How do I recover the address from message and signature generated with web3.personal.sign?

Question

Is there any way to do that? To recover address in nodejs server-side from signature and message after it was signed with web3.personal.sign client-side? I tried this: https://ethereum.stackexchange.com/a/12580/42452 with ethereumjs-util; I tried recoverTypedSignature() from eth-sig-util but in both cases recovered addresses didn't match signing addresses.

Here is the client-side code:

function authorize() {
  web3.eth.getAccounts(function (err, account) {
    let nonce = "123ABC";
    web3.personal.sign(nonce, account[0], function (err, signature) {
      //send to nodejs server
      $.post("http://localhost:8087", {signature: signature, nonce: nonce, address: account[0]}, function (data) {
        console.log(data);
      });
    })
  })
}

and server-side:

app.post('/', cors(corsOptions), function(req, res){
const msg = web3.sha3(nonce);
const sig = signature;
const {v, r, s} = util.fromRpcSig(sig);

const pubKey  = util.ecrecover(util.toBuffer(msg), v, r, s);
const addrBuf = util.pubToAddress(pubKey);
const addr    = util.bufferToHex(addrBuf);

console.log(addr);
});
app.listen(8087);

Answer 1

So, after many hours, I found a solution, that works. To make it works I used method from ethereumjs-util - ecrecover. I had to add some prefixed message to signed nonce. Code looks like this:

function checkSignature(nonce, signature, res) {

  nonce = "\x19Ethereum Signed Message:\n" + nonce.length + nonce;
  nonce = util.keccak(nonce);
  const sig = signature;
  const {v, r, s} = util.fromRpcSig(sig);
  const pubKey  = util.ecrecover(util.toBuffer(nonce), v, r, s);
  const addrBuf = util.pubToAddress(pubKey);
  const addr    = util.bufferToHex(addrBuf);
  console.log(addr);

}

Answer 2

Did you try web3's web3.eth.personal.ecRecover?

For example, if you sign via

web3.eth.personal.sign("Hello world", "0x11f4d0A3c12e86B4b5F39B213F7E19D048276DAe", "test password!")
.then(console.log);

> "0x30755ed65396facf86c53e6217c52b4daebe72aa4941d89635409de4c9c7f9466d4e9aaec7977f05e923889b33c0d0dd27d7226b6e6f56ce737465c5cfd04be400"

You "recover" via...

web3.eth.personal.ecRecover("Hello world", "0x30755ed65396facf86c53e6217c52b4daebe72aa4941d89635409de4c9c7f9466d4e9aaec7977f05e923889b33c0d0dd27d7226b6e6f56ce737465c5cfd04be400").then(console.log);

> "0x11f4d0A3c12e86B4b5F39B213F7E19D048276DAe"

Answer 3

Aug 2021

I achieve this by installing the npm package called eth-sig-util.

Here is my code:

const ethSigUtil = require("eth-sig-util");

function checkSignature(nonce, signature) {
    const msgParams = {
        data: nonce,
        sig: signature
    };
    return ethSigUtil.recoverPersonalSignature(msgParams);
}

Answer 4

2023 answer.

import { recoverAddress, getBytes, hashMessage } from "ethers";
const recoverPublicKey = (message, signature) => {
    const digest = getBytes(hashMessage(message));
    return recoverAddress(digest, signature);
}

It is copied from here: https://www.ethsigpublicaddress.com/ that I assume uses ethers js version 6.

Answer 5

Try this:

const recovered = web3.eth.accounts.recover("Some data"/*the unhashed message*/, "0xb3bd48482d2c13a1d1f3bba070fb9de9375ffc61347504fb4e3aed903fbc073e65588de1207ed716e0e439bfa527d44ea13a28ba08f79ac025a0e42b683967ec1b"/*the signature*/);
console.log("address: "+recovered);//address: 0x627306090abaB3A6e1400e9345bC60c78a8BEf57