"""Vigenère Cipher Dictionary Hacker
Implements a function that can hack a Vigenère cipher encrypted message using a dictionary.
Attributes:
DICTIONARY_FILE (str): String with absolute location of dictionary.txt file.
Note:
* https://www.nostarch.com/crackingcodes/ (BSD Licensed)
"""
from pythontutorials.books.CrackingCodesWithPython.Chapter11.detectEnglish import isEnglish
from pythontutorials.books.CrackingCodesWithPython.Chapter18.vigenereCipher import decryptMessage
DICTIONARY_FILE = "/home/jose/PycharmProjects/python-tutorials/pythontutorials/books/CrackingCodesWithPython/Chapter11/dictionary.txt"
[docs]def main():
from pyperclip import copy
ciphertext = """Tzx isnz eccjxkg nfq lol mys bbqq I lxcz."""
hackedMessage = hackVigenereDictionary(ciphertext)
if hackedMessage:
print('Copying hacked message to clipboard:')
print(hackedMessage)
copy(hackedMessage)
else:
print('Failed to hack encryption.')
[docs]def hackVigenereDictionary(ciphertext: str):
"""Hack Vigenère Dictionary
Brute-forces ciphertext by using every word in the dictionary file as a key. Checks if decrypted message is
English with the :func:`~books.CrackingCodesWithPython.Chapter11.detectEnglish.isEnglish` module, and prompts user
for confirmation by displaying first 100 characters.
Args:
ciphertext: String containing Vigenère cipher encrypted message.
Returns:
Decrypted message, if confirmed, None otherwise.
"""
fo = open(DICTIONARY_FILE)
words = fo.readlines()
fo.close()
for word in words:
word = word.strip() # Remove the newline at the end.
decryptedText = decryptMessage(word, ciphertext)
if isEnglish(decryptedText, wordPercentage=40):
# Check with user to see if the decrypted key has been found:
print()
print('Possible encryption break:')
print('Key ' + str(word) + ': ' + decryptedText[:100])
print()
print('Enter D for done, or just press Enter to continue breaking:')
response = input('> ')
if response.upper().startswith('D'):
return decryptedText
if __name__ == '__main__':
main()