Added CMAC interface

1 files changed, 20 insertions, 0 deletions

diff --git a/cryptography/hazmat/primitives/interfaces.py b/cryptography/hazmat/primitives/interfaces.py
index e70338ba..ec970e68 100644
--- a/cryptography/hazmat/primitives/interfaces.py
+++ b/cryptography/hazmat/primitives/interfaces.py
@@ -457,3 +457,23 @@ class KeyDerivationFunction(object):
         Checks whether the key generated by the key material matches the
         expected derived key. Raises an exception if they do not match.
         """
+
+
+@six.add_metaclass(abc.ABCMeta)
+class CMACContext(object):
+    @abc.abstractmethod
+    def update(self, data):
+        """
+        Processes the provided bytes.
+        """
+
+    def finalize(self):
+        """
+        Returns the results of processing the final block as bytes.
+        """
+
+    @abc.abstractmethod
+    def copy(self):
+        """
+        Return a CMACContext that is a copy of the current context.
+        """