add docs for sign/verify ctx creation interface
diff --git a/docs/hazmat/backends/interfaces.rst b/docs/hazmat/backends/interfaces.rst
index e6bf8f6..72b6491 100644
--- a/docs/hazmat/backends/interfaces.rst
+++ b/docs/hazmat/backends/interfaces.rst
@@ -212,3 +212,39 @@
provider.
:raises ValueError: If the public_exponent is not valid.
+
+ .. method:: create_rsa_sign_ctx(private_key, padding, algorithm)
+
+ :param private_key: An instance of a
+ :class:`~cryptography.hazmat.primitives.interfaces.RSAPrivateKey`
+ provider.
+
+ :param padding: An instance of a
+ :class:`~cryptography.hazmat.primitives.interfaces.AsymmetricPadding`
+ provider.
+
+ :param algorithm: An instance of a
+ :class:`~cryptography.hazmat.primitives.interfaces.HashAlgorithm`
+ provider.
+
+ :returns:
+ :class:`~cryptography.hazmat.primitives.interfaces.AsymmetricSignContext`
+
+ .. method:: create_rsa_verify_ctx(public_key, signature, padding, algorithm)
+
+ :param public_key: An instance of a
+ :class:`~cryptography.hazmat.primitives.interfaces.RSAPublicKey`
+ provider.
+
+ :param bytes signature: The signature to verify.
+
+ :param padding: An instance of a
+ :class:`~cryptography.hazmat.primitives.interfaces.AsymmetricPadding`
+ provider.
+
+ :param algorithm: An instance of a
+ :class:`~cryptography.hazmat.primitives.interfaces.HashAlgorithm`
+ provider.
+
+ :returns:
+ :class:`~cryptography.hazmat.primitives.interfaces.AsymmetricVerifyContext`