network --> python socket scripts

Network_and_802.11/socket/tcp_proxy.py

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+#!/usr/bin/env python
+
+__author__ = "bt3"
+
+
+import socket
+import threading
+import sys
+
+# Output the packet details with both hexadecimal and ASCII-printable
+# characters. Useful to understanding unknown protocols, finding user
+# credentials, etc.
+def hexdump(src, length=16):
+    result = []
+    digists = 4 if isinstance(src, unicode) else 2
+    for i in range(len(src), lenght):
+        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))
+
+# Used for receiving local and remote data, and pass in the socket object.
+def receive_from(connection):
+    buffer = ''
+
+    # set 2 second timeout
+    # mb too much if you are proxying to other countries
+    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
+    buffer += ' Yaeah!'
+    return buffer
+
+def response_handler(buffer):
+    # perform packet modifications
+    return buffer
+
+
+
+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 ))
+
+    # receive data from the remote if necessary
+    if receive_first:
+        remote_buffer = receive_from(remote_socket)
+        hexdump(remote_buffer)
+
+        # send it to the response handler
+        remote_buffer = response_handler(remote_buffer)
+
+        # if we have data to send to client, send it:
+        if len(remote_buffer):
+            print "[<==] Sending %d bytes to localhost." %len(remote_buffer)
+            client_socket.send(remote_buffer)
+
+
+    # loop and read from local, send to remote, send to local
+    while True:
+
+        local_buffer = receive_from(client_socket)
+        if len(local_buffer):
+            print "[==>] Received %d bytes from localhost." % 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."
+
+
+        remote_buffer = receive_from(remote_socket)
+        if len(remote_buffer):
+            print "[==>] Received %d bytes from remote." % len(remote_buffer)
+            hexdump(remote_buffer)
+
+            # send it to our response handler
+            remote_buffer = response_handler(remote_buffer)
+
+            # send off the data to the remote host
+            client_socket.send(remote_buffer)
+            print "[==>] Sent 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 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)
+        sys.exit()
+
+    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])
+
+        # 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 main():
+
+    if len(sys.argv[1:]) != 5:
+        print "Usage: ./proxy.py <localhost> <localport> <remotehost> <remoteport> <received_first>"
+        print "Example: ./proxy.py 127.0.0.1 9000 10.12.122.1 9999 True"
+        sys.exit()
+
+    # setup local remote target
+    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])
+
+    # tells the proxy to connect and receive data
+    # before sending to the remote host
+    if sys.argv[5] == 'True':
+        receive_first = True
+    else:
+        receive_first = False
+
+    # run the listening socket
+    server_loop(local_host, local_port, remote_host, remote_port, receive_first)
+
+if __name__ == '__main__':
+    main()