personal_sign fails to sign 32 byte hex payload in iOS

[SilentCicero]

When using personal_sign for Ethereum in iOS, TrustWallet states a different 20 byte payload from the 32 byte payload requested to sign. The resulting signature thus does not reduce to the "x19..." + len + hash below.

Try to run the example code below to reproduce.

const hash = '0x87b2d4b93731813f851f44e4a8e98e8e6e3680cc98081ea0c5c4ba4f6948c5a6';

// metamask/trust/coinbase if you have it
if (typeof window.web3 !== "undefined") {

  // enable eth
  window.ethereum.enable();

  // get accounts
  web3.currentProvider.sendAsync({ method: "eth_accounts", params: [] }, (err, accountResult) => {
    if (err) return console.error(err);

    const signerAddress = accountResult.result[0];

    web3.currentProvider.sendAsync({
      method: "personal_sign",
      params: [signerAddress, hash],
    }, (err, signerResult) => {
      // if (err) return console.error(err);
      console.log(signerResult);
    });
  });

}

[vikmeup]

Will look into this

[hewigovens]

@SilentCicero what's this hash?

const hash = '0x87b2d4b93731813f851f44e4a8e98e8e6e3680cc98081ea0c5c4ba4f6948c5a6';

from the doc, it should be data before UTF-8 HEX decoded. Trust will do following: envelope ethereum signed message prefix -> keccak256 -> sign

[hewigovens]

please check if this comment helps: https://github.com/TrustWallet/trust-wallet-ios/issues/947#issuecomment-453736156

[hewigovens]

Just tried metamask and Trust iOS, it works for me, note the first parameter is message to sign, not address. If you want to sign string, please wrap it with `web3.toHex("")

web3.currentProvider.sendAsync({
  method: "personal_sign",
  params: ["0x87b2d4b93731813f851f44e4a8e98e8e6e3680cc98081ea0c5c4ba4f6948c5a6", web3.eth.accounts[0]],
}, function(err, signerResult) {
  if (err) return console.error(err);
  console.log(signerResult);
});