Added more copy() tests

2 files changed, 9 insertions, 3 deletions

diff --git a/cryptography/hazmat/backends/openssl/backend.py b/cryptography/hazmat/backends/openssl/backend.py
index 4137ad10..7d73c413 100644
--- a/cryptography/hazmat/backends/openssl/backend.py
+++ b/cryptography/hazmat/backends/openssl/backend.py
@@ -1309,16 +1309,15 @@ class _CMACContext(object):
 
     def copy(self):
         copied_ctx = self._backend._lib.CMAC_CTX_new()
-        self._backend._lib.CMAC_CTX_init(copied_ctx)
         copied_ctx = self._backend._ffi.gc(
             copied_ctx, self._backend._lib.CMAC_CTX_free
         )
         res = self._backend._lib.CMAC_CTX_copy(
             copied_ctx, self._ctx
         )
-        assert res == 0
+        assert res == 1
         return _CMACContext(
-            self._backend, self.algorithm, ctx=copied_ctx
+            self._backend, self._algorithm, ctx=copied_ctx
         )
 
 
diff --git a/tests/hazmat/primitives/test_cmac.py b/tests/hazmat/primitives/test_cmac.py
index 25568114..f47f2c13 100644
--- a/tests/hazmat/primitives/test_cmac.py
+++ b/tests/hazmat/primitives/test_cmac.py
@@ -181,6 +181,13 @@ class TestCMAC(object):
         with pytest.raises(TypeError):
             cmac.verify(six.u(''))
 
+    def test_copy_with_backend(self, backend):
+        key = b"2b7e151628aed2a6abf7158809cf4f3c"
+        cmac = CMAC(AES(key), backend)
+        cmac.update(b"6bc1bee22e409f96e93d7e117393172a")
+        copy_cmac = cmac.copy()
+        assert cmac.finalize() == copy_cmac.finalize()
+
 
 def test_copy():
     @utils.register_interface(CMACBackend)