Encrypt and Decrypt Data in Node.js

Node.js provides a built-in library called ‘crypto’ which you can use to perform cryptographic operations on data. You can do cryptographic operations on strings, buffer, and streams.

In this article, we will go through some examples of how you can do these operations in your project.

You can use multiple crypto algorithms. Check out the official Node.js docs here.

For the sake of examples, I am going to use AES (Advanced Encryption System) algorithm.

Create a new node.js project

Create a new directory anywhere in your system and create a new project using the following command:

npm init -y

If you have installed Node.js by manual build then there is a chance that the crypto library is not shipped with it. You can run this command to install the crypto dependency.

npm install crypto --save

You don’t need to do that if you have installed it using pre-built packages.

Let’s move ahead.

Encrypt and decrypt data (Strings, numbers etc)

// Nodejs encryption with CTR
const crypto = require('crypto');
const algorithm = 'aes-256-cbc';
const key = crypto.randomBytes(32);
const iv = crypto.randomBytes(16);

function encrypt(text) {
let cipher = crypto.createCipheriv('aes-256-cbc', Buffer.from(key), iv);
let encrypted = cipher.update(text);
encrypted = Buffer.concat([encrypted, cipher.final()]);
return { iv: iv.toString('hex'), encryptedData: encrypted.toString('hex') };
}

function decrypt(text) {
let iv = Buffer.from(text.iv, 'hex');
let encryptedText = Buffer.from(text.encryptedData, 'hex');
let decipher = crypto.createDecipheriv('aes-256-cbc', Buffer.from(key), iv);
let decrypted = decipher.update(encryptedText);
decrypted = Buffer.concat([decrypted, decipher.final()]);
return decrypted.toString();
}

var hw = encrypt("Some serious stuff")
console.log(hw)
console.log(decrypt(hw))

Here is the output: