# 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 CMACBackend from cryptography.hazmat.primitives import ciphers, mac @utils.register_interface(mac.MACContext) class CMAC(object): def __init__(self, algorithm, backend, ctx=None): if not isinstance(backend, CMACBackend): raise UnsupportedAlgorithm( "Backend object does not implement CMACBackend.", _Reasons.BACKEND_MISSING_INTERFACE ) if not isinstance(algorithm, ciphers.BlockCipherAlgorithm): raise TypeError( "Expected instance of BlockCipherAlgorithm." ) self._algorithm = algorithm self._backend = backend if ctx is None: self._ctx = self._backend.create_cmac_ctx(self._algorithm) else: self._ctx = ctx def update(self, data): if self._ctx is None: raise AlreadyFinalized("Context was already finalized.") if not isinstance(data, bytes): raise TypeError("data must be bytes.") self._ctx.update(data) 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): if not isinstance(signature, bytes): raise TypeError("signature must be bytes.") if self._ctx is None: raise AlreadyFinalized("Context was already finalized.") ctx, self._ctx = self._ctx, None ctx.verify(signature) def copy(self): if self._ctx is None: raise AlreadyFinalized("Context was already finalized.") return CMAC( self._algorithm, backend=self._backend, ctx=self._ctx.copy() )
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__pycache__ | Folder | 0755 |
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asymmetric | Folder | 0755 |
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ciphers | Folder | 0755 |
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kdf | Folder | 0755 |
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twofactor | Folder | 0755 |
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__init__.py | File | 246 B | 0644 |
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cmac.py | File | 2.17 KB | 0644 |
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constant_time.py | File | 798 B | 0644 |
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hashes.py | File | 4.7 KB | 0644 |
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hmac.py | File | 2.28 KB | 0644 |
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keywrap.py | File | 3.19 KB | 0644 |
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mac.py | File | 884 B | 0644 |
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padding.py | File | 5.6 KB | 0644 |
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serialization.py | File | 5.38 KB | 0644 |
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