cryptohack_gotta_go_fast.py

import json
import socket

s = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
s.connect(("socket.cryptohack.org", 13372))

s.recv(64)
s.sendall(b'{"option": "encrypt_data", "input_data": "0000000000000000000000000000000000000000000000000000000000000000"}')
data = json.loads(s.recv(64))
key = bytes.fromhex(data['encrypted_data'])

s.sendall(b'{"option": "get_flag"}')
data = json.loads(s.recv(64))
flag = bytes.fromhex(data['encrypted_flag'])

msg = ''
for i in range(len(flag)):
  msg += chr(key[i] ^ flag[i])

print(msg)