#!/usr/bin/env python3
# -*- coding: utf-8 -*-
"""
Created on Mon Jun 22 19:15:47 2020
@author: edoardottt
"""
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_port, local_host))
except:
print("[!!] Failed to listen on {}:{}".format(local_host, local_port))
print("[!!] Check for other listening sockets or correct permissions.")
sys.exit(0)
print("[*] Listening on {}:{}". format(local_host, local_port))
server.listen(5)
while True:
client_socket, addr = server.accept()
# print out the local connection information
print("[==>] Received incoming connection from {}:{}".format(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()
# this is a pretty hex dumping function directly taken from
# the comments here:
# https://code.activestate.com/recipes/142812-hex-dumper/
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".format(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".format(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:
# keep reading into the buffer until
# there's no more data
# or we time out
while True:
data = connection.recv(4096)
if not data:
break
buffer += data
except:
pass
return buffer
# modify any requests defined for the remote host
def request_handler(buffer):
# perform packet modifications
return buffer
# modify any responses destined for the local host
def response_handler(buffer):
# perform packet modifications
return buffer
def proxy_handler(client_socket, remote_host, remote_port, receive_first):
# connect to the remote host
remote_socket = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
remote_socket.connect((remote_host, remote_port))
# receive data from the remote end if necessary
if receive_first:
remote_buffer = receive_from(remote_socket)
hexdump(remote_buffer)
# send it to our response handler
remote_buffer = response_handler(remote_buffer)
# if we have data to send to out client, send it
if len(remote_buffer):
print("[<==] Sending {} bytes to localhost".format(len(remote_buffer)))
client_socket.send(remote_buffer)
# now lets loop and read from local,
# send to remote, send to local,
# rinse, wash, repeat.
while True:
# read from local host
local_buffer = receive_from(client_socket)
if len(local_buffer):
print("[==>] Received {} bytes from localhost".format(len(local_buffer)))
hexdump(local_buffer)
# send it to our request handler
local_buffer = request_handler(local_buffer)
# send off the data to the remote host
remote_socket.send(local_buffer)
print("[==>] Sent to remote.")
# receive back the response
remote_buffer = receive_from(remote_socket)
if len(remote_buffer):
print("[<==] Received {} bytes from remote".format(len(remote_buffer)))
hexdump(remote_buffer)
# send to our response handler
remote_buffer = response_handler(remote_buffer)
# send the response to the local socket
client_socket.send(remote_buffer)
print("[<==] Sent to localhost.")
# if no more data on either side, close the connections
if not len(local_buffer) or not len(remote_buffer):
client_socket.close()
remote_socket.close()
print("[*] No more data. Closing connections.")
break
def main():
# no fancy command-line parsing here
if len(sys.argv[1:]) != 5:
print("Usage: python3 proxy.py [localhost] [localport] [remotehost] [remoteport] [receive_first]")
print("Example: python3 proxy.py 127.0.0.1 9000 10.12.132.1 9000 True")
# setup local listening parameters
local_host = sys.argv[1]
local_port = int(sys.argv[2])
# setup remote target
remote_host = sys.argv[3]
remote_port = int(sys.argv[4])
# this tells our proxy to connect and receive data
# before sending to the remote host
receive_first = sys.argv[5]
if "True" in receive_first:
receive_first = True
else:
receive_first = False
# now spin up our listening socket
server_loop(local_host, local_port, remote_host, remote_port, receive_first)
main()