Simple subscriber: using Beebotte MQTT with secure connection, AES 256 encrypted data, QoS level 1

bbt_mqtt_sub.js

// Copyright (c) 2013-2014 Beebotte <contact@beebotte.com>
// This program is published under the MIT License (http://opensource.org/licenses/MIT).

/////////////////////////////////////////////////////////////
// This code uses the Beebotte API, you must have an account.
// You can register here: http://beebotte.com/register
/////////////////////////////////////////////////////////////

var mqtt = require('mqtt')
var crypto = require('crypto');

//AES Cipherer
var aesCipher = function(opts) {
  opts = opts || {};
  this.algo = opts.algo || 'aes-256-cbc';
  this.inputEncoding = opts.inputEncoding || 'utf8';
  this.outputEncoding = opts.outputEncoding || 'base64';
  this.key = '1234567890'; //Ciphering Key

  //encrypts given data
  this.encrypt = function(data) {
    var cipher = crypto.createCipher(this.algo, this.key);
    var encrypted = cipher.update(data, this.inputEncoding, this.outputEncoding);
    encrypted += cipher.final(this.outputEncoding);

    return encrypted;
  }

  //decrypts given encrypted data
  this.decrypt = function(encrypted) {
    var decipher = crypto.createDecipher(this.algo, this.key);
    var deciphered = decipher.update(encrypted, this.outputEncoding, this.inputEncoding);
    deciphered += decipher.final(this.inputEncoding);
    return deciphered;
  }
}

//Creates a secure (SSL) MQTT connection. Username is your private Key.
client = mqtt.createSecureClient(8883, 'mqtt.beebotte.com', {username: 'YOU_SECRET_KEY', password: ''});

aes = new aesCipher();

client.on('message', function (topic, message) {
  //decrypt message
  decrypted_msg = aes.decrypt(message);
  console.log(topic + '   ' + decrypted_msg);
});

//Subscribe with QoS 1
client.subscribe('mychannel/resource', {qos: 1});