Add DSA verification docs
diff --git a/docs/hazmat/backends/interfaces.rst b/docs/hazmat/backends/interfaces.rst
index 2f63f3e..e0937f9 100644
--- a/docs/hazmat/backends/interfaces.rst
+++ b/docs/hazmat/backends/interfaces.rst
@@ -345,6 +345,38 @@
1.0.0 and the key size is larger than 1024; older OpenSSL versions
do not support keys larger than 1024 bits.
+ .. method:: create_dsa_verification_ctx(public_key, signature, algorithm)
+
+ :param public_key: An instance of a
+ :class:`~cryptography.hazmat.primitives.interfaces.DSAPublicKey`
+ provider.
+
+ :param bytes signature: The signature to verify.
+
+ :param algorithm: An instance of a
+ :class:`~cryptography.hazmat.primitives.interfaces.HashAlgorithm`
+ provider.
+
+ :returns:
+ :class:`~cryptography.hazmat.primitives.interfaces.AsymmetricVerificationContext`
+
+ .. method:: dsa_signature_from_components(r, s)
+
+ :param int r: The r value which is part of a DSA signature.
+
+ :param int s: The s value which is part of a DSA signature.
+
+ :returns: A DSA signature in DER format.
+
+ .. method:: dsa_hash_supported(algorithm):
+
+ :param algorithm: An instance of a
+ :class:`~cryptography.hazmat.primitives.interfaces.HashAlgorithm`
+ provider.
+
+ :returns: ``True`` if the specified ``algorithm`` is supported by this
+ backend, otherwise ``False``.
+
.. class:: CMACBackend
diff --git a/docs/hazmat/backends/openssl.rst b/docs/hazmat/backends/openssl.rst
index 43e5d8f..f15bc28 100644
--- a/docs/hazmat/backends/openssl.rst
+++ b/docs/hazmat/backends/openssl.rst
@@ -14,6 +14,7 @@
It implements the following interfaces:
* :class:`~cryptography.hazmat.backends.interfaces.CipherBackend`
+ * :class:`~cryptography.hazmat.backends.interfaces.DSABackend`
* :class:`~cryptography.hazmat.backends.interfaces.HashBackend`
* :class:`~cryptography.hazmat.backends.interfaces.HMACBackend`
* :class:`~cryptography.hazmat.backends.interfaces.PBKDF2HMACBackend`