Document which backends implement which itnerfaces. Fixes #538
diff --git a/docs/hazmat/backends/interfaces.rst b/docs/hazmat/backends/interfaces.rst
index 49e4c88..5131ca1 100644
--- a/docs/hazmat/backends/interfaces.rst
+++ b/docs/hazmat/backends/interfaces.rst
@@ -19,6 +19,11 @@
A backend which provides methods for using ciphers for encryption
and decryption.
+ The following backends implement this interface:
+
+ * :doc:`/hazmat/backends/openssl`
+ * :doc:`/hazmat/backends/commoncrypto`
+
.. method:: cipher_supported(cipher, mode)
Check if a ``cipher`` and ``mode`` combination is supported by
@@ -76,6 +81,11 @@
A backend with methods for using cryptographic hash functions.
+ The following backends implement this interface:
+
+ * :doc:`/hazmat/backends/openssl`
+ * :doc:`/hazmat/backends/commoncrypto`
+
.. method:: hash_supported(algorithm)
Check if the specified ``algorithm`` is supported by this backend.
@@ -107,6 +117,11 @@
A backend with methods for using cryptographic hash functions as message
authentication codes.
+ The following backends implement this interface:
+
+ * :doc:`/hazmat/backends/openssl`
+ * :doc:`/hazmat/backends/commoncrypto`
+
.. method:: hmac_supported(algorithm)
Check if the specified ``algorithm`` is supported by this backend.
@@ -139,6 +154,11 @@
A backend with methods for using PBKDF2 using HMAC as a PRF.
+ The following backends implement this interface:
+
+ * :doc:`/hazmat/backends/openssl`
+ * :doc:`/hazmat/backends/commoncrypto`
+
.. method:: pbkdf2_hmac_supported(algorithm)
Check if the specified ``algorithm`` is supported by this backend.
@@ -171,4 +191,3 @@
the derived key. This is typically a password.
:return bytes: Derived key.
-