Encrypt and Decrypt Data in Node.js

Node.js provides 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 new directory anywhere in your system and create new project using the following command:

npm init -y

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

Encrypt and decrypt Nodejs

Encrypt and decrypt buffer

You can also encrypt and decrypt the buffers. Just pass the buffer in place of the string when you call the function and it should work.

Like this.

var hw = encrypt(Buffer.from("Some serious stuff","utf-8"))
console.log(hw)
console.log(decrypt(hw))

You can also pipe the streams in to the encrypt function to have secure encrypted data passing through the streams.

Conclusion

I hope the samples help you to get started with nodejs encryption.

If you have any questions or doubts, tweet me @codeforgeek or just leave a comment. I’ll reply as soon as possible.

Shahid (UnixRoot) Shaikh

Hey there, This is Shahid, an Engineer and Blogger from Bombay. I am also an Author and i wrote a programming book on Sails.js, MVC framework for Node.js.

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