# This file is dual licensed under the terms of the Apache License, Version
# 2.0, and the BSD License. See the LICENSE file in the root of this repository
# for complete details.
from __future__ import absolute_import, division, print_function
from cryptography import utils
from cryptography.hazmat.primitives.ciphers import (
BlockCipherAlgorithm,
CipherAlgorithm,
)
from cryptography.hazmat.primitives.ciphers.modes import ModeWithNonce
def _verify_key_size(algorithm, key):
# Verify that the key is instance of bytes
utils._check_byteslike("key", key)
# Verify that the key size matches the expected key size
if len(key) * 8 not in algorithm.key_sizes:
raise ValueError(
"Invalid key size ({}) for {}.".format(
len(key) * 8, algorithm.name
)
)
return key
[docs]@utils.register_interface(BlockCipherAlgorithm)
@utils.register_interface(CipherAlgorithm)
class AES(object):
name = "AES"
block_size = 128
# 512 added to support AES-256-XTS, which uses 512-bit keys
key_sizes = frozenset([128, 192, 256, 512])
def __init__(self, key):
self.key = _verify_key_size(self, key)
@property
def key_size(self):
return len(self.key) * 8
[docs]@utils.register_interface(BlockCipherAlgorithm)
@utils.register_interface(CipherAlgorithm)
class Camellia(object):
name = "camellia"
block_size = 128
key_sizes = frozenset([128, 192, 256])
def __init__(self, key):
self.key = _verify_key_size(self, key)
@property
def key_size(self):
return len(self.key) * 8
[docs]@utils.register_interface(BlockCipherAlgorithm)
@utils.register_interface(CipherAlgorithm)
class TripleDES(object):
name = "3DES"
block_size = 64
key_sizes = frozenset([64, 128, 192])
def __init__(self, key):
if len(key) == 8:
key += key + key
elif len(key) == 16:
key += key[:8]
self.key = _verify_key_size(self, key)
@property
def key_size(self):
return len(self.key) * 8
[docs]@utils.register_interface(BlockCipherAlgorithm)
@utils.register_interface(CipherAlgorithm)
class Blowfish(object):
name = "Blowfish"
block_size = 64
key_sizes = frozenset(range(32, 449, 8))
def __init__(self, key):
self.key = _verify_key_size(self, key)
@property
def key_size(self):
return len(self.key) * 8
[docs]@utils.register_interface(BlockCipherAlgorithm)
@utils.register_interface(CipherAlgorithm)
class CAST5(object):
name = "CAST5"
block_size = 64
key_sizes = frozenset(range(40, 129, 8))
def __init__(self, key):
self.key = _verify_key_size(self, key)
@property
def key_size(self):
return len(self.key) * 8
[docs]@utils.register_interface(CipherAlgorithm)
class ARC4(object):
name = "RC4"
key_sizes = frozenset([40, 56, 64, 80, 128, 160, 192, 256])
def __init__(self, key):
self.key = _verify_key_size(self, key)
@property
def key_size(self):
return len(self.key) * 8
[docs]@utils.register_interface(CipherAlgorithm)
class IDEA(object):
name = "IDEA"
block_size = 64
key_sizes = frozenset([128])
def __init__(self, key):
self.key = _verify_key_size(self, key)
@property
def key_size(self):
return len(self.key) * 8
[docs]@utils.register_interface(BlockCipherAlgorithm)
@utils.register_interface(CipherAlgorithm)
class SEED(object):
name = "SEED"
block_size = 128
key_sizes = frozenset([128])
def __init__(self, key):
self.key = _verify_key_size(self, key)
@property
def key_size(self):
return len(self.key) * 8
[docs]@utils.register_interface(CipherAlgorithm)
@utils.register_interface(ModeWithNonce)
class ChaCha20(object):
name = "ChaCha20"
key_sizes = frozenset([256])
def __init__(self, key, nonce):
self.key = _verify_key_size(self, key)
utils._check_byteslike("nonce", nonce)
if len(nonce) != 16:
raise ValueError("nonce must be 128-bits (16 bytes)")
self._nonce = nonce
nonce = utils.read_only_property("_nonce")
@property
def key_size(self):
return len(self.key) * 8