# Author: Trevor Perrin
# See the LICENSE file for legal information regarding use of this file.
"""Abstract class for AES."""
[docs]
class AES(object):
[docs]
def __init__(self, key, mode, IV, implementation):
if len(key) not in (16, 24, 32):
raise AssertionError()
if mode not in [2, 6]:
raise AssertionError()
if mode == 2:
if len(IV) != 16:
raise AssertionError()
if mode == 6:
if len(IV) > 16:
raise AssertionError()
self.isBlockCipher = True
self.isAEAD = False
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
[docs]
def encrypt(self, plaintext):
assert(len(plaintext) % 16 == 0)
#CBC-Mode decryption, returns plaintext
#WARNING: *MAY* modify the input as well
[docs]
def decrypt(self, ciphertext):
assert(len(ciphertext) % 16 == 0)