Merge pull request #1196 from reaperhulk/split-commoncrypto-backend-hashes

split commoncrypto backend - hashes

2 files changed, 63 insertions, 44 deletions

diff --git a/cryptography/hazmat/backends/commoncrypto/backend.py b/cryptography/hazmat/backends/commoncrypto/backend.py
index 41be11f9..77f1bf4d 100644
--- a/cryptography/hazmat/backends/commoncrypto/backend.py
+++ b/cryptography/hazmat/backends/commoncrypto/backend.py
@@ -19,6 +19,7 @@ from cryptography import utils
 from cryptography.exceptions import (
     InternalError, InvalidTag, UnsupportedAlgorithm, _Reasons
 )
+from cryptography.hazmat.backends.commoncrypto.hashes import _HashContext
 from cryptography.hazmat.backends.interfaces import (
     CipherBackend, HMACBackend, HashBackend, PBKDF2HMACBackend
 )
@@ -416,50 +417,6 @@ class _GCMCipherContext(object):
 
 
 @utils.register_interface(interfaces.HashContext)
-class _HashContext(object):
-    def __init__(self, backend, algorithm, ctx=None):
-        self.algorithm = algorithm
-        self._backend = backend
-
-        if ctx is None:
-            try:
-                methods = self._backend._hash_mapping[self.algorithm.name]
-            except KeyError:
-                raise UnsupportedAlgorithm(
-                    "{0} is not a supported hash on this backend.".format(
-                        algorithm.name),
-                    _Reasons.UNSUPPORTED_HASH
-                )
-            ctx = self._backend._ffi.new(methods.ctx)
-            res = methods.hash_init(ctx)
-            assert res == 1
-
-        self._ctx = ctx
-
-    def copy(self):
-        methods = self._backend._hash_mapping[self.algorithm.name]
-        new_ctx = self._backend._ffi.new(methods.ctx)
-        # CommonCrypto has no APIs for copying hashes, so we have to copy the
-        # underlying struct.
-        new_ctx[0] = self._ctx[0]
-
-        return _HashContext(self._backend, self.algorithm, ctx=new_ctx)
-
-    def update(self, data):
-        methods = self._backend._hash_mapping[self.algorithm.name]
-        res = methods.hash_update(self._ctx, data, len(data))
-        assert res == 1
-
-    def finalize(self):
-        methods = self._backend._hash_mapping[self.algorithm.name]
-        buf = self._backend._ffi.new("unsigned char[]",
-                                     self.algorithm.digest_size)
-        res = methods.hash_final(buf, self._ctx)
-        assert res == 1
-        return self._backend._ffi.buffer(buf)[:]
-
-
-@utils.register_interface(interfaces.HashContext)
 class _HMACContext(object):
     def __init__(self, backend, key, algorithm, ctx=None):
         self.algorithm = algorithm
diff --git a/cryptography/hazmat/backends/commoncrypto/hashes.py b/cryptography/hazmat/backends/commoncrypto/hashes.py
new file mode 100644
index 00000000..ebad7201
--- /dev/null
+++ b/cryptography/hazmat/backends/commoncrypto/hashes.py
@@ -0,0 +1,62 @@
+# 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 _HashContext(object):
+    def __init__(self, backend, algorithm, ctx=None):
+        self.algorithm = algorithm
+        self._backend = backend
+
+        if ctx is None:
+            try:
+                methods = self._backend._hash_mapping[self.algorithm.name]
+            except KeyError:
+                raise UnsupportedAlgorithm(
+                    "{0} is not a supported hash on this backend.".format(
+                        algorithm.name),
+                    _Reasons.UNSUPPORTED_HASH
+                )
+            ctx = self._backend._ffi.new(methods.ctx)
+            res = methods.hash_init(ctx)
+            assert res == 1
+
+        self._ctx = ctx
+
+    def copy(self):
+        methods = self._backend._hash_mapping[self.algorithm.name]
+        new_ctx = self._backend._ffi.new(methods.ctx)
+        # CommonCrypto has no APIs for copying hashes, so we have to copy the
+        # underlying struct.
+        new_ctx[0] = self._ctx[0]
+
+        return _HashContext(self._backend, self.algorithm, ctx=new_ctx)
+
+    def update(self, data):
+        methods = self._backend._hash_mapping[self.algorithm.name]
+        res = methods.hash_update(self._ctx, data, len(data))
+        assert res == 1
+
+    def finalize(self):
+        methods = self._backend._hash_mapping[self.algorithm.name]
+        buf = self._backend._ffi.new("unsigned char[]",
+                                     self.algorithm.digest_size)
+        res = methods.hash_final(buf, self._ctx)
+        assert res == 1
+        return self._backend._ffi.buffer(buf)[:]