+// Argument holds the name of the argument and the corresponding type.
+// Types are used when packing and testing arguments.
+type Argument struct {
+	Name    string
+	Type    Type
+	Indexed bool // indexed is only used by events
+}
+
+type Arguments []Argument
+
+type ArgumentMarshaling struct {
+	Name       string
+	Type       string
+	Components []ArgumentMarshaling
+	Indexed    bool
+}
+
+// UnmarshalJSON implements json.Unmarshaler interface
+func (argument *Argument) UnmarshalJSON(data []byte) error {
+	var arg ArgumentMarshaling
+	err := json.Unmarshal(data, &arg)
+	if err != nil {
+		return fmt.Errorf("argument json err: %v", err)
+	}
+
+	argument.Type, err = NewType(arg.Type, arg.Components)
+	if err != nil {
+		return err
+	}
+	argument.Name = arg.Name
+	argument.Indexed = arg.Indexed
+
+	return nil
+}
+
+// LengthNonIndexed returns the number of arguments when not counting 'indexed' ones. Only events
+// can ever have 'indexed' arguments, it should always be false on arguments for method input/output
+func (arguments Arguments) LengthNonIndexed() int {
+	out := 0
+	for _, arg := range arguments {
+		if !arg.Indexed {
+			out++
+		}
+	}
+	return out
+}
+
+// NonIndexed returns the arguments with indexed arguments filtered out
+func (arguments Arguments) NonIndexed() Arguments {
+	var ret []Argument
+	for _, arg := range arguments {
+		if !arg.Indexed {
+			ret = append(ret, arg)
+		}
+	}
+	return ret
+}
+
+// isTuple returns true for non-atomic constructs, like (uint,uint) or uint[]
+func (arguments Arguments) isTuple() bool {
+	return len(arguments) > 1
+}
+
+// Unpack performs the operation hexdata -> Go format
+func (arguments Arguments) Unpack(v interface{}, data []byte) error {
+	// make sure the passed value is arguments pointer
+	if reflect.Ptr != reflect.ValueOf(v).Kind() {
+		return fmt.Errorf("abi: Unpack(non-pointer %T)", v)
+	}
+	marshalledValues, err := arguments.UnpackValues(data)
+	if err != nil {
+		return err
+	}
+	if arguments.isTuple() {
+		return arguments.unpackTuple(v, marshalledValues)
+	}
+	return arguments.unpackAtomic(v, marshalledValues[0])
+}
+
+// UnpackIntoMap performs the operation hexdata -> mapping of argument name to argument value
+func (arguments Arguments) UnpackIntoMap(v map[string]interface{}, data []byte) error {
+	marshalledValues, err := arguments.UnpackValues(data)
+	if err != nil {
+		return err
+	}
+
+	return arguments.unpackIntoMap(v, marshalledValues)
+}
+
+// unpack sets the unmarshalled value to go format.
+// Note the dst here must be settable.
+func unpack(t *Type, dst interface{}, src interface{}) error {
+	var (
+		dstVal = reflect.ValueOf(dst).Elem()
+		srcVal = reflect.ValueOf(src)
+	)
+
+	if t.T != TupleTy && !((t.T == SliceTy || t.T == ArrayTy) && t.Elem.T == TupleTy) {
+		return set(dstVal, srcVal)
+	}
+
+	switch t.T {
+	case TupleTy:
+		if dstVal.Kind() != reflect.Struct {
+			return fmt.Errorf("abi: invalid dst value for unpack, want struct, got %s", dstVal.Kind())
+		}
+		fieldmap, err := mapArgNamesToStructFields(t.TupleRawNames, dstVal)
+		if err != nil {
+			return err
+		}
+		for i, elem := range t.TupleElems {
+			fname := fieldmap[t.TupleRawNames[i]]
+			field := dstVal.FieldByName(fname)
+			if !field.IsValid() {
+				return fmt.Errorf("abi: field %s can't found in the given value", t.TupleRawNames[i])
+			}
+			if err := unpack(elem, field.Addr().Interface(), srcVal.Field(i).Interface()); err != nil {
+				return err
+			}
+		}
+		return nil
+	case SliceTy:
+		if dstVal.Kind() != reflect.Slice {
+			return fmt.Errorf("abi: invalid dst value for unpack, want slice, got %s", dstVal.Kind())
+		}
+		slice := reflect.MakeSlice(dstVal.Type(), srcVal.Len(), srcVal.Len())
+		for i := 0; i < slice.Len(); i++ {
+			if err := unpack(t.Elem, slice.Index(i).Addr().Interface(), srcVal.Index(i).Interface()); err != nil {
+				return err
+			}
+		}
+		dstVal.Set(slice)
+	case ArrayTy:
+		if dstVal.Kind() != reflect.Array {
+			return fmt.Errorf("abi: invalid dst value for unpack, want array, got %s", dstVal.Kind())
+		}
+		array := reflect.New(dstVal.Type()).Elem()
+		for i := 0; i < array.Len(); i++ {
+			if err := unpack(t.Elem, array.Index(i).Addr().Interface(), srcVal.Index(i).Interface()); err != nil {
+				return err
+			}
+		}
+		dstVal.Set(array)
+	}
+	return nil
+}
+
+// unpackIntoMap unpacks marshalledValues into the provided map[string]interface{}
+func (arguments Arguments) unpackIntoMap(v map[string]interface{}, marshalledValues []interface{}) error {
+	// Make sure map is not nil
+	if v == nil {
+		return fmt.Errorf("abi: cannot unpack into a nil map")
+	}
+
+	for i, arg := range arguments.NonIndexed() {
+		v[arg.Name] = marshalledValues[i]
+	}
+	return nil
+}
+
+// unpackAtomic unpacks ( hexdata -> go ) a single value
+func (arguments Arguments) unpackAtomic(v interface{}, marshalledValues interface{}) error {
+	if arguments.LengthNonIndexed() == 0 {
+		return nil
+	}
+	argument := arguments.NonIndexed()[0]
+	elem := reflect.ValueOf(v).Elem()
+
+	if elem.Kind() == reflect.Struct {
+		fieldmap, err := mapArgNamesToStructFields([]string{argument.Name}, elem)
+		if err != nil {
+			return err
+		}
+		field := elem.FieldByName(fieldmap[argument.Name])
+		if !field.IsValid() {
+			return fmt.Errorf("abi: field %s can't be found in the given value", argument.Name)
+		}
+		return unpack(&argument.Type, field.Addr().Interface(), marshalledValues)
+	}
+	return unpack(&argument.Type, elem.Addr().Interface(), marshalledValues)
+}
+
+// unpackTuple unpacks ( hexdata -> go ) a batch of values.
+func (arguments Arguments) unpackTuple(v interface{}, marshalledValues []interface{}) error {
+	var (
+		value = reflect.ValueOf(v).Elem()
+		typ   = value.Type()
+		kind  = value.Kind()
+	)
+	if err := requireUnpackKind(value, typ, kind, arguments); err != nil {
+		return err
+	}
+
+	// If the interface is a struct, get of abi->struct_field mapping
+	var abi2struct map[string]string
+	if kind == reflect.Struct {
+		var (
+			argNames []string
+			err      error
+		)
+		for _, arg := range arguments.NonIndexed() {
+			argNames = append(argNames, arg.Name)
+		}
+		abi2struct, err = mapArgNamesToStructFields(argNames, value)
+		if err != nil {
+			return err
+		}
+	}
+	for i, arg := range arguments.NonIndexed() {
+		switch kind {
+		case reflect.Struct:
+			field := value.FieldByName(abi2struct[arg.Name])
+			if !field.IsValid() {
+				return fmt.Errorf("abi: field %s can't be found in the given value", arg.Name)
+			}
+			if err := unpack(&arg.Type, field.Addr().Interface(), marshalledValues[i]); err != nil {
+				return err
+			}
+		case reflect.Slice, reflect.Array:
+			if value.Len() < i {
+				return fmt.Errorf("abi: insufficient number of arguments for unpack, want %d, got %d", len(arguments), value.Len())
+			}
+			v := value.Index(i)
+			if err := requireAssignable(v, reflect.ValueOf(marshalledValues[i])); err != nil {
+				return err
+			}
+			if err := unpack(&arg.Type, v.Addr().Interface(), marshalledValues[i]); err != nil {
+				return err
+			}
+		default:
+			return fmt.Errorf("abi:[2] cannot unmarshal tuple in to %v", typ)
+		}
+	}
+	return nil
+
+}
+
+// UnpackValues can be used to unpack ABI-encoded hexdata according to the ABI-specification,
+// without supplying a struct to unpack into. Instead, this method returns a list containing the
+// values. An atomic argument will be a list with one element.
+func (arguments Arguments) UnpackValues(data []byte) ([]interface{}, error) {
+	retval := make([]interface{}, 0, arguments.LengthNonIndexed())
+	virtualArgs := 0
+	for index, arg := range arguments.NonIndexed() {
+		marshalledValue, err := toGoType((index+virtualArgs)*32, arg.Type, data)
+		if arg.Type.T == ArrayTy && !isDynamicType(arg.Type) {
+			// If we have a static array, like [3]uint256, these are coded as
+			// just like uint256,uint256,uint256.
+			// This means that we need to add two 'virtual' arguments when
+			// we count the index from now on.
+			//
+			// Array values nested multiple levels deep are also encoded inline:
+			// [2][3]uint256: uint256,uint256,uint256,uint256,uint256,uint256
+			//
+			// Calculate the full array size to get the correct offset for the next argument.
+			// Decrement it by 1, as the normal index increment is still applied.
+			virtualArgs += getTypeSize(arg.Type)/32 - 1
+		} else if arg.Type.T == TupleTy && !isDynamicType(arg.Type) {
+			// If we have a static tuple, like (uint256, bool, uint256), these are
+			// coded as just like uint256,bool,uint256
+			virtualArgs += getTypeSize(arg.Type)/32 - 1
+		}
+		if err != nil {
+			return nil, err
+		}
+		retval = append(retval, marshalledValue)
+	}
+	return retval, nil
+}
+
+// PackValues performs the operation Go format -> Hexdata
+// It is the semantic opposite of UnpackValues
+func (arguments Arguments) PackValues(args []interface{}) ([]byte, error) {
+	return arguments.Pack(args...)
+}
+
+// Pack performs the operation Go format -> Hexdata
+func (arguments Arguments) Pack(args ...interface{}) ([]byte, error) {
+	// Make sure arguments match up and pack them
+	abiArgs := arguments
+	if len(args) != len(abiArgs) {
+		return nil, fmt.Errorf("argument count mismatch: %d for %d", len(args), len(abiArgs))
+	}
+	// variable input is the output appended at the end of packed
+	// output. This is used for strings and bytes types input.
+	var variableInput []byte
+
+	// input offset is the bytes offset for packed output
+	inputOffset := 0
+	for _, abiArg := range abiArgs {
+		inputOffset += getTypeSize(abiArg.Type)
+	}
+	var ret []byte
+	for i, a := range args {
+		input := abiArgs[i]
+		// pack the input
+		packed, err := input.Type.pack(reflect.ValueOf(a))
+		if err != nil {
+			return nil, err
+		}
+		// check for dynamic types
+		if isDynamicType(input.Type) {
+			// set the offset
+			ret = append(ret, packNum(reflect.ValueOf(inputOffset))...)
+			// calculate next offset
+			inputOffset += len(packed)
+			// append to variable input
+			variableInput = append(variableInput, packed...)
+		} else {
+			// append the packed value to the input
+			ret = append(ret, packed...)
+		}
+	}
+	// append the variable input at the end of the packed input
+	ret = append(ret, variableInput...)
+
+	return ret, nil
+}
+
+// ToCamelCase converts an under-score string to a camel-case string
+func ToCamelCase(input string) string {
+	parts := strings.Split(input, "_")
+	for i, s := range parts {
+		if len(s) > 0 {
+			parts[i] = strings.ToUpper(s[:1]) + s[1:]
+		}
+	}
+	return strings.Join(parts, "")
+}

accounts/abi/bind/auth.go

@@ -0,0 +1,62 @@
+// Copyright 2016 The go-ethereum Authors
+// This file is part of the go-ethereum library.
+//
+// The go-ethereum library is free software: you can redistribute it and/or modify
+// it under the terms of the GNU Lesser General Public License as published by
+// the Free Software Foundation, either version 3 of the License, or
+// (at your option) any later version.
+//
+// The go-ethereum library is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+// GNU Lesser General Public License for more details.
+//
+// You should have received a copy of the GNU Lesser General Public License
+// along with the go-ethereum library. If not, see <http://www.gnu.org/licenses/>.
+
+package bind
+
+import (
+	"crypto/ecdsa"
+	"errors"
+	"io"
+	"io/ioutil"
+
+	"github.com/ethereum/go-ethereum/accounts/keystore"
+	"github.com/ethereum/go-ethereum/common"
+	"github.com/ethereum/go-ethereum/core/types"
+	"github.com/ethereum/go-ethereum/crypto"
+)
+
+// NewTransactor is a utility method to easily create a transaction signer from
+// an encrypted json key stream and the associated passphrase.
+func NewTransactor(keyin io.Reader, passphrase string) (*TransactOpts, error) {
+	json, err := ioutil.ReadAll(keyin)
+	if err != nil {
+		return nil, err
+	}
+	key, err := keystore.DecryptKey(json, passphrase)
+	if err != nil {
+		return nil, err
+	}
+	return NewKeyedTransactor(key.PrivateKey), nil
+}
+
+// NewKeyedTransactor is a utility method to easily create a transaction signer
+// from a single private key.
+func NewKeyedTransactor(key *ecdsa.PrivateKey) *TransactOpts {
+	keyAddr := crypto.PubkeyToAddress(key.PublicKey)
+	return &TransactOpts{
+		From: keyAddr,
+		Signer: func(signer types.Signer, address common.Address, tx *types.Transaction) (*types.Transaction, error) {
+			if address != keyAddr {
+				return nil, errors.New("not authorized to sign this account")
+			}
+			signature, err := crypto.Sign(signer.Hash(tx).Bytes(), key)
+			if err != nil {
+				return nil, err
+			}
+			return tx.WithSignature(signer, signature)
+		},
+	}
+}

accounts/abi/bind/backend.go

@@ -0,0 +1,112 @@
+// Copyright 2015 The go-ethereum Authors
+// This file is part of the go-ethereum library.
+//
+// The go-ethereum library is free software: you can redistribute it and/or modify
+// it under the terms of the GNU Lesser General Public License as published by
+// the Free Software Foundation, either version 3 of the License, or
+// (at your option) any later version.
+//
+// The go-ethereum library is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+// GNU Lesser General Public License for more details.
+//
+// You should have received a copy of the GNU Lesser General Public License
+// along with the go-ethereum library. If not, see <http://www.gnu.org/licenses/>.
+
+package bind
+
+import (
+	"context"
+	"errors"
+	"math/big"
+
+	"github.com/ethereum/go-ethereum"
+	"github.com/ethereum/go-ethereum/common"
+	"github.com/ethereum/go-ethereum/core/types"
+)
+
+var (
+	// ErrNoCode is returned by call and transact operations for which the requested
+	// recipient contract to operate on does not exist in the state db or does not
+	// have any code associated with it (i.e. suicided).
+	ErrNoCode = errors.New("no contract code at given address")
+
+	// This error is raised when attempting to perform a pending state action
+	// on a backend that doesn't implement PendingContractCaller.
+	ErrNoPendingState = errors.New("backend does not support pending state")
+
+	// This error is returned by WaitDeployed if contract creation leaves an
+	// empty contract behind.
+	ErrNoCodeAfterDeploy = errors.New("no contract code after deployment")
+)
+
+// ContractCaller defines the methods needed to allow operating with contract on a read
+// only basis.
+type ContractCaller interface {
+	// CodeAt returns the code of the given account. This is needed to differentiate
+	// between contract internal errors and the local chain being out of sync.
+	CodeAt(ctx context.Context, contract common.Address, blockNumber *big.Int) ([]byte, error)
+	// ContractCall executes an Ethereum contract call with the specified data as the
+	// input.
+	CallContract(ctx context.Context, call ethereum.CallMsg, blockNumber *big.Int) ([]byte, error)
+}
+
+// PendingContractCaller defines methods to perform contract calls on the pending state.
+// Call will try to discover this interface when access to the pending state is requested.
+// If the backend does not support the pending state, Call returns ErrNoPendingState.
+type PendingContractCaller interface {
+	// PendingCodeAt returns the code of the given account in the pending state.
+	PendingCodeAt(ctx context.Context, contract common.Address) ([]byte, error)
+	// PendingCallContract executes an Ethereum contract call against the pending state.
+	PendingCallContract(ctx context.Context, call ethereum.CallMsg) ([]byte, error)
+}
+
+// ContractTransactor defines the methods needed to allow operating with contract
+// on a write only basis. Beside the transacting method, the remainder are helpers
+// used when the user does not provide some needed values, but rather leaves it up
+// to the transactor to decide.
+type ContractTransactor interface {
+	// PendingCodeAt returns the code of the given account in the pending state.
+	PendingCodeAt(ctx context.Context, account common.Address) ([]byte, error)
+	// PendingNonceAt retrieves the current pending nonce associated with an account.
+	PendingNonceAt(ctx context.Context, account common.Address) (uint64, error)
+	// SuggestGasPrice retrieves the currently suggested gas price to allow a timely
+	// execution of a transaction.
+	SuggestGasPrice(ctx context.Context) (*big.Int, error)
+	// EstimateGas tries to estimate the gas needed to execute a specific
+	// transaction based on the current pending state of the backend blockchain.
+	// There is no guarantee that this is the true gas limit requirement as other
+	// transactions may be added or removed by miners, but it should provide a basis
+	// for setting a reasonable default.
+	EstimateGas(ctx context.Context, call ethereum.CallMsg) (gas uint64, err error)
+	// SendTransaction injects the transaction into the pending pool for execution.
+	SendTransaction(ctx context.Context, tx *types.Transaction) error
+}
+
+// ContractFilterer defines the methods needed to access log events using one-off
+// queries or continuous event subscriptions.
+type ContractFilterer interface {
+	// FilterLogs executes a log filter operation, blocking during execution and
+	// returning all the results in one batch.
+	//
+	// TODO(karalabe): Deprecate when the subscription one can return past data too.
+	FilterLogs(ctx context.Context, query ethereum.FilterQuery) ([]types.Log, error)
+
+	// SubscribeFilterLogs creates a background log filtering operation, returning
+	// a subscription immediately, which can be used to stream the found events.
+	SubscribeFilterLogs(ctx context.Context, query ethereum.FilterQuery, ch chan<- types.Log) (ethereum.Subscription, error)
+}
+
+// DeployBackend wraps the operations needed by WaitMined and WaitDeployed.
+type DeployBackend interface {
+	TransactionReceipt(ctx context.Context, txHash common.Hash) (*types.Receipt, error)
+	CodeAt(ctx context.Context, account common.Address, blockNumber *big.Int) ([]byte, error)
+}
+
+// ContractBackend defines the methods needed to work with contracts on a read-write basis.
+type ContractBackend interface {
+	ContractCaller
+	ContractTransactor
+	ContractFilterer
+}

accounts/abi/bind/backends/simulated.go

@@ -0,0 +1,505 @@
+// Copyright 2015 The go-ethereum Authors
+// This file is part of the go-ethereum library.
+//
+// The go-ethereum library is free software: you can redistribute it and/or modify
+// it under the terms of the GNU Lesser General Public License as published by
+// the Free Software Foundation, either version 3 of the License, or
+// (at your option) any later version.
+//
+// The go-ethereum library is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+// GNU Lesser General Public License for more details.
+//
+// You should have received a copy of the GNU Lesser General Public License
+// along with the go-ethereum library. If not, see <http://www.gnu.org/licenses/>.
+
+package backends
+
+import (
+	"context"
+	"errors"
+	"fmt"
+	"math/big"
+	"sync"
+	"time"
+
+	"github.com/ethereum/go-ethereum"
+	"github.com/ethereum/go-ethereum/accounts/abi/bind"
+	"github.com/ethereum/go-ethereum/common"
+	"github.com/ethereum/go-ethereum/common/math"
+	"github.com/ethereum/go-ethereum/consensus/ethash"
+	"github.com/ethereum/go-ethereum/core"
+	"github.com/ethereum/go-ethereum/core/bloombits"
+	"github.com/ethereum/go-ethereum/core/rawdb"
+	"github.com/ethereum/go-ethereum/core/state"
+	"github.com/ethereum/go-ethereum/core/types"
+	"github.com/ethereum/go-ethereum/core/vm"
+	"github.com/ethereum/go-ethereum/eth/filters"
+	"github.com/ethereum/go-ethereum/ethdb"
+	"github.com/ethereum/go-ethereum/event"
+	"github.com/ethereum/go-ethereum/params"
+	"github.com/ethereum/go-ethereum/rpc"
+)
+
+// This nil assignment ensures compile time that SimulatedBackend implements bind.ContractBackend.
+var _ bind.ContractBackend = (*SimulatedBackend)(nil)
+
+var errBlockNumberUnsupported = errors.New("SimulatedBackend cannot access blocks other than the latest block")
+var errGasEstimationFailed = errors.New("gas required exceeds allowance or always failing transaction")
+
+// SimulatedBackend implements bind.ContractBackend, simulating a blockchain in
+// the background. Its main purpose is to allow easily testing contract bindings.
+type SimulatedBackend struct {
+	database   ethdb.Database   // In memory database to store our testing data
+	blockchain *core.BlockChain // Ethereum blockchain to handle the consensus
+
+	mu           sync.Mutex
+	pendingBlock *types.Block   // Currently pending block that will be imported on request
+	pendingState *state.StateDB // Currently pending state that will be the active on on request
+
+	events *filters.EventSystem // Event system for filtering log events live
+
+	config *params.ChainConfig
+}
+
+// NewSimulatedBackend creates a new binding backend using a simulated blockchain
+// for testing purposes.
+func NewSimulatedBackend(alloc core.GenesisAlloc, gasLimit uint64) *SimulatedBackend {
+	database := rawdb.NewMemoryDatabase()
+	genesis := core.Genesis{Config: params.AllEthashProtocolChanges, GasLimit: gasLimit, Alloc: alloc}
+	genesis.MustCommit(database)
+	blockchain, _ := core.NewBlockChain(database, nil, genesis.Config, ethash.NewFaker(), vm.Config{}, nil)
+
+	backend := &SimulatedBackend{
+		database:   database,
+		blockchain: blockchain,
+		config:     genesis.Config,
+		events:     filters.NewEventSystem(new(event.TypeMux), &filterBackend{database, blockchain}, false),
+	}
+	backend.rollback()
+	return backend
+}
+
+// Commit imports all the pending transactions as a single block and starts a
+// fresh new state.
+func (b *SimulatedBackend) Commit() {
+	b.mu.Lock()
+	defer b.mu.Unlock()
+
+	if _, err := b.blockchain.InsertChain([]*types.Block{b.pendingBlock}); err != nil {
+		panic(err) // This cannot happen unless the simulator is wrong, fail in that case
+	}
+	b.rollback()
+}
+
+// Rollback aborts all pending transactions, reverting to the last committed state.
+func (b *SimulatedBackend) Rollback() {
+	b.mu.Lock()
+	defer b.mu.Unlock()
+
+	b.rollback()
+}
+
+func (b *SimulatedBackend) rollback() {
+	blocks, _ := core.GenerateChain(b.config, b.blockchain.CurrentBlock(), ethash.NewFaker(), b.database, 1, func(int, *core.BlockGen) {})
+	statedb, _ := b.blockchain.State()
+
+	b.pendingBlock = blocks[0]
+	b.pendingState, _ = state.New(b.pendingBlock.Root(), statedb.Database())
+}
+
+// CodeAt returns the code associated with a certain account in the blockchain.
+func (b *SimulatedBackend) CodeAt(ctx context.Context, contract common.Address, blockNumber *big.Int) ([]byte, error) {
+	b.mu.Lock()
+	defer b.mu.Unlock()
+
+	if blockNumber != nil && blockNumber.Cmp(b.blockchain.CurrentBlock().Number()) != 0 {
+		return nil, errBlockNumberUnsupported
+	}
+	statedb, _ := b.blockchain.State()
+	return statedb.GetCode(contract), nil
+}
+
+// BalanceAt returns the wei balance of a certain account in the blockchain.
+func (b *SimulatedBackend) BalanceAt(ctx context.Context, contract common.Address, blockNumber *big.Int) (*big.Int, error) {
+	b.mu.Lock()
+	defer b.mu.Unlock()
+
+	if blockNumber != nil && blockNumber.Cmp(b.blockchain.CurrentBlock().Number()) != 0 {
+		return nil, errBlockNumberUnsupported
+	}
+	statedb, _ := b.blockchain.State()
+	return statedb.GetBalance(contract), nil
+}
+
+// NonceAt returns the nonce of a certain account in the blockchain.
+func (b *SimulatedBackend) NonceAt(ctx context.Context, contract common.Address, blockNumber *big.Int) (uint64, error) {
+	b.mu.Lock()
+	defer b.mu.Unlock()
+
+	if blockNumber != nil && blockNumber.Cmp(b.blockchain.CurrentBlock().Number()) != 0 {
+		return 0, errBlockNumberUnsupported
+	}
+	statedb, _ := b.blockchain.State()
+	return statedb.GetNonce(contract), nil
+}
+
+// StorageAt returns the value of key in the storage of an account in the blockchain.
+func (b *SimulatedBackend) StorageAt(ctx context.Context, contract common.Address, key common.Hash, blockNumber *big.Int) ([]byte, error) {
+	b.mu.Lock()
+	defer b.mu.Unlock()
+
+	if blockNumber != nil && blockNumber.Cmp(b.blockchain.CurrentBlock().Number()) != 0 {
+		return nil, errBlockNumberUnsupported
+	}
+	statedb, _ := b.blockchain.State()
+	val := statedb.GetState(contract, key)
+	return val[:], nil
+}
+
+// TransactionReceipt returns the receipt of a transaction.
+func (b *SimulatedBackend) TransactionReceipt(ctx context.Context, txHash common.Hash) (*types.Receipt, error) {
+	receipt, _, _, _ := rawdb.ReadReceipt(b.database, txHash, b.config)
+	return receipt, nil
+}
+
+// TransactionByHash checks the pool of pending transactions in addition to the
+// blockchain. The isPending return value indicates whether the transaction has been
+// mined yet. Note that the transaction may not be part of the canonical chain even if
+// it's not pending.
+func (b *SimulatedBackend) TransactionByHash(ctx context.Context, txHash common.Hash) (*types.Transaction, bool, error) {
+	b.mu.Lock()
+	defer b.mu.Unlock()
+
+	tx := b.pendingBlock.Transaction(txHash)
+	if tx != nil {
+		return tx, true, nil
+	}
+	tx, _, _, _ = rawdb.ReadTransaction(b.database, txHash)
+	if tx != nil {
+		return tx, false, nil
+	}
+	return nil, false, ethereum.NotFound
+}
+
+// PendingCodeAt returns the code associated with an account in the pending state.
+func (b *SimulatedBackend) PendingCodeAt(ctx context.Context, contract common.Address) ([]byte, error) {
+	b.mu.Lock()
+	defer b.mu.Unlock()
+
+	return b.pendingState.GetCode(contract), nil
+}
+
+// CallContract executes a contract call.
+func (b *SimulatedBackend) CallContract(ctx context.Context, call ethereum.CallMsg, blockNumber *big.Int) ([]byte, error) {
+	b.mu.Lock()
+	defer b.mu.Unlock()
+
+	if blockNumber != nil && blockNumber.Cmp(b.blockchain.CurrentBlock().Number()) != 0 {
+		return nil, errBlockNumberUnsupported
+	}
+	state, err := b.blockchain.State()
+	if err != nil {
+		return nil, err
+	}
+	rval, _, _, err := b.callContract(ctx, call, b.blockchain.CurrentBlock(), state)
+	return rval, err
+}
+
+// PendingCallContract executes a contract call on the pending state.
+func (b *SimulatedBackend) PendingCallContract(ctx context.Context, call ethereum.CallMsg) ([]byte, error) {
+	b.mu.Lock()
+	defer b.mu.Unlock()
+	defer b.pendingState.RevertToSnapshot(b.pendingState.Snapshot())
+
+	rval, _, _, err := b.callContract(ctx, call, b.pendingBlock, b.pendingState)
+	return rval, err
+}
+
+// PendingNonceAt implements PendingStateReader.PendingNonceAt, retrieving
+// the nonce currently pending for the account.
+func (b *SimulatedBackend) PendingNonceAt(ctx context.Context, account common.Address) (uint64, error) {
+	b.mu.Lock()
+	defer b.mu.Unlock()
+
+	return b.pendingState.GetOrNewStateObject(account).Nonce(), nil
+}
+
+// SuggestGasPrice implements ContractTransactor.SuggestGasPrice. Since the simulated
+// chain doesn't have miners, we just return a gas price of 1 for any call.
+func (b *SimulatedBackend) SuggestGasPrice(ctx context.Context) (*big.Int, error) {
+	return big.NewInt(1), nil
+}
+
+// EstimateGas executes the requested code against the currently pending block/state and
+// returns the used amount of gas.
+func (b *SimulatedBackend) EstimateGas(ctx context.Context, call ethereum.CallMsg) (uint64, error) {
+	b.mu.Lock()
+	defer b.mu.Unlock()
+
+	// Determine the lowest and highest possible gas limits to binary search in between
+	var (
+		lo  uint64 = params.TxGas - 1
+		hi  uint64
+		cap uint64
+	)
+	if call.Gas >= params.TxGas {
+		hi = call.Gas
+	} else {
+		hi = b.pendingBlock.GasLimit()
+	}
+	cap = hi
+
+	// Create a helper to check if a gas allowance results in an executable transaction
+	executable := func(gas uint64) bool {
+		call.Gas = gas
+
+		snapshot := b.pendingState.Snapshot()
+		_, _, failed, err := b.callContract(ctx, call, b.pendingBlock, b.pendingState)
+		b.pendingState.RevertToSnapshot(snapshot)
+
+		if err != nil || failed {
+			return false
+		}
+		return true
+	}
+	// Execute the binary search and hone in on an executable gas limit
+	for lo+1 < hi {
+		mid := (hi + lo) / 2
+		if !executable(mid) {
+			lo = mid
+		} else {
+			hi = mid
+		}
+	}
+	// Reject the transaction as invalid if it still fails at the highest allowance
+	if hi == cap {
+		if !executable(hi) {
+			return 0, errGasEstimationFailed
+		}
+	}
+	return hi, nil
+}
+
+// callContract implements common code between normal and pending contract calls.
+// state is modified during execution, make sure to copy it if necessary.
+func (b *SimulatedBackend) callContract(ctx context.Context, call ethereum.CallMsg, block *types.Block, statedb *state.StateDB) ([]byte, uint64, bool, error) {
+	// Ensure message is initialized properly.
+	if call.GasPrice == nil {
+		call.GasPrice = big.NewInt(1)
+	}
+	if call.Gas == 0 {
+		call.Gas = 50000000
+	}
+	if call.Value == nil {
+		call.Value = new(big.Int)
+	}
+	// Set infinite balance to the fake caller account.
+	from := statedb.GetOrNewStateObject(call.From)
+	from.SetBalance(math.MaxBig256)
+	// Execute the call.
+	msg := callmsg{call}
+
+	evmContext := core.NewEVMContext(msg, block.Header(), b.blockchain, nil)
+	// Create a new environment which holds all relevant information
+	// about the transaction and calling mechanisms.
+	vmenv := vm.NewEVM(evmContext, statedb, b.config, vm.Config{})
+	gaspool := new(core.GasPool).AddGas(math.MaxUint64)
+
+	return core.NewStateTransition(vmenv, msg, gaspool).TransitionDb()
+}
+
+// SendTransaction updates the pending block to include the given transaction.
+// It panics if the transaction is invalid.
+func (b *SimulatedBackend) SendTransaction(ctx context.Context, tx *types.Transaction) error {
+	b.mu.Lock()
+	defer b.mu.Unlock()
+
+	sender, err := types.Sender(types.HomesteadSigner{}, tx)
+	if err != nil {
+		panic(fmt.Errorf("invalid transaction: %v", err))
+	}
+	nonce := b.pendingState.GetNonce(sender)
+	if tx.Nonce() != nonce {
+		panic(fmt.Errorf("invalid transaction nonce: got %d, want %d", tx.Nonce(), nonce))
+	}
+
+	blocks, _ := core.GenerateChain(b.config, b.blockchain.CurrentBlock(), ethash.NewFaker(), b.database, 1, func(number int, block *core.BlockGen) {
+		for _, tx := range b.pendingBlock.Transactions() {
+			block.AddTxWithChain(b.blockchain, tx)
+		}
+		block.AddTxWithChain(b.blockchain, tx)
+	})
+	statedb, _ := b.blockchain.State()
+
+	b.pendingBlock = blocks[0]
+	b.pendingState, _ = state.New(b.pendingBlock.Root(), statedb.Database())
+	return nil
+}
+
+// FilterLogs executes a log filter operation, blocking during execution and
+// returning all the results in one batch.
+//
+// TODO(karalabe): Deprecate when the subscription one can return past data too.
+func (b *SimulatedBackend) FilterLogs(ctx context.Context, query ethereum.FilterQuery) ([]types.Log, error) {
+	var filter *filters.Filter
+	if query.BlockHash != nil {
+		// Block filter requested, construct a single-shot filter
+		filter = filters.NewBlockFilter(&filterBackend{b.database, b.blockchain}, *query.BlockHash, query.Addresses, query.Topics)
+	} else {
+		// Initialize unset filter boundaried to run from genesis to chain head
+		from := int64(0)
+		if query.FromBlock != nil {
+			from = query.FromBlock.Int64()
+		}
+		to := int64(-1)
+		if query.ToBlock != nil {
+			to = query.ToBlock.Int64()
+		}
+		// Construct the range filter
+		filter = filters.NewRangeFilter(&filterBackend{b.database, b.blockchain}, from, to, query.Addresses, query.Topics)
+	}
+	// Run the filter and return all the logs
+	logs, err := filter.Logs(ctx)
+	if err != nil {
+		return nil, err
+	}
+	res := make([]types.Log, len(logs))
+	for i, log := range logs {
+		res[i] = *log
+	}
+	return res, nil
+}
+
+// SubscribeFilterLogs creates a background log filtering operation, returning a
+// subscription immediately, which can be used to stream the found events.
+func (b *SimulatedBackend) SubscribeFilterLogs(ctx context.Context, query ethereum.FilterQuery, ch chan<- types.Log) (ethereum.Subscription, error) {
+	// Subscribe to contract events
+	sink := make(chan []*types.Log)
+
+	sub, err := b.events.SubscribeLogs(query, sink)
+	if err != nil {
+		return nil, err
+	}
+	// Since we're getting logs in batches, we need to flatten them into a plain stream
+	return event.NewSubscription(func(quit <-chan struct{}) error {
+		defer sub.Unsubscribe()
+		for {
+			select {
+			case logs := <-sink:
+				for _, log := range logs {
+					select {
+					case ch <- *log:
+					case err := <-sub.Err():
+						return err
+					case <-quit:
+						return nil
+					}
+				}
+			case err := <-sub.Err():
+				return err
+			case <-quit:
+				return nil
+			}
+		}
+	}), nil
+}
+
+// AdjustTime adds a time shift to the simulated clock.
+func (b *SimulatedBackend) AdjustTime(adjustment time.Duration) error {
+	b.mu.Lock()
+	defer b.mu.Unlock()
+	blocks, _ := core.GenerateChain(b.config, b.blockchain.CurrentBlock(), ethash.NewFaker(), b.database, 1, func(number int, block *core.BlockGen) {
+		for _, tx := range b.pendingBlock.Transactions() {
+			block.AddTx(tx)
+		}
+		block.OffsetTime(int64(adjustment.Seconds()))
+	})
+	statedb, _ := b.blockchain.State()
+
+	b.pendingBlock = blocks[0]
+	b.pendingState, _ = state.New(b.pendingBlock.Root(), statedb.Database())
+
+	return nil
+}
+
+// callmsg implements core.Message to allow passing it as a transaction simulator.
+type callmsg struct {
+	ethereum.CallMsg
+}
+
+func (m callmsg) From() common.Address { return m.CallMsg.From }
+func (m callmsg) Nonce() uint64        { return 0 }
+func (m callmsg) CheckNonce() bool     { return false }
+func (m callmsg) To() *common.Address  { return m.CallMsg.To }
+func (m callmsg) GasPrice() *big.Int   { return m.CallMsg.GasPrice }
+func (m callmsg) Gas() uint64          { return m.CallMsg.Gas }
+func (m callmsg) Value() *big.Int      { return m.CallMsg.Value }
+func (m callmsg) Data() []byte         { return m.CallMsg.Data }
+
+// filterBackend implements filters.Backend to support filtering for logs without
+// taking bloom-bits acceleration structures into account.
+type filterBackend struct {
+	db ethdb.Database
+	bc *core.BlockChain
+}
+
+func (fb *filterBackend) ChainDb() ethdb.Database  { return fb.db }
+func (fb *filterBackend) EventMux() *event.TypeMux { panic("not supported") }
+
+func (fb *filterBackend) HeaderByNumber(ctx context.Context, block rpc.BlockNumber) (*types.Header, error) {
+	if block == rpc.LatestBlockNumber {
+		return fb.bc.CurrentHeader(), nil
+	}
+	return fb.bc.GetHeaderByNumber(uint64(block.Int64())), nil
+}
+
+func (fb *filterBackend) HeaderByHash(ctx context.Context, hash common.Hash) (*types.Header, error) {
+	return fb.bc.GetHeaderByHash(hash), nil
+}
+
+func (fb *filterBackend) GetReceipts(ctx context.Context, hash common.Hash) (types.Receipts, error) {
+	number := rawdb.ReadHeaderNumber(fb.db, hash)
+	if number == nil {
+		return nil, nil
+	}
+	return rawdb.ReadReceipts(fb.db, hash, *number, fb.bc.Config()), nil
+}
+
+func (fb *filterBackend) GetLogs(ctx context.Context, hash common.Hash) ([][]*types.Log, error) {
+	number := rawdb.ReadHeaderNumber(fb.db, hash)
+	if number == nil {
+		return nil, nil
+	}
+	receipts := rawdb.ReadReceipts(fb.db, hash, *number, fb.bc.Config())
+	if receipts == nil {
+		return nil, nil
+	}
+	logs := make([][]*types.Log, len(receipts))
+	for i, receipt := range receipts {
+		logs[i] = receipt.Logs
+	}
+	return logs, nil
+}
+
+func (fb *filterBackend) SubscribeNewTxsEvent(ch chan<- core.NewTxsEvent) event.Subscription {
+	return event.NewSubscription(func(quit <-chan struct{}) error {
+		<-quit
+		return nil
+	})
+}
+func (fb *filterBackend) SubscribeChainEvent(ch chan<- core.ChainEvent) event.Subscription {
+	return fb.bc.SubscribeChainEvent(ch)
+}
+func (fb *filterBackend) SubscribeRemovedLogsEvent(ch chan<- core.RemovedLogsEvent) event.Subscription {
+	return fb.bc.SubscribeRemovedLogsEvent(ch)
+}
+func (fb *filterBackend) SubscribeLogsEvent(ch chan<- []*types.Log) event.Subscription {
+	return fb.bc.SubscribeLogsEvent(ch)
+}
+
+func (fb *filterBackend) BloomStatus() (uint64, uint64) { return 4096, 0 }
+func (fb *filterBackend) ServiceFilter(ctx context.Context, ms *bloombits.MatcherSession) {
+	panic("not supported")
+}

accounts/abi/bind/backends/simulated_test.go

@@ -0,0 +1,82 @@
+// Copyright 2019 The go-ethereum Authors
+// This file is part of the go-ethereum library.
+//
+// The go-ethereum library is free software: you can redistribute it and/or modify
+// it under the terms of the GNU Lesser General Public License as published by
+// the Free Software Foundation, either version 3 of the License, or
+// (at your option) any later version.
+//
+// The go-ethereum library is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+// GNU Lesser General Public License for more details.
+//
+// You should have received a copy of the GNU Lesser General Public License
+// along with the go-ethereum library. If not, see <http://www.gnu.org/licenses/>.
+
+package backends_test
+
+import (
+	"context"
+	"math/big"
+	"testing"
+
+	ethereum "github.com/ethereum/go-ethereum"
+	"github.com/ethereum/go-ethereum/accounts/abi/bind"
+	"github.com/ethereum/go-ethereum/accounts/abi/bind/backends"
+	"github.com/ethereum/go-ethereum/common"
+	"github.com/ethereum/go-ethereum/core"
+	"github.com/ethereum/go-ethereum/core/types"
+	"github.com/ethereum/go-ethereum/crypto"
+)
+
+func TestSimulatedBackend(t *testing.T) {
+	var gasLimit uint64 = 8000029
+	key, _ := crypto.GenerateKey() // nolint: gosec
+	auth := bind.NewKeyedTransactor(key)
+	genAlloc := make(core.GenesisAlloc)
+	genAlloc[auth.From] = core.GenesisAccount{Balance: big.NewInt(9223372036854775807)}
+
+	sim := backends.NewSimulatedBackend(genAlloc, gasLimit)
+
+	// should return an error if the tx is not found
+	txHash := common.HexToHash("2")
+	_, isPending, err := sim.TransactionByHash(context.Background(), txHash)
+
+	if isPending {
+		t.Fatal("transaction should not be pending")
+	}
+	if err != ethereum.NotFound {
+		t.Fatalf("err should be `ethereum.NotFound` but received %v", err)
+	}
+
+	// generate a transaction and confirm you can retrieve it
+	code := `6060604052600a8060106000396000f360606040526008565b00`
+	var gas uint64 = 3000000
+	tx := types.NewContractCreation(0, big.NewInt(0), gas, big.NewInt(1), common.FromHex(code))
+	tx, _ = types.SignTx(tx, types.HomesteadSigner{}, key)
+
+	err = sim.SendTransaction(context.Background(), tx)
+	if err != nil {
+		t.Fatal("error sending transaction")
+	}
+
+	txHash = tx.Hash()
+	_, isPending, err = sim.TransactionByHash(context.Background(), txHash)
+	if err != nil {
+		t.Fatalf("error getting transaction with hash: %v", txHash.String())
+	}
+	if !isPending {
+		t.Fatal("transaction should have pending status")
+	}
+
+	sim.Commit()
+	tx, isPending, err = sim.TransactionByHash(context.Background(), txHash)
+	if err != nil {
+		t.Fatalf("error getting transaction with hash: %v", txHash.String())
+	}
+	if isPending {
+		t.Fatal("transaction should not have pending status")
+	}
+
+}

accounts/abi/bind/base.go

@@ -0,0 +1,366 @@
+// Copyright 2015 The go-ethereum Authors
+// This file is part of the go-ethereum library.
+//
+// The go-ethereum library is free software: you can redistribute it and/or modify
+// it under the terms of the GNU Lesser General Public License as published by
+// the Free Software Foundation, either version 3 of the License, or
+// (at your option) any later version.
+//
+// The go-ethereum library is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+// GNU Lesser General Public License for more details.
+//
+// You should have received a copy of the GNU Lesser General Public License
+// along with the go-ethereum library. If not, see <http://www.gnu.org/licenses/>.
+
+package bind
+
+import (
+	"context"
+	"errors"
+	"fmt"
+	"math/big"
+
+	"github.com/ethereum/go-ethereum"
+	"github.com/ethereum/go-ethereum/accounts/abi"
+	"github.com/ethereum/go-ethereum/common"
+	"github.com/ethereum/go-ethereum/core/types"
+	"github.com/ethereum/go-ethereum/crypto"
+	"github.com/ethereum/go-ethereum/event"
+)
+
+// SignerFn is a signer function callback when a contract requires a method to
+// sign the transaction before submission.
+type SignerFn func(types.Signer, common.Address, *types.Transaction) (*types.Transaction, error)
+
+// CallOpts is the collection of options to fine tune a contract call request.
+type CallOpts struct {
+	Pending     bool            // Whether to operate on the pending state or the last known one
+	From        common.Address  // Optional the sender address, otherwise the first account is used
+	BlockNumber *big.Int        // Optional the block number on which the call should be performed
+	Context     context.Context // Network context to support cancellation and timeouts (nil = no timeout)
+}
+
+// TransactOpts is the collection of authorization data required to create a
+// valid Ethereum transaction.
+type TransactOpts struct {
+	From   common.Address // Ethereum account to send the transaction from
+	Nonce  *big.Int       // Nonce to use for the transaction execution (nil = use pending state)
+	Signer SignerFn       // Method to use for signing the transaction (mandatory)
+
+	Value    *big.Int // Funds to transfer along along the transaction (nil = 0 = no funds)
+	GasPrice *big.Int // Gas price to use for the transaction execution (nil = gas price oracle)
+	GasLimit uint64   // Gas limit to set for the transaction execution (0 = estimate)
+
+	Context context.Context // Network context to support cancellation and timeouts (nil = no timeout)
+}
+
+// FilterOpts is the collection of options to fine tune filtering for events
+// within a bound contract.
+type FilterOpts struct {
+	Start uint64  // Start of the queried range
+	End   *uint64 // End of the range (nil = latest)
+
+	Context context.Context // Network context to support cancellation and timeouts (nil = no timeout)
+}
+
+// WatchOpts is the collection of options to fine tune subscribing for events
+// within a bound contract.
+type WatchOpts struct {
+	Start   *uint64         // Start of the queried range (nil = latest)
+	Context context.Context // Network context to support cancellation and timeouts (nil = no timeout)
+}
+
+// BoundContract is the base wrapper object that reflects a contract on the
+// Ethereum network. It contains a collection of methods that are used by the
+// higher level contract bindings to operate.
+type BoundContract struct {
+	address    common.Address     // Deployment address of the contract on the Ethereum blockchain
+	abi        abi.ABI            // Reflect based ABI to access the correct Ethereum methods
+	caller     ContractCaller     // Read interface to interact with the blockchain
+	transactor ContractTransactor // Write interface to interact with the blockchain
+	filterer   ContractFilterer   // Event filtering to interact with the blockchain
+}
+
+// NewBoundContract creates a low level contract interface through which calls
+// and transactions may be made through.
+func NewBoundContract(address common.Address, abi abi.ABI, caller ContractCaller, transactor ContractTransactor, filterer ContractFilterer) *BoundContract {
+	return &BoundContract{
+		address:    address,
+		abi:        abi,
+		caller:     caller,
+		transactor: transactor,
+		filterer:   filterer,
+	}
+}
+
+// DeployContract deploys a contract onto the Ethereum blockchain and binds the
+// deployment address with a Go wrapper.
+func DeployContract(opts *TransactOpts, abi abi.ABI, bytecode []byte, backend ContractBackend, params ...interface{}) (common.Address, *types.Transaction, *BoundContract, error) {
+	// Otherwise try to deploy the contract
+	c := NewBoundContract(common.Address{}, abi, backend, backend, backend)
+
+	input, err := c.abi.Pack("", params...)
+	if err != nil {
+		return common.Address{}, nil, nil, err
+	}
+	tx, err := c.transact(opts, nil, append(bytecode, input...))
+	if err != nil {
+		return common.Address{}, nil, nil, err
+	}
+	c.address = crypto.CreateAddress(opts.From, tx.Nonce())
+	return c.address, tx, c, nil
+}
+
+// Call invokes the (constant) contract method with params as input values and
+// sets the output to result. The result type might be a single field for simple
+// returns, a slice of interfaces for anonymous returns and a struct for named
+// returns.
+func (c *BoundContract) Call(opts *CallOpts, result interface{}, method string, params ...interface{}) error {
+	// Don't crash on a lazy user
+	if opts == nil {
+		opts = new(CallOpts)
+	}
+	// Pack the input, call and unpack the results
+	input, err := c.abi.Pack(method, params...)
+	if err != nil {
+		return err
+	}
+	var (
+		msg    = ethereum.CallMsg{From: opts.From, To: &c.address, Data: input}
+		ctx    = ensureContext(opts.Context)
+		code   []byte
+		output []byte
+	)
+	if opts.Pending {
+		pb, ok := c.caller.(PendingContractCaller)
+		if !ok {
+			return ErrNoPendingState
+		}
+		output, err = pb.PendingCallContract(ctx, msg)
+		if err == nil && len(output) == 0 {
+			// Make sure we have a contract to operate on, and bail out otherwise.
+			if code, err = pb.PendingCodeAt(ctx, c.address); err != nil {
+				return err
+			} else if len(code) == 0 {
+				return ErrNoCode
+			}
+		}
+	} else {
+		output, err = c.caller.CallContract(ctx, msg, opts.BlockNumber)
+		if err == nil && len(output) == 0 {
+			// Make sure we have a contract to operate on, and bail out otherwise.
+			if code, err = c.caller.CodeAt(ctx, c.address, opts.BlockNumber); err != nil {
+				return err
+			} else if len(code) == 0 {
+				return ErrNoCode
+			}
+		}
+	}
+	if err != nil {
+		return err
+	}
+	return c.abi.Unpack(result, method, output)
+}
+
+// Transact invokes the (paid) contract method with params as input values.
+func (c *BoundContract) Transact(opts *TransactOpts, method string, params ...interface{}) (*types.Transaction, error) {
+	// Otherwise pack up the parameters and invoke the contract
+	input, err := c.abi.Pack(method, params...)
+	if err != nil {
+		return nil, err
+	}
+	return c.transact(opts, &c.address, input)
+}
+
+// Transfer initiates a plain transaction to move funds to the contract, calling
+// its default method if one is available.
+func (c *BoundContract) Transfer(opts *TransactOpts) (*types.Transaction, error) {
+	return c.transact(opts, &c.address, nil)
+}
+
+// transact executes an actual transaction invocation, first deriving any missing
+// authorization fields, and then scheduling the transaction for execution.
+func (c *BoundContract) transact(opts *TransactOpts, contract *common.Address, input []byte) (*types.Transaction, error) {
+	var err error
+
+	// Ensure a valid value field and resolve the account nonce
+	value := opts.Value
+	if value == nil {
+		value = new(big.Int)
+	}
+	var nonce uint64
+	if opts.Nonce == nil {
+		nonce, err = c.transactor.PendingNonceAt(ensureContext(opts.Context), opts.From)
+		if err != nil {
+			return nil, fmt.Errorf("failed to retrieve account nonce: %v", err)
+		}
+	} else {
+		nonce = opts.Nonce.Uint64()
+	}
+	// Figure out the gas allowance and gas price values
+	gasPrice := opts.GasPrice
+	if gasPrice == nil {
+		gasPrice, err = c.transactor.SuggestGasPrice(ensureContext(opts.Context))
+		if err != nil {
+			return nil, fmt.Errorf("failed to suggest gas price: %v", err)
+		}
+	}
+	gasLimit := opts.GasLimit
+	if gasLimit == 0 {
+		// Gas estimation cannot succeed without code for method invocations
+		if contract != nil {
+			if code, err := c.transactor.PendingCodeAt(ensureContext(opts.Context), c.address); err != nil {
+				return nil, err
+			} else if len(code) == 0 {
+				return nil, ErrNoCode
+			}
+		}
+		// If the contract surely has code (or code is not needed), estimate the transaction
+		msg := ethereum.CallMsg{From: opts.From, To: contract, Value: value, Data: input}
+		gasLimit, err = c.transactor.EstimateGas(ensureContext(opts.Context), msg)
+		if err != nil {
+			return nil, fmt.Errorf("failed to estimate gas needed: %v", err)
+		}
+	}
+	// Create the transaction, sign it and schedule it for execution
+	var rawTx *types.Transaction
+	if contract == nil {
+		rawTx = types.NewContractCreation(nonce, value, gasLimit, gasPrice, input)
+	} else {
+		rawTx = types.NewTransaction(nonce, c.address, value, gasLimit, gasPrice, input)
+	}
+	if opts.Signer == nil {
+		return nil, errors.New("no signer to authorize the transaction with")
+	}
+	signedTx, err := opts.Signer(types.HomesteadSigner{}, opts.From, rawTx)
+	if err != nil {
+		return nil, err
+	}
+	if err := c.transactor.SendTransaction(ensureContext(opts.Context), signedTx); err != nil {
+		return nil, err
+	}
+	return signedTx, nil
+}
+
+// FilterLogs filters contract logs for past blocks, returning the necessary
+// channels to construct a strongly typed bound iterator on top of them.
+func (c *BoundContract) FilterLogs(opts *FilterOpts, name string, query ...[]interface{}) (chan types.Log, event.Subscription, error) {
+	// Don't crash on a lazy user
+	if opts == nil {
+		opts = new(FilterOpts)
+	}
+	// Append the event selector to the query parameters and construct the topic set
+	query = append([][]interface{}{{c.abi.Events[name].Id()}}, query...)
+
+	topics, err := makeTopics(query...)
+	if err != nil {
+		return nil, nil, err
+	}
+	// Start the background filtering
+	logs := make(chan types.Log, 128)
+
+	config := ethereum.FilterQuery{
+		Addresses: []common.Address{c.address},
+		Topics:    topics,
+		FromBlock: new(big.Int).SetUint64(opts.Start),
+	}
+	if opts.End != nil {
+		config.ToBlock = new(big.Int).SetUint64(*opts.End)
+	}
+	/* TODO(karalabe): Replace the rest of the method below with this when supported
+	sub, err := c.filterer.SubscribeFilterLogs(ensureContext(opts.Context), config, logs)
+	*/
+	buff, err := c.filterer.FilterLogs(ensureContext(opts.Context), config)
+	if err != nil {
+		return nil, nil, err
+	}
+	sub, err := event.NewSubscription(func(quit <-chan struct{}) error {
+		for _, log := range buff {
+			select {
+			case logs <- log:
+			case <-quit:
+				return nil
+			}
+		}
+		return nil
+	}), nil
+
+	if err != nil {
+		return nil, nil, err
+	}
+	return logs, sub, nil
+}
+
+// WatchLogs filters subscribes to contract logs for future blocks, returning a
+// subscription object that can be used to tear down the watcher.
+func (c *BoundContract) WatchLogs(opts *WatchOpts, name string, query ...[]interface{}) (chan types.Log, event.Subscription, error) {
+	// Don't crash on a lazy user
+	if opts == nil {
+		opts = new(WatchOpts)
+	}
+	// Append the event selector to the query parameters and construct the topic set
+	query = append([][]interface{}{{c.abi.Events[name].Id()}}, query...)
+
+	topics, err := makeTopics(query...)
+	if err != nil {
+		return nil, nil, err
+	}
+	// Start the background filtering
+	logs := make(chan types.Log, 128)
+
+	config := ethereum.FilterQuery{
+		Addresses: []common.Address{c.address},
+		Topics:    topics,
+	}
+	if opts.Start != nil {
+		config.FromBlock = new(big.Int).SetUint64(*opts.Start)
+	}
+	sub, err := c.filterer.SubscribeFilterLogs(ensureContext(opts.Context), config, logs)
+	if err != nil {
+		return nil, nil, err
+	}
+	return logs, sub, nil
+}
+
+// UnpackLog unpacks a retrieved log into the provided output structure.
+func (c *BoundContract) UnpackLog(out interface{}, event string, log types.Log) error {
+	if len(log.Data) > 0 {
+		if err := c.abi.Unpack(out, event, log.Data); err != nil {
+			return err
+		}
+	}
+	var indexed abi.Arguments
+	for _, arg := range c.abi.Events[event].Inputs {
+		if arg.Indexed {
+			indexed = append(indexed, arg)
+		}
+	}
+	return parseTopics(out, indexed, log.Topics[1:])
+}
+
+// UnpackLogIntoMap unpacks a retrieved log into the provided map.
+func (c *BoundContract) UnpackLogIntoMap(out map[string]interface{}, event string, log types.Log) error {
+	if len(log.Data) > 0 {
+		if err := c.abi.UnpackIntoMap(out, event, log.Data); err != nil {
+			return err
+		}
+	}
+	var indexed abi.Arguments
+	for _, arg := range c.abi.Events[event].Inputs {
+		if arg.Indexed {
+			indexed = append(indexed, arg)
+		}
+	}
+	return parseTopicsIntoMap(out, indexed, log.Topics[1:])
+}
+
+// ensureContext is a helper method to ensure a context is not nil, even if the
+// user specified it as such.
+func ensureContext(ctx context.Context) context.Context {
+	if ctx == nil {
+		return context.TODO()
+	}
+	return ctx
+}

accounts/abi/bind/base_test.go

@@ -0,0 +1,373 @@
+// Copyright 2019 The go-ethereum Authors
+// This file is part of the go-ethereum library.
+//
+// The go-ethereum library is free software: you can redistribute it and/or modify
+// it under the terms of the GNU Lesser General Public License as published by
+// the Free Software Foundation, either version 3 of the License, or
+// (at your option) any later version.
+//
+// The go-ethereum library is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+// GNU Lesser General Public License for more details.
+//
+// You should have received a copy of the GNU Lesser General Public License
+// along with the go-ethereum library. If not, see <http://www.gnu.org/licenses/>.
+
+package bind_test
+
+import (
+	"bytes"
+	"context"
+	"math/big"
+	"strings"
+	"testing"
+
+	"github.com/ethereum/go-ethereum"
+	"github.com/ethereum/go-ethereum/accounts/abi"
+	"github.com/ethereum/go-ethereum/accounts/abi/bind"
+	"github.com/ethereum/go-ethereum/common"
+	"github.com/ethereum/go-ethereum/common/hexutil"
+	"github.com/ethereum/go-ethereum/core/types"
+	"github.com/ethereum/go-ethereum/crypto"
+	"github.com/ethereum/go-ethereum/rlp"
+)
+
+type mockCaller struct {
+	codeAtBlockNumber       *big.Int
+	callContractBlockNumber *big.Int
+}
+
+func (mc *mockCaller) CodeAt(ctx context.Context, contract common.Address, blockNumber *big.Int) ([]byte, error) {
+	mc.codeAtBlockNumber = blockNumber
+	return []byte{1, 2, 3}, nil
+}
+
+func (mc *mockCaller) CallContract(ctx context.Context, call ethereum.CallMsg, blockNumber *big.Int) ([]byte, error) {
+	mc.callContractBlockNumber = blockNumber
+	return nil, nil
+}
+func TestPassingBlockNumber(t *testing.T) {
+
+	mc := &mockCaller{}
+
+	bc := bind.NewBoundContract(common.HexToAddress("0x0"), abi.ABI{
+		Methods: map[string]abi.Method{
+			"something": {
+				Name:    "something",
+				Outputs: abi.Arguments{},
+			},
+		},
+	}, mc, nil, nil)
+	var ret string
+
+	blockNumber := big.NewInt(42)
+
+	bc.Call(&bind.CallOpts{BlockNumber: blockNumber}, &ret, "something")
+
+	if mc.callContractBlockNumber != blockNumber {
+		t.Fatalf("CallContract() was not passed the block number")
+	}
+
+	if mc.codeAtBlockNumber != blockNumber {
+		t.Fatalf("CodeAt() was not passed the block number")
+	}
+
+	bc.Call(&bind.CallOpts{}, &ret, "something")
+
+	if mc.callContractBlockNumber != nil {
+		t.Fatalf("CallContract() was passed a block number when it should not have been")
+	}
+
+	if mc.codeAtBlockNumber != nil {
+		t.Fatalf("CodeAt() was passed a block number when it should not have been")
+	}
+}
+
+const hexData = "0x000000000000000000000000376c47978271565f56deb45495afa69e59c16ab200000000000000000000000000000000000000000000000000000000000000010000000000000000000000000000000000000000000000000000000000000060000000000000000000000000000000000000000000000000000000000000000158"
+
+func TestUnpackIndexedStringTyLogIntoMap(t *testing.T) {
+	hash := crypto.Keccak256Hash([]byte("testName"))
+	mockLog := types.Log{
+		Address: common.HexToAddress("0x0"),
+		Topics: []common.Hash{
+			common.HexToHash("0x0"),
+			hash,
+		},
+		Data:        hexutil.MustDecode(hexData),
+		BlockNumber: uint64(26),
+		TxHash:      common.HexToHash("0x0"),
+		TxIndex:     111,
+		BlockHash:   common.BytesToHash([]byte{1, 2, 3, 4, 5}),
+		Index:       7,
+		Removed:     false,
+	}
+
+	abiString := `[{"anonymous":false,"inputs":[{"indexed":true,"name":"name","type":"string"},{"indexed":false,"name":"sender","type":"address"},{"indexed":false,"name":"amount","type":"uint256"},{"indexed":false,"name":"memo","type":"bytes"}],"name":"received","type":"event"}]`
+	parsedAbi, _ := abi.JSON(strings.NewReader(abiString))
+	bc := bind.NewBoundContract(common.HexToAddress("0x0"), parsedAbi, nil, nil, nil)
+
+	receivedMap := make(map[string]interface{})
+	expectedReceivedMap := map[string]interface{}{
+		"name":   hash,
+		"sender": common.HexToAddress("0x376c47978271565f56DEB45495afa69E59c16Ab2"),
+		"amount": big.NewInt(1),
+		"memo":   []byte{88},
+	}
+	if err := bc.UnpackLogIntoMap(receivedMap, "received", mockLog); err != nil {
+		t.Error(err)
+	}
+
+	if len(receivedMap) != 4 {
+		t.Fatal("unpacked map expected to have length 4")
+	}
+	if receivedMap["name"] != expectedReceivedMap["name"] {
+		t.Error("unpacked map does not match expected map")
+	}
+	if receivedMap["sender"] != expectedReceivedMap["sender"] {
+		t.Error("unpacked map does not match expected map")
+	}
+	if receivedMap["amount"].(*big.Int).Cmp(expectedReceivedMap["amount"].(*big.Int)) != 0 {
+		t.Error("unpacked map does not match expected map")
+	}
+	if !bytes.Equal(receivedMap["memo"].([]byte), expectedReceivedMap["memo"].([]byte)) {
+		t.Error("unpacked map does not match expected map")
+	}
+}
+
+func TestUnpackIndexedSliceTyLogIntoMap(t *testing.T) {
+	sliceBytes, err := rlp.EncodeToBytes([]string{"name1", "name2", "name3", "name4"})
+	if err != nil {
+		t.Fatal(err)
+	}
+	hash := crypto.Keccak256Hash(sliceBytes)
+	mockLog := types.Log{
+		Address: common.HexToAddress("0x0"),
+		Topics: []common.Hash{
+			common.HexToHash("0x0"),
+			hash,
+		},
+		Data:        hexutil.MustDecode(hexData),
+		BlockNumber: uint64(26),
+		TxHash:      common.HexToHash("0x0"),
+		TxIndex:     111,
+		BlockHash:   common.BytesToHash([]byte{1, 2, 3, 4, 5}),
+		Index:       7,
+		Removed:     false,
+	}
+
+	abiString := `[{"anonymous":false,"inputs":[{"indexed":true,"name":"names","type":"string[]"},{"indexed":false,"name":"sender","type":"address"},{"indexed":false,"name":"amount","type":"uint256"},{"indexed":false,"name":"memo","type":"bytes"}],"name":"received","type":"event"}]`
+	parsedAbi, _ := abi.JSON(strings.NewReader(abiString))
+	bc := bind.NewBoundContract(common.HexToAddress("0x0"), parsedAbi, nil, nil, nil)
+
+	receivedMap := make(map[string]interface{})
+	expectedReceivedMap := map[string]interface{}{
+		"names":  hash,
+		"sender": common.HexToAddress("0x376c47978271565f56DEB45495afa69E59c16Ab2"),
+		"amount": big.NewInt(1),
+		"memo":   []byte{88},
+	}
+	if err := bc.UnpackLogIntoMap(receivedMap, "received", mockLog); err != nil {
+		t.Error(err)
+	}
+
+	if len(receivedMap) != 4 {
+		t.Fatal("unpacked map expected to have length 4")
+	}
+	if receivedMap["names"] != expectedReceivedMap["names"] {
+		t.Error("unpacked map does not match expected map")
+	}
+	if receivedMap["sender"] != expectedReceivedMap["sender"] {
+		t.Error("unpacked map does not match expected map")
+	}
+	if receivedMap["amount"].(*big.Int).Cmp(expectedReceivedMap["amount"].(*big.Int)) != 0 {
+		t.Error("unpacked map does not match expected map")
+	}
+	if !bytes.Equal(receivedMap["memo"].([]byte), expectedReceivedMap["memo"].([]byte)) {
+		t.Error("unpacked map does not match expected map")
+	}
+}
+
+func TestUnpackIndexedArrayTyLogIntoMap(t *testing.T) {
+	arrBytes, err := rlp.EncodeToBytes([2]common.Address{common.HexToAddress("0x0"), common.HexToAddress("0x376c47978271565f56DEB45495afa69E59c16Ab2")})
+	if err != nil {
+		t.Fatal(err)
+	}
+	hash := crypto.Keccak256Hash(arrBytes)
+	mockLog := types.Log{
+		Address: common.HexToAddress("0x0"),
+		Topics: []common.Hash{
+			common.HexToHash("0x0"),
+			hash,
+		},
+		Data:        hexutil.MustDecode(hexData),
+		BlockNumber: uint64(26),
+		TxHash:      common.HexToHash("0x0"),
+		TxIndex:     111,
+		BlockHash:   common.BytesToHash([]byte{1, 2, 3, 4, 5}),
+		Index:       7,
+		Removed:     false,
+	}
+
+	abiString := `[{"anonymous":false,"inputs":[{"indexed":true,"name":"addresses","type":"address[2]"},{"indexed":false,"name":"sender","type":"address"},{"indexed":false,"name":"amount","type":"uint256"},{"indexed":false,"name":"memo","type":"bytes"}],"name":"received","type":"event"}]`
+	parsedAbi, _ := abi.JSON(strings.NewReader(abiString))
+	bc := bind.NewBoundContract(common.HexToAddress("0x0"), parsedAbi, nil, nil, nil)
+
+	receivedMap := make(map[string]interface{})
+	expectedReceivedMap := map[string]interface{}{
+		"addresses": hash,
+		"sender":    common.HexToAddress("0x376c47978271565f56DEB45495afa69E59c16Ab2"),
+		"amount":    big.NewInt(1),
+		"memo":      []byte{88},
+	}
+	if err := bc.UnpackLogIntoMap(receivedMap, "received", mockLog); err != nil {
+		t.Error(err)
+	}
+
+	if len(receivedMap) != 4 {
+		t.Fatal("unpacked map expected to have length 4")
+	}
+	if receivedMap["addresses"] != expectedReceivedMap["addresses"] {
+		t.Error("unpacked map does not match expected map")
+	}
+	if receivedMap["sender"] != expectedReceivedMap["sender"] {
+		t.Error("unpacked map does not match expected map")
+	}
+	if receivedMap["amount"].(*big.Int).Cmp(expectedReceivedMap["amount"].(*big.Int)) != 0 {
+		t.Error("unpacked map does not match expected map")
+	}
+	if !bytes.Equal(receivedMap["memo"].([]byte), expectedReceivedMap["memo"].([]byte)) {
+		t.Error("unpacked map does not match expected map")
+	}
+}
+
+func TestUnpackIndexedFuncTyLogIntoMap(t *testing.T) {
+	mockAddress := common.HexToAddress("0x376c47978271565f56DEB45495afa69E59c16Ab2")
+	addrBytes := mockAddress.Bytes()
+	hash := crypto.Keccak256Hash([]byte("mockFunction(address,uint)"))
+	functionSelector := hash[:4]
+	functionTyBytes := append(addrBytes, functionSelector...)
+	var functionTy [24]byte
+	copy(functionTy[:], functionTyBytes[0:24])
+	mockLog := types.Log{
+		Address: common.HexToAddress("0x0"),
+		Topics: []common.Hash{
+			common.HexToHash("0x99b5620489b6ef926d4518936cfec15d305452712b88bd59da2d9c10fb0953e8"),
+			common.BytesToHash(functionTyBytes),
+		},
+		Data:        hexutil.MustDecode(hexData),
+		BlockNumber: uint64(26),
+		TxHash:      common.HexToHash("0x5c698f13940a2153440c6d19660878bc90219d9298fdcf37365aa8d88d40fc42"),
+		TxIndex:     111,
+		BlockHash:   common.BytesToHash([]byte{1, 2, 3, 4, 5}),
+		Index:       7,
+		Removed:     false,
+	}
+
+	abiString := `[{"anonymous":false,"inputs":[{"indexed":true,"name":"function","type":"function"},{"indexed":false,"name":"sender","type":"address"},{"indexed":false,"name":"amount","type":"uint256"},{"indexed":false,"name":"memo","type":"bytes"}],"name":"received","type":"event"}]`
+	parsedAbi, _ := abi.JSON(strings.NewReader(abiString))
+	bc := bind.NewBoundContract(common.HexToAddress("0x0"), parsedAbi, nil, nil, nil)
+
+	receivedMap := make(map[string]interface{})
+	expectedReceivedMap := map[string]interface{}{
+		"function": functionTy,
+		"sender":   common.HexToAddress("0x376c47978271565f56DEB45495afa69E59c16Ab2"),
+		"amount":   big.NewInt(1),
+		"memo":     []byte{88},
+	}
+	if err := bc.UnpackLogIntoMap(receivedMap, "received", mockLog); err != nil {
+		t.Error(err)
+	}
+
+	if len(receivedMap) != 4 {
+		t.Fatal("unpacked map expected to have length 4")
+	}
+	if receivedMap["function"] != expectedReceivedMap["function"] {
+		t.Error("unpacked map does not match expected map")
+	}
+	if receivedMap["sender"] != expectedReceivedMap["sender"] {
+		t.Error("unpacked map does not match expected map")
+	}
+	if receivedMap["amount"].(*big.Int).Cmp(expectedReceivedMap["amount"].(*big.Int)) != 0 {
+		t.Error("unpacked map does not match expected map")
+	}
+	if !bytes.Equal(receivedMap["memo"].([]byte), expectedReceivedMap["memo"].([]byte)) {
+		t.Error("unpacked map does not match expected map")
+	}
+}
+
+func TestUnpackIndexedBytesTyLogIntoMap(t *testing.T) {
+	byts := []byte{1, 2, 3, 4, 5}
+	hash := crypto.Keccak256Hash(byts)
+	mockLog := types.Log{
+		Address: common.HexToAddress("0x0"),
+		Topics: []common.Hash{
+			common.HexToHash("0x99b5620489b6ef926d4518936cfec15d305452712b88bd59da2d9c10fb0953e8"),
+			hash,
+		},
+		Data:        hexutil.MustDecode(hexData),
+		BlockNumber: uint64(26),
+		TxHash:      common.HexToHash("0x5c698f13940a2153440c6d19660878bc90219d9298fdcf37365aa8d88d40fc42"),
+		TxIndex:     111,
+		BlockHash:   common.BytesToHash([]byte{1, 2, 3, 4, 5}),
+		Index:       7,
+		Removed:     false,
+	}
+
+	abiString := `[{"anonymous":false,"inputs":[{"indexed":true,"name":"content","type":"bytes"},{"indexed":false,"name":"sender","type":"address"},{"indexed":false,"name":"amount","type":"uint256"},{"indexed":false,"name":"memo","type":"bytes"}],"name":"received","type":"event"}]`
+	parsedAbi, _ := abi.JSON(strings.NewReader(abiString))
+	bc := bind.NewBoundContract(common.HexToAddress("0x0"), parsedAbi, nil, nil, nil)
+
+	receivedMap := make(map[string]interface{})
+	expectedReceivedMap := map[string]interface{}{
+		"content": hash,
+		"sender":  common.HexToAddress("0x376c47978271565f56DEB45495afa69E59c16Ab2"),
+		"amount":  big.NewInt(1),
+		"memo":    []byte{88},
+	}
+	if err := bc.UnpackLogIntoMap(receivedMap, "received", mockLog); err != nil {
+		t.Error(err)
+	}
+
+	if len(receivedMap) != 4 {
+		t.Fatal("unpacked map expected to have length 4")
+	}
+	if receivedMap["content"] != expectedReceivedMap["content"] {
+		t.Error("unpacked map does not match expected map")
+	}
+	if receivedMap["sender"] != expectedReceivedMap["sender"] {
+		t.Error("unpacked map does not match expected map")
+	}
+	if receivedMap["amount"].(*big.Int).Cmp(expectedReceivedMap["amount"].(*big.Int)) != 0 {
+		t.Error("unpacked map does not match expected map")
+	}
+	if !bytes.Equal(receivedMap["memo"].([]byte), expectedReceivedMap["memo"].([]byte)) {
+		t.Error("unpacked map does not match expected map")
+	}
+}
+
+func TestUnpackIntoMapNamingConflict(t *testing.T) {
+	hash := crypto.Keccak256Hash([]byte("testName"))
+	mockLog := types.Log{
+		Address: common.HexToAddress("0x0"),
+		Topics: []common.Hash{
+			common.HexToHash("0x0"),
+			hash,
+		},
+		Data:        hexutil.MustDecode(hexData),
+		BlockNumber: uint64(26),
+		TxHash:      common.HexToHash("0x0"),
+		TxIndex:     111,
+		BlockHash:   common.BytesToHash([]byte{1, 2, 3, 4, 5}),
+		Index:       7,
+		Removed:     false,
+	}
+
+	abiString := `[{"anonymous":false,"inputs":[{"indexed":true,"name":"name","type":"string"},{"indexed":false,"name":"sender","type":"address"},{"indexed":false,"name":"amount","type":"uint256"},{"indexed":false,"name":"memo","type":"bytes"}],"name":"received","type":"event"},{"anonymous":false,"inputs":[{"indexed":false,"name":"sender","type":"address"}],"name":"received","type":"event"}]`
+	parsedAbi, _ := abi.JSON(strings.NewReader(abiString))
+	bc := bind.NewBoundContract(common.HexToAddress("0x0"), parsedAbi, nil, nil, nil)
+	receivedMap := make(map[string]interface{})
+	if err := bc.UnpackLogIntoMap(receivedMap, "received", mockLog); err == nil {
+		t.Error("naming conflict between two events; error expected")
+	}
+}

accounts/abi/bind/bind.go

@@ -0,0 +1,424 @@
+// Copyright 2016 The go-ethereum Authors
+// This file is part of the go-ethereum library.
+//
+// The go-ethereum library is free software: you can redistribute it and/or modify
+// it under the terms of the GNU Lesser General Public License as published by
+// the Free Software Foundation, either version 3 of the License, or
+// (at your option) any later version.
+//
+// The go-ethereum library is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+// GNU Lesser General Public License for more details.
+//
+// You should have received a copy of the GNU Lesser General Public License
+// along with the go-ethereum library. If not, see <http://www.gnu.org/licenses/>.
+
+// Package bind generates Ethereum contract Go bindings.
+//
+// Detailed usage document and tutorial available on the go-ethereum Wiki page:
+// https://github.com/ethereum/go-ethereum/wiki/Native-DApps:-Go-bindings-to-Ethereum-contracts
+package bind
+
+import (
+	"bytes"
+	"fmt"
+	"go/format"
+	"regexp"
+	"strings"
+	"text/template"
+	"unicode"
+
+	"github.com/ethereum/go-ethereum/accounts/abi"
+)
+
+// Lang is a target programming language selector to generate bindings for.
+type Lang int
+
+const (
+	LangGo Lang = iota
+	LangJava
+	LangObjC
+)
+
+// Bind generates a Go wrapper around a contract ABI. This wrapper isn't meant
+// to be used as is in client code, but rather as an intermediate struct which
+// enforces compile time type safety and naming convention opposed to having to
+// manually maintain hard coded strings that break on runtime.
+func Bind(types []string, abis []string, bytecodes []string, pkg string, lang Lang) (string, error) {
+	// Process each individual contract requested binding
+	contracts := make(map[string]*tmplContract)
+
+	for i := 0; i < len(types); i++ {
+		// Parse the actual ABI to generate the binding for
+		evmABI, err := abi.JSON(strings.NewReader(abis[i]))
+		if err != nil {
+			return "", err
+		}
+		// Strip any whitespace from the JSON ABI
+		strippedABI := strings.Map(func(r rune) rune {
+			if unicode.IsSpace(r) {
+				return -1
+			}
+			return r
+		}, abis[i])
+
+		// Extract the call and transact methods; events; and sort them alphabetically
+		var (
+			calls     = make(map[string]*tmplMethod)
+			transacts = make(map[string]*tmplMethod)
+			events    = make(map[string]*tmplEvent)
+		)
+		for _, original := range evmABI.Methods {
+			// Normalize the method for capital cases and non-anonymous inputs/outputs
+			normalized := original
+			normalized.Name = methodNormalizer[lang](original.Name)
+
+			normalized.Inputs = make([]abi.Argument, len(original.Inputs))
+			copy(normalized.Inputs, original.Inputs)
+			for j, input := range normalized.Inputs {
+				if input.Name == "" {
+					normalized.Inputs[j].Name = fmt.Sprintf("arg%d", j)
+				}
+			}
+			normalized.Outputs = make([]abi.Argument, len(original.Outputs))
+			copy(normalized.Outputs, original.Outputs)
+			for j, output := range normalized.Outputs {
+				if output.Name != "" {
+					normalized.Outputs[j].Name = capitalise(output.Name)
+				}
+			}
+			// Append the methods to the call or transact lists
+			if original.Const {
+				calls[original.Name] = &tmplMethod{Original: original, Normalized: normalized, Structured: structured(original.Outputs)}
+			} else {
+				transacts[original.Name] = &tmplMethod{Original: original, Normalized: normalized, Structured: structured(original.Outputs)}
+			}
+		}
+		for _, original := range evmABI.Events {
+			// Skip anonymous events as they don't support explicit filtering
+			if original.Anonymous {
+				continue
+			}
+			// Normalize the event for capital cases and non-anonymous outputs
+			normalized := original
+			normalized.Name = methodNormalizer[lang](original.Name)
+
+			normalized.Inputs = make([]abi.Argument, len(original.Inputs))
+			copy(normalized.Inputs, original.Inputs)
+			for j, input := range normalized.Inputs {
+				// Indexed fields are input, non-indexed ones are outputs
+				if input.Indexed {
+					if input.Name == "" {
+						normalized.Inputs[j].Name = fmt.Sprintf("arg%d", j)
+					}
+				}
+			}
+			// Append the event to the accumulator list
+			events[original.Name] = &tmplEvent{Original: original, Normalized: normalized}
+		}
+		contracts[types[i]] = &tmplContract{
+			Type:        capitalise(types[i]),
+			InputABI:    strings.Replace(strippedABI, "\"", "\\\"", -1),
+			InputBin:    strings.TrimSpace(bytecodes[i]),
+			Constructor: evmABI.Constructor,
+			Calls:       calls,
+			Transacts:   transacts,
+			Events:      events,
+		}
+	}
+	// Generate the contract template data content and render it
+	data := &tmplData{
+		Package:   pkg,
+		Contracts: contracts,
+	}
+	buffer := new(bytes.Buffer)
+
+	funcs := map[string]interface{}{
+		"bindtype":      bindType[lang],
+		"bindtopictype": bindTopicType[lang],
+		"namedtype":     namedType[lang],
+		"capitalise":    capitalise,
+		"decapitalise":  decapitalise,
+	}
+	tmpl := template.Must(template.New("").Funcs(funcs).Parse(tmplSource[lang]))
+	if err := tmpl.Execute(buffer, data); err != nil {
+		return "", err
+	}
+	// For Go bindings pass the code through gofmt to clean it up
+	if lang == LangGo {
+		code, err := format.Source(buffer.Bytes())
+		if err != nil {
+			return "", fmt.Errorf("%v\n%s", err, buffer)
+		}
+		return string(code), nil
+	}
+	// For all others just return as is for now
+	return buffer.String(), nil
+}
+
+// bindType is a set of type binders that convert Solidity types to some supported
+// programming language types.
+var bindType = map[Lang]func(kind abi.Type) string{
+	LangGo:   bindTypeGo,
+	LangJava: bindTypeJava,
+}
+
+// Helper function for the binding generators.
+// It reads the unmatched characters after the inner type-match,
+//  (since the inner type is a prefix of the total type declaration),
+//  looks for valid arrays (possibly a dynamic one) wrapping the inner type,
+//  and returns the sizes of these arrays.
+//
+// Returned array sizes are in the same order as solidity signatures; inner array size first.
+// Array sizes may also be "", indicating a dynamic array.
+func wrapArray(stringKind string, innerLen int, innerMapping string) (string, []string) {
+	remainder := stringKind[innerLen:]
+	//find all the sizes
+	matches := regexp.MustCompile(`\[(\d*)\]`).FindAllStringSubmatch(remainder, -1)
+	parts := make([]string, 0, len(matches))
+	for _, match := range matches {
+		//get group 1 from the regex match
+		parts = append(parts, match[1])
+	}
+	return innerMapping, parts
+}
+
+// Translates the array sizes to a Go-lang declaration of a (nested) array of the inner type.
+// Simply returns the inner type if arraySizes is empty.
+func arrayBindingGo(inner string, arraySizes []string) string {
+	out := ""
+	//prepend all array sizes, from outer (end arraySizes) to inner (start arraySizes)
+	for i := len(arraySizes) - 1; i >= 0; i-- {
+		out += "[" + arraySizes[i] + "]"
+	}
+	out += inner
+	return out
+}
+
+// bindTypeGo converts a Solidity type to a Go one. Since there is no clear mapping
+// from all Solidity types to Go ones (e.g. uint17), those that cannot be exactly
+// mapped will use an upscaled type (e.g. *big.Int).
+func bindTypeGo(kind abi.Type) string {
+	stringKind := kind.String()
+	innerLen, innerMapping := bindUnnestedTypeGo(stringKind)
+	return arrayBindingGo(wrapArray(stringKind, innerLen, innerMapping))
+}
+
+// The inner function of bindTypeGo, this finds the inner type of stringKind.
+// (Or just the type itself if it is not an array or slice)
+// The length of the matched part is returned, with the translated type.
+func bindUnnestedTypeGo(stringKind string) (int, string) {
+
+	switch {
+	case strings.HasPrefix(stringKind, "address"):
+		return len("address"), "common.Address"
+
+	case strings.HasPrefix(stringKind, "bytes"):
+		parts := regexp.MustCompile(`bytes([0-9]*)`).FindStringSubmatch(stringKind)
+		return len(parts[0]), fmt.Sprintf("[%s]byte", parts[1])
+
+	case strings.HasPrefix(stringKind, "int") || strings.HasPrefix(stringKind, "uint"):
+		parts := regexp.MustCompile(`(u)?int([0-9]*)`).FindStringSubmatch(stringKind)
+		switch parts[2] {
+		case "8", "16", "32", "64":
+			return len(parts[0]), fmt.Sprintf("%sint%s", parts[1], parts[2])
+		}
+		return len(parts[0]), "*big.Int"
+
+	case strings.HasPrefix(stringKind, "bool"):
+		return len("bool"), "bool"
+
+	case strings.HasPrefix(stringKind, "string"):
+		return len("string"), "string"
+
+	default:
+		return len(stringKind), stringKind
+	}
+}
+
+// Translates the array sizes to a Java declaration of a (nested) array of the inner type.
+// Simply returns the inner type if arraySizes is empty.
+func arrayBindingJava(inner string, arraySizes []string) string {
+	// Java array type declarations do not include the length.
+	return inner + strings.Repeat("[]", len(arraySizes))
+}
+
+// bindTypeJava converts a Solidity type to a Java one. Since there is no clear mapping
+// from all Solidity types to Java ones (e.g. uint17), those that cannot be exactly
+// mapped will use an upscaled type (e.g. BigDecimal).
+func bindTypeJava(kind abi.Type) string {
+	stringKind := kind.String()
+	innerLen, innerMapping := bindUnnestedTypeJava(stringKind)
+	return arrayBindingJava(wrapArray(stringKind, innerLen, innerMapping))
+}
+
+// The inner function of bindTypeJava, this finds the inner type of stringKind.
+// (Or just the type itself if it is not an array or slice)
+// The length of the matched part is returned, with the translated type.
+func bindUnnestedTypeJava(stringKind string) (int, string) {
+
+	switch {
+	case strings.HasPrefix(stringKind, "address"):
+		parts := regexp.MustCompile(`address(\[[0-9]*\])?`).FindStringSubmatch(stringKind)
+		if len(parts) != 2 {
+			return len(stringKind), stringKind
+		}
+		if parts[1] == "" {
+			return len("address"), "Address"
+		}
+		return len(parts[0]), "Addresses"
+
+	case strings.HasPrefix(stringKind, "bytes"):
+		parts := regexp.MustCompile(`bytes([0-9]*)`).FindStringSubmatch(stringKind)
+		if len(parts) != 2 {
+			return len(stringKind), stringKind
+		}
+		return len(parts[0]), "byte[]"
+
+	case strings.HasPrefix(stringKind, "int") || strings.HasPrefix(stringKind, "uint"):
+		//Note that uint and int (without digits) are also matched,
+		// these are size 256, and will translate to BigInt (the default).
+		parts := regexp.MustCompile(`(u)?int([0-9]*)`).FindStringSubmatch(stringKind)
+		if len(parts) != 3 {
+			return len(stringKind), stringKind
+		}
+
+		namedSize := map[string]string{
+			"8":  "byte",
+			"16": "short",
+			"32": "int",
+			"64": "long",
+		}[parts[2]]
+
+		//default to BigInt
+		if namedSize == "" {
+			namedSize = "BigInt"
+		}
+		return len(parts[0]), namedSize
+
+	case strings.HasPrefix(stringKind, "bool"):
+		return len("bool"), "boolean"
+
+	case strings.HasPrefix(stringKind, "string"):
+		return len("string"), "String"
+
+	default:
+		return len(stringKind), stringKind
+	}
+}
+
+// bindTopicType is a set of type binders that convert Solidity types to some
+// supported programming language topic types.
+var bindTopicType = map[Lang]func(kind abi.Type) string{
+	LangGo:   bindTopicTypeGo,
+	LangJava: bindTopicTypeJava,
+}
+
+// bindTypeGo converts a Solidity topic type to a Go one. It is almost the same
+// funcionality as for simple types, but dynamic types get converted to hashes.
+func bindTopicTypeGo(kind abi.Type) string {
+	bound := bindTypeGo(kind)
+	if bound == "string" || bound == "[]byte" {
+		bound = "common.Hash"
+	}
+	return bound
+}
+
+// bindTypeGo converts a Solidity topic type to a Java one. It is almost the same
+// funcionality as for simple types, but dynamic types get converted to hashes.
+func bindTopicTypeJava(kind abi.Type) string {
+	bound := bindTypeJava(kind)
+	if bound == "String" || bound == "Bytes" {
+		bound = "Hash"
+	}
+	return bound
+}
+
+// namedType is a set of functions that transform language specific types to
+// named versions that my be used inside method names.
+var namedType = map[Lang]func(string, abi.Type) string{
+	LangGo:   func(string, abi.Type) string { panic("this shouldn't be needed") },
+	LangJava: namedTypeJava,
+}
+
+// namedTypeJava converts some primitive data types to named variants that can
+// be used as parts of method names.
+func namedTypeJava(javaKind string, solKind abi.Type) string {
+	switch javaKind {
+	case "byte[]":
+		return "Binary"
+	case "byte[][]":
+		return "Binaries"
+	case "string":
+		return "String"
+	case "string[]":
+		return "Strings"
+	case "boolean":
+		return "Bool"
+	case "boolean[]":
+		return "Bools"
+	case "BigInt[]":
+		return "BigInts"
+	default:
+		parts := regexp.MustCompile(`(u)?int([0-9]*)(\[[0-9]*\])?`).FindStringSubmatch(solKind.String())
+		if len(parts) != 4 {
+			return javaKind
+		}
+		switch parts[2] {
+		case "8", "16", "32", "64":
+			if parts[3] == "" {
+				return capitalise(fmt.Sprintf("%sint%s", parts[1], parts[2]))
+			}
+			return capitalise(fmt.Sprintf("%sint%ss", parts[1], parts[2]))
+
+		default:
+			return javaKind
+		}
+	}
+}
+
+// methodNormalizer is a name transformer that modifies Solidity method names to
+// conform to target language naming concentions.
+var methodNormalizer = map[Lang]func(string) string{
+	LangGo:   abi.ToCamelCase,
+	LangJava: decapitalise,
+}
+
+// capitalise makes a camel-case string which starts with an upper case character.
+func capitalise(input string) string {
+	return abi.ToCamelCase(input)
+}
+
+// decapitalise makes a camel-case string which starts with a lower case character.
+func decapitalise(input string) string {
+	if len(input) == 0 {
+		return input
+	}
+
+	goForm := abi.ToCamelCase(input)
+	return strings.ToLower(goForm[:1]) + goForm[1:]
+}
+
+// structured checks whether a list of ABI data types has enough information to
+// operate through a proper Go struct or if flat returns are needed.
+func structured(args abi.Arguments) bool {
+	if len(args) < 2 {
+		return false
+	}
+	exists := make(map[string]bool)
+	for _, out := range args {
+		// If the name is anonymous, we can't organize into a struct
+		if out.Name == "" {
+			return false
+		}
+		// If the field name is empty when normalized or collides (var, Var, _var, _Var),
+		// we can't organize into a struct
+		field := capitalise(out.Name)
+		if field == "" || exists[field] {
+			return false
+		}
+		exists[field] = true
+	}
+	return true
+}

accounts/abi/bind/template.go

@@ -0,0 +1,546 @@
+// Copyright 2016 The go-ethereum Authors
+// This file is part of the go-ethereum library.
+//
+// The go-ethereum library is free software: you can redistribute it and/or modify
+// it under the terms of the GNU Lesser General Public License as published by
+// the Free Software Foundation, either version 3 of the License, or
+// (at your option) any later version.
+//
+// The go-ethereum library is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+// GNU Lesser General Public License for more details.
+//
+// You should have received a copy of the GNU Lesser General Public License
+// along with the go-ethereum library. If not, see <http://www.gnu.org/licenses/>.
+
+package bind
+
+import "github.com/ethereum/go-ethereum/accounts/abi"
+
+// tmplData is the data structure required to fill the binding template.
+type tmplData struct {
+	Package   string                   // Name of the package to place the generated file in
+	Contracts map[string]*tmplContract // List of contracts to generate into this file
+}
+
+// tmplContract contains the data needed to generate an individual contract binding.
+type tmplContract struct {
+	Type        string                 // Type name of the main contract binding
+	InputABI    string                 // JSON ABI used as the input to generate the binding from
+	InputBin    string                 // Optional EVM bytecode used to denetare deploy code from
+	Constructor abi.Method             // Contract constructor for deploy parametrization
+	Calls       map[string]*tmplMethod // Contract calls that only read state data
+	Transacts   map[string]*tmplMethod // Contract calls that write state data
+	Events      map[string]*tmplEvent  // Contract events accessors
+}
+
+// tmplMethod is a wrapper around an abi.Method that contains a few preprocessed
+// and cached data fields.
+type tmplMethod struct {
+	Original   abi.Method // Original method as parsed by the abi package
+	Normalized abi.Method // Normalized version of the parsed method (capitalized names, non-anonymous args/returns)
+	Structured bool       // Whether the returns should be accumulated into a struct
+}
+
+// tmplEvent is a wrapper around an a
+type tmplEvent struct {
+	Original   abi.Event // Original event as parsed by the abi package
+	Normalized abi.Event // Normalized version of the parsed fields
+}
+
+// tmplSource is language to template mapping containing all the supported
+// programming languages the package can generate to.
+var tmplSource = map[Lang]string{
+	LangGo:   tmplSourceGo,
+	LangJava: tmplSourceJava,
+}
+
+// tmplSourceGo is the Go source template use to generate the contract binding
+// based on.
+const tmplSourceGo = `
+// Code generated - DO NOT EDIT.
+// This file is a generated binding and any manual changes will be lost.
+
+package {{.Package}}
+
+import (
+	"math/big"
+	"strings"
+
+	ethereum "github.com/ethereum/go-ethereum"
+	"github.com/ethereum/go-ethereum/accounts/abi"
+	"github.com/ethereum/go-ethereum/accounts/abi/bind"
+	"github.com/ethereum/go-ethereum/common"
+	"github.com/ethereum/go-ethereum/core/types"
+	"github.com/ethereum/go-ethereum/event"
+)
+
+// Reference imports to suppress errors if they are not otherwise used.
+var (
+	_ = big.NewInt
+	_ = strings.NewReader
+	_ = ethereum.NotFound
+	_ = abi.U256
+	_ = bind.Bind
+	_ = common.Big1
+	_ = types.BloomLookup
+	_ = event.NewSubscription
+)
+
+{{range $contract := .Contracts}}
+	// {{.Type}}ABI is the input ABI used to generate the binding from.
+	const {{.Type}}ABI = "{{.InputABI}}"
+
+	{{if .InputBin}}
+		// {{.Type}}Bin is the compiled bytecode used for deploying new contracts.
+		const {{.Type}}Bin = ` + "`" + `{{.InputBin}}` + "`" + `
+
+		// Deploy{{.Type}} deploys a new Ethereum contract, binding an instance of {{.Type}} to it.
+		func Deploy{{.Type}}(auth *bind.TransactOpts, backend bind.ContractBackend {{range .Constructor.Inputs}}, {{.Name}} {{bindtype .Type}}{{end}}) (common.Address, *types.Transaction, *{{.Type}}, error) {
+		  parsed, err := abi.JSON(strings.NewReader({{.Type}}ABI))
+		  if err != nil {
+		    return common.Address{}, nil, nil, err
+		  }
+		  address, tx, contract, err := bind.DeployContract(auth, parsed, common.FromHex({{.Type}}Bin), backend {{range .Constructor.Inputs}}, {{.Name}}{{end}})
+		  if err != nil {
+		    return common.Address{}, nil, nil, err
+		  }
+		  return address, tx, &{{.Type}}{ {{.Type}}Caller: {{.Type}}Caller{contract: contract}, {{.Type}}Transactor: {{.Type}}Transactor{contract: contract}, {{.Type}}Filterer: {{.Type}}Filterer{contract: contract} }, nil
+		}
+	{{end}}
+
+	// {{.Type}} is an auto generated Go binding around an Ethereum contract.
+	type {{.Type}} struct {
+	  {{.Type}}Caller     // Read-only binding to the contract
+	  {{.Type}}Transactor // Write-only binding to the contract
+		{{.Type}}Filterer   // Log filterer for contract events
+	}
+
+	// {{.Type}}Caller is an auto generated read-only Go binding around an Ethereum contract.
+	type {{.Type}}Caller struct {
+	  contract *bind.BoundContract // Generic contract wrapper for the low level calls
+	}
+
+	// {{.Type}}Transactor is an auto generated write-only Go binding around an Ethereum contract.
+	type {{.Type}}Transactor struct {
+	  contract *bind.BoundContract // Generic contract wrapper for the low level calls
+	}
+
+	// {{.Type}}Filterer is an auto generated log filtering Go binding around an Ethereum contract events.
+	type {{.Type}}Filterer struct {
+	  contract *bind.BoundContract // Generic contract wrapper for the low level calls
+	}
+
+	// {{.Type}}Session is an auto generated Go binding around an Ethereum contract,
+	// with pre-set call and transact options.
+	type {{.Type}}Session struct {
+	  Contract     *{{.Type}}        // Generic contract binding to set the session for
+	  CallOpts     bind.CallOpts     // Call options to use throughout this session
+	  TransactOpts bind.TransactOpts // Transaction auth options to use throughout this session
+	}
+
+	// {{.Type}}CallerSession is an auto generated read-only Go binding around an Ethereum contract,
+	// with pre-set call options.
+	type {{.Type}}CallerSession struct {
+	  Contract *{{.Type}}Caller // Generic contract caller binding to set the session for
+	  CallOpts bind.CallOpts    // Call options to use throughout this session
+	}
+
+	// {{.Type}}TransactorSession is an auto generated write-only Go binding around an Ethereum contract,
+	// with pre-set transact options.
+	type {{.Type}}TransactorSession struct {
+	  Contract     *{{.Type}}Transactor // Generic contract transactor binding to set the session for
+	  TransactOpts bind.TransactOpts    // Transaction auth options to use throughout this session
+	}
+
+	// {{.Type}}Raw is an auto generated low-level Go binding around an Ethereum contract.
+	type {{.Type}}Raw struct {
+	  Contract *{{.Type}} // Generic contract binding to access the raw methods on
+	}
+
+	// {{.Type}}CallerRaw is an auto generated low-level read-only Go binding around an Ethereum contract.
+	type {{.Type}}CallerRaw struct {
+		Contract *{{.Type}}Caller // Generic read-only contract binding to access the raw methods on
+	}
+
+	// {{.Type}}TransactorRaw is an auto generated low-level write-only Go binding around an Ethereum contract.
+	type {{.Type}}TransactorRaw struct {
+		Contract *{{.Type}}Transactor // Generic write-only contract binding to access the raw methods on
+	}
+
+	// New{{.Type}} creates a new instance of {{.Type}}, bound to a specific deployed contract.
+	func New{{.Type}}(address common.Address, backend bind.ContractBackend) (*{{.Type}}, error) {
+	  contract, err := bind{{.Type}}(address, backend, backend, backend)
+	  if err != nil {
+	    return nil, err
+	  }
+	  return &{{.Type}}{ {{.Type}}Caller: {{.Type}}Caller{contract: contract}, {{.Type}}Transactor: {{.Type}}Transactor{contract: contract}, {{.Type}}Filterer: {{.Type}}Filterer{contract: contract} }, nil
+	}
+
+	// New{{.Type}}Caller creates a new read-only instance of {{.Type}}, bound to a specific deployed contract.
+	func New{{.Type}}Caller(address common.Address, caller bind.ContractCaller) (*{{.Type}}Caller, error) {
+	  contract, err := bind{{.Type}}(address, caller, nil, nil)
+	  if err != nil {
+	    return nil, err
+	  }
+	  return &{{.Type}}Caller{contract: contract}, nil
+	}
+
+	// New{{.Type}}Transactor creates a new write-only instance of {{.Type}}, bound to a specific deployed contract.
+	func New{{.Type}}Transactor(address common.Address, transactor bind.ContractTransactor) (*{{.Type}}Transactor, error) {
+	  contract, err := bind{{.Type}}(address, nil, transactor, nil)
+	  if err != nil {
+	    return nil, err
+	  }
+	  return &{{.Type}}Transactor{contract: contract}, nil
+	}
+
+	// New{{.Type}}Filterer creates a new log filterer instance of {{.Type}}, bound to a specific deployed contract.
+ 	func New{{.Type}}Filterer(address common.Address, filterer bind.ContractFilterer) (*{{.Type}}Filterer, error) {
+ 	  contract, err := bind{{.Type}}(address, nil, nil, filterer)
+ 	  if err != nil {
+ 	    return nil, err
+ 	  }
+ 	  return &{{.Type}}Filterer{contract: contract}, nil
+ 	}
+
+	// bind{{.Type}} binds a generic wrapper to an already deployed contract.
+	func bind{{.Type}}(address common.Address, caller bind.ContractCaller, transactor bind.ContractTransactor, filterer bind.ContractFilterer) (*bind.BoundContract, error) {
+	  parsed, err := abi.JSON(strings.NewReader({{.Type}}ABI))
+	  if err != nil {
+	    return nil, err
+	  }
+	  return bind.NewBoundContract(address, parsed, caller, transactor, filterer), nil
+	}
+
+	// Call invokes the (constant) contract method with params as input values and
+	// sets the output to result. The result type might be a single field for simple
+	// returns, a slice of interfaces for anonymous returns and a struct for named
+	// returns.
+	func (_{{$contract.Type}} *{{$contract.Type}}Raw) Call(opts *bind.CallOpts, result interface{}, method string, params ...interface{}) error {
+		return _{{$contract.Type}}.Contract.{{$contract.Type}}Caller.contract.Call(opts, result, method, params...)
+	}
+
+	// Transfer initiates a plain transaction to move funds to the contract, calling
+	// its default method if one is available.
+	func (_{{$contract.Type}} *{{$contract.Type}}Raw) Transfer(opts *bind.TransactOpts) (*types.Transaction, error) {
+		return _{{$contract.Type}}.Contract.{{$contract.Type}}Transactor.contract.Transfer(opts)
+	}
+
+	// Transact invokes the (paid) contract method with params as input values.
+	func (_{{$contract.Type}} *{{$contract.Type}}Raw) Transact(opts *bind.TransactOpts, method string, params ...interface{}) (*types.Transaction, error) {
+		return _{{$contract.Type}}.Contract.{{$contract.Type}}Transactor.contract.Transact(opts, method, params...)
+	}
+
+	// Call invokes the (constant) contract method with params as input values and
+	// sets the output to result. The result type might be a single field for simple
+	// returns, a slice of interfaces for anonymous returns and a struct for named
+	// returns.
+	func (_{{$contract.Type}} *{{$contract.Type}}CallerRaw) Call(opts *bind.CallOpts, result interface{}, method string, params ...interface{}) error {
+		return _{{$contract.Type}}.Contract.contract.Call(opts, result, method, params...)
+	}
+
+	// Transfer initiates a plain transaction to move funds to the contract, calling
+	// its default method if one is available.
+	func (_{{$contract.Type}} *{{$contract.Type}}TransactorRaw) Transfer(opts *bind.TransactOpts) (*types.Transaction, error) {
+		return _{{$contract.Type}}.Contract.contract.Transfer(opts)
+	}
+
+	// Transact invokes the (paid) contract method with params as input values.
+	func (_{{$contract.Type}} *{{$contract.Type}}TransactorRaw) Transact(opts *bind.TransactOpts, method string, params ...interface{}) (*types.Transaction, error) {
+		return _{{$contract.Type}}.Contract.contract.Transact(opts, method, params...)
+	}
+
+	{{range .Calls}}
+		// {{.Normalized.Name}} is a free data retrieval call binding the contract method 0x{{printf "%x" .Original.Id}}.
+		//
+		// Solidity: {{.Original.String}}
+		func (_{{$contract.Type}} *{{$contract.Type}}Caller) {{.Normalized.Name}}(opts *bind.CallOpts {{range .Normalized.Inputs}}, {{.Name}} {{bindtype .Type}} {{end}}) ({{if .Structured}}struct{ {{range .Normalized.Outputs}}{{.Name}} {{bindtype .Type}};{{end}} },{{else}}{{range .Normalized.Outputs}}{{bindtype .Type}},{{end}}{{end}} error) {
+			{{if .Structured}}ret := new(struct{
+				{{range .Normalized.Outputs}}{{.Name}} {{bindtype .Type}}
+				{{end}}
+			}){{else}}var (
+				{{range $i, $_ := .Normalized.Outputs}}ret{{$i}} = new({{bindtype .Type}})
+				{{end}}
+			){{end}}
+			out := {{if .Structured}}ret{{else}}{{if eq (len .Normalized.Outputs) 1}}ret0{{else}}&[]interface{}{
+				{{range $i, $_ := .Normalized.Outputs}}ret{{$i}},
+				{{end}}
+			}{{end}}{{end}}
+			err := _{{$contract.Type}}.contract.Call(opts, out, "{{.Original.Name}}" {{range .Normalized.Inputs}}, {{.Name}}{{end}})
+			return {{if .Structured}}*ret,{{else}}{{range $i, $_ := .Normalized.Outputs}}*ret{{$i}},{{end}}{{end}} err
+		}
+
+		// {{.Normalized.Name}} is a free data retrieval call binding the contract method 0x{{printf "%x" .Original.Id}}.
+		//
+		// Solidity: {{.Original.String}}
+		func (_{{$contract.Type}} *{{$contract.Type}}Session) {{.Normalized.Name}}({{range $i, $_ := .Normalized.Inputs}}{{if ne $i 0}},{{end}} {{.Name}} {{bindtype .Type}} {{end}}) ({{if .Structured}}struct{ {{range .Normalized.Outputs}}{{.Name}} {{bindtype .Type}};{{end}} }, {{else}} {{range .Normalized.Outputs}}{{bindtype .Type}},{{end}} {{end}} error) {
+		  return _{{$contract.Type}}.Contract.{{.Normalized.Name}}(&_{{$contract.Type}}.CallOpts {{range .Normalized.Inputs}}, {{.Name}}{{end}})
+		}
+
+		// {{.Normalized.Name}} is a free data retrieval call binding the contract method 0x{{printf "%x" .Original.Id}}.
+		//
+		// Solidity: {{.Original.String}}
+		func (_{{$contract.Type}} *{{$contract.Type}}CallerSession) {{.Normalized.Name}}({{range $i, $_ := .Normalized.Inputs}}{{if ne $i 0}},{{end}} {{.Name}} {{bindtype .Type}} {{end}}) ({{if .Structured}}struct{ {{range .Normalized.Outputs}}{{.Name}} {{bindtype .Type}};{{end}} }, {{else}} {{range .Normalized.Outputs}}{{bindtype .Type}},{{end}} {{end}} error) {
+		  return _{{$contract.Type}}.Contract.{{.Normalized.Name}}(&_{{$contract.Type}}.CallOpts {{range .Normalized.Inputs}}, {{.Name}}{{end}})
+		}
+	{{end}}
+
+	{{range .Transacts}}
+		// {{.Normalized.Name}} is a paid mutator transaction binding the contract method 0x{{printf "%x" .Original.Id}}.
+		//
+		// Solidity: {{.Original.String}}
+		func (_{{$contract.Type}} *{{$contract.Type}}Transactor) {{.Normalized.Name}}(opts *bind.TransactOpts {{range .Normalized.Inputs}}, {{.Name}} {{bindtype .Type}} {{end}}) (*types.Transaction, error) {
+			return _{{$contract.Type}}.contract.Transact(opts, "{{.Original.Name}}" {{range .Normalized.Inputs}}, {{.Name}}{{end}})
+		}
+
+		// {{.Normalized.Name}} is a paid mutator transaction binding the contract method 0x{{printf "%x" .Original.Id}}.
+		//
+		// Solidity: {{.Original.String}}
+		func (_{{$contract.Type}} *{{$contract.Type}}Session) {{.Normalized.Name}}({{range $i, $_ := .Normalized.Inputs}}{{if ne $i 0}},{{end}} {{.Name}} {{bindtype .Type}} {{end}}) (*types.Transaction, error) {
+		  return _{{$contract.Type}}.Contract.{{.Normalized.Name}}(&_{{$contract.Type}}.TransactOpts {{range $i, $_ := .Normalized.Inputs}}, {{.Name}}{{end}})
+		}
+
+		// {{.Normalized.Name}} is a paid mutator transaction binding the contract method 0x{{printf "%x" .Original.Id}}.
+		//
+		// Solidity: {{.Original.String}}
+		func (_{{$contract.Type}} *{{$contract.Type}}TransactorSession) {{.Normalized.Name}}({{range $i, $_ := .Normalized.Inputs}}{{if ne $i 0}},{{end}} {{.Name}} {{bindtype .Type}} {{end}}) (*types.Transaction, error) {
+		  return _{{$contract.Type}}.Contract.{{.Normalized.Name}}(&_{{$contract.Type}}.TransactOpts {{range $i, $_ := .Normalized.Inputs}}, {{.Name}}{{end}})
+		}
+	{{end}}
+
+	{{range .Events}}
+		// {{$contract.Type}}{{.Normalized.Name}}Iterator is returned from Filter{{.Normalized.Name}} and is used to iterate over the raw logs and unpacked data for {{.Normalized.Name}} events raised by the {{$contract.Type}} contract.
+		type {{$contract.Type}}{{.Normalized.Name}}Iterator struct {
+			Event *{{$contract.Type}}{{.Normalized.Name}} // Event containing the contract specifics and raw log
+
+			contract *bind.BoundContract // Generic contract to use for unpacking event data
+			event    string              // Event name to use for unpacking event data
+
+			logs chan types.Log        // Log channel receiving the found contract events
+			sub  ethereum.Subscription // Subscription for errors, completion and termination
+			done bool                  // Whether the subscription completed delivering logs
+			fail error                 // Occurred error to stop iteration
+		}
+		// Next advances the iterator to the subsequent event, returning whether there
+		// are any more events found. In case of a retrieval or parsing error, false is
+		// returned and Error() can be queried for the exact failure.
+		func (it *{{$contract.Type}}{{.Normalized.Name}}Iterator) Next() bool {
+			// If the iterator failed, stop iterating
+			if (it.fail != nil) {
+				return false
+			}
+			// If the iterator completed, deliver directly whatever's available
+			if (it.done) {
+				select {
+				case log := <-it.logs:
+					it.Event = new({{$contract.Type}}{{.Normalized.Name}})
+					if err := it.contract.UnpackLog(it.Event, it.event, log); err != nil {
+						it.fail = err
+						return false
+					}
+					it.Event.Raw = log
+					return true
+
+				default:
+					return false
+				}
+			}
+			// Iterator still in progress, wait for either a data or an error event
+			select {
+			case log := <-it.logs:
+				it.Event = new({{$contract.Type}}{{.Normalized.Name}})
+				if err := it.contract.UnpackLog(it.Event, it.event, log); err != nil {
+					it.fail = err
+					return false
+				}
+				it.Event.Raw = log
+				return true
+
+			case err := <-it.sub.Err():
+				it.done = true
+				it.fail = err
+				return it.Next()
+			}
+		}
+		// Error returns any retrieval or parsing error occurred during filtering.
+		func (it *{{$contract.Type}}{{.Normalized.Name}}Iterator) Error() error {
+			return it.fail
+		}
+		// Close terminates the iteration process, releasing any pending underlying
+		// resources.
+		func (it *{{$contract.Type}}{{.Normalized.Name}}Iterator) Close() error {
+			it.sub.Unsubscribe()
+			return nil
+		}
+
+		// {{$contract.Type}}{{.Normalized.Name}} represents a {{.Normalized.Name}} event raised by the {{$contract.Type}} contract.
+		type {{$contract.Type}}{{.Normalized.Name}} struct { {{range .Normalized.Inputs}}
+			{{capitalise .Name}} {{if .Indexed}}{{bindtopictype .Type}}{{else}}{{bindtype .Type}}{{end}}; {{end}}
+			Raw types.Log // Blockchain specific contextual infos
+		}
+
+		// Filter{{.Normalized.Name}} is a free log retrieval operation binding the contract event 0x{{printf "%x" .Original.Id}}.
+		//
+		// Solidity: {{.Original.String}}
+ 		func (_{{$contract.Type}} *{{$contract.Type}}Filterer) Filter{{.Normalized.Name}}(opts *bind.FilterOpts{{range .Normalized.Inputs}}{{if .Indexed}}, {{.Name}} []{{bindtype .Type}}{{end}}{{end}}) (*{{$contract.Type}}{{.Normalized.Name}}Iterator, error) {
+			{{range .Normalized.Inputs}}
+			{{if .Indexed}}var {{.Name}}Rule []interface{}
+			for _, {{.Name}}Item := range {{.Name}} {
+				{{.Name}}Rule = append({{.Name}}Rule, {{.Name}}Item)
+			}{{end}}{{end}}
+
+			logs, sub, err := _{{$contract.Type}}.contract.FilterLogs(opts, "{{.Original.Name}}"{{range .Normalized.Inputs}}{{if .Indexed}}, {{.Name}}Rule{{end}}{{end}})
+			if err != nil {
+				return nil, err
+			}
+			return &{{$contract.Type}}{{.Normalized.Name}}Iterator{contract: _{{$contract.Type}}.contract, event: "{{.Original.Name}}", logs: logs, sub: sub}, nil
+ 		}
+
+		// Watch{{.Normalized.Name}} is a free log subscription operation binding the contract event 0x{{printf "%x" .Original.Id}}.
+		//
+		// Solidity: {{.Original.String}}
+		func (_{{$contract.Type}} *{{$contract.Type}}Filterer) Watch{{.Normalized.Name}}(opts *bind.WatchOpts, sink chan<- *{{$contract.Type}}{{.Normalized.Name}}{{range .Normalized.Inputs}}{{if .Indexed}}, {{.Name}} []{{bindtype .Type}}{{end}}{{end}}) (event.Subscription, error) {
+			{{range .Normalized.Inputs}}
+			{{if .Indexed}}var {{.Name}}Rule []interface{}
+			for _, {{.Name}}Item := range {{.Name}} {
+				{{.Name}}Rule = append({{.Name}}Rule, {{.Name}}Item)
+			}{{end}}{{end}}
+
+			logs, sub, err := _{{$contract.Type}}.contract.WatchLogs(opts, "{{.Original.Name}}"{{range .Normalized.Inputs}}{{if .Indexed}}, {{.Name}}Rule{{end}}{{end}})
+			if err != nil {
+				return nil, err
+			}
+			return event.NewSubscription(func(quit <-chan struct{}) error {
+				defer sub.Unsubscribe()
+				for {
+					select {
+					case log := <-logs:
+						// New log arrived, parse the event and forward to the user
+						event := new({{$contract.Type}}{{.Normalized.Name}})
+						if err := _{{$contract.Type}}.contract.UnpackLog(event, "{{.Original.Name}}", log); err != nil {
+							return err
+						}
+						event.Raw = log
+
+						select {
+						case sink <- event:
+						case err := <-sub.Err():
+							return err
+						case <-quit:
+							return nil
+						}
+					case err := <-sub.Err():
+						return err
+					case <-quit:
+						return nil
+					}
+				}
+			}), nil
+		}
+ 	{{end}}
+{{end}}
+`
+
+// tmplSourceJava is the Java source template use to generate the contract binding
+// based on.
+const tmplSourceJava = `
+// This file is an automatically generated Java binding. Do not modify as any
+// change will likely be lost upon the next re-generation!
+
+package {{.Package}};
+
+import org.ethereum.geth.*;
+import org.ethereum.geth.internal.*;
+
+{{range $contract := .Contracts}}
+	public class {{.Type}} {
+		// ABI is the input ABI used to generate the binding from.
+		public final static String ABI = "{{.InputABI}}";
+
+		{{if .InputBin}}
+			// BYTECODE is the compiled bytecode used for deploying new contracts.
+			public final static byte[] BYTECODE = "{{.InputBin}}".getBytes();
+
+			// deploy deploys a new Ethereum contract, binding an instance of {{.Type}} to it.
+			public static {{.Type}} deploy(TransactOpts auth, EthereumClient client{{range .Constructor.Inputs}}, {{bindtype .Type}} {{.Name}}{{end}}) throws Exception {
+				Interfaces args = Geth.newInterfaces({{(len .Constructor.Inputs)}});
+				{{range $index, $element := .Constructor.Inputs}}
+				  args.set({{$index}}, Geth.newInterface()); args.get({{$index}}).set{{namedtype (bindtype .Type) .Type}}({{.Name}});
+				{{end}}
+				return new {{.Type}}(Geth.deployContract(auth, ABI, BYTECODE, client, args));
+			}
+
+			// Internal constructor used by contract deployment.
+			private {{.Type}}(BoundContract deployment) {
+				this.Address  = deployment.getAddress();
+				this.Deployer = deployment.getDeployer();
+				this.Contract = deployment;
+			}
+		{{end}}
+
+		// Ethereum address where this contract is located at.
+		public final Address Address;
+
+		// Ethereum transaction in which this contract was deployed (if known!).
+		public final Transaction Deployer;
+
+		// Contract instance bound to a blockchain address.
+		private final BoundContract Contract;
+
+		// Creates a new instance of {{.Type}}, bound to a specific deployed contract.
+		public {{.Type}}(Address address, EthereumClient client) throws Exception {
+			this(Geth.bindContract(address, ABI, client));
+		}
+
+		{{range .Calls}}
+			{{if gt (len .Normalized.Outputs) 1}}
+			// {{capitalise .Normalized.Name}}Results is the output of a call to {{.Normalized.Name}}.
+			public class {{capitalise .Normalized.Name}}Results {
+				{{range $index, $item := .Normalized.Outputs}}public {{bindtype .Type}} {{if ne .Name ""}}{{.Name}}{{else}}Return{{$index}}{{end}};
+				{{end}}
+			}
+			{{end}}
+
+			// {{.Normalized.Name}} is a free data retrieval call binding the contract method 0x{{printf "%x" .Original.Id}}.
+			//
+			// Solidity: {{.Original.String}}
+			public {{if gt (len .Normalized.Outputs) 1}}{{capitalise .Normalized.Name}}Results{{else}}{{range .Normalized.Outputs}}{{bindtype .Type}}{{end}}{{end}} {{.Normalized.Name}}(CallOpts opts{{range .Normalized.Inputs}}, {{bindtype .Type}} {{.Name}}{{end}}) throws Exception {
+				Interfaces args = Geth.newInterfaces({{(len .Normalized.Inputs)}});
+				{{range $index, $item := .Normalized.Inputs}}args.set({{$index}}, Geth.newInterface()); args.get({{$index}}).set{{namedtype (bindtype .Type) .Type}}({{.Name}});
+				{{end}}
+
+				Interfaces results = Geth.newInterfaces({{(len .Normalized.Outputs)}});
+				{{range $index, $item := .Normalized.Outputs}}Interface result{{$index}} = Geth.newInterface(); result{{$index}}.setDefault{{namedtype (bindtype .Type) .Type}}(); results.set({{$index}}, result{{$index}});
+				{{end}}
+
+				if (opts == null) {
+					opts = Geth.newCallOpts();
+				}
+				this.Contract.call(opts, results, "{{.Original.Name}}", args);
+				{{if gt (len .Normalized.Outputs) 1}}
+					{{capitalise .Normalized.Name}}Results result = new {{capitalise .Normalized.Name}}Results();
+					{{range $index, $item := .Normalized.Outputs}}result.{{if ne .Name ""}}{{.Name}}{{else}}Return{{$index}}{{end}} = results.get({{$index}}).get{{namedtype (bindtype .Type) .Type}}();
+					{{end}}
+					return result;
+				{{else}}{{range .Normalized.Outputs}}return results.get(0).get{{namedtype (bindtype .Type) .Type}}();{{end}}
+				{{end}}
+			}
+		{{end}}
+
+		{{range .Transacts}}
+			// {{.Normalized.Name}} is a paid mutator transaction binding the contract method 0x{{printf "%x" .Original.Id}}.
+			//
+			// Solidity: {{.Original.String}}
+			public Transaction {{.Normalized.Name}}(TransactOpts opts{{range .Normalized.Inputs}}, {{bindtype .Type}} {{.Name}}{{end}}) throws Exception {
+				Interfaces args = Geth.newInterfaces({{(len .Normalized.Inputs)}});
+				{{range $index, $item := .Normalized.Inputs}}args.set({{$index}}, Geth.newInterface()); args.get({{$index}}).set{{namedtype (bindtype .Type) .Type}}({{.Name}});
+				{{end}}
+
+				return this.Contract.transact(opts, "{{.Original.Name}}"	, args);
+			}
+		{{end}}
+	}
+{{end}}
+`

accounts/abi/bind/topics.go

@@ -0,0 +1,241 @@
+// Copyright 2018 The go-ethereum Authors
+// This file is part of the go-ethereum library.
+//
+// The go-ethereum library is free software: you can redistribute it and/or modify
+// it under the terms of the GNU Lesser General Public License as published by
+// the Free Software Foundation, either version 3 of the License, or
+// (at your option) any later version.
+//
+// The go-ethereum library is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+// GNU Lesser General Public License for more details.
+//
+// You should have received a copy of the GNU Lesser General Public License
+// along with the go-ethereum library. If not, see <http://www.gnu.org/licenses/>.
+
+package bind
+
+import (
+	"encoding/binary"
+	"errors"
+	"fmt"
+	"math/big"
+	"reflect"
+
+	"github.com/ethereum/go-ethereum/accounts/abi"
+	"github.com/ethereum/go-ethereum/common"
+	"github.com/ethereum/go-ethereum/crypto"
+)
+
+// makeTopics converts a filter query argument list into a filter topic set.
+func makeTopics(query ...[]interface{}) ([][]common.Hash, error) {
+	topics := make([][]common.Hash, len(query))
+	for i, filter := range query {
+		for _, rule := range filter {
+			var topic common.Hash
+
+			// Try to generate the topic based on simple types
+			switch rule := rule.(type) {
+			case common.Hash:
+				copy(topic[:], rule[:])
+			case common.Address:
+				copy(topic[common.HashLength-common.AddressLength:], rule[:])
+			case *big.Int:
+				blob := rule.Bytes()
+				copy(topic[common.HashLength-len(blob):], blob)
+			case bool:
+				if rule {
+					topic[common.HashLength-1] = 1
+				}
+			case int8:
+				blob := big.NewInt(int64(rule)).Bytes()
+				copy(topic[common.HashLength-len(blob):], blob)
+			case int16:
+				blob := big.NewInt(int64(rule)).Bytes()
+				copy(topic[common.HashLength-len(blob):], blob)
+			case int32:
+				blob := big.NewInt(int64(rule)).Bytes()
+				copy(topic[common.HashLength-len(blob):], blob)
+			case int64:
+				blob := big.NewInt(rule).Bytes()
+				copy(topic[common.HashLength-len(blob):], blob)
+			case uint8:
+				blob := new(big.Int).SetUint64(uint64(rule)).Bytes()
+				copy(topic[common.HashLength-len(blob):], blob)
+			case uint16:
+				blob := new(big.Int).SetUint64(uint64(rule)).Bytes()
+				copy(topic[common.HashLength-len(blob):], blob)
+			case uint32:
+				blob := new(big.Int).SetUint64(uint64(rule)).Bytes()
+				copy(topic[common.HashLength-len(blob):], blob)
+			case uint64:
+				blob := new(big.Int).SetUint64(rule).Bytes()
+				copy(topic[common.HashLength-len(blob):], blob)
+			case string:
+				hash := crypto.Keccak256Hash([]byte(rule))
+				copy(topic[:], hash[:])
+			case []byte:
+				hash := crypto.Keccak256Hash(rule)
+				copy(topic[:], hash[:])
+
+			default:
+				// Attempt to generate the topic from funky types
+				val := reflect.ValueOf(rule)
+
+				switch {
+
+				// static byte array
+				case val.Kind() == reflect.Array && reflect.TypeOf(rule).Elem().Kind() == reflect.Uint8:
+					reflect.Copy(reflect.ValueOf(topic[:val.Len()]), val)
+
+				default:
+					return nil, fmt.Errorf("unsupported indexed type: %T", rule)
+				}
+			}
+			topics[i] = append(topics[i], topic)
+		}
+	}
+	return topics, nil
+}
+
+// Big batch of reflect types for topic reconstruction.
+var (
+	reflectHash    = reflect.TypeOf(common.Hash{})
+	reflectAddress = reflect.TypeOf(common.Address{})
+	reflectBigInt  = reflect.TypeOf(new(big.Int))
+)
+
+// parseTopics converts the indexed topic fields into actual log field values.
+//
+// Note, dynamic types cannot be reconstructed since they get mapped to Keccak256
+// hashes as the topic value!
+func parseTopics(out interface{}, fields abi.Arguments, topics []common.Hash) error {
+	// Sanity check that the fields and topics match up
+	if len(fields) != len(topics) {
+		return errors.New("topic/field count mismatch")
+	}
+	// Iterate over all the fields and reconstruct them from topics
+	for _, arg := range fields {
+		if !arg.Indexed {
+			return errors.New("non-indexed field in topic reconstruction")
+		}
+		field := reflect.ValueOf(out).Elem().FieldByName(capitalise(arg.Name))
+
+		// Try to parse the topic back into the fields based on primitive types
+		switch field.Kind() {
+		case reflect.Bool:
+			if topics[0][common.HashLength-1] == 1 {
+				field.Set(reflect.ValueOf(true))
+			}
+		case reflect.Int8:
+			num := new(big.Int).SetBytes(topics[0][:])
+			field.Set(reflect.ValueOf(int8(num.Int64())))
+
+		case reflect.Int16:
+			num := new(big.Int).SetBytes(topics[0][:])
+			field.Set(reflect.ValueOf(int16(num.Int64())))
+
+		case reflect.Int32:
+			num := new(big.Int).SetBytes(topics[0][:])
+			field.Set(reflect.ValueOf(int32(num.Int64())))
+
+		case reflect.Int64:
+			num := new(big.Int).SetBytes(topics[0][:])
+			field.Set(reflect.ValueOf(num.Int64()))
+
+		case reflect.Uint8:
+			num := new(big.Int).SetBytes(topics[0][:])
+			field.Set(reflect.ValueOf(uint8(num.Uint64())))
+
+		case reflect.Uint16:
+			num := new(big.Int).SetBytes(topics[0][:])
+			field.Set(reflect.ValueOf(uint16(num.Uint64())))
+
+		case reflect.Uint32:
+			num := new(big.Int).SetBytes(topics[0][:])
+			field.Set(reflect.ValueOf(uint32(num.Uint64())))
+
+		case reflect.Uint64:
+			num := new(big.Int).SetBytes(topics[0][:])
+			field.Set(reflect.ValueOf(num.Uint64()))
+
+		default:
+			// Ran out of plain primitive types, try custom types
+			switch field.Type() {
+			case reflectHash: // Also covers all dynamic types
+				field.Set(reflect.ValueOf(topics[0]))
+
+			case reflectAddress:
+				var addr common.Address
+				copy(addr[:], topics[0][common.HashLength-common.AddressLength:])
+				field.Set(reflect.ValueOf(addr))
+
+			case reflectBigInt:
+				num := new(big.Int).SetBytes(topics[0][:])
+				field.Set(reflect.ValueOf(num))
+
+			default:
+				// Ran out of custom types, try the crazies
+				switch {
+
+				// static byte array
+				case arg.Type.T == abi.FixedBytesTy:
+					reflect.Copy(field, reflect.ValueOf(topics[0][:arg.Type.Size]))
+
+				default:
+					return fmt.Errorf("unsupported indexed type: %v", arg.Type)
+				}
+			}
+		}
+		topics = topics[1:]
+	}
+	return nil
+}
+
+// parseTopicsIntoMap converts the indexed topic field-value pairs into map key-value pairs
+func parseTopicsIntoMap(out map[string]interface{}, fields abi.Arguments, topics []common.Hash) error {
+	// Sanity check that the fields and topics match up
+	if len(fields) != len(topics) {
+		return errors.New("topic/field count mismatch")
+	}
+	// Iterate over all the fields and reconstruct them from topics
+	for _, arg := range fields {
+		if !arg.Indexed {
+			return errors.New("non-indexed field in topic reconstruction")
+		}
+
+		switch arg.Type.T {
+		case abi.BoolTy:
+			out[arg.Name] = topics[0][common.HashLength-1] == 1
+		case abi.IntTy, abi.UintTy:
+			num := new(big.Int).SetBytes(topics[0][:])
+			out[arg.Name] = num
+		case abi.AddressTy:
+			var addr common.Address
+			copy(addr[:], topics[0][common.HashLength-common.AddressLength:])
+			out[arg.Name] = addr
+		case abi.HashTy:
+			out[arg.Name] = topics[0]
+		case abi.FixedBytesTy:
+			out[arg.Name] = topics[0][:]
+		case abi.StringTy, abi.BytesTy, abi.SliceTy, abi.ArrayTy:
+			// Array types (including strings and bytes) have their keccak256 hashes stored in the topic- not a hash
+			// whose bytes can be decoded to the actual value- so the best we can do is retrieve that hash
+			out[arg.Name] = topics[0]
+		case abi.FunctionTy:
+			if garbage := binary.BigEndian.Uint64(topics[0][0:8]); garbage != 0 {
+				return fmt.Errorf("bind: got improperly encoded function type, got %v", topics[0].Bytes())
+			}
+			var tmp [24]byte
+			copy(tmp[:], topics[0][8:32])
+			out[arg.Name] = tmp
+		default: // Not handling tuples
+			return fmt.Errorf("unsupported indexed type: %v", arg.Type)
+		}
+
+		topics = topics[1:]
+	}
+
+	return nil
+}

accounts/abi/bind/topics_test.go

@@ -0,0 +1,103 @@
+// Copyright 2018 The go-ethereum Authors
+// This file is part of the go-ethereum library.
+//
+// The go-ethereum library is free software: you can redistribute it and/or modify
+// it under the terms of the GNU Lesser General Public License as published by
+// the Free Software Foundation, either version 3 of the License, or
+// (at your option) any later version.
+//
+// The go-ethereum library is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+// GNU Lesser General Public License for more details.
+//
+// You should have received a copy of the GNU Lesser General Public License
+// along with the go-ethereum library. If not, see <http://www.gnu.org/licenses/>.
+
+package bind
+
+import (
+	"reflect"
+	"testing"
+
+	"github.com/ethereum/go-ethereum/accounts/abi"
+	"github.com/ethereum/go-ethereum/common"
+)
+
+func TestMakeTopics(t *testing.T) {
+	type args struct {
+		query [][]interface{}
+	}
+	tests := []struct {
+		name    string
+		args    args
+		want    [][]common.Hash
+		wantErr bool
+	}{
+		{
+			"support fixed byte types, right padded to 32 bytes",
+			args{[][]interface{}{{[5]byte{1, 2, 3, 4, 5}}}},
+			[][]common.Hash{{common.Hash{1, 2, 3, 4, 5}}},
+			false,
+		},
+	}
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			got, err := makeTopics(tt.args.query...)
+			if (err != nil) != tt.wantErr {
+				t.Errorf("makeTopics() error = %v, wantErr %v", err, tt.wantErr)
+				return
+			}
+			if !reflect.DeepEqual(got, tt.want) {
+				t.Errorf("makeTopics() = %v, want %v", got, tt.want)
+			}
+		})
+	}
+}
+
+func TestParseTopics(t *testing.T) {
+	type bytesStruct struct {
+		StaticBytes [5]byte
+	}
+	bytesType, _ := abi.NewType("bytes5", nil)
+	type args struct {
+		createObj func() interface{}
+		resultObj func() interface{}
+		fields    abi.Arguments
+		topics    []common.Hash
+	}
+	tests := []struct {
+		name    string
+		args    args
+		wantErr bool
+	}{
+		{
+			name: "support fixed byte types, right padded to 32 bytes",
+			args: args{
+				createObj: func() interface{} { return &bytesStruct{} },
+				resultObj: func() interface{} { return &bytesStruct{StaticBytes: [5]byte{1, 2, 3, 4, 5}} },
+				fields: abi.Arguments{abi.Argument{
+					Name:    "staticBytes",
+					Type:    bytesType,
+					Indexed: true,
+				}},
+				topics: []common.Hash{
+					{1, 2, 3, 4, 5},
+				},
+			},
+			wantErr: false,
+		},
+	}
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			createObj := tt.args.createObj()
+			if err := parseTopics(createObj, tt.args.fields, tt.args.topics); (err != nil) != tt.wantErr {
+				t.Errorf("parseTopics() error = %v, wantErr %v", err, tt.wantErr)
+			}
+			resultObj := tt.args.resultObj()
+			if !reflect.DeepEqual(createObj, resultObj) {
+				t.Errorf("parseTopics() = %v, want %v", createObj, resultObj)
+			}
+		})
+	}
+}

accounts/abi/bind/util.go

@@ -0,0 +1,76 @@
+// Copyright 2016 The go-ethereum Authors
+// This file is part of the go-ethereum library.
+//
+// The go-ethereum library is free software: you can redistribute it and/or modify
+// it under the terms of the GNU Lesser General Public License as published by
+// the Free Software Foundation, either version 3 of the License, or
+// (at your option) any later version.
+//
+// The go-ethereum library is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+// GNU Lesser General Public License for more details.
+//
+// You should have received a copy of the GNU Lesser General Public License
+// along with the go-ethereum library. If not, see <http://www.gnu.org/licenses/>.
+
+package bind
+
+import (
+	"context"
+	"fmt"
+	"time"
+
+	"github.com/ethereum/go-ethereum/common"
+	"github.com/ethereum/go-ethereum/core/types"
+	"github.com/ethereum/go-ethereum/log"
+)
+
+// WaitMined waits for tx to be mined on the blockchain.
+// It stops waiting when the context is canceled.
+func WaitMined(ctx context.Context, b DeployBackend, tx *types.Transaction) (*types.Receipt, error) {
+	queryTicker := time.NewTicker(time.Second)
+	defer queryTicker.Stop()
+
+	logger := log.New("hash", tx.Hash())
+	for {
+		receipt, err := b.TransactionReceipt(ctx, tx.Hash())
+		if receipt != nil {
+			return receipt, nil
+		}
+		if err != nil {
+			logger.Trace("Receipt retrieval failed", "err", err)
+		} else {
+			logger.Trace("Transaction not yet mined")
+		}
+		// Wait for the next round.
+		select {
+		case <-ctx.Done():
+			return nil, ctx.Err()
+		case <-queryTicker.C:
+		}
+	}
+}
+
+// WaitDeployed waits for a contract deployment transaction and returns the on-chain
+// contract address when it is mined. It stops waiting when ctx is canceled.
+func WaitDeployed(ctx context.Context, b DeployBackend, tx *types.Transaction) (common.Address, error) {
+	if tx.To() != nil {
+		return common.Address{}, fmt.Errorf("tx is not contract creation")
+	}
+	receipt, err := WaitMined(ctx, b, tx)
+	if err != nil {
+		return common.Address{}, err
+	}
+	if receipt.ContractAddress == (common.Address{}) {
+		return common.Address{}, fmt.Errorf("zero address")
+	}
+	// Check that code has indeed been deployed at the address.
+	// This matters on pre-Homestead chains: OOG in the constructor
+	// could leave an empty account behind.
+	code, err := b.CodeAt(ctx, receipt.ContractAddress, nil)
+	if err == nil && len(code) == 0 {
+		err = ErrNoCodeAfterDeploy
+	}
+	return receipt.ContractAddress, err
+}

accounts/abi/bind/util_test.go

@@ -0,0 +1,94 @@
+// Copyright 2016 The go-ethereum Authors
+// This file is part of the go-ethereum library.
+//
+// The go-ethereum library is free software: you can redistribute it and/or modify
+// it under the terms of the GNU Lesser General Public License as published by
+// the Free Software Foundation, either version 3 of the License, or
+// (at your option) any later version.
+//
+// The go-ethereum library is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+// GNU Lesser General Public License for more details.
+//
+// You should have received a copy of the GNU Lesser General Public License
+// along with the go-ethereum library. If not, see <http://www.gnu.org/licenses/>.
+
+package bind_test
+
+import (
+	"context"
+	"math/big"
+	"testing"
+	"time"
+
+	"github.com/ethereum/go-ethereum/accounts/abi/bind"
+	"github.com/ethereum/go-ethereum/accounts/abi/bind/backends"
+	"github.com/ethereum/go-ethereum/common"
+	"github.com/ethereum/go-ethereum/core"
+	"github.com/ethereum/go-ethereum/core/types"
+	"github.com/ethereum/go-ethereum/crypto"
+)
+
+var testKey, _ = crypto.HexToECDSA("b71c71a67e1177ad4e901695e1b4b9ee17ae16c6668d313eac2f96dbcda3f291")
+
+var waitDeployedTests = map[string]struct {
+	code        string
+	gas         uint64
+	wantAddress common.Address
+	wantErr     error
+}{
+	"successful deploy": {
+		code:        `6060604052600a8060106000396000f360606040526008565b00`,
+		gas:         3000000,
+		wantAddress: common.HexToAddress("0x3a220f351252089d385b29beca14e27f204c296a"),
+	},
+	"empty code": {
+		code:        ``,
+		gas:         300000,
+		wantErr:     bind.ErrNoCodeAfterDeploy,
+		wantAddress: common.HexToAddress("0x3a220f351252089d385b29beca14e27f204c296a"),
+	},
+}
+
+func TestWaitDeployed(t *testing.T) {
+	for name, test := range waitDeployedTests {
+		backend := backends.NewSimulatedBackend(
+			core.GenesisAlloc{
+				crypto.PubkeyToAddress(testKey.PublicKey): {Balance: big.NewInt(10000000000)},
+			}, 10000000,
+		)
+
+		// Create the transaction.
+		tx := types.NewContractCreation(0, big.NewInt(0), test.gas, big.NewInt(1), common.FromHex(test.code))
+		tx, _ = types.SignTx(tx, types.HomesteadSigner{}, testKey)
+
+		// Wait for it to get mined in the background.
+		var (
+			err     error
+			address common.Address
+			mined   = make(chan struct{})
+			ctx     = context.Background()
+		)
+		go func() {
+			address, err = bind.WaitDeployed(ctx, backend, tx)
+			close(mined)
+		}()
+
+		// Send and mine the transaction.
+		backend.SendTransaction(ctx, tx)
+		backend.Commit()
+
+		select {
+		case <-mined:
+			if err != test.wantErr {
+				t.Errorf("test %q: error mismatch: got %q, want %q", name, err, test.wantErr)
+			}
+			if address != test.wantAddress {
+				t.Errorf("test %q: unexpected contract address %s", name, address.Hex())
+			}
+		case <-time.After(2 * time.Second):
+			t.Errorf("test %q: timeout", name)
+		}
+	}
+}

accounts/abi/doc.go

@@ -0,0 +1,26 @@
+// Copyright 2015 The go-ethereum Authors
+// This file is part of the go-ethereum library.
+//
+// The go-ethereum library is free software: you can redistribute it and/or modify
+// it under the terms of the GNU Lesser General Public License as published by
+// the Free Software Foundation, either version 3 of the License, or
+// (at your option) any later version.
+//
+// The go-ethereum library is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+// GNU Lesser General Public License for more details.
+//
+// You should have received a copy of the GNU Lesser General Public License
+// along with the go-ethereum library. If not, see <http://www.gnu.org/licenses/>.
+
+// Package abi implements the Ethereum ABI (Application Binary
+// Interface).
+//
+// The Ethereum ABI is strongly typed, known at compile time
+// and static. This ABI will handle basic type casting; unsigned
+// to signed and visa versa. It does not handle slice casting such
+// as unsigned slice to signed slice. Bit size type casting is also
+// handled. ints with a bit size of 32 will be properly cast to int256,
+// etc.
+package abi

accounts/abi/error.go

@@ -0,0 +1,84 @@
+// Copyright 2016 The go-ethereum Authors
+// This file is part of the go-ethereum library.
+//
+// The go-ethereum library is free software: you can redistribute it and/or modify
+// it under the terms of the GNU Lesser General Public License as published by
+// the Free Software Foundation, either version 3 of the License, or
+// (at your option) any later version.
+//
+// The go-ethereum library is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+// GNU Lesser General Public License for more details.
+//
+// You should have received a copy of the GNU Lesser General Public License
+// along with the go-ethereum library. If not, see <http://www.gnu.org/licenses/>.
+
+package abi
+
+import (
+	"errors"
+	"fmt"
+	"reflect"
+)
+
+var (
+	errBadBool = errors.New("abi: improperly encoded boolean value")
+)
+
+// formatSliceString formats the reflection kind with the given slice size
+// and returns a formatted string representation.
+func formatSliceString(kind reflect.Kind, sliceSize int) string {
+	if sliceSize == -1 {
+		return fmt.Sprintf("[]%v", kind)
+	}
+	return fmt.Sprintf("[%d]%v", sliceSize, kind)
+}
+
+// sliceTypeCheck checks that the given slice can by assigned to the reflection
+// type in t.
+func sliceTypeCheck(t Type, val reflect.Value) error {
+	if val.Kind() != reflect.Slice && val.Kind() != reflect.Array {
+		return typeErr(formatSliceString(t.Kind, t.Size), val.Type())
+	}
+
+	if t.T == ArrayTy && val.Len() != t.Size {
+		return typeErr(formatSliceString(t.Elem.Kind, t.Size), formatSliceString(val.Type().Elem().Kind(), val.Len()))
+	}
+
+	if t.Elem.T == SliceTy {
+		if val.Len() > 0 {
+			return sliceTypeCheck(*t.Elem, val.Index(0))
+		}
+	} else if t.Elem.T == ArrayTy {
+		return sliceTypeCheck(*t.Elem, val.Index(0))
+	}
+
+	if elemKind := val.Type().Elem().Kind(); elemKind != t.Elem.Kind {
+		return typeErr(formatSliceString(t.Elem.Kind, t.Size), val.Type())
+	}
+	return nil
+}
+
+// typeCheck checks that the given reflection value can be assigned to the reflection
+// type in t.
+func typeCheck(t Type, value reflect.Value) error {
+	if t.T == SliceTy || t.T == ArrayTy {
+		return sliceTypeCheck(t, value)
+	}
+
+	// Check base type validity. Element types will be checked later on.
+	if t.Kind != value.Kind() {
+		return typeErr(t.Kind, value.Kind())
+	} else if t.T == FixedBytesTy && t.Size != value.Len() {
+		return typeErr(t.Type, value.Type())
+	} else {
+		return nil
+	}
+
+}
+
+// typeErr returns a formatted type casting error.
+func typeErr(expected, got interface{}) error {
+	return fmt.Errorf("abi: cannot use %v as type %v as argument", got, expected)
+}

accounts/abi/event.go

@@ -0,0 +1,57 @@
+// Copyright 2016 The go-ethereum Authors
+// This file is part of the go-ethereum library.
+//
+// The go-ethereum library is free software: you can redistribute it and/or modify
+// it under the terms of the GNU Lesser General Public License as published by
+// the Free Software Foundation, either version 3 of the License, or
+// (at your option) any later version.
+//
+// The go-ethereum library is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+// GNU Lesser General Public License for more details.
+//
+// You should have received a copy of the GNU Lesser General Public License
+// along with the go-ethereum library. If not, see <http://www.gnu.org/licenses/>.
+
+package abi
+
+import (
+	"fmt"
+	"strings"
+
+	"github.com/ethereum/go-ethereum/common"
+	"github.com/ethereum/go-ethereum/crypto"
+)
+
+// Event is an event potentially triggered by the EVM's LOG mechanism. The Event
+// holds type information (inputs) about the yielded output. Anonymous events
+// don't get the signature canonical representation as the first LOG topic.
+type Event struct {
+	Name      string
+	Anonymous bool
+	Inputs    Arguments
+}
+
+func (e Event) String() string {
+	inputs := make([]string, len(e.Inputs))
+	for i, input := range e.Inputs {
+		inputs[i] = fmt.Sprintf("%v %v", input.Type, input.Name)
+		if input.Indexed {
+			inputs[i] = fmt.Sprintf("%v indexed %v", input.Type, input.Name)
+		}
+	}
+	return fmt.Sprintf("event %v(%v)", e.Name, strings.Join(inputs, ", "))
+}
+
+// Id returns the canonical representation of the event's signature used by the
+// abi definition to identify event names and types.
+func (e Event) Id() common.Hash {
+	types := make([]string, len(e.Inputs))
+	i := 0
+	for _, input := range e.Inputs {
+		types[i] = input.Type.String()
+		i++
+	}
+	return common.BytesToHash(crypto.Keccak256([]byte(fmt.Sprintf("%v(%v)", e.Name, strings.Join(types, ",")))))
+}

accounts/abi/event_test.go

@@ -0,0 +1,428 @@
+// Copyright 2016 The go-ethereum Authors
+// This file is part of the go-ethereum library.
+//
+// The go-ethereum library is free software: you can redistribute it and/or modify
+// it under the terms of the GNU Lesser General Public License as published by
+// the Free Software Foundation, either version 3 of the License, or
+// (at your option) any later version.
+//
+// The go-ethereum library is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+// GNU Lesser General Public License for more details.
+//
+// You should have received a copy of the GNU Lesser General Public License
+// along with the go-ethereum library. If not, see <http://www.gnu.org/licenses/>.
+
+package abi
+
+import (
+	"bytes"
+	"encoding/hex"
+	"encoding/json"
+	"math/big"
+	"reflect"
+	"strings"
+	"testing"
+
+	"github.com/ethereum/go-ethereum/common"
+	"github.com/ethereum/go-ethereum/crypto"
+	"github.com/stretchr/testify/assert"
+	"github.com/stretchr/testify/require"
+)
+
+var jsonEventTransfer = []byte(`{
+  "anonymous": false,
+  "inputs": [
+    {
+      "indexed": true, "name": "from", "type": "address"
+    }, {
+      "indexed": true, "name": "to", "type": "address"
+    }, {
+      "indexed": false, "name": "value", "type": "uint256"
+  }],
+  "name": "Transfer",
+  "type": "event"
+}`)
+
+var jsonEventPledge = []byte(`{
+  "anonymous": false,
+  "inputs": [{
+      "indexed": false, "name": "who", "type": "address"
+    }, {
+      "indexed": false, "name": "wad", "type": "uint128"
+    }, {
+      "indexed": false, "name": "currency", "type": "bytes3"
+  }],
+  "name": "Pledge",
+  "type": "event"
+}`)
+
+var jsonEventMixedCase = []byte(`{
+	"anonymous": false,
+	"inputs": [{
+		"indexed": false, "name": "value", "type": "uint256"
+	  }, {
+		"indexed": false, "name": "_value", "type": "uint256"
+	  }, {
+		"indexed": false, "name": "Value", "type": "uint256"
+	}],
+	"name": "MixedCase",
+	"type": "event"
+  }`)
+
+// 1000000
+var transferData1 = "00000000000000000000000000000000000000000000000000000000000f4240"
+
+// "0x00Ce0d46d924CC8437c806721496599FC3FFA268", 2218516807680, "usd"
+var pledgeData1 = "00000000000000000000000000ce0d46d924cc8437c806721496599fc3ffa2680000000000000000000000000000000000000000000000000000020489e800007573640000000000000000000000000000000000000000000000000000000000"
+
+// 1000000,2218516807680,1000001
+var mixedCaseData1 = "00000000000000000000000000000000000000000000000000000000000f42400000000000000000000000000000000000000000000000000000020489e8000000000000000000000000000000000000000000000000000000000000000f4241"
+
+func TestEventId(t *testing.T) {
+	var table = []struct {
+		definition   string
+		expectations map[string]common.Hash
+	}{
+		{
+			definition: `[
+			{ "type" : "event", "name" : "Balance", "inputs": [{ "name" : "in", "type": "uint256" }] },
+			{ "type" : "event", "name" : "Check", "inputs": [{ "name" : "t", "type": "address" }, { "name": "b", "type": "uint256" }] }
+			]`,
+			expectations: map[string]common.Hash{
+				"Balance": crypto.Keccak256Hash([]byte("Balance(uint256)")),
+				"Check":   crypto.Keccak256Hash([]byte("Check(address,uint256)")),
+			},
+		},
+	}
+
+	for _, test := range table {
+		abi, err := JSON(strings.NewReader(test.definition))
+		if err != nil {
+			t.Fatal(err)
+		}
+
+		for name, event := range abi.Events {
+			if event.Id() != test.expectations[name] {
+				t.Errorf("expected id to be %x, got %x", test.expectations[name], event.Id())
+			}
+		}
+	}
+}
+
+func TestEventString(t *testing.T) {
+	var table = []struct {
+		definition   string
+		expectations map[string]string
+	}{
+		{
+			definition: `[
+			{ "type" : "event", "name" : "Balance", "inputs": [{ "name" : "in", "type": "uint256" }] },
+			{ "type" : "event", "name" : "Check", "inputs": [{ "name" : "t", "type": "address" }, { "name": "b", "type": "uint256" }] },
+			{ "type" : "event", "name" : "Transfer", "inputs": [{ "name": "from", "type": "address", "indexed": true }, { "name": "to", "type": "address", "indexed": true }, { "name": "value", "type": "uint256" }] }
+			]`,
+			expectations: map[string]string{
+				"Balance":  "event Balance(uint256 in)",
+				"Check":    "event Check(address t, uint256 b)",
+				"Transfer": "event Transfer(address indexed from, address indexed to, uint256 value)",
+			},
+		},
+	}
+
+	for _, test := range table {
+		abi, err := JSON(strings.NewReader(test.definition))
+		if err != nil {
+			t.Fatal(err)
+		}
+
+		for name, event := range abi.Events {
+			if event.String() != test.expectations[name] {
+				t.Errorf("expected string to be %s, got %s", test.expectations[name], event.String())
+			}
+		}
+	}
+}
+
+// TestEventMultiValueWithArrayUnpack verifies that array fields will be counted after parsing array.
+func TestEventMultiValueWithArrayUnpack(t *testing.T) {
+	definition := `[{"name": "test", "type": "event", "inputs": [{"indexed": false, "name":"value1", "type":"uint8[2]"},{"indexed": false, "name":"value2", "type":"uint8"}]}]`
+	type testStruct struct {
+		Value1 [2]uint8
+		Value2 uint8
+	}
+	abi, err := JSON(strings.NewReader(definition))
+	require.NoError(t, err)
+	var b bytes.Buffer
+	var i uint8 = 1
+	for ; i <= 3; i++ {
+		b.Write(packNum(reflect.ValueOf(i)))
+	}
+	var rst testStruct
+	require.NoError(t, abi.Unpack(&rst, "test", b.Bytes()))
+	require.Equal(t, [2]uint8{1, 2}, rst.Value1)
+	require.Equal(t, uint8(3), rst.Value2)
+}
+
+func TestEventTupleUnpack(t *testing.T) {
+
+	type EventTransfer struct {
+		Value *big.Int
+	}
+
+	type EventTransferWithTag struct {
+		// this is valid because `value` is not exportable,
+		// so value is only unmarshalled into `Value1`.
+		value  *big.Int
+		Value1 *big.Int `abi:"value"`
+	}
+
+	type BadEventTransferWithSameFieldAndTag struct {
+		Value  *big.Int
+		Value1 *big.Int `abi:"value"`
+	}
+
+	type BadEventTransferWithDuplicatedTag struct {
+		Value1 *big.Int `abi:"value"`
+		Value2 *big.Int `abi:"value"`
+	}
+
+	type BadEventTransferWithEmptyTag struct {
+		Value *big.Int `abi:""`
+	}
+
+	type EventPledge struct {
+		Who      common.Address
+		Wad      *big.Int
+		Currency [3]byte
+	}
+
+	type BadEventPledge struct {
+		Who      string
+		Wad      int
+		Currency [3]byte
+	}
+
+	type EventMixedCase struct {
+		Value1 *big.Int `abi:"value"`
+		Value2 *big.Int `abi:"_value"`
+		Value3 *big.Int `abi:"Value"`
+	}
+
+	bigint := new(big.Int)
+	bigintExpected := big.NewInt(1000000)
+	bigintExpected2 := big.NewInt(2218516807680)
+	bigintExpected3 := big.NewInt(1000001)
+	addr := common.HexToAddress("0x00Ce0d46d924CC8437c806721496599FC3FFA268")
+	var testCases = []struct {
+		data     string
+		dest     interface{}
+		expected interface{}
+		jsonLog  []byte
+		error    string
+		name     string
+	}{{
+		transferData1,
+		&EventTransfer{},
+		&EventTransfer{Value: bigintExpected},
+		jsonEventTransfer,
+		"",
+		"Can unpack ERC20 Transfer event into structure",
+	}, {
+		transferData1,
+		&[]interface{}{&bigint},
+		&[]interface{}{&bigintExpected},
+		jsonEventTransfer,
+		"",
+		"Can unpack ERC20 Transfer event into slice",
+	}, {
+		transferData1,
+		&EventTransferWithTag{},
+		&EventTransferWithTag{Value1: bigintExpected},
+		jsonEventTransfer,
+		"",
+		"Can unpack ERC20 Transfer event into structure with abi: tag",
+	}, {
+		transferData1,
+		&BadEventTransferWithDuplicatedTag{},
+		&BadEventTransferWithDuplicatedTag{},
+		jsonEventTransfer,
+		"struct: abi tag in 'Value2' already mapped",
+		"Can not unpack ERC20 Transfer event with duplicated abi tag",
+	}, {
+		transferData1,
+		&BadEventTransferWithSameFieldAndTag{},
+		&BadEventTransferWithSameFieldAndTag{},
+		jsonEventTransfer,
+		"abi: multiple variables maps to the same abi field 'value'",
+		"Can not unpack ERC20 Transfer event with a field and a tag mapping to the same abi variable",
+	}, {
+		transferData1,
+		&BadEventTransferWithEmptyTag{},
+		&BadEventTransferWithEmptyTag{},
+		jsonEventTransfer,
+		"struct: abi tag in 'Value' is empty",
+		"Can not unpack ERC20 Transfer event with an empty tag",
+	}, {
+		pledgeData1,
+		&EventPledge{},
+		&EventPledge{
+			addr,
+			bigintExpected2,
+			[3]byte{'u', 's', 'd'}},
+		jsonEventPledge,
+		"",
+		"Can unpack Pledge event into structure",
+	}, {
+		pledgeData1,
+		&[]interface{}{&common.Address{}, &bigint, &[3]byte{}},
+		&[]interface{}{
+			&addr,
+			&bigintExpected2,
+			&[3]byte{'u', 's', 'd'}},
+		jsonEventPledge,
+		"",
+		"Can unpack Pledge event into slice",
+	}, {
+		pledgeData1,
+		&[3]interface{}{&common.Address{}, &bigint, &[3]byte{}},
+		&[3]interface{}{
+			&addr,
+			&bigintExpected2,
+			&[3]byte{'u', 's', 'd'}},
+		jsonEventPledge,
+		"",
+		"Can unpack Pledge event into an array",
+	}, {
+		pledgeData1,
+		&[]interface{}{new(int), 0, 0},
+		&[]interface{}{},
+		jsonEventPledge,
+		"abi: cannot unmarshal common.Address in to int",
+		"Can not unpack Pledge event into slice with wrong types",
+	}, {
+		pledgeData1,
+		&BadEventPledge{},
+		&BadEventPledge{},
+		jsonEventPledge,
+		"abi: cannot unmarshal common.Address in to string",
+		"Can not unpack Pledge event into struct with wrong filed types",
+	}, {
+		pledgeData1,
+		&[]interface{}{common.Address{}, new(big.Int)},
+		&[]interface{}{},
+		jsonEventPledge,
+		"abi: insufficient number of elements in the list/array for unpack, want 3, got 2",
+		"Can not unpack Pledge event into too short slice",
+	}, {
+		pledgeData1,
+		new(map[string]interface{}),
+		&[]interface{}{},
+		jsonEventPledge,
+		"abi: cannot unmarshal tuple into map[string]interface {}",
+		"Can not unpack Pledge event into map",
+	}, {
+		mixedCaseData1,
+		&EventMixedCase{},
+		&EventMixedCase{Value1: bigintExpected, Value2: bigintExpected2, Value3: bigintExpected3},
+		jsonEventMixedCase,
+		"",
+		"Can unpack abi variables with mixed case",
+	}}
+
+	for _, tc := range testCases {
+		assert := assert.New(t)
+		tc := tc
+		t.Run(tc.name, func(t *testing.T) {
+			err := unpackTestEventData(tc.dest, tc.data, tc.jsonLog, assert)
+			if tc.error == "" {
+				assert.Nil(err, "Should be able to unpack event data.")
+				assert.Equal(tc.expected, tc.dest, tc.name)
+			} else {
+				assert.EqualError(err, tc.error, tc.name)
+			}
+		})
+	}
+}
+
+func unpackTestEventData(dest interface{}, hexData string, jsonEvent []byte, assert *assert.Assertions) error {
+	data, err := hex.DecodeString(hexData)
+	assert.NoError(err, "Hex data should be a correct hex-string")
+	var e Event
+	assert.NoError(json.Unmarshal(jsonEvent, &e), "Should be able to unmarshal event ABI")
+	a := ABI{Events: map[string]Event{"e": e}}
+	return a.Unpack(dest, "e", data)
+}
+
+/*
+Taken from
+https://github.com/ethereum/go-ethereum/pull/15568
+*/
+
+type testResult struct {
+	Values [2]*big.Int
+	Value1 *big.Int
+	Value2 *big.Int
+}
+
+type testCase struct {
+	definition string
+	want       testResult
+}
+
+func (tc testCase) encoded(intType, arrayType Type) []byte {
+	var b bytes.Buffer
+	if tc.want.Value1 != nil {
+		val, _ := intType.pack(reflect.ValueOf(tc.want.Value1))
+		b.Write(val)
+	}
+
+	if !reflect.DeepEqual(tc.want.Values, [2]*big.Int{nil, nil}) {
+		val, _ := arrayType.pack(reflect.ValueOf(tc.want.Values))
+		b.Write(val)
+	}
+	if tc.want.Value2 != nil {
+		val, _ := intType.pack(reflect.ValueOf(tc.want.Value2))
+		b.Write(val)
+	}
+	return b.Bytes()
+}
+
+// TestEventUnpackIndexed verifies that indexed field will be skipped by event decoder.
+func TestEventUnpackIndexed(t *testing.T) {
+	definition := `[{"name": "test", "type": "event", "inputs": [{"indexed": true, "name":"value1", "type":"uint8"},{"indexed": false, "name":"value2", "type":"uint8"}]}]`
+	type testStruct struct {
+		Value1 uint8
+		Value2 uint8
+	}
+	abi, err := JSON(strings.NewReader(definition))
+	require.NoError(t, err)
+	var b bytes.Buffer
+	b.Write(packNum(reflect.ValueOf(uint8(8))))
+	var rst testStruct
+	require.NoError(t, abi.Unpack(&rst, "test", b.Bytes()))
+	require.Equal(t, uint8(0), rst.Value1)
+	require.Equal(t, uint8(8), rst.Value2)
+}
+
+// TestEventIndexedWithArrayUnpack verifies that decoder will not overlow when static array is indexed input.
+func TestEventIndexedWithArrayUnpack(t *testing.T) {
+	definition := `[{"name": "test", "type": "event", "inputs": [{"indexed": true, "name":"value1", "type":"uint8[2]"},{"indexed": false, "name":"value2", "type":"string"}]}]`
+	type testStruct struct {
+		Value1 [2]uint8
+		Value2 string
+	}
+	abi, err := JSON(strings.NewReader(definition))
+	require.NoError(t, err)
+	var b bytes.Buffer
+	stringOut := "abc"
+	// number of fields that will be encoded * 32
+	b.Write(packNum(reflect.ValueOf(32)))
+	b.Write(packNum(reflect.ValueOf(len(stringOut))))
+	b.Write(common.RightPadBytes([]byte(stringOut), 32))
+
+	var rst testStruct
+	require.NoError(t, abi.Unpack(&rst, "test", b.Bytes()))
+	require.Equal(t, [2]uint8{0, 0}, rst.Value1)
+	require.Equal(t, stringOut, rst.Value2)
+}

accounts/abi/method.go

@@ -0,0 +1,77 @@
+// Copyright 2015 The go-ethereum Authors
+// This file is part of the go-ethereum library.
+//
+// The go-ethereum library is free software: you can redistribute it and/or modify
+// it under the terms of the GNU Lesser General Public License as published by
+// the Free Software Foundation, either version 3 of the License, or
+// (at your option) any later version.
+//
+// The go-ethereum library is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+// GNU Lesser General Public License for more details.
+//
+// You should have received a copy of the GNU Lesser General Public License
+// along with the go-ethereum library. If not, see <http://www.gnu.org/licenses/>.
+
+package abi
+
+import (
+	"fmt"
+	"strings"
+
+	"github.com/ethereum/go-ethereum/crypto"
+)
+
+// Method represents a callable given a `Name` and whether the method is a constant.
+// If the method is `Const` no transaction needs to be created for this
+// particular Method call. It can easily be simulated using a local VM.
+// For example a `Balance()` method only needs to retrieve something
+// from the storage and therefor requires no Tx to be send to the
+// network. A method such as `Transact` does require a Tx and thus will
+// be flagged `true`.
+// Input specifies the required input parameters for this gives method.
+type Method struct {
+	Name    string
+	Const   bool
+	Inputs  Arguments
+	Outputs Arguments
+}
+
+// Sig returns the methods string signature according to the ABI spec.
+//
+// Example
+//
+//     function foo(uint32 a, int b)    =    "foo(uint32,int256)"
+//
+// Please note that "int" is substitute for its canonical representation "int256"
+func (method Method) Sig() string {
+	types := make([]string, len(method.Inputs))
+	for i, input := range method.Inputs {
+		types[i] = input.Type.String()
+	}
+	return fmt.Sprintf("%v(%v)", method.Name, strings.Join(types, ","))
+}
+
+func (method Method) String() string {
+	inputs := make([]string, len(method.Inputs))
+	for i, input := range method.Inputs {
+		inputs[i] = fmt.Sprintf("%v %v", input.Type, input.Name)
+	}
+	outputs := make([]string, len(method.Outputs))
+	for i, output := range method.Outputs {
+		outputs[i] = output.Type.String()
+		if len(output.Name) > 0 {
+			outputs[i] += fmt.Sprintf(" %v", output.Name)
+		}
+	}
+	constant := ""
+	if method.Const {
+		constant = "constant "
+	}
+	return fmt.Sprintf("function %v(%v) %sreturns(%v)", method.Name, strings.Join(inputs, ", "), constant, strings.Join(outputs, ", "))
+}
+
+func (method Method) Id() []byte {
+	return crypto.Keccak256([]byte(method.Sig()))[:4]
+}

accounts/abi/method_test.go

@@ -0,0 +1,61 @@
+// Copyright 2016 The go-ethereum Authors
+// This file is part of the go-ethereum library.
+//
+// The go-ethereum library is free software: you can redistribute it and/or modify
+// it under the terms of the GNU Lesser General Public License as published by
+// the Free Software Foundation, either version 3 of the License, or
+// (at your option) any later version.
+//
+// The go-ethereum library is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+// GNU Lesser General Public License for more details.
+//
+// You should have received a copy of the GNU Lesser General Public License
+// along with the go-ethereum library. If not, see <http://www.gnu.org/licenses/>.
+
+package abi
+
+import (
+	"strings"
+	"testing"
+)
+
+const methoddata = `
+[
+	{ "type" : "function", "name" : "balance", "constant" : true },
+	{ "type" : "function", "name" : "send", "constant" : false, "inputs" : [ { "name" : "amount", "type" : "uint256" } ] },
+	{ "type" : "function", "name" : "transfer", "constant" : false, "inputs" : [ { "name" : "from", "type" : "address" }, { "name" : "to", "type" : "address" }, { "name" : "value", "type" : "uint256" } ], "outputs" : [ { "name" : "success", "type" : "bool" } ]  }
+]`
+
+func TestMethodString(t *testing.T) {
+	var table = []struct {
+		method      string
+		expectation string
+	}{
+		{
+			method:      "balance",
+			expectation: "function balance() constant returns()",
+		},
+		{
+			method:      "send",
+			expectation: "function send(uint256 amount) returns()",
+		},
+		{
+			method:      "transfer",
+			expectation: "function transfer(address from, address to, uint256 value) returns(bool success)",
+		},
+	}
+
+	abi, err := JSON(strings.NewReader(methoddata))
+	if err != nil {
+		t.Fatal(err)
+	}
+
+	for _, test := range table {
+		got := abi.Methods[test.method].String()
+		if got != test.expectation {
+			t.Errorf("expected string to be %s, got %s", test.expectation, got)
+		}
+	}
+}

accounts/abi/numbers.go

@@ -0,0 +1,44 @@
+// Copyright 2015 The go-ethereum Authors
+// This file is part of the go-ethereum library.
+//
+// The go-ethereum library is free software: you can redistribute it and/or modify
+// it under the terms of the GNU Lesser General Public License as published by
+// the Free Software Foundation, either version 3 of the License, or
+// (at your option) any later version.
+//
+// The go-ethereum library is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+// GNU Lesser General Public License for more details.
+//
+// You should have received a copy of the GNU Lesser General Public License
+// along with the go-ethereum library. If not, see <http://www.gnu.org/licenses/>.
+
+package abi
+
+import (
+	"math/big"
+	"reflect"
+
+	"github.com/ethereum/go-ethereum/common"
+	"github.com/ethereum/go-ethereum/common/math"
+)
+
+var (
+	bigT      = reflect.TypeOf(&big.Int{})
+	derefbigT = reflect.TypeOf(big.Int{})
+	uint8T    = reflect.TypeOf(uint8(0))
+	uint16T   = reflect.TypeOf(uint16(0))
+	uint32T   = reflect.TypeOf(uint32(0))
+	uint64T   = reflect.TypeOf(uint64(0))
+	int8T     = reflect.TypeOf(int8(0))
+	int16T    = reflect.TypeOf(int16(0))
+	int32T    = reflect.TypeOf(int32(0))
+	int64T    = reflect.TypeOf(int64(0))
+	addressT  = reflect.TypeOf(common.Address{})
+)
+
+// U256 converts a big Int into a 256bit EVM number.
+func U256(n *big.Int) []byte {
+	return math.PaddedBigBytes(math.U256(n), 32)
+}

accounts/abi/numbers_test.go

@@ -0,0 +1,33 @@
+// Copyright 2015 The go-ethereum Authors
+// This file is part of the go-ethereum library.
+//
+// The go-ethereum library is free software: you can redistribute it and/or modify
+// it under the terms of the GNU Lesser General Public License as published by
+// the Free Software Foundation, either version 3 of the License, or
+// (at your option) any later version.
+//
+// The go-ethereum library is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+// GNU Lesser General Public License for more details.
+//
+// You should have received a copy of the GNU Lesser General Public License
+// along with the go-ethereum library. If not, see <http://www.gnu.org/licenses/>.
+
+package abi
+
+import (
+	"bytes"
+	"math/big"
+	"testing"
+)
+
+func TestNumberTypes(t *testing.T) {
+	ubytes := make([]byte, 32)
+	ubytes[31] = 1
+
+	unsigned := U256(big.NewInt(1))
+	if !bytes.Equal(unsigned, ubytes) {
+		t.Errorf("expected %x got %x", ubytes, unsigned)
+	}
+}

accounts/abi/pack.go

@@ -0,0 +1,81 @@
+// Copyright 2016 The go-ethereum Authors
+// This file is part of the go-ethereum library.
+//
+// The go-ethereum library is free software: you can redistribute it and/or modify
+// it under the terms of the GNU Lesser General Public License as published by
+// the Free Software Foundation, either version 3 of the License, or
+// (at your option) any later version.
+//
+// The go-ethereum library is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+// GNU Lesser General Public License for more details.
+//
+// You should have received a copy of the GNU Lesser General Public License
+// along with the go-ethereum library. If not, see <http://www.gnu.org/licenses/>.
+
+package abi
+
+import (
+	"math/big"
+	"reflect"
+
+	"github.com/ethereum/go-ethereum/common"
+	"github.com/ethereum/go-ethereum/common/math"
+)
+
+// packBytesSlice packs the given bytes as [L, V] as the canonical representation
+// bytes slice
+func packBytesSlice(bytes []byte, l int) []byte {
+	len := packNum(reflect.ValueOf(l))
+	return append(len, common.RightPadBytes(bytes, (l+31)/32*32)...)
+}
+
+// packElement packs the given reflect value according to the abi specification in
+// t.
+func packElement(t Type, reflectValue reflect.Value) []byte {
+	switch t.T {
+	case IntTy, UintTy:
+		return packNum(reflectValue)
+	case StringTy:
+		return packBytesSlice([]byte(reflectValue.String()), reflectValue.Len())
+	case AddressTy:
+		if reflectValue.Kind() == reflect.Array {
+			reflectValue = mustArrayToByteSlice(reflectValue)
+		}
+
+		return common.LeftPadBytes(reflectValue.Bytes(), 32)
+	case BoolTy:
+		if reflectValue.Bool() {
+			return math.PaddedBigBytes(common.Big1, 32)
+		}
+		return math.PaddedBigBytes(common.Big0, 32)
+	case BytesTy:
+		if reflectValue.Kind() == reflect.Array {
+			reflectValue = mustArrayToByteSlice(reflectValue)
+		}
+		return packBytesSlice(reflectValue.Bytes(), reflectValue.Len())
+	case FixedBytesTy, FunctionTy:
+		if reflectValue.Kind() == reflect.Array {
+			reflectValue = mustArrayToByteSlice(reflectValue)
+		}
+		return common.RightPadBytes(reflectValue.Bytes(), 32)
+	default:
+		panic("abi: fatal error")
+	}
+}
+
+// packNum packs the given number (using the reflect value) and will cast it to appropriate number representation
+func packNum(value reflect.Value) []byte {
+	switch kind := value.Kind(); kind {
+	case reflect.Uint, reflect.Uint8, reflect.Uint16, reflect.Uint32, reflect.Uint64:
+		return U256(new(big.Int).SetUint64(value.Uint()))
+	case reflect.Int, reflect.Int8, reflect.Int16, reflect.Int32, reflect.Int64:
+		return U256(big.NewInt(value.Int()))
+	case reflect.Ptr:
+		return U256(value.Interface().(*big.Int))
+	default:
+		panic("abi: fatal error")
+	}
+
+}

accounts/abi/pack_test.go

@@ -0,0 +1,783 @@
+// Copyright 2017 The go-ethereum Authors
+// This file is part of the go-ethereum library.
+//
+// The go-ethereum library is free software: you can redistribute it and/or modify
+// it under the terms of the GNU Lesser General Public License as published by
+// the Free Software Foundation, either version 3 of the License, or
+// (at your option) any later version.
+//
+// The go-ethereum library is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+// GNU Lesser General Public License for more details.
+//
+// You should have received a copy of the GNU Lesser General Public License
+// along with the go-ethereum library. If not, see <http://www.gnu.org/licenses/>.
+
+package abi
+
+import (
+	"bytes"
+	"math"
+	"math/big"
+	"reflect"
+	"strings"
+	"testing"
+
+	"github.com/ethereum/go-ethereum/common"
+)
+
+func TestPack(t *testing.T) {
+	for i, test := range []struct {
+		typ        string
+		components []ArgumentMarshaling
+		input      interface{}
+		output     []byte
+	}{
+		{
+			"uint8",
+			nil,
+			uint8(2),
+			common.Hex2Bytes("0000000000000000000000000000000000000000000000000000000000000002"),
+		},
+		{
+			"uint8[]",
+			nil,
+			[]uint8{1, 2},
+			common.Hex2Bytes("000000000000000000000000000000000000000000000000000000000000000200000000000000000000000000000000000000000000000000000000000000010000000000000000000000000000000000000000000000000000000000000002"),
+		},
+		{
+			"uint16",
+			nil,
+			uint16(2),
+			common.Hex2Bytes("0000000000000000000000000000000000000000000000000000000000000002"),
+		},
+		{
+			"uint16[]",
+			nil,
+			[]uint16{1, 2},
+			common.Hex2Bytes("000000000000000000000000000000000000000000000000000000000000000200000000000000000000000000000000000000000000000000000000000000010000000000000000000000000000000000000000000000000000000000000002"),
+		},
+		{
+			"uint32",
+			nil,
+			uint32(2),
+			common.Hex2Bytes("0000000000000000000000000000000000000000000000000000000000000002"),
+		},
+		{
+			"uint32[]",
+			nil,
+			[]uint32{1, 2},
+			common.Hex2Bytes("000000000000000000000000000000000000000000000000000000000000000200000000000000000000000000000000000000000000000000000000000000010000000000000000000000000000000000000000000000000000000000000002"),
+		},
+		{
+			"uint64",
+			nil,
+			uint64(2),
+			common.Hex2Bytes("0000000000000000000000000000000000000000000000000000000000000002"),
+		},
+		{
+			"uint64[]",
+			nil,
+			[]uint64{1, 2},
+			common.Hex2Bytes("000000000000000000000000000000000000000000000000000000000000000200000000000000000000000000000000000000000000000000000000000000010000000000000000000000000000000000000000000000000000000000000002"),
+		},
+		{
+			"uint256",
+			nil,
+			big.NewInt(2),
+			common.Hex2Bytes("0000000000000000000000000000000000000000000000000000000000000002"),
+		},
+		{
+			"uint256[]",
+			nil,
+			[]*big.Int{big.NewInt(1), big.NewInt(2)},
+			common.Hex2Bytes("000000000000000000000000000000000000000000000000000000000000000200000000000000000000000000000000000000000000000000000000000000010000000000000000000000000000000000000000000000000000000000000002"),
+		},
+		{
+			"int8",
+			nil,
+			int8(2),
+			common.Hex2Bytes("0000000000000000000000000000000000000000000000000000000000000002"),
+		},
+		{
+			"int8[]",
+			nil,
+			[]int8{1, 2},
+			common.Hex2Bytes("000000000000000000000000000000000000000000000000000000000000000200000000000000000000000000000000000000000000000000000000000000010000000000000000000000000000000000000000000000000000000000000002"),
+		},
+		{
+			"int16",
+			nil,
+			int16(2),
+			common.Hex2Bytes("0000000000000000000000000000000000000000000000000000000000000002"),
+		},
+		{
+			"int16[]",
+			nil,
+			[]int16{1, 2},
+			common.Hex2Bytes("000000000000000000000000000000000000000000000000000000000000000200000000000000000000000000000000000000000000000000000000000000010000000000000000000000000000000000000000000000000000000000000002"),
+		},
+		{
+			"int32",
+			nil,
+			int32(2),
+			common.Hex2Bytes("0000000000000000000000000000000000000000000000000000000000000002"),
+		},
+		{
+			"int32[]",
+			nil,
+			[]int32{1, 2},
+			common.Hex2Bytes("000000000000000000000000000000000000000000000000000000000000000200000000000000000000000000000000000000000000000000000000000000010000000000000000000000000000000000000000000000000000000000000002"),
+		},
+		{
+			"int64",
+			nil,
+			int64(2),
+			common.Hex2Bytes("0000000000000000000000000000000000000000000000000000000000000002"),
+		},
+		{
+			"int64[]",
+			nil,
+			[]int64{1, 2},
+			common.Hex2Bytes("000000000000000000000000000000000000000000000000000000000000000200000000000000000000000000000000000000000000000000000000000000010000000000000000000000000000000000000000000000000000000000000002"),
+		},
+		{
+			"int256",
+			nil,
+			big.NewInt(2),
+			common.Hex2Bytes("0000000000000000000000000000000000000000000000000000000000000002"),
+		},
+		{
+			"int256[]",
+			nil,
+			[]*big.Int{big.NewInt(1), big.NewInt(2)},
+			common.Hex2Bytes("000000000000000000000000000000000000000000000000000000000000000200000000000000000000000000000000000000000000000000000000000000010000000000000000000000000000000000000000000000000000000000000002"),
+		},
+		{
+			"bytes1",
+			nil,
+			[1]byte{1},
+			common.Hex2Bytes("0100000000000000000000000000000000000000000000000000000000000000"),
+		},
+		{
+			"bytes2",
+			nil,
+			[2]byte{1},
+			common.Hex2Bytes("0100000000000000000000000000000000000000000000000000000000000000"),
+		},
+		{
+			"bytes3",
+			nil,
+			[3]byte{1},
+			common.Hex2Bytes("0100000000000000000000000000000000000000000000000000000000000000"),
+		},
+		{
+			"bytes4",
+			nil,
+			[4]byte{1},
+			common.Hex2Bytes("0100000000000000000000000000000000000000000000000000000000000000"),
+		},
+		{
+			"bytes5",
+			nil,
+			[5]byte{1},
+			common.Hex2Bytes("0100000000000000000000000000000000000000000000000000000000000000"),
+		},
+		{
+			"bytes6",
+			nil,
+			[6]byte{1},
+			common.Hex2Bytes("0100000000000000000000000000000000000000000000000000000000000000"),
+		},
+		{
+			"bytes7",
+			nil,
+			[7]byte{1},
+			common.Hex2Bytes("0100000000000000000000000000000000000000000000000000000000000000"),
+		},
+		{
+			"bytes8",
+			nil,
+			[8]byte{1},
+			common.Hex2Bytes("0100000000000000000000000000000000000000000000000000000000000000"),
+		},
+		{
+			"bytes9",
+			nil,
+			[9]byte{1},
+			common.Hex2Bytes("0100000000000000000000000000000000000000000000000000000000000000"),
+		},
+		{
+			"bytes10",
+			nil,
+			[10]byte{1},
+			common.Hex2Bytes("0100000000000000000000000000000000000000000000000000000000000000"),
+		},
+		{
+			"bytes11",
+			nil,
+			[11]byte{1},
+			common.Hex2Bytes("0100000000000000000000000000000000000000000000000000000000000000"),
+		},
+		{
+			"bytes12",
+			nil,
+			[12]byte{1},
+			common.Hex2Bytes("0100000000000000000000000000000000000000000000000000000000000000"),
+		},
+		{
+			"bytes13",
+			nil,
+			[13]byte{1},
+			common.Hex2Bytes("0100000000000000000000000000000000000000000000000000000000000000"),
+		},
+		{
+			"bytes14",
+			nil,
+			[14]byte{1},
+			common.Hex2Bytes("0100000000000000000000000000000000000000000000000000000000000000"),
+		},
+		{
+			"bytes15",
+			nil,
+			[15]byte{1},
+			common.Hex2Bytes("0100000000000000000000000000000000000000000000000000000000000000"),
+		},
+		{
+			"bytes16",
+			nil,
+			[16]byte{1},
+			common.Hex2Bytes("0100000000000000000000000000000000000000000000000000000000000000"),
+		},
+		{
+			"bytes17",
+			nil,
+			[17]byte{1},
+			common.Hex2Bytes("0100000000000000000000000000000000000000000000000000000000000000"),
+		},
+		{
+			"bytes18",
+			nil,
+			[18]byte{1},
+			common.Hex2Bytes("0100000000000000000000000000000000000000000000000000000000000000"),
+		},
+		{
+			"bytes19",
+			nil,
+			[19]byte{1},
+			common.Hex2Bytes("0100000000000000000000000000000000000000000000000000000000000000"),
+		},
+		{
+			"bytes20",
+			nil,
+			[20]byte{1},
+			common.Hex2Bytes("0100000000000000000000000000000000000000000000000000000000000000"),
+		},
+		{
+			"bytes21",
+			nil,
+			[21]byte{1},
+			common.Hex2Bytes("0100000000000000000000000000000000000000000000000000000000000000"),
+		},
+		{
+			"bytes22",
+			nil,
+			[22]byte{1},
+			common.Hex2Bytes("0100000000000000000000000000000000000000000000000000000000000000"),
+		},
+		{
+			"bytes23",
+			nil,
+			[23]byte{1},
+			common.Hex2Bytes("0100000000000000000000000000000000000000000000000000000000000000"),
+		},
+		{
+			"bytes24",
+			nil,
+			[24]byte{1},
+			common.Hex2Bytes("0100000000000000000000000000000000000000000000000000000000000000"),
+		},
+		{
+			"bytes25",
+			nil,
+			[25]byte{1},
+			common.Hex2Bytes("0100000000000000000000000000000000000000000000000000000000000000"),
+		},
+		{
+			"bytes26",
+			nil,
+			[26]byte{1},
+			common.Hex2Bytes("0100000000000000000000000000000000000000000000000000000000000000"),
+		},
+		{
+			"bytes27",
+			nil,
+			[27]byte{1},
+			common.Hex2Bytes("0100000000000000000000000000000000000000000000000000000000000000"),
+		},
+		{
+			"bytes28",
+			nil,
+			[28]byte{1},
+			common.Hex2Bytes("0100000000000000000000000000000000000000000000000000000000000000"),
+		},
+		{
+			"bytes29",
+			nil,
+			[29]byte{1},
+			common.Hex2Bytes("0100000000000000000000000000000000000000000000000000000000000000"),
+		},
+		{
+			"bytes30",
+			nil,
+			[30]byte{1},
+			common.Hex2Bytes("0100000000000000000000000000000000000000000000000000000000000000"),
+		},
+		{
+			"bytes31",
+			nil,
+			[31]byte{1},
+			common.Hex2Bytes("0100000000000000000000000000000000000000000000000000000000000000"),
+		},
+		{
+			"bytes32",
+			nil,
+			[32]byte{1},
+			common.Hex2Bytes("0100000000000000000000000000000000000000000000000000000000000000"),
+		},
+		{
+			"uint32[2][3][4]",
+			nil,
+			[4][3][2]uint32{{{1, 2}, {3, 4}, {5, 6}}, {{7, 8}, {9, 10}, {11, 12}}, {{13, 14}, {15, 16}, {17, 18}}, {{19, 20}, {21, 22}, {23, 24}}},
+			common.Hex2Bytes("000000000000000000000000000000000000000000000000000000000000000100000000000000000000000000000000000000000000000000000000000000020000000000000000000000000000000000000000000000000000000000000003000000000000000000000000000000000000000000000000000000000000000400000000000000000000000000000000000000000000000000000000000000050000000000000000000000000000000000000000000000000000000000000006000000000000000000000000000000000000000000000000000000000000000700000000000000000000000000000000000000000000000000000000000000080000000000000000000000000000000000000000000000000000000000000009000000000000000000000000000000000000000000000000000000000000000a000000000000000000000000000000000000000000000000000000000000000b000000000000000000000000000000000000000000000000000000000000000c000000000000000000000000000000000000000000000000000000000000000d000000000000000000000000000000000000000000000000000000000000000e000000000000000000000000000000000000000000000000000000000000000f000000000000000000000000000000000000000000000000000000000000001000000000000000000000000000000000000000000000000000000000000000110000000000000000000000000000000000000000000000000000000000000012000000000000000000000000000000000000000000000000000000000000001300000000000000000000000000000000000000000000000000000000000000140000000000000000000000000000000000000000000000000000000000000015000000000000000000000000000000000000000000000000000000000000001600000000000000000000000000000000000000000000000000000000000000170000000000000000000000000000000000000000000000000000000000000018"),
+		},
+		{
+			"address[]",
+			nil,
+			[]common.Address{{1}, {2}},
+			common.Hex2Bytes("000000000000000000000000000000000000000000000000000000000000000200000000000000000000000001000000000000000000000000000000000000000000000000000000000000000200000000000000000000000000000000000000"),
+		},
+		{
+			"bytes32[]",
+			nil,
+			[]common.Hash{{1}, {2}},
+			common.Hex2Bytes("000000000000000000000000000000000000000000000000000000000000000201000000000000000000000000000000000000000000000000000000000000000200000000000000000000000000000000000000000000000000000000000000"),
+		},
+		{
+			"function",
+			nil,
+			[24]byte{1},
+			common.Hex2Bytes("0100000000000000000000000000000000000000000000000000000000000000"),
+		},
+		{
+			"string",
+			nil,
+			"foobar",
+			common.Hex2Bytes("0000000000000000000000000000000000000000000000000000000000000006666f6f6261720000000000000000000000000000000000000000000000000000"),
+		},
+		{
+			"string[]",
+			nil,
+			[]string{"hello", "foobar"},
+			common.Hex2Bytes("0000000000000000000000000000000000000000000000000000000000000002" + // len(array) = 2
+				"0000000000000000000000000000000000000000000000000000000000000040" + // offset 64 to i = 0
+				"0000000000000000000000000000000000000000000000000000000000000080" + // offset 128 to i = 1
+				"0000000000000000000000000000000000000000000000000000000000000005" + // len(str[0]) = 5
+				"68656c6c6f000000000000000000000000000000000000000000000000000000" + // str[0]
+				"0000000000000000000000000000000000000000000000000000000000000006" + // len(str[1]) = 6
+				"666f6f6261720000000000000000000000000000000000000000000000000000"), // str[1]
+		},
+		{
+			"string[2]",
+			nil,
+			[]string{"hello", "foobar"},
+			common.Hex2Bytes("0000000000000000000000000000000000000000000000000000000000000040" + // offset to i = 0
+				"0000000000000000000000000000000000000000000000000000000000000080" + // offset to i = 1
+				"0000000000000000000000000000000000000000000000000000000000000005" + // len(str[0]) = 5
+				"68656c6c6f000000000000000000000000000000000000000000000000000000" + // str[0]
+				"0000000000000000000000000000000000000000000000000000000000000006" + // len(str[1]) = 6
+				"666f6f6261720000000000000000000000000000000000000000000000000000"), // str[1]
+		},
+		{
+			"bytes32[][]",
+			nil,
+			[][]common.Hash{{{1}, {2}}, {{3}, {4}, {5}}},
+			common.Hex2Bytes("0000000000000000000000000000000000000000000000000000000000000002" + // len(array) = 2
+				"0000000000000000000000000000000000000000000000000000000000000040" + // offset 64 to i = 0
+				"00000000000000000000000000000000000000000000000000000000000000a0" + // offset 160 to i = 1
+				"0000000000000000000000000000000000000000000000000000000000000002" + // len(array[0]) = 2
+				"0100000000000000000000000000000000000000000000000000000000000000" + // array[0][0]
+				"0200000000000000000000000000000000000000000000000000000000000000" + // array[0][1]
+				"0000000000000000000000000000000000000000000000000000000000000003" + // len(array[1]) = 3
+				"0300000000000000000000000000000000000000000000000000000000000000" + // array[1][0]
+				"0400000000000000000000000000000000000000000000000000000000000000" + // array[1][1]
+				"0500000000000000000000000000000000000000000000000000000000000000"), // array[1][2]
+		},
+
+		{
+			"bytes32[][2]",
+			nil,
+			[][]common.Hash{{{1}, {2}}, {{3}, {4}, {5}}},
+			common.Hex2Bytes("0000000000000000000000000000000000000000000000000000000000000040" + // offset 64 to i = 0
+				"00000000000000000000000000000000000000000000000000000000000000a0" + // offset 160 to i = 1
+				"0000000000000000000000000000000000000000000000000000000000000002" + // len(array[0]) = 2
+				"0100000000000000000000000000000000000000000000000000000000000000" + // array[0][0]
+				"0200000000000000000000000000000000000000000000000000000000000000" + // array[0][1]
+				"0000000000000000000000000000000000000000000000000000000000000003" + // len(array[1]) = 3
+				"0300000000000000000000000000000000000000000000000000000000000000" + // array[1][0]
+				"0400000000000000000000000000000000000000000000000000000000000000" + // array[1][1]
+				"0500000000000000000000000000000000000000000000000000000000000000"), // array[1][2]
+		},
+
+		{
+			"bytes32[3][2]",
+			nil,
+			[][]common.Hash{{{1}, {2}, {3}}, {{3}, {4}, {5}}},
+			common.Hex2Bytes("0100000000000000000000000000000000000000000000000000000000000000" + // array[0][0]
+				"0200000000000000000000000000000000000000000000000000000000000000" + // array[0][1]
+				"0300000000000000000000000000000000000000000000000000000000000000" + // array[0][2]
+				"0300000000000000000000000000000000000000000000000000000000000000" + // array[1][0]
+				"0400000000000000000000000000000000000000000000000000000000000000" + // array[1][1]
+				"0500000000000000000000000000000000000000000000000000000000000000"), // array[1][2]
+		},
+		{
+			// static tuple
+			"tuple",
+			[]ArgumentMarshaling{
+				{Name: "a", Type: "int64"},
+				{Name: "b", Type: "int256"},
+				{Name: "c", Type: "int256"},
+				{Name: "d", Type: "bool"},
+				{Name: "e", Type: "bytes32[3][2]"},
+			},
+			struct {
+				A int64
+				B *big.Int
+				C *big.Int
+				D bool
+				E [][]common.Hash
+			}{1, big.NewInt(1), big.NewInt(-1), true, [][]common.Hash{{{1}, {2}, {3}}, {{3}, {4}, {5}}}},
+			common.Hex2Bytes("0000000000000000000000000000000000000000000000000000000000000001" + // struct[a]
+				"0000000000000000000000000000000000000000000000000000000000000001" + // struct[b]
+				"ffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffff" + // struct[c]
+				"0000000000000000000000000000000000000000000000000000000000000001" + // struct[d]
+				"0100000000000000000000000000000000000000000000000000000000000000" + // struct[e] array[0][0]
+				"0200000000000000000000000000000000000000000000000000000000000000" + // struct[e] array[0][1]
+				"0300000000000000000000000000000000000000000000000000000000000000" + // struct[e] array[0][2]
+				"0300000000000000000000000000000000000000000000000000000000000000" + // struct[e] array[1][0]
+				"0400000000000000000000000000000000000000000000000000000000000000" + // struct[e] array[1][1]
+				"0500000000000000000000000000000000000000000000000000000000000000"), // struct[e] array[1][2]
+		},
+		{
+			// dynamic tuple
+			"tuple",
+			[]ArgumentMarshaling{
+				{Name: "a", Type: "string"},
+				{Name: "b", Type: "int64"},
+				{Name: "c", Type: "bytes"},
+				{Name: "d", Type: "string[]"},
+				{Name: "e", Type: "int256[]"},
+				{Name: "f", Type: "address[]"},
+			},
+			struct {
+				FieldA string `abi:"a"` // Test whether abi tag works
+				FieldB int64  `abi:"b"`
+				C      []byte
+				D      []string
+				E      []*big.Int
+				F      []common.Address
+			}{"foobar", 1, []byte{1}, []string{"foo", "bar"}, []*big.Int{big.NewInt(1), big.NewInt(-1)}, []common.Address{{1}, {2}}},
+			common.Hex2Bytes("00000000000000000000000000000000000000000000000000000000000000c0" + // struct[a] offset
+				"0000000000000000000000000000000000000000000000000000000000000001" + // struct[b]
+				"0000000000000000000000000000000000000000000000000000000000000100" + // struct[c] offset
+				"0000000000000000000000000000000000000000000000000000000000000140" + // struct[d] offset
+				"0000000000000000000000000000000000000000000000000000000000000220" + // struct[e] offset
+				"0000000000000000000000000000000000000000000000000000000000000280" + // struct[f] offset
+				"0000000000000000000000000000000000000000000000000000000000000006" + // struct[a] length
+				"666f6f6261720000000000000000000000000000000000000000000000000000" + // struct[a] "foobar"
+				"0000000000000000000000000000000000000000000000000000000000000001" + // struct[c] length
+				"0100000000000000000000000000000000000000000000000000000000000000" + // []byte{1}
+				"0000000000000000000000000000000000000000000000000000000000000002" + // struct[d] length
+				"0000000000000000000000000000000000000000000000000000000000000040" + // foo offset
+				"0000000000000000000000000000000000000000000000000000000000000080" + // bar offset
+				"0000000000000000000000000000000000000000000000000000000000000003" + // foo length
+				"666f6f0000000000000000000000000000000000000000000000000000000000" + // foo
+				"0000000000000000000000000000000000000000000000000000000000000003" + // bar offset
+				"6261720000000000000000000000000000000000000000000000000000000000" + // bar
+				"0000000000000000000000000000000000000000000000000000000000000002" + // struct[e] length
+				"0000000000000000000000000000000000000000000000000000000000000001" + // 1
+				"ffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffff" + // -1
+				"0000000000000000000000000000000000000000000000000000000000000002" + // struct[f] length
+				"0000000000000000000000000100000000000000000000000000000000000000" + // common.Address{1}
+				"0000000000000000000000000200000000000000000000000000000000000000"), // common.Address{2}
+		},
+		{
+			// nested tuple
+			"tuple",
+			[]ArgumentMarshaling{
+				{Name: "a", Type: "tuple", Components: []ArgumentMarshaling{{Name: "a", Type: "uint256"}, {Name: "b", Type: "uint256[]"}}},
+				{Name: "b", Type: "int256[]"},
+			},
+			struct {
+				A struct {
+					FieldA *big.Int `abi:"a"`
+					B      []*big.Int
+				}
+				B []*big.Int
+			}{
+				A: struct {
+					FieldA *big.Int `abi:"a"` // Test whether abi tag works for nested tuple
+					B      []*big.Int
+				}{big.NewInt(1), []*big.Int{big.NewInt(1), big.NewInt(0)}},
+				B: []*big.Int{big.NewInt(1), big.NewInt(0)}},
+			common.Hex2Bytes("0000000000000000000000000000000000000000000000000000000000000040" + // a offset
+				"00000000000000000000000000000000000000000000000000000000000000e0" + // b offset
+				"0000000000000000000000000000000000000000000000000000000000000001" + // a.a value
+				"0000000000000000000000000000000000000000000000000000000000000040" + // a.b offset
+				"0000000000000000000000000000000000000000000000000000000000000002" + // a.b length
+				"0000000000000000000000000000000000000000000000000000000000000001" + // a.b[0] value
+				"0000000000000000000000000000000000000000000000000000000000000000" + // a.b[1] value
+				"0000000000000000000000000000000000000000000000000000000000000002" + // b length
+				"0000000000000000000000000000000000000000000000000000000000000001" + // b[0] value
+				"0000000000000000000000000000000000000000000000000000000000000000"), // b[1] value
+		},
+		{
+			// tuple slice
+			"tuple[]",
+			[]ArgumentMarshaling{
+				{Name: "a", Type: "int256"},
+				{Name: "b", Type: "int256[]"},
+			},
+			[]struct {
+				A *big.Int
+				B []*big.Int
+			}{
+				{big.NewInt(-1), []*big.Int{big.NewInt(1), big.NewInt(0)}},
+				{big.NewInt(1), []*big.Int{big.NewInt(2), big.NewInt(-1)}},
+			},
+			common.Hex2Bytes("0000000000000000000000000000000000000000000000000000000000000002" + // tuple length
+				"0000000000000000000000000000000000000000000000000000000000000040" + // tuple[0] offset
+				"00000000000000000000000000000000000000000000000000000000000000e0" + // tuple[1] offset
+				"ffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffff" + // tuple[0].A
+				"0000000000000000000000000000000000000000000000000000000000000040" + // tuple[0].B offset
+				"0000000000000000000000000000000000000000000000000000000000000002" + // tuple[0].B length
+				"0000000000000000000000000000000000000000000000000000000000000001" + // tuple[0].B[0] value
+				"0000000000000000000000000000000000000000000000000000000000000000" + // tuple[0].B[1] value
+				"0000000000000000000000000000000000000000000000000000000000000001" + // tuple[1].A
+				"0000000000000000000000000000000000000000000000000000000000000040" + // tuple[1].B offset
+				"0000000000000000000000000000000000000000000000000000000000000002" + // tuple[1].B length
+				"0000000000000000000000000000000000000000000000000000000000000002" + // tuple[1].B[0] value
+				"ffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffff"), // tuple[1].B[1] value
+		},
+		{
+			// static tuple array
+			"tuple[2]",
+			[]ArgumentMarshaling{
+				{Name: "a", Type: "int256"},
+				{Name: "b", Type: "int256"},
+			},
+			[2]struct {
+				A *big.Int
+				B *big.Int
+			}{
+				{big.NewInt(-1), big.NewInt(1)},
+				{big.NewInt(1), big.NewInt(-1)},
+			},
+			common.Hex2Bytes("ffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffff" + // tuple[0].a
+				"0000000000000000000000000000000000000000000000000000000000000001" + // tuple[0].b
+				"0000000000000000000000000000000000000000000000000000000000000001" + // tuple[1].a
+				"ffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffff"), // tuple[1].b
+		},
+		{
+			// dynamic tuple array
+			"tuple[2]",
+			[]ArgumentMarshaling{
+				{Name: "a", Type: "int256[]"},
+			},
+			[2]struct {
+				A []*big.Int
+			}{
+				{[]*big.Int{big.NewInt(-1), big.NewInt(1)}},
+				{[]*big.Int{big.NewInt(1), big.NewInt(-1)}},
+			},
+			common.Hex2Bytes("0000000000000000000000000000000000000000000000000000000000000040" + // tuple[0] offset
+				"00000000000000000000000000000000000000000000000000000000000000c0" + // tuple[1] offset
+				"0000000000000000000000000000000000000000000000000000000000000020" + // tuple[0].A offset
+				"0000000000000000000000000000000000000000000000000000000000000002" + // tuple[0].A length
+				"ffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffff" + // tuple[0].A[0]
+				"0000000000000000000000000000000000000000000000000000000000000001" + // tuple[0].A[1]
+				"0000000000000000000000000000000000000000000000000000000000000020" + // tuple[1].A offset
+				"0000000000000000000000000000000000000000000000000000000000000002" + // tuple[1].A length
+				"0000000000000000000000000000000000000000000000000000000000000001" + // tuple[1].A[0]
+				"ffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffff"), // tuple[1].A[1]
+		},
+	} {
+		typ, err := NewType(test.typ, test.components)
+		if err != nil {
+			t.Fatalf("%v failed. Unexpected parse error: %v", i, err)
+		}
+		output, err := typ.pack(reflect.ValueOf(test.input))
+		if err != nil {
+			t.Fatalf("%v failed. Unexpected pack error: %v", i, err)
+		}
+
+		if !bytes.Equal(output, test.output) {
+			t.Errorf("input %d for typ: %v failed. Expected bytes: '%x' Got: '%x'", i, typ.String(), test.output, output)
+		}
+	}
+}
+
+func TestMethodPack(t *testing.T) {
+	abi, err := JSON(strings.NewReader(jsondata2))
+	if err != nil {
+		t.Fatal(err)
+	}
+
+	sig := abi.Methods["slice"].Id()
+	sig = append(sig, common.LeftPadBytes([]byte{1}, 32)...)
+	sig = append(sig, common.LeftPadBytes([]byte{2}, 32)...)
+
+	packed, err := abi.Pack("slice", []uint32{1, 2})
+	if err != nil {
+		t.Error(err)
+	}
+
+	if !bytes.Equal(packed, sig) {
+		t.Errorf("expected %x got %x", sig, packed)
+	}
+
+	var addrA, addrB = common.Address{1}, common.Address{2}
+	sig = abi.Methods["sliceAddress"].Id()
+	sig = append(sig, common.LeftPadBytes([]byte{32}, 32)...)
+	sig = append(sig, common.LeftPadBytes([]byte{2}, 32)...)
+	sig = append(sig, common.LeftPadBytes(addrA[:], 32)...)
+	sig = append(sig, common.LeftPadBytes(addrB[:], 32)...)
+
+	packed, err = abi.Pack("sliceAddress", []common.Address{addrA, addrB})
+	if err != nil {
+		t.Fatal(err)
+	}
+	if !bytes.Equal(packed, sig) {
+		t.Errorf("expected %x got %x", sig, packed)
+	}
+
+	var addrC, addrD = common.Address{3}, common.Address{4}
+	sig = abi.Methods["sliceMultiAddress"].Id()
+	sig = append(sig, common.LeftPadBytes([]byte{64}, 32)...)
+	sig = append(sig, common.LeftPadBytes([]byte{160}, 32)...)
+	sig = append(sig, common.LeftPadBytes([]byte{2}, 32)...)
+	sig = append(sig, common.LeftPadBytes(addrA[:], 32)...)
+	sig = append(sig, common.LeftPadBytes(addrB[:], 32)...)
+	sig = append(sig, common.LeftPadBytes([]byte{2}, 32)...)
+	sig = append(sig, common.LeftPadBytes(addrC[:], 32)...)
+	sig = append(sig, common.LeftPadBytes(addrD[:], 32)...)
+
+	packed, err = abi.Pack("sliceMultiAddress", []common.Address{addrA, addrB}, []common.Address{addrC, addrD})
+	if err != nil {
+		t.Fatal(err)
+	}
+	if !bytes.Equal(packed, sig) {
+		t.Errorf("expected %x got %x", sig, packed)
+	}
+
+	sig = abi.Methods["slice256"].Id()
+	sig = append(sig, common.LeftPadBytes([]byte{1}, 32)...)
+	sig = append(sig, common.LeftPadBytes([]byte{2}, 32)...)
+
+	packed, err = abi.Pack("slice256", []*big.Int{big.NewInt(1), big.NewInt(2)})
+	if err != nil {
+		t.Error(err)
+	}
+
+	if !bytes.Equal(packed, sig) {
+		t.Errorf("expected %x got %x", sig, packed)
+	}
+
+	a := [2][2]*big.Int{{big.NewInt(1), big.NewInt(1)}, {big.NewInt(2), big.NewInt(0)}}
+	sig = abi.Methods["nestedArray"].Id()
+	sig = append(sig, common.LeftPadBytes([]byte{1}, 32)...)
+	sig = append(sig, common.LeftPadBytes([]byte{1}, 32)...)
+	sig = append(sig, common.LeftPadBytes([]byte{2}, 32)...)
+	sig = append(sig, common.LeftPadBytes([]byte{0}, 32)...)
+	sig = append(sig, common.LeftPadBytes([]byte{0xa0}, 32)...)
+	sig = append(sig, common.LeftPadBytes([]byte{2}, 32)...)
+	sig = append(sig, common.LeftPadBytes(addrC[:], 32)...)
+	sig = append(sig, common.LeftPadBytes(addrD[:], 32)...)
+	packed, err = abi.Pack("nestedArray", a, []common.Address{addrC, addrD})
+	if err != nil {
+		t.Fatal(err)
+	}
+	if !bytes.Equal(packed, sig) {
+		t.Errorf("expected %x got %x", sig, packed)
+	}
+
+	sig = abi.Methods["nestedArray2"].Id()
+	sig = append(sig, common.LeftPadBytes([]byte{0x20}, 32)...)
+	sig = append(sig, common.LeftPadBytes([]byte{0x40}, 32)...)
+	sig = append(sig, common.LeftPadBytes([]byte{0x80}, 32)...)
+	sig = append(sig, common.LeftPadBytes([]byte{1}, 32)...)
+	sig = append(sig, common.LeftPadBytes([]byte{1}, 32)...)
+	sig = append(sig, common.LeftPadBytes([]byte{1}, 32)...)
+	sig = append(sig, common.LeftPadBytes([]byte{1}, 32)...)
+	packed, err = abi.Pack("nestedArray2", [2][]uint8{{1}, {1}})
+	if err != nil {
+		t.Fatal(err)
+	}
+	if !bytes.Equal(packed, sig) {
+		t.Errorf("expected %x got %x", sig, packed)
+	}
+
+	sig = abi.Methods["nestedSlice"].Id()
+	sig = append(sig, common.LeftPadBytes([]byte{0x20}, 32)...)
+	sig = append(sig, common.LeftPadBytes([]byte{0x02}, 32)...)
+	sig = append(sig, common.LeftPadBytes([]byte{0x40}, 32)...)
+	sig = append(sig, common.LeftPadBytes([]byte{0xa0}, 32)...)
+	sig = append(sig, common.LeftPadBytes([]byte{2}, 32)...)
+	sig = append(sig, common.LeftPadBytes([]byte{1}, 32)...)
+	sig = append(sig, common.LeftPadBytes([]byte{2}, 32)...)
+	sig = append(sig, common.LeftPadBytes([]byte{2}, 32)...)
+	sig = append(sig, common.LeftPadBytes([]byte{1}, 32)...)
+	sig = append(sig, common.LeftPadBytes([]byte{2}, 32)...)
+	packed, err = abi.Pack("nestedSlice", [][]uint8{{1, 2}, {1, 2}})
+	if err != nil {
+		t.Fatal(err)
+	}
+	if !bytes.Equal(packed, sig) {
+		t.Errorf("expected %x got %x", sig, packed)
+	}
+}
+
+func TestPackNumber(t *testing.T) {
+	tests := []struct {
+		value  reflect.Value
+		packed []byte
+	}{
+		// Protocol limits
+		{reflect.ValueOf(0), common.Hex2Bytes("0000000000000000000000000000000000000000000000000000000000000000")},
+		{reflect.ValueOf(1), common.Hex2Bytes("0000000000000000000000000000000000000000000000000000000000000001")},
+		{reflect.ValueOf(-1), common.Hex2Bytes("ffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffff")},
+
+		// Type corner cases
+		{reflect.ValueOf(uint8(math.MaxUint8)), common.Hex2Bytes("00000000000000000000000000000000000000000000000000000000000000ff")},
+		{reflect.ValueOf(uint16(math.MaxUint16)), common.Hex2Bytes("000000000000000000000000000000000000000000000000000000000000ffff")},
+		{reflect.ValueOf(uint32(math.MaxUint32)), common.Hex2Bytes("00000000000000000000000000000000000000000000000000000000ffffffff")},
+		{reflect.ValueOf(uint64(math.MaxUint64)), common.Hex2Bytes("000000000000000000000000000000000000000000000000ffffffffffffffff")},
+
+		{reflect.ValueOf(int8(math.MaxInt8)), common.Hex2Bytes("000000000000000000000000000000000000000000000000000000000000007f")},
+		{reflect.ValueOf(int16(math.MaxInt16)), common.Hex2Bytes("0000000000000000000000000000000000000000000000000000000000007fff")},
+		{reflect.ValueOf(int32(math.MaxInt32)), common.Hex2Bytes("000000000000000000000000000000000000000000000000000000007fffffff")},
+		{reflect.ValueOf(int64(math.MaxInt64)), common.Hex2Bytes("0000000000000000000000000000000000000000000000007fffffffffffffff")},
+
+		{reflect.ValueOf(int8(math.MinInt8)), common.Hex2Bytes("ffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffff80")},
+		{reflect.ValueOf(int16(math.MinInt16)), common.Hex2Bytes("ffffffffffffffffffffffffffffffffffffffffffffffffffffffffffff8000")},
+		{reflect.ValueOf(int32(math.MinInt32)), common.Hex2Bytes("ffffffffffffffffffffffffffffffffffffffffffffffffffffffff80000000")},
+		{reflect.ValueOf(int64(math.MinInt64)), common.Hex2Bytes("ffffffffffffffffffffffffffffffffffffffffffffffff8000000000000000")},
+	}
+	for i, tt := range tests {
+		packed := packNum(tt.value)
+		if !bytes.Equal(packed, tt.packed) {
+			t.Errorf("test %d: pack mismatch: have %x, want %x", i, packed, tt.packed)
+		}
+	}
+}

accounts/abi/reflect.go

@@ -0,0 +1,218 @@
+// Copyright 2016 The go-ethereum Authors
+// This file is part of the go-ethereum library.
+//
+// The go-ethereum library is free software: you can redistribute it and/or modify
+// it under the terms of the GNU Lesser General Public License as published by
+// the Free Software Foundation, either version 3 of the License, or
+// (at your option) any later version.
+//
+// The go-ethereum library is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+// GNU Lesser General Public License for more details.
+//
+// You should have received a copy of the GNU Lesser General Public License
+// along with the go-ethereum library. If not, see <http://www.gnu.org/licenses/>.
+
+package abi
+
+import (
+	"fmt"
+	"reflect"
+	"strings"
+)
+
+// indirect recursively dereferences the value until it either gets the value
+// or finds a big.Int
+func indirect(v reflect.Value) reflect.Value {
+	if v.Kind() == reflect.Ptr && v.Elem().Type() != derefbigT {
+		return indirect(v.Elem())
+	}
+	return v
+}
+
+// reflectIntKind returns the reflect using the given size and
+// unsignedness.
+func reflectIntKindAndType(unsigned bool, size int) (reflect.Kind, reflect.Type) {
+	switch size {
+	case 8:
+		if unsigned {
+			return reflect.Uint8, uint8T
+		}
+		return reflect.Int8, int8T
+	case 16:
+		if unsigned {
+			return reflect.Uint16, uint16T
+		}
+		return reflect.Int16, int16T
+	case 32:
+		if unsigned {
+			return reflect.Uint32, uint32T
+		}
+		return reflect.Int32, int32T
+	case 64:
+		if unsigned {
+			return reflect.Uint64, uint64T
+		}
+		return reflect.Int64, int64T
+	}
+	return reflect.Ptr, bigT
+}
+
+// mustArrayToBytesSlice creates a new byte slice with the exact same size as value
+// and copies the bytes in value to the new slice.
+func mustArrayToByteSlice(value reflect.Value) reflect.Value {
+	slice := reflect.MakeSlice(reflect.TypeOf([]byte{}), value.Len(), value.Len())
+	reflect.Copy(slice, value)
+	return slice
+}
+
+// set attempts to assign src to dst by either setting, copying or otherwise.
+//
+// set is a bit more lenient when it comes to assignment and doesn't force an as
+// strict ruleset as bare `reflect` does.
+func set(dst, src reflect.Value) error {
+	dstType, srcType := dst.Type(), src.Type()
+	switch {
+	case dstType.Kind() == reflect.Interface && dst.Elem().IsValid():
+		return set(dst.Elem(), src)
+	case dstType.Kind() == reflect.Ptr && dstType.Elem() != derefbigT:
+		return set(dst.Elem(), src)
+	case srcType.AssignableTo(dstType) && dst.CanSet():
+		dst.Set(src)
+	case dstType.Kind() == reflect.Slice && srcType.Kind() == reflect.Slice:
+		return setSlice(dst, src)
+	default:
+		return fmt.Errorf("abi: cannot unmarshal %v in to %v", src.Type(), dst.Type())
+	}
+	return nil
+}
+
+// setSlice attempts to assign src to dst when slices are not assignable by default
+// e.g. src: [][]byte -> dst: [][15]byte
+func setSlice(dst, src reflect.Value) error {
+	slice := reflect.MakeSlice(dst.Type(), src.Len(), src.Len())
+	for i := 0; i < src.Len(); i++ {
+		v := src.Index(i)
+		reflect.Copy(slice.Index(i), v)
+	}
+
+	dst.Set(slice)
+	return nil
+}
+
+// requireAssignable assures that `dest` is a pointer and it's not an interface.
+func requireAssignable(dst, src reflect.Value) error {
+	if dst.Kind() != reflect.Ptr && dst.Kind() != reflect.Interface {
+		return fmt.Errorf("abi: cannot unmarshal %v into %v", src.Type(), dst.Type())
+	}
+	return nil
+}
+
+// requireUnpackKind verifies preconditions for unpacking `args` into `kind`
+func requireUnpackKind(v reflect.Value, t reflect.Type, k reflect.Kind,
+	args Arguments) error {
+
+	switch k {
+	case reflect.Struct:
+	case reflect.Slice, reflect.Array:
+		if minLen := args.LengthNonIndexed(); v.Len() < minLen {
+			return fmt.Errorf("abi: insufficient number of elements in the list/array for unpack, want %d, got %d",
+				minLen, v.Len())
+		}
+	default:
+		return fmt.Errorf("abi: cannot unmarshal tuple into %v", t)
+	}
+	return nil
+}
+
+// mapArgNamesToStructFields maps a slice of argument names to struct fields.
+// first round: for each Exportable field that contains a `abi:""` tag
+//   and this field name exists in the given argument name list, pair them together.
+// second round: for each argument name that has not been already linked,
+//   find what variable is expected to be mapped into, if it exists and has not been
+//   used, pair them.
+// Note this function assumes the given value is a struct value.
+func mapArgNamesToStructFields(argNames []string, value reflect.Value) (map[string]string, error) {
+	typ := value.Type()
+
+	abi2struct := make(map[string]string)
+	struct2abi := make(map[string]string)
+
+	// first round ~~~
+	for i := 0; i < typ.NumField(); i++ {
+		structFieldName := typ.Field(i).Name
+
+		// skip private struct fields.
+		if structFieldName[:1] != strings.ToUpper(structFieldName[:1]) {
+			continue
+		}
+		// skip fields that have no abi:"" tag.
+		var ok bool
+		var tagName string
+		if tagName, ok = typ.Field(i).Tag.Lookup("abi"); !ok {
+			continue
+		}
+		// check if tag is empty.
+		if tagName == "" {
+			return nil, fmt.Errorf("struct: abi tag in '%s' is empty", structFieldName)
+		}
+		// check which argument field matches with the abi tag.
+		found := false
+		for _, arg := range argNames {
+			if arg == tagName {
+				if abi2struct[arg] != "" {
+					return nil, fmt.Errorf("struct: abi tag in '%s' already mapped", structFieldName)
+				}
+				// pair them
+				abi2struct[arg] = structFieldName
+				struct2abi[structFieldName] = arg
+				found = true
+			}
+		}
+		// check if this tag has been mapped.
+		if !found {
+			return nil, fmt.Errorf("struct: abi tag '%s' defined but not found in abi", tagName)
+		}
+	}
+
+	// second round ~~~
+	for _, argName := range argNames {
+
+		structFieldName := ToCamelCase(argName)
+
+		if structFieldName == "" {
+			return nil, fmt.Errorf("abi: purely underscored output cannot unpack to struct")
+		}
+
+		// this abi has already been paired, skip it... unless there exists another, yet unassigned
+		// struct field with the same field name. If so, raise an error:
+		//    abi: [ { "name": "value" } ]
+		//    struct { Value  *big.Int , Value1 *big.Int `abi:"value"`}
+		if abi2struct[argName] != "" {
+			if abi2struct[argName] != structFieldName &&
+				struct2abi[structFieldName] == "" &&
+				value.FieldByName(structFieldName).IsValid() {
+				return nil, fmt.Errorf("abi: multiple variables maps to the same abi field '%s'", argName)
+			}
+			continue
+		}
+
+		// return an error if this struct field has already been paired.
+		if struct2abi[structFieldName] != "" {
+			return nil, fmt.Errorf("abi: multiple outputs mapping to the same struct field '%s'", structFieldName)
+		}
+
+		if value.FieldByName(structFieldName).IsValid() {
+			// pair them
+			abi2struct[argName] = structFieldName
+			struct2abi[structFieldName] = argName
+		} else {
+			// not paired, but annotate as used, to detect cases like
+			//   abi : [ { "name": "value" }, { "name": "_value" } ]
+			//   struct { Value *big.Int }
+			struct2abi[structFieldName] = argName
+		}
+	}
+	return abi2struct, nil
+}

accounts/abi/reflect_test.go

@@ -0,0 +1,191 @@
+// Copyright 2019 The go-ethereum Authors
+// This file is part of the go-ethereum library.
+//
+// The go-ethereum library is free software: you can redistribute it and/or modify
+// it under the terms of the GNU Lesser General Public License as published by
+// the Free Software Foundation, either version 3 of the License, or
+// (at your option) any later version.
+//
+// The go-ethereum library is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+// GNU Lesser General Public License for more details.
+//
+// You should have received a copy of the GNU Lesser General Public License
+// along with the go-ethereum library. If not, see <http://www.gnu.org/licenses/>.
+
+package abi
+
+import (
+	"reflect"
+	"testing"
+)
+
+type reflectTest struct {
+	name  string
+	args  []string
+	struc interface{}
+	want  map[string]string
+	err   string
+}
+
+var reflectTests = []reflectTest{
+	{
+		name: "OneToOneCorrespondance",
+		args: []string{"fieldA"},
+		struc: struct {
+			FieldA int `abi:"fieldA"`
+		}{},
+		want: map[string]string{
+			"fieldA": "FieldA",
+		},
+	},
+	{
+		name: "MissingFieldsInStruct",
+		args: []string{"fieldA", "fieldB"},
+		struc: struct {
+			FieldA int `abi:"fieldA"`
+		}{},
+		want: map[string]string{
+			"fieldA": "FieldA",
+		},
+	},
+	{
+		name: "MoreFieldsInStructThanArgs",
+		args: []string{"fieldA"},
+		struc: struct {
+			FieldA int `abi:"fieldA"`
+			FieldB int
+		}{},
+		want: map[string]string{
+			"fieldA": "FieldA",
+		},
+	},
+	{
+		name: "MissingFieldInArgs",
+		args: []string{"fieldA"},
+		struc: struct {
+			FieldA int `abi:"fieldA"`
+			FieldB int `abi:"fieldB"`
+		}{},
+		err: "struct: abi tag 'fieldB' defined but not found in abi",
+	},
+	{
+		name: "NoAbiDescriptor",
+		args: []string{"fieldA"},
+		struc: struct {
+			FieldA int
+		}{},
+		want: map[string]string{
+			"fieldA": "FieldA",
+		},
+	},
+	{
+		name: "NoArgs",
+		args: []string{},
+		struc: struct {
+			FieldA int `abi:"fieldA"`
+		}{},
+		err: "struct: abi tag 'fieldA' defined but not found in abi",
+	},
+	{
+		name: "DifferentName",
+		args: []string{"fieldB"},
+		struc: struct {
+			FieldA int `abi:"fieldB"`
+		}{},
+		want: map[string]string{
+			"fieldB": "FieldA",
+		},
+	},
+	{
+		name: "DifferentName",
+		args: []string{"fieldB"},
+		struc: struct {
+			FieldA int `abi:"fieldB"`
+		}{},
+		want: map[string]string{
+			"fieldB": "FieldA",
+		},
+	},
+	{
+		name: "MultipleFields",
+		args: []string{"fieldA", "fieldB"},
+		struc: struct {
+			FieldA int `abi:"fieldA"`
+			FieldB int `abi:"fieldB"`
+		}{},
+		want: map[string]string{
+			"fieldA": "FieldA",
+			"fieldB": "FieldB",
+		},
+	},
+	{
+		name: "MultipleFieldsABIMissing",
+		args: []string{"fieldA", "fieldB"},
+		struc: struct {
+			FieldA int `abi:"fieldA"`
+			FieldB int
+		}{},
+		want: map[string]string{
+			"fieldA": "FieldA",
+			"fieldB": "FieldB",
+		},
+	},
+	{
+		name: "NameConflict",
+		args: []string{"fieldB"},
+		struc: struct {
+			FieldA int `abi:"fieldB"`
+			FieldB int
+		}{},
+		err: "abi: multiple variables maps to the same abi field 'fieldB'",
+	},
+	{
+		name: "Underscored",
+		args: []string{"_"},
+		struc: struct {
+			FieldA int
+		}{},
+		err: "abi: purely underscored output cannot unpack to struct",
+	},
+	{
+		name: "DoubleMapping",
+		args: []string{"fieldB", "fieldC", "fieldA"},
+		struc: struct {
+			FieldA int `abi:"fieldC"`
+			FieldB int
+		}{},
+		err: "abi: multiple outputs mapping to the same struct field 'FieldA'",
+	},
+	{
+		name: "AlreadyMapped",
+		args: []string{"fieldB", "fieldB"},
+		struc: struct {
+			FieldB int `abi:"fieldB"`
+		}{},
+		err: "struct: abi tag in 'FieldB' already mapped",
+	},
+}
+
+func TestReflectNameToStruct(t *testing.T) {
+	for _, test := range reflectTests {
+		t.Run(test.name, func(t *testing.T) {
+			m, err := mapArgNamesToStructFields(test.args, reflect.ValueOf(test.struc))
+			if len(test.err) > 0 {
+				if err == nil || err.Error() != test.err {
+					t.Fatalf("Invalid error: expected %v, got %v", test.err, err)
+				}
+			} else {
+				if err != nil {
+					t.Fatalf("Unexpected error: %v", err)
+				}
+				for fname := range test.want {
+					if m[fname] != test.want[fname] {
+						t.Fatalf("Incorrect value for field %s: expected %v, got %v", fname, test.want[fname], m[fname])
+					}
+				}
+			}
+		})
+	}
+}

accounts/abi/type.go

@@ -0,0 +1,353 @@
+// Copyright 2015 The go-ethereum Authors
+// This file is part of the go-ethereum library.
+//
+// The go-ethereum library is free software: you can redistribute it and/or modify
+// it under the terms of the GNU Lesser General Public License as published by
+// the Free Software Foundation, either version 3 of the License, or
+// (at your option) any later version.
+//
+// The go-ethereum library is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+// GNU Lesser General Public License for more details.
+//
+// You should have received a copy of the GNU Lesser General Public License
+// along with the go-ethereum library. If not, see <http://www.gnu.org/licenses/>.
+
+package abi
+
+import (
+	"errors"
+	"fmt"
+	"reflect"
+	"regexp"
+	"strconv"
+	"strings"
+)
+
+// Type enumerator
+const (
+	IntTy byte = iota
+	UintTy
+	BoolTy
+	StringTy
+	SliceTy
+	ArrayTy
+	TupleTy
+	AddressTy
+	FixedBytesTy
+	BytesTy
+	HashTy
+	FixedPointTy
+	FunctionTy
+)
+
+// Type is the reflection of the supported argument type
+type Type struct {
+	Elem *Type
+	Kind reflect.Kind
+	Type reflect.Type
+	Size int
+	T    byte // Our own type checking
+
+	stringKind string // holds the unparsed string for deriving signatures
+
+	// Tuple relative fields
+	TupleElems    []*Type  // Type information of all tuple fields
+	TupleRawNames []string // Raw field name of all tuple fields
+}
+
+var (
+	// typeRegex parses the abi sub types
+	typeRegex = regexp.MustCompile("([a-zA-Z]+)(([0-9]+)(x([0-9]+))?)?")
+)
+
+// NewType creates a new reflection type of abi type given in t.
+func NewType(t string, components []ArgumentMarshaling) (typ Type, err error) {
+	// check that array brackets are equal if they exist
+	if strings.Count(t, "[") != strings.Count(t, "]") {
+		return Type{}, fmt.Errorf("invalid arg type in abi")
+	}
+
+	typ.stringKind = t
+
+	// if there are brackets, get ready to go into slice/array mode and
+	// recursively create the type
+	if strings.Count(t, "[") != 0 {
+		i := strings.LastIndex(t, "[")
+		// recursively embed the type
+		embeddedType, err := NewType(t[:i], components)
+		if err != nil {
+			return Type{}, err
+		}
+		// grab the last cell and create a type from there
+		sliced := t[i:]
+		// grab the slice size with regexp
+		re := regexp.MustCompile("[0-9]+")
+		intz := re.FindAllString(sliced, -1)
+
+		if len(intz) == 0 {
+			// is a slice
+			typ.T = SliceTy
+			typ.Kind = reflect.Slice
+			typ.Elem = &embeddedType
+			typ.Type = reflect.SliceOf(embeddedType.Type)
+			if embeddedType.T == TupleTy {
+				typ.stringKind = embeddedType.stringKind + sliced
+			}
+		} else if len(intz) == 1 {
+			// is a array
+			typ.T = ArrayTy
+			typ.Kind = reflect.Array
+			typ.Elem = &embeddedType
+			typ.Size, err = strconv.Atoi(intz[0])
+			if err != nil {
+				return Type{}, fmt.Errorf("abi: error parsing variable size: %v", err)
+			}
+			typ.Type = reflect.ArrayOf(typ.Size, embeddedType.Type)
+			if embeddedType.T == TupleTy {
+				typ.stringKind = embeddedType.stringKind + sliced
+			}
+		} else {
+			return Type{}, fmt.Errorf("invalid formatting of array type")
+		}
+		return typ, err
+	}
+	// parse the type and size of the abi-type.
+	matches := typeRegex.FindAllStringSubmatch(t, -1)
+	if len(matches) == 0 {
+		return Type{}, fmt.Errorf("invalid type '%v'", t)
+	}
+	parsedType := matches[0]
+
+	// varSize is the size of the variable
+	var varSize int
+	if len(parsedType[3]) > 0 {
+		var err error
+		varSize, err = strconv.Atoi(parsedType[2])
+		if err != nil {
+			return Type{}, fmt.Errorf("abi: error parsing variable size: %v", err)
+		}
+	} else {
+		if parsedType[0] == "uint" || parsedType[0] == "int" {
+			// this should fail because it means that there's something wrong with
+			// the abi type (the compiler should always format it to the size...always)
+			return Type{}, fmt.Errorf("unsupported arg type: %s", t)
+		}
+	}
+	// varType is the parsed abi type
+	switch varType := parsedType[1]; varType {
+	case "int":
+		typ.Kind, typ.Type = reflectIntKindAndType(false, varSize)
+		typ.Size = varSize
+		typ.T = IntTy
+	case "uint":
+		typ.Kind, typ.Type = reflectIntKindAndType(true, varSize)
+		typ.Size = varSize
+		typ.T = UintTy
+	case "bool":
+		typ.Kind = reflect.Bool
+		typ.T = BoolTy
+		typ.Type = reflect.TypeOf(bool(false))
+	case "address":
+		typ.Kind = reflect.Array
+		typ.Type = addressT
+		typ.Size = 20
+		typ.T = AddressTy
+	case "string":
+		typ.Kind = reflect.String
+		typ.Type = reflect.TypeOf("")
+		typ.T = StringTy
+	case "bytes":
+		if varSize == 0 {
+			typ.T = BytesTy
+			typ.Kind = reflect.Slice
+			typ.Type = reflect.SliceOf(reflect.TypeOf(byte(0)))
+		} else {
+			typ.T = FixedBytesTy
+			typ.Kind = reflect.Array
+			typ.Size = varSize
+			typ.Type = reflect.ArrayOf(varSize, reflect.TypeOf(byte(0)))
+		}
+	case "tuple":
+		var (
+			fields     []reflect.StructField
+			elems      []*Type
+			names      []string
+			expression string // canonical parameter expression
+		)
+		expression += "("
+		for idx, c := range components {
+			cType, err := NewType(c.Type, c.Components)
+			if err != nil {
+				return Type{}, err
+			}
+			if ToCamelCase(c.Name) == "" {
+				return Type{}, errors.New("abi: purely anonymous or underscored field is not supported")
+			}
+			fields = append(fields, reflect.StructField{
+				Name: ToCamelCase(c.Name), // reflect.StructOf will panic for any exported field.
+				Type: cType.Type,
+				Tag:  reflect.StructTag("json:\"" + c.Name + "\""),
+			})
+			elems = append(elems, &cType)
+			names = append(names, c.Name)
+			expression += cType.stringKind
+			if idx != len(components)-1 {
+				expression += ","
+			}
+		}
+		expression += ")"
+		typ.Kind = reflect.Struct
+		typ.Type = reflect.StructOf(fields)
+		typ.TupleElems = elems
+		typ.TupleRawNames = names
+		typ.T = TupleTy
+		typ.stringKind = expression
+	case "function":
+		typ.Kind = reflect.Array
+		typ.T = FunctionTy
+		typ.Size = 24
+		typ.Type = reflect.ArrayOf(24, reflect.TypeOf(byte(0)))
+	default:
+		return Type{}, fmt.Errorf("unsupported arg type: %s", t)
+	}
+
+	return
+}
+
+// String implements Stringer
+func (t Type) String() (out string) {
+	return t.stringKind
+}
+
+func (t Type) pack(v reflect.Value) ([]byte, error) {
+	// dereference pointer first if it's a pointer
+	v = indirect(v)
+	if err := typeCheck(t, v); err != nil {
+		return nil, err
+	}
+
+	switch t.T {
+	case SliceTy, ArrayTy:
+		var ret []byte
+
+		if t.requiresLengthPrefix() {
+			// append length
+			ret = append(ret, packNum(reflect.ValueOf(v.Len()))...)
+		}
+
+		// calculate offset if any
+		offset := 0
+		offsetReq := isDynamicType(*t.Elem)
+		if offsetReq {
+			offset = getTypeSize(*t.Elem) * v.Len()
+		}
+		var tail []byte
+		for i := 0; i < v.Len(); i++ {
+			val, err := t.Elem.pack(v.Index(i))
+			if err != nil {
+				return nil, err
+			}
+			if !offsetReq {
+				ret = append(ret, val...)
+				continue
+			}
+			ret = append(ret, packNum(reflect.ValueOf(offset))...)
+			offset += len(val)
+			tail = append(tail, val...)
+		}
+		return append(ret, tail...), nil
+	case TupleTy:
+		// (T1,...,Tk) for k >= 0 and any types T1, …, Tk
+		// enc(X) = head(X(1)) ... head(X(k)) tail(X(1)) ... tail(X(k))
+		// where X = (X(1), ..., X(k)) and head and tail are defined for Ti being a static
+		// type as
+		//     head(X(i)) = enc(X(i)) and tail(X(i)) = "" (the empty string)
+		// and as
+		//     head(X(i)) = enc(len(head(X(1)) ... head(X(k)) tail(X(1)) ... tail(X(i-1))))
+		//     tail(X(i)) = enc(X(i))
+		// otherwise, i.e. if Ti is a dynamic type.
+		fieldmap, err := mapArgNamesToStructFields(t.TupleRawNames, v)
+		if err != nil {
+			return nil, err
+		}
+		// Calculate prefix occupied size.
+		offset := 0
+		for _, elem := range t.TupleElems {
+			offset += getTypeSize(*elem)
+		}
+		var ret, tail []byte
+		for i, elem := range t.TupleElems {
+			field := v.FieldByName(fieldmap[t.TupleRawNames[i]])
+			if !field.IsValid() {
+				return nil, fmt.Errorf("field %s for tuple not found in the given struct", t.TupleRawNames[i])
+			}
+			val, err := elem.pack(field)
+			if err != nil {
+				return nil, err
+			}
+			if isDynamicType(*elem) {
+				ret = append(ret, packNum(reflect.ValueOf(offset))...)
+				tail = append(tail, val...)
+				offset += len(val)
+			} else {
+				ret = append(ret, val...)
+			}
+		}
+		return append(ret, tail...), nil
+
+	default:
+		return packElement(t, v), nil
+	}
+}
+
+// requireLengthPrefix returns whether the type requires any sort of length
+// prefixing.
+func (t Type) requiresLengthPrefix() bool {
+	return t.T == StringTy || t.T == BytesTy || t.T == SliceTy
+}
+
+// isDynamicType returns true if the type is dynamic.
+// The following types are called “dynamic”:
+// * bytes
+// * string
+// * T[] for any T
+// * T[k] for any dynamic T and any k >= 0
+// * (T1,...,Tk) if Ti is dynamic for some 1 <= i <= k
+func isDynamicType(t Type) bool {
+	if t.T == TupleTy {
+		for _, elem := range t.TupleElems {
+			if isDynamicType(*elem) {
+				return true
+			}
+		}
+		return false
+	}
+	return t.T == StringTy || t.T == BytesTy || t.T == SliceTy || (t.T == ArrayTy && isDynamicType(*t.Elem))
+}
+
+// getTypeSize returns the size that this type needs to occupy.
+// We distinguish static and dynamic types. Static types are encoded in-place
+// and dynamic types are encoded at a separately allocated location after the
+// current block.
+// So for a static variable, the size returned represents the size that the
+// variable actually occupies.
+// For a dynamic variable, the returned size is fixed 32 bytes, which is used
+// to store the location reference for actual value storage.
+func getTypeSize(t Type) int {
+	if t.T == ArrayTy && !isDynamicType(*t.Elem) {
+		// Recursively calculate type size if it is a nested array
+		if t.Elem.T == ArrayTy {
+			return t.Size * getTypeSize(*t.Elem)
+		}
+		return t.Size * 32
+	} else if t.T == TupleTy && !isDynamicType(t) {
+		total := 0
+		for _, elem := range t.TupleElems {
+			total += getTypeSize(*elem)
+		}
+		return total
+	}
+	return 32
+}

accounts/abi/type_test.go

@@ -0,0 +1,308 @@
+// Copyright 2016 The go-ethereum Authors
+// This file is part of the go-ethereum library.
+//
+// The go-ethereum library is free software: you can redistribute it and/or modify
+// it under the terms of the GNU Lesser General Public License as published by
+// the Free Software Foundation, either version 3 of the License, or
+// (at your option) any later version.
+//
+// The go-ethereum library is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+// GNU Lesser General Public License for more details.
+//
+// You should have received a copy of the GNU Lesser General Public License
+// along with the go-ethereum library. If not, see <http://www.gnu.org/licenses/>.
+
+package abi
+
+import (
+	"math/big"
+	"reflect"
+	"testing"
+
+	"github.com/davecgh/go-spew/spew"
+	"github.com/ethereum/go-ethereum/common"
+)
+
+// typeWithoutStringer is a alias for the Type type which simply doesn't implement
+// the stringer interface to allow printing type details in the tests below.
+type typeWithoutStringer Type
+
+// Tests that all allowed types get recognized by the type parser.
+func TestTypeRegexp(t *testing.T) {
+	tests := []struct {
+		blob       string
+		components []ArgumentMarshaling
+		kind       Type
+	}{
+		{"bool", nil, Type{Kind: reflect.Bool, T: BoolTy, Type: reflect.TypeOf(bool(false)), stringKind: "bool"}},
+		{"bool[]", nil, Type{Kind: reflect.Slice, T: SliceTy, Type: reflect.TypeOf([]bool(nil)), Elem: &Type{Kind: reflect.Bool, T: BoolTy, Type: reflect.TypeOf(bool(false)), stringKind: "bool"}, stringKind: "bool[]"}},
+		{"bool[2]", nil, Type{Size: 2, Kind: reflect.Array, T: ArrayTy, Type: reflect.TypeOf([2]bool{}), Elem: &Type{Kind: reflect.Bool, T: BoolTy, Type: reflect.TypeOf(bool(false)), stringKind: "bool"}, stringKind: "bool[2]"}},
+		{"bool[2][]", nil, Type{Kind: reflect.Slice, T: SliceTy, Type: reflect.TypeOf([][2]bool{}), Elem: &Type{Kind: reflect.Array, T: ArrayTy, Size: 2, Type: reflect.TypeOf([2]bool{}), Elem: &Type{Kind: reflect.Bool, T: BoolTy, Type: reflect.TypeOf(bool(false)), stringKind: "bool"}, stringKind: "bool[2]"}, stringKind: "bool[2][]"}},
+		{"bool[][]", nil, Type{Kind: reflect.Slice, T: SliceTy, Type: reflect.TypeOf([][]bool{}), Elem: &Type{Kind: reflect.Slice, T: SliceTy, Type: reflect.TypeOf([]bool{}), Elem: &Type{Kind: reflect.Bool, T: BoolTy, Type: reflect.TypeOf(bool(false)), stringKind: "bool"}, stringKind: "bool[]"}, stringKind: "bool[][]"}},
+		{"bool[][2]", nil, Type{Kind: reflect.Array, T: ArrayTy, Size: 2, Type: reflect.TypeOf([2][]bool{}), Elem: &Type{Kind: reflect.Slice, T: SliceTy, Type: reflect.TypeOf([]bool{}), Elem: &Type{Kind: reflect.Bool, T: BoolTy, Type: reflect.TypeOf(bool(false)), stringKind: "bool"}, stringKind: "bool[]"}, stringKind: "bool[][2]"}},
+		{"bool[2][2]", nil, Type{Kind: reflect.Array, T: ArrayTy, Size: 2, Type: reflect.TypeOf([2][2]bool{}), Elem: &Type{Kind: reflect.Array, T: ArrayTy, Size: 2, Type: reflect.TypeOf([2]bool{}), Elem: &Type{Kind: reflect.Bool, T: BoolTy, Type: reflect.TypeOf(bool(false)), stringKind: "bool"}, stringKind: "bool[2]"}, stringKind: "bool[2][2]"}},
+		{"bool[2][][2]", nil, Type{Kind: reflect.Array, T: ArrayTy, Size: 2, Type: reflect.TypeOf([2][][2]bool{}), Elem: &Type{Kind: reflect.Slice, T: SliceTy, Type: reflect.TypeOf([][2]bool{}), Elem: &Type{Kind: reflect.Array, T: ArrayTy, Size: 2, Type: reflect.TypeOf([2]bool{}), Elem: &Type{Kind: reflect.Bool, T: BoolTy, Type: reflect.TypeOf(bool(false)), stringKind: "bool"}, stringKind: "bool[2]"}, stringKind: "bool[2][]"}, stringKind: "bool[2][][2]"}},
+		{"bool[2][2][2]", nil, Type{Kind: reflect.Array, T: ArrayTy, Size: 2, Type: reflect.TypeOf([2][2][2]bool{}), Elem: &Type{Kind: reflect.Array, T: ArrayTy, Size: 2, Type: reflect.TypeOf([2][2]bool{}), Elem: &Type{Kind: reflect.Array, T: ArrayTy, Size: 2, Type: reflect.TypeOf([2]bool{}), Elem: &Type{Kind: reflect.Bool, T: BoolTy, Type: reflect.TypeOf(bool(false)), stringKind: "bool"}, stringKind: "bool[2]"}, stringKind: "bool[2][2]"}, stringKind: "bool[2][2][2]"}},
+		{"bool[][][]", nil, Type{T: SliceTy, Kind: reflect.Slice, Type: reflect.TypeOf([][][]bool{}), Elem: &Type{T: SliceTy, Kind: reflect.Slice, Type: reflect.TypeOf([][]bool{}), Elem: &Type{T: SliceTy, Kind: reflect.Slice, Type: reflect.TypeOf([]bool{}), Elem: &Type{Kind: reflect.Bool, T: BoolTy, Type: reflect.TypeOf(bool(false)), stringKind: "bool"}, stringKind: "bool[]"}, stringKind: "bool[][]"}, stringKind: "bool[][][]"}},
+		{"bool[][2][]", nil, Type{T: SliceTy, Kind: reflect.Slice, Type: reflect.TypeOf([][2][]bool{}), Elem: &Type{Kind: reflect.Array, T: ArrayTy, Size: 2, Type: reflect.TypeOf([2][]bool{}), Elem: &Type{T: SliceTy, Kind: reflect.Slice, Type: reflect.TypeOf([]bool{}), Elem: &Type{Kind: reflect.Bool, T: BoolTy, Type: reflect.TypeOf(bool(false)), stringKind: "bool"}, stringKind: "bool[]"}, stringKind: "bool[][2]"}, stringKind: "bool[][2][]"}},
+		{"int8", nil, Type{Kind: reflect.Int8, Type: int8T, Size: 8, T: IntTy, stringKind: "int8"}},
+		{"int16", nil, Type{Kind: reflect.Int16, Type: int16T, Size: 16, T: IntTy, stringKind: "int16"}},
+		{"int32", nil, Type{Kind: reflect.Int32, Type: int32T, Size: 32, T: IntTy, stringKind: "int32"}},
+		{"int64", nil, Type{Kind: reflect.Int64, Type: int64T, Size: 64, T: IntTy, stringKind: "int64"}},
+		{"int256", nil, Type{Kind: reflect.Ptr, Type: bigT, Size: 256, T: IntTy, stringKind: "int256"}},
+		{"int8[]", nil, Type{Kind: reflect.Slice, T: SliceTy, Type: reflect.TypeOf([]int8{}), Elem: &Type{Kind: reflect.Int8, Type: int8T, Size: 8, T: IntTy, stringKind: "int8"}, stringKind: "int8[]"}},
+		{"int8[2]", nil, Type{Kind: reflect.Array, T: ArrayTy, Size: 2, Type: reflect.TypeOf([2]int8{}), Elem: &Type{Kind: reflect.Int8, Type: int8T, Size: 8, T: IntTy, stringKind: "int8"}, stringKind: "int8[2]"}},
+		{"int16[]", nil, Type{Kind: reflect.Slice, T: SliceTy, Type: reflect.TypeOf([]int16{}), Elem: &Type{Kind: reflect.Int16, Type: int16T, Size: 16, T: IntTy, stringKind: "int16"}, stringKind: "int16[]"}},
+		{"int16[2]", nil, Type{Size: 2, Kind: reflect.Array, T: ArrayTy, Type: reflect.TypeOf([2]int16{}), Elem: &Type{Kind: reflect.Int16, Type: int16T, Size: 16, T: IntTy, stringKind: "int16"}, stringKind: "int16[2]"}},
+		{"int32[]", nil, Type{Kind: reflect.Slice, T: SliceTy, Type: reflect.TypeOf([]int32{}), Elem: &Type{Kind: reflect.Int32, Type: int32T, Size: 32, T: IntTy, stringKind: "int32"}, stringKind: "int32[]"}},
+		{"int32[2]", nil, Type{Kind: reflect.Array, T: ArrayTy, Size: 2, Type: reflect.TypeOf([2]int32{}), Elem: &Type{Kind: reflect.Int32, Type: int32T, Size: 32, T: IntTy, stringKind: "int32"}, stringKind: "int32[2]"}},
+		{"int64[]", nil, Type{Kind: reflect.Slice, T: SliceTy, Type: reflect.TypeOf([]int64{}), Elem: &Type{Kind: reflect.Int64, Type: int64T, Size: 64, T: IntTy, stringKind: "int64"}, stringKind: "int64[]"}},
+		{"int64[2]", nil, Type{Kind: reflect.Array, T: ArrayTy, Size: 2, Type: reflect.TypeOf([2]int64{}), Elem: &Type{Kind: reflect.Int64, Type: int64T, Size: 64, T: IntTy, stringKind: "int64"}, stringKind: "int64[2]"}},
+		{"int256[]", nil, Type{Kind: reflect.Slice, T: SliceTy, Type: reflect.TypeOf([]*big.Int{}), Elem: &Type{Kind: reflect.Ptr, Type: bigT, Size: 256, T: IntTy, stringKind: "int256"}, stringKind: "int256[]"}},
+		{"int256[2]", nil, Type{Kind: reflect.Array, T: ArrayTy, Size: 2, Type: reflect.TypeOf([2]*big.Int{}), Elem: &Type{Kind: reflect.Ptr, Type: bigT, Size: 256, T: IntTy, stringKind: "int256"}, stringKind: "int256[2]"}},
+		{"uint8", nil, Type{Kind: reflect.Uint8, Type: uint8T, Size: 8, T: UintTy, stringKind: "uint8"}},
+		{"uint16", nil, Type{Kind: reflect.Uint16, Type: uint16T, Size: 16, T: UintTy, stringKind: "uint16"}},
+		{"uint32", nil, Type{Kind: reflect.Uint32, Type: uint32T, Size: 32, T: UintTy, stringKind: "uint32"}},
+		{"uint64", nil, Type{Kind: reflect.Uint64, Type: uint64T, Size: 64, T: UintTy, stringKind: "uint64"}},
+		{"uint256", nil, Type{Kind: reflect.Ptr, Type: bigT, Size: 256, T: UintTy, stringKind: "uint256"}},
+		{"uint8[]", nil, Type{Kind: reflect.Slice, T: SliceTy, Type: reflect.TypeOf([]uint8{}), Elem: &Type{Kind: reflect.Uint8, Type: uint8T, Size: 8, T: UintTy, stringKind: "uint8"}, stringKind: "uint8[]"}},
+		{"uint8[2]", nil, Type{Kind: reflect.Array, T: ArrayTy, Size: 2, Type: reflect.TypeOf([2]uint8{}), Elem: &Type{Kind: reflect.Uint8, Type: uint8T, Size: 8, T: UintTy, stringKind: "uint8"}, stringKind: "uint8[2]"}},
+		{"uint16[]", nil, Type{T: SliceTy, Kind: reflect.Slice, Type: reflect.TypeOf([]uint16{}), Elem: &Type{Kind: reflect.Uint16, Type: uint16T, Size: 16, T: UintTy, stringKind: "uint16"}, stringKind: "uint16[]"}},
+		{"uint16[2]", nil, Type{Kind: reflect.Array, T: ArrayTy, Size: 2, Type: reflect.TypeOf([2]uint16{}), Elem: &Type{Kind: reflect.Uint16, Type: uint16T, Size: 16, T: UintTy, stringKind: "uint16"}, stringKind: "uint16[2]"}},
+		{"uint32[]", nil, Type{T: SliceTy, Kind: reflect.Slice, Type: reflect.TypeOf([]uint32{}), Elem: &Type{Kind: reflect.Uint32, Type: uint32T, Size: 32, T: UintTy, stringKind: "uint32"}, stringKind: "uint32[]"}},
+		{"uint32[2]", nil, Type{Kind: reflect.Array, T: ArrayTy, Size: 2, Type: reflect.TypeOf([2]uint32{}), Elem: &Type{Kind: reflect.Uint32, Type: uint32T, Size: 32, T: UintTy, stringKind: "uint32"}, stringKind: "uint32[2]"}},
+		{"uint64[]", nil, Type{T: SliceTy, Kind: reflect.Slice, Type: reflect.TypeOf([]uint64{}), Elem: &Type{Kind: reflect.Uint64, Type: uint64T, Size: 64, T: UintTy, stringKind: "uint64"}, stringKind: "uint64[]"}},
+		{"uint64[2]", nil, Type{Kind: reflect.Array, T: ArrayTy, Size: 2, Type: reflect.TypeOf([2]uint64{}), Elem: &Type{Kind: reflect.Uint64, Type: uint64T, Size: 64, T: UintTy, stringKind: "uint64"}, stringKind: "uint64[2]"}},
+		{"uint256[]", nil, Type{T: SliceTy, Kind: reflect.Slice, Type: reflect.TypeOf([]*big.Int{}), Elem: &Type{Kind: reflect.Ptr, Type: bigT, Size: 256, T: UintTy, stringKind: "uint256"}, stringKind: "uint256[]"}},
+		{"uint256[2]", nil, Type{Kind: reflect.Array, T: ArrayTy, Type: reflect.TypeOf([2]*big.Int{}), Size: 2, Elem: &Type{Kind: reflect.Ptr, Type: bigT, Size: 256, T: UintTy, stringKind: "uint256"}, stringKind: "uint256[2]"}},
+		{"bytes32", nil, Type{Kind: reflect.Array, T: FixedBytesTy, Size: 32, Type: reflect.TypeOf([32]byte{}), stringKind: "bytes32"}},
+		{"bytes[]", nil, Type{T: SliceTy, Kind: reflect.Slice, Type: reflect.TypeOf([][]byte{}), Elem: &Type{Kind: reflect.Slice, Type: reflect.TypeOf([]byte{}), T: BytesTy, stringKind: "bytes"}, stringKind: "bytes[]"}},
+		{"bytes[2]", nil, Type{Kind: reflect.Array, T: ArrayTy, Size: 2, Type: reflect.TypeOf([2][]byte{}), Elem: &Type{T: BytesTy, Type: reflect.TypeOf([]byte{}), Kind: reflect.Slice, stringKind: "bytes"}, stringKind: "bytes[2]"}},
+		{"bytes32[]", nil, Type{T: SliceTy, Kind: reflect.Slice, Type: reflect.TypeOf([][32]byte{}), Elem: &Type{Kind: reflect.Array, Type: reflect.TypeOf([32]byte{}), T: FixedBytesTy, Size: 32, stringKind: "bytes32"}, stringKind: "bytes32[]"}},
+		{"bytes32[2]", nil, Type{Kind: reflect.Array, T: ArrayTy, Size: 2, Type: reflect.TypeOf([2][32]byte{}), Elem: &Type{Kind: reflect.Array, T: FixedBytesTy, Size: 32, Type: reflect.TypeOf([32]byte{}), stringKind: "bytes32"}, stringKind: "bytes32[2]"}},
+		{"string", nil, Type{Kind: reflect.String, T: StringTy, Type: reflect.TypeOf(""), stringKind: "string"}},
+		{"string[]", nil, Type{T: SliceTy, Kind: reflect.Slice, Type: reflect.TypeOf([]string{}), Elem: &Type{Kind: reflect.String, Type: reflect.TypeOf(""), T: StringTy, stringKind: "string"}, stringKind: "string[]"}},
+		{"string[2]", nil, Type{Kind: reflect.Array, T: ArrayTy, Size: 2, Type: reflect.TypeOf([2]string{}), Elem: &Type{Kind: reflect.String, T: StringTy, Type: reflect.TypeOf(""), stringKind: "string"}, stringKind: "string[2]"}},
+		{"address", nil, Type{Kind: reflect.Array, Type: addressT, Size: 20, T: AddressTy, stringKind: "address"}},
+		{"address[]", nil, Type{T: SliceTy, Kind: reflect.Slice, Type: reflect.TypeOf([]common.Address{}), Elem: &Type{Kind: reflect.Array, Type: addressT, Size: 20, T: AddressTy, stringKind: "address"}, stringKind: "address[]"}},
+		{"address[2]", nil, Type{Kind: reflect.Array, T: ArrayTy, Size: 2, Type: reflect.TypeOf([2]common.Address{}), Elem: &Type{Kind: reflect.Array, Type: addressT, Size: 20, T: AddressTy, stringKind: "address"}, stringKind: "address[2]"}},
+		// TODO when fixed types are implemented properly
+		// {"fixed", nil, Type{}},
+		// {"fixed128x128", nil, Type{}},
+		// {"fixed[]", nil, Type{}},
+		// {"fixed[2]", nil, Type{}},
+		// {"fixed128x128[]", nil, Type{}},
+		// {"fixed128x128[2]", nil, Type{}},
+		{"tuple", []ArgumentMarshaling{{Name: "a", Type: "int64"}}, Type{Kind: reflect.Struct, T: TupleTy, Type: reflect.TypeOf(struct {
+			A int64 `json:"a"`
+		}{}), stringKind: "(int64)",
+			TupleElems: []*Type{{Kind: reflect.Int64, T: IntTy, Type: reflect.TypeOf(int64(0)), Size: 64, stringKind: "int64"}}, TupleRawNames: []string{"a"}}},
+		{"tuple with long name", []ArgumentMarshaling{{Name: "aTypicalParamName", Type: "int64"}}, Type{Kind: reflect.Struct, T: TupleTy, Type: reflect.TypeOf(struct {
+			ATypicalParamName int64 `json:"aTypicalParamName"`
+		}{}), stringKind: "(int64)",
+			TupleElems: []*Type{{Kind: reflect.Int64, T: IntTy, Type: reflect.TypeOf(int64(0)), Size: 64, stringKind: "int64"}}, TupleRawNames: []string{"aTypicalParamName"}}},
+	}
+
+	for _, tt := range tests {
+		typ, err := NewType(tt.blob, tt.components)
+		if err != nil {
+			t.Errorf("type %q: failed to parse type string: %v", tt.blob, err)
+		}
+		if !reflect.DeepEqual(typ, tt.kind) {
+			t.Errorf("type %q: parsed type mismatch:\nGOT %s\nWANT %s ", tt.blob, spew.Sdump(typeWithoutStringer(typ)), spew.Sdump(typeWithoutStringer(tt.kind)))
+		}
+	}
+}
+
+func TestTypeCheck(t *testing.T) {
+	for i, test := range []struct {
+		typ        string
+		components []ArgumentMarshaling
+		input      interface{}
+		err        string
+	}{
+		{"uint", nil, big.NewInt(1), "unsupported arg type: uint"},
+		{"int", nil, big.NewInt(1), "unsupported arg type: int"},
+		{"uint256", nil, big.NewInt(1), ""},
+		{"uint256[][3][]", nil, [][3][]*big.Int{{{}}}, ""},
+		{"uint256[][][3]", nil, [3][][]*big.Int{{{}}}, ""},
+		{"uint256[3][][]", nil, [][][3]*big.Int{{{}}}, ""},
+		{"uint256[3][3][3]", nil, [3][3][3]*big.Int{{{}}}, ""},
+		{"uint8[][]", nil, [][]uint8{}, ""},
+		{"int256", nil, big.NewInt(1), ""},
+		{"uint8", nil, uint8(1), ""},
+		{"uint16", nil, uint16(1), ""},
+		{"uint32", nil, uint32(1), ""},
+		{"uint64", nil, uint64(1), ""},
+		{"int8", nil, int8(1), ""},
+		{"int16", nil, int16(1), ""},
+		{"int32", nil, int32(1), ""},
+		{"int64", nil, int64(1), ""},
+		{"uint24", nil, big.NewInt(1), ""},
+		{"uint40", nil, big.NewInt(1), ""},
+		{"uint48", nil, big.NewInt(1), ""},
+		{"uint56", nil, big.NewInt(1), ""},
+		{"uint72", nil, big.NewInt(1), ""},
+		{"uint80", nil, big.NewInt(1), ""},
+		{"uint88", nil, big.NewInt(1), ""},
+		{"uint96", nil, big.NewInt(1), ""},
+		{"uint104", nil, big.NewInt(1), ""},
+		{"uint112", nil, big.NewInt(1), ""},
+		{"uint120", nil, big.NewInt(1), ""},
+		{"uint128", nil, big.NewInt(1), ""},
+		{"uint136", nil, big.NewInt(1), ""},
+		{"uint144", nil, big.NewInt(1), ""},
+		{"uint152", nil, big.NewInt(1), ""},
+		{"uint160", nil, big.NewInt(1), ""},
+		{"uint168", nil, big.NewInt(1), ""},
+		{"uint176", nil, big.NewInt(1), ""},
+		{"uint184", nil, big.NewInt(1), ""},
+		{"uint192", nil, big.NewInt(1), ""},
+		{"uint200", nil, big.NewInt(1), ""},
+		{"uint208", nil, big.NewInt(1), ""},
+		{"uint216", nil, big.NewInt(1), ""},
+		{"uint224", nil, big.NewInt(1), ""},
+		{"uint232", nil, big.NewInt(1), ""},
+		{"uint240", nil, big.NewInt(1), ""},
+		{"uint248", nil, big.NewInt(1), ""},
+		{"int24", nil, big.NewInt(1), ""},
+		{"int40", nil, big.NewInt(1), ""},
+		{"int48", nil, big.NewInt(1), ""},
+		{"int56", nil, big.NewInt(1), ""},
+		{"int72", nil, big.NewInt(1), ""},
+		{"int80", nil, big.NewInt(1), ""},
+		{"int88", nil, big.NewInt(1), ""},
+		{"int96", nil, big.NewInt(1), ""},
+		{"int104", nil, big.NewInt(1), ""},
+		{"int112", nil, big.NewInt(1), ""},
+		{"int120", nil, big.NewInt(1), ""},
+		{"int128", nil, big.NewInt(1), ""},
+		{"int136", nil, big.NewInt(1), ""},
+		{"int144", nil, big.NewInt(1), ""},
+		{"int152", nil, big.NewInt(1), ""},
+		{"int160", nil, big.NewInt(1), ""},
+		{"int168", nil, big.NewInt(1), ""},
+		{"int176", nil, big.NewInt(1), ""},
+		{"int184", nil, big.NewInt(1), ""},
+		{"int192", nil, big.NewInt(1), ""},
+		{"int200", nil, big.NewInt(1), ""},
+		{"int208", nil, big.NewInt(1), ""},
+		{"int216", nil, big.NewInt(1), ""},
+		{"int224", nil, big.NewInt(1), ""},
+		{"int232", nil, big.NewInt(1), ""},
+		{"int240", nil, big.NewInt(1), ""},
+		{"int248", nil, big.NewInt(1), ""},
+		{"uint30", nil, uint8(1), "abi: cannot use uint8 as type ptr as argument"},
+		{"uint8", nil, uint16(1), "abi: cannot use uint16 as type uint8 as argument"},
+		{"uint8", nil, uint32(1), "abi: cannot use uint32 as type uint8 as argument"},
+		{"uint8", nil, uint64(1), "abi: cannot use uint64 as type uint8 as argument"},
+		{"uint8", nil, int8(1), "abi: cannot use int8 as type uint8 as argument"},
+		{"uint8", nil, int16(1), "abi: cannot use int16 as type uint8 as argument"},
+		{"uint8", nil, int32(1), "abi: cannot use int32 as type uint8 as argument"},
+		{"uint8", nil, int64(1), "abi: cannot use int64 as type uint8 as argument"},
+		{"uint16", nil, uint16(1), ""},
+		{"uint16", nil, uint8(1), "abi: cannot use uint8 as type uint16 as argument"},
+		{"uint16[]", nil, []uint16{1, 2, 3}, ""},
+		{"uint16[]", nil, [3]uint16{1, 2, 3}, ""},
+		{"uint16[]", nil, []uint32{1, 2, 3}, "abi: cannot use []uint32 as type [0]uint16 as argument"},
+		{"uint16[3]", nil, [3]uint32{1, 2, 3}, "abi: cannot use [3]uint32 as type [3]uint16 as argument"},
+		{"uint16[3]", nil, [4]uint16{1, 2, 3}, "abi: cannot use [4]uint16 as type [3]uint16 as argument"},
+		{"uint16[3]", nil, []uint16{1, 2, 3}, ""},
+		{"uint16[3]", nil, []uint16{1, 2, 3, 4}, "abi: cannot use [4]uint16 as type [3]uint16 as argument"},
+		{"address[]", nil, []common.Address{{1}}, ""},
+		{"address[1]", nil, []common.Address{{1}}, ""},
+		{"address[1]", nil, [1]common.Address{{1}}, ""},
+		{"address[2]", nil, [1]common.Address{{1}}, "abi: cannot use [1]array as type [2]array as argument"},
+		{"bytes32", nil, [32]byte{}, ""},
+		{"bytes31", nil, [31]byte{}, ""},
+		{"bytes30", nil, [30]byte{}, ""},
+		{"bytes29", nil, [29]byte{}, ""},
+		{"bytes28", nil, [28]byte{}, ""},
+		{"bytes27", nil, [27]byte{}, ""},
+		{"bytes26", nil, [26]byte{}, ""},
+		{"bytes25", nil, [25]byte{}, ""},
+		{"bytes24", nil, [24]byte{}, ""},
+		{"bytes23", nil, [23]byte{}, ""},
+		{"bytes22", nil, [22]byte{}, ""},
+		{"bytes21", nil, [21]byte{}, ""},
+		{"bytes20", nil, [20]byte{}, ""},
+		{"bytes19", nil, [19]byte{}, ""},
+		{"bytes18", nil, [18]byte{}, ""},
+		{"bytes17", nil, [17]byte{}, ""},
+		{"bytes16", nil, [16]byte{}, ""},
+		{"bytes15", nil, [15]byte{}, ""},
+		{"bytes14", nil, [14]byte{}, ""},
+		{"bytes13", nil, [13]byte{}, ""},
+		{"bytes12", nil, [12]byte{}, ""},
+		{"bytes11", nil, [11]byte{}, ""},
+		{"bytes10", nil, [10]byte{}, ""},
+		{"bytes9", nil, [9]byte{}, ""},
+		{"bytes8", nil, [8]byte{}, ""},
+		{"bytes7", nil, [7]byte{}, ""},
+		{"bytes6", nil, [6]byte{}, ""},
+		{"bytes5", nil, [5]byte{}, ""},
+		{"bytes4", nil, [4]byte{}, ""},
+		{"bytes3", nil, [3]byte{}, ""},
+		{"bytes2", nil, [2]byte{}, ""},
+		{"bytes1", nil, [1]byte{}, ""},
+		{"bytes32", nil, [33]byte{}, "abi: cannot use [33]uint8 as type [32]uint8 as argument"},
+		{"bytes32", nil, common.Hash{1}, ""},
+		{"bytes31", nil, common.Hash{1}, "abi: cannot use common.Hash as type [31]uint8 as argument"},
+		{"bytes31", nil, [32]byte{}, "abi: cannot use [32]uint8 as type [31]uint8 as argument"},
+		{"bytes", nil, []byte{0, 1}, ""},
+		{"bytes", nil, [2]byte{0, 1}, "abi: cannot use array as type slice as argument"},
+		{"bytes", nil, common.Hash{1}, "abi: cannot use array as type slice as argument"},
+		{"string", nil, "hello world", ""},
+		{"string", nil, string(""), ""},
+		{"string", nil, []byte{}, "abi: cannot use slice as type string as argument"},
+		{"bytes32[]", nil, [][32]byte{{}}, ""},
+		{"function", nil, [24]byte{}, ""},
+		{"bytes20", nil, common.Address{}, ""},
+		{"address", nil, [20]byte{}, ""},
+		{"address", nil, common.Address{}, ""},
+		{"bytes32[]]", nil, "", "invalid arg type in abi"},
+		{"invalidType", nil, "", "unsupported arg type: invalidType"},
+		{"invalidSlice[]", nil, "", "unsupported arg type: invalidSlice"},
+		// simple tuple
+		{"tuple", []ArgumentMarshaling{{Name: "a", Type: "uint256"}, {Name: "b", Type: "uint256"}}, struct {
+			A *big.Int
+			B *big.Int
+		}{}, ""},
+		// tuple slice
+		{"tuple[]", []ArgumentMarshaling{{Name: "a", Type: "uint256"}, {Name: "b", Type: "uint256"}}, []struct {
+			A *big.Int
+			B *big.Int
+		}{}, ""},
+		// tuple array
+		{"tuple[2]", []ArgumentMarshaling{{Name: "a", Type: "uint256"}, {Name: "b", Type: "uint256"}}, []struct {
+			A *big.Int
+			B *big.Int
+		}{{big.NewInt(0), big.NewInt(0)}, {big.NewInt(0), big.NewInt(0)}}, ""},
+	} {
+		typ, err := NewType(test.typ, test.components)
+		if err != nil && len(test.err) == 0 {
+			t.Fatal("unexpected parse error:", err)
+		} else if err != nil && len(test.err) != 0 {
+			if err.Error() != test.err {
+				t.Errorf("%d failed. Expected err: '%v' got err: '%v'", i, test.err, err)
+			}
+			continue
+		}
+
+		err = typeCheck(typ, reflect.ValueOf(test.input))
+		if err != nil && len(test.err) == 0 {
+			t.Errorf("%d failed. Expected no err but got: %v", i, err)
+			continue
+		}
+		if err == nil && len(test.err) != 0 {
+			t.Errorf("%d failed. Expected err: %v but got none", i, test.err)
+			continue
+		}
+
+		if err != nil && len(test.err) != 0 && err.Error() != test.err {
+			t.Errorf("%d failed. Expected err: '%v' got err: '%v'", i, test.err, err)
+		}
+	}
+}

accounts/abi/unpack.go

@@ -0,0 +1,295 @@
+// Copyright 2017 The go-ethereum Authors
+// This file is part of the go-ethereum library.
+//
+// The go-ethereum library is free software: you can redistribute it and/or modify
+// it under the terms of the GNU Lesser General Public License as published by
+// the Free Software Foundation, either version 3 of the License, or
+// (at your option) any later version.
+//
+// The go-ethereum library is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+// GNU Lesser General Public License for more details.
+//
+// You should have received a copy of the GNU Lesser General Public License
+// along with the go-ethereum library. If not, see <http://www.gnu.org/licenses/>.
+
+package abi
+
+import (
+	"encoding/binary"
+	"fmt"
+	"math/big"
+	"reflect"
+
+	"github.com/ethereum/go-ethereum/common"
+)
+
+var (
+	maxUint256 = big.NewInt(0).Add(
+		big.NewInt(0).Exp(big.NewInt(2), big.NewInt(256), nil),
+		big.NewInt(-1))
+	maxInt256 = big.NewInt(0).Add(
+		big.NewInt(0).Exp(big.NewInt(2), big.NewInt(255), nil),
+		big.NewInt(-1))
+)
+
+// reads the integer based on its kind
+func readInteger(typ byte, kind reflect.Kind, b []byte) interface{} {
+	switch kind {
+	case reflect.Uint8:
+		return b[len(b)-1]
+	case reflect.Uint16:
+		return binary.BigEndian.Uint16(b[len(b)-2:])
+	case reflect.Uint32:
+		return binary.BigEndian.Uint32(b[len(b)-4:])
+	case reflect.Uint64:
+		return binary.BigEndian.Uint64(b[len(b)-8:])
+	case reflect.Int8:
+		return int8(b[len(b)-1])
+	case reflect.Int16:
+		return int16(binary.BigEndian.Uint16(b[len(b)-2:]))
+	case reflect.Int32:
+		return int32(binary.BigEndian.Uint32(b[len(b)-4:]))
+	case reflect.Int64:
+		return int64(binary.BigEndian.Uint64(b[len(b)-8:]))
+	default:
+		// the only case lefts for integer is int256/uint256.
+		// big.SetBytes can't tell if a number is negative, positive on itself.
+		// On EVM, if the returned number > max int256, it is negative.
+		ret := new(big.Int).SetBytes(b)
+		if typ == UintTy {
+			return ret
+		}
+
+		if ret.Cmp(maxInt256) > 0 {
+			ret.Add(maxUint256, big.NewInt(0).Neg(ret))
+			ret.Add(ret, big.NewInt(1))
+			ret.Neg(ret)
+		}
+		return ret
+	}
+}
+
+// reads a bool
+func readBool(word []byte) (bool, error) {
+	for _, b := range word[:31] {
+		if b != 0 {
+			return false, errBadBool
+		}
+	}
+	switch word[31] {
+	case 0:
+		return false, nil
+	case 1:
+		return true, nil
+	default:
+		return false, errBadBool
+	}
+}
+
+// A function type is simply the address with the function selection signature at the end.
+// This enforces that standard by always presenting it as a 24-array (address + sig = 24 bytes)
+func readFunctionType(t Type, word []byte) (funcTy [24]byte, err error) {
+	if t.T != FunctionTy {
+		return [24]byte{}, fmt.Errorf("abi: invalid type in call to make function type byte array")
+	}
+	if garbage := binary.BigEndian.Uint64(word[24:32]); garbage != 0 {
+		err = fmt.Errorf("abi: got improperly encoded function type, got %v", word)
+	} else {
+		copy(funcTy[:], word[0:24])
+	}
+	return
+}
+
+// through reflection, creates a fixed array to be read from
+func readFixedBytes(t Type, word []byte) (interface{}, error) {
+	if t.T != FixedBytesTy {
+		return nil, fmt.Errorf("abi: invalid type in call to make fixed byte array")
+	}
+	// convert
+	array := reflect.New(t.Type).Elem()
+
+	reflect.Copy(array, reflect.ValueOf(word[0:t.Size]))
+	return array.Interface(), nil
+
+}
+
+// iteratively unpack elements
+func forEachUnpack(t Type, output []byte, start, size int) (interface{}, error) {
+	if size < 0 {
+		return nil, fmt.Errorf("cannot marshal input to array, size is negative (%d)", size)
+	}
+	if start+32*size > len(output) {
+		return nil, fmt.Errorf("abi: cannot marshal in to go array: offset %d would go over slice boundary (len=%d)", len(output), start+32*size)
+	}
+
+	// this value will become our slice or our array, depending on the type
+	var refSlice reflect.Value
+
+	if t.T == SliceTy {
+		// declare our slice
+		refSlice = reflect.MakeSlice(t.Type, size, size)
+	} else if t.T == ArrayTy {
+		// declare our array
+		refSlice = reflect.New(t.Type).Elem()
+	} else {
+		return nil, fmt.Errorf("abi: invalid type in array/slice unpacking stage")
+	}
+
+	// Arrays have packed elements, resulting in longer unpack steps.
+	// Slices have just 32 bytes per element (pointing to the contents).
+	elemSize := getTypeSize(*t.Elem)
+
+	for i, j := start, 0; j < size; i, j = i+elemSize, j+1 {
+		inter, err := toGoType(i, *t.Elem, output)
+		if err != nil {
+			return nil, err
+		}
+
+		// append the item to our reflect slice
+		refSlice.Index(j).Set(reflect.ValueOf(inter))
+	}
+
+	// return the interface
+	return refSlice.Interface(), nil
+}
+
+func forTupleUnpack(t Type, output []byte) (interface{}, error) {
+	retval := reflect.New(t.Type).Elem()
+	virtualArgs := 0
+	for index, elem := range t.TupleElems {
+		marshalledValue, err := toGoType((index+virtualArgs)*32, *elem, output)
+		if elem.T == ArrayTy && !isDynamicType(*elem) {
+			// If we have a static array, like [3]uint256, these are coded as
+			// just like uint256,uint256,uint256.
+			// This means that we need to add two 'virtual' arguments when
+			// we count the index from now on.
+			//
+			// Array values nested multiple levels deep are also encoded inline:
+			// [2][3]uint256: uint256,uint256,uint256,uint256,uint256,uint256
+			//
+			// Calculate the full array size to get the correct offset for the next argument.
+			// Decrement it by 1, as the normal index increment is still applied.
+			virtualArgs += getTypeSize(*elem)/32 - 1
+		} else if elem.T == TupleTy && !isDynamicType(*elem) {
+			// If we have a static tuple, like (uint256, bool, uint256), these are
+			// coded as just like uint256,bool,uint256
+			virtualArgs += getTypeSize(*elem)/32 - 1
+		}
+		if err != nil {
+			return nil, err
+		}
+		retval.Field(index).Set(reflect.ValueOf(marshalledValue))
+	}
+	return retval.Interface(), nil
+}
+
+// toGoType parses the output bytes and recursively assigns the value of these bytes
+// into a go type with accordance with the ABI spec.
+func toGoType(index int, t Type, output []byte) (interface{}, error) {
+	if index+32 > len(output) {
+		return nil, fmt.Errorf("abi: cannot marshal in to go type: length insufficient %d require %d", len(output), index+32)
+	}
+
+	var (
+		returnOutput  []byte
+		begin, length int
+		err           error
+	)
+
+	// if we require a length prefix, find the beginning word and size returned.
+	if t.requiresLengthPrefix() {
+		begin, length, err = lengthPrefixPointsTo(index, output)
+		if err != nil {
+			return nil, err
+		}
+	} else {
+		returnOutput = output[index : index+32]
+	}
+
+	switch t.T {
+	case TupleTy:
+		if isDynamicType(t) {
+			begin, err := tuplePointsTo(index, output)
+			if err != nil {
+				return nil, err
+			}
+			return forTupleUnpack(t, output[begin:])
+		} else {
+			return forTupleUnpack(t, output[index:])
+		}
+	case SliceTy:
+		return forEachUnpack(t, output[begin:], 0, length)
+	case ArrayTy:
+		if isDynamicType(*t.Elem) {
+			offset := int64(binary.BigEndian.Uint64(returnOutput[len(returnOutput)-8:]))
+			return forEachUnpack(t, output[offset:], 0, t.Size)
+		}
+		return forEachUnpack(t, output[index:], 0, t.Size)
+	case StringTy: // variable arrays are written at the end of the return bytes
+		return string(output[begin : begin+length]), nil
+	case IntTy, UintTy:
+		return readInteger(t.T, t.Kind, returnOutput), nil
+	case BoolTy:
+		return readBool(returnOutput)
+	case AddressTy:
+		return common.BytesToAddress(returnOutput), nil
+	case HashTy:
+		return common.BytesToHash(returnOutput), nil
+	case BytesTy:
+		return output[begin : begin+length], nil
+	case FixedBytesTy:
+		return readFixedBytes(t, returnOutput)
+	case FunctionTy:
+		return readFunctionType(t, returnOutput)
+	default:
+		return nil, fmt.Errorf("abi: unknown type %v", t.T)
+	}
+}
+
+// interprets a 32 byte slice as an offset and then determines which indice to look to decode the type.
+func lengthPrefixPointsTo(index int, output []byte) (start int, length int, err error) {
+	bigOffsetEnd := big.NewInt(0).SetBytes(output[index : index+32])
+	bigOffsetEnd.Add(bigOffsetEnd, common.Big32)
+	outputLength := big.NewInt(int64(len(output)))
+
+	if bigOffsetEnd.Cmp(outputLength) > 0 {
+		return 0, 0, fmt.Errorf("abi: cannot marshal in to go slice: offset %v would go over slice boundary (len=%v)", bigOffsetEnd, outputLength)
+	}
+
+	if bigOffsetEnd.BitLen() > 63 {
+		return 0, 0, fmt.Errorf("abi offset larger than int64: %v", bigOffsetEnd)
+	}
+
+	offsetEnd := int(bigOffsetEnd.Uint64())
+	lengthBig := big.NewInt(0).SetBytes(output[offsetEnd-32 : offsetEnd])
+
+	totalSize := big.NewInt(0)
+	totalSize.Add(totalSize, bigOffsetEnd)
+	totalSize.Add(totalSize, lengthBig)
+	if totalSize.BitLen() > 63 {
+		return 0, 0, fmt.Errorf("abi: length larger than int64: %v", totalSize)
+	}
+
+	if totalSize.Cmp(outputLength) > 0 {
+		return 0, 0, fmt.Errorf("abi: cannot marshal in to go type: length insufficient %v require %v", outputLength, totalSize)
+	}
+	start = int(bigOffsetEnd.Uint64())
+	length = int(lengthBig.Uint64())
+	return
+}
+
+// tuplePointsTo resolves the location reference for dynamic tuple.
+func tuplePointsTo(index int, output []byte) (start int, err error) {
+	offset := big.NewInt(0).SetBytes(output[index : index+32])
+	outputLen := big.NewInt(int64(len(output)))
+
+	if offset.Cmp(big.NewInt(int64(len(output)))) > 0 {
+		return 0, fmt.Errorf("abi: cannot marshal in to go slice: offset %v would go over slice boundary (len=%v)", offset, outputLen)
+	}
+	if offset.BitLen() > 63 {
+		return 0, fmt.Errorf("abi offset larger than int64: %v", offset)
+	}
+	return int(offset.Uint64()), nil
+}

accounts/accounts.go

@@ -0,0 +1,222 @@
+// Copyright 2017 The go-ethereum Authors
+// This file is part of the go-ethereum library.
+//
+// The go-ethereum library is free software: you can redistribute it and/or modify
+// it under the terms of the GNU Lesser General Public License as published by
+// the Free Software Foundation, either version 3 of the License, or
+// (at your option) any later version.
+//
+// The go-ethereum library is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+// GNU Lesser General Public License for more details.
+//
+// You should have received a copy of the GNU Lesser General Public License
+// along with the go-ethereum library. If not, see <http://www.gnu.org/licenses/>.
+
+// Package accounts implements high level Ethereum account management.
+package accounts
+
+import (
+	"fmt"
+	"math/big"
+
+	ethereum "github.com/ethereum/go-ethereum"
+	"github.com/ethereum/go-ethereum/common"
+	"github.com/ethereum/go-ethereum/core/types"
+	"github.com/ethereum/go-ethereum/event"
+	"golang.org/x/crypto/sha3"
+)
+
+// Account represents an Ethereum account located at a specific location defined
+// by the optional URL field.
+type Account struct {
+	Address common.Address `json:"address"` // Ethereum account address derived from the key
+	URL     URL            `json:"url"`     // Optional resource locator within a backend
+}
+
+const (
+	MimetypeTextWithValidator = "text/validator"
+	MimetypeTypedData         = "data/typed"
+	MimetypeClique            = "application/x-clique-header"
+	MimetypeTextPlain         = "text/plain"
+)
+
+// Wallet represents a software or hardware wallet that might contain one or more
+// accounts (derived from the same seed).
+type Wallet interface {
+	// URL retrieves the canonical path under which this wallet is reachable. It is
+	// user by upper layers to define a sorting order over all wallets from multiple
+	// backends.
+	URL() URL
+
+	// Status returns a textual status to aid the user in the current state of the
+	// wallet. It also returns an error indicating any failure the wallet might have
+	// encountered.
+	Status() (string, error)
+
+	// Open initializes access to a wallet instance. It is not meant to unlock or
+	// decrypt account keys, rather simply to establish a connection to hardware
+	// wallets and/or to access derivation seeds.
+	//
+	// The passphrase parameter may or may not be used by the implementation of a
+	// particular wallet instance. The reason there is no passwordless open method
+	// is to strive towards a uniform wallet handling, oblivious to the different
+	// backend providers.
+	//
+	// Please note, if you open a wallet, you must close it to release any allocated
+	// resources (especially important when working with hardware wallets).
+	Open(passphrase string) error
+
+	// Close releases any resources held by an open wallet instance.
+	Close() error
+
+	// Accounts retrieves the list of signing accounts the wallet is currently aware
+	// of. For hierarchical deterministic wallets, the list will not be exhaustive,
+	// rather only contain the accounts explicitly pinned during account derivation.
+	Accounts() []Account
+
+	// Contains returns whether an account is part of this particular wallet or not.
+	Contains(account Account) bool
+
+	// Derive attempts to explicitly derive a hierarchical deterministic account at
+	// the specified derivation path. If requested, the derived account will be added
+	// to the wallet's tracked account list.
+	Derive(path DerivationPath, pin bool) (Account, error)
+
+	// SelfDerive sets a base account derivation path from which the wallet attempts
+	// to discover non zero accounts and automatically add them to list of tracked
+	// accounts.
+	//
+	// Note, self derivaton will increment the last component of the specified path
+	// opposed to decending into a child path to allow discovering accounts starting
+	// from non zero components.
+	//
+	// Some hardware wallets switched derivation paths through their evolution, so
+	// this method supports providing multiple bases to discover old user accounts
+	// too. Only the last base will be used to derive the next empty account.
+	//
+	// You can disable automatic account discovery by calling SelfDerive with a nil
+	// chain state reader.
+	SelfDerive(bases []DerivationPath, chain ethereum.ChainStateReader)
+
+	// SignData requests the wallet to sign the hash of the given data
+	// It looks up the account specified either solely via its address contained within,
+	// or optionally with the aid of any location metadata from the embedded URL field.
+	//
+	// If the wallet requires additional authentication to sign the request (e.g.
+	// a password to decrypt the account, or a PIN code o verify the transaction),
+	// an AuthNeededError instance will be returned, containing infos for the user
+	// about which fields or actions are needed. The user may retry by providing
+	// the needed details via SignDataWithPassphrase, or by other means (e.g. unlock
+	// the account in a keystore).
+	SignData(account Account, mimeType string, data []byte) ([]byte, error)
+
+	// SignDataWithPassphrase is identical to SignData, but also takes a password
+	// NOTE: there's an chance that an erroneous call might mistake the two strings, and
+	// supply password in the mimetype field, or vice versa. Thus, an implementation
+	// should never echo the mimetype or return the mimetype in the error-response
+	SignDataWithPassphrase(account Account, passphrase, mimeType string, data []byte) ([]byte, error)
+
+	// SignText requests the wallet to sign the hash of a given piece of data, prefixed
+	// by the Ethereum prefix scheme
+	// It looks up the account specified either solely via its address contained within,
+	// or optionally with the aid of any location metadata from the embedded URL field.
+	//
+	// If the wallet requires additional authentication to sign the request (e.g.
+	// a password to decrypt the account, or a PIN code o verify the transaction),
+	// an AuthNeededError instance will be returned, containing infos for the user
+	// about which fields or actions are needed. The user may retry by providing
+	// the needed details via SignHashWithPassphrase, or by other means (e.g. unlock
+	// the account in a keystore).
+	SignText(account Account, text []byte) ([]byte, error)
+
+	// SignTextWithPassphrase is identical to Signtext, but also takes a password
+	SignTextWithPassphrase(account Account, passphrase string, hash []byte) ([]byte, error)
+
+	// SignTx requests the wallet to sign the given transaction.
+	//
+	// It looks up the account specified either solely via its address contained within,
+	// or optionally with the aid of any location metadata from the embedded URL field.
+	//
+	// If the wallet requires additional authentication to sign the request (e.g.
+	// a password to decrypt the account, or a PIN code to verify the transaction),
+	// an AuthNeededError instance will be returned, containing infos for the user
+	// about which fields or actions are needed. The user may retry by providing
+	// the needed details via SignTxWithPassphrase, or by other means (e.g. unlock
+	// the account in a keystore).
+	SignTx(account Account, tx *types.Transaction, chainID *big.Int) (*types.Transaction, error)
+
+	// SignTxWithPassphrase is identical to SignTx, but also takes a password
+	SignTxWithPassphrase(account Account, passphrase string, tx *types.Transaction, chainID *big.Int) (*types.Transaction, error)
+}
+
+// Backend is a "wallet provider" that may contain a batch of accounts they can
+// sign transactions with and upon request, do so.
+type Backend interface {
+	// Wallets retrieves the list of wallets the backend is currently aware of.
+	//
+	// The returned wallets are not opened by default. For software HD wallets this
+	// means that no base seeds are decrypted, and for hardware wallets that no actual
+	// connection is established.
+	//
+	// The resulting wallet list will be sorted alphabetically based on its internal
+	// URL assigned by the backend. Since wallets (especially hardware) may come and
+	// go, the same wallet might appear at a different positions in the list during
+	// subsequent retrievals.
+	Wallets() []Wallet
+
+	// Subscribe creates an async subscription to receive notifications when the
+	// backend detects the arrival or departure of a wallet.
+	Subscribe(sink chan<- WalletEvent) event.Subscription
+}
+
+// TextHash is a helper function that calculates a hash for the given message that can be
+// safely used to calculate a signature from.
+//
+// The hash is calulcated as
+//   keccak256("\x19Ethereum Signed Message:\n"${message length}${message}).
+//
+// This gives context to the signed message and prevents signing of transactions.
+func TextHash(data []byte) []byte {
+	hash, _ := TextAndHash(data)
+	return hash
+}
+
+// TextAndHash is a helper function that calculates a hash for the given message that can be
+// safely used to calculate a signature from.
+//
+// The hash is calulcated as
+//   keccak256("\x19Ethereum Signed Message:\n"${message length}${message}).
+//
+// This gives context to the signed message and prevents signing of transactions.
+func TextAndHash(data []byte) ([]byte, string) {
+	msg := fmt.Sprintf("\x19Ethereum Signed Message:\n%d%s", len(data), string(data))
+	hasher := sha3.NewLegacyKeccak256()
+	hasher.Write([]byte(msg))
+	return hasher.Sum(nil), msg
+}
+
+// WalletEventType represents the different event types that can be fired by
+// the wallet subscription subsystem.
+type WalletEventType int
+
+const (
+	// WalletArrived is fired when a new wallet is detected either via USB or via
+	// a filesystem event in the keystore.
+	WalletArrived WalletEventType = iota
+
+	// WalletOpened is fired when a wallet is successfully opened with the purpose
+	// of starting any background processes such as automatic key derivation.
+	WalletOpened
+
+	// WalletDropped
+	WalletDropped
+)
+
+// WalletEvent is an event fired by an account backend when a wallet arrival or
+// departure is detected.
+type WalletEvent struct {
+	Wallet Wallet          // Wallet instance arrived or departed
+	Kind   WalletEventType // Event type that happened in the system
+}

accounts/accounts_test.go

@@ -0,0 +1,32 @@
+// Copyright 2019 The go-ethereum Authors
+// This file is part of the go-ethereum library.
+//
+// The go-ethereum library is free software: you can redistribute it and/or modify
+// it under the terms of the GNU Lesser General Public License as published by
+// the Free Software Foundation, either version 3 of the License, or
+// (at your option) any later version.
+//
+// The go-ethereum library is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+// GNU Lesser General Public License for more details.
+//
+// You should have received a copy of the GNU Lesser General Public License
+// along with the go-ethereum library. If not, see <http://www.gnu.org/licenses/>.
+
+package accounts
+
+import (
+	"bytes"
+	"testing"
+
+	"github.com/ethereum/go-ethereum/common/hexutil"
+)
+
+func TestTextHash(t *testing.T) {
+	hash := TextHash([]byte("Hello Joe"))
+	want := hexutil.MustDecode("0xa080337ae51c4e064c189e113edd0ba391df9206e2f49db658bb32cf2911730b")
+	if !bytes.Equal(hash, want) {
+		t.Fatalf("wrong hash: %x", hash)
+	}
+}

accounts/errors.go

@@ -0,0 +1,68 @@
+// Copyright 2017 The go-ethereum Authors
+// This file is part of the go-ethereum library.
+//
+// The go-ethereum library is free software: you can redistribute it and/or modify
+// it under the terms of the GNU Lesser General Public License as published by
+// the Free Software Foundation, either version 3 of the License, or
+// (at your option) any later version.
+//
+// The go-ethereum library is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+// GNU Lesser General Public License for more details.
+//
+// You should have received a copy of the GNU Lesser General Public License
+// along with the go-ethereum library. If not, see <http://www.gnu.org/licenses/>.
+
+package accounts
+
+import (
+	"errors"
+	"fmt"
+)
+
+// ErrUnknownAccount is returned for any requested operation for which no backend
+// provides the specified account.
+var ErrUnknownAccount = errors.New("unknown account")
+
+// ErrUnknownWallet is returned for any requested operation for which no backend
+// provides the specified wallet.
+var ErrUnknownWallet = errors.New("unknown wallet")
+
+// ErrNotSupported is returned when an operation is requested from an account
+// backend that it does not support.
+var ErrNotSupported = errors.New("not supported")
+
+// ErrInvalidPassphrase is returned when a decryption operation receives a bad
+// passphrase.
+var ErrInvalidPassphrase = errors.New("invalid passphrase")
+
+// ErrWalletAlreadyOpen is returned if a wallet is attempted to be opened the
+// second time.
+var ErrWalletAlreadyOpen = errors.New("wallet already open")
+
+// ErrWalletClosed is returned if a wallet is attempted to be opened the
+// secodn time.
+var ErrWalletClosed = errors.New("wallet closed")
+
+// AuthNeededError is returned by backends for signing requests where the user
+// is required to provide further authentication before signing can succeed.
+//
+// This usually means either that a password needs to be supplied, or perhaps a
+// one time PIN code displayed by some hardware device.
+type AuthNeededError struct {
+	Needed string // Extra authentication the user needs to provide
+}
+
+// NewAuthNeededError creates a new authentication error with the extra details
+// about the needed fields set.
+func NewAuthNeededError(needed string) error {
+	return &AuthNeededError{
+		Needed: needed,
+	}
+}
+
+// Error implements the standard error interface.
+func (err *AuthNeededError) Error() string {
+	return fmt.Sprintf("authentication needed: %s", err.Needed)
+}

accounts/external/backend.go

@@ -0,0 +1,228 @@
+// Copyright 2018 The go-ethereum Authors
+// This file is part of go-ethereum.
+//
+// go-ethereum is free software: you can redistribute it and/or modify
+// it under the terms of the GNU General Public License as published by
+// the Free Software Foundation, either version 3 of the License, or
+// (at your option) any later version.
+//
+// go-ethereum is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+// GNU General Public License for more details.
+//
+// You should have received a copy of the GNU General Public License
+// along with go-ethereum. If not, see <http://www.gnu.org/licenses/>.
+
+package external
+
+import (
+	"fmt"
+	"math/big"
+	"sync"
+
+	"github.com/ethereum/go-ethereum"
+	"github.com/ethereum/go-ethereum/accounts"
+	"github.com/ethereum/go-ethereum/common"
+	"github.com/ethereum/go-ethereum/common/hexutil"
+	"github.com/ethereum/go-ethereum/core/types"
+	"github.com/ethereum/go-ethereum/event"
+	"github.com/ethereum/go-ethereum/internal/ethapi"
+	"github.com/ethereum/go-ethereum/log"
+	"github.com/ethereum/go-ethereum/rpc"
+	"github.com/ethereum/go-ethereum/signer/core"
+)
+
+type ExternalBackend struct {
+	signers []accounts.Wallet
+}
+
+func (eb *ExternalBackend) Wallets() []accounts.Wallet {
+	return eb.signers
+}
+
+func NewExternalBackend(endpoint string) (*ExternalBackend, error) {
+	signer, err := NewExternalSigner(endpoint)
+	if err != nil {
+		return nil, err
+	}
+	return &ExternalBackend{
+		signers: []accounts.Wallet{signer},
+	}, nil
+}
+
+func (eb *ExternalBackend) Subscribe(sink chan<- accounts.WalletEvent) event.Subscription {
+	return event.NewSubscription(func(quit <-chan struct{}) error {
+		<-quit
+		return nil
+	})
+}
+
+// ExternalSigner provides an API to interact with an external signer (clef)
+// It proxies request to the external signer while forwarding relevant
+// request headers
+type ExternalSigner struct {
+	client   *rpc.Client
+	endpoint string
+	status   string
+	cacheMu  sync.RWMutex
+	cache    []accounts.Account
+}
+
+func NewExternalSigner(endpoint string) (*ExternalSigner, error) {
+	client, err := rpc.Dial(endpoint)
+	if err != nil {
+		return nil, err
+	}
+	extsigner := &ExternalSigner{
+		client:   client,
+		endpoint: endpoint,
+	}
+	// Check if reachable
+	version, err := extsigner.pingVersion()
+	if err != nil {
+		return nil, err
+	}
+	extsigner.status = fmt.Sprintf("ok [version=%v]", version)
+	return extsigner, nil
+}
+
+func (api *ExternalSigner) URL() accounts.URL {
+	return accounts.URL{
+		Scheme: "extapi",
+		Path:   api.endpoint,
+	}
+}
+
+func (api *ExternalSigner) Status() (string, error) {
+	return api.status, nil
+}
+
+func (api *ExternalSigner) Open(passphrase string) error {
+	return fmt.Errorf("operation not supported on external signers")
+}
+
+func (api *ExternalSigner) Close() error {
+	return fmt.Errorf("operation not supported on external signers")
+}
+
+func (api *ExternalSigner) Accounts() []accounts.Account {
+	var accnts []accounts.Account
+	res, err := api.listAccounts()
+	if err != nil {
+		log.Error("account listing failed", "error", err)
+		return accnts
+	}
+	for _, addr := range res {
+		accnts = append(accnts, accounts.Account{
+			URL: accounts.URL{
+				Scheme: "extapi",
+				Path:   api.endpoint,
+			},
+			Address: addr,
+		})
+	}
+	api.cacheMu.Lock()
+	api.cache = accnts
+	api.cacheMu.Unlock()
+	return accnts
+}
+
+func (api *ExternalSigner) Contains(account accounts.Account) bool {
+	api.cacheMu.RLock()
+	defer api.cacheMu.RUnlock()
+	for _, a := range api.cache {
+		if a.Address == account.Address && (account.URL == (accounts.URL{}) || account.URL == api.URL()) {
+			return true
+		}
+	}
+	return false
+}
+
+func (api *ExternalSigner) Derive(path accounts.DerivationPath, pin bool) (accounts.Account, error) {
+	return accounts.Account{}, fmt.Errorf("operation not supported on external signers")
+}
+
+func (api *ExternalSigner) SelfDerive(bases []accounts.DerivationPath, chain ethereum.ChainStateReader) {
+	log.Error("operation SelfDerive not supported on external signers")
+}
+
+func (api *ExternalSigner) signHash(account accounts.Account, hash []byte) ([]byte, error) {
+	return []byte{}, fmt.Errorf("operation not supported on external signers")
+}
+
+// SignData signs keccak256(data). The mimetype parameter describes the type of data being signed
+func (api *ExternalSigner) SignData(account accounts.Account, mimeType string, data []byte) ([]byte, error) {
+	var res hexutil.Bytes
+	var signAddress = common.NewMixedcaseAddress(account.Address)
+	if err := api.client.Call(&res, "account_signData",
+		mimeType,
+		&signAddress, // Need to use the pointer here, because of how MarshalJSON is defined
+		hexutil.Encode(data)); err != nil {
+		return nil, err
+	}
+	// If V is on 27/28-form, convert to to 0/1 for Clique
+	if mimeType == accounts.MimetypeClique && (res[64] == 27 || res[64] == 28) {
+		res[64] -= 27 // Transform V from 27/28 to 0/1 for Clique use
+	}
+	return res, nil
+}
+
+func (api *ExternalSigner) SignText(account accounts.Account, text []byte) ([]byte, error) {
+	var res hexutil.Bytes
+	var signAddress = common.NewMixedcaseAddress(account.Address)
+	if err := api.client.Call(&res, "account_signData",
+		accounts.MimetypeTextPlain,
+		&signAddress, // Need to use the pointer here, because of how MarshalJSON is defined
+		hexutil.Encode(text)); err != nil {
+		return nil, err
+	}
+	return res, nil
+}
+
+func (api *ExternalSigner) SignTx(account accounts.Account, tx *types.Transaction, chainID *big.Int) (*types.Transaction, error) {
+	res := ethapi.SignTransactionResult{}
+	to := common.NewMixedcaseAddress(*tx.To())
+	data := hexutil.Bytes(tx.Data())
+	args := &core.SendTxArgs{
+		Data:     &data,
+		Nonce:    hexutil.Uint64(tx.Nonce()),
+		Value:    hexutil.Big(*tx.Value()),
+		Gas:      hexutil.Uint64(tx.Gas()),
+		GasPrice: hexutil.Big(*tx.GasPrice()),
+		To:       &to,
+		From:     common.NewMixedcaseAddress(account.Address),
+	}
+
+	if err := api.client.Call(&res, "account_signTransaction", args); err != nil {
+		return nil, err
+	}
+	return res.Tx, nil
+}
+
+func (api *ExternalSigner) SignTextWithPassphrase(account accounts.Account, passphrase string, text []byte) ([]byte, error) {
+	return []byte{}, fmt.Errorf("passphrase-operations not supported on external signers")
+}
+
+func (api *ExternalSigner) SignTxWithPassphrase(account accounts.Account, passphrase string, tx *types.Transaction, chainID *big.Int) (*types.Transaction, error) {
+	return nil, fmt.Errorf("passphrase-operations not supported on external signers")
+}
+func (api *ExternalSigner) SignDataWithPassphrase(account accounts.Account, passphrase, mimeType string, data []byte) ([]byte, error) {
+	return nil, fmt.Errorf("passphrase-operations not supported on external signers")
+}
+
+func (api *ExternalSigner) listAccounts() ([]common.Address, error) {
+	var res []common.Address
+	if err := api.client.Call(&res, "account_list"); err != nil {
+		return nil, err
+	}
+	return res, nil
+}
+
+func (api *ExternalSigner) pingVersion() (string, error) {
+	var v string
+	if err := api.client.Call(&v, "account_version"); err != nil {
+		return "", err
+	}
+	return v, nil
+}

