split commoncrypto backend - hmac
diff --git a/cryptography/hazmat/backends/commoncrypto/backend.py b/cryptography/hazmat/backends/commoncrypto/backend.py
index d22db1d..6147a99 100644
--- a/cryptography/hazmat/backends/commoncrypto/backend.py
+++ b/cryptography/hazmat/backends/commoncrypto/backend.py
@@ -20,6 +20,7 @@
InternalError, InvalidTag, UnsupportedAlgorithm, _Reasons
)
from cryptography.hazmat.backends.commoncrypto.hashes import _HashContext
+from cryptography.hazmat.backends.commoncrypto.hmac import _HMACContext
from cryptography.hazmat.backends.interfaces import (
CipherBackend, HMACBackend, HashBackend, PBKDF2HMACBackend
)
@@ -416,44 +417,4 @@
return self._tag
-@utils.register_interface(interfaces.HashContext)
-class _HMACContext(object):
- def __init__(self, backend, key, algorithm, ctx=None):
- self.algorithm = algorithm
- self._backend = backend
- if ctx is None:
- ctx = self._backend._ffi.new("CCHmacContext *")
- try:
- alg = self._backend._supported_hmac_algorithms[algorithm.name]
- except KeyError:
- raise UnsupportedAlgorithm(
- "{0} is not a supported HMAC hash on this backend.".format(
- algorithm.name),
- _Reasons.UNSUPPORTED_HASH
- )
-
- self._backend._lib.CCHmacInit(ctx, alg, key, len(key))
-
- self._ctx = ctx
- self._key = key
-
- def copy(self):
- copied_ctx = self._backend._ffi.new("CCHmacContext *")
- # CommonCrypto has no APIs for copying HMACs, so we have to copy the
- # underlying struct.
- copied_ctx[0] = self._ctx[0]
- return _HMACContext(
- self._backend, self._key, self.algorithm, ctx=copied_ctx
- )
-
- def update(self, data):
- self._backend._lib.CCHmacUpdate(self._ctx, data, len(data))
-
- def finalize(self):
- buf = self._backend._ffi.new("unsigned char[]",
- self.algorithm.digest_size)
- self._backend._lib.CCHmacFinal(self._ctx, buf)
- return self._backend._ffi.buffer(buf)[:]
-
-
backend = Backend()
diff --git a/cryptography/hazmat/backends/commoncrypto/hmac.py b/cryptography/hazmat/backends/commoncrypto/hmac.py
new file mode 100644
index 0000000..ec3a878
--- /dev/null
+++ b/cryptography/hazmat/backends/commoncrypto/hmac.py
@@ -0,0 +1,58 @@
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+# http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or
+# implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+
+from __future__ import absolute_import, division, print_function
+
+from cryptography import utils
+from cryptography.exceptions import UnsupportedAlgorithm, _Reasons
+from cryptography.hazmat.primitives import interfaces
+
+
+@utils.register_interface(interfaces.HashContext)
+class _HMACContext(object):
+ def __init__(self, backend, key, algorithm, ctx=None):
+ self.algorithm = algorithm
+ self._backend = backend
+ if ctx is None:
+ ctx = self._backend._ffi.new("CCHmacContext *")
+ try:
+ alg = self._backend._supported_hmac_algorithms[algorithm.name]
+ except KeyError:
+ raise UnsupportedAlgorithm(
+ "{0} is not a supported HMAC hash on this backend.".format(
+ algorithm.name),
+ _Reasons.UNSUPPORTED_HASH
+ )
+
+ self._backend._lib.CCHmacInit(ctx, alg, key, len(key))
+
+ self._ctx = ctx
+ self._key = key
+
+ def copy(self):
+ copied_ctx = self._backend._ffi.new("CCHmacContext *")
+ # CommonCrypto has no APIs for copying HMACs, so we have to copy the
+ # underlying struct.
+ copied_ctx[0] = self._ctx[0]
+ return _HMACContext(
+ self._backend, self._key, self.algorithm, ctx=copied_ctx
+ )
+
+ def update(self, data):
+ self._backend._lib.CCHmacUpdate(self._ctx, data, len(data))
+
+ def finalize(self):
+ buf = self._backend._ffi.new("unsigned char[]",
+ self.algorithm.digest_size)
+ self._backend._lib.CCHmacFinal(self._ctx, buf)
+ return self._backend._ffi.buffer(buf)[:]