add missing signer/verifier to DSAPublicKey and DSAPrivateKey ifaces

These were present in the docs and the OpenSSL provider, but not
properly listed on the interface

1 files changed, 12 insertions, 0 deletions

diff --git a/cryptography/hazmat/primitives/interfaces.py b/cryptography/hazmat/primitives/interfaces.py
index c7ad0cf8..6ae0a4c5 100644
--- a/cryptography/hazmat/primitives/interfaces.py
+++ b/cryptography/hazmat/primitives/interfaces.py
@@ -287,6 +287,12 @@ class DSAPrivateKey(object):
         The DSAParameters object associated with this private key.
         """
 
+    @abc.abstractmethod
+    def signer(self, signature_algorithm):
+        """
+        Returns an AsymmetricSignatureContext used for signing data.
+        """
+
 
 @six.add_metaclass(abc.ABCMeta)
 class DSAPrivateKeyWithNumbers(DSAPrivateKey):
@@ -311,6 +317,12 @@ class DSAPublicKey(object):
         The DSAParameters object associated with this public key.
         """
 
+    @abc.abstractmethod
+    def verifier(self, signature, signature_algorithm):
+        """
+        Returns an AsymmetricVerificationContext used for signing data.
+        """
+
 
 @six.add_metaclass(abc.ABCMeta)
 class DSAPublicKeyWithNumbers(DSAPublicKey):