2

I'm using ethers v6 and foundry to test message signing. Though having the same hashed message and the signer private key, I can't find out why the signature is different. The following is my script.

  • forge 0.2.0
  • ethers 6.9.0

solidity

function run() public {
        vm.startBroadcast();

        console.log("sender", vm.addr(senderPk));

        bytes32 message = keccak256(abi.encodePacked(uint256(42), false));

        console.log("message:");
        console.logBytes32(message);

        (uint8 v, bytes32 r, bytes32 s) = vm.sign(senderPk, message);
        bytes memory signature = abi.encodePacked(r, s, v);

        console.log("signature:");
        console.logBytes(signature);

        console.log("v", v);
        console.logBytes32(r);
        console.logBytes32(s);

        vm.stopBroadcast();
    }
== Logs ==
  sender 0xd58B38a32881Dc2a89aB2359b55Ad5Cd8aB621E4
  message:
  0x8c3e5593f2ccfe5fc2e6b9d1350aed0ff196ac3b543cd85b1d721562a7e46696
  signature:
  0xa375c84e232e704537ecad5d2f7b60472a8f7bcb7b8288e58c8467b0cec16f6049bbda12c780bd26fa2929902465fe804beadf9df3e7410658d3891cb1a49a011c
  v 28
  0xa375c84e232e704537ecad5d2f7b60472a8f7bcb7b8288e58c8467b0cec16f60
  0x49bbda12c780bd26fa2929902465fe804beadf9df3e7410658d3891cb1a49a01
  chainId 421614
  =================
  recovered signer 0xd58B38a32881Dc2a89aB2359b55Ad5Cd8aB621E4

typescript

const sender = new Wallet(process.env.DEV_PRIVATE_KEY).connect(provider)

console.log('sender:', sender.address)

const message = ethers.solidityPackedKeccak256(['uint256', 'bool'], [42n, false])

console.log('message: ', message)

const signature = await sender.signMessage(message)
console.log('signature: ', signature)
const sig = Signature.from(signature)

console.log('v:', sig.v)
console.log('r:', sig.r)
console.log('s:', sig.s)
chainId: 421614
sender: 0xd58B38a32881Dc2a89aB2359b55Ad5Cd8aB621E4
message:  0x8c3e5593f2ccfe5fc2e6b9d1350aed0ff196ac3b543cd85b1d721562a7e46696
signature:  0xb97111f21d2900395f74a9b6d3cce613e89c34cf5c37ec627a3f423d8d9af0c20159e62d82bdc9647fed4369e1eb96f881e77c35fb5f60bf81521b7922fba1721c
v: 28
r: 0xb97111f21d2900395f74a9b6d3cce613e89c34cf5c37ec627a3f423d8d9af0c2
s: 0x0159e62d82bdc9647fed4369e1eb96f881e77c35fb5f60bf81521b7922fba172
signer: 0xd58B38a32881Dc2a89aB2359b55Ad5Cd8aB621E4
1
  • Try this while calculating the message hash in foundry bytes32 message = keccak256("\x19\x01",abi.encodePacked(uint256(42), false)); Jan 13 at 13:25

1 Answer 1

3

I discovered that the signMessage function in ethers v6 follows EIP-191 , utilizing the string "\x19Ethereum Signed Message: + length of the message + message". For instance, if the message is "hello world", it gets signed as keccak256("\x19Ethereum Signed Message:\n11hello world")

In foundry, vm.sign(senderPk, message) is employed for signing a raw message. However, in ethers, there is no way to sign raw message due to security considerations. Refer to https://github.com/ethers-io/ethers.js/issues/555#issuecomment-508847309 for more details.

To achieve the same signature in Solidity, the approach is as follows:

bytes memory m = bytes("hello world");

bytes memory message = abi.encodePacked("\x19Ethereum Signed Message:\n", Strings.toString(m.length), m);

(uint8 v, bytes32 r, bytes32 s) = vm.sign(senderPk, keccak256(message));

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