#!/usr/bin/env python2.7

from Crypto.Cipher import AES
import binascii, sys
import itertools

#KEY = "yn9RB3Lr43xJK2██".encode()
#IV  = "████████████████".encode()

msg = "AES with CBC is very unbreakable".encode()

#aes = AES.new(KEY, AES.MODE_CBC, IV)
#print (binascii.hexlify(aes.encrypt(msg)).decode())

# output:
# c5██████████████████████████d49e78c670cb67a9e5773d696dc96b78c4e0

plausible = "abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ0123456789="

pairs_of_characters = list((itertools.product(plausible, repeat=2)))

lastblock = bytes.fromhex("78c670cb67a9e5773d696dc96b78c4e0")

for pair in pairs_of_characters:
    IV = b"\x00" * 16
    pair = str(''.join(pair))
    KEY = ("yn9RB3Lr43xJK2" + pair ).encode()
    #print(KEY)
    aes = AES.new(KEY, AES.MODE_CBC, IV)

    pt2 = b"very unbreakable"


    ciphertext = aes.decrypt(lastblock)
    #print(ciphertext)
    if ciphertext[0] ^ 0xc5 == b"v" and ciphertext[14] ^ 0xd4 == b"l" and ciphertext[15] ^ 0x9e == b"e":
        print("Found key: " + KEY.decode())