diff --git a/crypto/easy_pow/easy_pow.py b/crypto/easy_pow/easy_pow.py new file mode 100644 index 0000000..695ad20 --- /dev/null +++ b/crypto/easy_pow/easy_pow.py @@ -0,0 +1,67 @@ +from hashlib import sha256 +import socketserver +import signal +import string +import random +import os + + +class Task(socketserver.BaseRequestHandler): + def _recvall(self): + BUFF_SIZE = 2048 + data = b'' + while True: + part = self.request.recv(BUFF_SIZE) + data += part + if len(part) < BUFF_SIZE: + break + return data.strip() + + def send(self, msg, newline=True): + try: + if newline: + msg += b'\n' + self.request.sendall(msg) + except: + pass + + def recv(self, prompt=b'[-] '): + self.send(prompt, newline=False) + return self._recvall() + + def proof_of_work(self): + random.seed(os.urandom(8)) + proof = ''.join( + [random.choice(string.ascii_letters+string.digits) for _ in range(20)]) + _hexdigest = sha256(proof.encode()).hexdigest() + self.send(f"[+] sha256(XXXX+{proof[4:]}) == {_hexdigest}".encode()) + x = self.recv(prompt=b'[+] Plz tell me XXXX: ') + if len(x) != 4 or sha256(x+proof[4:].encode()).hexdigest() != _hexdigest: + return False + return True + + def handle(self): + signal.alarm(60) + if not self.proof_of_work(): + self.send(b'[!] Wrong!') + return + + self.send(b'here is your flag') + self.send(flag) + + +class ThreadedServer(socketserver.ThreadingMixIn, socketserver.TCPServer): + pass + + +class ForkedServer(socketserver.ForkingMixIn, socketserver.TCPServer): + pass + + +if __name__ == "__main__": + flag = bytes(os.getenv("FLAG"),"utf-8") + HOST, PORT = '0.0.0.0', 10001 + server = ForkedServer((HOST, PORT), Task) + server.allow_reuse_address = True + print(HOST, PORT) + server.serve_forever()