Merge pull request #231 from dreid/mode-interface-properties

[WIP] