From 4f9fd3da7e0191b294c6d3fb12b22048f1a7f873 Mon Sep 17 00:00:00 2001
From: frozen <355847+Frozen@users.noreply.github.com>
Date: Thu, 14 Mar 2024 11:40:25 -0400
Subject: [PATCH] verify

---
 core/vm/contracts.go                   | 93 +++++++++++++-------------
 core/vm/evm.go                         |  3 +
 crypto/groth16/{bn254 => bn256}/lib.go | 11 ++-
 internal/params/config.go              |  1 +
 4 files changed, 59 insertions(+), 49 deletions(-)
 rename crypto/groth16/{bn254 => bn256}/lib.go (60%)

diff --git a/core/vm/contracts.go b/core/vm/contracts.go
index f5c33eb03..df33698c5 100644
--- a/core/vm/contracts.go
+++ b/core/vm/contracts.go
@@ -22,11 +22,14 @@ import (
 	"encoding/binary"
 	//Needed for SHA3-256 FIPS202
 	"encoding/hex"
-	"errors"
 	"fmt"
+	"io"
 	"math/big"
 
+	"github.com/consensys/gnark/backend/groth16"
 	"github.com/ethereum/go-ethereum/crypto/blake2b"
+	groth16bn256 "github.com/harmony-one/harmony/crypto/groth16/bn256"
+	"github.com/pkg/errors"
 
 	"github.com/ethereum/go-ethereum/common"
 	"github.com/ethereum/go-ethereum/common/math"
@@ -38,8 +41,6 @@ import (
 	"golang.org/x/crypto/sha3"
 
 	"github.com/consensys/gnark-crypto/ecc"
-	"github.com/consensys/gnark-crypto/ecc/bn254/fr"
-	gnark "github.com/consensys/gnark/backend/groth16"
 	"github.com/consensys/gnark/backend/witness"
 	//gnarkLog "github.com/consensys/gnark/logger"
 )
@@ -171,83 +172,79 @@ func (g groth16Verify) RequiredGas(input []byte) uint64 {
 }
 
 func (g groth16Verify) Run(input []byte) ([]byte, error) {
-	//TODO implement me
-	panic("implement me")
+	buf := make([]byte, 2)
+	r := bytes.NewReader(input)
+	_, err := io.ReadFull(r, buf)
+	if err != nil {
+		return nil, errors.WithMessage(err, "failed to read first input")
+	}
+	s := binary.BigEndian.Uint16(buf)
+	verifyingKey := make([]byte, s)
+	_, err = io.ReadFull(r, verifyingKey)
+	if err != nil {
+		return nil, errors.WithMessagef(err, "failed to read data for first input of size %d", s)
+	}
+	_, err = io.ReadFull(r, buf)
+	if err != nil {
+		return nil, errors.WithMessage(err, "failed to read second input")
+	}
+	s = binary.BigEndian.Uint16(buf)
+	proof := make([]byte, s)
+	_, err = io.ReadFull(r, proof)
+	if err != nil {
+		return nil, errors.WithMessagef(err, "failed to read data for second input of size %d", s)
+	}
+	_, err = io.ReadFull(r, buf)
+	if err != nil {
+		return nil, errors.WithMessage(err, "failed to read third input")
+	}
+	s = binary.BigEndian.Uint16(buf)
+	inputs := make([]byte, s)
+	_, err = io.ReadFull(r, inputs)
+	if err != nil {
+		return nil, errors.WithMessagef(err, "failed to read data for third input of size %d", s)
+	}
+
+	Groth16Verify(verifyingKey, proof, inputs, ecc.BN254)
 }
 
 func Groth16Verify(verifyingKey []byte, proofBytes []byte, inputsBytes []byte, curve ecc.ID) (bool, error) {
 
-	var vk gnark.VerifyingKey
-	var proof gnark.Proof
+	var vk groth16.VerifyingKey
+	var proof groth16.Proof
 
 	switch curve {
 	case ecc.BN254:
-		bn256vk, err := FromBytesToVerifyingKey(verifyingKey)
+		bn256vk, err := groth16bn256.FromBytesToVerifyingKey(verifyingKey)
 		if err != nil {
 			return false, err
 		}
 		vk = bn256vk
 
