def encrypt(plaintext: str) -> str:
plaintext = plaintext.replace(b';', b'%3B')
plaintext = plaintext.replace(b'=', b'%3D')
plaintext = b'comment1=cooking%20MCs;userdata=' + plaintext +\
b';comment2=%20like%20a%20pound%20of%20bacon'
cipher = aesCTR(KEY)
return cipher.encrypt(plaintext)
def decrypt(ciphertext: str) -> str:
cipher = aesCTR(KEY)
print(plaintext)
if b';admin=true;' in plaintext:
print('You did it!')
else:
print('Nope. Try again!')
def edit(ciphertext: str, offset: int, newtext: str) -> str:
cipher = aesCTR(KEY)
ciphertext = ciphertext[:offset] + newtext + ciphertext[offset + 1:]
return cipher.encrypt(ciphertext)
return output
KEY = keygen()
def edit(ciphertext: str, offset: int, newtext: str) -> str:
cipher = aesCTR(KEY)
ciphertext = ciphertext[:offset] + newtext + ciphertext[offset + 1:]
return cipher.encrypt(ciphertext)
if __name__ == '__main__':
plaintext = b''
with open('25.txt', 'r') as file:
plaintext = b64decode(file.read())
print(plaintext)
cipher = aesCTR(KEY)
ciphertext = cipher.encrypt(plaintext)
key = b''
for i in range(len(ciphertext)):
modified_ciphertext = edit(ciphertext, i, b'\x00')
key += bytes([modified_ciphertext[i]])
decrypted_plaintext = xor(ciphertext, key)
print(decrypted_plaintext)
print('Are they same -', plaintext == decrypted_plaintext)
if error_seen <= min_error:
outputs = [output]
keys = [key * len(input)]
min_error = error_seen
return outputs[0]
if __name__ == '__main__':
plaintexts = []
with open('20.txt', 'r') as file:
plaintexts = [b64decode(x) for x in file.read().splitlines()]
print(*plaintexts, sep='\n')
cipher = aesCTR('YELLOW SUBMARINE')
ciphertexts = [cipher.encrypt(plaintext) for plaintext in plaintexts]
#print(ciphertexts)
min_cipher_text_length = min(
[len(ciphertext) for ciphertext in ciphertexts])
ciphertexts = [ciphertext[:min_cipher_text_length] for ciphertext in\
ciphertexts]
#print(ciphertexts)
blocks = [b'' for _ in range(min_cipher_text_length)]
for i in range(min_cipher_text_length):
for ciphertext in ciphertexts:
blocks[i] += bytes([ciphertext[i]])
#print(blocks)