mirror of
https://github.com/thegeeklab/ansible-later.git
synced 2024-11-16 18:10:38 +00:00
68 lines
2.2 KiB
Python
68 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, UnsupportedAlgorithm, _Reasons
|
|
)
|
|
from cryptography.hazmat.backends.interfaces import HMACBackend
|
|
from cryptography.hazmat.primitives import hashes, mac
|
|
|
|
|
|
@utils.register_interface(mac.MACContext)
|
|
@utils.register_interface(hashes.HashContext)
|
|
class HMAC(object):
|
|
def __init__(self, key, algorithm, backend, ctx=None):
|
|
if not isinstance(backend, HMACBackend):
|
|
raise UnsupportedAlgorithm(
|
|
"Backend object does not implement HMACBackend.",
|
|
_Reasons.BACKEND_MISSING_INTERFACE
|
|
)
|
|
|
|
if not isinstance(algorithm, hashes.HashAlgorithm):
|
|
raise TypeError("Expected instance of hashes.HashAlgorithm.")
|
|
self._algorithm = algorithm
|
|
|
|
self._backend = backend
|
|
self._key = key
|
|
if ctx is None:
|
|
self._ctx = self._backend.create_hmac_ctx(key, self.algorithm)
|
|
else:
|
|
self._ctx = ctx
|
|
|
|
algorithm = utils.read_only_property("_algorithm")
|
|
|
|
def update(self, data):
|
|
if self._ctx is None:
|
|
raise AlreadyFinalized("Context was already finalized.")
|
|
utils._check_byteslike("data", data)
|
|
self._ctx.update(data)
|
|
|
|
def copy(self):
|
|
if self._ctx is None:
|
|
raise AlreadyFinalized("Context was already finalized.")
|
|
return HMAC(
|
|
self._key,
|
|
self.algorithm,
|
|
backend=self._backend,
|
|
ctx=self._ctx.copy()
|
|
)
|
|
|
|
def finalize(self):
|
|
if self._ctx is None:
|
|
raise AlreadyFinalized("Context was already finalized.")
|
|
digest = self._ctx.finalize()
|
|
self._ctx = None
|
|
return digest
|
|
|
|
def verify(self, signature):
|
|
utils._check_bytes("signature", signature)
|
|
if self._ctx is None:
|
|
raise AlreadyFinalized("Context was already finalized.")
|
|
|
|
ctx, self._ctx = self._ctx, None
|
|
ctx.verify(signature)
|