How to verify that a signature was signed by a pubkey? Taproot and BIP0322 - NTV News 🔥

Using wallets like XVerse, users can sign a message using their ordinal btc address, let's say bc1XXX, the message is hashed based on BIP0322.

So I have:

• User wallet: bc1XXX
• Message hash: YYY
• Signature signed by bc1XXX: ZZZ

So this data is sent to my backend server, and I want to verify that ZZZ was indeed signed by bc1XXX (and contains YYY as message).

I'm using this so far:

    const msgHash = bip0322Hash(message);
    const signatureBuffer = Buffer.from(signatureStr, 'base64');

    const decodedSignature = signatureBuffer.slice(2, 66);
    const recoveryId = signatureBuffer[0];

    // Extract public key from the signature
    const recoveredPublicKeyBuffer = secp.recoverPublicKey(
        msgHash,
        decodedSignature,
        recoveryId, // Recovery ID (0 or 1)
        false
    );
    console.log(publicKeyToTaprootAddress(recoveredPublicKeyBuffer)); //no match with my original pubkey that signed the message

But I have a hard time getting the correct address from recoveredPublicKeyBuffer which I can't match with the public key address of my test set.

I'm trying to use this function, but the output doesn't match my pubkey:

    function publicKeyToTaprootAddress(publicKey: Uint8Array) {
        // Compute the SHA-256 hash of the public key
        const hash = sha256(Buffer.from(publicKey));

        // Construct the human-readable part and the data part of the Bech32m string
        const hrp = 'bc';
        const data = sha256(Buffer.from([0x01].concat(Array.from(hash))));
        const data2 = bech32m.toWords(Buffer.from(data));

        // Encode the Bech32m string
        return bech32m.encode(hrp, data2);
    } 

from Recent Questions - Bitcoin Stack Exchange
May 18, 2023 at 12:33AM