Raise UnsupportedAlgorithm when initing Hash()

Instead of just an AssertionError.

1 files changed, 12 insertions, 2 deletions

diff --git a/tests/hazmat/primitives/test_hashes.py b/tests/hazmat/primitives/test_hashes.py
index ff42e8f4..72bc3e27 100644
--- a/tests/hazmat/primitives/test_hashes.py
+++ b/tests/hazmat/primitives/test_hashes.py
@@ -19,12 +19,18 @@ import pytest
 
 import six
 
-from cryptography.exceptions import AlreadyFinalized
-from cryptography.hazmat.primitives import hashes
+from cryptography import utils
+from cryptography.exceptions import AlreadyFinalized, UnsupportedAlgorithm
+from cryptography.hazmat.primitives import hashes, interfaces
 
 from .utils import generate_base_hash_test
 
 
+@utils.register_interface(interfaces.HashAlgorithm)
+class UnsupportedDummyHash(object):
+    name = "unsupported-dummy-hash"
+
+
 class TestHashContext(object):
     def test_hash_reject_unicode(self, backend):
         m = hashes.Hash(hashes.SHA1(), backend=backend)
@@ -57,6 +63,10 @@ class TestHashContext(object):
         with pytest.raises(AlreadyFinalized):
             h.finalize()
 
+    def test_unsupported_hash(self, backend):
+        with pytest.raises(UnsupportedAlgorithm):
+            hashes.Hash(UnsupportedDummyHash(), backend)
+
 
 class TestSHA1(object):
     test_SHA1 = generate_base_hash_test(