memeproxy.py

import sys
import socket
import threading
def server_loop(local_host,local_port,remote_host,remote_port,receive_first):
	
	server = socket.socket(socket.AF_INET, socket.SOCK_STREAM)

	try:
		server.bind((local_host,local_port))
	except:
		print "!Failed to listen on %s %d" % (local_host, local_port)
		print "!Check for other listening sockets or correct permissions"
		sys.exit(0)
	print "! Listening on %s%d" % (local_host,local_port)

	server.listen(5)

	while True:
		client_socket, addr = server.accept()

		#print out the local connection inf.
		print "[*] Received incoming connection from %s %d" % (addr[0],addr[1])

		#start a thread to talk to the remote host
		proxy_thread = threading.Thread(target=proxy_handler,
		args=(client_socket,remote_host,remote_port,receive_first))

		proxy_thread.start()

def proxy_handler(client_socket,remote_host,remote_port,receive_first):
	#connect to remote
	remote_socket = socket.socket(socket.AF_INET,socket.SOCK_STREAM)
	remote_socket.connect((remote_host,remote_port))

	#receive data from remote if necessary
	if receive_first:
		remote_buffer = receive_from(remote_socket)
		hexdump(remote_buffer)

		#send it to response handler
		remote_buffer = response_handler(remote_buffer)

		#if data exist send it to local client
		if len(remote_buffer):
			print "[*] Sending %d bytes to localhost. " % len(remote_buffer)
			client_socket.send(remote_buffer)
	while True:
		#read from host
		local_buffer = receive_from(client_socket)

		if len(local_buffer):
			print "received %d bytes from localhost." % len(local_buffer)
			hexdump(local_buffer)

			local_buffer = request_handler(local_buffer)

			remote_socket.send(local_buffer)
			print "[*] Sent to remote"

		remote_buffer = receive_from(remote_socket)

		if len(remote_buffer):
			print "[*] Beep-boop"
			hexdump(remote_buffer)
			
			remote_buffer = response_handler(remote_buffer)
			client_socket.send(remote_buffer)
			print "[*] Sent that shiat to local socket"

		#if no more data on either side, close connection
		if not len(local_buffer) or not len(remote_buffer):
			client_socket.close()
			remote_socket.close()
			print "[*] No more data. Closing connection"

			break

def hexdump(src, length=16):
	result = []
	digits = 4 if isinstance(src,unicode) else 2
	for i in xrange(0,len(src), length):
		s = src[i:i+length]
		hexa = b' '.join(["%0*X" % (digits, ord(x))	for x in s])
		text = b''.join([x if 0x20 <= ord(x) < 0x7F else b'.'	for x in s])

		result.append(b"%04X  %-*s   %s" % (i,length*(digits + 1), hexa, text))

	print b'\n'.join(result)

def receive_from(connection):

	buffer = ""
	#We set a 2 second timeout; depending on your 
	#target this may need to be adjusted
	connection.settimeout(2)

	try:
		while True:
			data = connection.recv(4096)
			if not data:
				break
			buffer += data

	except:
		pass

	return buffer

def request_handler(buffer):
	#perform packet modifications for remote host
	return buffer

def response_handler(buffer):
	#perform packet modifications for local host
	return buffer

def main():
	#dont need to parse cmd line here
	if len(sys.argv[1:]) != 5:
		print "Usage: ./proxy.py [localhost] [localport] [remotehost] [remoteport] [receive_first]"
		print "Example: ./proxy.py 127.0.0.1 9000 12.12.132.1 9000 True"
		sys.exit(0)

	#setup local listening parameters
	local_host = sys.argv[1]
	local_port = int(sys.argv[2])

	#setup remote
	remote_host = sys.argv[3]
	remote_port = sys.argv[4]

	#set boolean
	receive_first = sys.argv[5]

	if "True" in receive_first:
		receive_first = True
	else:
		receive_first = False

	#spin up listening socket
	server_loop(local_host,local_port,remote_host,remote_port,
	receive_first)

main()