Verify Nonce Signature in the backend Golang

Question

I am trying to implement a metamask user authentication flow on BSC.

I managed to get it working on ethereum. The flow is like this.

I've found the code for ethereum on some gist however I am unable to do so for BSC and I am having a hard time understanding the documentation for BSC https://github.com/bnb-chain/bsc (same as go-ethereum). At least for the documentation I am used to this is so so unfriendly.

In order to verify the transaction I do this:

import("github.com/ethereum/go-ethereum/accounts"
"github.com/ethereum/go-ethereum/common/hexutil"
"github.com/ethereum/go-ethereum/crypto")

func verifySig(from, sigHex string, msg []byte) bool {
    sig := hexutil.MustDecode(sigHex)

    msg = accounts.TextHash(msg)
    sig[crypto.RecoveryIDOffset] -= 27 // Transform yellow paper V from 27/28 to 0/1

    recovered, err := crypto.SigToPub(msg, sig)
    if err != nil {
        return false
    }

    recoveredAddr := crypto.PubkeyToAddress(*recovered)

    return from == recoveredAddr.Hex()
}

I guess if I import the same things from https://github.com/bnb-chain/bsc and do the same thing it will work? Am I mistaken?

Answer 1

I just realized how stupid my question is.

Signing the message is just a cryptographic thing. The code above just checks that the incoming signature hex is valid using the nonce and message.

What I am doing doesn't involve anything regarding Ethereum or BSC, the same code will work on both without an issue.