cnigma

Facebook Conceal and RSA utilities for js

Compatible with Facebook Conceal 2.0

Usage

Conceal

const { Conceal } = require('cnigma');
const conceal = new Conceal('my-password');
 
// or
const conceal = new Conceal('my-password', myKey, encoding);
// encoding: hex or base64
// myKey: 32 bytes with ${encoding} encoded string

String

const plain = 'hello world @ 2020';
const encrypted = conceal.encryptStr(plain);
const decrypted = conceal.decryptStr(encrypted);

File

const srcFilePath = 'test/xxy007.png';
const encFilePath = 'test/xxy007.png.enc';
const decFilePath = 'test/xxy007.dec.png';
 
conceal
  .encryptFile(path, encFilePath)
  .then(() => conceal.decryptFile(encFilePath, decFilePath))
  .then(() => {
    console.log('done');
  })
  .catch((err) => {
    console.log(err);
  });

Using in browser

<script src="https://cdn.jsdelivr.net/npm/almond@0.3.3/almond.min.js"></script>
<script src="./cnigma.bundle.js"></script>
 
<script>
  const { Conceal, Rsa } = require('cnigma');
  const conceal = new Conceal('my-password');
 
  (async () => {
    const plain = 'hello world @ 2020';
    const encrypted = await conceal.encryptStr(plain);
    const decrypted = await conceal.decryptStr(encrypted);
  })();
</script> 

RSA

const { Rsa } = require('cnigma');
 
const privateKey = fs.readFileSync('rsa-private.pem', 'utf8');
const publicKey = fs.readFileSync('rsa-public.pem', 'utf8');
 
const rsa = new Rsa(rsaPrivateKey, rsaPublicKey, 'base64');
 
const plain = 'hello world @ 2020';
const signed = rsa.sign(plain);
const verified = rsa.verify(plain, signed);
const encrypted = rsa.encrypt(plain);
const decrypted = rsa.decrypt(encrypted);

FAQ

Private Key

The header -----BEGIN RSA PRIVATE KEY----- in the PEM file is reserved to PKCS#1 keys, but WebCryptoApi does not support pkcs1, so you need to convert the key from pkcs1 to pkcs8 using a tool like openssl

openssl pkcs8 -topk8 -inform PEM -outform PEM -nocrypt -in pkcs1.key -out pkcs8.key

RSA-OAEP-SHA1

Openssl has OAEP padding hardcoded using SHA1