accounts/hd.go

@@ -0,0 +1,152 @@
+// Copyright 2017 The go-ethereum Authors
+// This file is part of the go-ethereum library.
+//
+// The go-ethereum library is free software: you can redistribute it and/or modify
+// it under the terms of the GNU Lesser General Public License as published by
+// the Free Software Foundation, either version 3 of the License, or
+// (at your option) any later version.
+//
+// The go-ethereum library is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+// GNU Lesser General Public License for more details.
+//
+// You should have received a copy of the GNU Lesser General Public License
+// along with the go-ethereum library. If not, see <http://www.gnu.org/licenses/>.
+
+package accounts
+
+import (
+	"encoding/json"
+	"errors"
+	"fmt"
+	"math"
+	"math/big"
+	"strings"
+)
+
+// DefaultRootDerivationPath is the root path to which custom derivation endpoints
+// are appended. As such, the first account will be at m/44'/60'/0'/0, the second
+// at m/44'/60'/0'/1, etc.
+var DefaultRootDerivationPath = DerivationPath{0x80000000 + 44, 0x80000000 + 60, 0x80000000 + 0, 0}
+
+// DefaultBaseDerivationPath is the base path from which custom derivation endpoints
+// are incremented. As such, the first account will be at m/44'/60'/0'/0/0, the second
+// at m/44'/60'/0'/0/1, etc.
+var DefaultBaseDerivationPath = DerivationPath{0x80000000 + 44, 0x80000000 + 60, 0x80000000 + 0, 0, 0}
+
+// LegacyLedgerBaseDerivationPath is the legacy base path from which custom derivation
+// endpoints are incremented. As such, the first account will be at m/44'/60'/0'/0, the
+// second at m/44'/60'/0'/1, etc.
+var LegacyLedgerBaseDerivationPath = DerivationPath{0x80000000 + 44, 0x80000000 + 60, 0x80000000 + 0, 0}
+
+// DerivationPath represents the computer friendly version of a hierarchical
+// deterministic wallet account derivaion path.
+//
+// The BIP-32 spec https://github.com/bitcoin/bips/blob/master/bip-0032.mediawiki
+// defines derivation paths to be of the form:
+//
+//   m / purpose' / coin_type' / account' / change / address_index
+//
+// The BIP-44 spec https://github.com/bitcoin/bips/blob/master/bip-0044.mediawiki
+// defines that the `purpose` be 44' (or 0x8000002C) for crypto currencies, and
+// SLIP-44 https://github.com/satoshilabs/slips/blob/master/slip-0044.md assigns
+// the `coin_type` 60' (or 0x8000003C) to Ethereum.
+//
+// The root path for Ethereum is m/44'/60'/0'/0 according to the specification
+// from https://github.com/ethereum/EIPs/issues/84, albeit it's not set in stone
+// yet whether accounts should increment the last component or the children of
+// that. We will go with the simpler approach of incrementing the last component.
+type DerivationPath []uint32
+
+// ParseDerivationPath converts a user specified derivation path string to the
+// internal binary representation.
+//
+// Full derivation paths need to start with the `m/` prefix, relative derivation
+// paths (which will get appended to the default root path) must not have prefixes
+// in front of the first element. Whitespace is ignored.
+func ParseDerivationPath(path string) (DerivationPath, error) {
+	var result DerivationPath
+
+	// Handle absolute or relative paths
+	components := strings.Split(path, "/")
+	switch {
+	case len(components) == 0:
+		return nil, errors.New("empty derivation path")
+
+	case strings.TrimSpace(components[0]) == "":
+		return nil, errors.New("ambiguous path: use 'm/' prefix for absolute paths, or no leading '/' for relative ones")
+
+	case strings.TrimSpace(components[0]) == "m":
+		components = components[1:]
+
+	default:
+		result = append(result, DefaultRootDerivationPath...)
+	}
+	// All remaining components are relative, append one by one
+	if len(components) == 0 {
+		return nil, errors.New("empty derivation path") // Empty relative paths
+	}
+	for _, component := range components {
+		// Ignore any user added whitespace
+		component = strings.TrimSpace(component)
+		var value uint32
+
+		// Handle hardened paths
+		if strings.HasSuffix(component, "'") {
+			value = 0x80000000
+			component = strings.TrimSpace(strings.TrimSuffix(component, "'"))
+		}
+		// Handle the non hardened component
+		bigval, ok := new(big.Int).SetString(component, 0)
+		if !ok {
+			return nil, fmt.Errorf("invalid component: %s", component)
+		}
+		max := math.MaxUint32 - value
+		if bigval.Sign() < 0 || bigval.Cmp(big.NewInt(int64(max))) > 0 {
+			if value == 0 {
+				return nil, fmt.Errorf("component %v out of allowed range [0, %d]", bigval, max)
+			}
+			return nil, fmt.Errorf("component %v out of allowed hardened range [0, %d]", bigval, max)
+		}
+		value += uint32(bigval.Uint64())
+
+		// Append and repeat
+		result = append(result, value)
+	}
+	return result, nil
+}
+
+// String implements the stringer interface, converting a binary derivation path
+// to its canonical representation.
+func (path DerivationPath) String() string {
+	result := "m"
+	for _, component := range path {
+		var hardened bool
+		if component >= 0x80000000 {
+			component -= 0x80000000
+			hardened = true
+		}
+		result = fmt.Sprintf("%s/%d", result, component)
+		if hardened {
+			result += "'"
+		}
+	}
+	return result
+}
+
+// MarshalJSON turns a derivation path into its json-serialized string
+func (path DerivationPath) MarshalJSON() ([]byte, error) {
+	return json.Marshal(path.String())
+}
+
+// UnmarshalJSON a json-serialized string back into a derivation path
+func (path *DerivationPath) UnmarshalJSON(b []byte) error {
+	var dp string
+	var err error
+	if err = json.Unmarshal(b, &dp); err != nil {
+		return err
+	}
+	*path, err = ParseDerivationPath(dp)
+	return err
+}

accounts/hd_test.go

@@ -0,0 +1,79 @@
+// Copyright 2017 The go-ethereum Authors
+// This file is part of the go-ethereum library.
+//
+// The go-ethereum library is free software: you can redistribute it and/or modify
+// it under the terms of the GNU Lesser General Public License as published by
+// the Free Software Foundation, either version 3 of the License, or
+// (at your option) any later version.
+//
+// The go-ethereum library is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+// GNU Lesser General Public License for more details.
+//
+// You should have received a copy of the GNU Lesser General Public License
+// along with the go-ethereum library. If not, see <http://www.gnu.org/licenses/>.
+
+package accounts
+
+import (
+	"reflect"
+	"testing"
+)
+
+// Tests that HD derivation paths can be correctly parsed into our internal binary
+// representation.
+func TestHDPathParsing(t *testing.T) {
+	tests := []struct {
+		input  string
+		output DerivationPath
+	}{
+		// Plain absolute derivation paths
+		{"m/44'/60'/0'/0", DerivationPath{0x80000000 + 44, 0x80000000 + 60, 0x80000000 + 0, 0}},
+		{"m/44'/60'/0'/128", DerivationPath{0x80000000 + 44, 0x80000000 + 60, 0x80000000 + 0, 128}},
+		{"m/44'/60'/0'/0'", DerivationPath{0x80000000 + 44, 0x80000000 + 60, 0x80000000 + 0, 0x80000000 + 0}},
+		{"m/44'/60'/0'/128'", DerivationPath{0x80000000 + 44, 0x80000000 + 60, 0x80000000 + 0, 0x80000000 + 128}},
+		{"m/2147483692/2147483708/2147483648/0", DerivationPath{0x80000000 + 44, 0x80000000 + 60, 0x80000000 + 0, 0}},
+		{"m/2147483692/2147483708/2147483648/2147483648", DerivationPath{0x80000000 + 44, 0x80000000 + 60, 0x80000000 + 0, 0x80000000 + 0}},
+
+		// Plain relative derivation paths
+		{"0", DerivationPath{0x80000000 + 44, 0x80000000 + 60, 0x80000000 + 0, 0, 0}},
+		{"128", DerivationPath{0x80000000 + 44, 0x80000000 + 60, 0x80000000 + 0, 0, 128}},
+		{"0'", DerivationPath{0x80000000 + 44, 0x80000000 + 60, 0x80000000 + 0, 0, 0x80000000 + 0}},
+		{"128'", DerivationPath{0x80000000 + 44, 0x80000000 + 60, 0x80000000 + 0, 0, 0x80000000 + 128}},
+		{"2147483648", DerivationPath{0x80000000 + 44, 0x80000000 + 60, 0x80000000 + 0, 0, 0x80000000 + 0}},
+
+		// Hexadecimal absolute derivation paths
+		{"m/0x2C'/0x3c'/0x00'/0x00", DerivationPath{0x80000000 + 44, 0x80000000 + 60, 0x80000000 + 0, 0}},
+		{"m/0x2C'/0x3c'/0x00'/0x80", DerivationPath{0x80000000 + 44, 0x80000000 + 60, 0x80000000 + 0, 128}},
+		{"m/0x2C'/0x3c'/0x00'/0x00'", DerivationPath{0x80000000 + 44, 0x80000000 + 60, 0x80000000 + 0, 0x80000000 + 0}},
+		{"m/0x2C'/0x3c'/0x00'/0x80'", DerivationPath{0x80000000 + 44, 0x80000000 + 60, 0x80000000 + 0, 0x80000000 + 128}},
+		{"m/0x8000002C/0x8000003c/0x80000000/0x00", DerivationPath{0x80000000 + 44, 0x80000000 + 60, 0x80000000 + 0, 0}},
+		{"m/0x8000002C/0x8000003c/0x80000000/0x80000000", DerivationPath{0x80000000 + 44, 0x80000000 + 60, 0x80000000 + 0, 0x80000000 + 0}},
+
+		// Hexadecimal relative derivation paths
+		{"0x00", DerivationPath{0x80000000 + 44, 0x80000000 + 60, 0x80000000 + 0, 0, 0}},
+		{"0x80", DerivationPath{0x80000000 + 44, 0x80000000 + 60, 0x80000000 + 0, 0, 128}},
+		{"0x00'", DerivationPath{0x80000000 + 44, 0x80000000 + 60, 0x80000000 + 0, 0, 0x80000000 + 0}},
+		{"0x80'", DerivationPath{0x80000000 + 44, 0x80000000 + 60, 0x80000000 + 0, 0, 0x80000000 + 128}},
+		{"0x80000000", DerivationPath{0x80000000 + 44, 0x80000000 + 60, 0x80000000 + 0, 0, 0x80000000 + 0}},
+
+		// Weird inputs just to ensure they work
+		{"	m  /   44			'\n/\n   60	\n\n\t'   /\n0 ' /\t\t	0", DerivationPath{0x80000000 + 44, 0x80000000 + 60, 0x80000000 + 0, 0}},
+
+		// Invaid derivation paths
+		{"", nil},              // Empty relative derivation path
+		{"m", nil},             // Empty absolute derivation path
+		{"m/", nil},            // Missing last derivation component
+		{"/44'/60'/0'/0", nil}, // Absolute path without m prefix, might be user error
+		{"m/2147483648'", nil}, // Overflows 32 bit integer
+		{"m/-1'", nil},         // Cannot contain negative number
+	}
+	for i, tt := range tests {
+		if path, err := ParseDerivationPath(tt.input); !reflect.DeepEqual(path, tt.output) {
+			t.Errorf("test %d: parse mismatch: have %v (%v), want %v", i, path, err, tt.output)
+		} else if path == nil && err == nil {
+			t.Errorf("test %d: nil path and error: %v", i, err)
+		}
+	}
+}

accounts/keystore/account_cache.go

@@ -0,0 +1,301 @@
+// Copyright 2017 The go-ethereum Authors
+// This file is part of the go-ethereum library.
+//
+// The go-ethereum library is free software: you can redistribute it and/or modify
+// it under the terms of the GNU Lesser General Public License as published by
+// the Free Software Foundation, either version 3 of the License, or
+// (at your option) any later version.
+//
+// The go-ethereum library is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+// GNU Lesser General Public License for more details.
+//
+// You should have received a copy of the GNU Lesser General Public License
+// along with the go-ethereum library. If not, see <http://www.gnu.org/licenses/>.
+
+package keystore
+
+import (
+	"bufio"
+	"encoding/json"
+	"fmt"
+	"os"
+	"path/filepath"
+	"sort"
+	"strings"
+	"sync"
+	"time"
+
+	mapset "github.com/deckarep/golang-set"
+	"github.com/ethereum/go-ethereum/accounts"
+	"github.com/ethereum/go-ethereum/common"
+	"github.com/ethereum/go-ethereum/log"
+)
+
+// Minimum amount of time between cache reloads. This limit applies if the platform does
+// not support change notifications. It also applies if the keystore directory does not
+// exist yet, the code will attempt to create a watcher at most this often.
+const minReloadInterval = 2 * time.Second
+
+type accountsByURL []accounts.Account
+
+func (s accountsByURL) Len() int           { return len(s) }
+func (s accountsByURL) Less(i, j int) bool { return s[i].URL.Cmp(s[j].URL) < 0 }
+func (s accountsByURL) Swap(i, j int)      { s[i], s[j] = s[j], s[i] }
+
+// AmbiguousAddrError is returned when attempting to unlock
+// an address for which more than one file exists.
+type AmbiguousAddrError struct {
+	Addr    common.Address
+	Matches []accounts.Account
+}
+
+func (err *AmbiguousAddrError) Error() string {
+	files := ""
+	for i, a := range err.Matches {
+		files += a.URL.Path
+		if i < len(err.Matches)-1 {
+			files += ", "
+		}
+	}
+	return fmt.Sprintf("multiple keys match address (%s)", files)
+}
+
+// accountCache is a live index of all accounts in the keystore.
+type accountCache struct {
+	keydir   string
+	watcher  *watcher
+	mu       sync.Mutex
+	all      accountsByURL
+	byAddr   map[common.Address][]accounts.Account
+	throttle *time.Timer
+	notify   chan struct{}
+	fileC    fileCache
+}
+
+func newAccountCache(keydir string) (*accountCache, chan struct{}) {
+	ac := &accountCache{
+		keydir: keydir,
+		byAddr: make(map[common.Address][]accounts.Account),
+		notify: make(chan struct{}, 1),
+		fileC:  fileCache{all: mapset.NewThreadUnsafeSet()},
+	}
+	ac.watcher = newWatcher(ac)
+	return ac, ac.notify
+}
+
+func (ac *accountCache) accounts() []accounts.Account {
+	ac.maybeReload()
+	ac.mu.Lock()
+	defer ac.mu.Unlock()
+	cpy := make([]accounts.Account, len(ac.all))
+	copy(cpy, ac.all)
+	return cpy
+}
+
+func (ac *accountCache) hasAddress(addr common.Address) bool {
+	ac.maybeReload()
+	ac.mu.Lock()
+	defer ac.mu.Unlock()
+	return len(ac.byAddr[addr]) > 0
+}
+
+func (ac *accountCache) add(newAccount accounts.Account) {
+	ac.mu.Lock()
+	defer ac.mu.Unlock()
+
+	i := sort.Search(len(ac.all), func(i int) bool { return ac.all[i].URL.Cmp(newAccount.URL) >= 0 })
+	if i < len(ac.all) && ac.all[i] == newAccount {
+		return
+	}
+	// newAccount is not in the cache.
+	ac.all = append(ac.all, accounts.Account{})
+	copy(ac.all[i+1:], ac.all[i:])
+	ac.all[i] = newAccount
+	ac.byAddr[newAccount.Address] = append(ac.byAddr[newAccount.Address], newAccount)
+}
+
+// note: removed needs to be unique here (i.e. both File and Address must be set).
+func (ac *accountCache) delete(removed accounts.Account) {
+	ac.mu.Lock()
+	defer ac.mu.Unlock()
+
+	ac.all = removeAccount(ac.all, removed)
+	if ba := removeAccount(ac.byAddr[removed.Address], removed); len(ba) == 0 {
+		delete(ac.byAddr, removed.Address)
+	} else {
+		ac.byAddr[removed.Address] = ba
+	}
+}
+
+// deleteByFile removes an account referenced by the given path.
+func (ac *accountCache) deleteByFile(path string) {
+	ac.mu.Lock()
+	defer ac.mu.Unlock()
+	i := sort.Search(len(ac.all), func(i int) bool { return ac.all[i].URL.Path >= path })
+
+	if i < len(ac.all) && ac.all[i].URL.Path == path {
+		removed := ac.all[i]
+		ac.all = append(ac.all[:i], ac.all[i+1:]...)
+		if ba := removeAccount(ac.byAddr[removed.Address], removed); len(ba) == 0 {
+			delete(ac.byAddr, removed.Address)
+		} else {
+			ac.byAddr[removed.Address] = ba
+		}
+	}
+}
+
+func removeAccount(slice []accounts.Account, elem accounts.Account) []accounts.Account {
+	for i := range slice {
+		if slice[i] == elem {
+			return append(slice[:i], slice[i+1:]...)
+		}
+	}
+	return slice
+}
+
+// find returns the cached account for address if there is a unique match.
+// The exact matching rules are explained by the documentation of accounts.Account.
+// Callers must hold ac.mu.
+func (ac *accountCache) find(a accounts.Account) (accounts.Account, error) {
+	// Limit search to address candidates if possible.
+	matches := ac.all
+	if (a.Address != common.Address{}) {
+		matches = ac.byAddr[a.Address]
+	}
+	if a.URL.Path != "" {
+		// If only the basename is specified, complete the path.
+		if !strings.ContainsRune(a.URL.Path, filepath.Separator) {
+			a.URL.Path = filepath.Join(ac.keydir, a.URL.Path)
+		}
+		for i := range matches {
+			if matches[i].URL == a.URL {
+				return matches[i], nil
+			}
+		}
+		if (a.Address == common.Address{}) {
+			return accounts.Account{}, ErrNoMatch
+		}
+	}
+	switch len(matches) {
+	case 1:
+		return matches[0], nil
+	case 0:
+		return accounts.Account{}, ErrNoMatch
+	default:
+		err := &AmbiguousAddrError{Addr: a.Address, Matches: make([]accounts.Account, len(matches))}
+		copy(err.Matches, matches)
+		sort.Sort(accountsByURL(err.Matches))
+		return accounts.Account{}, err
+	}
+}
+
+func (ac *accountCache) maybeReload() {
+	ac.mu.Lock()
+
+	if ac.watcher.running {
+		ac.mu.Unlock()
+		return // A watcher is running and will keep the cache up-to-date.
+	}
+	if ac.throttle == nil {
+		ac.throttle = time.NewTimer(0)
+	} else {
+		select {
+		case <-ac.throttle.C:
+		default:
+			ac.mu.Unlock()
+			return // The cache was reloaded recently.
+		}
+	}
+	// No watcher running, start it.
+	ac.watcher.start()
+	ac.throttle.Reset(minReloadInterval)
+	ac.mu.Unlock()
+	ac.scanAccounts()
+}
+
+func (ac *accountCache) close() {
+	ac.mu.Lock()
+	ac.watcher.close()
+	if ac.throttle != nil {
+		ac.throttle.Stop()
+	}
+	if ac.notify != nil {
+		close(ac.notify)
+		ac.notify = nil
+	}
+	ac.mu.Unlock()
+}
+
+// scanAccounts checks if any changes have occurred on the filesystem, and
+// updates the account cache accordingly
+func (ac *accountCache) scanAccounts() error {
+	// Scan the entire folder metadata for file changes
+	creates, deletes, updates, err := ac.fileC.scan(ac.keydir)
+	if err != nil {
+		log.Debug("Failed to reload keystore contents", "err", err)
+		return err
+	}
+	if creates.Cardinality() == 0 && deletes.Cardinality() == 0 && updates.Cardinality() == 0 {
+		return nil
+	}
+	// Create a helper method to scan the contents of the key files
+	var (
+		buf = new(bufio.Reader)
+		key struct {
+			Address string `json:"address"`
+		}
+	)
+	readAccount := func(path string) *accounts.Account {
+		fd, err := os.Open(path)
+		if err != nil {
+			log.Trace("Failed to open keystore file", "path", path, "err", err)
+			return nil
+		}
+		defer fd.Close()
+		buf.Reset(fd)
+		// Parse the address.
+		key.Address = ""
+		err = json.NewDecoder(buf).Decode(&key)
+		addr := common.HexToAddress(key.Address)
+		switch {
+		case err != nil:
+			log.Debug("Failed to decode keystore key", "path", path, "err", err)
+		case (addr == common.Address{}):
+			log.Debug("Failed to decode keystore key", "path", path, "err", "missing or zero address")
+		default:
+			return &accounts.Account{
+				Address: addr,
+				URL:     accounts.URL{Scheme: KeyStoreScheme, Path: path},
+			}
+		}
+		return nil
+	}
+	// Process all the file diffs
+	start := time.Now()
+
+	for _, p := range creates.ToSlice() {
+		if a := readAccount(p.(string)); a != nil {
+			ac.add(*a)
+		}
+	}
+	for _, p := range deletes.ToSlice() {
+		ac.deleteByFile(p.(string))
+	}
+	for _, p := range updates.ToSlice() {
+		path := p.(string)
+		ac.deleteByFile(path)
+		if a := readAccount(path); a != nil {
+			ac.add(*a)
+		}
+	}
+	end := time.Now()
+
+	select {
+	case ac.notify <- struct{}{}:
+	default:
+	}
+	log.Trace("Handled keystore changes", "time", end.Sub(start))
+	return nil
+}

accounts/keystore/account_cache_test.go

@@ -0,0 +1,406 @@
+// Copyright 2017 The go-ethereum Authors
+// This file is part of the go-ethereum library.
+//
+// The go-ethereum library is free software: you can redistribute it and/or modify
+// it under the terms of the GNU Lesser General Public License as published by
+// the Free Software Foundation, either version 3 of the License, or
+// (at your option) any later version.
+//
+// The go-ethereum library is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+// GNU Lesser General Public License for more details.
+//
+// You should have received a copy of the GNU Lesser General Public License
+// along with the go-ethereum library. If not, see <http://www.gnu.org/licenses/>.
+
+package keystore
+
+import (
+	"fmt"
+	"io/ioutil"
+	"math/rand"
+	"os"
+	"path/filepath"
+	"reflect"
+	"sort"
+	"testing"
+	"time"
+
+	"github.com/cespare/cp"
+	"github.com/davecgh/go-spew/spew"
+	"github.com/ethereum/go-ethereum/accounts"
+	"github.com/ethereum/go-ethereum/common"
+)
+
+var (
+	cachetestDir, _   = filepath.Abs(filepath.Join("testdata", "keystore"))
+	cachetestAccounts = []accounts.Account{
+		{
+			Address: common.HexToAddress("7ef5a6135f1fd6a02593eedc869c6d41d934aef8"),
+			URL:     accounts.URL{Scheme: KeyStoreScheme, Path: filepath.Join(cachetestDir, "UTC--2016-03-22T12-57-55.920751759Z--7ef5a6135f1fd6a02593eedc869c6d41d934aef8")},
+		},
+		{
+			Address: common.HexToAddress("f466859ead1932d743d622cb74fc058882e8648a"),
+			URL:     accounts.URL{Scheme: KeyStoreScheme, Path: filepath.Join(cachetestDir, "aaa")},
+		},
+		{
+			Address: common.HexToAddress("289d485d9771714cce91d3393d764e1311907acc"),
+			URL:     accounts.URL{Scheme: KeyStoreScheme, Path: filepath.Join(cachetestDir, "zzz")},
+		},
+	}
+)
+
+func TestWatchNewFile(t *testing.T) {
+	t.Parallel()
+
+	dir, ks := tmpKeyStore(t, false)
+	defer os.RemoveAll(dir)
+
+	// Ensure the watcher is started before adding any files.
+	ks.Accounts()
+	time.Sleep(1000 * time.Millisecond)
+
+	// Move in the files.
+	wantAccounts := make([]accounts.Account, len(cachetestAccounts))
+	for i := range cachetestAccounts {
+		wantAccounts[i] = accounts.Account{
+			Address: cachetestAccounts[i].Address,
+			URL:     accounts.URL{Scheme: KeyStoreScheme, Path: filepath.Join(dir, filepath.Base(cachetestAccounts[i].URL.Path))},
+		}
+		if err := cp.CopyFile(wantAccounts[i].URL.Path, cachetestAccounts[i].URL.Path); err != nil {
+			t.Fatal(err)
+		}
+	}
+
+	// ks should see the accounts.
+	var list []accounts.Account
+	for d := 200 * time.Millisecond; d < 5*time.Second; d *= 2 {
+		list = ks.Accounts()
+		if reflect.DeepEqual(list, wantAccounts) {
+			// ks should have also received change notifications
+			select {
+			case <-ks.changes:
+			default:
+				t.Fatalf("wasn't notified of new accounts")
+			}
+			return
+		}
+		time.Sleep(d)
+	}
+	t.Errorf("got %s, want %s", spew.Sdump(list), spew.Sdump(wantAccounts))
+}
+
+func TestWatchNoDir(t *testing.T) {
+	t.Parallel()
+
+	// Create ks but not the directory that it watches.
+	rand.Seed(time.Now().UnixNano())
+	dir := filepath.Join(os.TempDir(), fmt.Sprintf("eth-keystore-watch-test-%d-%d", os.Getpid(), rand.Int()))
+	ks := NewKeyStore(dir, LightScryptN, LightScryptP)
+
+	list := ks.Accounts()
+	if len(list) > 0 {
+		t.Error("initial account list not empty:", list)
+	}
+	time.Sleep(100 * time.Millisecond)
+
+	// Create the directory and copy a key file into it.
+	os.MkdirAll(dir, 0700)
+	defer os.RemoveAll(dir)
+	file := filepath.Join(dir, "aaa")
+	if err := cp.CopyFile(file, cachetestAccounts[0].URL.Path); err != nil {
+		t.Fatal(err)
+	}
+
+	// ks should see the account.
+	wantAccounts := []accounts.Account{cachetestAccounts[0]}
+	wantAccounts[0].URL = accounts.URL{Scheme: KeyStoreScheme, Path: file}
+	for d := 200 * time.Millisecond; d < 8*time.Second; d *= 2 {
+		list = ks.Accounts()
+		if reflect.DeepEqual(list, wantAccounts) {
+			// ks should have also received change notifications
+			select {
+			case <-ks.changes:
+			default:
+				t.Fatalf("wasn't notified of new accounts")
+			}
+			return
+		}
+		time.Sleep(d)
+	}
+	t.Errorf("\ngot  %v\nwant %v", list, wantAccounts)
+}
+
+func TestCacheInitialReload(t *testing.T) {
+	cache, _ := newAccountCache(cachetestDir)
+	accounts := cache.accounts()
+	if !reflect.DeepEqual(accounts, cachetestAccounts) {
+		t.Fatalf("got initial accounts: %swant %s", spew.Sdump(accounts), spew.Sdump(cachetestAccounts))
+	}
+}
+
+func TestCacheAddDeleteOrder(t *testing.T) {
+	cache, _ := newAccountCache("testdata/no-such-dir")
+	cache.watcher.running = true // prevent unexpected reloads
+
+	accs := []accounts.Account{
+		{
+			Address: common.HexToAddress("095e7baea6a6c7c4c2dfeb977efac326af552d87"),
+			URL:     accounts.URL{Scheme: KeyStoreScheme, Path: "-309830980"},
+		},
+		{
+			Address: common.HexToAddress("2cac1adea150210703ba75ed097ddfe24e14f213"),
+			URL:     accounts.URL{Scheme: KeyStoreScheme, Path: "ggg"},
+		},
+		{
+			Address: common.HexToAddress("8bda78331c916a08481428e4b07c96d3e916d165"),
+			URL:     accounts.URL{Scheme: KeyStoreScheme, Path: "zzzzzz-the-very-last-one.keyXXX"},
+		},
+		{
+			Address: common.HexToAddress("d49ff4eeb0b2686ed89c0fc0f2b6ea533ddbbd5e"),
+			URL:     accounts.URL{Scheme: KeyStoreScheme, Path: "SOMETHING.key"},
+		},
+		{
+			Address: common.HexToAddress("7ef5a6135f1fd6a02593eedc869c6d41d934aef8"),
+			URL:     accounts.URL{Scheme: KeyStoreScheme, Path: "UTC--2016-03-22T12-57-55.920751759Z--7ef5a6135f1fd6a02593eedc869c6d41d934aef8"},
+		},
+		{
+			Address: common.HexToAddress("f466859ead1932d743d622cb74fc058882e8648a"),
+			URL:     accounts.URL{Scheme: KeyStoreScheme, Path: "aaa"},
+		},
+		{
+			Address: common.HexToAddress("289d485d9771714cce91d3393d764e1311907acc"),
+			URL:     accounts.URL{Scheme: KeyStoreScheme, Path: "zzz"},
+		},
+	}
+	for _, a := range accs {
+		cache.add(a)
+	}
+	// Add some of them twice to check that they don't get reinserted.
+	cache.add(accs[0])
+	cache.add(accs[2])
+
+	// Check that the account list is sorted by filename.
+	wantAccounts := make([]accounts.Account, len(accs))
+	copy(wantAccounts, accs)
+	sort.Sort(accountsByURL(wantAccounts))
+	list := cache.accounts()
+	if !reflect.DeepEqual(list, wantAccounts) {
+		t.Fatalf("got accounts: %s\nwant %s", spew.Sdump(accs), spew.Sdump(wantAccounts))
+	}
+	for _, a := range accs {
+		if !cache.hasAddress(a.Address) {
+			t.Errorf("expected hasAccount(%x) to return true", a.Address)
+		}
+	}
+	if cache.hasAddress(common.HexToAddress("fd9bd350f08ee3c0c19b85a8e16114a11a60aa4e")) {
+		t.Errorf("expected hasAccount(%x) to return false", common.HexToAddress("fd9bd350f08ee3c0c19b85a8e16114a11a60aa4e"))
+	}
+
+	// Delete a few keys from the cache.
+	for i := 0; i < len(accs); i += 2 {
+		cache.delete(wantAccounts[i])
+	}
+	cache.delete(accounts.Account{Address: common.HexToAddress("fd9bd350f08ee3c0c19b85a8e16114a11a60aa4e"), URL: accounts.URL{Scheme: KeyStoreScheme, Path: "something"}})
+
+	// Check content again after deletion.
+	wantAccountsAfterDelete := []accounts.Account{
+		wantAccounts[1],
+		wantAccounts[3],
+		wantAccounts[5],
+	}
+	list = cache.accounts()
+	if !reflect.DeepEqual(list, wantAccountsAfterDelete) {
+		t.Fatalf("got accounts after delete: %s\nwant %s", spew.Sdump(list), spew.Sdump(wantAccountsAfterDelete))
+	}
+	for _, a := range wantAccountsAfterDelete {
+		if !cache.hasAddress(a.Address) {
+			t.Errorf("expected hasAccount(%x) to return true", a.Address)
+		}
+	}
+	if cache.hasAddress(wantAccounts[0].Address) {
+		t.Errorf("expected hasAccount(%x) to return false", wantAccounts[0].Address)
+	}
+}
+
+func TestCacheFind(t *testing.T) {
+	dir := filepath.Join("testdata", "dir")
+	cache, _ := newAccountCache(dir)
+	cache.watcher.running = true // prevent unexpected reloads
+
+	accs := []accounts.Account{
+		{
+			Address: common.HexToAddress("095e7baea6a6c7c4c2dfeb977efac326af552d87"),
+			URL:     accounts.URL{Scheme: KeyStoreScheme, Path: filepath.Join(dir, "a.key")},
+		},
+		{
+			Address: common.HexToAddress("2cac1adea150210703ba75ed097ddfe24e14f213"),
+			URL:     accounts.URL{Scheme: KeyStoreScheme, Path: filepath.Join(dir, "b.key")},
+		},
+		{
+			Address: common.HexToAddress("d49ff4eeb0b2686ed89c0fc0f2b6ea533ddbbd5e"),
+			URL:     accounts.URL{Scheme: KeyStoreScheme, Path: filepath.Join(dir, "c.key")},
+		},
+		{
+			Address: common.HexToAddress("d49ff4eeb0b2686ed89c0fc0f2b6ea533ddbbd5e"),
+			URL:     accounts.URL{Scheme: KeyStoreScheme, Path: filepath.Join(dir, "c2.key")},
+		},
+	}
+	for _, a := range accs {
+		cache.add(a)
+	}
+
+	nomatchAccount := accounts.Account{
+		Address: common.HexToAddress("f466859ead1932d743d622cb74fc058882e8648a"),
+		URL:     accounts.URL{Scheme: KeyStoreScheme, Path: filepath.Join(dir, "something")},
+	}
+	tests := []struct {
+		Query      accounts.Account
+		WantResult accounts.Account
+		WantError  error
+	}{
+		// by address
+		{Query: accounts.Account{Address: accs[0].Address}, WantResult: accs[0]},
+		// by file
+		{Query: accounts.Account{URL: accs[0].URL}, WantResult: accs[0]},
+		// by basename
+		{Query: accounts.Account{URL: accounts.URL{Scheme: KeyStoreScheme, Path: filepath.Base(accs[0].URL.Path)}}, WantResult: accs[0]},
+		// by file and address
+		{Query: accs[0], WantResult: accs[0]},
+		// ambiguous address, tie resolved by file
+		{Query: accs[2], WantResult: accs[2]},
+		// ambiguous address error
+		{
+			Query: accounts.Account{Address: accs[2].Address},
+			WantError: &AmbiguousAddrError{
+				Addr:    accs[2].Address,
+				Matches: []accounts.Account{accs[2], accs[3]},
+			},
+		},
+		// no match error
+		{Query: nomatchAccount, WantError: ErrNoMatch},
+		{Query: accounts.Account{URL: nomatchAccount.URL}, WantError: ErrNoMatch},
+		{Query: accounts.Account{URL: accounts.URL{Scheme: KeyStoreScheme, Path: filepath.Base(nomatchAccount.URL.Path)}}, WantError: ErrNoMatch},
+		{Query: accounts.Account{Address: nomatchAccount.Address}, WantError: ErrNoMatch},
+	}
+	for i, test := range tests {
+		a, err := cache.find(test.Query)
+		if !reflect.DeepEqual(err, test.WantError) {
+			t.Errorf("test %d: error mismatch for query %v\ngot %q\nwant %q", i, test.Query, err, test.WantError)
+			continue
+		}
+		if a != test.WantResult {
+			t.Errorf("test %d: result mismatch for query %v\ngot %v\nwant %v", i, test.Query, a, test.WantResult)
+			continue
+		}
+	}
+}
+
+func waitForAccounts(wantAccounts []accounts.Account, ks *KeyStore) error {
+	var list []accounts.Account
+	for d := 200 * time.Millisecond; d < 8*time.Second; d *= 2 {
+		list = ks.Accounts()
+		if reflect.DeepEqual(list, wantAccounts) {
+			// ks should have also received change notifications
+			select {
+			case <-ks.changes:
+			default:
+				return fmt.Errorf("wasn't notified of new accounts")
+			}
+			return nil
+		}
+		time.Sleep(d)
+	}
+	return fmt.Errorf("\ngot  %v\nwant %v", list, wantAccounts)
+}
+
+// TestUpdatedKeyfileContents tests that updating the contents of a keystore file
+// is noticed by the watcher, and the account cache is updated accordingly
+func TestUpdatedKeyfileContents(t *testing.T) {
+	t.Parallel()
+
+	// Create a temporary kesytore to test with
+	rand.Seed(time.Now().UnixNano())
+	dir := filepath.Join(os.TempDir(), fmt.Sprintf("eth-keystore-watch-test-%d-%d", os.Getpid(), rand.Int()))
+	ks := NewKeyStore(dir, LightScryptN, LightScryptP)
+
+	list := ks.Accounts()
+	if len(list) > 0 {
+		t.Error("initial account list not empty:", list)
+	}
+	time.Sleep(100 * time.Millisecond)
+
+	// Create the directory and copy a key file into it.
+	os.MkdirAll(dir, 0700)
+	defer os.RemoveAll(dir)
+	file := filepath.Join(dir, "aaa")
+
+	// Place one of our testfiles in there
+	if err := cp.CopyFile(file, cachetestAccounts[0].URL.Path); err != nil {
+		t.Fatal(err)
+	}
+
+	// ks should see the account.
+	wantAccounts := []accounts.Account{cachetestAccounts[0]}
+	wantAccounts[0].URL = accounts.URL{Scheme: KeyStoreScheme, Path: file}
+	if err := waitForAccounts(wantAccounts, ks); err != nil {
+		t.Error(err)
+		return
+	}
+
+	// needed so that modTime of `file` is different to its current value after forceCopyFile
+	time.Sleep(1000 * time.Millisecond)
+
+	// Now replace file contents
+	if err := forceCopyFile(file, cachetestAccounts[1].URL.Path); err != nil {
+		t.Fatal(err)
+		return
+	}
+	wantAccounts = []accounts.Account{cachetestAccounts[1]}
+	wantAccounts[0].URL = accounts.URL{Scheme: KeyStoreScheme, Path: file}
+	if err := waitForAccounts(wantAccounts, ks); err != nil {
+		t.Errorf("First replacement failed")
+		t.Error(err)
+		return
+	}
+
+	// needed so that modTime of `file` is different to its current value after forceCopyFile
+	time.Sleep(1000 * time.Millisecond)
+
+	// Now replace file contents again
+	if err := forceCopyFile(file, cachetestAccounts[2].URL.Path); err != nil {
+		t.Fatal(err)
+		return
+	}
+	wantAccounts = []accounts.Account{cachetestAccounts[2]}
+	wantAccounts[0].URL = accounts.URL{Scheme: KeyStoreScheme, Path: file}
+	if err := waitForAccounts(wantAccounts, ks); err != nil {
+		t.Errorf("Second replacement failed")
+		t.Error(err)
+		return
+	}
+
+	// needed so that modTime of `file` is different to its current value after ioutil.WriteFile
+	time.Sleep(1000 * time.Millisecond)
+
+	// Now replace file contents with crap
+	if err := ioutil.WriteFile(file, []byte("foo"), 0644); err != nil {
+		t.Fatal(err)
+		return
+	}
+	if err := waitForAccounts([]accounts.Account{}, ks); err != nil {
+		t.Errorf("Emptying account file failed")
+		t.Error(err)
+		return
+	}
+}
+
+// forceCopyFile is like cp.CopyFile, but doesn't complain if the destination exists.
+func forceCopyFile(dst, src string) error {
+	data, err := ioutil.ReadFile(src)
+	if err != nil {
+		return err
+	}
+	return ioutil.WriteFile(dst, data, 0644)
+}

accounts/keystore/file_cache.go

@@ -0,0 +1,102 @@
+// Copyright 2017 The go-ethereum Authors
+// This file is part of the go-ethereum library.
+//
+// The go-ethereum library is free software: you can redistribute it and/or modify
+// it under the terms of the GNU Lesser General Public License as published by
+// the Free Software Foundation, either version 3 of the License, or
+// (at your option) any later version.
+//
+// The go-ethereum library is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+// GNU Lesser General Public License for more details.
+//
+// You should have received a copy of the GNU Lesser General Public License
+// along with the go-ethereum library. If not, see <http://www.gnu.org/licenses/>.
+
+package keystore
+
+import (
+	"io/ioutil"
+	"os"
+	"path/filepath"
+	"strings"
+	"sync"
+	"time"
+
+	mapset "github.com/deckarep/golang-set"
+	"github.com/ethereum/go-ethereum/log"
+)
+
+// fileCache is a cache of files seen during scan of keystore.
+type fileCache struct {
+	all     mapset.Set // Set of all files from the keystore folder
+	lastMod time.Time  // Last time instance when a file was modified
+	mu      sync.RWMutex
+}
+
+// scan performs a new scan on the given directory, compares against the already
+// cached filenames, and returns file sets: creates, deletes, updates.
+func (fc *fileCache) scan(keyDir string) (mapset.Set, mapset.Set, mapset.Set, error) {
+	t0 := time.Now()
+
+	// List all the failes from the keystore folder
+	files, err := ioutil.ReadDir(keyDir)
+	if err != nil {
+		return nil, nil, nil, err
+	}
+	t1 := time.Now()
+
+	fc.mu.Lock()
+	defer fc.mu.Unlock()
+
+	// Iterate all the files and gather their metadata
+	all := mapset.NewThreadUnsafeSet()
+	mods := mapset.NewThreadUnsafeSet()
+
+	var newLastMod time.Time
+	for _, fi := range files {
+		path := filepath.Join(keyDir, fi.Name())
+		// Skip any non-key files from the folder
+		if nonKeyFile(fi) {
+			log.Trace("Ignoring file on account scan", "path", path)
+			continue
+		}
+		// Gather the set of all and fresly modified files
+		all.Add(path)
+
+		modified := fi.ModTime()
+		if modified.After(fc.lastMod) {
+			mods.Add(path)
+		}
+		if modified.After(newLastMod) {
+			newLastMod = modified
+		}
+	}
+	t2 := time.Now()
+
+	// Update the tracked files and return the three sets
+	deletes := fc.all.Difference(all)   // Deletes = previous - current
+	creates := all.Difference(fc.all)   // Creates = current - previous
+	updates := mods.Difference(creates) // Updates = modified - creates
+
+	fc.all, fc.lastMod = all, newLastMod
+	t3 := time.Now()
+
+	// Report on the scanning stats and return
+	log.Debug("FS scan times", "list", t1.Sub(t0), "set", t2.Sub(t1), "diff", t3.Sub(t2))
+	return creates, deletes, updates, nil
+}
+
+// nonKeyFile ignores editor backups, hidden files and folders/symlinks.
+func nonKeyFile(fi os.FileInfo) bool {
+	// Skip editor backups and UNIX-style hidden files.
+	if strings.HasSuffix(fi.Name(), "~") || strings.HasPrefix(fi.Name(), ".") {
+		return true
+	}
+	// Skip misc special files, directories (yes, symlinks too).
+	if fi.IsDir() || fi.Mode()&os.ModeType != 0 {
+		return true
+	}
+	return false
+}

accounts/keystore/key.go

@@ -0,0 +1,232 @@
+// Copyright 2014 The go-ethereum Authors
+// This file is part of the go-ethereum library.
+//
+// The go-ethereum library is free software: you can redistribute it and/or modify
+// it under the terms of the GNU Lesser General Public License as published by
+// the Free Software Foundation, either version 3 of the License, or
+// (at your option) any later version.
+//
+// The go-ethereum library is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+// GNU Lesser General Public License for more details.
+//
+// You should have received a copy of the GNU Lesser General Public License
+// along with the go-ethereum library. If not, see <http://www.gnu.org/licenses/>.
+
+package keystore
+
+import (
+	"bytes"
+	"crypto/ecdsa"
+	"encoding/hex"
+	"encoding/json"
+	"fmt"
+	"io"
+	"io/ioutil"
+	"os"
+	"path/filepath"
+	"strings"
+	"time"
+
+	"github.com/ethereum/go-ethereum/accounts"
+	"github.com/ethereum/go-ethereum/common"
+	"github.com/ethereum/go-ethereum/crypto"
+	"github.com/pborman/uuid"
+)
+
+const (
+	version = 3
+)
+
+type Key struct {
+	Id uuid.UUID // Version 4 "random" for unique id not derived from key data
+	// to simplify lookups we also store the address
+	Address common.Address
+	// we only store privkey as pubkey/address can be derived from it
+	// privkey in this struct is always in plaintext
+	PrivateKey *ecdsa.PrivateKey
+}
+
+type keyStore interface {
+	// Loads and decrypts the key from disk.
+	GetKey(addr common.Address, filename string, auth string) (*Key, error)
+	// Writes and encrypts the key.
+	StoreKey(filename string, k *Key, auth string) error
+	// Joins filename with the key directory unless it is already absolute.
+	JoinPath(filename string) string
+}
+
+type plainKeyJSON struct {
+	Address    string `json:"address"`
+	PrivateKey string `json:"privatekey"`
+	Id         string `json:"id"`
+	Version    int    `json:"version"`
+}
+
+type encryptedKeyJSONV3 struct {
+	Address string     `json:"address"`
+	Crypto  CryptoJSON `json:"crypto"`
+	Id      string     `json:"id"`
+	Version int        `json:"version"`
+}
+
+type encryptedKeyJSONV1 struct {
+	Address string     `json:"address"`
+	Crypto  CryptoJSON `json:"crypto"`
+	Id      string     `json:"id"`
+	Version string     `json:"version"`
+}
+
+type CryptoJSON struct {
+	Cipher       string                 `json:"cipher"`
+	CipherText   string                 `json:"ciphertext"`
+	CipherParams cipherparamsJSON       `json:"cipherparams"`
+	KDF          string                 `json:"kdf"`
+	KDFParams    map[string]interface{} `json:"kdfparams"`
+	MAC          string                 `json:"mac"`
+}
+
+type cipherparamsJSON struct {
+	IV string `json:"iv"`
+}
+
+func (k *Key) MarshalJSON() (j []byte, err error) {
+	jStruct := plainKeyJSON{
+		hex.EncodeToString(k.Address[:]),
+		hex.EncodeToString(crypto.FromECDSA(k.PrivateKey)),
+		k.Id.String(),
+		version,
+	}
+	j, err = json.Marshal(jStruct)
+	return j, err
+}
+
+func (k *Key) UnmarshalJSON(j []byte) (err error) {
+	keyJSON := new(plainKeyJSON)
+	err = json.Unmarshal(j, &keyJSON)
+	if err != nil {
+		return err
+	}
+
+	u := new(uuid.UUID)
+	*u = uuid.Parse(keyJSON.Id)
+	k.Id = *u
+	addr, err := hex.DecodeString(keyJSON.Address)
+	if err != nil {
+		return err
+	}
+	privkey, err := crypto.HexToECDSA(keyJSON.PrivateKey)
+	if err != nil {
+		return err
+	}
+
+	k.Address = common.BytesToAddress(addr)
+	k.PrivateKey = privkey
+
+	return nil
+}
+
+func newKeyFromECDSA(privateKeyECDSA *ecdsa.PrivateKey) *Key {
+	id := uuid.NewRandom()
+	key := &Key{
+		Id:         id,
+		Address:    crypto.PubkeyToAddress(privateKeyECDSA.PublicKey),
+		PrivateKey: privateKeyECDSA,
+	}
+	return key
+}
+
+// NewKeyForDirectICAP generates a key whose address fits into < 155 bits so it can fit
+// into the Direct ICAP spec. for simplicity and easier compatibility with other libs, we
+// retry until the first byte is 0.
+func NewKeyForDirectICAP(rand io.Reader) *Key {
+	randBytes := make([]byte, 64)
+	_, err := rand.Read(randBytes)
+	if err != nil {
+		panic("key generation: could not read from random source: " + err.Error())
+	}
+	reader := bytes.NewReader(randBytes)
+	privateKeyECDSA, err := ecdsa.GenerateKey(crypto.S256(), reader)
+	if err != nil {
+		panic("key generation: ecdsa.GenerateKey failed: " + err.Error())
+	}
+	key := newKeyFromECDSA(privateKeyECDSA)
+	if !strings.HasPrefix(key.Address.Hex(), "0x00") {
+		return NewKeyForDirectICAP(rand)
+	}
+	return key
+}
+
+func newKey(rand io.Reader) (*Key, error) {
+	privateKeyECDSA, err := ecdsa.GenerateKey(crypto.S256(), rand)
+	if err != nil {
+		return nil, err
+	}
+	return newKeyFromECDSA(privateKeyECDSA), nil
+}
+
+func storeNewKey(ks keyStore, rand io.Reader, auth string) (*Key, accounts.Account, error) {
+	key, err := newKey(rand)
+	if err != nil {
+		return nil, accounts.Account{}, err
+	}
+	a := accounts.Account{
+		Address: key.Address,
+		URL:     accounts.URL{Scheme: KeyStoreScheme, Path: ks.JoinPath(keyFileName(key.Address))},
+	}
+	if err := ks.StoreKey(a.URL.Path, key, auth); err != nil {
+		zeroKey(key.PrivateKey)
+		return nil, a, err
+	}
+	return key, a, err
+}
+
+func writeTemporaryKeyFile(file string, content []byte) (string, error) {
+	// Create the keystore directory with appropriate permissions
+	// in case it is not present yet.
+	const dirPerm = 0700
+	if err := os.MkdirAll(filepath.Dir(file), dirPerm); err != nil {
+		return "", err
+	}
+	// Atomic write: create a temporary hidden file first
+	// then move it into place. TempFile assigns mode 0600.
+	f, err := ioutil.TempFile(filepath.Dir(file), "."+filepath.Base(file)+".tmp")
+	if err != nil {
+		return "", err
+	}
+	if _, err := f.Write(content); err != nil {
+		f.Close()
+		os.Remove(f.Name())
+		return "", err
+	}
+	f.Close()
+	return f.Name(), nil
+}
+
+func writeKeyFile(file string, content []byte) error {
+	name, err := writeTemporaryKeyFile(file, content)
+	if err != nil {
+		return err
+	}
+	return os.Rename(name, file)
+}
+
+// keyFileName implements the naming convention for keyfiles:
+// UTC--<created_at UTC ISO8601>-<address hex>
+func keyFileName(keyAddr common.Address) string {
+	ts := time.Now().UTC()
+	return fmt.Sprintf("UTC--%s--%s", toISO8601(ts), hex.EncodeToString(keyAddr[:]))
+}
+
+func toISO8601(t time.Time) string {
+	var tz string
+	name, offset := t.Zone()
+	if name == "UTC" {
+		tz = "Z"
+	} else {
+		tz = fmt.Sprintf("%03d00", offset/3600)
+	}
+	return fmt.Sprintf("%04d-%02d-%02dT%02d-%02d-%02d.%09d%s",
+		t.Year(), t.Month(), t.Day(), t.Hour(), t.Minute(), t.Second(), t.Nanosecond(), tz)
+}

accounts/keystore/keystore.go

@@ -0,0 +1,495 @@
+// Copyright 2017 The go-ethereum Authors
+// This file is part of the go-ethereum library.
+//
+// The go-ethereum library is free software: you can redistribute it and/or modify
+// it under the terms of the GNU Lesser General Public License as published by
+// the Free Software Foundation, either version 3 of the License, or
+// (at your option) any later version.
+//
+// The go-ethereum library is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+// GNU Lesser General Public License for more details.
+//
+// You should have received a copy of the GNU Lesser General Public License
+// along with the go-ethereum library. If not, see <http://www.gnu.org/licenses/>.
+
+// Package keystore implements encrypted storage of secp256k1 private keys.
+//
+// Keys are stored as encrypted JSON files according to the Web3 Secret Storage specification.
+// See https://github.com/ethereum/wiki/wiki/Web3-Secret-Storage-Definition for more information.
+package keystore
+
+import (
+	"crypto/ecdsa"
+	crand "crypto/rand"
+	"errors"
+	"fmt"
+	"math/big"
+	"os"
+	"path/filepath"
+	"reflect"
+	"runtime"
+	"sync"
+	"time"
+
+	"github.com/ethereum/go-ethereum/accounts"
+	"github.com/ethereum/go-ethereum/common"
+	"github.com/ethereum/go-ethereum/core/types"
+	"github.com/ethereum/go-ethereum/crypto"
+	"github.com/ethereum/go-ethereum/event"
+)
+
+var (
+	ErrLocked  = accounts.NewAuthNeededError("password or unlock")
+	ErrNoMatch = errors.New("no key for given address or file")
+	ErrDecrypt = errors.New("could not decrypt key with given passphrase")
+)
+
+// KeyStoreType is the reflect type of a keystore backend.
+var KeyStoreType = reflect.TypeOf(&KeyStore{})
+
+// KeyStoreScheme is the protocol scheme prefixing account and wallet URLs.
+const KeyStoreScheme = "keystore"
+
+// Maximum time between wallet refreshes (if filesystem notifications don't work).
+const walletRefreshCycle = 3 * time.Second
+
+// KeyStore manages a key storage directory on disk.
+type KeyStore struct {
+	storage  keyStore                     // Storage backend, might be cleartext or encrypted
+	cache    *accountCache                // In-memory account cache over the filesystem storage
+	changes  chan struct{}                // Channel receiving change notifications from the cache
+	unlocked map[common.Address]*unlocked // Currently unlocked account (decrypted private keys)
+
+	wallets     []accounts.Wallet       // Wallet wrappers around the individual key files
+	updateFeed  event.Feed              // Event feed to notify wallet additions/removals
+	updateScope event.SubscriptionScope // Subscription scope tracking current live listeners
+	updating    bool                    // Whether the event notification loop is running
+
+	mu sync.RWMutex
+}
+
+type unlocked struct {
+	*Key
+	abort chan struct{}
+}
+
+// NewKeyStore creates a keystore for the given directory.
+func NewKeyStore(keydir string, scryptN, scryptP int) *KeyStore {
+	keydir, _ = filepath.Abs(keydir)
+	ks := &KeyStore{storage: &keyStorePassphrase{keydir, scryptN, scryptP, false}}
+	ks.init(keydir)
+	return ks
+}
+
+// NewPlaintextKeyStore creates a keystore for the given directory.
+// Deprecated: Use NewKeyStore.
+func NewPlaintextKeyStore(keydir string) *KeyStore {
+	keydir, _ = filepath.Abs(keydir)
+	ks := &KeyStore{storage: &keyStorePlain{keydir}}
+	ks.init(keydir)
+	return ks
+}
+
+func (ks *KeyStore) init(keydir string) {
+	// Lock the mutex since the account cache might call back with events
+	ks.mu.Lock()
+	defer ks.mu.Unlock()
+
+	// Initialize the set of unlocked keys and the account cache
+	ks.unlocked = make(map[common.Address]*unlocked)
+	ks.cache, ks.changes = newAccountCache(keydir)
+
+	// TODO: In order for this finalizer to work, there must be no references
+	// to ks. addressCache doesn't keep a reference but unlocked keys do,
+	// so the finalizer will not trigger until all timed unlocks have expired.
+	runtime.SetFinalizer(ks, func(m *KeyStore) {
+		m.cache.close()
+	})
+	// Create the initial list of wallets from the cache
+	accs := ks.cache.accounts()
+	ks.wallets = make([]accounts.Wallet, len(accs))
+	for i := 0; i < len(accs); i++ {
+		ks.wallets[i] = &keystoreWallet{account: accs[i], keystore: ks}
+	}
+}
+
+// Wallets implements accounts.Backend, returning all single-key wallets from the
+// keystore directory.
+func (ks *KeyStore) Wallets() []accounts.Wallet {
+	// Make sure the list of wallets is in sync with the account cache
+	ks.refreshWallets()
+
+	ks.mu.RLock()
+	defer ks.mu.RUnlock()
+
+	cpy := make([]accounts.Wallet, len(ks.wallets))
+	copy(cpy, ks.wallets)
+	return cpy
+}
+
+// refreshWallets retrieves the current account list and based on that does any
+// necessary wallet refreshes.
+func (ks *KeyStore) refreshWallets() {
+	// Retrieve the current list of accounts
+	ks.mu.Lock()
+	accs := ks.cache.accounts()
+
+	// Transform the current list of wallets into the new one
+	var (
+		wallets = make([]accounts.Wallet, 0, len(accs))
+		events  []accounts.WalletEvent
+	)
+
+	for _, account := range accs {
+		// Drop wallets while they were in front of the next account
+		for len(ks.wallets) > 0 && ks.wallets[0].URL().Cmp(account.URL) < 0 {
+			events = append(events, accounts.WalletEvent{Wallet: ks.wallets[0], Kind: accounts.WalletDropped})
+			ks.wallets = ks.wallets[1:]
+		}
+		// If there are no more wallets or the account is before the next, wrap new wallet
+		if len(ks.wallets) == 0 || ks.wallets[0].URL().Cmp(account.URL) > 0 {
+			wallet := &keystoreWallet{account: account, keystore: ks}
+
+			events = append(events, accounts.WalletEvent{Wallet: wallet, Kind: accounts.WalletArrived})
+			wallets = append(wallets, wallet)
+			continue
+		}
+		// If the account is the same as the first wallet, keep it
+		if ks.wallets[0].Accounts()[0] == account {
+			wallets = append(wallets, ks.wallets[0])
+			ks.wallets = ks.wallets[1:]
+			continue
+		}
+	}
+	// Drop any leftover wallets and set the new batch
+	for _, wallet := range ks.wallets {
+		events = append(events, accounts.WalletEvent{Wallet: wallet, Kind: accounts.WalletDropped})
+	}
+	ks.wallets = wallets
+	ks.mu.Unlock()
+
+	// Fire all wallet events and return
+	for _, event := range events {
+		ks.updateFeed.Send(event)
+	}
+}
+
+// Subscribe implements accounts.Backend, creating an async subscription to
+// receive notifications on the addition or removal of keystore wallets.
+func (ks *KeyStore) Subscribe(sink chan<- accounts.WalletEvent) event.Subscription {
+	// We need the mutex to reliably start/stop the update loop
+	ks.mu.Lock()
+	defer ks.mu.Unlock()
+
+	// Subscribe the caller and track the subscriber count
+	sub := ks.updateScope.Track(ks.updateFeed.Subscribe(sink))
+
+	// Subscribers require an active notification loop, start it
+	if !ks.updating {
+		ks.updating = true
+		go ks.updater()
+	}
+	return sub
+}
+
+// updater is responsible for maintaining an up-to-date list of wallets stored in
+// the keystore, and for firing wallet addition/removal events. It listens for
+// account change events from the underlying account cache, and also periodically
+// forces a manual refresh (only triggers for systems where the filesystem notifier
+// is not running).
+func (ks *KeyStore) updater() {
+	for {
+		// Wait for an account update or a refresh timeout
+		select {
+		case <-ks.changes:
+		case <-time.After(walletRefreshCycle):
+		}
+		// Run the wallet refresher
+		ks.refreshWallets()
+
+		// If all our subscribers left, stop the updater
+		ks.mu.Lock()
+		if ks.updateScope.Count() == 0 {
+			ks.updating = false
+			ks.mu.Unlock()
+			return
+		}
+		ks.mu.Unlock()
+	}
+}
+
+// HasAddress reports whether a key with the given address is present.
+func (ks *KeyStore) HasAddress(addr common.Address) bool {
+	return ks.cache.hasAddress(addr)
+}
+
+// Accounts returns all key files present in the directory.
+func (ks *KeyStore) Accounts() []accounts.Account {
+	return ks.cache.accounts()
+}
+
+// Delete deletes the key matched by account if the passphrase is correct.
+// If the account contains no filename, the address must match a unique key.
+func (ks *KeyStore) Delete(a accounts.Account, passphrase string) error {
+	// Decrypting the key isn't really necessary, but we do
+	// it anyway to check the password and zero out the key
+	// immediately afterwards.
+	a, key, err := ks.getDecryptedKey(a, passphrase)
+	if key != nil {
+		zeroKey(key.PrivateKey)
+	}
+	if err != nil {
+		return err
+	}
+	// The order is crucial here. The key is dropped from the
+	// cache after the file is gone so that a reload happening in
+	// between won't insert it into the cache again.
+	err = os.Remove(a.URL.Path)
+	if err == nil {
+		ks.cache.delete(a)
+		ks.refreshWallets()
+	}
+	return err
+}
+
+// SignHash calculates a ECDSA signature for the given hash. The produced
+// signature is in the [R || S || V] format where V is 0 or 1.
+func (ks *KeyStore) SignHash(a accounts.Account, hash []byte) ([]byte, error) {
+	// Look up the key to sign with and abort if it cannot be found
+	ks.mu.RLock()
+	defer ks.mu.RUnlock()
+
+	unlockedKey, found := ks.unlocked[a.Address]
+	if !found {
+		return nil, ErrLocked
+	}
+	// Sign the hash using plain ECDSA operations
+	return crypto.Sign(hash, unlockedKey.PrivateKey)
+}
+
+// SignTx signs the given transaction with the requested account.
+func (ks *KeyStore) SignTx(a accounts.Account, tx *types.Transaction, chainID *big.Int) (*types.Transaction, error) {
+	// Look up the key to sign with and abort if it cannot be found
+	ks.mu.RLock()
+	defer ks.mu.RUnlock()
+
+	unlockedKey, found := ks.unlocked[a.Address]
+	if !found {
+		return nil, ErrLocked
+	}
+	// Depending on the presence of the chain ID, sign with EIP155 or homestead
+	if chainID != nil {
+		return types.SignTx(tx, types.NewEIP155Signer(chainID), unlockedKey.PrivateKey)
+	}
+	return types.SignTx(tx, types.HomesteadSigner{}, unlockedKey.PrivateKey)
+}
+
+// SignHashWithPassphrase signs hash if the private key matching the given address
+// can be decrypted with the given passphrase. The produced signature is in the
+// [R || S || V] format where V is 0 or 1.
+func (ks *KeyStore) SignHashWithPassphrase(a accounts.Account, passphrase string, hash []byte) (signature []byte, err error) {
+	_, key, err := ks.getDecryptedKey(a, passphrase)
+	if err != nil {
+		return nil, err
+	}
+	defer zeroKey(key.PrivateKey)
+	return crypto.Sign(hash, key.PrivateKey)
+}
+
+// SignTxWithPassphrase signs the transaction if the private key matching the
+// given address can be decrypted with the given passphrase.
+func (ks *KeyStore) SignTxWithPassphrase(a accounts.Account, passphrase string, tx *types.Transaction, chainID *big.Int) (*types.Transaction, error) {
+	_, key, err := ks.getDecryptedKey(a, passphrase)
+	if err != nil {
+		return nil, err
+	}
+	defer zeroKey(key.PrivateKey)
+
+	// Depending on the presence of the chain ID, sign with EIP155 or homestead
+	if chainID != nil {
+		return types.SignTx(tx, types.NewEIP155Signer(chainID), key.PrivateKey)
+	}
+	return types.SignTx(tx, types.HomesteadSigner{}, key.PrivateKey)
+}
+
+// Unlock unlocks the given account indefinitely.
+func (ks *KeyStore) Unlock(a accounts.Account, passphrase string) error {
+	return ks.TimedUnlock(a, passphrase, 0)
+}
+
+// Lock removes the private key with the given address from memory.
+func (ks *KeyStore) Lock(addr common.Address) error {
+	ks.mu.Lock()
+	if unl, found := ks.unlocked[addr]; found {
+		ks.mu.Unlock()
+		ks.expire(addr, unl, time.Duration(0)*time.Nanosecond)
+	} else {
+		ks.mu.Unlock()
+	}
+	return nil
+}
+
+// TimedUnlock unlocks the given account with the passphrase. The account
+// stays unlocked for the duration of timeout. A timeout of 0 unlocks the account
+// until the program exits. The account must match a unique key file.
+//
+// If the account address is already unlocked for a duration, TimedUnlock extends or
+// shortens the active unlock timeout. If the address was previously unlocked
+// indefinitely the timeout is not altered.
+func (ks *KeyStore) TimedUnlock(a accounts.Account, passphrase string, timeout time.Duration) error {
+	a, key, err := ks.getDecryptedKey(a, passphrase)
+	if err != nil {
+		return err
+	}
+
+	ks.mu.Lock()
+	defer ks.mu.Unlock()
+	u, found := ks.unlocked[a.Address]
+	if found {
+		if u.abort == nil {
+			// The address was unlocked indefinitely, so unlocking
+			// it with a timeout would be confusing.
+			zeroKey(key.PrivateKey)
+			return nil
+		}
+		// Terminate the expire goroutine and replace it below.
+		close(u.abort)
+	}
+	if timeout > 0 {
+		u = &unlocked{Key: key, abort: make(chan struct{})}
+		go ks.expire(a.Address, u, timeout)
+	} else {
+		u = &unlocked{Key: key}
+	}
+	ks.unlocked[a.Address] = u
+	return nil
+}
+
+// Find resolves the given account into a unique entry in the keystore.
+func (ks *KeyStore) Find(a accounts.Account) (accounts.Account, error) {
+	ks.cache.maybeReload()
+	ks.cache.mu.Lock()
+	a, err := ks.cache.find(a)
+	ks.cache.mu.Unlock()
+	return a, err
+}
+
+func (ks *KeyStore) getDecryptedKey(a accounts.Account, auth string) (accounts.Account, *Key, error) {
+	a, err := ks.Find(a)
+	if err != nil {
+		return a, nil, err
+	}
+	key, err := ks.storage.GetKey(a.Address, a.URL.Path, auth)
+	return a, key, err
+}
+
+func (ks *KeyStore) expire(addr common.Address, u *unlocked, timeout time.Duration) {
+	t := time.NewTimer(timeout)
+	defer t.Stop()
+	select {
+	case <-u.abort:
+		// just quit
+	case <-t.C:
+		ks.mu.Lock()
+		// only drop if it's still the same key instance that dropLater
+		// was launched with. we can check that using pointer equality
+		// because the map stores a new pointer every time the key is
+		// unlocked.
+		if ks.unlocked[addr] == u {
+			zeroKey(u.PrivateKey)
+			delete(ks.unlocked, addr)
+		}
+		ks.mu.Unlock()
+	}
+}
+
+// NewAccount generates a new key and stores it into the key directory,
+// encrypting it with the passphrase.
+func (ks *KeyStore) NewAccount(passphrase string) (accounts.Account, error) {
+	_, account, err := storeNewKey(ks.storage, crand.Reader, passphrase)
+	if err != nil {
+		return accounts.Account{}, err
+	}
+	// Add the account to the cache immediately rather
+	// than waiting for file system notifications to pick it up.
+	ks.cache.add(account)
+	ks.refreshWallets()
+	return account, nil
+}
+
+// Export exports as a JSON key, encrypted with newPassphrase.
+func (ks *KeyStore) Export(a accounts.Account, passphrase, newPassphrase string) (keyJSON []byte, err error) {
+	_, key, err := ks.getDecryptedKey(a, passphrase)
+	if err != nil {
+		return nil, err
+	}
+	var N, P int
+	if store, ok := ks.storage.(*keyStorePassphrase); ok {
+		N, P = store.scryptN, store.scryptP
+	} else {
+		N, P = StandardScryptN, StandardScryptP
+	}
+	return EncryptKey(key, newPassphrase, N, P)
+}
+
+// Import stores the given encrypted JSON key into the key directory.
+func (ks *KeyStore) Import(keyJSON []byte, passphrase, newPassphrase string) (accounts.Account, error) {
+	key, err := DecryptKey(keyJSON, passphrase)
+	if key != nil && key.PrivateKey != nil {
+		defer zeroKey(key.PrivateKey)
+	}
+	if err != nil {
+		return accounts.Account{}, err
+	}
+	return ks.importKey(key, newPassphrase)
+}
+
+// ImportECDSA stores the given key into the key directory, encrypting it with the passphrase.
+func (ks *KeyStore) ImportECDSA(priv *ecdsa.PrivateKey, passphrase string) (accounts.Account, error) {
+	key := newKeyFromECDSA(priv)
+	if ks.cache.hasAddress(key.Address) {
+		return accounts.Account{}, fmt.Errorf("account already exists")
+	}
+	return ks.importKey(key, passphrase)
+}
+
+func (ks *KeyStore) importKey(key *Key, passphrase string) (accounts.Account, error) {
+	a := accounts.Account{Address: key.Address, URL: accounts.URL{Scheme: KeyStoreScheme, Path: ks.storage.JoinPath(keyFileName(key.Address))}}
+	if err := ks.storage.StoreKey(a.URL.Path, key, passphrase); err != nil {
+		return accounts.Account{}, err
+	}
+	ks.cache.add(a)
+	ks.refreshWallets()
+	return a, nil
+}
+
+// Update changes the passphrase of an existing account.
+func (ks *KeyStore) Update(a accounts.Account, passphrase, newPassphrase string) error {
+	a, key, err := ks.getDecryptedKey(a, passphrase)
+	if err != nil {
+		return err
+	}
+	return ks.storage.StoreKey(a.URL.Path, key, newPassphrase)
+}
+
+// ImportPreSaleKey decrypts the given Ethereum presale wallet and stores
+// a key file in the key directory. The key file is encrypted with the same passphrase.
+func (ks *KeyStore) ImportPreSaleKey(keyJSON []byte, passphrase string) (accounts.Account, error) {
+	a, _, err := importPreSaleKey(ks.storage, keyJSON, passphrase)
+	if err != nil {
+		return a, err
+	}
+	ks.cache.add(a)
+	ks.refreshWallets()
+	return a, nil
+}
+
+// zeroKey zeroes a private key in memory.
+func zeroKey(k *ecdsa.PrivateKey) {
+	b := k.D.Bits()
+	for i := range b {
+		b[i] = 0
+	}
+}

