tcp proxy，可以在request_handler或者response_handler进行特殊修改，渗透测试或者协议故障测试的时候可以使用。要想支持ssl，只需connect处进行修改调整

__author__ = 'root'

import sys,socket,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 "[==>]Received incoming connection from %s:%d"%(addr[0],addr[1])

        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):

    remote_socket = socket.socket(socket.AF_INET, socket.SOCK_STREAM)

    remote_socket.connect((remote_host, remote_port))

    if receive_first:

        remote_buffer = receive_from(remote_socket)

        hexdump(remote_buffer)

        remote_buffer = response_handler(remote_buffer)

        if len(remote_buffer):

            print "[<==]Sending %d bytes to localhost" % (len(remote_buffer))

            client_socket.send(remote_buffer)

    while True:

        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 "[==>]Send to remote."

        remote_buffer = receive_from(remote_socket)

        if len(remote_buffer):

            print "[<==]Received %d bytes from remote."%len(remote_buffer)

            hexdump(remote_buffer)

            remote_buffer = response_handler(remote_buffer)

            client_socket.send(remote_buffer)

            print "[<==Send to localhost.]"

        if not len(local_buffer) or not len(remote_buffer):

            client_socket.close()

            remote_socket.close()

            print "[*]No more data.Closing connections."

            break

def hexdump(src,length = 16):

    result = []

    # resultText = []

    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 = ""

    connection.settimeout(2)

    try:

        while True:

            data = connection.recv(4096)

            if not data:

                break

            buffer += data

    except:

        pass

    return buffer

# modify any requests destined for the remote host

def request_handler(buffer):

    # perform packet modifications

    print '_________________________________________________________________________________________________'

    return buffer

# modify any responses destined for the local host

def response_handler(buffer):

    # perform packet

    print '_________________________________________________________________________________________________'

    return buffer

def main():

    # no fancy command-line parsing 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 10.12.132.1 9000 True"

        sys.exit(0)

    # setup local listening parameters

    local_host = sys.argv[1]

    local_port = int(sys.argv[2])

    # setup remote 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()