import base64
import os
from utils import listener

FLAG = "crypto{????????????}"


def xor_flag_with_otp():
    flag_ord = [ord(c) for c in FLAG]
    otp = os.urandom(20)

    xored = bytearray([a ^ b for a, b in zip(flag_ord, otp)])

    # make sure our OTP doesnt leak any bytes from the flag
    for c, p in zip(xored, flag_ord):
        assert c != p

    return xored


class Challenge():
    def __init__(self):
        self.before_input = "No leaks\n"

    def challenge(self, your_input):
        if your_input == {"msg": "request"}:
            try:
                ciphertext = xor_flag_with_otp()
            except AssertionError:
                return {"error": "Leaky ciphertext"}

            ct_b64 = base64.b64encode(ciphertext)
            return {"ciphertext": ct_b64.decode()}
        else:
            self.exit = True
            return {"error": "Please request OTP"}


"""
When you connect, the 'challenge' function will be called on your JSON
input.
"""
listener.start_server(port=13370)