Merge branch 'master' into fernet

3 files changed, 145 insertions, 2 deletions

diff --git a/docs/cryptography-docs.py b/docs/cryptography-docs.py
index 4ed5526a..ea7e8eef 100644
--- a/docs/cryptography-docs.py
+++ b/docs/cryptography-docs.py
@@ -31,10 +31,14 @@ class Hazmat(nodes.Admonition, nodes.Element):
     pass
 
 
-def visit_hazmat_node(self, node):
+def html_visit_hazmat_node(self, node):
     return self.visit_admonition(node, "danger")
 
 
+def latex_visit_hazmat_node(self, node):
+    return self.visit_admonition(node)
+
+
 def depart_hazmat_node(self, node):
     return self.depart_admonition(node)
 
@@ -42,6 +46,7 @@ def depart_hazmat_node(self, node):
 def setup(app):
     app.add_node(
         Hazmat,
-        html=(visit_hazmat_node, depart_hazmat_node)
+        html=(html_visit_hazmat_node, depart_hazmat_node),
+        latex=(latex_visit_hazmat_node, depart_hazmat_node),
     )
     app.add_directive("hazmat", HazmatDirective)
diff --git a/docs/hazmat/bindings/index.rst b/docs/hazmat/bindings/index.rst
index 19e03999..11355bfa 100644
--- a/docs/hazmat/bindings/index.rst
+++ b/docs/hazmat/bindings/index.rst
@@ -7,3 +7,4 @@ Bindings
     :maxdepth: 1
 
     openssl
+    interfaces
diff --git a/docs/hazmat/bindings/interfaces.rst b/docs/hazmat/bindings/interfaces.rst
new file mode 100644
index 00000000..c55d86dc
--- /dev/null
+++ b/docs/hazmat/bindings/interfaces.rst
@@ -0,0 +1,137 @@
+.. hazmat::
+
+Backend Interfaces
+==================
+
+.. currentmodule:: cryptography.hazmat.bindings.interfaces
+
+
+Backend implementations may provide a number of interfaces to support operations
+such as :doc:`/hazmat/primitives/symmetric-encryption`,
+:doc:`/hazmat/primitives/cryptographic-hashes`, and
+:doc:`/hazmat/primitives/hmac`.
+
+A specific ``backend`` may provide one or more of these interfaces.
+
+
+.. class:: CipherBackend
+
+    A backend which provides methods for using ciphers for encryption
+    and decryption.
+
+    .. method:: cipher_supported(cipher, mode)
+
+        Check if a ``cipher`` and ``mode`` combination is supported by
+        this backend.
+
+        :param cipher: An instance of a
+            :class:`~cryptography.hazmat.primitives.interfaces.CipherAlgorithm`
+            provider.
+        :param mode: An instance of a
+            :class:`~cryptography.hazmat.primitives.interfaces.Mode` provider.
+
+        :returns: ``True`` if the specified ``cipher`` and ``mode`` combination
+            is supported by this backend, otherwise ``False``
+
+    .. method:: register_cipher_adapter(cipher_cls, mode_cls, adapter)
+
+        Register an adapter which can be used to create a backend specific
+        object from instances of the
+        :class:`~cryptography.hazmat.primitives.interfaces.CipherAlgorithm` and
+        the :class:`~cryptography.hazmat.primitives.interfaces.Mode` primitives.
+
+        :param cipher_cls: A class whose instances provide
+            :class:`~cryptography.hazmat.primitives.interfaces.CipherAlgorithm`
+        :param mode_cls: A class whose instances provide:
+            :class:`~cryptography.hazmat.primitives.interfaces.Mode`
+        :param adapter: A ``function`` that takes 3 arguments, ``backend`` (a
+            :class:`CipherBackend` provider), ``cipher`` (a
+            :class:`~cryptography.hazmat.primitives.interfaces.CipherAlgorithm`
+            provider ), and ``mode`` (a
+            :class:`~cryptography.hazmat.primitives.interfaces.Mode` provider).
+            It returns a backend specific object which may be used to construct
+            a :class:`~cryptogrpahy.hazmat.primitives.interfaces.CipherContext`.
+
+
+    .. method:: create_symmetric_encryption_ctx(cipher, mode)
+
+        Create a
+        :class:`~cryptogrpahy.hazmat.primitives.interfaces.CipherContext` that
+        can be used for encrypting data with the symmetric ``cipher`` using
+        the given ``mode``.
+
+        :param cipher: An instance of a
+            :class:`~cryptography.hazmat.primitives.interfaces.CipherAlgorithm`
+            provider.
+        :param mode: An instance of a
+            :class:`~cryptography.hazmat.primitives.interfaces.Mode` provider.
+
+        :returns:
+            :class:`~cryptography.hazmat.primitives.interfaces.CipherContext`
+
+
+    .. method:: create_symmetric_decryption_ctx(cipher, mode)
+
+        Create a
+        :class:`~cryptogrpahy.hazmat.primitives.interfaces.CipherContext` that
+        can be used for decrypting data with the symmetric ``cipher`` using
+        the given ``mode``.
+
+        :param cipher: An instance of a
+            :class:`~cryptography.hazmat.primitives.interfaces.CipherAlgorithm`
+            provider.
+        :param mode: An instance of a
+            :class:`~cryptography.hazmat.primitives.interfaces.Mode` provider.
+
+        :returns:
+            :class:`~cryptography.hazmat.primitives.interfaces.CipherContext`
+
+
+.. class:: HashBackend
+
+    A backend with methods for using cryptographic hash functions.
+
+    .. method:: hash_supported(algorithm)
+
+        Check if the specified ``algorithm`` is supported by this backend.
+
+        :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``.
+
+
+    .. method:: create_hash_ctx(algorithm)
+
+        Create a
+        :class:`~cryptogrpahy.hazmat.primitives.interfaces.HashContext` that
+        uses the specified ``algorithm`` to calculate a message digest.
+
+        :param algorithm: An instance of a
+            :class:`~cryptography.hazmat.primitives.interfaces.HashAlgorithm`
+            provider.
+
+        :returns:
+            :class:`~cryptography.hazmat.primitives.interfaces.HashContext`
+
+
+.. class:: HMACBackend
+
+    A backend with methods for using cryptographic hash functions as message
+    authentication codes.
+
+    .. method:: create_hmac_ctx(algorithm)
+
+        Create a
+        :class:`~cryptogrpahy.hazmat.primitives.interfaces.HashContext` that
+        uses the specified ``algorithm`` to calculate a hash-based message
+        authentication code.
+
+        :param algorithm: An instance of a
+            :class:`~cryptography.hazmat.primitives.interfaces.HashAlgorithm`
+            provider.
+
+        :returns:
+            :class:`~cryptography.hazmat.primitives.interfaces.HashContext`