-		bn256proof, err := bn256.FromBytesToProof(proofBytes)
+		bn256proof, err := groth16bn256.FromBytesToProof(proofBytes)
 		if err != nil {
 			return false, err
 		}
 		proof = bn256proof
 	default:
-		return false, errors.Errorf("unknown eliptic curve")
+		return false, errors.New("unknown eliptic curve")
 	}
 
-	var buf bytes.Buffer
-	buf.Grow(8 + 4 + len(inputsBytes))
-	// Add 8 bytes for correct reading
-	// Gnark witness has two addition number in the start
-	// These numbers aren't used for verification
-	buf.Write(make([]byte, 8))
-	err := binary.Write(&buf, binary.BigEndian, uint32(len(inputsBytes)/(fr.Limbs*sizeUint64)))
-	if err != nil {
-		return false, err
-	}
-	buf.Write(inputsBytes)
 	wit, err := witness.New(curve.ScalarField())
 	if err != nil {
 		return false, err
 	}
-	err = wit.UnmarshalBinary(buf.Bytes())
+	err = wit.UnmarshalBinary(inputsBytes)
 	if err != nil {
 		return false, err
 	}
-	err = gnark.Verify(proof, vk, wit)
+	err = groth16.Verify(proof, vk, wit)
 	if err != nil {
 		return false, nil
 	}
 	return true, nil
 }
 
-func FromBytesToProof(proofBytes []byte) (gnark.Proof, error) {
-	var bproof BellmanProofBn256
-	proofBytes, err := changeFlagsInProofToGnarkType(proofBytes)
-	if err != nil {
-		return nil, err
-	}
-	_, err = bproof.ReadFrom(bytes.NewReader(proofBytes))
-	if err != nil {
-		return nil, err
-	}
-
-	var b bytes.Buffer
-	_, err = bproof.WriteTo(&b)
-	if err != nil {
-		return nil, err
-	}
-
-	proof := gnark.NewProof(ecc.BN254)
-	_, err = proof.ReadFrom(bytes.NewReader(b.Bytes()))
-	if err != nil {
-		return nil, err
-	}
-	return proof, nil
-}
-
 func init() {
 	// check that there is no overlap, and panic if there is
 	readOnlyContracts := PrecompiledContractsStaking
diff --git a/core/vm/evm.go b/core/vm/evm.go
index 55f6f8c93..65437ece0 100644
--- a/core/vm/evm.go
+++ b/core/vm/evm.go
@@ -87,6 +87,9 @@ func run(evm *EVM, contract *Contract, input []byte, readOnly bool) ([]byte, err
 			precompiles = PrecompiledContractsStaking
 			writeCapablePrecompiles = WriteCapablePrecompiledContractsStaking
 		}
+		if evm.chainRules.IsGroth16Precompile {
+			precompiles = PrecompiledContractsGroth16
+		}
 		if evm.chainRules.IsCrossShardXferPrecompile {
 			writeCapablePrecompiles = WriteCapablePrecompiledContractsCrossXfer
 		}
diff --git a/crypto/groth16/bn254/lib.go b/crypto/groth16/bn256/lib.go
similarity index 60%
rename from crypto/groth16/bn254/lib.go
rename to crypto/groth16/bn256/lib.go
index f11cff356..6aa51855f 100644
--- a/crypto/groth16/bn254/lib.go
+++ b/crypto/groth16/bn256/lib.go
@@ -1,4 +1,4 @@
-package bn254
+package bn256
 
 import (
 	"bytes"
@@ -15,3 +15,12 @@ func FromBytesToVerifyingKey(verifyingKey []byte) (gnark.VerifyingKey, error) {
 	}
 	return vk, nil
 }
+
+func FromBytesToProof(proofBytes []byte) (gnark.Proof, error) {
+	proof := gnark.NewProof(ecc.BN254)
+	_, err := proof.ReadFrom(bytes.NewReader(proofBytes))
+	if err != nil {
+		return nil, err
+	}
+	return proof, nil
+}
diff --git a/internal/params/config.go b/internal/params/config.go
index 15ca7d287..becae8df2 100644
--- a/internal/params/config.go
+++ b/internal/params/config.go
@@ -879,6 +879,7 @@ type Rules struct {
 	// precompiles
 	IsIstanbul, IsVRF, IsPrevVRF, IsSHA3,
 	IsStakingPrecompile, IsCrossShardXferPrecompile,
+	IsGroth16Precompile,
 	// eip-155 chain id fix
 	IsChainIdFix bool
 	IsValidatorCodeFix bool