accounts/keystore/keystore_test.go

@@ -0,0 +1,387 @@
+// Copyright 2017 The go-ethereum Authors
+// This file is part of the go-ethereum library.
+//
+// The go-ethereum library is free software: you can redistribute it and/or modify
+// it under the terms of the GNU Lesser General Public License as published by
+// the Free Software Foundation, either version 3 of the License, or
+// (at your option) any later version.
+//
+// The go-ethereum library is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+// GNU Lesser General Public License for more details.
+//
+// You should have received a copy of the GNU Lesser General Public License
+// along with the go-ethereum library. If not, see <http://www.gnu.org/licenses/>.
+
+package keystore
+
+import (
+	"io/ioutil"
+	"math/rand"
+	"os"
+	"runtime"
+	"sort"
+	"strings"
+	"testing"
+	"time"
+
+	"github.com/ethereum/go-ethereum/accounts"
+	"github.com/ethereum/go-ethereum/common"
+	"github.com/ethereum/go-ethereum/event"
+)
+
+var testSigData = make([]byte, 32)
+
+func TestKeyStore(t *testing.T) {
+	dir, ks := tmpKeyStore(t, true)
+	defer os.RemoveAll(dir)
+
+	a, err := ks.NewAccount("foo")
+	if err != nil {
+		t.Fatal(err)
+	}
+	if !strings.HasPrefix(a.URL.Path, dir) {
+		t.Errorf("account file %s doesn't have dir prefix", a.URL)
+	}
+	stat, err := os.Stat(a.URL.Path)
+	if err != nil {
+		t.Fatalf("account file %s doesn't exist (%v)", a.URL, err)
+	}
+	if runtime.GOOS != "windows" && stat.Mode() != 0600 {
+		t.Fatalf("account file has wrong mode: got %o, want %o", stat.Mode(), 0600)
+	}
+	if !ks.HasAddress(a.Address) {
+		t.Errorf("HasAccount(%x) should've returned true", a.Address)
+	}
+	if err := ks.Update(a, "foo", "bar"); err != nil {
+		t.Errorf("Update error: %v", err)
+	}
+	if err := ks.Delete(a, "bar"); err != nil {
+		t.Errorf("Delete error: %v", err)
+	}
+	if common.FileExist(a.URL.Path) {
+		t.Errorf("account file %s should be gone after Delete", a.URL)
+	}
+	if ks.HasAddress(a.Address) {
+		t.Errorf("HasAccount(%x) should've returned true after Delete", a.Address)
+	}
+}
+
+func TestSign(t *testing.T) {
+	dir, ks := tmpKeyStore(t, true)
+	defer os.RemoveAll(dir)
+
+	pass := "" // not used but required by API
+	a1, err := ks.NewAccount(pass)
+	if err != nil {
+		t.Fatal(err)
+	}
+	if err := ks.Unlock(a1, ""); err != nil {
+		t.Fatal(err)
+	}
+	if _, err := ks.SignHash(accounts.Account{Address: a1.Address}, testSigData); err != nil {
+		t.Fatal(err)
+	}
+}
+
+func TestSignWithPassphrase(t *testing.T) {
+	dir, ks := tmpKeyStore(t, true)
+	defer os.RemoveAll(dir)
+
+	pass := "passwd"
+	acc, err := ks.NewAccount(pass)
+	if err != nil {
+		t.Fatal(err)
+	}
+
+	if _, unlocked := ks.unlocked[acc.Address]; unlocked {
+		t.Fatal("expected account to be locked")
+	}
+
+	_, err = ks.SignHashWithPassphrase(acc, pass, testSigData)
+	if err != nil {
+		t.Fatal(err)
+	}
+
+	if _, unlocked := ks.unlocked[acc.Address]; unlocked {
+		t.Fatal("expected account to be locked")
+	}
+
+	if _, err = ks.SignHashWithPassphrase(acc, "invalid passwd", testSigData); err == nil {
+		t.Fatal("expected SignHashWithPassphrase to fail with invalid password")
+	}
+}
+
+func TestTimedUnlock(t *testing.T) {
+	dir, ks := tmpKeyStore(t, true)
+	defer os.RemoveAll(dir)
+
+	pass := "foo"
+	a1, err := ks.NewAccount(pass)
+	if err != nil {
+		t.Fatal(err)
+	}
+
+	// Signing without passphrase fails because account is locked
+	_, err = ks.SignHash(accounts.Account{Address: a1.Address}, testSigData)
+	if err != ErrLocked {
+		t.Fatal("Signing should've failed with ErrLocked before unlocking, got ", err)
+	}
+
+	// Signing with passphrase works
+	if err = ks.TimedUnlock(a1, pass, 100*time.Millisecond); err != nil {
+		t.Fatal(err)
+	}
+
+	// Signing without passphrase works because account is temp unlocked
+	_, err = ks.SignHash(accounts.Account{Address: a1.Address}, testSigData)
+	if err != nil {
+		t.Fatal("Signing shouldn't return an error after unlocking, got ", err)
+	}
+
+	// Signing fails again after automatic locking
+	time.Sleep(250 * time.Millisecond)
+	_, err = ks.SignHash(accounts.Account{Address: a1.Address}, testSigData)
+	if err != ErrLocked {
+		t.Fatal("Signing should've failed with ErrLocked timeout expired, got ", err)
+	}
+}
+
+func TestOverrideUnlock(t *testing.T) {
+	dir, ks := tmpKeyStore(t, false)
+	defer os.RemoveAll(dir)
+
+	pass := "foo"
+	a1, err := ks.NewAccount(pass)
+	if err != nil {
+		t.Fatal(err)
+	}
+
+	// Unlock indefinitely.
+	if err = ks.TimedUnlock(a1, pass, 5*time.Minute); err != nil {
+		t.Fatal(err)
+	}
+
+	// Signing without passphrase works because account is temp unlocked
+	_, err = ks.SignHash(accounts.Account{Address: a1.Address}, testSigData)
+	if err != nil {
+		t.Fatal("Signing shouldn't return an error after unlocking, got ", err)
+	}
+
+	// reset unlock to a shorter period, invalidates the previous unlock
+	if err = ks.TimedUnlock(a1, pass, 100*time.Millisecond); err != nil {
+		t.Fatal(err)
+	}
+
+	// Signing without passphrase still works because account is temp unlocked
+	_, err = ks.SignHash(accounts.Account{Address: a1.Address}, testSigData)
+	if err != nil {
+		t.Fatal("Signing shouldn't return an error after unlocking, got ", err)
+	}
+
+	// Signing fails again after automatic locking
+	time.Sleep(250 * time.Millisecond)
+	_, err = ks.SignHash(accounts.Account{Address: a1.Address}, testSigData)
+	if err != ErrLocked {
+		t.Fatal("Signing should've failed with ErrLocked timeout expired, got ", err)
+	}
+}
+
+// This test should fail under -race if signing races the expiration goroutine.
+func TestSignRace(t *testing.T) {
+	dir, ks := tmpKeyStore(t, false)
+	defer os.RemoveAll(dir)
+
+	// Create a test account.
+	a1, err := ks.NewAccount("")
+	if err != nil {
+		t.Fatal("could not create the test account", err)
+	}
+
+	if err := ks.TimedUnlock(a1, "", 15*time.Millisecond); err != nil {
+		t.Fatal("could not unlock the test account", err)
+	}
+	end := time.Now().Add(500 * time.Millisecond)
+	for time.Now().Before(end) {
+		if _, err := ks.SignHash(accounts.Account{Address: a1.Address}, testSigData); err == ErrLocked {
+			return
+		} else if err != nil {
+			t.Errorf("Sign error: %v", err)
+			return
+		}
+		time.Sleep(1 * time.Millisecond)
+	}
+	t.Errorf("Account did not lock within the timeout")
+}
+
+// Tests that the wallet notifier loop starts and stops correctly based on the
+// addition and removal of wallet event subscriptions.
+func TestWalletNotifierLifecycle(t *testing.T) {
+	// Create a temporary kesytore to test with
+	dir, ks := tmpKeyStore(t, false)
+	defer os.RemoveAll(dir)
+
+	// Ensure that the notification updater is not running yet
+	time.Sleep(250 * time.Millisecond)
+	ks.mu.RLock()
+	updating := ks.updating
+	ks.mu.RUnlock()
+
+	if updating {
+		t.Errorf("wallet notifier running without subscribers")
+	}
+	// Subscribe to the wallet feed and ensure the updater boots up
+	updates := make(chan accounts.WalletEvent)
+
+	subs := make([]event.Subscription, 2)
+	for i := 0; i < len(subs); i++ {
+		// Create a new subscription
+		subs[i] = ks.Subscribe(updates)
+
+		// Ensure the notifier comes online
+		time.Sleep(250 * time.Millisecond)
+		ks.mu.RLock()
+		updating = ks.updating
+		ks.mu.RUnlock()
+
+		if !updating {
+			t.Errorf("sub %d: wallet notifier not running after subscription", i)
+		}
+	}
+	// Unsubscribe and ensure the updater terminates eventually
+	for i := 0; i < len(subs); i++ {
+		// Close an existing subscription
+		subs[i].Unsubscribe()
+
+		// Ensure the notifier shuts down at and only at the last close
+		for k := 0; k < int(walletRefreshCycle/(250*time.Millisecond))+2; k++ {
+			ks.mu.RLock()
+			updating = ks.updating
+			ks.mu.RUnlock()
+
+			if i < len(subs)-1 && !updating {
+				t.Fatalf("sub %d: event notifier stopped prematurely", i)
+			}
+			if i == len(subs)-1 && !updating {
+				return
+			}
+			time.Sleep(250 * time.Millisecond)
+		}
+	}
+	t.Errorf("wallet notifier didn't terminate after unsubscribe")
+}
+
+type walletEvent struct {
+	accounts.WalletEvent
+	a accounts.Account
+}
+
+// Tests that wallet notifications and correctly fired when accounts are added
+// or deleted from the keystore.
+func TestWalletNotifications(t *testing.T) {
+	dir, ks := tmpKeyStore(t, false)
+	defer os.RemoveAll(dir)
+
+	// Subscribe to the wallet feed and collect events.
+	var (
+		events  []walletEvent
+		updates = make(chan accounts.WalletEvent)
+		sub     = ks.Subscribe(updates)
+	)
+	defer sub.Unsubscribe()
+	go func() {
+		for {
+			select {
+			case ev := <-updates:
+				events = append(events, walletEvent{ev, ev.Wallet.Accounts()[0]})
+			case <-sub.Err():
+				close(updates)
+				return
+			}
+		}
+	}()
+
+	// Randomly add and remove accounts.
+	var (
+		live       = make(map[common.Address]accounts.Account)
+		wantEvents []walletEvent
+	)
+	for i := 0; i < 1024; i++ {
+		if create := len(live) == 0 || rand.Int()%4 > 0; create {
+			// Add a new account and ensure wallet notifications arrives
+			account, err := ks.NewAccount("")
+			if err != nil {
+				t.Fatalf("failed to create test account: %v", err)
+			}
+			live[account.Address] = account
+			wantEvents = append(wantEvents, walletEvent{accounts.WalletEvent{Kind: accounts.WalletArrived}, account})
+		} else {
+			// Delete a random account.
+			var account accounts.Account
+			for _, a := range live {
+				account = a
+				break
+			}
+			if err := ks.Delete(account, ""); err != nil {
+				t.Fatalf("failed to delete test account: %v", err)
+			}
+			delete(live, account.Address)
+			wantEvents = append(wantEvents, walletEvent{accounts.WalletEvent{Kind: accounts.WalletDropped}, account})
+		}
+	}
+
+	// Shut down the event collector and check events.
+	sub.Unsubscribe()
+	<-updates
+	checkAccounts(t, live, ks.Wallets())
+	checkEvents(t, wantEvents, events)
+}
+
+// checkAccounts checks that all known live accounts are present in the wallet list.
+func checkAccounts(t *testing.T, live map[common.Address]accounts.Account, wallets []accounts.Wallet) {
+	if len(live) != len(wallets) {
+		t.Errorf("wallet list doesn't match required accounts: have %d, want %d", len(wallets), len(live))
+		return
+	}
+	liveList := make([]accounts.Account, 0, len(live))
+	for _, account := range live {
+		liveList = append(liveList, account)
+	}
+	sort.Sort(accountsByURL(liveList))
+	for j, wallet := range wallets {
+		if accs := wallet.Accounts(); len(accs) != 1 {
+			t.Errorf("wallet %d: contains invalid number of accounts: have %d, want 1", j, len(accs))
+		} else if accs[0] != liveList[j] {
+			t.Errorf("wallet %d: account mismatch: have %v, want %v", j, accs[0], liveList[j])
+		}
+	}
+}
+
+// checkEvents checks that all events in 'want' are present in 'have'. Events may be present multiple times.
+func checkEvents(t *testing.T, want []walletEvent, have []walletEvent) {
+	for _, wantEv := range want {
+		nmatch := 0
+		for ; len(have) > 0; nmatch++ {
+			if have[0].Kind != wantEv.Kind || have[0].a != wantEv.a {
+				break
+			}
+			have = have[1:]
+		}
+		if nmatch == 0 {
+			t.Fatalf("can't find event with Kind=%v for %x", wantEv.Kind, wantEv.a.Address)
+		}
+	}
+}
+
+func tmpKeyStore(t *testing.T, encrypted bool) (string, *KeyStore) {
+	d, err := ioutil.TempDir("", "eth-keystore-test")
+	if err != nil {
+		t.Fatal(err)
+	}
+	new := NewPlaintextKeyStore
+	if encrypted {
+		new = func(kd string) *KeyStore { return NewKeyStore(kd, veryLightScryptN, veryLightScryptP) }
+	}
+	return d, new(d)
+}

accounts/keystore/passphrase.go

@@ -0,0 +1,356 @@
+// Copyright 2014 The go-ethereum Authors
+// This file is part of the go-ethereum library.
+//
+// The go-ethereum library is free software: you can redistribute it and/or modify
+// it under the terms of the GNU Lesser General Public License as published by
+// the Free Software Foundation, either version 3 of the License, or
+// (at your option) any later version.
+//
+// The go-ethereum library is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+// GNU Lesser General Public License for more details.
+//
+// You should have received a copy of the GNU Lesser General Public License
+// along with the go-ethereum library. If not, see <http://www.gnu.org/licenses/>.
+
+/*
+
+This key store behaves as KeyStorePlain with the difference that
+the private key is encrypted and on disk uses another JSON encoding.
+
+The crypto is documented at https://github.com/ethereum/wiki/wiki/Web3-Secret-Storage-Definition
+
+*/
+
+package keystore
+
+import (
+	"bytes"
+	"crypto/aes"
+	"crypto/rand"
+	"crypto/sha256"
+	"encoding/hex"
+	"encoding/json"
+	"fmt"
+	"io"
+	"io/ioutil"
+	"os"
+	"path/filepath"
+
+	"github.com/ethereum/go-ethereum/accounts"
+	"github.com/ethereum/go-ethereum/common"
+	"github.com/ethereum/go-ethereum/common/math"
+	"github.com/ethereum/go-ethereum/crypto"
+	"github.com/pborman/uuid"
+	"golang.org/x/crypto/pbkdf2"
+	"golang.org/x/crypto/scrypt"
+)
+
+const (
+	keyHeaderKDF = "scrypt"
+
+	// StandardScryptN is the N parameter of Scrypt encryption algorithm, using 256MB
+	// memory and taking approximately 1s CPU time on a modern processor.
+	StandardScryptN = 1 << 18
+
+	// StandardScryptP is the P parameter of Scrypt encryption algorithm, using 256MB
+	// memory and taking approximately 1s CPU time on a modern processor.
+	StandardScryptP = 1
+
+	// LightScryptN is the N parameter of Scrypt encryption algorithm, using 4MB
+	// memory and taking approximately 100ms CPU time on a modern processor.
+	LightScryptN = 1 << 12
+
+	// LightScryptP is the P parameter of Scrypt encryption algorithm, using 4MB
+	// memory and taking approximately 100ms CPU time on a modern processor.
+	LightScryptP = 6
+
+	scryptR     = 8
+	scryptDKLen = 32
+)
+
+type keyStorePassphrase struct {
+	keysDirPath string
+	scryptN     int
+	scryptP     int
+	// skipKeyFileVerification disables the security-feature which does
+	// reads and decrypts any newly created keyfiles. This should be 'false' in all
+	// cases except tests -- setting this to 'true' is not recommended.
+	skipKeyFileVerification bool
+}
+
+func (ks keyStorePassphrase) GetKey(addr common.Address, filename, auth string) (*Key, error) {
+	// Load the key from the keystore and decrypt its contents
+	keyjson, err := ioutil.ReadFile(filename)
+	if err != nil {
+		return nil, err
+	}
+	key, err := DecryptKey(keyjson, auth)
+	if err != nil {
+		return nil, err
+	}
+	// Make sure we're really operating on the requested key (no swap attacks)
+	if key.Address != addr {
+		return nil, fmt.Errorf("key content mismatch: have account %x, want %x", key.Address, addr)
+	}
+	return key, nil
+}
+
+// StoreKey generates a key, encrypts with 'auth' and stores in the given directory
+func StoreKey(dir, auth string, scryptN, scryptP int) (accounts.Account, error) {
+	_, a, err := storeNewKey(&keyStorePassphrase{dir, scryptN, scryptP, false}, rand.Reader, auth)
+	return a, err
+}
+
+func (ks keyStorePassphrase) StoreKey(filename string, key *Key, auth string) error {
+	keyjson, err := EncryptKey(key, auth, ks.scryptN, ks.scryptP)
+	if err != nil {
+		return err
+	}
+	// Write into temporary file
+	tmpName, err := writeTemporaryKeyFile(filename, keyjson)
+	if err != nil {
+		return err
+	}
+	if !ks.skipKeyFileVerification {
+		// Verify that we can decrypt the file with the given password.
+		_, err = ks.GetKey(key.Address, tmpName, auth)
+		if err != nil {
+			msg := "An error was encountered when saving and verifying the keystore file. \n" +
+				"This indicates that the keystore is corrupted. \n" +
+				"The corrupted file is stored at \n%v\n" +
+				"Please file a ticket at:\n\n" +
+				"https://github.com/ethereum/go-ethereum/issues." +
+				"The error was : %s"
+			return fmt.Errorf(msg, tmpName, err)
+		}
+	}
+	return os.Rename(tmpName, filename)
+}
+
+func (ks keyStorePassphrase) JoinPath(filename string) string {
+	if filepath.IsAbs(filename) {
+		return filename
+	}
+	return filepath.Join(ks.keysDirPath, filename)
+}
+
+// Encryptdata encrypts the data given as 'data' with the password 'auth'.
+func EncryptDataV3(data, auth []byte, scryptN, scryptP int) (CryptoJSON, error) {
+
+	salt := make([]byte, 32)
+	if _, err := io.ReadFull(rand.Reader, salt); err != nil {
+		panic("reading from crypto/rand failed: " + err.Error())
+	}
+	derivedKey, err := scrypt.Key(auth, salt, scryptN, scryptR, scryptP, scryptDKLen)
+	if err != nil {
+		return CryptoJSON{}, err
+	}
+	encryptKey := derivedKey[:16]
+
+	iv := make([]byte, aes.BlockSize) // 16
+	if _, err := io.ReadFull(rand.Reader, iv); err != nil {
+		panic("reading from crypto/rand failed: " + err.Error())
+	}
+	cipherText, err := aesCTRXOR(encryptKey, data, iv)
+	if err != nil {
+		return CryptoJSON{}, err
+	}
+	mac := crypto.Keccak256(derivedKey[16:32], cipherText)
+
+	scryptParamsJSON := make(map[string]interface{}, 5)
+	scryptParamsJSON["n"] = scryptN
+	scryptParamsJSON["r"] = scryptR
+	scryptParamsJSON["p"] = scryptP
+	scryptParamsJSON["dklen"] = scryptDKLen
+	scryptParamsJSON["salt"] = hex.EncodeToString(salt)
+	cipherParamsJSON := cipherparamsJSON{
+		IV: hex.EncodeToString(iv),
+	}
+
+	cryptoStruct := CryptoJSON{
+		Cipher:       "aes-128-ctr",
+		CipherText:   hex.EncodeToString(cipherText),
+		CipherParams: cipherParamsJSON,
+		KDF:          keyHeaderKDF,
+		KDFParams:    scryptParamsJSON,
+		MAC:          hex.EncodeToString(mac),
+	}
+	return cryptoStruct, nil
+}
+
+// EncryptKey encrypts a key using the specified scrypt parameters into a json
+// blob that can be decrypted later on.
+func EncryptKey(key *Key, auth string, scryptN, scryptP int) ([]byte, error) {
+	keyBytes := math.PaddedBigBytes(key.PrivateKey.D, 32)
+	cryptoStruct, err := EncryptDataV3(keyBytes, []byte(auth), scryptN, scryptP)
+	if err != nil {
+		return nil, err
+	}
+	encryptedKeyJSONV3 := encryptedKeyJSONV3{
+		hex.EncodeToString(key.Address[:]),
+		cryptoStruct,
+		key.Id.String(),
+		version,
+	}
+	return json.Marshal(encryptedKeyJSONV3)
+}
+
+// DecryptKey decrypts a key from a json blob, returning the private key itself.
+func DecryptKey(keyjson []byte, auth string) (*Key, error) {
+	// Parse the json into a simple map to fetch the key version
+	m := make(map[string]interface{})
+	if err := json.Unmarshal(keyjson, &m); err != nil {
+		return nil, err
+	}
+	// Depending on the version try to parse one way or another
+	var (
+		keyBytes, keyId []byte
+		err             error
+	)
+	if version, ok := m["version"].(string); ok && version == "1" {
+		k := new(encryptedKeyJSONV1)
+		if err := json.Unmarshal(keyjson, k); err != nil {
+			return nil, err
+		}
+		keyBytes, keyId, err = decryptKeyV1(k, auth)
+	} else {
+		k := new(encryptedKeyJSONV3)
+		if err := json.Unmarshal(keyjson, k); err != nil {
+			return nil, err
+		}
+		keyBytes, keyId, err = decryptKeyV3(k, auth)
+	}
+	// Handle any decryption errors and return the key
+	if err != nil {
+		return nil, err
+	}
+	key := crypto.ToECDSAUnsafe(keyBytes)
+
+	return &Key{
+		Id:         uuid.UUID(keyId),
+		Address:    crypto.PubkeyToAddress(key.PublicKey),
+		PrivateKey: key,
+	}, nil
+}
+
+func DecryptDataV3(cryptoJson CryptoJSON, auth string) ([]byte, error) {
+	if cryptoJson.Cipher != "aes-128-ctr" {
+		return nil, fmt.Errorf("Cipher not supported: %v", cryptoJson.Cipher)
+	}
+	mac, err := hex.DecodeString(cryptoJson.MAC)
+	if err != nil {
+		return nil, err
+	}
+
+	iv, err := hex.DecodeString(cryptoJson.CipherParams.IV)
+	if err != nil {
+		return nil, err
+	}
+
+	cipherText, err := hex.DecodeString(cryptoJson.CipherText)
+	if err != nil {
+		return nil, err
+	}
+
+	derivedKey, err := getKDFKey(cryptoJson, auth)
+	if err != nil {
+		return nil, err
+	}
+
+	calculatedMAC := crypto.Keccak256(derivedKey[16:32], cipherText)
+	if !bytes.Equal(calculatedMAC, mac) {
+		return nil, ErrDecrypt
+	}
+
+	plainText, err := aesCTRXOR(derivedKey[:16], cipherText, iv)
+	if err != nil {
+		return nil, err
+	}
+	return plainText, err
+}
+
+func decryptKeyV3(keyProtected *encryptedKeyJSONV3, auth string) (keyBytes []byte, keyId []byte, err error) {
+	if keyProtected.Version != version {
+		return nil, nil, fmt.Errorf("Version not supported: %v", keyProtected.Version)
+	}
+	keyId = uuid.Parse(keyProtected.Id)
+	plainText, err := DecryptDataV3(keyProtected.Crypto, auth)
+	if err != nil {
+		return nil, nil, err
+	}
+	return plainText, keyId, err
+}
+
+func decryptKeyV1(keyProtected *encryptedKeyJSONV1, auth string) (keyBytes []byte, keyId []byte, err error) {
+	keyId = uuid.Parse(keyProtected.Id)
+	mac, err := hex.DecodeString(keyProtected.Crypto.MAC)
+	if err != nil {
+		return nil, nil, err
+	}
+
+	iv, err := hex.DecodeString(keyProtected.Crypto.CipherParams.IV)
+	if err != nil {
+		return nil, nil, err
+	}
+
+	cipherText, err := hex.DecodeString(keyProtected.Crypto.CipherText)
+	if err != nil {
+		return nil, nil, err
+	}
+
+	derivedKey, err := getKDFKey(keyProtected.Crypto, auth)
+	if err != nil {
+		return nil, nil, err
+	}
+
+	calculatedMAC := crypto.Keccak256(derivedKey[16:32], cipherText)
+	if !bytes.Equal(calculatedMAC, mac) {
+		return nil, nil, ErrDecrypt
+	}
+
+	plainText, err := aesCBCDecrypt(crypto.Keccak256(derivedKey[:16])[:16], cipherText, iv)
+	if err != nil {
+		return nil, nil, err
+	}
+	return plainText, keyId, err
+}
+
+func getKDFKey(cryptoJSON CryptoJSON, auth string) ([]byte, error) {
+	authArray := []byte(auth)
+	salt, err := hex.DecodeString(cryptoJSON.KDFParams["salt"].(string))
+	if err != nil {
+		return nil, err
+	}
+	dkLen := ensureInt(cryptoJSON.KDFParams["dklen"])
+
+	if cryptoJSON.KDF == keyHeaderKDF {
+		n := ensureInt(cryptoJSON.KDFParams["n"])
+		r := ensureInt(cryptoJSON.KDFParams["r"])
+		p := ensureInt(cryptoJSON.KDFParams["p"])
+		return scrypt.Key(authArray, salt, n, r, p, dkLen)
+
+	} else if cryptoJSON.KDF == "pbkdf2" {
+		c := ensureInt(cryptoJSON.KDFParams["c"])
+		prf := cryptoJSON.KDFParams["prf"].(string)
+		if prf != "hmac-sha256" {
+			return nil, fmt.Errorf("Unsupported PBKDF2 PRF: %s", prf)
+		}
+		key := pbkdf2.Key(authArray, salt, c, dkLen, sha256.New)
+		return key, nil
+	}
+
+	return nil, fmt.Errorf("Unsupported KDF: %s", cryptoJSON.KDF)
+}
+
+// TODO: can we do without this when unmarshalling dynamic JSON?
+// why do integers in KDF params end up as float64 and not int after
+// unmarshal?
+func ensureInt(x interface{}) int {
+	res, ok := x.(int)
+	if !ok {
+		res = int(x.(float64))
+	}
+	return res
+}

accounts/keystore/passphrase_test.go

@@ -0,0 +1,60 @@
+// Copyright 2016 The go-ethereum Authors
+// This file is part of the go-ethereum library.
+//
+// The go-ethereum library is free software: you can redistribute it and/or modify
+// it under the terms of the GNU Lesser General Public License as published by
+// the Free Software Foundation, either version 3 of the License, or
+// (at your option) any later version.
+//
+// The go-ethereum library is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+// GNU Lesser General Public License for more details.
+//
+// You should have received a copy of the GNU Lesser General Public License
+// along with the go-ethereum library. If not, see <http://www.gnu.org/licenses/>.
+
+package keystore
+
+import (
+	"io/ioutil"
+	"testing"
+
+	"github.com/ethereum/go-ethereum/common"
+)
+
+const (
+	veryLightScryptN = 2
+	veryLightScryptP = 1
+)
+
+// Tests that a json key file can be decrypted and encrypted in multiple rounds.
+func TestKeyEncryptDecrypt(t *testing.T) {
+	keyjson, err := ioutil.ReadFile("testdata/very-light-scrypt.json")
+	if err != nil {
+		t.Fatal(err)
+	}
+	password := ""
+	address := common.HexToAddress("45dea0fb0bba44f4fcf290bba71fd57d7117cbb8")
+
+	// Do a few rounds of decryption and encryption
+	for i := 0; i < 3; i++ {
+		// Try a bad password first
+		if _, err := DecryptKey(keyjson, password+"bad"); err == nil {
+			t.Errorf("test %d: json key decrypted with bad password", i)
+		}
+		// Decrypt with the correct password
+		key, err := DecryptKey(keyjson, password)
+		if err != nil {
+			t.Fatalf("test %d: json key failed to decrypt: %v", i, err)
+		}
+		if key.Address != address {
+			t.Errorf("test %d: key address mismatch: have %x, want %x", i, key.Address, address)
+		}
+		// Recrypt with a new password and start over
+		password += "new data appended"
+		if keyjson, err = EncryptKey(key, password, veryLightScryptN, veryLightScryptP); err != nil {
+			t.Errorf("test %d: failed to recrypt key %v", i, err)
+		}
+	}
+}

accounts/keystore/plain.go

@@ -0,0 +1,61 @@
+// Copyright 2015 The go-ethereum Authors
+// This file is part of the go-ethereum library.
+//
+// The go-ethereum library is free software: you can redistribute it and/or modify
+// it under the terms of the GNU Lesser General Public License as published by
+// the Free Software Foundation, either version 3 of the License, or
+// (at your option) any later version.
+//
+// The go-ethereum library is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+// GNU Lesser General Public License for more details.
+//
+// You should have received a copy of the GNU Lesser General Public License
+// along with the go-ethereum library. If not, see <http://www.gnu.org/licenses/>.
+
+package keystore
+
+import (
+	"encoding/json"
+	"fmt"
+	"os"
+	"path/filepath"
+
+	"github.com/ethereum/go-ethereum/common"
+)
+
+type keyStorePlain struct {
+	keysDirPath string
+}
+
+func (ks keyStorePlain) GetKey(addr common.Address, filename, auth string) (*Key, error) {
+	fd, err := os.Open(filename)
+	if err != nil {
+		return nil, err
+	}
+	defer fd.Close()
+	key := new(Key)
+	if err := json.NewDecoder(fd).Decode(key); err != nil {
+		return nil, err
+	}
+	if key.Address != addr {
+		return nil, fmt.Errorf("key content mismatch: have address %x, want %x", key.Address, addr)
+	}
+	return key, nil
+}
+
+func (ks keyStorePlain) StoreKey(filename string, key *Key, auth string) error {
+	content, err := json.Marshal(key)
+	if err != nil {
+		return err
+	}
+	return writeKeyFile(filename, content)
+}
+
+func (ks keyStorePlain) JoinPath(filename string) string {
+	if filepath.IsAbs(filename) {
+		return filename
+	}
+	return filepath.Join(ks.keysDirPath, filename)
+}

accounts/keystore/plain_test.go

@@ -0,0 +1,266 @@
+// Copyright 2014 The go-ethereum Authors
+// This file is part of the go-ethereum library.
+//
+// The go-ethereum library is free software: you can redistribute it and/or modify
+// it under the terms of the GNU Lesser General Public License as published by
+// the Free Software Foundation, either version 3 of the License, or
+// (at your option) any later version.
+//
+// The go-ethereum library is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+// GNU Lesser General Public License for more details.
+//
+// You should have received a copy of the GNU Lesser General Public License
+// along with the go-ethereum library. If not, see <http://www.gnu.org/licenses/>.
+
+package keystore
+
+import (
+	"crypto/rand"
+	"encoding/hex"
+	"fmt"
+	"io/ioutil"
+	"os"
+	"path/filepath"
+	"reflect"
+	"strings"
+	"testing"
+
+	"github.com/ethereum/go-ethereum/common"
+	"github.com/ethereum/go-ethereum/crypto"
+)
+
+func tmpKeyStoreIface(t *testing.T, encrypted bool) (dir string, ks keyStore) {
+	d, err := ioutil.TempDir("", "geth-keystore-test")
+	if err != nil {
+		t.Fatal(err)
+	}
+	if encrypted {
+		ks = &keyStorePassphrase{d, veryLightScryptN, veryLightScryptP, true}
+	} else {
+		ks = &keyStorePlain{d}
+	}
+	return d, ks
+}
+
+func TestKeyStorePlain(t *testing.T) {
+	dir, ks := tmpKeyStoreIface(t, false)
+	defer os.RemoveAll(dir)
+
+	pass := "" // not used but required by API
+	k1, account, err := storeNewKey(ks, rand.Reader, pass)
+	if err != nil {
+		t.Fatal(err)
+	}
+	k2, err := ks.GetKey(k1.Address, account.URL.Path, pass)
+	if err != nil {
+		t.Fatal(err)
+	}
+	if !reflect.DeepEqual(k1.Address, k2.Address) {
+		t.Fatal(err)
+	}
+	if !reflect.DeepEqual(k1.PrivateKey, k2.PrivateKey) {
+		t.Fatal(err)
+	}
+}
+
+func TestKeyStorePassphrase(t *testing.T) {
+	dir, ks := tmpKeyStoreIface(t, true)
+	defer os.RemoveAll(dir)
+
+	pass := "foo"
+	k1, account, err := storeNewKey(ks, rand.Reader, pass)
+	if err != nil {
+		t.Fatal(err)
+	}
+	k2, err := ks.GetKey(k1.Address, account.URL.Path, pass)
+	if err != nil {
+		t.Fatal(err)
+	}
+	if !reflect.DeepEqual(k1.Address, k2.Address) {
+		t.Fatal(err)
+	}
+	if !reflect.DeepEqual(k1.PrivateKey, k2.PrivateKey) {
+		t.Fatal(err)
+	}
+}
+
+func TestKeyStorePassphraseDecryptionFail(t *testing.T) {
+	dir, ks := tmpKeyStoreIface(t, true)
+	defer os.RemoveAll(dir)
+
+	pass := "foo"
+	k1, account, err := storeNewKey(ks, rand.Reader, pass)
+	if err != nil {
+		t.Fatal(err)
+	}
+	if _, err = ks.GetKey(k1.Address, account.URL.Path, "bar"); err != ErrDecrypt {
+		t.Fatalf("wrong error for invalid passphrase\ngot %q\nwant %q", err, ErrDecrypt)
+	}
+}
+
+func TestImportPreSaleKey(t *testing.T) {
+	dir, ks := tmpKeyStoreIface(t, true)
+	defer os.RemoveAll(dir)
+
+	// file content of a presale key file generated with:
+	// python pyethsaletool.py genwallet
+	// with password "foo"
+	fileContent := "{\"encseed\": \"26d87f5f2bf9835f9a47eefae571bc09f9107bb13d54ff12a4ec095d01f83897494cf34f7bed2ed34126ecba9db7b62de56c9d7cd136520a0427bfb11b8954ba7ac39b90d4650d3448e31185affcd74226a68f1e94b1108e6e0a4a91cdd83eba\", \"ethaddr\": \"d4584b5f6229b7be90727b0fc8c6b91bb427821f\", \"email\": \"gustav.simonsson@gmail.com\", \"btcaddr\": \"1EVknXyFC68kKNLkh6YnKzW41svSRoaAcx\"}"
+	pass := "foo"
+	account, _, err := importPreSaleKey(ks, []byte(fileContent), pass)
+	if err != nil {
+		t.Fatal(err)
+	}
+	if account.Address != common.HexToAddress("d4584b5f6229b7be90727b0fc8c6b91bb427821f") {
+		t.Errorf("imported account has wrong address %x", account.Address)
+	}
+	if !strings.HasPrefix(account.URL.Path, dir) {
+		t.Errorf("imported account file not in keystore directory: %q", account.URL)
+	}
+}
+
+// Test and utils for the key store tests in the Ethereum JSON tests;
+// testdataKeyStoreTests/basic_tests.json
+type KeyStoreTestV3 struct {
+	Json     encryptedKeyJSONV3
+	Password string
+	Priv     string
+}
+
+type KeyStoreTestV1 struct {
+	Json     encryptedKeyJSONV1
+	Password string
+	Priv     string
+}
+
+func TestV3_PBKDF2_1(t *testing.T) {
+	t.Parallel()
+	tests := loadKeyStoreTestV3("testdata/v3_test_vector.json", t)
+	testDecryptV3(tests["wikipage_test_vector_pbkdf2"], t)
+}
+
+var testsSubmodule = filepath.Join("..", "..", "tests", "testdata", "KeyStoreTests")
+
+func skipIfSubmoduleMissing(t *testing.T) {
+	if !common.FileExist(testsSubmodule) {
+		t.Skipf("can't find JSON tests from submodule at %s", testsSubmodule)
+	}
+}
+
+func TestV3_PBKDF2_2(t *testing.T) {
+	skipIfSubmoduleMissing(t)
+	t.Parallel()
+	tests := loadKeyStoreTestV3(filepath.Join(testsSubmodule, "basic_tests.json"), t)
+	testDecryptV3(tests["test1"], t)
+}
+
+func TestV3_PBKDF2_3(t *testing.T) {
+	skipIfSubmoduleMissing(t)
+	t.Parallel()
+	tests := loadKeyStoreTestV3(filepath.Join(testsSubmodule, "basic_tests.json"), t)
+	testDecryptV3(tests["python_generated_test_with_odd_iv"], t)
+}
+
+func TestV3_PBKDF2_4(t *testing.T) {
+	skipIfSubmoduleMissing(t)
+	t.Parallel()
+	tests := loadKeyStoreTestV3(filepath.Join(testsSubmodule, "basic_tests.json"), t)
+	testDecryptV3(tests["evilnonce"], t)
+}
+
+func TestV3_Scrypt_1(t *testing.T) {
+	t.Parallel()
+	tests := loadKeyStoreTestV3("testdata/v3_test_vector.json", t)
+	testDecryptV3(tests["wikipage_test_vector_scrypt"], t)
+}
+
+func TestV3_Scrypt_2(t *testing.T) {
+	skipIfSubmoduleMissing(t)
+	t.Parallel()
+	tests := loadKeyStoreTestV3(filepath.Join(testsSubmodule, "basic_tests.json"), t)
+	testDecryptV3(tests["test2"], t)
+}
+
+func TestV1_1(t *testing.T) {
+	t.Parallel()
+	tests := loadKeyStoreTestV1("testdata/v1_test_vector.json", t)
+	testDecryptV1(tests["test1"], t)
+}
+
+func TestV1_2(t *testing.T) {
+	t.Parallel()
+	ks := &keyStorePassphrase{"testdata/v1", LightScryptN, LightScryptP, true}
+	addr := common.HexToAddress("cb61d5a9c4896fb9658090b597ef0e7be6f7b67e")
+	file := "testdata/v1/cb61d5a9c4896fb9658090b597ef0e7be6f7b67e/cb61d5a9c4896fb9658090b597ef0e7be6f7b67e"
+	k, err := ks.GetKey(addr, file, "g")
+	if err != nil {
+		t.Fatal(err)
+	}
+	privHex := hex.EncodeToString(crypto.FromECDSA(k.PrivateKey))
+	expectedHex := "d1b1178d3529626a1a93e073f65028370d14c7eb0936eb42abef05db6f37ad7d"
+	if privHex != expectedHex {
+		t.Fatal(fmt.Errorf("Unexpected privkey: %v, expected %v", privHex, expectedHex))
+	}
+}
+
+func testDecryptV3(test KeyStoreTestV3, t *testing.T) {
+	privBytes, _, err := decryptKeyV3(&test.Json, test.Password)
+	if err != nil {
+		t.Fatal(err)
+	}
+	privHex := hex.EncodeToString(privBytes)
+	if test.Priv != privHex {
+		t.Fatal(fmt.Errorf("Decrypted bytes not equal to test, expected %v have %v", test.Priv, privHex))
+	}
+}
+
+func testDecryptV1(test KeyStoreTestV1, t *testing.T) {
+	privBytes, _, err := decryptKeyV1(&test.Json, test.Password)
+	if err != nil {
+		t.Fatal(err)
+	}
+	privHex := hex.EncodeToString(privBytes)
+	if test.Priv != privHex {
+		t.Fatal(fmt.Errorf("Decrypted bytes not equal to test, expected %v have %v", test.Priv, privHex))
+	}
+}
+
+func loadKeyStoreTestV3(file string, t *testing.T) map[string]KeyStoreTestV3 {
+	tests := make(map[string]KeyStoreTestV3)
+	err := common.LoadJSON(file, &tests)
+	if err != nil {
+		t.Fatal(err)
+	}
+	return tests
+}
+
+func loadKeyStoreTestV1(file string, t *testing.T) map[string]KeyStoreTestV1 {
+	tests := make(map[string]KeyStoreTestV1)
+	err := common.LoadJSON(file, &tests)
+	if err != nil {
+		t.Fatal(err)
+	}
+	return tests
+}
+
+func TestKeyForDirectICAP(t *testing.T) {
+	t.Parallel()
+	key := NewKeyForDirectICAP(rand.Reader)
+	if !strings.HasPrefix(key.Address.Hex(), "0x00") {
+		t.Errorf("Expected first address byte to be zero, have: %s", key.Address.Hex())
+	}
+}
+
+func TestV3_31_Byte_Key(t *testing.T) {
+	t.Parallel()
+	tests := loadKeyStoreTestV3("testdata/v3_test_vector.json", t)
+	testDecryptV3(tests["31_byte_key"], t)
+}
+
+func TestV3_30_Byte_Key(t *testing.T) {
+	t.Parallel()
+	tests := loadKeyStoreTestV3("testdata/v3_test_vector.json", t)
+	testDecryptV3(tests["30_byte_key"], t)
+}

accounts/keystore/presale.go

@@ -0,0 +1,147 @@
+// Copyright 2016 The go-ethereum Authors
+// This file is part of the go-ethereum library.
+//
+// The go-ethereum library is free software: you can redistribute it and/or modify
+// it under the terms of the GNU Lesser General Public License as published by
+// the Free Software Foundation, either version 3 of the License, or
+// (at your option) any later version.
+//
+// The go-ethereum library is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+// GNU Lesser General Public License for more details.
+//
+// You should have received a copy of the GNU Lesser General Public License
+// along with the go-ethereum library. If not, see <http://www.gnu.org/licenses/>.
+
+package keystore
+
+import (
+	"crypto/aes"
+	"crypto/cipher"
+	"crypto/sha256"
+	"encoding/hex"
+	"encoding/json"
+	"errors"
+	"fmt"
+
+	"github.com/ethereum/go-ethereum/accounts"
+	"github.com/ethereum/go-ethereum/crypto"
+	"github.com/pborman/uuid"
+	"golang.org/x/crypto/pbkdf2"
+)
+
+// creates a Key and stores that in the given KeyStore by decrypting a presale key JSON
+func importPreSaleKey(keyStore keyStore, keyJSON []byte, password string) (accounts.Account, *Key, error) {
+	key, err := decryptPreSaleKey(keyJSON, password)
+	if err != nil {
+		return accounts.Account{}, nil, err
+	}
+	key.Id = uuid.NewRandom()
+	a := accounts.Account{
+		Address: key.Address,
+		URL: accounts.URL{
+			Scheme: KeyStoreScheme,
+			Path:   keyStore.JoinPath(keyFileName(key.Address)),
+		},
+	}
+	err = keyStore.StoreKey(a.URL.Path, key, password)
+	return a, key, err
+}
+
+func decryptPreSaleKey(fileContent []byte, password string) (key *Key, err error) {
+	preSaleKeyStruct := struct {
+		EncSeed string
+		EthAddr string
+		Email   string
+		BtcAddr string
+	}{}
+	err = json.Unmarshal(fileContent, &preSaleKeyStruct)
+	if err != nil {
+		return nil, err
+	}
+	encSeedBytes, err := hex.DecodeString(preSaleKeyStruct.EncSeed)
+	if err != nil {
+		return nil, errors.New("invalid hex in encSeed")
+	}
+	if len(encSeedBytes) < 16 {
+		return nil, errors.New("invalid encSeed, too short")
+	}
+	iv := encSeedBytes[:16]
+	cipherText := encSeedBytes[16:]
+	/*
+		See https://github.com/ethereum/pyethsaletool
+
+		pyethsaletool generates the encryption key from password by
+		2000 rounds of PBKDF2 with HMAC-SHA-256 using password as salt (:().
+		16 byte key length within PBKDF2 and resulting key is used as AES key
+	*/
+	passBytes := []byte(password)
+	derivedKey := pbkdf2.Key(passBytes, passBytes, 2000, 16, sha256.New)
+	plainText, err := aesCBCDecrypt(derivedKey, cipherText, iv)
+	if err != nil {
+		return nil, err
+	}
+	ethPriv := crypto.Keccak256(plainText)
+	ecKey := crypto.ToECDSAUnsafe(ethPriv)
+
+	key = &Key{
+		Id:         nil,
+		Address:    crypto.PubkeyToAddress(ecKey.PublicKey),
+		PrivateKey: ecKey,
+	}
+	derivedAddr := hex.EncodeToString(key.Address.Bytes()) // needed because .Hex() gives leading "0x"
+	expectedAddr := preSaleKeyStruct.EthAddr
+	if derivedAddr != expectedAddr {
+		err = fmt.Errorf("decrypted addr '%s' not equal to expected addr '%s'", derivedAddr, expectedAddr)
+	}
+	return key, err
+}
+
+func aesCTRXOR(key, inText, iv []byte) ([]byte, error) {
+	// AES-128 is selected due to size of encryptKey.
+	aesBlock, err := aes.NewCipher(key)
+	if err != nil {
+		return nil, err
+	}
+	stream := cipher.NewCTR(aesBlock, iv)
+	outText := make([]byte, len(inText))
+	stream.XORKeyStream(outText, inText)
+	return outText, err
+}
+
+func aesCBCDecrypt(key, cipherText, iv []byte) ([]byte, error) {
+	aesBlock, err := aes.NewCipher(key)
+	if err != nil {
+		return nil, err
+	}
+	decrypter := cipher.NewCBCDecrypter(aesBlock, iv)
+	paddedPlaintext := make([]byte, len(cipherText))
+	decrypter.CryptBlocks(paddedPlaintext, cipherText)
+	plaintext := pkcs7Unpad(paddedPlaintext)
+	if plaintext == nil {
+		return nil, ErrDecrypt
+	}
+	return plaintext, err
+}
+
+// From https://leanpub.com/gocrypto/read#leanpub-auto-block-cipher-modes
+func pkcs7Unpad(in []byte) []byte {
+	if len(in) == 0 {
+		return nil
+	}
+
+	padding := in[len(in)-1]
+	if int(padding) > len(in) || padding > aes.BlockSize {
+		return nil
+	} else if padding == 0 {
+		return nil
+	}
+
+	for i := len(in) - 1; i > len(in)-int(padding)-1; i-- {
+		if in[i] != padding {
+			return nil
+		}
+	}
+	return in[:len(in)-int(padding)]
+}

accounts/keystore/testdata/dupes/1

@@ -0,0 +1 @@
+{"address":"f466859ead1932d743d622cb74fc058882e8648a","crypto":{"cipher":"aes-128-ctr","ciphertext":"cb664472deacb41a2e995fa7f96fe29ce744471deb8d146a0e43c7898c9ddd4d","cipherparams":{"iv":"dfd9ee70812add5f4b8f89d0811c9158"},"kdf":"scrypt","kdfparams":{"dklen":32,"n":8,"p":16,"r":8,"salt":"0d6769bf016d45c479213990d6a08d938469c4adad8a02ce507b4a4e7b7739f1"},"mac":"bac9af994b15a45dd39669fc66f9aa8a3b9dd8c22cb16e4d8d7ea089d0f1a1a9"},"id":"472e8b3d-afb6-45b5-8111-72c89895099a","version":3}

accounts/keystore/testdata/dupes/2

@@ -0,0 +1 @@
+{"address":"f466859ead1932d743d622cb74fc058882e8648a","crypto":{"cipher":"aes-128-ctr","ciphertext":"cb664472deacb41a2e995fa7f96fe29ce744471deb8d146a0e43c7898c9ddd4d","cipherparams":{"iv":"dfd9ee70812add5f4b8f89d0811c9158"},"kdf":"scrypt","kdfparams":{"dklen":32,"n":8,"p":16,"r":8,"salt":"0d6769bf016d45c479213990d6a08d938469c4adad8a02ce507b4a4e7b7739f1"},"mac":"bac9af994b15a45dd39669fc66f9aa8a3b9dd8c22cb16e4d8d7ea089d0f1a1a9"},"id":"472e8b3d-afb6-45b5-8111-72c89895099a","version":3}

accounts/keystore/testdata/dupes/foo

@@ -0,0 +1 @@
+{"address":"7ef5a6135f1fd6a02593eedc869c6d41d934aef8","crypto":{"cipher":"aes-128-ctr","ciphertext":"1d0839166e7a15b9c1333fc865d69858b22df26815ccf601b28219b6192974e1","cipherparams":{"iv":"8df6caa7ff1b00c4e871f002cb7921ed"},"kdf":"scrypt","kdfparams":{"dklen":32,"n":8,"p":16,"r":8,"salt":"e5e6ef3f4ea695f496b643ebd3f75c0aa58ef4070e90c80c5d3fb0241bf1595c"},"mac":"6d16dfde774845e4585357f24bce530528bc69f4f84e1e22880d34fa45c273e5"},"id":"950077c7-71e3-4c44-a4a1-143919141ed4","version":3}

accounts/keystore/testdata/keystore/.hiddenfile

@@ -0,0 +1 @@
+{"address":"f466859ead1932d743d622cb74fc058882e8648a","crypto":{"cipher":"aes-128-ctr","ciphertext":"cb664472deacb41a2e995fa7f96fe29ce744471deb8d146a0e43c7898c9ddd4d","cipherparams":{"iv":"dfd9ee70812add5f4b8f89d0811c9158"},"kdf":"scrypt","kdfparams":{"dklen":32,"n":8,"p":16,"r":8,"salt":"0d6769bf016d45c479213990d6a08d938469c4adad8a02ce507b4a4e7b7739f1"},"mac":"bac9af994b15a45dd39669fc66f9aa8a3b9dd8c22cb16e4d8d7ea089d0f1a1a9"},"id":"472e8b3d-afb6-45b5-8111-72c89895099a","version":3}

accounts/keystore/testdata/keystore/README

@@ -0,0 +1,21 @@
+This directory contains accounts for testing.
+The passphrase that unlocks them is "foobar".
+
+The "good" key files which are supposed to be loadable are:
+
+- File: UTC--2016-03-22T12-57-55.920751759Z--7ef5a6135f1fd6a02593eedc869c6d41d934aef8
+  Address: 0x7ef5a6135f1fd6a02593eedc869c6d41d934aef8
+- File: aaa
+  Address: 0xf466859ead1932d743d622cb74fc058882e8648a
+- File: zzz
+  Address: 0x289d485d9771714cce91d3393d764e1311907acc
+
+The other files (including this README) are broken in various ways
+and should not be picked up by package accounts:
+
+- File: no-address (missing address field, otherwise same as "aaa")
+- File: garbage (file with random data)
+- File: empty (file with no content)
+- File: swapfile~ (should be skipped)
+- File: .hiddenfile (should be skipped)
+- File: foo/... (should be skipped because it is a directory)

accounts/keystore/testdata/keystore/UTC--2016-03-22T12-57-55.920751759Z--7ef5a6135f1fd6a02593eedc869c6d41d934aef8

@@ -0,0 +1 @@
+{"address":"7ef5a6135f1fd6a02593eedc869c6d41d934aef8","crypto":{"cipher":"aes-128-ctr","ciphertext":"1d0839166e7a15b9c1333fc865d69858b22df26815ccf601b28219b6192974e1","cipherparams":{"iv":"8df6caa7ff1b00c4e871f002cb7921ed"},"kdf":"scrypt","kdfparams":{"dklen":32,"n":8,"p":16,"r":8,"salt":"e5e6ef3f4ea695f496b643ebd3f75c0aa58ef4070e90c80c5d3fb0241bf1595c"},"mac":"6d16dfde774845e4585357f24bce530528bc69f4f84e1e22880d34fa45c273e5"},"id":"950077c7-71e3-4c44-a4a1-143919141ed4","version":3}

accounts/keystore/testdata/keystore/aaa

@@ -0,0 +1 @@
+{"address":"f466859ead1932d743d622cb74fc058882e8648a","crypto":{"cipher":"aes-128-ctr","ciphertext":"cb664472deacb41a2e995fa7f96fe29ce744471deb8d146a0e43c7898c9ddd4d","cipherparams":{"iv":"dfd9ee70812add5f4b8f89d0811c9158"},"kdf":"scrypt","kdfparams":{"dklen":32,"n":8,"p":16,"r":8,"salt":"0d6769bf016d45c479213990d6a08d938469c4adad8a02ce507b4a4e7b7739f1"},"mac":"bac9af994b15a45dd39669fc66f9aa8a3b9dd8c22cb16e4d8d7ea089d0f1a1a9"},"id":"472e8b3d-afb6-45b5-8111-72c89895099a","version":3}

accounts/keystore/testdata/keystore/foo/fd9bd350f08ee3c0c19b85a8e16114a11a60aa4e

@@ -0,0 +1 @@
+{"address":"fd9bd350f08ee3c0c19b85a8e16114a11a60aa4e","crypto":{"cipher":"aes-128-ctr","ciphertext":"8124d5134aa4a927c79fd852989e4b5419397566f04b0936a1eb1d168c7c68a5","cipherparams":{"iv":"e2febe17176414dd2cda28287947eb2f"},"kdf":"scrypt","kdfparams":{"dklen":32,"n":4096,"p":6,"r":8,"salt":"44b415ede89f3bdd6830390a21b78965f571b347a589d1d943029f016c5e8bd5"},"mac":"5e149ff25bfd9dd45746a84bb2bcd2f015f2cbca2b6d25c5de8c29617f71fe5b"},"id":"d6ac5452-2b2c-4d3c-ad80-4bf0327d971c","version":3}

accounts/keystore/testdata/keystore/no-address

@@ -0,0 +1 @@
+{"crypto":{"cipher":"aes-128-ctr","ciphertext":"cb664472deacb41a2e995fa7f96fe29ce744471deb8d146a0e43c7898c9ddd4d","cipherparams":{"iv":"dfd9ee70812add5f4b8f89d0811c9158"},"kdf":"scrypt","kdfparams":{"dklen":32,"n":8,"p":16,"r":8,"salt":"0d6769bf016d45c479213990d6a08d938469c4adad8a02ce507b4a4e7b7739f1"},"mac":"bac9af994b15a45dd39669fc66f9aa8a3b9dd8c22cb16e4d8d7ea089d0f1a1a9"},"id":"472e8b3d-afb6-45b5-8111-72c89895099a","version":3}

accounts/keystore/testdata/keystore/zero

@@ -0,0 +1 @@
+{"address":"0000000000000000000000000000000000000000","crypto":{"cipher":"aes-128-ctr","ciphertext":"cb664472deacb41a2e995fa7f96fe29ce744471deb8d146a0e43c7898c9ddd4d","cipherparams":{"iv":"dfd9ee70812add5f4b8f89d0811c9158"},"kdf":"scrypt","kdfparams":{"dklen":32,"n":8,"p":16,"r":8,"salt":"0d6769bf016d45c479213990d6a08d938469c4adad8a02ce507b4a4e7b7739f1"},"mac":"bac9af994b15a45dd39669fc66f9aa8a3b9dd8c22cb16e4d8d7ea089d0f1a1a9"},"id":"472e8b3d-afb6-45b5-8111-72c89895099a","version":3}

accounts/keystore/testdata/keystore/zzz

@@ -0,0 +1 @@
+{"address":"289d485d9771714cce91d3393d764e1311907acc","crypto":{"cipher":"aes-128-ctr","ciphertext":"faf32ca89d286b107f5e6d842802e05263c49b78d46eac74e6109e9a963378ab","cipherparams":{"iv":"558833eec4a665a8c55608d7d503407d"},"kdf":"scrypt","kdfparams":{"dklen":32,"n":8,"p":16,"r":8,"salt":"d571fff447ffb24314f9513f5160246f09997b857ac71348b73e785aab40dc04"},"mac":"21edb85ff7d0dab1767b9bf498f2c3cb7be7609490756bd32300bb213b59effe"},"id":"3279afcf-55ba-43ff-8997-02dcc46a6525","version":3}

accounts/keystore/testdata/v1/cb61d5a9c4896fb9658090b597ef0e7be6f7b67e/cb61d5a9c4896fb9658090b597ef0e7be6f7b67e

@@ -0,0 +1 @@
+{"address":"cb61d5a9c4896fb9658090b597ef0e7be6f7b67e","Crypto":{"cipher":"aes-128-cbc","ciphertext":"6143d3192db8b66eabd693d9c4e414dcfaee52abda451af79ccf474dafb35f1bfc7ea013aa9d2ee35969a1a2e8d752d0","cipherparams":{"iv":"35337770fc2117994ecdcad026bccff4"},"kdf":"scrypt","kdfparams":{"n":262144,"r":8,"p":1,"dklen":32,"salt":"9afcddebca541253a2f4053391c673ff9fe23097cd8555d149d929e4ccf1257f"},"mac":"3f3d5af884b17a100b0b3232c0636c230a54dc2ac8d986227219b0dd89197644","version":"1"},"id":"e25f7c1f-d318-4f29-b62c-687190d4d299","version":"1"}

accounts/keystore/testdata/v1_test_vector.json

@@ -0,0 +1,28 @@
+{
+    "test1": {
+        "json": {
+            "Crypto": {
+                "cipher": "aes-128-cbc",
+                "cipherparams": {
+                    "iv": "35337770fc2117994ecdcad026bccff4"
+                },
+                "ciphertext": "6143d3192db8b66eabd693d9c4e414dcfaee52abda451af79ccf474dafb35f1bfc7ea013aa9d2ee35969a1a2e8d752d0",
+                "kdf": "scrypt",
+                "kdfparams": {
+                    "dklen": 32,
+                    "n": 262144,
+                    "p": 1,
+                    "r": 8,
+                    "salt": "9afcddebca541253a2f4053391c673ff9fe23097cd8555d149d929e4ccf1257f"
+                },
+                "mac": "3f3d5af884b17a100b0b3232c0636c230a54dc2ac8d986227219b0dd89197644",
+                "version": "1"
+            },
+            "address": "cb61d5a9c4896fb9658090b597ef0e7be6f7b67e",
+            "id": "e25f7c1f-d318-4f29-b62c-687190d4d299",
+            "version": "1"
+        },
+        "password": "g",
+        "priv": "d1b1178d3529626a1a93e073f65028370d14c7eb0936eb42abef05db6f37ad7d"
+    }
+}

accounts/keystore/testdata/v3_test_vector.json

@@ -0,0 +1,97 @@
+{
+    "wikipage_test_vector_scrypt": {
+        "json": {
+            "crypto" : {
+                "cipher" : "aes-128-ctr",
+                "cipherparams" : {
+                    "iv" : "83dbcc02d8ccb40e466191a123791e0e"
+                },
+                "ciphertext" : "d172bf743a674da9cdad04534d56926ef8358534d458fffccd4e6ad2fbde479c",
+                "kdf" : "scrypt",
+                "kdfparams" : {
+                    "dklen" : 32,
+                    "n" : 262144,
+                    "r" : 1,
+                    "p" : 8,
+                    "salt" : "ab0c7876052600dd703518d6fc3fe8984592145b591fc8fb5c6d43190334ba19"
+                },
+                "mac" : "2103ac29920d71da29f15d75b4a16dbe95cfd7ff8faea1056c33131d846e3097"
+            },
+            "id" : "3198bc9c-6672-5ab3-d995-4942343ae5b6",
+            "version" : 3
+        },
+        "password": "testpassword",
+        "priv": "7a28b5ba57c53603b0b07b56bba752f7784bf506fa95edc395f5cf6c7514fe9d"
+    },
+    "wikipage_test_vector_pbkdf2": {
+        "json": {
+            "crypto" : {
+                "cipher" : "aes-128-ctr",
+                "cipherparams" : {
+                    "iv" : "6087dab2f9fdbbfaddc31a909735c1e6"
+                },
+                "ciphertext" : "5318b4d5bcd28de64ee5559e671353e16f075ecae9f99c7a79a38af5f869aa46",
+                "kdf" : "pbkdf2",
+                "kdfparams" : {
+                    "c" : 262144,
+                    "dklen" : 32,
+                    "prf" : "hmac-sha256",
+                    "salt" : "ae3cd4e7013836a3df6bd7241b12db061dbe2c6785853cce422d148a624ce0bd"
+                },
+                "mac" : "517ead924a9d0dc3124507e3393d175ce3ff7c1e96529c6c555ce9e51205e9b2"
+            },
+            "id" : "3198bc9c-6672-5ab3-d995-4942343ae5b6",
+            "version" : 3
+        },
+        "password": "testpassword",
+        "priv": "7a28b5ba57c53603b0b07b56bba752f7784bf506fa95edc395f5cf6c7514fe9d"
+    },
+    "31_byte_key": {
+        "json": {
+            "crypto" : {
+                "cipher" : "aes-128-ctr",
+                "cipherparams" : {
+                    "iv" : "e0c41130a323adc1446fc82f724bca2f"
+                },
+                "ciphertext" : "9517cd5bdbe69076f9bf5057248c6c050141e970efa36ce53692d5d59a3984",
+                "kdf" : "scrypt",
+                "kdfparams" : {
+                    "dklen" : 32,
+                    "n" : 2,
+                    "r" : 8,
+                    "p" : 1,
+                    "salt" : "711f816911c92d649fb4c84b047915679933555030b3552c1212609b38208c63"
+                },
+                "mac" : "d5e116151c6aa71470e67a7d42c9620c75c4d23229847dcc127794f0732b0db5"
+            },
+            "id" : "fecfc4ce-e956-48fd-953b-30f8b52ed66c",
+            "version" : 3
+        },
+        "password": "foo",
+        "priv": "fa7b3db73dc7dfdf8c5fbdb796d741e4488628c41fc4febd9160a866ba0f35"
+    },
+    "30_byte_key": {
+        "json": {
+            "crypto" : {
+                "cipher" : "aes-128-ctr",
+                "cipherparams" : {
+                    "iv" : "3ca92af36ad7c2cd92454c59cea5ef00"
+                },
+                "ciphertext" : "108b7d34f3442fc26ab1ab90ca91476ba6bfa8c00975a49ef9051dc675aa",
+                "kdf" : "scrypt",
+                "kdfparams" : {
+                    "dklen" : 32,
+                    "n" : 2,
+                    "r" : 8,
+                    "p" : 1,
+                    "salt" : "d0769e608fb86cda848065642a9c6fa046845c928175662b8e356c77f914cd3b"
+                },
+                "mac" : "75d0e6759f7b3cefa319c3be41680ab6beea7d8328653474bd06706d4cc67420"
+            },
+            "id" : "a37e1559-5955-450d-8075-7b8931b392b2",
+            "version" : 3
+        },
+        "password": "foo",
+        "priv": "81c29e8142bb6a81bef5a92bda7a8328a5c85bb2f9542e76f9b0f94fc018"
+    }
+}

accounts/keystore/testdata/very-light-scrypt.json

@@ -0,0 +1 @@
+{"address":"45dea0fb0bba44f4fcf290bba71fd57d7117cbb8","crypto":{"cipher":"aes-128-ctr","ciphertext":"b87781948a1befd247bff51ef4063f716cf6c2d3481163e9a8f42e1f9bb74145","cipherparams":{"iv":"dc4926b48a105133d2f16b96833abf1e"},"kdf":"scrypt","kdfparams":{"dklen":32,"n":2,"p":1,"r":8,"salt":"004244bbdc51cadda545b1cfa43cff9ed2ae88e08c61f1479dbb45410722f8f0"},"mac":"39990c1684557447940d4c69e06b1b82b2aceacb43f284df65c956daf3046b85"},"id":"ce541d8d-c79b-40f8-9f8c-20f59616faba","version":3}

accounts/keystore/wallet.go

@@ -0,0 +1,148 @@
+// Copyright 2017 The go-ethereum Authors
+// This file is part of the go-ethereum library.
+//
+// The go-ethereum library is free software: you can redistribute it and/or modify
+// it under the terms of the GNU Lesser General Public License as published by
+// the Free Software Foundation, either version 3 of the License, or
+// (at your option) any later version.
+//
+// The go-ethereum library is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+// GNU Lesser General Public License for more details.
+//
+// You should have received a copy of the GNU Lesser General Public License
+// along with the go-ethereum library. If not, see <http://www.gnu.org/licenses/>.
+
+package keystore
+
+import (
+	"math/big"
+
+	ethereum "github.com/ethereum/go-ethereum"
+	"github.com/ethereum/go-ethereum/accounts"
+	"github.com/ethereum/go-ethereum/core/types"
+	"github.com/ethereum/go-ethereum/crypto"
+)
+
+// keystoreWallet implements the accounts.Wallet interface for the original
+// keystore.
+type keystoreWallet struct {
+	account  accounts.Account // Single account contained in this wallet
+	keystore *KeyStore        // Keystore where the account originates from
+}
+
+// URL implements accounts.Wallet, returning the URL of the account within.
+func (w *keystoreWallet) URL() accounts.URL {
+	return w.account.URL
+}
+
+// Status implements accounts.Wallet, returning whether the account held by the
+// keystore wallet is unlocked or not.
+func (w *keystoreWallet) Status() (string, error) {
+	w.keystore.mu.RLock()
+	defer w.keystore.mu.RUnlock()
+
+	if _, ok := w.keystore.unlocked[w.account.Address]; ok {
+		return "Unlocked", nil
+	}
+	return "Locked", nil
+}
+
+// Open implements accounts.Wallet, but is a noop for plain wallets since there
+// is no connection or decryption step necessary to access the list of accounts.
+func (w *keystoreWallet) Open(passphrase string) error { return nil }
+
+// Close implements accounts.Wallet, but is a noop for plain wallets since there
+// is no meaningful open operation.
+func (w *keystoreWallet) Close() error { return nil }
+
+// Accounts implements accounts.Wallet, returning an account list consisting of
+// a single account that the plain kestore wallet contains.
+func (w *keystoreWallet) Accounts() []accounts.Account {
+	return []accounts.Account{w.account}
+}
+
+// Contains implements accounts.Wallet, returning whether a particular account is
+// or is not wrapped by this wallet instance.
+func (w *keystoreWallet) Contains(account accounts.Account) bool {
+	return account.Address == w.account.Address && (account.URL == (accounts.URL{}) || account.URL == w.account.URL)
+}
+
+// Derive implements accounts.Wallet, but is a noop for plain wallets since there
+// is no notion of hierarchical account derivation for plain keystore accounts.
+func (w *keystoreWallet) Derive(path accounts.DerivationPath, pin bool) (accounts.Account, error) {
+	return accounts.Account{}, accounts.ErrNotSupported
+}
+
+// SelfDerive implements accounts.Wallet, but is a noop for plain wallets since
+// there is no notion of hierarchical account derivation for plain keystore accounts.
+func (w *keystoreWallet) SelfDerive(bases []accounts.DerivationPath, chain ethereum.ChainStateReader) {
+}
+
+// signHash attempts to sign the given hash with
+// the given account. If the wallet does not wrap this particular account, an
+// error is returned to avoid account leakage (even though in theory we may be
+// able to sign via our shared keystore backend).
+func (w *keystoreWallet) signHash(account accounts.Account, hash []byte) ([]byte, error) {
+	// Make sure the requested account is contained within
+	if !w.Contains(account) {
+		return nil, accounts.ErrUnknownAccount
+	}
+	// Account seems valid, request the keystore to sign
+	return w.keystore.SignHash(account, hash)
+}
+
+// SignData signs keccak256(data). The mimetype parameter describes the type of data being signed
+func (w *keystoreWallet) SignData(account accounts.Account, mimeType string, data []byte) ([]byte, error) {
+	return w.signHash(account, crypto.Keccak256(data))
+}
+
+// SignDataWithPassphrase signs keccak256(data). The mimetype parameter describes the type of data being signed
+func (w *keystoreWallet) SignDataWithPassphrase(account accounts.Account, passphrase, mimeType string, data []byte) ([]byte, error) {
+	// Make sure the requested account is contained within
+	if !w.Contains(account) {
+		return nil, accounts.ErrUnknownAccount
+	}
+	// Account seems valid, request the keystore to sign
+	return w.keystore.SignHashWithPassphrase(account, passphrase, crypto.Keccak256(data))
+}
+
+func (w *keystoreWallet) SignText(account accounts.Account, text []byte) ([]byte, error) {
+	return w.signHash(account, accounts.TextHash(text))
+}
+
+// SignTextWithPassphrase implements accounts.Wallet, attempting to sign the
+// given hash with the given account using passphrase as extra authentication.
+func (w *keystoreWallet) SignTextWithPassphrase(account accounts.Account, passphrase string, text []byte) ([]byte, error) {
+	// Make sure the requested account is contained within
+	if !w.Contains(account) {
+		return nil, accounts.ErrUnknownAccount
+	}
+	// Account seems valid, request the keystore to sign
+	return w.keystore.SignHashWithPassphrase(account, passphrase, accounts.TextHash(text))
+}
+
+// SignTx implements accounts.Wallet, attempting to sign the given transaction
+// with the given account. If the wallet does not wrap this particular account,
+// an error is returned to avoid account leakage (even though in theory we may
+// be able to sign via our shared keystore backend).
+func (w *keystoreWallet) SignTx(account accounts.Account, tx *types.Transaction, chainID *big.Int) (*types.Transaction, error) {
+	// Make sure the requested account is contained within
+	if !w.Contains(account) {
+		return nil, accounts.ErrUnknownAccount
+	}
+	// Account seems valid, request the keystore to sign
+	return w.keystore.SignTx(account, tx, chainID)
+}
+
+// SignTxWithPassphrase implements accounts.Wallet, attempting to sign the given
+// transaction with the given account using passphrase as extra authentication.
+func (w *keystoreWallet) SignTxWithPassphrase(account accounts.Account, passphrase string, tx *types.Transaction, chainID *big.Int) (*types.Transaction, error) {
+	// Make sure the requested account is contained within
+	if !w.Contains(account) {
+		return nil, accounts.ErrUnknownAccount
+	}
+	// Account seems valid, request the keystore to sign
+	return w.keystore.SignTxWithPassphrase(account, passphrase, tx, chainID)
+}

accounts/keystore/watch.go

@@ -0,0 +1,108 @@
+// Copyright 2016 The go-ethereum Authors
+// This file is part of the go-ethereum library.
+//
+// The go-ethereum library is free software: you can redistribute it and/or modify
+// it under the terms of the GNU Lesser General Public License as published by
+// the Free Software Foundation, either version 3 of the License, or
+// (at your option) any later version.
+//
+// The go-ethereum library is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+// GNU Lesser General Public License for more details.
+//
+// You should have received a copy of the GNU Lesser General Public License
+// along with the go-ethereum library. If not, see <http://www.gnu.org/licenses/>.
+
+// +build darwin,!ios freebsd linux,!arm64 netbsd solaris
+
+package keystore
+
+import (
+	"time"
+
+	"github.com/ethereum/go-ethereum/log"
+	"github.com/rjeczalik/notify"
+)
+
+type watcher struct {
+	ac       *accountCache
+	starting bool
+	running  bool
+	ev       chan notify.EventInfo
+	quit     chan struct{}
+}
+
+func newWatcher(ac *accountCache) *watcher {
+	return &watcher{
+		ac:   ac,
+		ev:   make(chan notify.EventInfo, 10),
+		quit: make(chan struct{}),
+	}
+}
+
+// starts the watcher loop in the background.
+// Start a watcher in the background if that's not already in progress.
+// The caller must hold w.ac.mu.
+func (w *watcher) start() {
+	if w.starting || w.running {
+		return
+	}
+	w.starting = true
+	go w.loop()
+}
+
+func (w *watcher) close() {
+	close(w.quit)
+}
+
+func (w *watcher) loop() {
+	defer func() {
+		w.ac.mu.Lock()
+		w.running = false
+		w.starting = false
+		w.ac.mu.Unlock()
+	}()
+	logger := log.New("path", w.ac.keydir)
+
+	if err := notify.Watch(w.ac.keydir, w.ev, notify.All); err != nil {
+		logger.Trace("Failed to watch keystore folder", "err", err)
+		return
+	}
+	defer notify.Stop(w.ev)
+	logger.Trace("Started watching keystore folder")
+	defer logger.Trace("Stopped watching keystore folder")
+
+	w.ac.mu.Lock()
+	w.running = true
+	w.ac.mu.Unlock()
+
+	// Wait for file system events and reload.
+	// When an event occurs, the reload call is delayed a bit so that
+	// multiple events arriving quickly only cause a single reload.
+	var (
+		debounceDuration = 500 * time.Millisecond
+		rescanTriggered  = false
+		debounce         = time.NewTimer(0)
+	)
+	// Ignore initial trigger
+	if !debounce.Stop() {
+		<-debounce.C
+	}
+	defer debounce.Stop()
+	for {
+		select {
+		case <-w.quit:
+			return
+		case <-w.ev:
+			// Trigger the scan (with delay), if not already triggered
+			if !rescanTriggered {
+				debounce.Reset(debounceDuration)
+				rescanTriggered = true
+			}
+		case <-debounce.C:
+			w.ac.scanAccounts()
+			rescanTriggered = false
+		}
+	}
+}

accounts/keystore/watch_fallback.go

@@ -0,0 +1,28 @@
+// Copyright 2016 The go-ethereum Authors
+// This file is part of the go-ethereum library.
+//
+// The go-ethereum library is free software: you can redistribute it and/or modify
+// it under the terms of the GNU Lesser General Public License as published by
+// the Free Software Foundation, either version 3 of the License, or
+// (at your option) any later version.
+//
+// The go-ethereum library is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+// GNU Lesser General Public License for more details.
+//
+// You should have received a copy of the GNU Lesser General Public License
+// along with the go-ethereum library. If not, see <http://www.gnu.org/licenses/>.
+
+// +build ios linux,arm64 windows !darwin,!freebsd,!linux,!netbsd,!solaris
+
+// This is the fallback implementation of directory watching.
+// It is used on unsupported platforms.
+
+package keystore
+
+type watcher struct{ running bool }
+
+func newWatcher(*accountCache) *watcher { return new(watcher) }
+func (*watcher) start()                 {}
+func (*watcher) close()                 {}

accounts/manager.go

@@ -0,0 +1,214 @@
+// Copyright 2017 The go-ethereum Authors
+// This file is part of the go-ethereum library.
+//
+// The go-ethereum library is free software: you can redistribute it and/or modify
+// it under the terms of the GNU Lesser General Public License as published by
+// the Free Software Foundation, either version 3 of the License, or
+// (at your option) any later version.
+//
+// The go-ethereum library is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+// GNU Lesser General Public License for more details.
+//
+// You should have received a copy of the GNU Lesser General Public License
+// along with the go-ethereum library. If not, see <http://www.gnu.org/licenses/>.
+
+package accounts
+
+import (
+	"reflect"
+	"sort"
+	"sync"
+
+	"github.com/ethereum/go-ethereum/event"
+)
+
+// Config contains the settings of the global account manager.
+//
+// TODO(rjl493456442, karalabe, holiman): Get rid of this when account management
+// is removed in favor of Clef.
+type Config struct {
+	InsecureUnlockAllowed bool // Whether account unlocking in insecure environment is allowed
+}
+
+// Manager is an overarching account manager that can communicate with various
+// backends for signing transactions.
+type Manager struct {
+	config   *Config                    // Global account manager configurations
+	backends map[reflect.Type][]Backend // Index of backends currently registered
+	updaters []event.Subscription       // Wallet update subscriptions for all backends
+	updates  chan WalletEvent           // Subscription sink for backend wallet changes
+	wallets  []Wallet                   // Cache of all wallets from all registered backends
+
+	feed event.Feed // Wallet feed notifying of arrivals/departures
+
+	quit chan chan error
+	lock sync.RWMutex
+}
+
+// NewManager creates a generic account manager to sign transaction via various
+// supported backends.
+func NewManager(config *Config, backends ...Backend) *Manager {
+	// Retrieve the initial list of wallets from the backends and sort by URL
+	var wallets []Wallet
+	for _, backend := range backends {
+		wallets = merge(wallets, backend.Wallets()...)
+	}
+	// Subscribe to wallet notifications from all backends
+	updates := make(chan WalletEvent, 4*len(backends))
+
+	subs := make([]event.Subscription, len(backends))
+	for i, backend := range backends {
+		subs[i] = backend.Subscribe(updates)
+	}
+	// Assemble the account manager and return
+	am := &Manager{
+		config:   config,
+		backends: make(map[reflect.Type][]Backend),
+		updaters: subs,
+		updates:  updates,
+		wallets:  wallets,
+		quit:     make(chan chan error),
+	}
+	for _, backend := range backends {
+		kind := reflect.TypeOf(backend)
+		am.backends[kind] = append(am.backends[kind], backend)
+	}
+	go am.update()
+
+	return am
+}
+
+// Close terminates the account manager's internal notification processes.
+func (am *Manager) Close() error {
+	errc := make(chan error)
+	am.quit <- errc
+	return <-errc
+}
+
+// Config returns the configuration of account manager.
+func (am *Manager) Config() *Config {
+	return am.config
+}
+
+// update is the wallet event loop listening for notifications from the backends
+// and updating the cache of wallets.
+func (am *Manager) update() {
+	// Close all subscriptions when the manager terminates
+	defer func() {
+		am.lock.Lock()
+		for _, sub := range am.updaters {
+			sub.Unsubscribe()
+		}
+		am.updaters = nil
+		am.lock.Unlock()
+	}()
+
+	// Loop until termination
+	for {
+		select {
+		case event := <-am.updates:
+			// Wallet event arrived, update local cache
+			am.lock.Lock()
+			switch event.Kind {
+			case WalletArrived:
+				am.wallets = merge(am.wallets, event.Wallet)
+			case WalletDropped:
+				am.wallets = drop(am.wallets, event.Wallet)
+			}
+			am.lock.Unlock()
+
+			// Notify any listeners of the event
+			am.feed.Send(event)
+
+		case errc := <-am.quit:
+			// Manager terminating, return
+			errc <- nil
+			return
+		}
+	}
+}
+
+// Backends retrieves the backend(s) with the given type from the account manager.
+func (am *Manager) Backends(kind reflect.Type) []Backend {
+	return am.backends[kind]
+}
+
+// Wallets returns all signer accounts registered under this account manager.
+func (am *Manager) Wallets() []Wallet {
+	am.lock.RLock()
+	defer am.lock.RUnlock()
+
+	cpy := make([]Wallet, len(am.wallets))
+	copy(cpy, am.wallets)
+	return cpy
+}
+
+// Wallet retrieves the wallet associated with a particular URL.
+func (am *Manager) Wallet(url string) (Wallet, error) {
+	am.lock.RLock()
+	defer am.lock.RUnlock()
+
+	parsed, err := parseURL(url)
+	if err != nil {
+		return nil, err
+	}
+	for _, wallet := range am.Wallets() {
+		if wallet.URL() == parsed {
+			return wallet, nil
+		}
+	}
+	return nil, ErrUnknownWallet
+}
+
+// Find attempts to locate the wallet corresponding to a specific account. Since
+// accounts can be dynamically added to and removed from wallets, this method has
+// a linear runtime in the number of wallets.
+func (am *Manager) Find(account Account) (Wallet, error) {
+	am.lock.RLock()
+	defer am.lock.RUnlock()
+
+	for _, wallet := range am.wallets {
+		if wallet.Contains(account) {
+			return wallet, nil
+		}
+	}
+	return nil, ErrUnknownAccount
+}
+
+// Subscribe creates an async subscription to receive notifications when the
+// manager detects the arrival or departure of a wallet from any of its backends.
+func (am *Manager) Subscribe(sink chan<- WalletEvent) event.Subscription {
+	return am.feed.Subscribe(sink)
+}
+
+// merge is a sorted analogue of append for wallets, where the ordering of the
+// origin list is preserved by inserting new wallets at the correct position.
+//
+// The original slice is assumed to be already sorted by URL.
+func merge(slice []Wallet, wallets ...Wallet) []Wallet {
+	for _, wallet := range wallets {
+		n := sort.Search(len(slice), func(i int) bool { return slice[i].URL().Cmp(wallet.URL()) >= 0 })
+		if n == len(slice) {
+			slice = append(slice, wallet)
+			continue
+		}
+		slice = append(slice[:n], append([]Wallet{wallet}, slice[n:]...)...)
+	}
+	return slice
+}
+
+// drop is the couterpart of merge, which looks up wallets from within the sorted
+// cache and removes the ones specified.
+func drop(slice []Wallet, wallets ...Wallet) []Wallet {
+	for _, wallet := range wallets {
+		n := sort.Search(len(slice), func(i int) bool { return slice[i].URL().Cmp(wallet.URL()) >= 0 })
+		if n == len(slice) {
+			// Wallet not found, may happen during startup
+			continue
+		}
+		slice = append(slice[:n], slice[n+1:]...)
+	}
+	return slice
+}

