Merge pull request #1425 from reaperhulk/fix-missing-method

add load_dsa_parameter_numbers on multibackend

2 files changed, 15 insertions, 0 deletions

diff --git a/cryptography/hazmat/backends/multibackend.py b/cryptography/hazmat/backends/multibackend.py
index db189787..e873f504 100644
--- a/cryptography/hazmat/backends/multibackend.py
+++ b/cryptography/hazmat/backends/multibackend.py
@@ -210,6 +210,12 @@ class MultiBackend(object):
         raise UnsupportedAlgorithm("DSA is not supported by the backend.",
                                    _Reasons.UNSUPPORTED_PUBLIC_KEY_ALGORITHM)
 
+    def load_dsa_parameter_numbers(self, numbers):
+        for b in self._filtered_backends(DSABackend):
+            return b.load_dsa_parameter_numbers(numbers)
+        raise UnsupportedAlgorithm("DSA is not supported by the backend.",
+                                   _Reasons.UNSUPPORTED_PUBLIC_KEY_ALGORITHM)
+
     def cmac_algorithm_supported(self, algorithm):
         return any(
             b.cmac_algorithm_supported(algorithm)
diff --git a/tests/hazmat/backends/test_multibackend.py b/tests/hazmat/backends/test_multibackend.py
index 93934ad6..c50b6cf6 100644
--- a/tests/hazmat/backends/test_multibackend.py
+++ b/tests/hazmat/backends/test_multibackend.py
@@ -131,6 +131,9 @@ class DummyDSABackend(object):
     def load_dsa_public_numbers(self, numbers):
         pass
 
+    def load_dsa_parameter_numbers(self, numbers):
+        pass
+
 
 @utils.register_interface(CMACBackend)
 class DummyCMACBackend(object):
@@ -330,6 +333,7 @@ class TestMultiBackend(object):
         backend.dsa_parameters_supported(1, 2, 3)
         backend.load_dsa_private_numbers("numbers")
         backend.load_dsa_public_numbers("numbers")
+        backend.load_dsa_parameter_numbers("numbers")
 
         backend = MultiBackend([])
         with raises_unsupported_algorithm(
@@ -367,6 +371,11 @@ class TestMultiBackend(object):
         ):
             backend.load_dsa_public_numbers("numbers")
 
+        with raises_unsupported_algorithm(
+            _Reasons.UNSUPPORTED_PUBLIC_KEY_ALGORITHM
+        ):
+            backend.load_dsa_parameter_numbers("numbers")
+
     def test_cmac(self):
         backend = MultiBackend([
             DummyCMACBackend([algorithms.AES])