from base64 import b64encode
from Crypto.Random import get_random_bytes
from Crypto.Cipher import ChaCha20_Poly1305
from pathlib import Path
from zlib import compress

flag = Path("flag.txt").read_bytes()
key = get_random_bytes(32)

try:
    while True:
        append = input("Append whatever you want to the flag: ").encode()
        # gotta save on bandwidth!
        m = compress(flag + append)
        cipher = ChaCha20_Poly1305.new(key=key)
        c, tag = cipher.encrypt_and_digest(m)
        res = cipher.nonce + tag + c
        print(b64encode(res).decode())
except (KeyboardInterrupt, EOFError):
    pass