Node.js hashing of passwords

Question

I am currently using the following for hashing passwords:

var pass_shasum = crypto.createHash(\'sha256\').update(req.body.password).digest(\'hex\');

Answer 1

Bcrypt isn't a bad choice, but there are a few gotchas:

1. It will truncate on NUL bytes.
2. It will truncate after 72 characters. If you're using passphrases, this might weaken your password unexpectedly.

As of October 2019, Argon2id is the optimal choice.

The preferred way of interfacing with Argon2id is through libsodium (a cryptography library that provides a lot of features). There are several bindings to choose from, but the easiest is probably sodium-plus.

const SodiumPlus = require('sodium-plus').SodiumPlus;
let sodium;
(async function(){
    if (!sodium) sodium = await SodiumPlus.auto(); // Autoload the backend

    let password = 'Your example password goes here. Provided by the user.';

    // Hashing...
    let hash = await sodium.crypto_pwhash_str(
        password,
        sodium.CRYPTO_PWHASH_OPSLIMIT_INTERACTIVE,
        sodium.CRYPTO_PWHASH_MEMLIMIT_INTERACTIVE
    );
    // You can safely store {hash} in a database.

    // Checking that a stored hash is still up to snuff...
    let stale = await sodium.crypto_pwhash_str_needs_rehash(
        hash,
        sodium.CRYPTO_PWHASH_OPSLIMIT_INTERACTIVE,
        sodium.CRYPTO_PWHASH_MEMLIMIT_INTERACTIVE
    );
    if (stale) {
        // Rehash password, update database
    }

    // Password verification
    let valid = await sodium.crypto_pwhash_str_verify(password, hash);
    if (valid) {
        // Proceed...
    }
})();

The documentation for sodium-plus on Github includes password hashing and storage.