def verify_cipher(cipher_name, key_word=''):
""" Main method to test ciphers """
# Instantiate cipher
cipher = None
if cipher_name == 'caesar':
cipher = Caesar()
elif cipher_name == 'multiplication':
cipher = Multiplication()
elif cipher_name == 'affine':
cipher = Affine()
elif cipher_name == 'unbreakable':
cipher = Unbreakable()
elif cipher_name == 'rsa':
cipher = RSA()
else:
raise Exception('Cipher name not recognised')
print(('\nTesting %s cipher:\n' % cipher_name).upper())
# Define sender and receiver
sender = Sender(cipher)
receiver = Receiver(cipher)
# Distribute key(s)
if cipher_name == 'unbreakable':
encryption_key, decryption_key = cipher.generate_keys(key_word)
else:
encryption_key, decryption_key = cipher.generate_keys()
sender.set_key(encryption_key)
receiver.set_key(decryption_key)
# Create message and send it
message = "Hello world"
# message = "aaaaaaaaaaa"
sender.send(message, receiver)
print("\nSender message: ", sender.message)
print("Sender encoded: ", sender.encoded_message)
print("Receiver encoded:", receiver.encoded_message)
print("Receiver decoded:", receiver.message)
hack = input('\nDo you want to try and hack this message? (y/n): ')
if hack == 'y':
hacker = Hacker(cipher)
if cipher_name in ('caesar', 'multiplication'):
hacker.hack_caesar_or_multiplication(sender.encoded_message)
elif cipher_name == 'affine':
hacker.hack_affine(sender.encoded_message)
elif cipher_name == 'unbreakable':
hacker.hack_unbreakable(sender.encoded_message)
else:
print('No can do :P')
class Affine:
""" Affine cipher """
def __init__(self):
self.caesar = Caesar()
self.multiplication = Multiplication()
def generate_keys(self):
""" Generates encryption and decryption key """
multiplication_encrypt, multiplication_decrypt = self.multiplication.generate_keys(
)
caesar_encrypt, caesar_decrypt = self.caesar.generate_keys()
encryption_key = (multiplication_encrypt, caesar_encrypt) # (48, 90)
decryption_key = (multiplication_decrypt, caesar_decrypt) # (2, 5)
return encryption_key, decryption_key
def encode(self, message, key):
""" Encode message with given key """
multiplication_key = key[0]
caesar_key = key[1]
# Encode with Multiplication then Caesar
partially_encoded = self.multiplication.encode(message,
multiplication_key)
encoded_message = self.caesar.encode(partially_encoded, caesar_key)
return encoded_message
def decode(self, encoded_message, decryption_keys):
""" Decode the encoded message with the decryption key """
multiplication_key = decryption_keys[0]
caesar_key = decryption_keys[1]
# Decode with Caesar then Multiplication
partially_decoded = self.caesar.decode(encoded_message, caesar_key)
decoded_message = self.multiplication.decode(partially_decoded,
multiplication_key)
return decoded_message
class Hacker(Receiver):
'''Hacker class'''
def __init__(self, cipher):
self.cipher = cipher
def english_words(self):
'''List of the txt file'''
file = open('english_words.txt')
return file.read().splitlines()
def brute_force(self, cipher, crypt_key):
'''Brute force method'''
words = self.english_words()
for key in cipher.possible_keys():
if isinstance(cipher, Affine):
for key_two in cipher.possible_keys():
self.set_key([key, key_two])
if self.operate_cipher(cipher, crypt_key) in words:
return self.operate_cipher(cipher, crypt_key)
else:
self.set_key(key)
if words.__contains__(self.operate_cipher(cipher, crypt_key)):
return self.operate_cipher(cipher, crypt_key)
return "None of the possible keys could decrypt the encrypted word"
c = Caesar()
h = Hacker(c)
print(h.brute_force(c, c.encode("hello", c.generate_keys())))
