@polkadot/util-crypto/secp256k1/verify.js

A collection of useful crypto utilities for @polkadot

import { u8aEq, u8aToU8a } from '@polkadot/util';
import { hasher } from './hasher.js';
import { secp256k1Recover } from './recover.js';
/**
 * @name secp256k1Verify
 * @description Verifies the signature of `message`, using the supplied pair
 */
export function secp256k1Verify(msgHash, signature, address, hashType = 'blake2', onlyJs) {
    const sig = u8aToU8a(signature);
    if (sig.length !== 65) {
        throw new Error(`Expected signature with 65 bytes, ${sig.length} found instead`);
    }
    const publicKey = secp256k1Recover(hasher(hashType, msgHash), sig, sig[64], hashType, onlyJs);
    const signerAddr = hasher(hashType, publicKey, onlyJs);
    const inputAddr = u8aToU8a(address);
    // for Ethereum (keccak) the last 20 bytes is the address
    return u8aEq(publicKey, inputAddr) || (hashType === 'keccak'
        ? u8aEq(signerAddr.slice(-20), inputAddr.slice(-20))
        : u8aEq(signerAddr, inputAddr));
}