Merge pull request #719 from skeuomorf/master

Add DSA interfaces

2 files changed, 200 insertions, 0 deletions

diff --git a/cryptography/hazmat/primitives/interfaces.py b/cryptography/hazmat/primitives/interfaces.py
index 11696160..3824bcde 100644
--- a/cryptography/hazmat/primitives/interfaces.py
+++ b/cryptography/hazmat/primitives/interfaces.py
@@ -287,6 +287,98 @@ class RSAPublicKey(six.with_metaclass(abc.ABCMeta)):
         """
 
 
+class DSAParameters(six.with_metaclass(abc.ABCMeta)):
+    @abc.abstractproperty
+    def modulus(self):
+        """
+        The prime modulus that's used in generating the DSA keypair and used
+        in the DSA signing and verification processes.
+        """
+
+    @abc.abstractproperty
+    def subgroup_order(self):
+        """
+        The subgroup order that's used in generating the DSA keypair
+        by the generator and used in the DSA signing and verification
+        processes.
+        """
+
+    @abc.abstractproperty
+    def generator(self):
+        """
+        The generator that is used in generating the DSA keypair and used
+        in the DSA signing and verification processes.
+        """
+
+    @abc.abstractproperty
+    def p(self):
+        """
+        The prime modulus that's used in generating the DSA keypair and used
+        in the DSA signing and verification processes. Alias for modulus.
+        """
+
+    @abc.abstractproperty
+    def q(self):
+        """
+        The subgroup order that's used in generating the DSA keypair
+        by the generator and used in the DSA signing and verification
+        processes. Alias for subgroup_order.
+        """
+
+    @abc.abstractproperty
+    def g(self):
+        """
+        The generator that is used in generating the DSA keypair and used
+        in the DSA signing and verification processes. Alias for generator.
+        """
+
+
+class DSAPrivateKey(six.with_metaclass(abc.ABCMeta)):
+    @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.abstractproperty
+    def x(self):
+        """
+        The private key "x" in the DSA structure.
+        """
+
+    @abc.abstractproperty
+    def y(self):
+        """
+        The public key.
+        """
+
+    @abc.abstractmethod
+    def parameters(self):
+        """
+        The DSAParameters object associated with this private key.
+        """
+
+
+class DSAPublicKey(six.with_metaclass(abc.ABCMeta)):
+    @abc.abstractproperty
+    def y(self):
+        """
+        The public key.
+        """
+
+    @abc.abstractmethod
+    def parameters(self):
+        """
+        The DSAParameters object associated with this public key.
+        """
+
+
 class AsymmetricSignatureContext(six.with_metaclass(abc.ABCMeta)):
     @abc.abstractmethod
     def update(self, data):
diff --git a/docs/hazmat/primitives/interfaces.rst b/docs/hazmat/primitives/interfaces.rst
index 15ad1d1b..cc2a3000 100644
--- a/docs/hazmat/primitives/interfaces.rst
+++ b/docs/hazmat/primitives/interfaces.rst
@@ -231,6 +231,113 @@ Asymmetric Interfaces
         The public exponent. Alias for :attr:`public_exponent`.
 
 
+.. class:: DSAParameters
+
+    .. versionadded:: 0.3
+
+    `DSA`_ parameters.
+
+    .. attribute:: modulus
+
+        :type: int
+
+        The prime modulus that is used in generating the DSA key pair and used
+        in the DSA signing and verification processes.
+
+    .. attribute:: subgroup_order
+
+        :type: int
+
+        The subgroup order that is used in generating the DSA key pair
+        by the generator and used in the DSA signing and verification
+        processes.
+
+    .. attribute:: generator
+
+        :type: int
+
+        The generator that is used in generating the DSA key pair and used
+        in the DSA signing and verification processes.
+
+    .. attribute:: p
+
+        :type: int
+
+        The prime modulus that is used in generating the DSA key pair and used
+        in the DSA signing and verification processes. Alias for :attr:`modulus`.
+
+    .. attribute:: q
+
+        :type: int
+
+        The subgroup order that is used in generating the DSA key pair
+        by the generator and used in the DSA signing and verification
+        processes. Alias for :attr:`subgroup_order`.
+
+    .. attribute:: g
+
+        :type: int
+
+        The generator that is used in generating the DSA key pair and used
+        in the DSA signing and verification processes. Alias for :attr:`generator`.
+
+
+.. class:: DSAPrivateKey
+
+    .. versionadded:: 0.3
+
+    A `DSA`_ private key.
+
+    .. method:: public_key()
+
+        :return: :class:`~cryptography.hazmat.primitives.interfaces.DSAPublicKey`
+
+        An DSA public key object corresponding to the values of the private key.
+
+    .. method:: parameters()
+
+        :return: :class:`~cryptography.hazmat.primitives.interfaces.DSAParameters`
+
+        The DSAParameters object associated with this private key.
+
+    .. attribute:: key_size
+
+        :type: int
+
+        The bit length of the modulus.
+
+    .. attribute:: x
+
+        :type: int
+
+        The private key.
+
+    .. attribute:: y
+
+        :type: int
+
+        The public key.
+
+
+.. class:: DSAPublicKey
+
+    .. versionadded:: 0.3
+
+    A `DSA`_ private key.
+
+    .. method:: parameters()
+
+        :return: :class:`~cryptography.hazmat.primitives.interfaces.DSAParameters`
+
+        The DSAParameters object associated with this public key.
+
+    .. attribute:: y
+
+        :type: int
+
+        The public key.
+
+
 .. class:: AsymmetricSignatureContext
 
     .. versionadded:: 0.2
@@ -335,3 +442,4 @@ Key Derivation Functions
 
 .. _`RSA`: https://en.wikipedia.org/wiki/RSA_(cryptosystem)
 .. _`Chinese remainder theorem`: https://en.wikipedia.org/wiki/Chinese_remainder_theorem
+.. _`DSA`: https://en.wikipedia.org/wiki/Digital_Signature_Algorithm