How can I hash a string with Node.js

[janbaer]

You can use the builtin crypto module for that.

const crypto = require('crypto');

function hashPassword(password, salt, algorithm='sha256'){
    let hash = crypto.createHmac(algorithm, salt); 
    hash.update(password);
    let value = hash.digest('hex');

    return {
        salt: salt,
        passwordHash: value
    };
}

See also this article