parent
85633ef482
commit
c90d4fdcde
@ -1,21 +0,0 @@ |
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MIT License |
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|
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Copyright (c) 2018 Bas Westerbaan |
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Permission is hereby granted, free of charge, to any person obtaining a copy |
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of this software and associated documentation files (the "Software"), to deal |
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in the Software without restriction, including without limitation the rights |
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to use, copy, modify, merge, publish, distribute, sublicense, and/or sell |
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copies of the Software, and to permit persons to whom the Software is |
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furnished to do so, subject to the following conditions: |
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|
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The above copyright notice and this permission notice shall be included in all |
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copies or substantial portions of the Software. |
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|
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THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR |
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IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, |
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FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE |
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AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER |
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LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, |
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OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE |
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SOFTWARE. |
@ -1,57 +0,0 @@ |
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go-pow |
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====== |
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`go-pow` is a simple Go package to add (asymmetric) *Proof of Work* to your service. |
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To create a Proof-of-Work request (with difficulty 5), use `pow.NewRequest`: |
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```go |
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req := pow.NewRequest(5, someRandomNonce) |
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``` |
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This returns a string like `sha2bday-5-c29tZSByYW5kb20gbm9uY2U`, |
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which can be passed on to the client. |
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The client fulfils the proof of work by running `pow.Fulfil`: |
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```go |
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proof, _ := pow.Fulfil(req, []byte("some bound data")) |
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``` |
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The client returns the proof (in this case `AAAAAAAAAAMAAAAAAAAADgAAAAAAAAAb`) |
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to the server, which can check it is indeed a valid proof of work, by running: |
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``` go |
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ok, _ := pow.Check(req, proof, []byte("some bound data")) |
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``` |
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Notes |
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----- |
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1. There should be at least sufficient randomness in either the `nonce` passed to |
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`NewRequest` or the `data` passed to `Fulfil` and `Check`. |
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Thus it is fine to use the same bound `data` for every client, if every client |
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get a different `nonce` in its proof-of-work request. |
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It is also fine to use the same `nonce` in the proof-of-work request, |
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if every client is (by the encapsulating protocol) forced to use |
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different bound `data`. |
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2. The work to fulfil a request scales exponentially in the difficulty parameter. |
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The work to check it proof is correct remains constant: |
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|
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``` |
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Check on Difficulty=5 500000 2544 ns/op |
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Check on Difficulty=10 500000 2561 ns/op |
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Check on Difficulty=15 500000 2549 ns/op |
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Check on Difficulty=20 500000 2525 ns/op |
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Fulfil on Difficulty=5 100000 15725 ns/op |
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Fulfil on Difficulty=10 30000 46808 ns/op |
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Fulfil on Difficulty=15 2000 955606 ns/op |
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Fulfil on Difficulty=20 200 6887722 ns/op |
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``` |
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To do |
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----- |
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- Support for [equihash](https://www.cryptolux.org/index.php/Equihash) would be nice. |
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- Port to Python, Java, Javascript, ... |
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- Parallelize. |
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@ -1,128 +0,0 @@ |
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// Create and fulfill proof of work requests.
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package pow |
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import ( |
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"encoding/base64" |
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"fmt" |
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"strconv" |
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"strings" |
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) |
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type Algorithm string |
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const ( |
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Sha2BDay Algorithm = "sha2bday" |
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) |
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// Represents a proof-of-work request.
