Address recovery broke in 2.2.0

[wbobeirne]

Hey there, I'm using eth-sig-util to do some signature validation on my backend. I recently redeployed the same code I had been using in a new project and found it was no longer working. This was because of an upgrade to eth-sig-util. I've gone ahead and created an example test that passes in 2.1.2, but fails in 2.2.0. I've narrowed it down to 0fbac01 as being the commit to break this. The signature and data blob here are from a real project using MetaMask v6.7.2 to do the signature.

test('broken recovery', (t) => {
  t.plan(1);
  const data = {
    "types": {
      "EIP712Domain": [
        {"name": "name", "type": "string"},
        {"name": "version", "type": "string"},
        {"name": "chainId", "type": "uint256"},
        {"name": "verifyingContract", "type": "string"}
      ],
      "authorization": [
        {"name": "userid", "type": "uint256"},
        {"name": "point", "type": "string"}
      ]
    },
    "domain": {
      "name": "test.test",
      "version": "1",
      "chainId": 1,
      "verifyingContract": "0x223c067f8cf28ae173ee5cafea60ca44c335fecb"
    },
    "primaryType": "authorization",
    "message": {
      "userid": 123,
      "point": "~hatteb-tondys"
    }
  };
  const sig = '0xab3b4a19d27b4f2ff9b2669888d1c3fee427b8c9ccabdeb91ef529a760aa593d00717dfa6f02d0ae0556f6c210ab5d5af41130d805d4659437d735172f7172c71c';
  const expectedAddress = '0x529104532a9779ea9Eae0C1e325b3368e0F8add4';

  const recoveredAddress = sigUtil.recoverTypedSignature({ data, sig });
  t.equal(expectedAddress.toLowerCase(), recoveredAddress.toLocaleLowerCase());
});

Is this because of verifyingContract being misinterpreted?

[wbobeirne]

OK, I can confirm that this works fine when I generate and recover a signature for the same data blob, minus verifyingContract. So it looks like MetaMask still has this issue when signing data with 0x in front, and it causes this library to recover it incorrectly. I'm guessing this wasn't caught because there are no tests for recoverTypedSignature.

[SwaroopH]

I ran into this while passing a string with 0x in the front.

@wbobeirne Great job on reproducing and getting to the bottom of the issue! Btw, in your case, verifyingContract should be defined as an address, right? Fortunately, that helped cause the issue, so all good :)

[janhesters]

Facing the same issue. When I try to recover a signature it fails with: Invalid signature length. Just as in OPs example, my signature is 132 characters, but in ethereumjs-util/dist/index.js.exports.fromRpcSig (index.js:438) the signature is expected to have 65 characters.

[jdowning100]

I have this issue too. Why is a signature generated by web3 considered invalid, signed by Metamask no less? Guess I'll use a different library.