add missing DSABackend numbers loading methods to Multibackend

2 files changed, 30 insertions, 0 deletions

diff --git a/cryptography/hazmat/backends/multibackend.py b/cryptography/hazmat/backends/multibackend.py
index 35e2a093..6893cad6 100644
--- a/cryptography/hazmat/backends/multibackend.py
+++ b/cryptography/hazmat/backends/multibackend.py
@@ -239,6 +239,18 @@ class MultiBackend(object):
         raise UnsupportedAlgorithm("DSA is not supported by the backend.",
                                    _Reasons.UNSUPPORTED_PUBLIC_KEY_ALGORITHM)
 
+    def load_dsa_public_numbers(self, numbers):
+        for b in self._filtered_backends(DSABackend):
+            return b.load_dsa_public_numbers(numbers)
+        raise UnsupportedAlgorithm("DSA is not supported by the backend.",
+                                   _Reasons.UNSUPPORTED_PUBLIC_KEY_ALGORITHM)
+
+    def load_dsa_private_numbers(self, numbers):
+        for b in self._filtered_backends(DSABackend):
+            return b.load_dsa_private_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 de5f1fde..168ed688 100644
--- a/tests/hazmat/backends/test_multibackend.py
+++ b/tests/hazmat/backends/test_multibackend.py
@@ -144,6 +144,12 @@ class DummyDSABackend(object):
     def dsa_parameters_supported(self, p, q, g):
         pass
 
+    def load_dsa_private_numbers(self, numbers):
+        pass
+
+    def load_dsa_public_numbers(self, numbers):
+        pass
+
 
 @utils.register_interface(CMACBackend)
 class DummyCMACBackend(object):
@@ -365,6 +371,8 @@ class TestMultiBackend(object):
         backend.create_dsa_signature_ctx("private_key", hashes.SHA1())
         backend.dsa_hash_supported(hashes.SHA1())
         backend.dsa_parameters_supported(1, 2, 3)
+        backend.load_dsa_private_numbers("numbers")
+        backend.load_dsa_public_numbers("numbers")
 
         backend = MultiBackend([])
         with raises_unsupported_algorithm(
@@ -404,6 +412,16 @@ class TestMultiBackend(object):
         ):
             backend.dsa_parameters_supported('p', 'q', 'g')
 
+        with raises_unsupported_algorithm(
+            _Reasons.UNSUPPORTED_PUBLIC_KEY_ALGORITHM
+        ):
+            backend.load_dsa_private_numbers("numbers")
+
+        with raises_unsupported_algorithm(
+            _Reasons.UNSUPPORTED_PUBLIC_KEY_ALGORITHM
+        ):
+            backend.load_dsa_public_numbers("numbers")
+
     def test_cmac(self):
         backend = MultiBackend([
             DummyCMACBackend([algorithms.AES])