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()