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type Request struct { |
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// The requested algorithm
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Alg Algorithm |
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// The requested difficulty
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Difficulty uint32 |
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// Nonce to diversify the request
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Nonce []byte |
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} |
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// Represents a completed proof-of-work
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type Proof struct { |
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buf []byte |
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} |
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// Convenience function to create a new sha3bday proof-of-work request
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// as a string
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func NewRequest(difficulty uint32, nonce []byte) string { |
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req := Request{ |
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Difficulty: difficulty, |
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Nonce: nonce, |
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Alg: Sha2BDay, |
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} |
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s, _ := req.MarshalText() |
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return string(s) |
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} |
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func (proof Proof) MarshalText() ([]byte, error) { |
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return []byte(base64.RawStdEncoding.EncodeToString(proof.buf)), nil |
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} |
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func (proof *Proof) UnmarshalText(buf []byte) error { |
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var err error |
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proof.buf, err = base64.RawStdEncoding.DecodeString(string(buf)) |
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return err |
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} |
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func (req Request) MarshalText() ([]byte, error) { |
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return []byte(fmt.Sprintf("%s-%d-%s", |
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req.Alg, |
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req.Difficulty, |
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string(base64.RawStdEncoding.EncodeToString(req.Nonce)))), nil |
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} |
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func (req *Request) UnmarshalText(buf []byte) error { |
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bits := strings.SplitN(string(buf), "-", 3) |
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if len(bits) != 3 { |
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return fmt.Errorf("There should be two dashes in a PoW request") |
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} |
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alg := Algorithm(bits[0]) |
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if alg != Sha2BDay { |
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return fmt.Errorf("%s: unsupported algorithm", bits[0]) |
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} |
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req.Alg = alg |
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diff, err := strconv.Atoi(bits[1]) |
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if err != nil { |
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return err |
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} |
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req.Difficulty = uint32(diff) |
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req.Nonce, err = base64.RawStdEncoding.DecodeString(bits[2]) |
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return err |
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} |
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// Convenience function to check whether a proof of work is fulfilled
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func Check(request, proof string, data []byte) (bool, error) { |
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var req Request |
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var prf Proof |
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err := req.UnmarshalText([]byte(request)) |
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if err != nil { |
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return false, err |
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} |
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err = prf.UnmarshalText([]byte(proof)) |
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if err != nil { |
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return false, err |
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} |
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return prf.Check(req, data), nil |
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} |
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// Fulfil the proof-of-work request.
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func (req *Request) Fulfil(data []byte) Proof { |
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switch req.Alg { |
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case Sha2BDay: |
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return Proof{fulfilSha2BDay(req.Nonce, req.Difficulty, data)} |
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default: |
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panic("No such algorithm") |
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} |
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} |
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// Convenience function to fulfil the proof of work request
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func Fulfil(request string, data []byte) (string, error) { |
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var req Request |
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err := req.UnmarshalText([]byte(request)) |
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if err != nil { |
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return "", err |
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} |
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proof := req.Fulfil(data) |
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s, _ := proof.MarshalText() |
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return string(s), nil |
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} |
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// Check whether the proof is ok
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func (proof *Proof) Check(req Request, data []byte) bool { |
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switch req.Alg { |
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case Sha2BDay: |
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return checkSha2BDay(proof.buf, req.Nonce, data, req.Difficulty) |
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default: |
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panic("No such algorithm") |
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} |
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} |
@ -1,56 +0,0 @@ |
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package pow |
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import ( |
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"testing" |
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) |
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func TestSha2BDay(t *testing.T) { |
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nonce := []byte{1, 2, 3, 4, 5} |
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data := []byte{2, 2, 3, 4, 5} |
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r := NewRequest(5, nonce) |
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proof, err := Fulfil(r, data) |
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if err != nil { |
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t.Fatalf("Fulfil: %v", err) |
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} |
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ok, err := Check(r, proof, data) |
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if err != nil { |
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t.Fatalf("Check: %v", err) |
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} |
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if !ok { |
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t.Fatalf("Proof of work should be ok") |
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} |
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ok, err = Check(r, proof, nonce) |
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if err != nil { |
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t.Fatalf("Check: %v", err) |
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} |
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if ok { |
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t.Fatalf("Proof of work should not be ok") |
