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Encryption Service
Challenge
See if you can break this!!
You can connect with nc 107.170.122.6 7765 and the source can be found here:
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#/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()
Solution
Flag