从 go-ethereum 实现 Ethereum Personal_sign (EIP-191) 给出了与 ethers.js 不同的签名

Question

I am attempting to generate a personal_sign in Golang like its implemented in ethers.js. Similar question but that ended up using the regular sign over the personal sign_implementation .

Ethers

// keccak256 hash of the data
let dataHash = ethers.utils.keccak256(
  ethers.utils.toUtf8Bytes(JSON.stringify(dataToSign))
);

//0x8d218fc37d2fd952b2d115046b786b787e44d105cccf156882a2e74ad993ee13

let signature = await wallet.signMessage(dataHash); // 0x469b07327fc41a2d85b7e69bcf4a9184098835c47cc7575375e3a306c3718ae35702af84f3a62aafeb8aab6a455d761274263d79e7fc99fbedfeaf759d8dc9361c

Golang:

func signHash(data []byte) common.Hash {
    msg := fmt.Sprintf("\x19Ethereum Signed Message:\n%d%s", len(data), data)

    return crypto.Keccak256Hash([]byte(msg))
}

privateKey, err := crypto.HexToECDSA(hexPrivateKey)
if err != nil {
    log.Fatal(err)
}

dataHash := crypto.Keccak256Hash(dataToSign) //0x8d218fc37d2fd952b2d115046b786b787e44d105cccf156882a2e74ad993ee13

signHash := signHash(dataHash.Bytes())

signatureBytes, err := crypto.Sign(signHash.Bytes(), privateKey)
if err != nil {
    log.Fatal(err)
}


// signatureBytes 0xec56178d3dca77c3cee7aed83cdca2ffa2bec8ef1685ce5103cfa72c27beb61313d91b9ad9b9a644b0edf6352cb69f2f8acd25297e3c64cd060646242e0455ea00

As you can see the hash is the same, but the signature is different:

0x469b07327fc41a2d85b7e69bcf4a9184098835c47cc7575375e3a306c3718ae35702af84f3a62aafeb8aab6a455d761274263d79e7fc99fbedfeaf759d8dc9361c Ethers

0xec56178d3dca77c3cee7aed83cdca2ffa2bec8ef1685ce5103cfa72c27beb61313d91b9ad9b9a644b0edf6352cb69f2f8acd25297e3c64cd060646242e0455ea00 Golang

Looking at the source code of Ethers.js I can't find anything different aside how the padding is managed.

Edit Check the approved answer

signHash(data []byte) common.Hash {
    hexData := hexutil.Encode(data)
    msg := fmt.Sprintf("\x19Ethereum Signed Message:\n%d%s", len(hexData), hexData)

    return crypto.Keccak256Hash([]byte(msg))
}

Answer 1

There is a bug in the JavaScript code.

From the documentation of signer.signMessage() (see the Note section), it appears that a string is UTF8 encoded and binary data must be passed as TypedArray or Array .
The Keccak hash is returned hex encoded, ie as string, and is therefore UTF8 encoded, which is incorrect. Instead, it must be converted to a TypedArray . For this purpose the library provides the function ethers.utils.arrayify() .

The following JavaScript is based on the posted code, but performs the required hex decoding:

 (async () => { let privateKey = "0x8da4ef21b864d2cc526dbdb2a120bd2874c36c9d0a1fb7f8c63d7f7a8b41de8f"; let dataToSign = {"data1":"value1","data2":"value2"}; let dataHash = ethers.utils.keccak256( ethers.utils.toUtf8Bytes(JSON.stringify(dataToSign)) ); dataHashBin = ethers.utils.arrayify(dataHash) let wallet = new ethers.Wallet(privateKey); let signature = await wallet.signMessage(dataHashBin); document.getElementById("signature").innerHTML = signature; // 0xfcc3e9431c139b5f943591af78c280b939595ce9df66210b7b8bb69565bdd2af7081a8acc0cbb5ea55bd0d673b176797966a5180c11ac297b7e6344c5822e66d1c })();

 <script src="https://cdn.ethers.io/lib/ethers-5.0.umd.min.js" type="text/javascript"></script> <p style="font-family:'Courier New', monospace;" id="signature"></p>

which produces the following signature:

0xfcc3e9431c139b5f943591af78c280b939595ce9df66210b7b8bb69565bdd2af7081a8acc0cbb5ea55bd0d673b176797966a5180c11ac297b7e6344c5822e66d1c

---

The Go code below is based on the unmodified posted Go code, but using key and data from the JavaScript code for a comparison:

package main

import (
    "fmt"
    "github.com/ethereum/go-ethereum/common"
    "github.com/ethereum/go-ethereum/crypto"
    "encoding/hex"
    "encoding/json"
    "log"
)

func signHash(data []byte) common.Hash {
    msg := fmt.Sprintf("\x19Ethereum Signed Message:\n%d%s", len(data), data)
    return crypto.Keccak256Hash([]byte(msg))
}

func main() {

    hexPrivateKey := "8da4ef21b864d2cc526dbdb2a120bd2874c36c9d0a1fb7f8c63d7f7a8b41de8f"
    dataMap := map[string]string{"data1":"value1","data2":"value2"}
    dataToSign, _ := json.Marshal(dataMap)

    privateKey, err := crypto.HexToECDSA(hexPrivateKey)
    if err != nil {
            log.Fatal(err)
    }

    dataHash := crypto.Keccak256Hash(dataToSign) //0x8d218fc37d2fd952b2d115046b786b787e44d105cccf156882a2e74ad993ee13

    signHash := signHash(dataHash.Bytes())

    signatureBytes, err := crypto.Sign(signHash.Bytes(), privateKey)
    if err != nil {
            log.Fatal(err)
    }
    
    fmt.Println("0x" + hex.EncodeToString(signatureBytes))
}

The Go Code gives the following signature:

0xfcc3e9431c139b5f943591af78c280b939595ce9df66210b7b8bb69565bdd2af7081a8acc0cbb5ea55bd0d673b176797966a5180c11ac297b7e6344c5822e66d01

---

Both signatures match except for the last byte.

The JavaScript code returns the signature in the format r|s|v (see here ). v is one byte in size and is just the value in which both signatures differ.

It is v = 27 + rid where rid is the recovery ID. The recovery ID has values between 0 and 3, so v has values between 27 and 30 or 0x1b and 0x1e (see here ).

The Go code, on the other hand, returns the recovery ID in the last byte instead of v . So that the signature of the Go code matches that of the JavaScript code in the last byte as well, the recovery ID must be replaced by v :

signatureBytes[64] += 27
fmt.Println("0x" + hex.EncodeToString(signatureBytes))