antelope-ecc/sign.js

A universal JavaScript ECC digital signature and key utility package for Antelope based blockchains.

import binary_to_base58 from "base58-js/binary_to_base58.js";
import sign_secp256k1 from "isomorphic-secp256k1-js/sign.js";
import ripemd160 from "ripemd160-js/ripemd160.js";
import wif_to_private_key from "./keys/private_key_from_wif.js";
/**
 * Generate an Antelope K1 signature for a given hash and wif_private_key
 */
export default async function sign({ hash, wif_private_key, }) {
    const private_key = wif_to_private_key(wif_private_key);
    let hash_array;
    // Handle the case where hash is a string
    if (typeof hash === "string") {
        const hashMatches = hash.match(/[a-fA-F0-9]{2}/gmu);
        if (hashMatches)
            hash_array = Uint8Array.from(hashMatches.map((i) => Number(`0x${i}`)));
        else
            throw new Error("Invalid hash format.");
    }
    else if (hash instanceof Uint8Array)
        hash_array = hash;
    else
        throw new Error("Hash must be a string or a Uint8Array.");
    const { r, s, v } = await sign_secp256k1({ hash: hash_array, private_key });
    const i = 31 + Number(v); // compressed (4) + compact key(27).
    const K1 = [75, 49]; // K1 as ascii
    const raw_sig = [i, ...r, ...s];
    const ripe_hash = await ripemd160(Uint8Array.from([...raw_sig, ...K1]));
    const checksum = ripe_hash.slice(0, 4);
    const base58_sig = binary_to_base58(Uint8Array.from([...raw_sig, ...checksum]));
    return "SIG_K1_" + base58_sig;
}