#!/usr/bin/env python2
# -*- coding: utf-8 -*-

import sys
from base64 import b64decode
from Crypto.Cipher import AES
from secretsharing import SecretSharer


def main():
    if len(sys.argv) < 4:
        print("Usage: {} part1 part2 part2".format(sys.argv[0]))
        exit(1)

    AES_KEY = SecretSharer.recover_secret([sys.argv[1], sys.argv[2], sys.argv[3]])
    IV = b'\x00' * 16
    cipher = AES.new(key=AES_KEY, mode=AES.MODE_CBC, iv=IV)

    with open("flag.enc", 'r') as flagfile:
        enc_flag = b64decode(flagfile.read())

    flag = cipher.decrypt(enc_flag)

    print("Decrypted flag is: {}".format(flag))


if __name__ == '__main__':
    main()