accounts/scwallet/README.md

@@ -0,0 +1,102 @@
+# Using the smartcard wallet
+
+## Requirements
+
+  * A USB smartcard reader
+  * A keycard that supports the status app
+  * PCSCD version 4.3 running on your system **Only version 4.3 is currently supported**
+
+## Preparing the smartcard
+
+  **WARNING: FOILLOWING THESE INSTRUCTIONS WILL DESTROY THE MASTER KEY ON YOUR CARD. ONLY PROCEED IF NO FUNDS ARE ASSOCIATED WITH THESE ACCOUNTS**
+
+  You can use status' [keycard-cli](https://github.com/status-im/keycard-cli) and you should get _at least_ version 2.1.1 of their [smartcard application](https://github.com/status-im/status-keycard/releases/download/2.2.1/keycard_v2.2.1.cap)
+
+  You also need to make sure that the PCSC daemon is running on your system.
+
+  Then, you can install the application to the card by typing:
+
+  ```
+  keycard install -a keycard_v2.2.1.cap && keycard init
+  ```
+
+  At the end of this process, you will be provided with a PIN, a PUK and a pairing password. Write them down, you'll need them shortly.
+
+  Start `geth` with the `console` command. You will notice the following warning:
+
+  ```
+  WARN [04-09|16:58:38.898] Failed to open wallet                    url=pcsc://044def09                          err="smartcard: pairing password needed"
+  ```
+
+  Write down the URL (`pcsc://044def09` in this example). Then ask `geth` to open the wallet:
+
+  ```
+  > personal.openWallet("pcsc://044def09")
+  Please enter the pairing password:
+  ```
+
+  Enter the pairing password that you have received during card initialization. Same with the PIN that you will subsequently be
+  asked for.
+  
+  If everything goes well, you should see your new account when typing `personal` on the console:
+
+  ```
+  > personal
+  WARN [04-09|17:02:07.330] Smartcard wallet account derivation failed url=pcsc://044def09 err="Unexpected response status Cla=0x80, Ins=0xd1, Sw=0x6985"
+  {
+    listAccounts: [],
+    listWallets: [{
+        status: "Empty, waiting for initialization",
+        url: "pcsc://044def09"
+    }],
+    ...
+  }
+  ```
+
+  So the communication with the card is working, but there is no key associated with this wallet. Let's create it:
+
+  ```
+  > personal.initializeWallet("pcsc://044def09")
+  "tilt ... impact"
+  ```
+
+  You should get a list of words, this is your seed so write them down. Your wallet should now be initialized:
+
+  ```
+  > personal.listWallets
+  [{
+    accounts: [{
+        address: "0x678b7cd55c61917defb23546a41803c5bfefbc7a",
+        url: "pcsc://044d/m/44'/60'/0'/0/0"
+    }],
+    status: "Online",
+    url: "pcsc://044def09"
+  }]
+  ```
+
+  You're all set!
+
+## Usage
+
+  1. Start `geth` with the `console` command
+  2. Check the card's URL by checking `personal.listWallets`:
+
+```
+  listWallets: [{
+      status: "Online, can derive public keys",
+      url: "pcsc://a4d73015"
+  }]
+```
+
+  3. Open the wallet, you will be prompted for your pairing password, then PIN:
+
+```
+personal.openWallet("pcsc://a4d73015")
+```
+
+  4. Check that creation was successful by typing e.g. `personal`. Then use it like a regular wallet.
+
+## Known issues
+
+  * Starting geth with a valid card seems to make firefox crash.
+  * PCSC version 4.4 should work, but is currently untested

accounts/scwallet/apdu.go

@@ -0,0 +1,87 @@
+// Copyright 2018 The go-ethereum Authors
+// This file is part of the go-ethereum library.
+//
+// The go-ethereum library is free software: you can redistribute it and/or modify
+// it under the terms of the GNU Lesser General Public License as published by
+// the Free Software Foundation, either version 3 of the License, or
+// (at your option) any later version.
+//
+// The go-ethereum library is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+// GNU Lesser General Public License for more details.
+//
+// You should have received a copy of the GNU Lesser General Public License
+// along with the go-ethereum library. If not, see <http://www.gnu.org/licenses/>.
+
+package scwallet
+
+import (
+	"bytes"
+	"encoding/binary"
+	"fmt"
+)
+
+// commandAPDU represents an application data unit sent to a smartcard.
+type commandAPDU struct {
+	Cla, Ins, P1, P2 uint8  // Class, Instruction, Parameter 1, Parameter 2
+	Data             []byte // Command data
+	Le               uint8  // Command data length
+}
+
+// serialize serializes a command APDU.
+func (ca commandAPDU) serialize() ([]byte, error) {
+	buf := new(bytes.Buffer)
+
+	if err := binary.Write(buf, binary.BigEndian, ca.Cla); err != nil {
+		return nil, err
+	}
+	if err := binary.Write(buf, binary.BigEndian, ca.Ins); err != nil {
+		return nil, err
+	}
+	if err := binary.Write(buf, binary.BigEndian, ca.P1); err != nil {
+		return nil, err
+	}
+	if err := binary.Write(buf, binary.BigEndian, ca.P2); err != nil {
+		return nil, err
+	}
+	if len(ca.Data) > 0 {
+		if err := binary.Write(buf, binary.BigEndian, uint8(len(ca.Data))); err != nil {
+			return nil, err
+		}
+		if err := binary.Write(buf, binary.BigEndian, ca.Data); err != nil {
+			return nil, err
+		}
+	}
+	if err := binary.Write(buf, binary.BigEndian, ca.Le); err != nil {
+		return nil, err
+	}
+	return buf.Bytes(), nil
+}
+
+// responseAPDU represents an application data unit received from a smart card.
+type responseAPDU struct {
+	Data     []byte // response data
+	Sw1, Sw2 uint8  // status words 1 and 2
+}
+
+// deserialize deserializes a response APDU.
+func (ra *responseAPDU) deserialize(data []byte) error {
+	if len(data) < 2 {
+		return fmt.Errorf("can not deserialize data: payload too short (%d < 2)", len(data))
+	}
+
+	ra.Data = make([]byte, len(data)-2)
+
+	buf := bytes.NewReader(data)
+	if err := binary.Read(buf, binary.BigEndian, &ra.Data); err != nil {
+		return err
+	}
+	if err := binary.Read(buf, binary.BigEndian, &ra.Sw1); err != nil {
+		return err
+	}
+	if err := binary.Read(buf, binary.BigEndian, &ra.Sw2); err != nil {
+		return err
+	}
+	return nil
+}

accounts/scwallet/hub.go

@@ -0,0 +1,302 @@
+// Copyright 2018 The go-ethereum Authors
+// This file is part of the go-ethereum library.
+//
+// The go-ethereum library is free software: you can redistribute it and/or modify
+// it under the terms of the GNU Lesser General Public License as published by
+// the Free Software Foundation, either version 3 of the License, or
+// (at your option) any later version.
+//
+// The go-ethereum library is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+// GNU Lesser General Public License for more details.
+//
+// You should have received a copy of the GNU Lesser General Public License
+// along with the go-ethereum library. If not, see <http://www.gnu.org/licenses/>.
+
+// This package implements support for smartcard-based hardware wallets such as
+// the one written by Status: https://github.com/status-im/hardware-wallet
+//
+// This implementation of smartcard wallets have a different interaction process
+// to other types of hardware wallet. The process works like this:
+//
+// 1. (First use with a given client) Establish a pairing between hardware
+//    wallet and client. This requires a secret value called a 'pairing password'.
+//    You can pair with an unpaired wallet with `personal.openWallet(URI, pairing password)`.
+// 2. (First use only) Initialize the wallet, which generates a keypair, stores
+//    it on the wallet, and returns it so the user can back it up. You can
+//    initialize a wallet with `personal.initializeWallet(URI)`.
+// 3. Connect to the wallet using the pairing information established in step 1.
+//    You can connect to a paired wallet with `personal.openWallet(URI, PIN)`.
+// 4. Interact with the wallet as normal.
+
+package scwallet
+
+import (
+	"encoding/json"
+	"io/ioutil"
+	"os"
+	"path/filepath"
+	"sort"
+	"sync"
+	"time"
+
+	"github.com/ethereum/go-ethereum/accounts"
+	"github.com/ethereum/go-ethereum/common"
+	"github.com/ethereum/go-ethereum/event"
+	"github.com/ethereum/go-ethereum/log"
+	pcsc "github.com/gballet/go-libpcsclite"
+)
+
+// Scheme is the URI prefix for smartcard wallets.
+const Scheme = "pcsc"
+
+// refreshCycle is the maximum time between wallet refreshes (if USB hotplug
+// notifications don't work).
+const refreshCycle = time.Second
+
+// refreshThrottling is the minimum time between wallet refreshes to avoid thrashing.
+const refreshThrottling = 500 * time.Millisecond
+
+// smartcardPairing contains information about a smart card we have paired with
+// or might pair with the hub.
+type smartcardPairing struct {
+	PublicKey    []byte                                     `json:"publicKey"`
+	PairingIndex uint8                                      `json:"pairingIndex"`
+	PairingKey   []byte                                     `json:"pairingKey"`
+	Accounts     map[common.Address]accounts.DerivationPath `json:"accounts"`
+}
+
+// Hub is a accounts.Backend that can find and handle generic PC/SC hardware wallets.
+type Hub struct {
+	scheme string // Protocol scheme prefixing account and wallet URLs.
+
+	context  *pcsc.Client
+	datadir  string
+	pairings map[string]smartcardPairing
+
+	refreshed   time.Time               // Time instance when the list of wallets was last refreshed
+	wallets     map[string]*Wallet      // Mapping from reader names to wallet instances
+	updateFeed  event.Feed              // Event feed to notify wallet additions/removals
+	updateScope event.SubscriptionScope // Subscription scope tracking current live listeners
+	updating    bool                    // Whether the event notification loop is running
+
+	quit chan chan error
+
+	stateLock sync.RWMutex // Protects the internals of the hub from racey access
+}
+
+func (hub *Hub) readPairings() error {
+	hub.pairings = make(map[string]smartcardPairing)
+	pairingFile, err := os.Open(filepath.Join(hub.datadir, "smartcards.json"))
+	if err != nil {
+		if os.IsNotExist(err) {
+			return nil
+		}
+		return err
+	}
+
+	pairingData, err := ioutil.ReadAll(pairingFile)
+	if err != nil {
+		return err
+	}
+	var pairings []smartcardPairing
+	if err := json.Unmarshal(pairingData, &pairings); err != nil {
+		return err
+	}
+
+	for _, pairing := range pairings {
+		hub.pairings[string(pairing.PublicKey)] = pairing
+	}
+	return nil
+}
+
+func (hub *Hub) writePairings() error {
+	pairingFile, err := os.OpenFile(filepath.Join(hub.datadir, "smartcards.json"), os.O_RDWR|os.O_CREATE, 0755)
+	if err != nil {
+		return err
+	}
+	defer pairingFile.Close()
+
+	pairings := make([]smartcardPairing, 0, len(hub.pairings))
+	for _, pairing := range hub.pairings {
+		pairings = append(pairings, pairing)
+	}
+
+	pairingData, err := json.Marshal(pairings)
+	if err != nil {
+		return err
+	}
+
+	if _, err := pairingFile.Write(pairingData); err != nil {
+		return err
+	}
+
+	return nil
+}
+
+func (hub *Hub) pairing(wallet *Wallet) *smartcardPairing {
+	if pairing, ok := hub.pairings[string(wallet.PublicKey)]; ok {
+		return &pairing
+	}
+	return nil
+}
+
+func (hub *Hub) setPairing(wallet *Wallet, pairing *smartcardPairing) error {
+	if pairing == nil {
+		delete(hub.pairings, string(wallet.PublicKey))
+	} else {
+		hub.pairings[string(wallet.PublicKey)] = *pairing
+	}
+	return hub.writePairings()
+}
+
+// NewHub creates a new hardware wallet manager for smartcards.
+func NewHub(scheme string, datadir string) (*Hub, error) {
+	context, err := pcsc.EstablishContext(pcsc.ScopeSystem)
+	if err != nil {
+		return nil, err
+	}
+	hub := &Hub{
+		scheme:  scheme,
+		context: context,
+		datadir: datadir,
+		wallets: make(map[string]*Wallet),
+		quit:    make(chan chan error),
+	}
+	if err := hub.readPairings(); err != nil {
+		return nil, err
+	}
+	hub.refreshWallets()
+	return hub, nil
+}
+
+// Wallets implements accounts.Backend, returning all the currently tracked smart
+// cards that appear to be hardware wallets.
+func (hub *Hub) Wallets() []accounts.Wallet {
+	// Make sure the list of wallets is up to date
+	hub.refreshWallets()
+
+	hub.stateLock.RLock()
+	defer hub.stateLock.RUnlock()
+
+	cpy := make([]accounts.Wallet, 0, len(hub.wallets))
+	for _, wallet := range hub.wallets {
+		cpy = append(cpy, wallet)
+	}
+	sort.Sort(accounts.WalletsByURL(cpy))
+	return cpy
+}
+
+// refreshWallets scans the devices attached to the machine and updates the
+// list of wallets based on the found devices.
+func (hub *Hub) refreshWallets() {
+	// Don't scan the USB like crazy it the user fetches wallets in a loop
+	hub.stateLock.RLock()
+	elapsed := time.Since(hub.refreshed)
+	hub.stateLock.RUnlock()
+
+	if elapsed < refreshThrottling {
+		return
+	}
+	// Retrieve all the smart card reader to check for cards
+	readers, err := hub.context.ListReaders()
+	if err != nil {
+		// This is a perverted hack, the scard library returns an error if no card
+		// readers are present instead of simply returning an empty list. We don't
+		// want to fill the user's log with errors, so filter those out.
+		if err.Error() != "scard: Cannot find a smart card reader." {
+			log.Error("Failed to enumerate smart card readers", "err", err)
+			return
+		}
+	}
+	// Transform the current list of wallets into the new one
+	hub.stateLock.Lock()
+
+	events := []accounts.WalletEvent{}
+	seen := make(map[string]struct{})
+
+	for _, reader := range readers {
+		// Mark the reader as present
+		seen[reader] = struct{}{}
+
+		// If we alreay know about this card, skip to the next reader, otherwise clean up
+		if wallet, ok := hub.wallets[reader]; ok {
+			if err := wallet.ping(); err == nil {
+				continue
+			}
+			wallet.Close()
+			events = append(events, accounts.WalletEvent{Wallet: wallet, Kind: accounts.WalletDropped})
+			delete(hub.wallets, reader)
+		}
+		// New card detected, try to connect to it
+		card, err := hub.context.Connect(reader, pcsc.ShareShared, pcsc.ProtocolAny)
+		if err != nil {
+			log.Debug("Failed to open smart card", "reader", reader, "err", err)
+			continue
+		}
+		wallet := NewWallet(hub, card)
+		if err = wallet.connect(); err != nil {
+			log.Debug("Failed to connect to smart card", "reader", reader, "err", err)
+			card.Disconnect(pcsc.LeaveCard)
+			continue
+		}
+		// Card connected, start tracking in amongs the wallets
+		hub.wallets[reader] = wallet
+		events = append(events, accounts.WalletEvent{Wallet: wallet, Kind: accounts.WalletArrived})
+	}
+	// Remove any wallets no longer present
+	for reader, wallet := range hub.wallets {
+		if _, ok := seen[reader]; !ok {
+			wallet.Close()
+			events = append(events, accounts.WalletEvent{Wallet: wallet, Kind: accounts.WalletDropped})
+			delete(hub.wallets, reader)
+		}
+	}
+	hub.refreshed = time.Now()
+	hub.stateLock.Unlock()
+
+	for _, event := range events {
+		hub.updateFeed.Send(event)
+	}
+}
+
+// Subscribe implements accounts.Backend, creating an async subscription to
+// receive notifications on the addition or removal of smart card wallets.
+func (hub *Hub) Subscribe(sink chan<- accounts.WalletEvent) event.Subscription {
+	// We need the mutex to reliably start/stop the update loop
+	hub.stateLock.Lock()
+	defer hub.stateLock.Unlock()
+
+	// Subscribe the caller and track the subscriber count
+	sub := hub.updateScope.Track(hub.updateFeed.Subscribe(sink))
+
+	// Subscribers require an active notification loop, start it
+	if !hub.updating {
+		hub.updating = true
+		go hub.updater()
+	}
+	return sub
+}
+
+// updater is responsible for maintaining an up-to-date list of wallets managed
+// by the smart card hub, and for firing wallet addition/removal events.
+func (hub *Hub) updater() {
+	for {
+		// TODO: Wait for a USB hotplug event (not supported yet) or a refresh timeout
+		// <-hub.changes
+		time.Sleep(refreshCycle)
+
+		// Run the wallet refresher
+		hub.refreshWallets()
+
+		// If all our subscribers left, stop the updater
+		hub.stateLock.Lock()
+		if hub.updateScope.Count() == 0 {
+			hub.updating = false
+			hub.stateLock.Unlock()
+			return
+		}
+		hub.stateLock.Unlock()
+	}
+}

accounts/scwallet/securechannel.go

@@ -0,0 +1,346 @@
+// Copyright 2018 The go-ethereum Authors
+// This file is part of the go-ethereum library.
+//
+// The go-ethereum library is free software: you can redistribute it and/or modify
+// it under the terms of the GNU Lesser General Public License as published by
+// the Free Software Foundation, either version 3 of the License, or
+// (at your option) any later version.
+//
+// The go-ethereum library is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+// GNU Lesser General Public License for more details.
+//
+// You should have received a copy of the GNU Lesser General Public License
+// along with the go-ethereum library. If not, see <http://www.gnu.org/licenses/>.
+
+package scwallet
+
+import (
+	"bytes"
+	"crypto/aes"
+	"crypto/cipher"
+	"crypto/rand"
+	"crypto/sha256"
+	"crypto/sha512"
+	"fmt"
+
+	"github.com/ethereum/go-ethereum/crypto"
+	pcsc "github.com/gballet/go-libpcsclite"
+	"github.com/wsddn/go-ecdh"
+	"golang.org/x/crypto/pbkdf2"
+	"golang.org/x/text/unicode/norm"
+)
+
+const (
+	maxPayloadSize  = 223
+	pairP1FirstStep = 0
+	pairP1LastStep  = 1
+
+	scSecretLength = 32
+	scBlockSize    = 16
+
+	insOpenSecureChannel    = 0x10
+	insMutuallyAuthenticate = 0x11
+	insPair                 = 0x12
+	insUnpair               = 0x13
+
+	pairingSalt = "Keycard Pairing Password Salt"
+)
+
+// SecureChannelSession enables secure communication with a hardware wallet.
+type SecureChannelSession struct {
+	card          *pcsc.Card // A handle to the smartcard for communication
+	secret        []byte     // A shared secret generated from our ECDSA keys
+	publicKey     []byte     // Our own ephemeral public key
+	PairingKey    []byte     // A permanent shared secret for a pairing, if present
+	sessionEncKey []byte     // The current session encryption key
+	sessionMacKey []byte     // The current session MAC key
+	iv            []byte     // The current IV
+	PairingIndex  uint8      // The pairing index
+}
+
+// NewSecureChannelSession creates a new secure channel for the given card and public key.
+func NewSecureChannelSession(card *pcsc.Card, keyData []byte) (*SecureChannelSession, error) {
+	// Generate an ECDSA keypair for ourselves
+	gen := ecdh.NewEllipticECDH(crypto.S256())
+	private, public, err := gen.GenerateKey(rand.Reader)
+	if err != nil {
+		return nil, err
+	}
+
+	cardPublic, ok := gen.Unmarshal(keyData)
+	if !ok {
+		return nil, fmt.Errorf("Could not unmarshal public key from card")
+	}
+
+	secret, err := gen.GenerateSharedSecret(private, cardPublic)
+	if err != nil {
+		return nil, err
+	}
+
+	return &SecureChannelSession{
+		card:      card,
+		secret:    secret,
+		publicKey: gen.Marshal(public),
+	}, nil
+}
+
+// Pair establishes a new pairing with the smartcard.
+func (s *SecureChannelSession) Pair(pairingPassword []byte) error {
+	secretHash := pbkdf2.Key(norm.NFKD.Bytes(pairingPassword), norm.NFKD.Bytes([]byte(pairingSalt)), 50000, 32, sha256.New)
+
+	challenge := make([]byte, 32)
+	if _, err := rand.Read(challenge); err != nil {
+		return err
+	}
+
+	response, err := s.pair(pairP1FirstStep, challenge)
+	if err != nil {
+		return err
+	}
+
+	md := sha256.New()
+	md.Write(secretHash[:])
+	md.Write(challenge)
+
+	expectedCryptogram := md.Sum(nil)
+	cardCryptogram := response.Data[:32]
+	cardChallenge := response.Data[32:64]
+
+	if !bytes.Equal(expectedCryptogram, cardCryptogram) {
+		return fmt.Errorf("Invalid card cryptogram %v != %v", expectedCryptogram, cardCryptogram)
+	}
+
+	md.Reset()
+	md.Write(secretHash[:])
+	md.Write(cardChallenge)
+	response, err = s.pair(pairP1LastStep, md.Sum(nil))
+	if err != nil {
+		return err
+	}
+
+	md.Reset()
+	md.Write(secretHash[:])
+	md.Write(response.Data[1:])
+	s.PairingKey = md.Sum(nil)
+	s.PairingIndex = response.Data[0]
+
+	return nil
+}
+
+// Unpair disestablishes an existing pairing.
+func (s *SecureChannelSession) Unpair() error {
+	if s.PairingKey == nil {
+		return fmt.Errorf("Cannot unpair: not paired")
+	}
+
+	_, err := s.transmitEncrypted(claSCWallet, insUnpair, s.PairingIndex, 0, []byte{})
+	if err != nil {
+		return err
+	}
+	s.PairingKey = nil
+	// Close channel
+	s.iv = nil
+	return nil
+}
+
+// Open initializes the secure channel.
+func (s *SecureChannelSession) Open() error {
+	if s.iv != nil {
+		return fmt.Errorf("Session already opened")
+	}
+
+	response, err := s.open()
+	if err != nil {
+		return err
+	}
+
+	// Generate the encryption/mac key by hashing our shared secret,
+	// pairing key, and the first bytes returned from the Open APDU.
+	md := sha512.New()
+	md.Write(s.secret)
+	md.Write(s.PairingKey)
+	md.Write(response.Data[:scSecretLength])
+	keyData := md.Sum(nil)
+	s.sessionEncKey = keyData[:scSecretLength]
+	s.sessionMacKey = keyData[scSecretLength : scSecretLength*2]
+
+	// The IV is the last bytes returned from the Open APDU.
+	s.iv = response.Data[scSecretLength:]
+
+	return s.mutuallyAuthenticate()
+}
+
+// mutuallyAuthenticate is an internal method to authenticate both ends of the
+// connection.
+func (s *SecureChannelSession) mutuallyAuthenticate() error {
+	data := make([]byte, scSecretLength)
+	if _, err := rand.Read(data); err != nil {
+		return err
+	}
+
+	response, err := s.transmitEncrypted(claSCWallet, insMutuallyAuthenticate, 0, 0, data)
+	if err != nil {
+		return err
+	}
+	if response.Sw1 != 0x90 || response.Sw2 != 0x00 {
+		return fmt.Errorf("Got unexpected response from MUTUALLY_AUTHENTICATE: 0x%x%x", response.Sw1, response.Sw2)
+	}
+
+	if len(response.Data) != scSecretLength {
+		return fmt.Errorf("Response from MUTUALLY_AUTHENTICATE was %d bytes, expected %d", len(response.Data), scSecretLength)
+	}
+
+	return nil
+}
+
+// open is an internal method that sends an open APDU.
+func (s *SecureChannelSession) open() (*responseAPDU, error) {
+	return transmit(s.card, &commandAPDU{
+		Cla:  claSCWallet,
+		Ins:  insOpenSecureChannel,
+		P1:   s.PairingIndex,
+		P2:   0,
+		Data: s.publicKey,
+		Le:   0,
+	})
+}
+
+// pair is an internal method that sends a pair APDU.
+func (s *SecureChannelSession) pair(p1 uint8, data []byte) (*responseAPDU, error) {
+	return transmit(s.card, &commandAPDU{
+		Cla:  claSCWallet,
+		Ins:  insPair,
+		P1:   p1,
+		P2:   0,
+		Data: data,
+		Le:   0,
+	})
+}
+
+// transmitEncrypted sends an encrypted message, and decrypts and returns the response.
+func (s *SecureChannelSession) transmitEncrypted(cla, ins, p1, p2 byte, data []byte) (*responseAPDU, error) {
+	if s.iv == nil {
+		return nil, fmt.Errorf("Channel not open")
+	}
+
+	data, err := s.encryptAPDU(data)
+	if err != nil {
+		return nil, err
+	}
+	meta := [16]byte{cla, ins, p1, p2, byte(len(data) + scBlockSize)}
+	if err = s.updateIV(meta[:], data); err != nil {
+		return nil, err
+	}
+
+	fulldata := make([]byte, len(s.iv)+len(data))
+	copy(fulldata, s.iv)
+	copy(fulldata[len(s.iv):], data)
+
+	response, err := transmit(s.card, &commandAPDU{
+		Cla:  cla,
+		Ins:  ins,
+		P1:   p1,
+		P2:   p2,
+		Data: fulldata,
+	})
+	if err != nil {
+		return nil, err
+	}
+
+	rmeta := [16]byte{byte(len(response.Data))}
+	rmac := response.Data[:len(s.iv)]
+	rdata := response.Data[len(s.iv):]
+	plainData, err := s.decryptAPDU(rdata)
+	if err != nil {
+		return nil, err
+	}
+
+	if err = s.updateIV(rmeta[:], rdata); err != nil {
+		return nil, err
+	}
+	if !bytes.Equal(s.iv, rmac) {
+		return nil, fmt.Errorf("Invalid MAC in response")
+	}
+
+	rapdu := &responseAPDU{}
+	rapdu.deserialize(plainData)
+
+	if rapdu.Sw1 != sw1Ok {
+		return nil, fmt.Errorf("Unexpected response status Cla=0x%x, Ins=0x%x, Sw=0x%x%x", cla, ins, rapdu.Sw1, rapdu.Sw2)
+	}
+
+	return rapdu, nil
+}
+
+// encryptAPDU is an internal method that serializes and encrypts an APDU.
+func (s *SecureChannelSession) encryptAPDU(data []byte) ([]byte, error) {
+	if len(data) > maxPayloadSize {
+		return nil, fmt.Errorf("Payload of %d bytes exceeds maximum of %d", len(data), maxPayloadSize)
+	}
+	data = pad(data, 0x80)
+
+	ret := make([]byte, len(data))
+
+	a, err := aes.NewCipher(s.sessionEncKey)
+	if err != nil {
+		return nil, err
+	}
+	crypter := cipher.NewCBCEncrypter(a, s.iv)
+	crypter.CryptBlocks(ret, data)
+	return ret, nil
+}
+
+// pad applies message padding to a 16 byte boundary.
+func pad(data []byte, terminator byte) []byte {
+	padded := make([]byte, (len(data)/16+1)*16)
+	copy(padded, data)
+	padded[len(data)] = terminator
+	return padded
+}
+
+// decryptAPDU is an internal method that decrypts and deserializes an APDU.
+func (s *SecureChannelSession) decryptAPDU(data []byte) ([]byte, error) {
+	a, err := aes.NewCipher(s.sessionEncKey)
+	if err != nil {
+		return nil, err
+	}
+
+	ret := make([]byte, len(data))
+
+	crypter := cipher.NewCBCDecrypter(a, s.iv)
+	crypter.CryptBlocks(ret, data)
+	return unpad(ret, 0x80)
+}
+
+// unpad strips padding from a message.
+func unpad(data []byte, terminator byte) ([]byte, error) {
+	for i := 1; i <= 16; i++ {
+		switch data[len(data)-i] {
+		case 0:
+			continue
+		case terminator:
+			return data[:len(data)-i], nil
+		default:
+			return nil, fmt.Errorf("Expected end of padding, got %d", data[len(data)-i])
+		}
+	}
+	return nil, fmt.Errorf("Expected end of padding, got 0")
+}
+
+// updateIV is an internal method that updates the initialization vector after
+// each message exchanged.
+func (s *SecureChannelSession) updateIV(meta, data []byte) error {
+	data = pad(data, 0)
+	a, err := aes.NewCipher(s.sessionMacKey)
+	if err != nil {
+		return err
+	}
+	crypter := cipher.NewCBCEncrypter(a, make([]byte, 16))
+	crypter.CryptBlocks(meta, meta)
+	crypter.CryptBlocks(data, data)
+	// The first 16 bytes of the last block is the MAC
+	s.iv = data[len(data)-32 : len(data)-16]
+	return nil
+}

accounts/sort.go

@@ -0,0 +1,31 @@
+// Copyright 2018 The go-ethereum Authors
+// This file is part of the go-ethereum library.
+//
+// The go-ethereum library is free software: you can redistribute it and/or modify
+// it under the terms of the GNU Lesser General Public License as published by
+// the Free Software Foundation, either version 3 of the License, or
+// (at your option) any later version.
+//
+// The go-ethereum library is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+// GNU Lesser General Public License for more details.
+//
+// You should have received a copy of the GNU Lesser General Public License
+// along with the go-ethereum library. If not, see <http://www.gnu.org/licenses/>.
+
+package accounts
+
+// AccountsByURL implements sort.Interface for []Account based on the URL field.
+type AccountsByURL []Account
+
+func (a AccountsByURL) Len() int           { return len(a) }
+func (a AccountsByURL) Swap(i, j int)      { a[i], a[j] = a[j], a[i] }
+func (a AccountsByURL) Less(i, j int) bool { return a[i].URL.Cmp(a[j].URL) < 0 }
+
+// WalletsByURL implements sort.Interface for []Wallet based on the URL field.
+type WalletsByURL []Wallet
+
+func (w WalletsByURL) Len() int           { return len(w) }
+func (w WalletsByURL) Swap(i, j int)      { w[i], w[j] = w[j], w[i] }
+func (w WalletsByURL) Less(i, j int) bool { return w[i].URL().Cmp(w[j].URL()) < 0 }

accounts/url.go

@@ -0,0 +1,104 @@
+// Copyright 2017 The go-ethereum Authors
+// This file is part of the go-ethereum library.
+//
+// The go-ethereum library is free software: you can redistribute it and/or modify
+// it under the terms of the GNU Lesser General Public License as published by
+// the Free Software Foundation, either version 3 of the License, or
+// (at your option) any later version.
+//
+// The go-ethereum library is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+// GNU Lesser General Public License for more details.
+//
+// You should have received a copy of the GNU Lesser General Public License
+// along with the go-ethereum library. If not, see <http://www.gnu.org/licenses/>.
+
+package accounts
+
+import (
+	"encoding/json"
+	"errors"
+	"fmt"
+	"strings"
+)
+
+// URL represents the canonical identification URL of a wallet or account.
+//
+// It is a simplified version of url.URL, with the important limitations (which
+// are considered features here) that it contains value-copyable components only,
+// as well as that it doesn't do any URL encoding/decoding of special characters.
+//
+// The former is important to allow an account to be copied without leaving live
+// references to the original version, whereas the latter is important to ensure
+// one single canonical form opposed to many allowed ones by the RFC 3986 spec.
+//
+// As such, these URLs should not be used outside of the scope of an Ethereum
+// wallet or account.
+type URL struct {
+	Scheme string // Protocol scheme to identify a capable account backend
+	Path   string // Path for the backend to identify a unique entity
+}
+
+// parseURL converts a user supplied URL into the accounts specific structure.
+func parseURL(url string) (URL, error) {
+	parts := strings.Split(url, "://")
+	if len(parts) != 2 || parts[0] == "" {
+		return URL{}, errors.New("protocol scheme missing")
+	}
+	return URL{
+		Scheme: parts[0],
+		Path:   parts[1],
+	}, nil
+}
+
+// String implements the stringer interface.
+func (u URL) String() string {
+	if u.Scheme != "" {
+		return fmt.Sprintf("%s://%s", u.Scheme, u.Path)
+	}
+	return u.Path
+}
+
+// TerminalString implements the log.TerminalStringer interface.
+func (u URL) TerminalString() string {
+	url := u.String()
+	if len(url) > 32 {
+		return url[:31] + "…"
+	}
+	return url
+}
+
+// MarshalJSON implements the json.Marshaller interface.
+func (u URL) MarshalJSON() ([]byte, error) {
+	return json.Marshal(u.String())
+}
+
+// UnmarshalJSON parses url.
+func (u *URL) UnmarshalJSON(input []byte) error {
+	var textURL string
+	err := json.Unmarshal(input, &textURL)
+	if err != nil {
+		return err
+	}
+	url, err := parseURL(textURL)
+	if err != nil {
+		return err
+	}
+	u.Scheme = url.Scheme
+	u.Path = url.Path
+	return nil
+}
+
+// Cmp compares x and y and returns:
+//
+//   -1 if x <  y
+//    0 if x == y
+//   +1 if x >  y
+//
+func (u URL) Cmp(url URL) int {
+	if u.Scheme == url.Scheme {
+		return strings.Compare(u.Path, url.Path)
+	}
+	return strings.Compare(u.Scheme, url.Scheme)
+}

accounts/url_test.go

@@ -0,0 +1,96 @@
+// Copyright 2017 The go-ethereum Authors
+// This file is part of the go-ethereum library.
+//
+// The go-ethereum library is free software: you can redistribute it and/or modify
+// it under the terms of the GNU Lesser General Public License as published by
+// the Free Software Foundation, either version 3 of the License, or
+// (at your option) any later version.
+//
+// The go-ethereum library is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+// GNU Lesser General Public License for more details.
+//
+// You should have received a copy of the GNU Lesser General Public License
+// along with the go-ethereum library. If not, see <http://www.gnu.org/licenses/>.
+
+package accounts
+
+import (
+	"testing"
+)
+
+func TestURLParsing(t *testing.T) {
+	url, err := parseURL("https://ethereum.org")
+	if err != nil {
+		t.Errorf("unexpected error: %v", err)
+	}
+	if url.Scheme != "https" {
+		t.Errorf("expected: %v, got: %v", "https", url.Scheme)
+	}
+	if url.Path != "ethereum.org" {
+		t.Errorf("expected: %v, got: %v", "ethereum.org", url.Path)
+	}
+
+	_, err = parseURL("ethereum.org")
+	if err == nil {
+		t.Error("expected err, got: nil")
+	}
+}
+
+func TestURLString(t *testing.T) {
+	url := URL{Scheme: "https", Path: "ethereum.org"}
+	if url.String() != "https://ethereum.org" {
+		t.Errorf("expected: %v, got: %v", "https://ethereum.org", url.String())
+	}
+
+	url = URL{Scheme: "", Path: "ethereum.org"}
+	if url.String() != "ethereum.org" {
+		t.Errorf("expected: %v, got: %v", "ethereum.org", url.String())
+	}
+}
+
+func TestURLMarshalJSON(t *testing.T) {
+	url := URL{Scheme: "https", Path: "ethereum.org"}
+	json, err := url.MarshalJSON()
+	if err != nil {
+		t.Errorf("unexpcted error: %v", err)
+	}
+	if string(json) != "\"https://ethereum.org\"" {
+		t.Errorf("expected: %v, got: %v", "\"https://ethereum.org\"", string(json))
+	}
+}
+
+func TestURLUnmarshalJSON(t *testing.T) {
+	url := &URL{}
+	err := url.UnmarshalJSON([]byte("\"https://ethereum.org\""))
+	if err != nil {
+		t.Errorf("unexpcted error: %v", err)
+	}
+	if url.Scheme != "https" {
+		t.Errorf("expected: %v, got: %v", "https", url.Scheme)
+	}
+	if url.Path != "ethereum.org" {
+		t.Errorf("expected: %v, got: %v", "https", url.Path)
+	}
+}
+
+func TestURLComparison(t *testing.T) {
+	tests := []struct {
+		urlA   URL
+		urlB   URL
+		expect int
+	}{
+		{URL{"https", "ethereum.org"}, URL{"https", "ethereum.org"}, 0},
+		{URL{"http", "ethereum.org"}, URL{"https", "ethereum.org"}, -1},
+		{URL{"https", "ethereum.org/a"}, URL{"https", "ethereum.org"}, 1},
+		{URL{"https", "abc.org"}, URL{"https", "ethereum.org"}, -1},
+	}
+
+	for i, tt := range tests {
+		result := tt.urlA.Cmp(tt.urlB)
+		if result != tt.expect {
+			t.Errorf("test %d: cmp mismatch: expected: %d, got: %d", i, tt.expect, result)
+		}
+	}
+}

accounts/usbwallet/hub.go

@@ -0,0 +1,240 @@
+// Copyright 2017 The go-ethereum Authors
+// This file is part of the go-ethereum library.
+//
+// The go-ethereum library is free software: you can redistribute it and/or modify
+// it under the terms of the GNU Lesser General Public License as published by
+// the Free Software Foundation, either version 3 of the License, or
+// (at your option) any later version.
+//
+// The go-ethereum library is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+// GNU Lesser General Public License for more details.
+//
+// You should have received a copy of the GNU Lesser General Public License
+// along with the go-ethereum library. If not, see <http://www.gnu.org/licenses/>.
+
+package usbwallet
+
+import (
+	"errors"
+	"runtime"
+	"sync"
+	"time"
+
+	"github.com/ethereum/go-ethereum/accounts"
+	"github.com/ethereum/go-ethereum/event"
+	"github.com/ethereum/go-ethereum/log"
+	"github.com/karalabe/hid"
+)
+
+// LedgerScheme is the protocol scheme prefixing account and wallet URLs.
+const LedgerScheme = "ledger"
+
+// TrezorScheme is the protocol scheme prefixing account and wallet URLs.
+const TrezorScheme = "trezor"
+
+// refreshCycle is the maximum time between wallet refreshes (if USB hotplug
+// notifications don't work).
+const refreshCycle = time.Second
+
+// refreshThrottling is the minimum time between wallet refreshes to avoid USB
+// trashing.
+const refreshThrottling = 500 * time.Millisecond
+
+// Hub is a accounts.Backend that can find and handle generic USB hardware wallets.
+type Hub struct {
+	scheme     string                  // Protocol scheme prefixing account and wallet URLs.
+	vendorID   uint16                  // USB vendor identifier used for device discovery
+	productIDs []uint16                // USB product identifiers used for device discovery
+	usageID    uint16                  // USB usage page identifier used for macOS device discovery
+	endpointID int                     // USB endpoint identifier used for non-macOS device discovery
+	makeDriver func(log.Logger) driver // Factory method to construct a vendor specific driver
+
+	refreshed   time.Time               // Time instance when the list of wallets was last refreshed
+	wallets     []accounts.Wallet       // List of USB wallet devices currently tracking
+	updateFeed  event.Feed              // Event feed to notify wallet additions/removals
+	updateScope event.SubscriptionScope // Subscription scope tracking current live listeners
+	updating    bool                    // Whether the event notification loop is running
+
+	quit chan chan error
+
+	stateLock sync.RWMutex // Protects the internals of the hub from racey access
+
+	// TODO(karalabe): remove if hotplug lands on Windows
+	commsPend int        // Number of operations blocking enumeration
+	commsLock sync.Mutex // Lock protecting the pending counter and enumeration
+}
+
+// NewLedgerHub creates a new hardware wallet manager for Ledger devices.
+func NewLedgerHub() (*Hub, error) {
+	return newHub(LedgerScheme, 0x2c97, []uint16{0x0000 /* Ledger Blue */, 0x0001 /* Ledger Nano S */}, 0xffa0, 0, newLedgerDriver)
+}
+
+// NewTrezorHub creates a new hardware wallet manager for Trezor devices.
+func NewTrezorHub() (*Hub, error) {
+	return newHub(TrezorScheme, 0x534c, []uint16{0x0001 /* Trezor 1 */}, 0xff00, 0, newTrezorDriver)
+}
+
+// newHub creates a new hardware wallet manager for generic USB devices.
+func newHub(scheme string, vendorID uint16, productIDs []uint16, usageID uint16, endpointID int, makeDriver func(log.Logger) driver) (*Hub, error) {
+	if !hid.Supported() {
+		return nil, errors.New("unsupported platform")
+	}
+	hub := &Hub{
+		scheme:     scheme,
+		vendorID:   vendorID,
+		productIDs: productIDs,
+		usageID:    usageID,
+		endpointID: endpointID,
+		makeDriver: makeDriver,
+		quit:       make(chan chan error),
+	}
+	hub.refreshWallets()
+	return hub, nil
+}
+
+// Wallets implements accounts.Backend, returning all the currently tracked USB
+// devices that appear to be hardware wallets.
+func (hub *Hub) Wallets() []accounts.Wallet {
+	// Make sure the list of wallets is up to date
+	hub.refreshWallets()
+
+	hub.stateLock.RLock()
+	defer hub.stateLock.RUnlock()
+
+	cpy := make([]accounts.Wallet, len(hub.wallets))
+	copy(cpy, hub.wallets)
+	return cpy
+}
+
+// refreshWallets scans the USB devices attached to the machine and updates the
+// list of wallets based on the found devices.
+func (hub *Hub) refreshWallets() {
+	// Don't scan the USB like crazy it the user fetches wallets in a loop
+	hub.stateLock.RLock()
+	elapsed := time.Since(hub.refreshed)
+	hub.stateLock.RUnlock()
+
+	if elapsed < refreshThrottling {
+		return
+	}
+	// Retrieve the current list of USB wallet devices
+	var devices []hid.DeviceInfo
+
+	if runtime.GOOS == "linux" {
+		// hidapi on Linux opens the device during enumeration to retrieve some infos,
+		// breaking the Ledger protocol if that is waiting for user confirmation. This
+		// is a bug acknowledged at Ledger, but it won't be fixed on old devices so we
+		// need to prevent concurrent comms ourselves. The more elegant solution would
+		// be to ditch enumeration in favor of hotplug events, but that don't work yet
+		// on Windows so if we need to hack it anyway, this is more elegant for now.
+		hub.commsLock.Lock()
+		if hub.commsPend > 0 { // A confirmation is pending, don't refresh
+			hub.commsLock.Unlock()
+			return
+		}
+	}
+	for _, info := range hid.Enumerate(hub.vendorID, 0) {
+		for _, id := range hub.productIDs {
+			if info.ProductID == id && (info.UsagePage == hub.usageID || info.Interface == hub.endpointID) {
+				devices = append(devices, info)
+				break
+			}
+		}
+	}
+	if runtime.GOOS == "linux" {
+		// See rationale before the enumeration why this is needed and only on Linux.
+		hub.commsLock.Unlock()
+	}
+	// Transform the current list of wallets into the new one
+	hub.stateLock.Lock()
+
+	var (
+		wallets = make([]accounts.Wallet, 0, len(devices))
+		events  []accounts.WalletEvent
+	)
+
+	for _, device := range devices {
+		url := accounts.URL{Scheme: hub.scheme, Path: device.Path}
+
+		// Drop wallets in front of the next device or those that failed for some reason
+		for len(hub.wallets) > 0 {
+			// Abort if we're past the current device and found an operational one
+			_, failure := hub.wallets[0].Status()
+			if hub.wallets[0].URL().Cmp(url) >= 0 || failure == nil {
+				break
+			}
+			// Drop the stale and failed devices
+			events = append(events, accounts.WalletEvent{Wallet: hub.wallets[0], Kind: accounts.WalletDropped})
+			hub.wallets = hub.wallets[1:]
+		}
+		// If there are no more wallets or the device is before the next, wrap new wallet
+		if len(hub.wallets) == 0 || hub.wallets[0].URL().Cmp(url) > 0 {
+			logger := log.New("url", url)
+			wallet := &wallet{hub: hub, driver: hub.makeDriver(logger), url: &url, info: device, log: logger}
+
+			events = append(events, accounts.WalletEvent{Wallet: wallet, Kind: accounts.WalletArrived})
+			wallets = append(wallets, wallet)
+			continue
+		}
+		// If the device is the same as the first wallet, keep it
+		if hub.wallets[0].URL().Cmp(url) == 0 {
+			wallets = append(wallets, hub.wallets[0])
+			hub.wallets = hub.wallets[1:]
+			continue
+		}
+	}
+	// Drop any leftover wallets and set the new batch
+	for _, wallet := range hub.wallets {
+		events = append(events, accounts.WalletEvent{Wallet: wallet, Kind: accounts.WalletDropped})
+	}
+	hub.refreshed = time.Now()
+	hub.wallets = wallets
+	hub.stateLock.Unlock()
+
+	// Fire all wallet events and return
+	for _, event := range events {
+		hub.updateFeed.Send(event)
+	}
+}
+
+// Subscribe implements accounts.Backend, creating an async subscription to
+// receive notifications on the addition or removal of USB wallets.
+func (hub *Hub) Subscribe(sink chan<- accounts.WalletEvent) event.Subscription {
+	// We need the mutex to reliably start/stop the update loop
+	hub.stateLock.Lock()
+	defer hub.stateLock.Unlock()
+
+	// Subscribe the caller and track the subscriber count
+	sub := hub.updateScope.Track(hub.updateFeed.Subscribe(sink))
+
+	// Subscribers require an active notification loop, start it
+	if !hub.updating {
+		hub.updating = true
+		go hub.updater()
+	}
+	return sub
+}
+
+// updater is responsible for maintaining an up-to-date list of wallets managed
+// by the USB hub, and for firing wallet addition/removal events.
+func (hub *Hub) updater() {
+	for {
+		// TODO: Wait for a USB hotplug event (not supported yet) or a refresh timeout
+		// <-hub.changes
+		time.Sleep(refreshCycle)
+
+		// Run the wallet refresher
+		hub.refreshWallets()
+
+		// If all our subscribers left, stop the updater
+		hub.stateLock.Lock()
+		if hub.updateScope.Count() == 0 {
+			hub.updating = false
+			hub.stateLock.Unlock()
+			return
+		}
+		hub.stateLock.Unlock()
+	}
+}

accounts/usbwallet/ledger.go

@@ -0,0 +1,464 @@
+// Copyright 2017 The go-ethereum Authors
+// This file is part of the go-ethereum library.
+//
+// The go-ethereum library is free software: you can redistribute it and/or modify
+// it under the terms of the GNU Lesser General Public License as published by
+// the Free Software Foundation, either version 3 of the License, or
+// (at your option) any later version.
+//
+// The go-ethereum library is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+// GNU Lesser General Public License for more details.
+//
+// You should have received a copy of the GNU Lesser General Public License
+// along with the go-ethereum library. If not, see <http://www.gnu.org/licenses/>.
+
+// This file contains the implementation for interacting with the Ledger hardware
+// wallets. The wire protocol spec can be found in the Ledger Blue GitHub repo:
+// https://raw.githubusercontent.com/LedgerHQ/blue-app-eth/master/doc/ethapp.asc
+
+package usbwallet
+
+import (
+	"encoding/binary"
+	"encoding/hex"
+	"errors"
+	"fmt"
+	"io"
+	"math/big"
+
+	"github.com/ethereum/go-ethereum/accounts"
+	"github.com/ethereum/go-ethereum/common"
+	"github.com/ethereum/go-ethereum/common/hexutil"
+	"github.com/ethereum/go-ethereum/core/types"
+	"github.com/ethereum/go-ethereum/log"
+	"github.com/ethereum/go-ethereum/rlp"
+)
+
+// ledgerOpcode is an enumeration encoding the supported Ledger opcodes.
+type ledgerOpcode byte
+
+// ledgerParam1 is an enumeration encoding the supported Ledger parameters for
+// specific opcodes. The same parameter values may be reused between opcodes.
+type ledgerParam1 byte
+
+// ledgerParam2 is an enumeration encoding the supported Ledger parameters for
+// specific opcodes. The same parameter values may be reused between opcodes.
+type ledgerParam2 byte
+
+const (
+	ledgerOpRetrieveAddress  ledgerOpcode = 0x02 // Returns the public key and Ethereum address for a given BIP 32 path
+	ledgerOpSignTransaction  ledgerOpcode = 0x04 // Signs an Ethereum transaction after having the user validate the parameters
+	ledgerOpGetConfiguration ledgerOpcode = 0x06 // Returns specific wallet application configuration
+
+	ledgerP1DirectlyFetchAddress    ledgerParam1 = 0x00 // Return address directly from the wallet
+	ledgerP1InitTransactionData     ledgerParam1 = 0x00 // First transaction data block for signing
+	ledgerP1ContTransactionData     ledgerParam1 = 0x80 // Subsequent transaction data block for signing
+	ledgerP2DiscardAddressChainCode ledgerParam2 = 0x00 // Do not return the chain code along with the address
+)
+
+// errLedgerReplyInvalidHeader is the error message returned by a Ledger data exchange
+// if the device replies with a mismatching header. This usually means the device
+// is in browser mode.
+var errLedgerReplyInvalidHeader = errors.New("ledger: invalid reply header")
+
+// errLedgerInvalidVersionReply is the error message returned by a Ledger version retrieval
+// when a response does arrive, but it does not contain the expected data.
+var errLedgerInvalidVersionReply = errors.New("ledger: invalid version reply")
+
+// ledgerDriver implements the communication with a Ledger hardware wallet.
+type ledgerDriver struct {
+	device  io.ReadWriter // USB device connection to communicate through
+	version [3]byte       // Current version of the Ledger firmware (zero if app is offline)
+	browser bool          // Flag whether the Ledger is in browser mode (reply channel mismatch)
+	failure error         // Any failure that would make the device unusable
+	log     log.Logger    // Contextual logger to tag the ledger with its id
+}
+
+// newLedgerDriver creates a new instance of a Ledger USB protocol driver.
+func newLedgerDriver(logger log.Logger) driver {
+	return &ledgerDriver{
+		log: logger,
+	}
+}
+
+// Status implements usbwallet.driver, returning various states the Ledger can
+// currently be in.
+func (w *ledgerDriver) Status() (string, error) {
+	if w.failure != nil {
+		return fmt.Sprintf("Failed: %v", w.failure), w.failure
+	}
+	if w.browser {
+		return "Ethereum app in browser mode", w.failure
+	}
+	if w.offline() {
+		return "Ethereum app offline", w.failure
+	}
+	return fmt.Sprintf("Ethereum app v%d.%d.%d online", w.version[0], w.version[1], w.version[2]), w.failure
+}
+
+// offline returns whether the wallet and the Ethereum app is offline or not.
+//
+// The method assumes that the state lock is held!
+func (w *ledgerDriver) offline() bool {
+	return w.version == [3]byte{0, 0, 0}
+}
+
+// Open implements usbwallet.driver, attempting to initialize the connection to the
+// Ledger hardware wallet. The Ledger does not require a user passphrase, so that
+// parameter is silently discarded.
+func (w *ledgerDriver) Open(device io.ReadWriter, passphrase string) error {
+	w.device, w.failure = device, nil
+
+	_, err := w.ledgerDerive(accounts.DefaultBaseDerivationPath)
+	if err != nil {
+		// Ethereum app is not running or in browser mode, nothing more to do, return
+		if err == errLedgerReplyInvalidHeader {
+			w.browser = true
+		}
+		return nil
+	}
+	// Try to resolve the Ethereum app's version, will fail prior to v1.0.2
+	if w.version, err = w.ledgerVersion(); err != nil {
+		w.version = [3]byte{1, 0, 0} // Assume worst case, can't verify if v1.0.0 or v1.0.1
+	}
+	return nil
+}
+
+// Close implements usbwallet.driver, cleaning up and metadata maintained within
+// the Ledger driver.
+func (w *ledgerDriver) Close() error {
+	w.browser, w.version = false, [3]byte{}
+	return nil
+}
+
+// Heartbeat implements usbwallet.driver, performing a sanity check against the
+// Ledger to see if it's still online.
+func (w *ledgerDriver) Heartbeat() error {
+	if _, err := w.ledgerVersion(); err != nil && err != errLedgerInvalidVersionReply {
+		w.failure = err
+		return err
+	}
+	return nil
+}
+
+// Derive implements usbwallet.driver, sending a derivation request to the Ledger
+// and returning the Ethereum address located on that derivation path.
+func (w *ledgerDriver) Derive(path accounts.DerivationPath) (common.Address, error) {
+	return w.ledgerDerive(path)
+}
+
+// SignTx implements usbwallet.driver, sending the transaction to the Ledger and
+// waiting for the user to confirm or deny the transaction.
+//
+// Note, if the version of the Ethereum application running on the Ledger wallet is
+// too old to sign EIP-155 transactions, but such is requested nonetheless, an error
+// will be returned opposed to silently signing in Homestead mode.
+func (w *ledgerDriver) SignTx(path accounts.DerivationPath, tx *types.Transaction, chainID *big.Int) (common.Address, *types.Transaction, error) {
+	// If the Ethereum app doesn't run, abort
+	if w.offline() {
+		return common.Address{}, nil, accounts.ErrWalletClosed
+	}
+	// Ensure the wallet is capable of signing the given transaction
+	if chainID != nil && w.version[0] <= 1 && w.version[1] <= 0 && w.version[2] <= 2 {
+		return common.Address{}, nil, fmt.Errorf("Ledger v%d.%d.%d doesn't support signing this transaction, please update to v1.0.3 at least", w.version[0], w.version[1], w.version[2])
+	}
+	// All infos gathered and metadata checks out, request signing
+	return w.ledgerSign(path, tx, chainID)
+}
+
+// ledgerVersion retrieves the current version of the Ethereum wallet app running
+// on the Ledger wallet.
+//
+// The version retrieval protocol is defined as follows:
+//
+//   CLA | INS | P1 | P2 | Lc | Le
+//   ----+-----+----+----+----+---
+//    E0 | 06  | 00 | 00 | 00 | 04
+//
+// With no input data, and the output data being:
+//
+//   Description                                        | Length
+//   ---------------------------------------------------+--------
+//   Flags 01: arbitrary data signature enabled by user | 1 byte
+//   Application major version                          | 1 byte
+//   Application minor version                          | 1 byte
+//   Application patch version                          | 1 byte
+func (w *ledgerDriver) ledgerVersion() ([3]byte, error) {
+	// Send the request and wait for the response
+	reply, err := w.ledgerExchange(ledgerOpGetConfiguration, 0, 0, nil)
+	if err != nil {
+		return [3]byte{}, err
+	}
+	if len(reply) != 4 {
+		return [3]byte{}, errLedgerInvalidVersionReply
+	}
+	// Cache the version for future reference
+	var version [3]byte
+	copy(version[:], reply[1:])
+	return version, nil
+}
+
+// ledgerDerive retrieves the currently active Ethereum address from a Ledger
+// wallet at the specified derivation path.
+//
+// The address derivation protocol is defined as follows:
+//
+//   CLA | INS | P1 | P2 | Lc  | Le
+//   ----+-----+----+----+-----+---
+//    E0 | 02  | 00 return address
+//               01 display address and confirm before returning
+//                  | 00: do not return the chain code
+//                  | 01: return the chain code
+//                       | var | 00
+//
+// Where the input data is:
+//
+//   Description                                      | Length
+//   -------------------------------------------------+--------
+//   Number of BIP 32 derivations to perform (max 10) | 1 byte
+//   First derivation index (big endian)              | 4 bytes
+//   ...                                              | 4 bytes
+//   Last derivation index (big endian)               | 4 bytes
+//
+// And the output data is:
+//
+//   Description             | Length
+//   ------------------------+-------------------
+//   Public Key length       | 1 byte
+//   Uncompressed Public Key | arbitrary
+//   Ethereum address length | 1 byte
+//   Ethereum address        | 40 bytes hex ascii
+//   Chain code if requested | 32 bytes
+func (w *ledgerDriver) ledgerDerive(derivationPath []uint32) (common.Address, error) {
+	// Flatten the derivation path into the Ledger request
+	path := make([]byte, 1+4*len(derivationPath))
+	path[0] = byte(len(derivationPath))
+	for i, component := range derivationPath {
+		binary.BigEndian.PutUint32(path[1+4*i:], component)
+	}
+	// Send the request and wait for the response
+	reply, err := w.ledgerExchange(ledgerOpRetrieveAddress, ledgerP1DirectlyFetchAddress, ledgerP2DiscardAddressChainCode, path)
+	if err != nil {
+		return common.Address{}, err
+	}
+	// Discard the public key, we don't need that for now
+	if len(reply) < 1 || len(reply) < 1+int(reply[0]) {
+		return common.Address{}, errors.New("reply lacks public key entry")
+	}
+	reply = reply[1+int(reply[0]):]
+
+	// Extract the Ethereum hex address string
+	if len(reply) < 1 || len(reply) < 1+int(reply[0]) {
+		return common.Address{}, errors.New("reply lacks address entry")
+	}
+	hexstr := reply[1 : 1+int(reply[0])]
+
+	// Decode the hex sting into an Ethereum address and return
+	var address common.Address
+	if _, err = hex.Decode(address[:], hexstr); err != nil {
+		return common.Address{}, err
+	}
+	return address, nil
+}
+
+// ledgerSign sends the transaction to the Ledger wallet, and waits for the user
+// to confirm or deny the transaction.
+//
+// The transaction signing protocol is defined as follows:
+//
+//   CLA | INS | P1 | P2 | Lc  | Le
+//   ----+-----+----+----+-----+---
+//    E0 | 04  | 00: first transaction data block
+//               80: subsequent transaction data block
+//                  | 00 | variable | variable
+//
+// Where the input for the first transaction block (first 255 bytes) is:
+//
+//   Description                                      | Length
+//   -------------------------------------------------+----------
+//   Number of BIP 32 derivations to perform (max 10) | 1 byte
+//   First derivation index (big endian)              | 4 bytes
+//   ...                                              | 4 bytes
+//   Last derivation index (big endian)               | 4 bytes
+//   RLP transaction chunk                            | arbitrary
+//
+// And the input for subsequent transaction blocks (first 255 bytes) are:
+//
+//   Description           | Length
+//   ----------------------+----------
+//   RLP transaction chunk | arbitrary
+//
+// And the output data is:
+//
+//   Description | Length
+//   ------------+---------
+//   signature V | 1 byte
+//   signature R | 32 bytes
+//   signature S | 32 bytes
+func (w *ledgerDriver) ledgerSign(derivationPath []uint32, tx *types.Transaction, chainID *big.Int) (common.Address, *types.Transaction, error) {
+	// Flatten the derivation path into the Ledger request
+	path := make([]byte, 1+4*len(derivationPath))
+	path[0] = byte(len(derivationPath))
+	for i, component := range derivationPath {
+		binary.BigEndian.PutUint32(path[1+4*i:], component)
+	}
+	// Create the transaction RLP based on whether legacy or EIP155 signing was requested
+	var (
+		txrlp []byte
+		err   error
+	)
+	if chainID == nil {
+		if txrlp, err = rlp.EncodeToBytes([]interface{}{tx.Nonce(), tx.GasPrice(), tx.Gas(), tx.To(), tx.Value(), tx.Data()}); err != nil {
+			return common.Address{}, nil, err
+		}
+	} else {
+		if txrlp, err = rlp.EncodeToBytes([]interface{}{tx.Nonce(), tx.GasPrice(), tx.Gas(), tx.To(), tx.Value(), tx.Data(), chainID, big.NewInt(0), big.NewInt(0)}); err != nil {
+			return common.Address{}, nil, err
+		}
+	}
+	payload := append(path, txrlp...)
+
+	// Send the request and wait for the response
+	var (
+		op    = ledgerP1InitTransactionData
+		reply []byte
+	)
+	for len(payload) > 0 {
+		// Calculate the size of the next data chunk
+		chunk := 255
+		if chunk > len(payload) {
+			chunk = len(payload)
+		}
+		// Send the chunk over, ensuring it's processed correctly
+		reply, err = w.ledgerExchange(ledgerOpSignTransaction, op, 0, payload[:chunk])
+		if err != nil {
+			return common.Address{}, nil, err
+		}
+		// Shift the payload and ensure subsequent chunks are marked as such
+		payload = payload[chunk:]
+		op = ledgerP1ContTransactionData
+	}
+	// Extract the Ethereum signature and do a sanity validation
+	if len(reply) != 65 {
+		return common.Address{}, nil, errors.New("reply lacks signature")
+	}
+	signature := append(reply[1:], reply[0])
+
+	// Create the correct signer and signature transform based on the chain ID
+	var signer types.Signer
+	if chainID == nil {
+		signer = new(types.HomesteadSigner)
+	} else {
+		signer = types.NewEIP155Signer(chainID)
+		signature[64] -= byte(chainID.Uint64()*2 + 35)
+	}
+	signed, err := tx.WithSignature(signer, signature)
+	if err != nil {
+		return common.Address{}, nil, err
+	}
+	sender, err := types.Sender(signer, signed)
+	if err != nil {
+		return common.Address{}, nil, err
+	}
+	return sender, signed, nil
+}
+
+// ledgerExchange performs a data exchange with the Ledger wallet, sending it a
+// message and retrieving the response.
+//
+// The common transport header is defined as follows:
+//
+//  Description                           | Length
+//  --------------------------------------+----------
+//  Communication channel ID (big endian) | 2 bytes
+//  Command tag                           | 1 byte
+//  Packet sequence index (big endian)    | 2 bytes
+//  Payload                               | arbitrary
+//
+// The Communication channel ID allows commands multiplexing over the same
+// physical link. It is not used for the time being, and should be set to 0101
+// to avoid compatibility issues with implementations ignoring a leading 00 byte.
+//
+// The Command tag describes the message content. Use TAG_APDU (0x05) for standard
+// APDU payloads, or TAG_PING (0x02) for a simple link test.
+//
+// The Packet sequence index describes the current sequence for fragmented payloads.
+// The first fragment index is 0x00.
+//
+// APDU Command payloads are encoded as follows:
+//
+//  Description              | Length
+//  -----------------------------------
+//  APDU length (big endian) | 2 bytes
+//  APDU CLA                 | 1 byte
+//  APDU INS                 | 1 byte
+//  APDU P1                  | 1 byte
+//  APDU P2                  | 1 byte
+//  APDU length              | 1 byte
+//  Optional APDU data       | arbitrary
+func (w *ledgerDriver) ledgerExchange(opcode ledgerOpcode, p1 ledgerParam1, p2 ledgerParam2, data []byte) ([]byte, error) {
+	// Construct the message payload, possibly split into multiple chunks
+	apdu := make([]byte, 2, 7+len(data))
+
+	binary.BigEndian.PutUint16(apdu, uint16(5+len(data)))
+	apdu = append(apdu, []byte{0xe0, byte(opcode), byte(p1), byte(p2), byte(len(data))}...)
+	apdu = append(apdu, data...)
+
+	// Stream all the chunks to the device
+	header := []byte{0x01, 0x01, 0x05, 0x00, 0x00} // Channel ID and command tag appended
+	chunk := make([]byte, 64)
+	space := len(chunk) - len(header)
+
+	for i := 0; len(apdu) > 0; i++ {
+		// Construct the new message to stream
+		chunk = append(chunk[:0], header...)
+		binary.BigEndian.PutUint16(chunk[3:], uint16(i))
+
+		if len(apdu) > space {
+			chunk = append(chunk, apdu[:space]...)
+			apdu = apdu[space:]
+		} else {
+			chunk = append(chunk, apdu...)
+			apdu = nil
+		}
+		// Send over to the device
+		w.log.Trace("Data chunk sent to the Ledger", "chunk", hexutil.Bytes(chunk))
+		if _, err := w.device.Write(chunk); err != nil {
+			return nil, err
+		}
+	}
+	// Stream the reply back from the wallet in 64 byte chunks
+	var reply []byte
+	chunk = chunk[:64] // Yeah, we surely have enough space
+	for {
+		// Read the next chunk from the Ledger wallet
+		if _, err := io.ReadFull(w.device, chunk); err != nil {
+			return nil, err
+		}
+		w.log.Trace("Data chunk received from the Ledger", "chunk", hexutil.Bytes(chunk))
+
+		// Make sure the transport header matches
+		if chunk[0] != 0x01 || chunk[1] != 0x01 || chunk[2] != 0x05 {
+			return nil, errLedgerReplyInvalidHeader
+		}
+		// If it's the first chunk, retrieve the total message length
+		var payload []byte
+
+		if chunk[3] == 0x00 && chunk[4] == 0x00 {
+			reply = make([]byte, 0, int(binary.BigEndian.Uint16(chunk[5:7])))
+			payload = chunk[7:]
+		} else {
+			payload = chunk[5:]
+		}
+		// Append to the reply and stop when filled up
+		if left := cap(reply) - len(reply); left > len(payload) {
+			reply = append(reply, payload...)
+		} else {
+			reply = append(reply, payload[:left]...)
+			break
+		}
+	}
+	return reply[:len(reply)-2], nil
+}

