Solved Pirates Challenge

from Crypto.Cipher import AES
from Crypto.Hash import MD5
import struct
import hashlib

class brute:

    def __init__(self):
        self.goal = 'ce975cc4578f4a7005f22ad7182a4d7640a00bd18c6f27c479cebfb1d1778c8b'
        self.choices = list('QWERTZUIOPASDFGHJKLYXCVBNM1234567890')
        self.index = {'1a' : 0, '1b' : 0, '1c' : 0, '1d' : 0, '2a' : 0, '2b' : 0, '2c' : 0, '2d' : 0}
        self.winners = []
        self.won = False
        self.allDone = False
        self.mainLoop()

    def buildKey1(self, one, two, three, four):
        key = '8643-' + one + '120-' + two + 'D' + three + '3-' + four + '893'
        return key

    def buildKey2(self, one, two, three, four):
        key = 'E5' + one + 'D-' + two + '722-' + three + '2E8-6' + four + '85'
        return key

    def createCipher(self, key1, key2):
        key = key1
        blanks = '\0' * 16
        h = MD5.new()
        h.update(key2)
        IV = h.digest()           # Initialization vector: discussed later
        mode = AES.MODE_CBC
        encryptor = AES.new(key, mode, IV=IV)
        ciphertext = encryptor.encrypt(blanks)
        return ciphertext

    def checkCorrect(self, ciphertext):
        if ciphertext.encode('hex') == self.goal[:32]:
            return True
        else:
            #print ciphertext.encode('hex') + ' failed!'
            return False

    def mainLoop(self):
        while not self.won:
            #1A
            if self.allDone:
                print 'Whole index was searched!'
            #2B
            if self.index['2a'] == 35:
                self.index['2a'] = 0
                self.index['2b'] = self.index['2b'] + 1
            else:
                self.index['2a'] = self.index['2a'] + 1
            if self.index['2b'] == 35:
                self.index['2b'] = 0
                self.index['2c'] = self.index['2c'] + 1
            if self.index['2c'] == 35:
                self.index['2c'] = 0
                self.index['2d'] = self.index['2d'] + 1
            if self.index['2d'] == 35:
                self.index['2d'] = 0
                self.allDone = True

            sha = hashlib.sha1()
            sha.update('8643-C120-EDA3-F893')
            before = sha.digest()
            key1 = before[:16]
            key2 = self.buildKey2(self.choices[self.index['2a']], self.choices[self.index['2b']], self.choices[self.index['2c']], self.choices[self.index['2d']])

            result = self.createCipher(key1, key2)
            victory = self.checkCorrect(result)
            if victory == True:
                self.won = True
                self.winners.append('8643-C120-EDA3-F893')
                self.winners.append(key2)
            else:
                #print self.choices[self.index['2a']], self.choices[self.index['2b']], self.choices[self.index['2c']], self.choices[self.index['2d']]
                pass

        print 'Keys found!'
        print self.winners

brute = brute()