Encrypt text in Node.js and Decrypt from iOS app

Question

I'm using the solution here current to encrypt text from Node.js and decrypt from an iOS app. https://stackoverflow.com/a/27893935/2977578

The encryption from Node.js works but CryptoJS is very slow. I'm trying to port this code to use the built-in crypto module in Node.js for speed but I'm not an expert in these functions. Is it possible to get this code to work just using the built-in crypto module?

var password = "...";
var salt = "...";
var iv64 = "...";
var hash = CryptoJS.SHA256(salt);
var key = CryptoJS.PBKDF2(password, hash, { keySize: 256/32, iterations: 1000 });
var iv  = CryptoJS.enc.Base64.parse(iv64);
var encrypted = CryptoJS.AES.encrypt(message, key, { iv: iv });
return encrypted.ciphertext.toString(CryptoJS.enc.Base64);

Answer 1

I've implemented this encryption logic using the built-in Node.js crypto module, I've encrypted the same plaintext using both the crypto-js function as well and decoded both to ensure the results are consistent:

const CryptoJS = require('crypto-js');
const crypto = require("crypto");

function encrypt_cryptojs(message, password, iv64, salt) {
    var hash = CryptoJS.SHA256(salt);
    var key = CryptoJS.PBKDF2(password, hash, { keySize: 256/32, iterations: 1000 });
    var iv  = CryptoJS.enc.Base64.parse(iv64);
    var encrypted = CryptoJS.AES.encrypt(message, key, { iv: iv });
    return encrypted.ciphertext.toString(CryptoJS.enc.Base64);
}

// Use built-in crypto module.
function encrypt(message, password, iv64, salt) {
    const iv = Buffer.from(iv64, 'base64');
    const hash = crypto.createHash('sha256').update(salt, 'utf8').digest()
    const key = crypto.pbkdf2Sync(password, hash, 1000, 32, null);

    const cipher = crypto.createCipheriv('aes-256-cbc', key, iv);
    let encrypted = cipher.update(message, 'utf8', 'base64')
    encrypted += cipher.final('base64');
    return encrypted;
}

function decrypt(messagebase64, password, iv64) {

    const iv = Buffer.from(iv64, 'base64');
    const hash = crypto.createHash('sha256').update(salt, 'utf8').digest()
    const key = crypto.pbkdf2Sync(password, hash, 1000, 32, null);

    const decipher = crypto.createDecipheriv('aes-256-cbc', key, iv);
    let decrypted = decipher.update(messagebase64, 'base64');
    decrypted += decipher.final();
    return decrypted;
}

const plaintext = "If you prick us do we not bleed? If you tickle us do we not laugh";
const salt = "some salt";
const password = crypto.scryptSync("some password", salt, 16).toString("base64");
const iv64 = "XxbSho8OZacvQwXC6S5RQw==";

console.log("Ciphertext (crypto js):", encrypt_cryptojs(plaintext, password, iv64, salt));
console.log("Ciphertext (built-in crypto module):", encrypt(plaintext, password, iv64, salt));
console.log("Decrypted (crypto js):", decrypt(encrypt_cryptojs(plaintext, password, iv64, salt), password, iv64));
console.log("Decrypted (built-in crypto module):", decrypt(encrypt(plaintext, password, iv64, salt), password, iv64));