Enigma brute-forcer for http://www.maths.manchester.ac.uk/cryptography_competition_the_imitation_game/index.php

decode.py

from enigma.machine import EnigmaMachine
import string

# setup machine according to specs from a daily key sheet:

plug = 'LDERFAS'

for ch1 in string.ascii_uppercase:
    for ch2 in string.ascii_uppercase:
        for ch3 in string.ascii_uppercase:
            for ch4 in [x for x in string.ascii_uppercase if x not in plug]:
                machine = EnigmaMachine.from_key_sheet(
                       rotors='III I II',
                       reflector='B',
                       ring_settings='S B E',
                       plugboard_settings='LD ER FA S' + ch4)
                machine.set_display(ch1 + ch2 + ch3)
                ciphertext = 'RPVZLYNCQORVUSYUZUBCKNIBKDWZRPFZVLA'
                plaintext = machine.process_text(ciphertext)
                print plaintext + ' ' + ch1 + ch2 + ch3 + ' S' + ch4