Black Hat Python's #2:tcp agent

In the undergraduate completion of the time to contact the TCP agent this thing, then need to use a proxy to send and receive the data to make changes, while using the proxy also let me have a deeper understanding of the HTTP protocol.

One of the main things that TCP proxies use is the socket. The proxy connects localhost and remotehost through the socket, and then the traffic and data through proxy can be analyzed.

1 __author__='Seven'2 ImportSYS3 ImportSocket4 ImportThreading5 6 7 defHexdump (SRC, length=16):8result = []9digits = 4ifIsinstance (SRC, Unicode)Else2Ten  One      forIinchxrange (0, Len (src), length): As = src[i:i +Length] -Hexa = b' '. Join (["%0*x"% (digits, ord (x)) forXinchS]) -Text = b"'. join ([xif0x20 <= Ord (x) < 0x7FElseB'.'  forXinchS]) theResult.append (b"%04x%-*s%s"% (i, length * (digits + 1)), hexa, text)) -  -     PrintB'\ n'. Join (Result) -  +  - defReceive_from (connection): +Buffer ="" A  at     #We Set a 2 second time out depending in your target this may need to be adjusted -Connection.settimeout (2) -  -     Try: -          whileTrue: -data = CONNECTION.RECV (4096) in             if  notData: -                  Break toBuffer + =Data +     except: -         Pass the  *     returnBuffer $ Panax Notoginseng  - defrequest_handler (buffer): the     #Perform packet mofifications +     returnBuffer A  the  + defresponse_handler (buffer): -     #Perform pakect modifications $     returnBuffer $  -  - defProxy_handler (Client_socket, Remote_host, Remote_port, Receive_first): theRemote_socket =Socket.socket (socket.af_inet, socket. SOCK_STREAM) - Remote_socket.connect ((Remote_host, remote_port))Wuyi  the     ifReceive_first: -Remote_buffer =Receive_from (Remote_socket) Wu hexdump (Remote_buffer) -Remote_buffer =Response_handler (Remote_buffer) About         ifLen (remote_buffer): $             Print "[<==] sending%d bytes to localhost."%Len (remote_buffer) - client_socket.send (Remote_buffer) -  -      whileTrue: ALocal_buffer =Receive_from (Client_socket) +         ifLen (local_buffer): the             Print "[==>] Received%d bytes from localhost."%Len (local_buffer) - hexdump (Local_buffer) $Local_buffer =request_handler (Local_buffer) the remote_socket.send (Local_buffer) the             Print "[==>] Sent to remote." theRemote_buffer =Receive_from (Remote_socket) the         ifLen (remote_buffer): -             Print "[<==] Received%d bytes from remote."%Len (remote_buffer) in hexdump (Remote_buffer) theRemote_buffer =Response_handler (Remote_buffer) the client_socket.send (Remote_buffer) About             Print "[<==] Sent to localhost." the         if  notLen (Local_buffer)or  notLen (remote_buffer): the client_socket.close () the remote_socket.close () +             Print "[*] No more data. Closing connections." -  the              BreakBayi  the  the defServer_loop (Local_host, Local_port, Remote_host, Remote_port, Receive_first): -Server =Socket.socket (socket.af_inet, socket. SOCK_STREAM) -     Try: the Server.bind ((Local_host, local_port)) the     except: the         Print "[!!] Failed to listen on%s:%d"%(Local_host, Local_port) the         Print "[!!] Check for other listening sockets or correct permissions." - sys.exit (0) the     Print "[*] Listening on%s:%d"%(Local_host, Local_port) the  theServer.listen (5)94  the      whileTrue: theClient_socket, addr =server.accept () the         Print "[==>] Received incoming connection from%s:%d"% (Addr[0], addr[1])98Proxy_thread = Threading. Thread (target=Proxy_handler, Aboutargs=(Client_socket, Remote_host, Remote_port, Receive_first)) - Proxy_thread.start ()101 102 103 defMain ():104     ifLen (sys.argv[1:])! = 5: the         Print "Usage:./tcp proxy.py [localhost] [localport] [remotehost] [remoteport] [Receive_first]"106         Print "Example:./tcp proxy.py 127.0.0.1 9000 10.12.132.1 9000 True"107 sys.exit (0)108 109Local_host = sys.argv[1] thelocal_port = Int (sys.argv[2])111  theRemote_host = sys.argv[3]113remote_port = Int (sys.argv[4]) the  theReceive_first = sys.argv[5] the 117     if "True" inchReceive_first:118Receive_first =True119     Else: -Receive_first =False121 122 Server_loop (Local_host, Local_port, Remote_host, Remote_port, Receive_first)123 124  theMain ()

The data received can be modified in the request_handler and Response_handler functions.

The Hexdump function on the tall is from http://code.activestate.com/recipes/142812-hex-dumper/, which means that you can not understand how to read. If you have a friend that you can read, please talk to me.

Black Hat Python's #2:tcp agent