3 files changed, 34 insertions, 20 deletions
diff --git a/cryptography/hazmat/backends/interfaces.py b/cryptography/hazmat/backends/interfaces.py
index 19d6fb70..524e0a5b 100644
--- a/cryptography/hazmat/backends/interfaces.py
+++ b/cryptography/hazmat/backends/interfaces.py
@@ -142,11 +142,18 @@ class RSABackend(object):
         generation.
         """
 
-    def load_rsa_numbers(self, numbers):
+    @abc.abstractmethod
+    def load_rsa_private_numbers(self, numbers):
         """
         Returns an RSAPrivateKey provider.
         """
 
+    @abc.abstractmethod
+    def load_rsa_public_numbers(self, numbers):
+        """
+        Returns an RSAPublicKey provider.
+        """
+
 
 @six.add_metaclass(abc.ABCMeta)
 class DSABackend(object):
diff --git a/cryptography/hazmat/backends/multibackend.py b/cryptography/hazmat/backends/multibackend.py
index 5acec333..f3c79376 100644
--- a/cryptography/hazmat/backends/multibackend.py
+++ b/cryptography/hazmat/backends/multibackend.py
@@ -178,9 +178,16 @@ class MultiBackend(object):
         raise UnsupportedAlgorithm("RSA is not supported by the backend.",
                                    _Reasons.UNSUPPORTED_PUBLIC_KEY_ALGORITHM)
 
-    def load_rsa_numbers(self, numbers):
+    def load_rsa_private_numbers(self, numbers):
         for b in self._filtered_backends(RSABackend):
-            return b.load_rsa_numbers(numbers)
+            return b.load_rsa_private_numbers(numbers)
+
+        raise UnsupportedAlgorithm("RSA is not supported by the backend",
+                                   _Reasons.UNSUPPORTED_PUBLIC_KEY_ALGORITHM)
+
+    def load_rsa_public_numbers(self, numbers):
+        for b in self._filtered_backends(RSABackend):
+            return b.load_rsa_public_numbers(numbers)
 
         raise UnsupportedAlgorithm("RSA is not supported by the backend",
                                    _Reasons.UNSUPPORTED_PUBLIC_KEY_ALGORITHM)
diff --git a/cryptography/hazmat/backends/openssl/backend.py b/cryptography/hazmat/backends/openssl/backend.py
index e5870f3e..ffe09663 100644
--- a/cryptography/hazmat/backends/openssl/backend.py
+++ b/cryptography/hazmat/backends/openssl/backend.py
@@ -377,23 +377,23 @@ class Backend(object):
         return (public_exponent >= 3 and public_exponent & 1 != 0 and
                 key_size >= 512)
 
-    def load_rsa_numbers(self, numbers):
-        if isinstance(numbers, rsa.RSAPublicNumbers):
-            return rsa.RSAPublicKey(
-                public_exponent=numbers.e,
-                modulus=numbers.n
-            )
-        elif isinstance(numbers, rsa.RSAPrivateNumbers):
-            return rsa.RSAPrivateKey(
-                p=numbers.p,
-                q=numbers.q,
-                private_exponent=numbers.d,
-                dmp1=numbers.dmp1,
-                dmq1=numbers.dmq1,
-                iqmp=numbers.iqmp,
-                public_exponent=numbers.public_numbers.e,
-                modulus=numbers.public_numbers.n
-            )
+    def load_rsa_private_numbers(self, numbers):
+        return rsa.RSAPrivateKey(
+            p=numbers.p,
+            q=numbers.q,
+            private_exponent=numbers.d,
+            dmp1=numbers.dmp1,
+            dmq1=numbers.dmq1,
+            iqmp=numbers.iqmp,
+            public_exponent=numbers.public_numbers.e,
+            modulus=numbers.public_numbers.n
+        )
+
+    def load_rsa_public_numbers(self, numbers):
+        return rsa.RSAPublicKey(
+            public_exponent=numbers.e,
+            modulus=numbers.n
+        )
 
     def _new_evp_pkey(self):
         evp_pkey = self._lib.EVP_PKEY_new()