add sign/verify ctx creation methods to RSABackend interface
diff --git a/cryptography/hazmat/backends/interfaces.py b/cryptography/hazmat/backends/interfaces.py
index b867f26..73f861a 100644
--- a/cryptography/hazmat/backends/interfaces.py
+++ b/cryptography/hazmat/backends/interfaces.py
@@ -90,3 +90,15 @@
Generate an RSAPrivateKey instance with public_exponent and a modulus
of key_size bits.
"""
+
+ @abc.abstractmethod
+ def create_rsa_sign_ctx(self, private_key, padding, algorithm):
+ """
+ Returns an object conforming to the AsymmetricSignContext interface.
+ """
+
+ @abc.abstractmethod
+ def create_rsa_verify_ctx(self, public_key, signature, padding, algorithm):
+ """
+ Returns an object conforming to the AsymmetricVerifyContext interface.
+ """