Hash and encrypt data using the built-in crypto Node.js library

First see if the built-in Crypto module is available

let crypto;
try {
  crypto = require('node:crypto');
  console.log("we're good");
} catch (err) {
  console.log('crypto support is disabled!');
}
javascript

Create a SHA-256 hash

With the SHA-256 hashing algorithm, the text is converted to a unique "digest" which cannot be decrypted. The algorithm will always produce the same result, or key, and cannot be decrypted. This is useful for storing passwords in a database because you can ensure that the password they typed is correct without saving the password itself.

const { createHash } = require('node:crypto');

const msg = "Here's a super secret message to hash";

const hash = createHash('sha256').update(msg).digest('hex');

console.log(hash);

// Prints:
//   3e0e072b5af9cf7dd022e507bbcea46ea8e0054311b713e0129937ef60cf3f4c
javascript

(Theoretically hashing can be reversed, but the amount of computational energy required is unfeasible in almost all cases - the big exception being bitcoin mining).

Encrypt data with a Cipher

The Cipher class is used to encrypt data. Encryption is the process of turning readable text into unreadable "Ciphertext", which is used for sending messages without the risk of third-parties being able to read it. Unlike with hashing, the Ciphertext can be decrypted using the private key, or password.

const { scrypt, randomFill, createCipheriv } = require('node:crypto');

const msg = "Here's a super secret message to encrypt";

const algorithm = 'aes-192-cbc';
const password = 'Password used to generate key';

// First, we'll generate the key. The key length is dependent on the algorithm.
// In this case for aes192, it is 24 bytes (192 bits).
scrypt(password, 'salt', 24, (err, key) => {
  if (err) throw err;
  // Then, we'll generate a random initialization vector
  randomFill(new Uint8Array(16), (err, iv) => {
    if (err) throw err;

    const cipher = createCipheriv(algorithm, key, iv);

    let encrypted = cipher.update(msg, 'utf8', 'hex');
    encrypted += cipher.final('hex');
    console.log(encrypted);
  });
});
javascript