Node Crypto JS

Introduction

Node Crypto JS is a NodeJS (RSA+AES) encryption and decryption companion for hybrid-crypto-js. Node Crypto JS combines RSA and AES encryption algorithms making it possible to efficiently encrypt and decrypt large messages. This node library is based on hybrid-crypto-js.

Documentation

Getting started

• Introduction
• Documentation
• Installation

Features

• Initialization
• Encryption
• Decryption
• Signatures
• Verifying
• RSA keypairs

Installation

npm install node-crypto-js

Importing

Node.js

1var RSA = require('node-crypto-js').RSA;
2var Crypt = require('node-crypto-js').Crypt;

Features

Initialization

1// Basic initialization
2var crypt = new Crypt();
3var rsa = new RSA();
4
5// Increase amount of entropy
6var entropy = 'Random string, integer or float';
7var crypt = new Crypt({ entropy: entropy });
8var rsa = new RSA({ entropy: entropy });

Encryption

Node Crypto JS provides basic encryption function which supports also multiple RSA keys, with or without signature. Encrypted message is outputted as a JSON string.

1var message = 'Hello world!';
2
3// Encryption with one public RSA key
4var encrypted = crypt.encrypt(publicKey, message);
5
6// Function also supports encryption with multiple RSA public keys
7var encrypted = crypt.encrypt([publicKey1, publicKey2, publicKey3], message);
8
9// Encryption with signature
10var encrypted = crypt.encrypt(publicKey, message, signature);

Pretty-printed sample output

1{
2    "v": "node-crypto-js_0.1.2",        // Current package version
3    "iv": "CmtyaZTyzoAp1mTNUTztic0v1...", // Initialization vector
4    "keys": {                             // Encrypted AES keys by RSA fingerprints
5        "85:3d:10:e1:56...": "bHaTF9...",
6        "d3:48:6a:e9:13...": "t9eds3..."
7    },
8    "cipher": "+iwVFsC2dECBQvwcm9DND..."  // Actual encrypted message
9    "signature": "sdL93kfdm12feds3C2..."  // Signature (optional)
10}
11

Decryption

Decrypting message with Hybrid Crypto JS is as easy as encrypting. Decryption function can decrypt any message which has been encrypted with keypair's public key. Decrypted message is outputted as a JSON object.

1var encrypted = '{"v":"node-crypto-js_0.1.0","iv":"CmtyaZTyzoAp1mTN...';
2
3// Decrypt encryped message with private RSA key
4var decrypted = crypt.decrypt(privateKey, encrypted);
5
6// Get decrypted message
7var message = decrypted.message;

Sample output

1{
2    message: "Hello world!",            // Actual decrypted message
3    signature: "sdL93kfdm12feds3C2..."  // Signature (optional)
4}

Signatures

Hybrid Crypto JS provides simple message signing. When issuer signs a message, message receiver can be sure of the message issuer.

1var message = 'Hello world!';
2
3// Create a signature with ISSUER's private RSA key
4var signature = crypt.signature(issuerPrivateKey, message);
5
6// Encrypt message with RECEIVERS public RSA key and attach the signature
7var encrypted = crypt.encrypt(receiverPublicKey, message, signature);

Verifying

Message receiver needs to have message issuer's public RSA key in order to verify message issuer.

1// Encrypted message with signature
2var encrypted = '{"v":"hybri... ..."signature":"sdL93kfd...';
3
4// Decrypt message with own (RECEIVER) private key
5var decrypted = crypt.decrypt(receiverPrivateKey, encrypted);
6
7// Verify message with ISSUER's public key
8var verified = crypt.verify(
9  issuerPublicKey,
10  decrypted.signature,
11  decrypted.message
12);

Verification function return true or false depending on whether the verification was successfull.

RSA keypairs

Hybrid Crypto JS RSA key generation function is based in Forge key pair generation function. As a difference Hybrid Crypto JS returns keypair in PEM format.

1// Initialize RSA-class
2var rsa = new RSA();
3
4// Generate RSA key pair, defaults on 4096 bit key
5rsa.generateKeypair(function(keypair) {
6  // Callback function receives new keypair as a first argument
7  var publicKey = keypair.publicKey;
8  var privateKey = keypair.privateKey;
9});
10
11// Generate 1024 bit RSA key pair
12rsa.generateKeypair(function(keypair) {
13  // Callback function receives new 1024 bit keypair as an argument
14  var publicKey = keypair.publicKey;
15  var privateKey = keypair.privateKey;
16}, 1024); // Key size
17
18// RSA can be also initialized with options
19var rsa = new RSA({
20  keySize: 4096,
21  rsaStandard: 'RSA-OAEP' // RSA-OAEP or RSAES-PKCS1-V1_5,
22});