add ECB support to create_block_cipher_context

* This is a basic refactor to support ECB and CBC mode in this method.
  We can use this as a starting point to discuss a better solution.

1 files changed, 6 insertions, 0 deletions

diff --git a/tests/bindings/test_openssl.py b/tests/bindings/test_openssl.py
index 1579f002..e4b73460 100644
--- a/tests/bindings/test_openssl.py
+++ b/tests/bindings/test_openssl.py
@@ -11,6 +11,8 @@
 # See the License for the specific language governing permissions and
 # limitations under the License.
 
+import pytest
+
 from cryptography.bindings.openssl import api
 
 
@@ -28,3 +30,7 @@ class TestOpenSSL(object):
         for every OpenSSL.
         """
         assert api.openssl_version_text().startswith("OpenSSL")
+
+    def test_get_iv_invalid_mode(self):
+        with pytest.raises(NotImplementedError):
+            api._get_iv(None)