One shot sign/verify DSA (#3003)

* Add sign and verify methods to DSA

* Documented DSA sign/verify methods

* Added CHANGELOG entry

1 files changed, 20 insertions, 0 deletions

diff --git a/tests/hazmat/primitives/test_dsa.py b/tests/hazmat/primitives/test_dsa.py
index 46c86d54..dde60607 100644
--- a/tests/hazmat/primitives/test_dsa.py
+++ b/tests/hazmat/primitives/test_dsa.py
@@ -606,6 +606,16 @@ class TestDSAVerification(object):
         with pytest.raises(AlreadyFinalized):
             verifier.update(b"more data")
 
+    def test_verify(self, backend):
+        message = b"one little message"
+        algorithm = hashes.SHA1()
+        private_key = DSA_KEY_1024.private_key(backend)
+        signer = private_key.signer(algorithm)
+        signer.update(message)
+        signature = signer.finalize()
+        public_key = private_key.public_key()
+        public_key.verify(signature, message, algorithm)
+
 
 @pytest.mark.requires_backend_interface(interface=DSABackend)
 class TestDSASignature(object):
@@ -661,6 +671,16 @@ class TestDSASignature(object):
         with pytest.raises(AlreadyFinalized):
             signer.update(b"more data")
 
+    def test_sign(self, backend):
+        private_key = DSA_KEY_1024.private_key(backend)
+        message = b"one little message"
+        algorithm = hashes.SHA1()
+        signature = private_key.sign(message, algorithm)
+        public_key = private_key.public_key()
+        verifier = public_key.verifier(signature, algorithm)
+        verifier.update(message)
+        verifier.verify()
+
 
 class TestDSANumbers(object):
     def test_dsa_parameter_numbers(self):