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Support for memoryview for SIV

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This commit is contained in:
Helder Eijs 2018-04-03 15:26:10 +02:00
parent 53be0708d7
commit 6fd65d491f
3 changed files with 104 additions and 41 deletions
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13
lib/Crypto/Cipher/_mode_siv.py
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@ -36,7 +36,7 @@ __all__ = ['SivMode']
from binascii import hexlify
from Crypto.Util.py3compat import byte_string, bord, unhexlify, b, bstr
from Crypto.Util.py3compat import byte_string, bord, unhexlify, _copy_bytes
from Crypto.Util.number import long_to_bytes, bytes_to_long
from Crypto.Protocol.KDF import _S2V
@ -93,7 +93,6 @@ class SivMode(object):
self._factory = factory
self._nonce = nonce
self._cipher_params = kwargs
if len(key) not in (32, 48, 64):
@ -106,7 +105,7 @@ class SivMode(object):
if len(nonce) == 0:
raise ValueError("When provided, the nonce must be non-empty")
self.nonce = bstr(nonce)
self.nonce = _copy_bytes(None, None, nonce)
"""Public attribute is only available in case of non-deterministic
encryption."""
@ -128,12 +127,12 @@ class SivMode(object):
def _create_ctr_cipher(self, mac_tag):
"""Create a new CTR cipher from the MAC in SIV mode"""
tag_int = bytes_to_long(bstr(mac_tag))
tag_int = bytes_to_long(mac_tag)
return self._factory.new(
self._subkey_cipher,
self._factory.MODE_CTR,
initial_value=tag_int ^ (tag_int & 0x8000000080000000L),
nonce=b(""),
nonce=b"",
**self._cipher_params)
def update(self, component):
@ -200,7 +199,7 @@ class SivMode(object):
self._next = [self.digest]
if self._nonce:
if hasattr(self, 'nonce'):
self._kdf.update(self.nonce)
self._kdf.update(plaintext)
@ -347,7 +346,7 @@ class SivMode(object):
plaintext = self._cipher.decrypt(ciphertext)
if self._nonce:
if hasattr(self, 'nonce'):
self._kdf.update(self.nonce)
if plaintext:
self._kdf.update(plaintext)