31 lines
958 B
Python
31 lines
958 B
Python
"""Abstract class for AES."""
|
|
|
|
class AES:
|
|
def __init__(self, key, mode, IV, implementation):
|
|
if len(key) not in (16, 24, 32):
|
|
raise AssertionError()
|
|
if mode != 2:
|
|
raise AssertionError()
|
|
if len(IV) != 16:
|
|
raise AssertionError()
|
|
self.isBlockCipher = True
|
|
self.block_size = 16
|
|
self.implementation = implementation
|
|
if len(key)==16:
|
|
self.name = "aes128"
|
|
elif len(key)==24:
|
|
self.name = "aes192"
|
|
elif len(key)==32:
|
|
self.name = "aes256"
|
|
else:
|
|
raise AssertionError()
|
|
|
|
#CBC-Mode encryption, returns ciphertext
|
|
#WARNING: *MAY* modify the input as well
|
|
def encrypt(self, plaintext):
|
|
assert(len(plaintext) % 16 == 0)
|
|
|
|
#CBC-Mode decryption, returns plaintext
|
|
#WARNING: *MAY* modify the input as well
|
|
def decrypt(self, ciphertext):
|
|
assert(len(ciphertext) % 16 == 0) |