1 files changed, 86 insertions, 0 deletions
diff --git a/src/cryptography/hazmat/primitives/asymmetric/dsa.py b/src/cryptography/hazmat/primitives/asymmetric/dsa.py
index 9b06f3e6..58058df9 100644
--- a/src/cryptography/hazmat/primitives/asymmetric/dsa.py
+++ b/src/cryptography/hazmat/primitives/asymmetric/dsa.py
@@ -4,11 +4,97 @@
 
 from __future__ import absolute_import, division, print_function
 
+import abc
+
 import six
 
 from cryptography import utils
 
 
+@six.add_metaclass(abc.ABCMeta)
+class DSAParameters(object):
+    @abc.abstractmethod
+    def generate_private_key(self):
+        """
+        Generates and returns a DSAPrivateKey.
+        """
+
+
+@six.add_metaclass(abc.ABCMeta)
+class DSAParametersWithNumbers(DSAParameters):
+    @abc.abstractmethod
+    def parameter_numbers(self):
+        """
+        Returns a DSAParameterNumbers.
+        """
+
+
+@six.add_metaclass(abc.ABCMeta)
+class DSAPrivateKey(object):
+    @abc.abstractproperty
+    def key_size(self):
+        """
+        The bit length of the prime modulus.
+        """
+
+    @abc.abstractmethod
+    def public_key(self):
+        """
+        The DSAPublicKey associated with this private key.
+        """
+
+    @abc.abstractmethod
+    def parameters(self):
+        """
+        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):
+    @abc.abstractmethod
+    def private_numbers(self):
+        """
+        Returns a DSAPrivateNumbers.
+        """
+
+
+@six.add_metaclass(abc.ABCMeta)
+class DSAPublicKey(object):
+    @abc.abstractproperty
+    def key_size(self):
+        """
+        The bit length of the prime modulus.
+        """
+
+    @abc.abstractmethod
+    def parameters(self):
+        """
+        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):
+    @abc.abstractmethod
+    def public_numbers(self):
+        """
+        Returns a DSAPublicNumbers.
+        """
+
+
 def generate_parameters(key_size, backend):
     return backend.generate_dsa_parameters(key_size)