sandesh.py

# sandesh_client

import base64
import sys, socket, select
from Crypto.Cipher import AES
import os
import hashlib
import signal

os.system("clear")
print """
      
   _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _  _ _
       ___  ____       ___  __    ___
 |    / __// __ \|\ ||| _ \| _|  / __/||_||    |
     _\ \  ||__||||\||||_||| _| _\ \  | _ |     
 |  |___/  ||  |||| \||___/|__||__ /  || ||    |
         ||  SECRET-CHAT_ROOM||
 |       Created BY:Akumar7042                  |
  
 | _ _ _ _ _ _ _ _ _  _ _ _ _  _ _ _ _ _ _ _ _ _|



""" 
def sigint_handler(signum, frame):
    print '\n user interrupt ! shutting down'
    print "[info] shutting down SANDESH \n\n"
    sys.exit()	
    

signal.signal(signal.SIGINT, sigint_handler)

def hasher(key):
	hash_object = hashlib.sha512(key)
	hexd = hash_object.hexdigest()
	hash_object = hashlib.md5(hexd)
	hex_dig = hash_object.hexdigest()
	return hex_dig

def encrypt(secret,data):
	BLOCK_SIZE = 32
	PADDING = '{'
	pad = lambda s: s + (BLOCK_SIZE - len(s) % BLOCK_SIZE) * PADDING
	EncodeAES = lambda c, s: base64.b64encode(c.encrypt(pad(s)))
	cipher = AES.new(secret)
	encoded = EncodeAES(cipher, data)
	return encoded

def decrypt(secret,data):
	BLOCK_SIZE = 32
	PADDING = '{'
	pad = lambda s: s + (BLOCK_SIZE - len(s) % BLOCK_SIZE) * PADDING
	DecodeAES = lambda c, e: c.decrypt(base64.b64decode(e)).rstrip(PADDING)
	cipher = AES.new(secret)
	decoded = DecodeAES(cipher, data)
	return decoded


def chat_client():
    if(len(sys.argv) < 5) :
        print 'Usage : python sandesh.py <hostname> <port> <password> <nick_name>'
        sys.exit()

    host = sys.argv[1]
    port = int(sys.argv[2])
    key = sys.argv[3]
    key = hasher(key)	
    uname = sys.argv[4]

    s = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
    s.settimeout(2)


    try :
        s.connect((host, port))

    except :
        print "\033[91m"+'Unable to connect'+"\033[0m"
        sys.exit()

    print "Connected to host. You can start sending messages"
    sys.stdout.write("\033[34m"+'\n[Me :] '+ "\033[0m"); sys.stdout.flush()

    while 1:
        socket_list = [sys.stdin, s]
        read_sockets, write_sockets, error_sockets = select.select(socket_list , [], [])

        for sock in read_sockets:
            if sock == s:

                data = sock.recv(4096)

                if not data :
                    print "\033[91m"+"\nDisconnected from chat server"+"\033[0m"
                    sys.exit()
                else :
                    data = decrypt(key,data)
                    sys.stdout.write(data)
                    sys.stdout.write("\033[34m"+'\n[Me :] '+ "\033[0m"); sys.stdout.flush()

            else :

                msg = sys.stdin.readline()
                msg = '[ '+ uname +': ] '+msg
                msg = encrypt(key,msg)
                s.send(msg)
                sys.stdout.write("\033[34m"+'\n[Me :] '+ "\033[0m"); sys.stdout.flush()

if __name__ == "__main__":

    sys.exit(chat_client())