mirror of
https://github.com/PiBrewing/craftbeerpi4.git
synced 2024-12-25 15:04:56 +01:00
63 lines
2.2 KiB
Python
63 lines
2.2 KiB
Python
|
# 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.exceptions import (
|
||
|
|
AlreadyFinalized,
|
||
|
|
InvalidKey,
|
||
|
|
UnsupportedAlgorithm,
|
||
|
|
_Reasons,
|
||
|
|
)
|
||
|
|
from cryptography.hazmat.backends import _get_backend
|
||
|
|
from cryptography.hazmat.backends.interfaces import PBKDF2HMACBackend
|
||
|
|
from cryptography.hazmat.primitives import constant_time
|
||
|
|
from cryptography.hazmat.primitives.kdf import KeyDerivationFunction
|
||
|
|
|
||
|
|
|
||
|
|
@utils.register_interface(KeyDerivationFunction)
|
||
|
|
class PBKDF2HMAC(object):
|
||
|
|
def __init__(self, algorithm, length, salt, iterations, backend=None):
|
||
|
|
backend = _get_backend(backend)
|
||
|
|
if not isinstance(backend, PBKDF2HMACBackend):
|
||
|
|
raise UnsupportedAlgorithm(
|
||
|
|
"Backend object does not implement PBKDF2HMACBackend.",
|
||
|
|
_Reasons.BACKEND_MISSING_INTERFACE,
|
||
|
|
)
|
||
|
|
|
||
|
|
if not backend.pbkdf2_hmac_supported(algorithm):
|
||
|
|
raise UnsupportedAlgorithm(
|
||
|
|
"{} is not supported for PBKDF2 by this backend.".format(
|
||
|
|
algorithm.name
|
||
|
|
),
|
||
|
|
_Reasons.UNSUPPORTED_HASH,
|
||
|
|
)
|
||
|
|
self._used = False
|
||
|
|
self._algorithm = algorithm
|
||
|
|
self._length = length
|
||
|
|
utils._check_bytes("salt", salt)
|
||
|
|
self._salt = salt
|
||
|
|
self._iterations = iterations
|
||
|
|
self._backend = backend
|
||
|
|
|
||
|
|
def derive(self, key_material):
|
||
|
|
if self._used:
|
||
|
|
raise AlreadyFinalized("PBKDF2 instances can only be used once.")
|
||
|
|
self._used = True
|
||
|
|
|
||
|
|
utils._check_byteslike("key_material", key_material)
|
||
|
|
return self._backend.derive_pbkdf2_hmac(
|
||
|
|
self._algorithm,
|
||
|
|
self._length,
|
||
|
|
self._salt,
|
||
|
|
self._iterations,
|
||
|
|
key_material,
|
||
|
|
)
|
||
|
|
|
||
|
|
def verify(self, key_material, expected_key):
|
||
|
|
derived_key = self.derive(key_material)
|
||
|
|
if not constant_time.bytes_eq(derived_key, expected_key):
|
||
|
|
raise InvalidKey("Keys do not match.")
|