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} |
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} |
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func BenchmarkCheck5(b *testing.B) { benchmarkCheck(5, b) } |
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func BenchmarkCheck10(b *testing.B) { benchmarkCheck(10, b) } |
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func BenchmarkCheck15(b *testing.B) { benchmarkCheck(15, b) } |
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func BenchmarkCheck20(b *testing.B) { benchmarkCheck(20, b) } |
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func benchmarkCheck(diff uint32, b *testing.B) { |
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req := NewRequest(diff, []byte{1, 2, 3, 4, 5}) |
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prf, _ := Fulfil(req, []byte{6, 7, 8, 9}) |
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b.ResetTimer() |
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for n := 0; n < b.N; n++ { |
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Check(req, prf, []byte{6, 7, 8, 9}) |
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} |
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} |
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func BenchmarkFulfil5(b *testing.B) { benchmarkFulfil(5, b) } |
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func BenchmarkFulfil10(b *testing.B) { benchmarkFulfil(10, b) } |
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func BenchmarkFulfil15(b *testing.B) { benchmarkFulfil(15, b) } |
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func BenchmarkFulfil20(b *testing.B) { benchmarkFulfil(20, b) } |
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func benchmarkFulfil(diff uint32, b *testing.B) { |
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req := NewRequest(diff, []byte{1, 2, 3, 4, 5}) |
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b.ResetTimer() |
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for n := 0; n < b.N; n++ { |
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Fulfil(req, []byte{6, 7, 8, 9}) |
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} |
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} |
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package pow_test |
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import ( |
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"fmt" // imported as pow
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"github.com/simple-rules/harmony-benchmark/pow" |
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) |
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func Example() { |
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// Create a proof of work request with difficulty 5
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req := pow.NewRequest(5, []byte("some random nonce")) |
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fmt.Printf("req: %s\n", req) |
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// Fulfil the proof of work
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proof, _ := pow.Fulfil(req, []byte("some bound data")) |
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fmt.Printf("proof: %s\n", proof) |
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// Check if the proof is correct
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ok, _ := pow.Check(req, proof, []byte("some bound data")) |
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fmt.Printf("check: %v", ok) |
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// Output: req: sha2bday-5-c29tZSByYW5kb20gbm9uY2U
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// proof: AAAAAAAAAAMAAAAAAAAADgAAAAAAAAAb
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// check: true
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} |
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package pow |
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import ( |
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"bytes" |
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"crypto/sha256" |
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"encoding/binary" |
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) |
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func checkSha2BDay(proof []byte, nonce, data []byte, diff uint32) bool { |
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if len(proof) != 24 { |
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return false |
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} |
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prefix1 := proof[:8] |
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prefix2 := proof[8:16] |
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prefix3 := proof[16:] |
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if bytes.Equal(prefix1, prefix2) || bytes.Equal(prefix2, prefix3) || |
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bytes.Equal(prefix1, prefix3) { |
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return false |
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} |
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resBuf := make([]byte, 32) |
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h := sha256.New() |
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h.Write(prefix1) |
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h.Write(data) |
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h.Write(nonce) |
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h.Sum(resBuf[:0]) |
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res1 := binary.BigEndian.Uint64(resBuf) & ((1 << diff) - 1) |
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h.Reset() |
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h.Write(prefix2) |
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h.Write(data) |
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h.Write(nonce) |
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h.Sum(resBuf[:0]) |
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res2 := binary.BigEndian.Uint64(resBuf) & ((1 << diff) - 1) |
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h.Reset() |
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h.Write(prefix3) |
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h.Write(data) |
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h.Write(nonce) |
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h.Sum(resBuf[:0]) |
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res3 := binary.BigEndian.Uint64(resBuf) & ((1 << diff) - 1) |
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return res1 == res2 && res2 == res3 |
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} |
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func fulfilSha2BDay(nonce []byte, diff uint32, data []byte) []byte { |
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// TODO make multithreaded if the difficulty is high enough.
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// For light proof-of-work requests, the overhead of parallelizing is
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// not worth it.
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type Pair struct { |
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First, Second uint64 |
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} |
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var i uint64 = 1 |
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prefix := make([]byte, 8) |
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resBuf := make([]byte, 32) |
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lut := make(map[uint64]Pair) |
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h := sha256.New() |
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for { |
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binary.BigEndian.PutUint64(prefix, i) |
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h.Write(prefix) |
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h.Write(data) |
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h.Write(nonce) |
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h.Sum(resBuf[:0]) |
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res := binary.BigEndian.Uint64(resBuf) & ((1 << diff) - 1) |
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pair, ok := lut[res] |
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if ok { |
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if pair.Second != 0 { |
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ret := make([]byte, 24) |
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binary.BigEndian.PutUint64(ret, pair.First) |
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binary.BigEndian.PutUint64(ret[8:], pair.Second) |
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copy(ret[16:], prefix) |
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return ret |
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} |
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lut[res] = Pair{First: pair.First, Second: i} |
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} else { |
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lut[res] = Pair{First: i} |
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} |
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h.Reset() |
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i++ |
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} |
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} |
Loading…
Reference in new issue