def main(encrypt, input_file, output_file, block_cipher_mode, key_length):
if encrypt:
key = aes.random_key_generator(int(key_length))
if key_length == "128":
AES = aes.AES(key, 128)
elif key_length == "192":
AES = aes.AES(key, 192)
elif key_length == "256":
AES = aes.AES(key, 256)
if block_cipher_mode == "ECB":
bcm = aes.ECB(AES)
elif block_cipher_mode == "CBC":
bcm = aes.CBC(AES, 16)
elif block_cipher_mode == "CTR":
bcm = aes.CTR(AES)
bcm.cipher(input_file, output_file)
print("Cipher Key:", key)
write_key(key)
else:
key = read_key()
if key == 1:
print("File key.txt doesn't exists! Can't decrypt without key")
exit(1)
key_length = len(key) * 4
if key_length == 128:
AES = aes.AES(key, 128)
elif key_length == 192:
AES = aes.AES(key, 192)
elif key_length == 256:
AES = aes.AES(key, 256)
else:
print("Key length not valid!")
exit(1)
if block_cipher_mode == "ECB":
bcm = aes.ECB(AES)
elif block_cipher_mode == "CBC":
bcm = aes.CBC(AES, 16)
elif block_cipher_mode == "CTR":
bcm = aes.CTR(AES)
bcm.decipher(input_file, output_file)
def padding_oracle(data):
iv = data[:BLOCKSIZE]
ct = data[BLOCKSIZE:]
c = aes.CBC(KEY, iv)
try:
c.decrypt(ct)
return True
except ValueError:
return False
def test_challenge_10_cbc(self):
with open('10.txt') as f:
data = b64decode(f.read())
c = aes.CBC(KEY, b'\x00' * 16)
self.assertEqual(c.decrypt(data), PLAINTEXT)
def encrypt():
plain = random.choice(PLAINTEXTS)
iv = os.urandom(BLOCKSIZE)
c = aes.CBC(KEY, iv)
return iv + c.encrypt(pkcs7pad(plain, BLOCKSIZE))
def test_challenge_10_twoway(self):
e = aes.CBC(KEY, b'\x00' * 16)
d = aes.CBC(KEY, b'\x00' * 16)
x = e.encrypt(b"foobar" * 123)
self.assertEqual(d.decrypt(x), b'foobar' * 123)