yescrypt-wasm/example.js

WebAssembly module for Yescrypt

// Reproduction / regression check for the "20x a password" bug (WASM build).
//
// Mirrors node/example.js: hashes a 19-byte and a 20-byte all-"a" password with
// fixed salts and compares the encoded "$y$..." output against the known-good
// values. Before the fix, the 20-byte case mismatched because the password was
// copied to the WASM heap without a NUL terminator and the C side used strlen().
//
// Run:  node wasm/example.js   (from the repo root, after `cd wasm && yarn && yarn build`)

import { Yescrypt } from './lib/index.js';

const cases = [
    {
        label: '19x "a"',
        passwd: 'a'.repeat(19),
        saltHex: '26295eb2e1cdfc39dbf3214f97d00d8b',
        expected: '$y$j9T$aYWLm4Snwbnqn5mHL0R190$5MqtyafwmqbTiv/BCpiU9XWsB850JFOmy8BW7quc1iA',
    },
    {
        label: '20x "a"',
        passwd: 'a'.repeat(20),
        saltHex: '91270e9036831730a9d82fc0937c4ceb',
        expected: '$y$j9T$FSW1EOnUL.HeMz0kHm5Hf1$cq6E0/qPVBPCNCQErax5j/.1nE7dRDKNZEAHbdwYtq7',
    },
];

const toBytes = (str) => new TextEncoder().encode(str);
const hexToBytes = (hex) => Uint8Array.from(hex.match(/.{1,2}/g).map((b) => parseInt(b, 16)));
const bytesToHex = (bytes) =>
    Array.from(bytes)
        .map((b) => b.toString(16).padStart(2, '0'))
        .join('');

async function main() {
    const yescrypt = await Yescrypt.init();

    let failures = 0;

    for (const { label, passwd, saltHex, expected } of cases) {
        const passwdBytes = toBytes(passwd);
        const saltBytes = hexToBytes(saltHex);

        const result = yescrypt.yescrypt_hash(passwdBytes, saltBytes);
        const ok = result === expected;

        console.log(`[wasm] passwd with ${label}`);
        console.log(`  salt hex:     ${saltHex}`);
        console.log(`  password hex: ${bytesToHex(passwdBytes)}`);
        console.log(`  result:       ${result}`);
        console.log(`  expected:     ${expected}`);
        console.log(`  ${ok ? 'OK' : 'MISMATCH'}\n`);

        if (!ok) {
            failures++;
        }
    }

    if (failures) {
        console.error(`[wasm] ${failures} case(s) FAILED`);
        process.exit(1);
    }
    console.log('[wasm] all cases passed');
}

main().catch((err) => {
    console.error(err);
    process.exit(1);
});