mqtt_encrypt_loop.py

import paho.mqtt.client as mqtt
from Crypto.Cipher import AES
import json, thread,time


MQTT_TOPIC_HOME = 'Raybaby'
MQTT_BROKER = 'iot.eclipse.org'
MQTT_PORT = 1883
sub_topic = "/stream/encrypt"


def send_ack(status):
    pub_topic = "/stream/encrypt"
    client.publish(pub_topic, MESSAGE)

def on_connect(client, userdata, flags, rc):
    MESSAGE = "Hi_I_am_Sooraj"
    print("Connected with result code " + str(rc))
    sub_topic = "/stream/encrypt"
    print 'sub_topic =' + sub_topic
    client.subscribe(sub_topic)
    time.sleep(2)
    pub_topic = "/stream/encrypt"
    obj = AES.new('expectoTrack6699', AES.MODE_CBC, 'coverMeTrack6699')

    spa = ''
    s = 16 - len(MESSAGE) % 16
    if s != 0:
        spa = ' ' * s
    MESSAGE = MESSAGE + spa

    ciphertext = obj.encrypt(MESSAGE)
    print "ciphertext: ", ciphertext
    data = ("".join("{:02x}".format(ord(c)) for c in ciphertext))
    client.publish(pub_topic, data)


def on_message(client, userdata, msg):
    print "got the message"
    print(msg.topic + " " + str(msg.payload))
    data = str(msg.payload)
    got_data = data.decode('hex')  # recieve data
    print "received tcpdata: ", data  # send this data
    print "received cipherdata: ", got_data  # send this data
    obj2 = AES.new('expectoTrack6699', AES.MODE_CBC, 'coverMeTrack6699')
    result = obj2.decrypt(got_data)
    print "decrypted result: ", result
    print "length of the result",len(result)
    print result.split(' ')[0]


    pub_topic = "/stream/encrypt"
    obj = AES.new('expectoTrack6699', AES.MODE_CBC, 'coverMeTrack6699')
    MESSAGE = "Hi_I_am_Sooraj"
    spa = ''
    s = 16 - len(MESSAGE) % 16
    if s != 0:
        spa = ' ' * s
    MESSAGE = MESSAGE + spa

    ciphertext = obj.encrypt(MESSAGE)
    print "ciphertext: ", ciphertext
    data = ("".join("{:02x}".format(ord(c)) for c in ciphertext))
    client.publish(pub_topic, data)


if __name__ == '__main__':
    while(1):
        try:
            client = mqtt.Client()
            client.connect(MQTT_BROKER, MQTT_PORT, 60)
            client.on_connect = on_connect
            client.on_message = on_message
            client.loop_forever()
        except Exception as e:
            print 'Exception found >>',e