diff options
| -rw-r--r-- | cryptography/hazmat/backends/commoncrypto/backend.py | 64 | ||||
| -rw-r--r-- | tests/hazmat/backends/test_commoncrypto.py | 5 |
2 files changed, 33 insertions, 36 deletions
diff --git a/cryptography/hazmat/backends/commoncrypto/backend.py b/cryptography/hazmat/backends/commoncrypto/backend.py index 8b48fecc..a9ffba4e 100644 --- a/cryptography/hazmat/backends/commoncrypto/backend.py +++ b/cryptography/hazmat/backends/commoncrypto/backend.py @@ -120,36 +120,52 @@ class Backend(object): def create_symmetric_decryption_ctx(self, cipher, mode): return _CipherContext(self, cipher, mode, _CipherContext._DECRYPT) - def register_cipher_adapter(self, cipher_cls, mode_cls, adapter): + def register_cipher_adapter(self, cipher_cls, cipher_const, mode_cls, + mode_const): if (cipher_cls, mode_cls) in self._cipher_registry: raise ValueError("Duplicate registration for: {0} {1}".format( cipher_cls, mode_cls) ) - self._cipher_registry[cipher_cls, mode_cls] = adapter + self._cipher_registry[cipher_cls, mode_cls] = (cipher_const, + mode_const) def _register_default_ciphers(self): - for mode_cls in [CBC, ECB, CFB, OFB, CTR]: + for mode_cls, mode_const in [ + (CBC, self._lib.kCCModeCBC), (ECB, self._lib.kCCModeECB), + (CFB, self._lib.kCCModeCFB), (OFB, self._lib.kCCModeOFB), + (CTR, self._lib.kCCModeCTR) + ]: self.register_cipher_adapter( AES, + self._lib.kCCAlgorithmAES128, mode_cls, - _GetCipherModeEnum() + mode_const ) - for mode_cls in [CBC, CFB, OFB]: + for mode_cls, mode_const in [ + (CBC, self._lib.kCCModeCBC), (CFB, self._lib.kCCModeCFB), + (OFB, self._lib.kCCModeOFB), + ]: self.register_cipher_adapter( TripleDES, + self._lib.kCCAlgorithm3DES, mode_cls, - _GetCipherModeEnum() + mode_const ) - for mode_cls in [CBC, CFB, OFB, ECB]: + for mode_cls, mode_const in [ + (CBC, self._lib.kCCModeCBC), (ECB, self._lib.kCCModeECB), + (CFB, self._lib.kCCModeCFB), (OFB, self._lib.kCCModeOFB), + ]: self.register_cipher_adapter( Blowfish, + self._lib.kCCAlgorithmBlowfish, mode_cls, - _GetCipherModeEnum() + mode_const ) self.register_cipher_adapter( ARC4, + self._lib.kCCAlgorithmRC4, type(None), - _GetCipherModeEnum() + self._lib.kCCModeRC4 ) def _check_response(self, response): @@ -168,27 +184,6 @@ class Backend(object): ) -class _GetCipherModeEnum(object): - def __call__(self, backend, cipher, mode): - cipher_enum = { - AES: backend._lib.kCCAlgorithmAES128, - TripleDES: backend._lib.kCCAlgorithm3DES, - Blowfish: backend._lib.kCCAlgorithmBlowfish, - ARC4: backend._lib.kCCAlgorithmRC4, - }[type(cipher)] - - mode_enum = { - ECB: backend._lib.kCCModeECB, - CBC: backend._lib.kCCModeCBC, - CTR: backend._lib.kCCModeCTR, - CFB: backend._lib.kCCModeCFB, - OFB: backend._lib.kCCModeOFB, - type(None): backend._lib.kCCModeRC4, - }[type(mode)] - - return (cipher_enum, mode_enum) - - def _release_cipher_ctx(ctx): """ Called by the garbage collector and used to safely dereference and @@ -226,7 +221,7 @@ class _CipherContext(object): registry = self._backend._cipher_registry try: - adapter = registry[type(cipher), type(mode)] + cipher_enum, mode_enum = registry[type(cipher), type(mode)] except KeyError: raise UnsupportedAlgorithm( "cipher {0} in {1} mode is not supported " @@ -234,9 +229,8 @@ class _CipherContext(object): cipher.name, mode.name if mode else mode) ) - cipher_enum, mode_enum = adapter(self._backend, cipher, mode) ctx = self._backend._ffi.new("CCCryptorRef *") - ctx = self._backend._ffi.gc(ctx, self._release_cipher_ctx) + ctx = self._backend._ffi.gc(ctx, _release_cipher_ctx) if isinstance(mode, interfaces.ModeWithInitializationVector): iv_nonce = mode.initialization_vector @@ -284,8 +278,8 @@ class _CipherContext(object): res = self._backend._lib.CCCryptorFinal( self._ctx[0], buf, len(buf), outlen) self._backend._check_response(res) - res = self._backend._lib.CCCryptorRelease(self._ctx[0]) - self._backend._check_response(res) + # TODO: how do we release this here without causing a crash when + # the GC also releases it? return self._backend._ffi.buffer(buf)[:outlen[0]] diff --git a/tests/hazmat/backends/test_commoncrypto.py b/tests/hazmat/backends/test_commoncrypto.py index 8b353237..8022863c 100644 --- a/tests/hazmat/backends/test_commoncrypto.py +++ b/tests/hazmat/backends/test_commoncrypto.py @@ -28,7 +28,10 @@ class TestCommonCrypto(object): def test_register_duplicate_cipher_adapter(self): from cryptography.hazmat.backends.commoncrypto.backend import backend with pytest.raises(ValueError): - backend.register_cipher_adapter(AES, CBC, None) + backend.register_cipher_adapter( + AES, backend._lib.kCCAlgorithmAES128, + CBC, backend._lib.kCCModeCBC + ) def test_handle_response(self): from cryptography.hazmat.backends.commoncrypto.backend import backend |