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

A collection of useful crypto utilities for @polkadot

import { secp256k1 } from '@noble/curves/secp256k1';
import { hasBigInt, u8aToU8a } from '@polkadot/util';
import { isReady, secp256k1Recover as wasm } from '@polkadot/wasm-crypto';
import { secp256k1Compress } from './compress.js';
import { secp256k1Expand } from './expand.js';
/**
 * @name secp256k1Recover
 * @description Recovers a publicKey from the supplied signature
 */
export function secp256k1Recover(msgHash, signature, recovery, hashType = 'blake2', onlyJs) {
    const sig = u8aToU8a(signature).subarray(0, 64);
    const msg = u8aToU8a(msgHash);
    const publicKey = !hasBigInt || (!onlyJs && isReady())
        ? wasm(msg, sig, recovery)
        : secp256k1.Signature
            .fromCompact(sig)
            .addRecoveryBit(recovery)
            .recoverPublicKey(msg)
            .toRawBytes();
    if (!publicKey) {
        throw new Error('Unable to recover publicKey from signature');
    }
    return hashType === 'keccak'
        ? secp256k1Expand(publicKey, onlyJs)
        : secp256k1Compress(publicKey, onlyJs);
}