accounts/usbwallet/trezor.go

@@ -0,0 +1,356 @@
+// Copyright 2017 The go-ethereum Authors
+// This file is part of the go-ethereum library.
+//
+// The go-ethereum library is free software: you can redistribute it and/or modify
+// it under the terms of the GNU Lesser General Public License as published by
+// the Free Software Foundation, either version 3 of the License, or
+// (at your option) any later version.
+//
+// The go-ethereum library is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+// GNU Lesser General Public License for more details.
+//
+// You should have received a copy of the GNU Lesser General Public License
+// along with the go-ethereum library. If not, see <http://www.gnu.org/licenses/>.
+
+// This file contains the implementation for interacting with the Trezor hardware
+// wallets. The wire protocol spec can be found on the SatoshiLabs website:
+// https://doc.satoshilabs.com/trezor-tech/api-protobuf.html
+
+package usbwallet
+
+import (
+	"encoding/binary"
+	"errors"
+	"fmt"
+	"io"
+	"math/big"
+
+	"github.com/ethereum/go-ethereum/accounts"
+	"github.com/ethereum/go-ethereum/accounts/usbwallet/trezor"
+	"github.com/ethereum/go-ethereum/common"
+	"github.com/ethereum/go-ethereum/common/hexutil"
+	"github.com/ethereum/go-ethereum/core/types"
+	"github.com/ethereum/go-ethereum/log"
+	"github.com/golang/protobuf/proto"
+)
+
+// ErrTrezorPINNeeded is returned if opening the trezor requires a PIN code. In
+// this case, the calling application should display a pinpad and send back the
+// encoded passphrase.
+var ErrTrezorPINNeeded = errors.New("trezor: pin needed")
+
+// ErrTrezorPassphraseNeeded is returned if opening the trezor requires a passphrase
+var ErrTrezorPassphraseNeeded = errors.New("trezor: passphrase needed")
+
+// errTrezorReplyInvalidHeader is the error message returned by a Trezor data exchange
+// if the device replies with a mismatching header. This usually means the device
+// is in browser mode.
+var errTrezorReplyInvalidHeader = errors.New("trezor: invalid reply header")
+
+// trezorDriver implements the communication with a Trezor hardware wallet.
+type trezorDriver struct {
+	device         io.ReadWriter // USB device connection to communicate through
+	version        [3]uint32     // Current version of the Trezor firmware
+	label          string        // Current textual label of the Trezor device
+	pinwait        bool          // Flags whether the device is waiting for PIN entry
+	passphrasewait bool          // Flags whether the device is waiting for passphrase entry
+	failure        error         // Any failure that would make the device unusable
+	log            log.Logger    // Contextual logger to tag the trezor with its id
+}
+
+// newTrezorDriver creates a new instance of a Trezor USB protocol driver.
+func newTrezorDriver(logger log.Logger) driver {
+	return &trezorDriver{
+		log: logger,
+	}
+}
+
+// Status implements accounts.Wallet, always whether the Trezor is opened, closed
+// or whether the Ethereum app was not started on it.
+func (w *trezorDriver) Status() (string, error) {
+	if w.failure != nil {
+		return fmt.Sprintf("Failed: %v", w.failure), w.failure
+	}
+	if w.device == nil {
+		return "Closed", w.failure
+	}
+	if w.pinwait {
+		return fmt.Sprintf("Trezor v%d.%d.%d '%s' waiting for PIN", w.version[0], w.version[1], w.version[2], w.label), w.failure
+	}
+	return fmt.Sprintf("Trezor v%d.%d.%d '%s' online", w.version[0], w.version[1], w.version[2], w.label), w.failure
+}
+
+// Open implements usbwallet.driver, attempting to initialize the connection to
+// the Trezor hardware wallet. Initializing the Trezor is a two or three phase operation:
+//  * The first phase is to initialize the connection and read the wallet's
+//    features. This phase is invoked if the provided passphrase is empty. The
+//    device will display the pinpad as a result and will return an appropriate
+//    error to notify the user that a second open phase is needed.
+//  * The second phase is to unlock access to the Trezor, which is done by the
+//    user actually providing a passphrase mapping a keyboard keypad to the pin
+//    number of the user (shuffled according to the pinpad displayed).
+//  * If needed the device will ask for passphrase which will require calling
+//    open again with the actual passphrase (3rd phase)
+func (w *trezorDriver) Open(device io.ReadWriter, passphrase string) error {
+	w.device, w.failure = device, nil
+
+	// If phase 1 is requested, init the connection and wait for user callback
+	if passphrase == "" && !w.passphrasewait {
+		// If we're already waiting for a PIN entry, insta-return
+		if w.pinwait {
+			return ErrTrezorPINNeeded
+		}
+		// Initialize a connection to the device
+		features := new(trezor.Features)
+		if _, err := w.trezorExchange(&trezor.Initialize{}, features); err != nil {
+			return err
+		}
+		w.version = [3]uint32{features.GetMajorVersion(), features.GetMinorVersion(), features.GetPatchVersion()}
+		w.label = features.GetLabel()
+
+		// Do a manual ping, forcing the device to ask for its PIN and Passphrase
+		askPin := true
+		askPassphrase := true
+		res, err := w.trezorExchange(&trezor.Ping{PinProtection: &askPin, PassphraseProtection: &askPassphrase}, new(trezor.PinMatrixRequest), new(trezor.PassphraseRequest), new(trezor.Success))
+		if err != nil {
+			return err
+		}
+		// Only return the PIN request if the device wasn't unlocked until now
+		switch res {
+		case 0:
+			w.pinwait = true
+			return ErrTrezorPINNeeded
+		case 1:
+			w.pinwait = false
+			w.passphrasewait = true
+			return ErrTrezorPassphraseNeeded
+		case 2:
+			return nil // responded with trezor.Success
+		}
+	}
+	// Phase 2 requested with actual PIN entry
+	if w.pinwait {
+		w.pinwait = false
+		res, err := w.trezorExchange(&trezor.PinMatrixAck{Pin: &passphrase}, new(trezor.Success), new(trezor.PassphraseRequest))
+		if err != nil {
+			w.failure = err
+			return err
+		}
+		if res == 1 {
+			w.passphrasewait = true
+			return ErrTrezorPassphraseNeeded
+		}
+	} else if w.passphrasewait {
+		w.passphrasewait = false
+		if _, err := w.trezorExchange(&trezor.PassphraseAck{Passphrase: &passphrase}, new(trezor.Success)); err != nil {
+			w.failure = err
+			return err
+		}
+	}
+
+	return nil
+}
+
+// Close implements usbwallet.driver, cleaning up and metadata maintained within
+// the Trezor driver.
+func (w *trezorDriver) Close() error {
+	w.version, w.label, w.pinwait = [3]uint32{}, "", false
+	return nil
+}
+
+// Heartbeat implements usbwallet.driver, performing a sanity check against the
+// Trezor to see if it's still online.
+func (w *trezorDriver) Heartbeat() error {
+	if _, err := w.trezorExchange(&trezor.Ping{}, new(trezor.Success)); err != nil {
+		w.failure = err
+		return err
+	}
+	return nil
+}
+
+// Derive implements usbwallet.driver, sending a derivation request to the Trezor
+// and returning the Ethereum address located on that derivation path.
+func (w *trezorDriver) Derive(path accounts.DerivationPath) (common.Address, error) {
+	return w.trezorDerive(path)
+}
+
+// SignTx implements usbwallet.driver, sending the transaction to the Trezor and
+// waiting for the user to confirm or deny the transaction.
+func (w *trezorDriver) SignTx(path accounts.DerivationPath, tx *types.Transaction, chainID *big.Int) (common.Address, *types.Transaction, error) {
+	if w.device == nil {
+		return common.Address{}, nil, accounts.ErrWalletClosed
+	}
+	return w.trezorSign(path, tx, chainID)
+}
+
+// trezorDerive sends a derivation request to the Trezor device and returns the
+// Ethereum address located on that path.
+func (w *trezorDriver) trezorDerive(derivationPath []uint32) (common.Address, error) {
+	address := new(trezor.EthereumAddress)
+	if _, err := w.trezorExchange(&trezor.EthereumGetAddress{AddressN: derivationPath}, address); err != nil {
+		return common.Address{}, err
+	}
+	return common.BytesToAddress(address.GetAddress()), nil
+}
+
+// trezorSign sends the transaction to the Trezor wallet, and waits for the user
+// to confirm or deny the transaction.
+func (w *trezorDriver) trezorSign(derivationPath []uint32, tx *types.Transaction, chainID *big.Int) (common.Address, *types.Transaction, error) {
+	// Create the transaction initiation message
+	data := tx.Data()
+	length := uint32(len(data))
+
+	request := &trezor.EthereumSignTx{
+		AddressN:   derivationPath,
+		Nonce:      new(big.Int).SetUint64(tx.Nonce()).Bytes(),
+		GasPrice:   tx.GasPrice().Bytes(),
+		GasLimit:   new(big.Int).SetUint64(tx.Gas()).Bytes(),
+		Value:      tx.Value().Bytes(),
+		DataLength: &length,
+	}
+	if to := tx.To(); to != nil {
+		request.To = (*to)[:] // Non contract deploy, set recipient explicitly
+	}
+	if length > 1024 { // Send the data chunked if that was requested
+		request.DataInitialChunk, data = data[:1024], data[1024:]
+	} else {
+		request.DataInitialChunk, data = data, nil
+	}
+	if chainID != nil { // EIP-155 transaction, set chain ID explicitly (only 32 bit is supported!?)
+		id := uint32(chainID.Int64())
+		request.ChainId = &id
+	}
+	// Send the initiation message and stream content until a signature is returned
+	response := new(trezor.EthereumTxRequest)
+	if _, err := w.trezorExchange(request, response); err != nil {
+		return common.Address{}, nil, err
+	}
+	for response.DataLength != nil && int(*response.DataLength) <= len(data) {
+		chunk := data[:*response.DataLength]
+		data = data[*response.DataLength:]
+
+		if _, err := w.trezorExchange(&trezor.EthereumTxAck{DataChunk: chunk}, response); err != nil {
+			return common.Address{}, nil, err
+		}
+	}
+	// Extract the Ethereum signature and do a sanity validation
+	if len(response.GetSignatureR()) == 0 || len(response.GetSignatureS()) == 0 || response.GetSignatureV() == 0 {
+		return common.Address{}, nil, errors.New("reply lacks signature")
+	}
+	signature := append(append(response.GetSignatureR(), response.GetSignatureS()...), byte(response.GetSignatureV()))
+
+	// Create the correct signer and signature transform based on the chain ID
+	var signer types.Signer
+	if chainID == nil {
+		signer = new(types.HomesteadSigner)
+	} else {
+		signer = types.NewEIP155Signer(chainID)
+		signature[64] -= byte(chainID.Uint64()*2 + 35)
+	}
+	// Inject the final signature into the transaction and sanity check the sender
+	signed, err := tx.WithSignature(signer, signature)
+	if err != nil {
+		return common.Address{}, nil, err
+	}
+	sender, err := types.Sender(signer, signed)
+	if err != nil {
+		return common.Address{}, nil, err
+	}
+	return sender, signed, nil
+}
+
+// trezorExchange performs a data exchange with the Trezor wallet, sending it a
+// message and retrieving the response. If multiple responses are possible, the
+// method will also return the index of the destination object used.
+func (w *trezorDriver) trezorExchange(req proto.Message, results ...proto.Message) (int, error) {
+	// Construct the original message payload to chunk up
+	data, err := proto.Marshal(req)
+	if err != nil {
+		return 0, err
+	}
+	payload := make([]byte, 8+len(data))
+	copy(payload, []byte{0x23, 0x23})
+	binary.BigEndian.PutUint16(payload[2:], trezor.Type(req))
+	binary.BigEndian.PutUint32(payload[4:], uint32(len(data)))
+	copy(payload[8:], data)
+
+	// Stream all the chunks to the device
+	chunk := make([]byte, 64)
+	chunk[0] = 0x3f // Report ID magic number
+
+	for len(payload) > 0 {
+		// Construct the new message to stream, padding with zeroes if needed
+		if len(payload) > 63 {
+			copy(chunk[1:], payload[:63])
+			payload = payload[63:]
+		} else {
+			copy(chunk[1:], payload)
+			copy(chunk[1+len(payload):], make([]byte, 63-len(payload)))
+			payload = nil
+		}
+		// Send over to the device
+		w.log.Trace("Data chunk sent to the Trezor", "chunk", hexutil.Bytes(chunk))
+		if _, err := w.device.Write(chunk); err != nil {
+			return 0, err
+		}
+	}
+	// Stream the reply back from the wallet in 64 byte chunks
+	var (
+		kind  uint16
+		reply []byte
+	)
+	for {
+		// Read the next chunk from the Trezor wallet
+		if _, err := io.ReadFull(w.device, chunk); err != nil {
+			return 0, err
+		}
+		w.log.Trace("Data chunk received from the Trezor", "chunk", hexutil.Bytes(chunk))
+
+		// Make sure the transport header matches
+		if chunk[0] != 0x3f || (len(reply) == 0 && (chunk[1] != 0x23 || chunk[2] != 0x23)) {
+			return 0, errTrezorReplyInvalidHeader
+		}
+		// If it's the first chunk, retrieve the reply message type and total message length
+		var payload []byte
+
+		if len(reply) == 0 {
+			kind = binary.BigEndian.Uint16(chunk[3:5])
+			reply = make([]byte, 0, int(binary.BigEndian.Uint32(chunk[5:9])))
+			payload = chunk[9:]
+		} else {
+			payload = chunk[1:]
+		}
+		// Append to the reply and stop when filled up
+		if left := cap(reply) - len(reply); left > len(payload) {
+			reply = append(reply, payload...)
+		} else {
+			reply = append(reply, payload[:left]...)
+			break
+		}
+	}
+	// Try to parse the reply into the requested reply message
+	if kind == uint16(trezor.MessageType_MessageType_Failure) {
+		// Trezor returned a failure, extract and return the message
+		failure := new(trezor.Failure)
+		if err := proto.Unmarshal(reply, failure); err != nil {
+			return 0, err
+		}
+		return 0, errors.New("trezor: " + failure.GetMessage())
+	}
+	if kind == uint16(trezor.MessageType_MessageType_ButtonRequest) {
+		// Trezor is waiting for user confirmation, ack and wait for the next message
+		return w.trezorExchange(&trezor.ButtonAck{}, results...)
+	}
+	for i, res := range results {
+		if trezor.Type(res) == kind {
+			return i, proto.Unmarshal(reply, res)
+		}
+	}
+	expected := make([]string, len(results))
+	for i, res := range results {
+		expected[i] = trezor.Name(trezor.Type(res))
+	}
+	return 0, fmt.Errorf("trezor: expected reply types %s, got %s", expected, trezor.Name(kind))
+}

accounts/usbwallet/trezor/messages.proto

@@ -0,0 +1,905 @@
+// This file originates from the SatoshiLabs Trezor `common` repository at:
+//   https://github.com/trezor/trezor-common/blob/master/protob/messages.proto
+// dated 28.07.2017, commit dd8ec3231fb5f7992360aff9bdfe30bb58130f4b.
+
+syntax = "proto2";
+
+/**
+ * Messages for TREZOR communication
+ */
+
+// Sugar for easier handling in Java
+option java_package = "com.satoshilabs.trezor.lib.protobuf";
+option java_outer_classname = "TrezorMessage";
+
+import "types.proto";
+
+/**
+ * Mapping between Trezor wire identifier (uint) and a protobuf message
+ */
+enum MessageType {
+	MessageType_Initialize = 0 [(wire_in) = true];
+	MessageType_Ping = 1 [(wire_in) = true];
+	MessageType_Success = 2 [(wire_out) = true];
+	MessageType_Failure = 3 [(wire_out) = true];
+	MessageType_ChangePin = 4 [(wire_in) = true];
+	MessageType_WipeDevice = 5 [(wire_in) = true];
+	MessageType_FirmwareErase = 6 [(wire_in) = true, (wire_bootloader) = true];
+	MessageType_FirmwareUpload = 7 [(wire_in) = true, (wire_bootloader) = true];
+	MessageType_FirmwareRequest = 8 [(wire_out) = true, (wire_bootloader) = true];
+	MessageType_GetEntropy = 9 [(wire_in) = true];
+	MessageType_Entropy = 10 [(wire_out) = true];
+	MessageType_GetPublicKey = 11 [(wire_in) = true];
+	MessageType_PublicKey = 12 [(wire_out) = true];
+	MessageType_LoadDevice = 13 [(wire_in) = true];
+	MessageType_ResetDevice = 14 [(wire_in) = true];
+	MessageType_SignTx = 15 [(wire_in) = true];
+	MessageType_SimpleSignTx = 16 [(wire_in) = true, deprecated = true];
+	MessageType_Features = 17 [(wire_out) = true];
+	MessageType_PinMatrixRequest = 18 [(wire_out) = true];
+	MessageType_PinMatrixAck = 19 [(wire_in) = true, (wire_tiny) = true];
+	MessageType_Cancel = 20 [(wire_in) = true];
+	MessageType_TxRequest = 21 [(wire_out) = true];
+	MessageType_TxAck = 22 [(wire_in) = true];
+	MessageType_CipherKeyValue = 23 [(wire_in) = true];
+	MessageType_ClearSession = 24 [(wire_in) = true];
+	MessageType_ApplySettings = 25 [(wire_in) = true];
+	MessageType_ButtonRequest = 26 [(wire_out) = true];
+	MessageType_ButtonAck = 27 [(wire_in) = true, (wire_tiny) = true];
+	MessageType_ApplyFlags = 28 [(wire_in) = true];
+	MessageType_GetAddress = 29 [(wire_in) = true];
+	MessageType_Address = 30 [(wire_out) = true];
+	MessageType_SelfTest = 32 [(wire_in) = true, (wire_bootloader) = true];
+	MessageType_BackupDevice = 34 [(wire_in) = true];
+	MessageType_EntropyRequest = 35 [(wire_out) = true];
+	MessageType_EntropyAck = 36 [(wire_in) = true];
+	MessageType_SignMessage = 38 [(wire_in) = true];
+	MessageType_VerifyMessage = 39 [(wire_in) = true];
+	MessageType_MessageSignature = 40 [(wire_out) = true];
+	MessageType_PassphraseRequest = 41 [(wire_out) = true];
+	MessageType_PassphraseAck = 42 [(wire_in) = true, (wire_tiny) = true];
+	MessageType_EstimateTxSize = 43 [(wire_in) = true, deprecated = true];
+	MessageType_TxSize = 44 [(wire_out) = true, deprecated = true];
+	MessageType_RecoveryDevice = 45 [(wire_in) = true];
+	MessageType_WordRequest = 46 [(wire_out) = true];
+	MessageType_WordAck = 47 [(wire_in) = true];
+	MessageType_CipheredKeyValue = 48 [(wire_out) = true];
+	MessageType_EncryptMessage = 49 [(wire_in) = true, deprecated = true];
+	MessageType_EncryptedMessage = 50 [(wire_out) = true, deprecated = true];
+	MessageType_DecryptMessage = 51 [(wire_in) = true, deprecated = true];
+	MessageType_DecryptedMessage = 52 [(wire_out) = true, deprecated = true];
+	MessageType_SignIdentity = 53 [(wire_in) = true];
+	MessageType_SignedIdentity = 54 [(wire_out) = true];
+	MessageType_GetFeatures = 55 [(wire_in) = true];
+	MessageType_EthereumGetAddress = 56 [(wire_in) = true];
+	MessageType_EthereumAddress = 57 [(wire_out) = true];
+	MessageType_EthereumSignTx = 58 [(wire_in) = true];
+	MessageType_EthereumTxRequest = 59 [(wire_out) = true];
+	MessageType_EthereumTxAck = 60 [(wire_in) = true];
+	MessageType_GetECDHSessionKey = 61 [(wire_in) = true];
+	MessageType_ECDHSessionKey = 62 [(wire_out) = true];
+	MessageType_SetU2FCounter = 63 [(wire_in) = true];
+	MessageType_EthereumSignMessage = 64 [(wire_in) = true];
+	MessageType_EthereumVerifyMessage = 65 [(wire_in) = true];
+	MessageType_EthereumMessageSignature = 66 [(wire_out) = true];
+	MessageType_DebugLinkDecision = 100 [(wire_debug_in) = true, (wire_tiny) = true];
+	MessageType_DebugLinkGetState = 101 [(wire_debug_in) = true];
+	MessageType_DebugLinkState = 102 [(wire_debug_out) = true];
+	MessageType_DebugLinkStop = 103 [(wire_debug_in) = true];
+	MessageType_DebugLinkLog = 104 [(wire_debug_out) = true];
+	MessageType_DebugLinkMemoryRead = 110 [(wire_debug_in) = true];
+	MessageType_DebugLinkMemory = 111 [(wire_debug_out) = true];
+	MessageType_DebugLinkMemoryWrite = 112 [(wire_debug_in) = true];
+	MessageType_DebugLinkFlashErase = 113 [(wire_debug_in) = true];
+}
+
+////////////////////
+// Basic messages //
+////////////////////
+
+/**
+ * Request: Reset device to default state and ask for device details
+ * @next Features
+ */
+message Initialize {
+}
+
+/**
+ * Request: Ask for device details (no device reset)
+ * @next Features
+ */
+message GetFeatures {
+}
+
+/**
+ * Response: Reports various information about the device
+ * @prev Initialize
+ * @prev GetFeatures
+ */
+message Features {
+	optional string vendor = 1;			// name of the manufacturer, e.g. "bitcointrezor.com"
+	optional uint32 major_version = 2;		// major version of the device, e.g. 1
+	optional uint32 minor_version = 3;		// minor version of the device, e.g. 0
+	optional uint32 patch_version = 4;		// patch version of the device, e.g. 0
+	optional bool bootloader_mode = 5;		// is device in bootloader mode?
+	optional string device_id = 6;			// device's unique identifier
+	optional bool pin_protection = 7;		// is device protected by PIN?
+	optional bool passphrase_protection = 8;	// is node/mnemonic encrypted using passphrase?
+	optional string language = 9;			// device language
+	optional string label = 10;			// device description label
+	repeated CoinType coins = 11;			// supported coins
+	optional bool initialized = 12;			// does device contain seed?
+	optional bytes revision = 13;			// SCM revision of firmware
+	optional bytes bootloader_hash = 14;		// hash of the bootloader
+	optional bool imported = 15;			// was storage imported from an external source?
+	optional bool pin_cached = 16;			// is PIN already cached in session?
+	optional bool passphrase_cached = 17;		// is passphrase already cached in session?
+	optional bool firmware_present = 18;		// is valid firmware loaded?
+	optional bool needs_backup = 19;		// does storage need backup? (equals to Storage.needs_backup)
+	optional uint32 flags = 20;			// device flags (equals to Storage.flags)
+}
+
+/**
+ * Request: clear session (removes cached PIN, passphrase, etc).
+ * @next Success
+ */
+message ClearSession {
+}
+
+/**
+ * Request: change language and/or label of the device
+ * @next Success
+ * @next Failure
+ * @next ButtonRequest
+ * @next PinMatrixRequest
+ */
+message ApplySettings {
+	optional string language = 1;
+	optional string label = 2;
+	optional bool use_passphrase = 3;
+	optional bytes homescreen = 4;
+}
+
+/**
+ * Request: set flags of the device
+ * @next Success
+ * @next Failure
+ */
+message ApplyFlags {
+	optional uint32 flags = 1;	// bitmask, can only set bits, not unset
+}
+
+/**
+ * Request: Starts workflow for setting/changing/removing the PIN
+ * @next ButtonRequest
+ * @next PinMatrixRequest
+ */
+message ChangePin {
+	optional bool remove = 1;	// is PIN removal requested?
+}
+
+/**
+ * Request: Test if the device is alive, device sends back the message in Success response
+ * @next Success
+ */
+message Ping {
+	optional string message = 1;			// message to send back in Success message
+	optional bool button_protection = 2;		// ask for button press
+	optional bool pin_protection = 3;		// ask for PIN if set in device
+	optional bool passphrase_protection = 4;	// ask for passphrase if set in device
+}
+
+/**
+ * Response: Success of the previous request
+ */
+message Success {
+	optional string message = 1;	// human readable description of action or request-specific payload
+}
+
+/**
+ * Response: Failure of the previous request
+ */
+message Failure {
+	optional FailureType code = 1;	// computer-readable definition of the error state
+	optional string message = 2;	// human-readable message of the error state
+}
+
+/**
+ * Response: Device is waiting for HW button press.
+ * @next ButtonAck
+ * @next Cancel
+ */
+message ButtonRequest {
+	optional ButtonRequestType code = 1;
+	optional string data = 2;
+}
+
+/**
+ * Request: Computer agrees to wait for HW button press
+ * @prev ButtonRequest
+ */
+message ButtonAck {
+}
+
+/**
+ * Response: Device is asking computer to show PIN matrix and awaits PIN encoded using this matrix scheme
+ * @next PinMatrixAck
+ * @next Cancel
+ */
+message PinMatrixRequest {
+	optional PinMatrixRequestType type = 1;
+}
+
+/**
+ * Request: Computer responds with encoded PIN
+ * @prev PinMatrixRequest
+ */
+message PinMatrixAck {
+	required string pin = 1;		// matrix encoded PIN entered by user
+}
+
+/**
+ * Request: Abort last operation that required user interaction
+ * @prev ButtonRequest
+ * @prev PinMatrixRequest
+ * @prev PassphraseRequest
+ */
+message Cancel {
+}
+
+/**
+ * Response: Device awaits encryption passphrase
+ * @next PassphraseAck
+ * @next Cancel
+ */
+message PassphraseRequest {
+}
+
+/**
+ * Request: Send passphrase back
+ * @prev PassphraseRequest
+ */
+message PassphraseAck {
+	required string passphrase = 1;
+}
+
+/**
+ * Request: Request a sample of random data generated by hardware RNG. May be used for testing.
+ * @next ButtonRequest
+ * @next Entropy
+ * @next Failure
+ */
+message GetEntropy {
+	required uint32 size = 1;		// size of requested entropy
+}
+
+/**
+ * Response: Reply with random data generated by internal RNG
+ * @prev GetEntropy
+ */
+message Entropy {
+	required bytes entropy = 1;		// stream of random generated bytes
+}
+
+/**
+ * Request: Ask device for public key corresponding to address_n path
+ * @next PassphraseRequest
+ * @next PublicKey
+ * @next Failure
+ */
+message GetPublicKey {
+	repeated uint32 address_n = 1;		// BIP-32 path to derive the key from master node
+	optional string ecdsa_curve_name = 2;	// ECDSA curve name to use
+	optional bool show_display = 3;		// optionally show on display before sending the result
+	optional string coin_name = 4 [default='Bitcoin'];
+}
+
+/**
+ * Response: Contains public key derived from device private seed
+ * @prev GetPublicKey
+ */
+message PublicKey {
+	required HDNodeType node = 1;		// BIP32 public node
+	optional string xpub = 2;		// serialized form of public node
+}
+
+/**
+ * Request: Ask device for address corresponding to address_n path
+ * @next PassphraseRequest
+ * @next Address
+ * @next Failure
+ */
+message GetAddress {
+	repeated uint32 address_n = 1;						// BIP-32 path to derive the key from master node
+	optional string coin_name = 2 [default='Bitcoin'];
+	optional bool show_display = 3			;			// optionally show on display before sending the result
+	optional MultisigRedeemScriptType multisig = 4;				// filled if we are showing a multisig address
+	optional InputScriptType script_type = 5 [default=SPENDADDRESS];	// used to distinguish between various address formats (non-segwit, segwit, etc.)
+}
+
+/**
+ * Request: Ask device for Ethereum address corresponding to address_n path
+ * @next PassphraseRequest
+ * @next EthereumAddress
+ * @next Failure
+ */
+message EthereumGetAddress {
+	repeated uint32 address_n = 1;			// BIP-32 path to derive the key from master node
+	optional bool show_display = 2;			// optionally show on display before sending the result
+}
+
+/**
+ * Response: Contains address derived from device private seed
+ * @prev GetAddress
+ */
+message Address {
+	required string address = 1;		// Coin address in Base58 encoding
+}
+
+/**
+ * Response: Contains an Ethereum address derived from device private seed
+ * @prev EthereumGetAddress
+ */
+message EthereumAddress {
+	required bytes address = 1;		// Coin address as an Ethereum 160 bit hash
+}
+
+/**
+ * Request: Request device to wipe all sensitive data and settings
+ * @next ButtonRequest
+ */
+message WipeDevice {
+}
+
+/**
+ * Request: Load seed and related internal settings from the computer
+ * @next ButtonRequest
+ * @next Success
+ * @next Failure
+ */
+message LoadDevice {
+	optional string mnemonic = 1;				// seed encoded as BIP-39 mnemonic (12, 18 or 24 words)
+	optional HDNodeType node = 2;				// BIP-32 node
+	optional string pin = 3;				// set PIN protection
+	optional bool passphrase_protection = 4;		// enable master node encryption using passphrase
+	optional string language = 5 [default='english'];	// device language
+	optional string label = 6;				// device label
+	optional bool skip_checksum = 7;			// do not test mnemonic for valid BIP-39 checksum
+	optional uint32 u2f_counter = 8;			// U2F counter
+}
+
+/**
+ * Request: Ask device to do initialization involving user interaction
+ * @next EntropyRequest
+ * @next Failure
+ */
+message ResetDevice {
+	optional bool display_random = 1;			// display entropy generated by the device before asking for additional entropy
+	optional uint32 strength = 2 [default=256];		// strength of seed in bits
+	optional bool passphrase_protection = 3;		// enable master node encryption using passphrase
+	optional bool pin_protection = 4;			// enable PIN protection
+	optional string language = 5 [default='english'];	// device language
+	optional string label = 6;				// device label
+	optional uint32 u2f_counter = 7;			// U2F counter
+	optional bool skip_backup = 8;				// postpone seed backup to BackupDevice workflow
+}
+
+/**
+ * Request: Perform backup of the device seed if not backed up using ResetDevice
+ * @next ButtonRequest
+ */
+message BackupDevice {
+}
+
+/**
+ * Response: Ask for additional entropy from host computer
+ * @prev ResetDevice
+ * @next EntropyAck
+ */
+message EntropyRequest {
+}
+
+/**
+ * Request: Provide additional entropy for seed generation function
+ * @prev EntropyRequest
+ * @next ButtonRequest
+ */
+message EntropyAck {
+	optional bytes entropy = 1;				// 256 bits (32 bytes) of random data
+}
+
+/**
+ * Request: Start recovery workflow asking user for specific words of mnemonic
+ * Used to recovery device safely even on untrusted computer.
+ * @next WordRequest
+ */
+message RecoveryDevice {
+	optional uint32 word_count = 1;				// number of words in BIP-39 mnemonic
+	optional bool passphrase_protection = 2;		// enable master node encryption using passphrase
+	optional bool pin_protection = 3;			// enable PIN protection
+	optional string language = 4 [default='english'];	// device language
+	optional string label = 5;				// device label
+	optional bool enforce_wordlist = 6;			// enforce BIP-39 wordlist during the process
+	// 7 reserved for unused recovery method
+	optional uint32 type = 8;				// supported recovery type (see RecoveryType)
+	optional uint32 u2f_counter = 9;			// U2F counter
+	optional bool dry_run = 10;				// perform dry-run recovery workflow (for safe mnemonic validation)
+}
+
+/**
+ * Response: Device is waiting for user to enter word of the mnemonic
+ * Its position is shown only on device's internal display.
+ * @prev RecoveryDevice
+ * @prev WordAck
+ */
+message WordRequest {
+	optional WordRequestType type = 1;
+}
+
+/**
+ * Request: Computer replies with word from the mnemonic
+ * @prev WordRequest
+ * @next WordRequest
+ * @next Success
+ * @next Failure
+ */
+message WordAck {
+	required string word = 1;				// one word of mnemonic on asked position
+}
+
+//////////////////////////////
+// Message signing messages //
+//////////////////////////////
+
+/**
+ * Request: Ask device to sign message
+ * @next MessageSignature
+ * @next Failure
+ */
+message SignMessage {
+	repeated uint32 address_n = 1;						// BIP-32 path to derive the key from master node
+	required bytes message = 2;						// message to be signed
+	optional string coin_name = 3 [default='Bitcoin'];			// coin to use for signing
+	optional InputScriptType script_type = 4 [default=SPENDADDRESS];	// used to distinguish between various address formats (non-segwit, segwit, etc.)
+}
+
+/**
+ * Request: Ask device to verify message
+ * @next Success
+ * @next Failure
+ */
+message VerifyMessage {
+	optional string address = 1;				// address to verify
+	optional bytes signature = 2;				// signature to verify
+	optional bytes message = 3;				// message to verify
+	optional string coin_name = 4 [default='Bitcoin'];	// coin to use for verifying
+}
+
+/**
+ * Response: Signed message
+ * @prev SignMessage
+ */
+message MessageSignature {
+	optional string address = 1;				// address used to sign the message
+	optional bytes signature = 2;				// signature of the message
+}
+
+///////////////////////////
+// Encryption/decryption //
+///////////////////////////
+
+/**
+ * Request: Ask device to encrypt message
+ * @next EncryptedMessage
+ * @next Failure
+ */
+message EncryptMessage {
+	optional bytes pubkey = 1;				// public key
+	optional bytes message = 2;				// message to encrypt
+	optional bool display_only = 3;				// show just on display? (don't send back via wire)
+	repeated uint32 address_n = 4;				// BIP-32 path to derive the signing key from master node
+	optional string coin_name = 5 [default='Bitcoin'];	// coin to use for signing
+}
+
+/**
+ * Response: Encrypted message
+ * @prev EncryptMessage
+ */
+message EncryptedMessage {
+	optional bytes nonce = 1;				// nonce used during encryption
+	optional bytes message = 2;				// encrypted message
+	optional bytes hmac = 3;				// message hmac
+}
+
+/**
+ * Request: Ask device to decrypt message
+ * @next Success
+ * @next Failure
+ */
+message DecryptMessage {
+	repeated uint32 address_n = 1;				// BIP-32 path to derive the decryption key from master node
+	optional bytes nonce = 2;				// nonce used during encryption
+	optional bytes message = 3;				// message to decrypt
+	optional bytes hmac = 4;				// message hmac
+}
+
+/**
+ * Response: Decrypted message
+ * @prev DecryptedMessage
+ */
+message DecryptedMessage {
+	optional bytes message = 1;				// decrypted message
+	optional string address = 2;				// address used to sign the message (if used)
+}
+
+/**
+ * Request: Ask device to encrypt or decrypt value of given key
+ * @next CipheredKeyValue
+ * @next Failure
+ */
+message CipherKeyValue {
+	repeated uint32 address_n = 1;		// BIP-32 path to derive the key from master node
+	optional string key = 2;		// key component of key:value
+	optional bytes value = 3;		// value component of key:value
+	optional bool encrypt = 4;		// are we encrypting (True) or decrypting (False)?
+	optional bool ask_on_encrypt = 5;	// should we ask on encrypt operation?
+	optional bool ask_on_decrypt = 6;	// should we ask on decrypt operation?
+	optional bytes iv = 7;			// initialization vector (will be computed if not set)
+}
+
+/**
+ * Response: Return ciphered/deciphered value
+ * @prev CipherKeyValue
+ */
+message CipheredKeyValue {
+	optional bytes value = 1;		// ciphered/deciphered value
+}
+
+//////////////////////////////////
+// Transaction signing messages //
+//////////////////////////////////
+
+/**
+ * Request: Estimated size of the transaction
+ * This behaves exactly like SignTx, which means that it can ask using TxRequest
+ * This call is non-blocking (except possible PassphraseRequest to unlock the seed)
+ * @next TxSize
+ * @next Failure
+ */
+message EstimateTxSize {
+	required uint32 outputs_count = 1;			// number of transaction outputs
+	required uint32 inputs_count = 2;			// number of transaction inputs
+	optional string coin_name = 3 [default='Bitcoin'];	// coin to use
+}
+
+/**
+ * Response: Estimated size of the transaction
+ * @prev EstimateTxSize
+ */
+message TxSize {
+	optional uint32 tx_size = 1;				// estimated size of transaction in bytes
+}
+
+/**
+ * Request: Ask device to sign transaction
+ * @next PassphraseRequest
+ * @next PinMatrixRequest
+ * @next TxRequest
+ * @next Failure
+ */
+message SignTx {
+	required uint32 outputs_count = 1;			// number of transaction outputs
+	required uint32 inputs_count = 2;			// number of transaction inputs
+	optional string coin_name = 3 [default='Bitcoin'];	// coin to use
+	optional uint32 version = 4 [default=1];		// transaction version
+	optional uint32 lock_time = 5 [default=0];		// transaction lock_time
+}
+
+/**
+ * Request: Simplified transaction signing
+ * This method doesn't support streaming, so there are hardware limits in number of inputs and outputs.
+ * In case of success, the result is returned using TxRequest message.
+ * @next PassphraseRequest
+ * @next PinMatrixRequest
+ * @next TxRequest
+ * @next Failure
+ */
+message SimpleSignTx {
+	repeated TxInputType inputs = 1;			// transaction inputs
+	repeated TxOutputType outputs = 2;			// transaction outputs
+	repeated TransactionType transactions = 3;		// transactions whose outputs are used to build current inputs
+	optional string coin_name = 4 [default='Bitcoin'];	// coin to use
+	optional uint32 version = 5 [default=1];		// transaction version
+	optional uint32 lock_time = 6 [default=0];		// transaction lock_time
+}
+
+/**
+ * Response: Device asks for information for signing transaction or returns the last result
+ * If request_index is set, device awaits TxAck message (with fields filled in according to request_type)
+ * If signature_index is set, 'signature' contains signed input of signature_index's input
+ * @prev SignTx
+ * @prev SimpleSignTx
+ * @prev TxAck
+ */
+message TxRequest {
+	optional RequestType request_type = 1;			// what should be filled in TxAck message?
+	optional TxRequestDetailsType details = 2;		// request for tx details
+	optional TxRequestSerializedType serialized = 3;	// serialized data and request for next
+}
+
+/**
+ * Request: Reported transaction data
+ * @prev TxRequest
+ * @next TxRequest
+ */
+message TxAck {
+	optional TransactionType tx = 1;
+}
+
+/**
+ * Request: Ask device to sign transaction
+ * All fields are optional from the protocol's point of view. Each field defaults to value `0` if missing.
+ * Note: the first at most 1024 bytes of data MUST be transmitted as part of this message.
+ * @next PassphraseRequest
+ * @next PinMatrixRequest
+ * @next EthereumTxRequest
+ * @next Failure
+ */
+message EthereumSignTx {
+	repeated uint32 address_n = 1;			// BIP-32 path to derive the key from master node
+	optional bytes nonce = 2;			// <=256 bit unsigned big endian
+	optional bytes gas_price = 3;			// <=256 bit unsigned big endian (in wei)
+	optional bytes gas_limit = 4;			// <=256 bit unsigned big endian
+	optional bytes to = 5;				// 160 bit address hash
+	optional bytes value = 6;			// <=256 bit unsigned big endian (in wei)
+	optional bytes data_initial_chunk = 7;		// The initial data chunk (<= 1024 bytes)
+	optional uint32 data_length = 8;		// Length of transaction payload
+	optional uint32 chain_id = 9;			// Chain Id for EIP 155
+}
+
+/**
+ * Response: Device asks for more data from transaction payload, or returns the signature.
+ * If data_length is set, device awaits that many more bytes of payload.
+ * Otherwise, the signature_* fields contain the computed transaction signature. All three fields will be present.
+ * @prev EthereumSignTx
+ * @next EthereumTxAck
+ */
+message EthereumTxRequest {
+	optional uint32 data_length = 1;		// Number of bytes being requested (<= 1024)
+	optional uint32 signature_v = 2;		// Computed signature (recovery parameter, limited to 27 or 28)
+	optional bytes signature_r = 3;			// Computed signature R component (256 bit)
+	optional bytes signature_s = 4;			// Computed signature S component (256 bit)
+}
+
+/**
+ * Request: Transaction payload data.
+ * @prev EthereumTxRequest
+ * @next EthereumTxRequest
+ */
+message EthereumTxAck {
+	optional bytes data_chunk = 1;			// Bytes from transaction payload (<= 1024 bytes)
+}
+
+////////////////////////////////////////
+// Ethereum: Message signing messages //
+////////////////////////////////////////
+
+/**
+ * Request: Ask device to sign message
+ * @next EthereumMessageSignature
+ * @next Failure
+ */
+message EthereumSignMessage {
+	repeated uint32 address_n = 1;				// BIP-32 path to derive the key from master node
+	required bytes message = 2;				// message to be signed
+}
+
+/**
+ * Request: Ask device to verify message
+ * @next Success
+ * @next Failure
+ */
+message EthereumVerifyMessage {
+	optional bytes address = 1;				// address to verify
+	optional bytes signature = 2;				// signature to verify
+	optional bytes message = 3;				// message to verify
+}
+
+/**
+ * Response: Signed message
+ * @prev EthereumSignMessage
+ */
+message EthereumMessageSignature {
+	optional bytes address = 1;				// address used to sign the message
+	optional bytes signature = 2;				// signature of the message
+}
+
+///////////////////////
+// Identity messages //
+///////////////////////
+
+/**
+ * Request: Ask device to sign identity
+ * @next SignedIdentity
+ * @next Failure
+ */
+message SignIdentity {
+	optional IdentityType identity = 1;		// identity
+	optional bytes challenge_hidden = 2;		// non-visible challenge
+	optional string challenge_visual = 3;		// challenge shown on display (e.g. date+time)
+	optional string ecdsa_curve_name = 4;		// ECDSA curve name to use
+}
+
+/**
+ * Response: Device provides signed identity
+ * @prev SignIdentity
+ */
+message SignedIdentity {
+	optional string address = 1;			// identity address
+	optional bytes public_key = 2;			// identity public key
+	optional bytes signature = 3;			// signature of the identity data
+}
+
+///////////////////
+// ECDH messages //
+///////////////////
+
+/**
+ * Request: Ask device to generate ECDH session key
+ * @next ECDHSessionKey
+ * @next Failure
+ */
+message GetECDHSessionKey {
+	optional IdentityType identity = 1;		// identity
+	optional bytes peer_public_key = 2;		// peer's public key
+	optional string ecdsa_curve_name = 3;		// ECDSA curve name to use
+}
+
+/**
+ * Response: Device provides ECDH session key
+ * @prev GetECDHSessionKey
+ */
+message ECDHSessionKey {
+	optional bytes session_key = 1;			// ECDH session key
+}
+
+///////////////////
+// U2F messages //
+///////////////////
+
+/**
+ * Request: Set U2F counter
+ * @next Success
+ */
+message SetU2FCounter {
+	optional uint32 u2f_counter = 1;		// counter
+}
+
+/////////////////////////
+// Bootloader messages //
+/////////////////////////
+
+/**
+ * Request: Ask device to erase its firmware (so it can be replaced via FirmwareUpload)
+ * @next Success
+ * @next FirmwareRequest
+ * @next Failure
+ */
+message FirmwareErase {
+	optional uint32 length = 1;			// length of new firmware
+}
+
+/**
+ * Response: Ask for firmware chunk
+ * @next FirmwareUpload
+ */
+message FirmwareRequest {
+	optional uint32 offset = 1;			// offset of requested firmware chunk
+	optional uint32 length = 2;			// length of requested firmware chunk
+}
+
+/**
+ * Request: Send firmware in binary form to the device
+ * @next Success
+ * @next Failure
+ */
+message FirmwareUpload {
+	required bytes payload = 1;			// firmware to be loaded into device
+	optional bytes hash = 2;			// hash of the payload
+}
+
+
+/**
+ * Request: Perform a device self-test
+ * @next Success
+ * @next Failure
+ */
+message SelfTest {
+	optional bytes payload = 1;			// payload to be used in self-test
+}
+
+/////////////////////////////////////////////////////////////
+// Debug messages (only available if DebugLink is enabled) //
+/////////////////////////////////////////////////////////////
+
+/**
+ * Request: "Press" the button on the device
+ * @next Success
+ */
+message DebugLinkDecision {
+	required bool yes_no = 1;			// true for "Confirm", false for "Cancel"
+}
+
+/**
+ * Request: Computer asks for device state
+ * @next DebugLinkState
+ */
+message DebugLinkGetState {
+}
+
+/**
+ * Response: Device current state
+ * @prev DebugLinkGetState
+ */
+message DebugLinkState {
+	optional bytes layout = 1;			// raw buffer of display
+	optional string pin = 2;			// current PIN, blank if PIN is not set/enabled
+	optional string matrix = 3;			// current PIN matrix
+	optional string mnemonic = 4;			// current BIP-39 mnemonic
+	optional HDNodeType node = 5;			// current BIP-32 node
+	optional bool passphrase_protection = 6;	// is node/mnemonic encrypted using passphrase?
+	optional string reset_word = 7;			// word on device display during ResetDevice workflow
+	optional bytes reset_entropy = 8;		// current entropy during ResetDevice workflow
+	optional string recovery_fake_word = 9;		// (fake) word on display during RecoveryDevice workflow
+	optional uint32 recovery_word_pos = 10;		// index of mnemonic word the device is expecting during RecoveryDevice workflow
+}
+
+/**
+ * Request: Ask device to restart
+ */
+message DebugLinkStop {
+}
+
+/**
+ * Response: Device wants host to log event
+ */
+message DebugLinkLog {
+	optional uint32 level = 1;
+	optional string bucket = 2;
+	optional string text = 3;
+}
+
+/**
+ * Request: Read memory from device
+ * @next DebugLinkMemory
+ */
+message DebugLinkMemoryRead {
+	optional uint32 address = 1;
+	optional uint32 length = 2;
+}
+
+/**
+ * Response: Device sends memory back
+ * @prev DebugLinkMemoryRead
+ */
+message DebugLinkMemory {
+	optional bytes memory = 1;
+}
+
+/**
+ * Request: Write memory to device.
+ * WARNING: Writing to the wrong location can irreparably break the device.
+ */
+message DebugLinkMemoryWrite {
+	optional uint32 address = 1;
+	optional bytes memory = 2;
+	optional bool flash = 3;
+}
+
+/**
+ * Request: Erase block of flash on device
+ * WARNING: Writing to the wrong location can irreparably break the device.
+ */
+message DebugLinkFlashErase {
+	optional uint32 sector = 1;
+}

accounts/usbwallet/trezor/trezor.go

@@ -0,0 +1,46 @@
+// Copyright 2017 The go-ethereum Authors
+// This file is part of the go-ethereum library.
+//
+// The go-ethereum library is free software: you can redistribute it and/or modify
+// it under the terms of the GNU Lesser General Public License as published by
+// the Free Software Foundation, either version 3 of the License, or
+// (at your option) any later version.
+//
+// The go-ethereum library is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+// GNU Lesser General Public License for more details.
+//
+// You should have received a copy of the GNU Lesser General Public License
+// along with the go-ethereum library. If not, see <http://www.gnu.org/licenses/>.
+
+// This file contains the implementation for interacting with the Trezor hardware
+// wallets. The wire protocol spec can be found on the SatoshiLabs website:
+// https://doc.satoshilabs.com/trezor-tech/api-protobuf.html
+
+//go:generate protoc --go_out=import_path=trezor:. types.proto messages.proto
+
+// Package trezor contains the wire protocol wrapper in Go.
+package trezor
+
+import (
+	"reflect"
+
+	"github.com/golang/protobuf/proto"
+)
+
+// Type returns the protocol buffer type number of a specific message. If the
+// message is nil, this method panics!
+func Type(msg proto.Message) uint16 {
+	return uint16(MessageType_value["MessageType_"+reflect.TypeOf(msg).Elem().Name()])
+}
+
+// Name returns the friendly message type name of a specific protocol buffer
+// type number.
+func Name(kind uint16) string {
+	name := MessageType_name[int32(kind)]
+	if len(name) < 12 {
+		return name
+	}
+	return name[12:]
+}

accounts/usbwallet/trezor/types.proto

@@ -0,0 +1,278 @@
+// This file originates from the SatoshiLabs Trezor `common` repository at:
+//   https://github.com/trezor/trezor-common/blob/master/protob/types.proto
+// dated 28.07.2017, commit dd8ec3231fb5f7992360aff9bdfe30bb58130f4b.
+
+syntax = "proto2";
+
+/**
+ * Types for TREZOR communication
+ *
+ * @author	Marek Palatinus <slush@satoshilabs.com>
+ * @version	1.2
+ */
+
+// Sugar for easier handling in Java
+option java_package = "com.satoshilabs.trezor.lib.protobuf";
+option java_outer_classname = "TrezorType";
+
+import "google/protobuf/descriptor.proto";
+
+/**
+ * Options for specifying message direction and type of wire (normal/debug)
+ */
+extend google.protobuf.EnumValueOptions {
+	optional bool wire_in = 50002;		// message can be transmitted via wire from PC to TREZOR
+	optional bool wire_out = 50003;		// message can be transmitted via wire from TREZOR to PC
+	optional bool wire_debug_in = 50004;	// message can be transmitted via debug wire from PC to TREZOR
+	optional bool wire_debug_out = 50005;	// message can be transmitted via debug wire from TREZOR to PC
+	optional bool wire_tiny = 50006;	// message is handled by TREZOR when the USB stack is in tiny mode
+	optional bool wire_bootloader = 50007;  // message is only handled by TREZOR Bootloader
+}
+
+/**
+ * Type of failures returned by Failure message
+ * @used_in Failure
+ */
+enum FailureType {
+	Failure_UnexpectedMessage = 1;
+	Failure_ButtonExpected = 2;
+	Failure_DataError = 3;
+	Failure_ActionCancelled = 4;
+	Failure_PinExpected = 5;
+	Failure_PinCancelled = 6;
+	Failure_PinInvalid = 7;
+	Failure_InvalidSignature = 8;
+	Failure_ProcessError = 9;
+	Failure_NotEnoughFunds = 10;
+	Failure_NotInitialized = 11;
+	Failure_FirmwareError = 99;
+}
+
+/**
+ * Type of script which will be used for transaction output
+ * @used_in TxOutputType
+ */
+enum OutputScriptType {
+	PAYTOADDRESS = 0;	// used for all addresses (bitcoin, p2sh, witness)
+	PAYTOSCRIPTHASH = 1;	// p2sh address (deprecated; use PAYTOADDRESS)
+	PAYTOMULTISIG = 2;	// only for change output
+	PAYTOOPRETURN = 3;	// op_return
+	PAYTOWITNESS = 4;	// only for change output
+	PAYTOP2SHWITNESS = 5;	// only for change output
+}
+
+/**
+ * Type of script which will be used for transaction output
+ * @used_in TxInputType
+ */
+enum InputScriptType {
+	SPENDADDRESS = 0;		// standard p2pkh address
+	SPENDMULTISIG = 1;		// p2sh multisig address
+	EXTERNAL = 2;			// reserved for external inputs (coinjoin)
+	SPENDWITNESS = 3;		// native segwit
+	SPENDP2SHWITNESS = 4;		// segwit over p2sh (backward compatible)
+}
+
+/**
+ * Type of information required by transaction signing process
+ * @used_in TxRequest
+ */
+enum RequestType {
+	TXINPUT = 0;
+	TXOUTPUT = 1;
+	TXMETA = 2;
+	TXFINISHED = 3;
+	TXEXTRADATA = 4;
+}
+
+/**
+ * Type of button request
+ * @used_in ButtonRequest
+ */
+enum ButtonRequestType {
+	ButtonRequest_Other = 1;
+	ButtonRequest_FeeOverThreshold = 2;
+	ButtonRequest_ConfirmOutput = 3;
+	ButtonRequest_ResetDevice = 4;
+	ButtonRequest_ConfirmWord = 5;
+	ButtonRequest_WipeDevice = 6;
+	ButtonRequest_ProtectCall = 7;
+	ButtonRequest_SignTx = 8;
+	ButtonRequest_FirmwareCheck = 9;
+	ButtonRequest_Address = 10;
+	ButtonRequest_PublicKey = 11;
+}
+
+/**
+ * Type of PIN request
+ * @used_in PinMatrixRequest
+ */
+enum PinMatrixRequestType {
+	PinMatrixRequestType_Current = 1;
+	PinMatrixRequestType_NewFirst = 2;
+	PinMatrixRequestType_NewSecond = 3;
+}
+
+/**
+ * Type of recovery procedure. These should be used as bitmask, e.g.,
+ * `RecoveryDeviceType_ScrambledWords | RecoveryDeviceType_Matrix`
+ * listing every method supported by the host computer.
+ *
+ * Note that ScrambledWords must be supported by every implementation
+ * for backward compatibility; there is no way to not support it.
+ *
+ * @used_in RecoveryDevice
+ */
+enum RecoveryDeviceType {
+	// use powers of two when extending this field
+	RecoveryDeviceType_ScrambledWords = 0;		// words in scrambled order
+	RecoveryDeviceType_Matrix = 1;				// matrix recovery type
+}
+
+/**
+ * Type of Recovery Word request
+ * @used_in WordRequest
+ */
+enum WordRequestType {
+	WordRequestType_Plain = 0;
+	WordRequestType_Matrix9 = 1;
+	WordRequestType_Matrix6 = 2;
+}
+
+/**
+ * Structure representing BIP32 (hierarchical deterministic) node
+ * Used for imports of private key into the device and exporting public key out of device
+ * @used_in PublicKey
+ * @used_in LoadDevice
+ * @used_in DebugLinkState
+ * @used_in Storage
+ */
+message HDNodeType {
+	required uint32 depth = 1;
+	required uint32 fingerprint = 2;
+	required uint32 child_num = 3;
+	required bytes chain_code = 4;
+	optional bytes private_key = 5;
+	optional bytes public_key = 6;
+}
+
+message HDNodePathType {
+	required HDNodeType node = 1;						// BIP-32 node in deserialized form
+	repeated uint32 address_n = 2;						// BIP-32 path to derive the key from node
+}
+
+/**
+ * Structure representing Coin
+ * @used_in Features
+ */
+message CoinType {
+	optional string coin_name = 1;
+	optional string coin_shortcut = 2;
+	optional uint32 address_type = 3 [default=0];
+	optional uint64 maxfee_kb = 4;
+	optional uint32 address_type_p2sh = 5 [default=5];
+	optional string signed_message_header = 8;
+	optional uint32 xpub_magic = 9 [default=76067358];	// default=0x0488b21e
+	optional uint32 xprv_magic = 10 [default=76066276];	// default=0x0488ade4
+	optional bool segwit = 11;
+	optional uint32 forkid = 12;
+}
+
+/**
+ * Type of redeem script used in input
+ * @used_in TxInputType
+ */
+message MultisigRedeemScriptType {
+	repeated HDNodePathType pubkeys = 1;					// pubkeys from multisig address (sorted lexicographically)
+	repeated bytes signatures = 2;						// existing signatures for partially signed input
+	optional uint32 m = 3;							// "m" from n, how many valid signatures is necessary for spending
+}
+
+/**
+ * Structure representing transaction input
+ * @used_in SimpleSignTx
+ * @used_in TransactionType
+ */
+message TxInputType {
+	repeated uint32 address_n = 1;						// BIP-32 path to derive the key from master node
+	required bytes prev_hash = 2;						// hash of previous transaction output to spend by this input
+	required uint32 prev_index = 3;						// index of previous output to spend
+	optional bytes script_sig = 4;						// script signature, unset for tx to sign
+	optional uint32 sequence = 5 [default=4294967295];			// sequence (default=0xffffffff)
+	optional InputScriptType script_type = 6 [default=SPENDADDRESS];	// defines template of input script
+	optional MultisigRedeemScriptType multisig = 7;				// Filled if input is going to spend multisig tx
+	optional uint64 amount = 8;						// amount of previous transaction output (for segwit only)
+}
+
+/**
+ * Structure representing transaction output
+ * @used_in SimpleSignTx
+ * @used_in TransactionType
+ */
+message TxOutputType {
+	optional string address = 1;			// target coin address in Base58 encoding
+	repeated uint32 address_n = 2;			// BIP-32 path to derive the key from master node; has higher priority than "address"
+	required uint64 amount = 3;			// amount to spend in satoshis
+	required OutputScriptType script_type = 4;	// output script type
+	optional MultisigRedeemScriptType multisig = 5; // defines multisig address; script_type must be PAYTOMULTISIG
+	optional bytes op_return_data = 6;		// defines op_return data; script_type must be PAYTOOPRETURN, amount must be 0
+}
+
+/**
+ * Structure representing compiled transaction output
+ * @used_in TransactionType
+ */
+message TxOutputBinType {
+	required uint64 amount = 1;
+	required bytes script_pubkey = 2;
+}
+
+/**
+ * Structure representing transaction
+ * @used_in SimpleSignTx
+ */
+message TransactionType {
+	optional uint32 version = 1;
+	repeated TxInputType inputs = 2;
+	repeated TxOutputBinType bin_outputs = 3;
+	repeated TxOutputType outputs = 5;
+	optional uint32 lock_time = 4;
+	optional uint32 inputs_cnt = 6;
+	optional uint32 outputs_cnt = 7;
+	optional bytes extra_data = 8;
+	optional uint32 extra_data_len = 9;
+}
+
+/**
+ * Structure representing request details
+ * @used_in TxRequest
+ */
+message TxRequestDetailsType {
+	optional uint32 request_index = 1;	// device expects TxAck message from the computer
+	optional bytes tx_hash = 2;		// tx_hash of requested transaction
+	optional uint32 extra_data_len = 3;	// length of requested extra data
+	optional uint32 extra_data_offset = 4;	// offset of requested extra data
+}
+
+/**
+ * Structure representing serialized data
+ * @used_in TxRequest
+ */
+message TxRequestSerializedType {
+	optional uint32 signature_index = 1;	// 'signature' field contains signed input of this index
+	optional bytes signature = 2;		// signature of the signature_index input
+	optional bytes serialized_tx = 3;	// part of serialized and signed transaction
+}
+
+/**
+ * Structure representing identity data
+ * @used_in IdentityType
+ */
+message IdentityType {
+	optional string proto = 1;			// proto part of URI
+	optional string user = 2;			// user part of URI
+	optional string host = 3;			// host part of URI
+	optional string port = 4;			// port part of URI
+	optional string path = 5;			// path part of URI
+	optional uint32 index = 6 [default=0];		// identity index
+}

accounts/usbwallet/wallet.go

@@ -0,0 +1,594 @@
+// Copyright 2017 The go-ethereum Authors
+// This file is part of the go-ethereum library.
+//
+// The go-ethereum library is free software: you can redistribute it and/or modify
+// it under the terms of the GNU Lesser General Public License as published by
+// the Free Software Foundation, either version 3 of the License, or
+// (at your option) any later version.
+//
+// The go-ethereum library is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+// GNU Lesser General Public License for more details.
+//
+// You should have received a copy of the GNU Lesser General Public License
+// along with the go-ethereum library. If not, see <http://www.gnu.org/licenses/>.
+
+// Package usbwallet implements support for USB hardware wallets.
+package usbwallet
+
+import (
+	"context"
+	"fmt"
+	"io"
+	"math/big"
+	"sync"
+	"time"
+
+	ethereum "github.com/ethereum/go-ethereum"
+	"github.com/ethereum/go-ethereum/accounts"
+	"github.com/ethereum/go-ethereum/common"
+	"github.com/ethereum/go-ethereum/core/types"
+	"github.com/ethereum/go-ethereum/crypto"
+	"github.com/ethereum/go-ethereum/log"
+	"github.com/karalabe/hid"
+)
+
+// Maximum time between wallet health checks to detect USB unplugs.
+const heartbeatCycle = time.Second
+
+// Minimum time to wait between self derivation attempts, even it the user is
+// requesting accounts like crazy.
+const selfDeriveThrottling = time.Second
+
+// driver defines the vendor specific functionality hardware wallets instances
+// must implement to allow using them with the wallet lifecycle management.
+type driver interface {
+	// Status returns a textual status to aid the user in the current state of the
+	// wallet. It also returns an error indicating any failure the wallet might have
+	// encountered.
+	Status() (string, error)
+
+	// Open initializes access to a wallet instance. The passphrase parameter may
+	// or may not be used by the implementation of a particular wallet instance.
+	Open(device io.ReadWriter, passphrase string) error
+
+	// Close releases any resources held by an open wallet instance.
+	Close() error
+
+	// Heartbeat performs a sanity check against the hardware wallet to see if it
+	// is still online and healthy.
+	Heartbeat() error
+
+	// Derive sends a derivation request to the USB device and returns the Ethereum
+	// address located on that path.
+	Derive(path accounts.DerivationPath) (common.Address, error)
+
+	// SignTx sends the transaction to the USB device and waits for the user to confirm
+	// or deny the transaction.
+	SignTx(path accounts.DerivationPath, tx *types.Transaction, chainID *big.Int) (common.Address, *types.Transaction, error)
+}
+
+// wallet represents the common functionality shared by all USB hardware
+// wallets to prevent reimplementing the same complex maintenance mechanisms
+// for different vendors.
+type wallet struct {
+	hub    *Hub          // USB hub scanning
+	driver driver        // Hardware implementation of the low level device operations
+	url    *accounts.URL // Textual URL uniquely identifying this wallet
+
+	info   hid.DeviceInfo // Known USB device infos about the wallet
+	device *hid.Device    // USB device advertising itself as a hardware wallet
+
+	accounts []accounts.Account                         // List of derive accounts pinned on the hardware wallet
+	paths    map[common.Address]accounts.DerivationPath // Known derivation paths for signing operations
+
+	deriveNextPaths []accounts.DerivationPath // Next derivation paths for account auto-discovery (multiple bases supported)
+	deriveNextAddrs []common.Address          // Next derived account addresses for auto-discovery (multiple bases supported)
+	deriveChain     ethereum.ChainStateReader // Blockchain state reader to discover used account with
+	deriveReq       chan chan struct{}        // Channel to request a self-derivation on
+	deriveQuit      chan chan error           // Channel to terminate the self-deriver with
+
+	healthQuit chan chan error
+
+	// Locking a hardware wallet is a bit special. Since hardware devices are lower
+	// performing, any communication with them might take a non negligible amount of
+	// time. Worse still, waiting for user confirmation can take arbitrarily long,
+	// but exclusive communication must be upheld during. Locking the entire wallet
+	// in the mean time however would stall any parts of the system that don't want
+	// to communicate, just read some state (e.g. list the accounts).
+	//
+	// As such, a hardware wallet needs two locks to function correctly. A state
+	// lock can be used to protect the wallet's software-side internal state, which
+	// must not be held exclusively during hardware communication. A communication
+	// lock can be used to achieve exclusive access to the device itself, this one
+	// however should allow "skipping" waiting for operations that might want to
+	// use the device, but can live without too (e.g. account self-derivation).
+	//
+	// Since we have two locks, it's important to know how to properly use them:
+	//   - Communication requires the `device` to not change, so obtaining the
+	//     commsLock should be done after having a stateLock.
+	//   - Communication must not disable read access to the wallet state, so it
+	//     must only ever hold a *read* lock to stateLock.
+	commsLock chan struct{} // Mutex (buf=1) for the USB comms without keeping the state locked
+	stateLock sync.RWMutex  // Protects read and write access to the wallet struct fields
+
+	log log.Logger // Contextual logger to tag the base with its id
+}
+
+// URL implements accounts.Wallet, returning the URL of the USB hardware device.
+func (w *wallet) URL() accounts.URL {
+	return *w.url // Immutable, no need for a lock
+}
+
+// Status implements accounts.Wallet, returning a custom status message from the
+// underlying vendor-specific hardware wallet implementation.
+func (w *wallet) Status() (string, error) {
+	w.stateLock.RLock() // No device communication, state lock is enough
+	defer w.stateLock.RUnlock()
+
+	status, failure := w.driver.Status()
+	if w.device == nil {
+		return "Closed", failure
+	}
+	return status, failure
+}
+
+// Open implements accounts.Wallet, attempting to open a USB connection to the
+// hardware wallet.
+func (w *wallet) Open(passphrase string) error {
+	w.stateLock.Lock() // State lock is enough since there's no connection yet at this point
+	defer w.stateLock.Unlock()
+
+	// If the device was already opened once, refuse to try again
+	if w.paths != nil {
+		return accounts.ErrWalletAlreadyOpen
+	}
+	// Make sure the actual device connection is done only once
+	if w.device == nil {
+		device, err := w.info.Open()
+		if err != nil {
+			return err
+		}
+		w.device = device
+		w.commsLock = make(chan struct{}, 1)
+		w.commsLock <- struct{}{} // Enable lock
+	}
+	// Delegate device initialization to the underlying driver
+	if err := w.driver.Open(w.device, passphrase); err != nil {
+		return err
+	}
+	// Connection successful, start life-cycle management
+	w.paths = make(map[common.Address]accounts.DerivationPath)
+
+	w.deriveReq = make(chan chan struct{})
+	w.deriveQuit = make(chan chan error)
+	w.healthQuit = make(chan chan error)
+
+	go w.heartbeat()
+	go w.selfDerive()
+
+	// Notify anyone listening for wallet events that a new device is accessible
+	go w.hub.updateFeed.Send(accounts.WalletEvent{Wallet: w, Kind: accounts.WalletOpened})
+
+	return nil
+}
+
+// heartbeat is a health check loop for the USB wallets to periodically verify
+// whether they are still present or if they malfunctioned.
+func (w *wallet) heartbeat() {
+	w.log.Debug("USB wallet health-check started")
+	defer w.log.Debug("USB wallet health-check stopped")
+
+	// Execute heartbeat checks until termination or error
+	var (
+		errc chan error
+		err  error
+	)
+	for errc == nil && err == nil {
+		// Wait until termination is requested or the heartbeat cycle arrives
+		select {
+		case errc = <-w.healthQuit:
+			// Termination requested
+			continue
+		case <-time.After(heartbeatCycle):
+			// Heartbeat time
+		}
+		// Execute a tiny data exchange to see responsiveness
+		w.stateLock.RLock()
+		if w.device == nil {
+			// Terminated while waiting for the lock
+			w.stateLock.RUnlock()
+			continue
+		}
+		<-w.commsLock // Don't lock state while resolving version
+		err = w.driver.Heartbeat()
+		w.commsLock <- struct{}{}
+		w.stateLock.RUnlock()
+
+		if err != nil {
+			w.stateLock.Lock() // Lock state to tear the wallet down
+			w.close()
+			w.stateLock.Unlock()
+		}
+		// Ignore non hardware related errors
+		err = nil
+	}
+	// In case of error, wait for termination
+	if err != nil {
+		w.log.Debug("USB wallet health-check failed", "err", err)
+		errc = <-w.healthQuit
+	}
+	errc <- err
+}
+
+// Close implements accounts.Wallet, closing the USB connection to the device.
+func (w *wallet) Close() error {
+	// Ensure the wallet was opened
+	w.stateLock.RLock()
+	hQuit, dQuit := w.healthQuit, w.deriveQuit
+	w.stateLock.RUnlock()
+
+	// Terminate the health checks
+	var herr error
+	if hQuit != nil {
+		errc := make(chan error)
+		hQuit <- errc
+		herr = <-errc // Save for later, we *must* close the USB
+	}
+	// Terminate the self-derivations
+	var derr error
+	if dQuit != nil {
+		errc := make(chan error)
+		dQuit <- errc
+		derr = <-errc // Save for later, we *must* close the USB
+	}
+	// Terminate the device connection
+	w.stateLock.Lock()
+	defer w.stateLock.Unlock()
+
+	w.healthQuit = nil
+	w.deriveQuit = nil
+	w.deriveReq = nil
+
+	if err := w.close(); err != nil {
+		return err
+	}
+	if herr != nil {
+		return herr
+	}
+	return derr
+}
+
+// close is the internal wallet closer that terminates the USB connection and
+// resets all the fields to their defaults.
+//
+// Note, close assumes the state lock is held!
+func (w *wallet) close() error {
+	// Allow duplicate closes, especially for health-check failures
+	if w.device == nil {
+		return nil
+	}
+	// Close the device, clear everything, then return
+	w.device.Close()
+	w.device = nil
+
+	w.accounts, w.paths = nil, nil
+	return w.driver.Close()
+}
+
+// Accounts implements accounts.Wallet, returning the list of accounts pinned to
+// the USB hardware wallet. If self-derivation was enabled, the account list is
+// periodically expanded based on current chain state.
+func (w *wallet) Accounts() []accounts.Account {
+	// Attempt self-derivation if it's running
+	reqc := make(chan struct{}, 1)
+	select {
+	case w.deriveReq <- reqc:
+		// Self-derivation request accepted, wait for it
+		<-reqc
+	default:
+		// Self-derivation offline, throttled or busy, skip
+	}
+	// Return whatever account list we ended up with
+	w.stateLock.RLock()
+	defer w.stateLock.RUnlock()
+
+	cpy := make([]accounts.Account, len(w.accounts))
+	copy(cpy, w.accounts)
+	return cpy
+}
+
+// selfDerive is an account derivation loop that upon request attempts to find
+// new non-zero accounts.
+func (w *wallet) selfDerive() {
+	w.log.Debug("USB wallet self-derivation started")
+	defer w.log.Debug("USB wallet self-derivation stopped")
+
+	// Execute self-derivations until termination or error
+	var (
+		reqc chan struct{}
+		errc chan error
+		err  error
+	)
+	for errc == nil && err == nil {
+		// Wait until either derivation or termination is requested
+		select {
+		case errc = <-w.deriveQuit:
+			// Termination requested
+			continue
+		case reqc = <-w.deriveReq:
+			// Account discovery requested
+		}
+		// Derivation needs a chain and device access, skip if either unavailable
+		w.stateLock.RLock()
+		if w.device == nil || w.deriveChain == nil {
+			w.stateLock.RUnlock()
+			reqc <- struct{}{}
+			continue
+		}
+		select {
+		case <-w.commsLock:
+		default:
+			w.stateLock.RUnlock()
+			reqc <- struct{}{}
+			continue
+		}
+		// Device lock obtained, derive the next batch of accounts
+		var (
+			accs  []accounts.Account
+			paths []accounts.DerivationPath
+
+			nextPaths = append([]accounts.DerivationPath{}, w.deriveNextPaths...)
+			nextAddrs = append([]common.Address{}, w.deriveNextAddrs...)
+
+			context = context.Background()
+		)
+		for i := 0; i < len(nextAddrs); i++ {
+			for empty := false; !empty; {
+				// Retrieve the next derived Ethereum account
+				if nextAddrs[i] == (common.Address{}) {
+					if nextAddrs[i], err = w.driver.Derive(nextPaths[i]); err != nil {
+						w.log.Warn("USB wallet account derivation failed", "err", err)
+						break
+					}
+				}
+				// Check the account's status against the current chain state
+				var (
+					balance *big.Int
+					nonce   uint64
+				)
+				balance, err = w.deriveChain.BalanceAt(context, nextAddrs[i], nil)
+				if err != nil {
+					w.log.Warn("USB wallet balance retrieval failed", "err", err)
+					break
+				}
+				nonce, err = w.deriveChain.NonceAt(context, nextAddrs[i], nil)
+				if err != nil {
+					w.log.Warn("USB wallet nonce retrieval failed", "err", err)
+					break
+				}
+				// If the next account is empty, stop self-derivation, but add for the last base path
+				if balance.Sign() == 0 && nonce == 0 {
+					empty = true
+					if i < len(nextAddrs)-1 {
+						break
+					}
+				}
+				// We've just self-derived a new account, start tracking it locally
+				path := make(accounts.DerivationPath, len(nextPaths[i]))
+				copy(path[:], nextPaths[i][:])
+				paths = append(paths, path)
+
+				account := accounts.Account{
+					Address: nextAddrs[i],
+					URL:     accounts.URL{Scheme: w.url.Scheme, Path: fmt.Sprintf("%s/%s", w.url.Path, path)},
+				}
+				accs = append(accs, account)
+
+				// Display a log message to the user for new (or previously empty accounts)
+				if _, known := w.paths[nextAddrs[i]]; !known || (!empty && nextAddrs[i] == w.deriveNextAddrs[i]) {
+					w.log.Info("USB wallet discovered new account", "address", nextAddrs[i], "path", path, "balance", balance, "nonce", nonce)
+				}
+				// Fetch the next potential account
+				if !empty {
+					nextAddrs[i] = common.Address{}
+					nextPaths[i][len(nextPaths[i])-1]++
+				}
+			}
+		}
+		// Self derivation complete, release device lock
+		w.commsLock <- struct{}{}
+		w.stateLock.RUnlock()
+
+		// Insert any accounts successfully derived
+		w.stateLock.Lock()
+		for i := 0; i < len(accs); i++ {
+			if _, ok := w.paths[accs[i].Address]; !ok {
+				w.accounts = append(w.accounts, accs[i])
+				w.paths[accs[i].Address] = paths[i]
+			}
+		}
+		// Shift the self-derivation forward
+		// TODO(karalabe): don't overwrite changes from wallet.SelfDerive
+		w.deriveNextAddrs = nextAddrs
+		w.deriveNextPaths = nextPaths
+		w.stateLock.Unlock()
+
+		// Notify the user of termination and loop after a bit of time (to avoid trashing)
+		reqc <- struct{}{}
+		if err == nil {
+			select {
+			case errc = <-w.deriveQuit:
+				// Termination requested, abort
+			case <-time.After(selfDeriveThrottling):
+				// Waited enough, willing to self-derive again
+			}
+		}
+	}
+	// In case of error, wait for termination
+	if err != nil {
+		w.log.Debug("USB wallet self-derivation failed", "err", err)
+		errc = <-w.deriveQuit
+	}
+	errc <- err
+}
+
+// Contains implements accounts.Wallet, returning whether a particular account is
+// or is not pinned into this wallet instance. Although we could attempt to resolve
+// unpinned accounts, that would be an non-negligible hardware operation.
+func (w *wallet) Contains(account accounts.Account) bool {
+	w.stateLock.RLock()
+	defer w.stateLock.RUnlock()
+
+	_, exists := w.paths[account.Address]
+	return exists
+}
+
+// Derive implements accounts.Wallet, deriving a new account at the specific
+// derivation path. If pin is set to true, the account will be added to the list
+// of tracked accounts.
+func (w *wallet) Derive(path accounts.DerivationPath, pin bool) (accounts.Account, error) {
+	// Try to derive the actual account and update its URL if successful
+	w.stateLock.RLock() // Avoid device disappearing during derivation
+
+	if w.device == nil {
+		w.stateLock.RUnlock()
+		return accounts.Account{}, accounts.ErrWalletClosed
+	}
+	<-w.commsLock // Avoid concurrent hardware access
+	address, err := w.driver.Derive(path)
+	w.commsLock <- struct{}{}
+
+	w.stateLock.RUnlock()
+
+	// If an error occurred or no pinning was requested, return
+	if err != nil {
+		return accounts.Account{}, err
+	}
+	account := accounts.Account{
+		Address: address,
+		URL:     accounts.URL{Scheme: w.url.Scheme, Path: fmt.Sprintf("%s/%s", w.url.Path, path)},
+	}
+	if !pin {
+		return account, nil
+	}
+	// Pinning needs to modify the state
+	w.stateLock.Lock()
+	defer w.stateLock.Unlock()
+
+	if _, ok := w.paths[address]; !ok {
+		w.accounts = append(w.accounts, account)
+		w.paths[address] = path
+	}
+	return account, nil
+}
+
+// SelfDerive sets a base account derivation path from which the wallet attempts
+// to discover non zero accounts and automatically add them to list of tracked
+// accounts.
+//
+// Note, self derivaton will increment the last component of the specified path
+// opposed to decending into a child path to allow discovering accounts starting
+// from non zero components.
+//
+// Some hardware wallets switched derivation paths through their evolution, so
+// this method supports providing multiple bases to discover old user accounts
+// too. Only the last base will be used to derive the next empty account.
+//
+// You can disable automatic account discovery by calling SelfDerive with a nil
+// chain state reader.
+func (w *wallet) SelfDerive(bases []accounts.DerivationPath, chain ethereum.ChainStateReader) {
+	w.stateLock.Lock()
+	defer w.stateLock.Unlock()
+
+	w.deriveNextPaths = make([]accounts.DerivationPath, len(bases))
+	for i, base := range bases {
+		w.deriveNextPaths[i] = make(accounts.DerivationPath, len(base))
+		copy(w.deriveNextPaths[i][:], base[:])
+	}
+	w.deriveNextAddrs = make([]common.Address, len(bases))
+	w.deriveChain = chain
+}
+
+// signHash implements accounts.Wallet, however signing arbitrary data is not
+// supported for hardware wallets, so this method will always return an error.
+func (w *wallet) signHash(account accounts.Account, hash []byte) ([]byte, error) {
+	return nil, accounts.ErrNotSupported
+}
+
+// SignData signs keccak256(data). The mimetype parameter describes the type of data being signed
+func (w *wallet) SignData(account accounts.Account, mimeType string, data []byte) ([]byte, error) {
+	return w.signHash(account, crypto.Keccak256(data))
+}
+
+// SignDataWithPassphrase implements accounts.Wallet, attempting to sign the given
+// data with the given account using passphrase as extra authentication.
+// Since USB wallets don't rely on passphrases, these are silently ignored.
+func (w *wallet) SignDataWithPassphrase(account accounts.Account, passphrase, mimeType string, data []byte) ([]byte, error) {
+	return w.SignData(account, mimeType, data)
+}
+
+func (w *wallet) SignText(account accounts.Account, text []byte) ([]byte, error) {
+	return w.signHash(account, accounts.TextHash(text))
+}
+
+// SignTx implements accounts.Wallet. It sends the transaction over to the Ledger
+// wallet to request a confirmation from the user. It returns either the signed
+// transaction or a failure if the user denied the transaction.
+//
+// Note, if the version of the Ethereum application running on the Ledger wallet is
+// too old to sign EIP-155 transactions, but such is requested nonetheless, an error
+// will be returned opposed to silently signing in Homestead mode.
+func (w *wallet) SignTx(account accounts.Account, tx *types.Transaction, chainID *big.Int) (*types.Transaction, error) {
+	w.stateLock.RLock() // Comms have own mutex, this is for the state fields
+	defer w.stateLock.RUnlock()
+
+	// If the wallet is closed, abort
+	if w.device == nil {
+		return nil, accounts.ErrWalletClosed
+	}
+	// Make sure the requested account is contained within
+	path, ok := w.paths[account.Address]
+	if !ok {
+		return nil, accounts.ErrUnknownAccount
+	}
+	// All infos gathered and metadata checks out, request signing
+	<-w.commsLock
+	defer func() { w.commsLock <- struct{}{} }()
+
+	// Ensure the device isn't screwed with while user confirmation is pending
+	// TODO(karalabe): remove if hotplug lands on Windows
+	w.hub.commsLock.Lock()
+	w.hub.commsPend++
+	w.hub.commsLock.Unlock()
+
+	defer func() {
+		w.hub.commsLock.Lock()
+		w.hub.commsPend--
+		w.hub.commsLock.Unlock()
+	}()
+	// Sign the transaction and verify the sender to avoid hardware fault surprises
+	sender, signed, err := w.driver.SignTx(path, tx, chainID)
+	if err != nil {
+		return nil, err
+	}
+	if sender != account.Address {
+		return nil, fmt.Errorf("signer mismatch: expected %s, got %s", account.Address.Hex(), sender.Hex())
+	}
+	return signed, nil
+}
+
+// SignHashWithPassphrase implements accounts.Wallet, however signing arbitrary
+// data is not supported for Ledger wallets, so this method will always return
+// an error.
+func (w *wallet) SignTextWithPassphrase(account accounts.Account, passphrase string, text []byte) ([]byte, error) {
+	return w.SignText(account, accounts.TextHash(text))
+}
+
+// SignTxWithPassphrase implements accounts.Wallet, attempting to sign the given
+// transaction with the given account using passphrase as extra authentication.
+// Since USB wallets don't rely on passphrases, these are silently ignored.
+func (w *wallet) SignTxWithPassphrase(account accounts.Account, passphrase string, tx *types.Transaction, chainID *big.Int) (*types.Transaction, error) {
+	return w.SignTx(account, tx, chainID)
+}