encryption server

ECB_server.py

#/usr/bin/env python
from Crypto.Cipher.AES import AESCipher

import SocketServer,threading,os,time
import signal

from secret2 import FLAG, KEY

PORT = 7765

def pad(s):
  l = len(s)
  needed = 16 - (l % 16)
  return s + (chr(needed) * needed)

def encrypt(s):
  return AESCipher(KEY).encrypt(pad('ENCRYPT:' + s.decode('hex') + FLAG))

class incoming(SocketServer.BaseRequestHandler):
    def handle(self):
        atfork()
        req = self.request

        def recvline():
            buf = ""
            while not buf.endswith("\n"):
                buf += req.recv(1)
            return buf
        signal.alarm(5)

        req.sendall("Send me some hex-encoded data to encrypt:\n")
        data = recvline()
        req.sendall("Here you go:")
        req.sendall(encrypt(data).encode('hex') + '\n')
        req.close()

class ReusableTCPServer(SocketServer.ForkingMixIn, SocketServer.TCPServer):
  pass

SocketServer.TCPServer.allow_reuse_address = True
server = ReusableTCPServer(("0.0.0.0", PORT), incoming)

print "Server listening on port %d" % PORT
server.serve_forever()