Merge pull request #153 from reaperhulk/hash-ctx-copy-api

When copying a hash, pass the api through to the new object

2 files changed, 23 insertions, 1 deletions

diff --git a/cryptography/primitives/hashes.py b/cryptography/primitives/hashes.py
index 7133a916..3aa52462 100644
--- a/cryptography/primitives/hashes.py
+++ b/cryptography/primitives/hashes.py
@@ -37,7 +37,7 @@ class BaseHash(six.with_metaclass(abc.ABCMeta)):
         self._api.update_hash_context(self._ctx, data)
 
     def copy(self):
-        return self.__class__(ctx=self._copy_ctx())
+        return self.__class__(api=self._api, ctx=self._copy_ctx())
 
     def digest(self):
         return self._api.finalize_hash_context(self._copy_ctx(),
diff --git a/tests/primitives/test_hashes.py b/tests/primitives/test_hashes.py
index 03de8916..46517701 100644
--- a/tests/primitives/test_hashes.py
+++ b/tests/primitives/test_hashes.py
@@ -13,10 +13,14 @@
 
 from __future__ import absolute_import, division, print_function
 
+import pretend
+
 import pytest
 
 import six
 
+from cryptography.bindings import _default_api
+
 from cryptography.primitives import hashes
 
 from .utils import generate_base_hash_test
@@ -33,6 +37,24 @@ class TestBaseHash(object):
         assert isinstance(m.hexdigest(), str)
 
 
+class TestCopyHash(object):
+    def test_copy_api_object(self):
+        pretend_api = pretend.stub(copy_hash_context=lambda a: "copiedctx")
+        pretend_ctx = pretend.stub()
+        h = hashes.SHA1(api=pretend_api, ctx=pretend_ctx)
+        assert h._api is pretend_api
+        assert h.copy()._api is h._api
+
+
+class TestDefaultAPISHA1(object):
+    def test_default_api_creation(self):
+        """
+        This test assumes the presence of SHA1 in the default API.
+        """
+        h = hashes.SHA1()
+        assert h._api is _default_api
+
+
 class TestSHA1(object):
     test_SHA1 = generate_base_hash_test(
         hashes.SHA1,