[Ethereum] Is the signature generated by “web3.personal.sign” different with “web3.eth.sign”

ecdsasignatureweb3js

Are web3.personal.sign and web3.eth.sign difference in value of generate signature ? Or both of them generate an equal output ?

I could test web3.eth.sign using testRPC, however web3.personal.sign with testRPC gives error and I could not compare the output of both method with the same input.

Best Answer

I think I had similar problem. I couldn't get correct address from ecrecover after message was signed with personal.sign, but it works fine after it was sign with eth.sign. Then I found this on web3 docs: https://web3js.readthedocs.io/en/1.0/web3-eth-personal.html#sign

"Signs data using a specific account. This data is before UTF-8 HEX decoded and enveloped as follows: "\x19Ethereum Signed Message:\n" + message.length + message."

After I added "\x19Ethereum Signed Message:\n" and message length to signed message, from which I want to recover address, it finally return correct address.

Related Solutions

Web3.js Signatures – Difference Between eth.sign() and eth.accounts.sign() in Web3.js

Likely web3.eth.accounts sign method is encoding the chainId as the parameter V while web3.eth.sign (an older implementation) is not. This was an update wrt to EIP 155. More info: (https://github.com/ethereum/EIPs/blob/master/EIPS/eip-155.md)

[Ethereum] “Updated :” How to see “output” of “web3.personal.sign” in “browser”? (“Method personal_sign not supported”)

The signature is sent to your callback, which is empty in the code you shared. This should work:

web3.personal.sign("0x" + message.toString("hex"), "0xF4D2B942c3baebef5B81F4B909904015166b238A", function(err, signature) {
  console.log(signature);
  // Be sure to make use of the signature only here.
  // It will not be defined until this callback is invoked.
});

As an aside, note that your current code does not use MetaMask.

Best Answer

Related Solutions

Web3.js Signatures – Difference Between eth.sign() and eth.accounts.sign() in Web3.js

[Ethereum] “Updated :” How to see “output” of “web3.personal.sign” in “browser”? (“Method personal_sign not supported”)

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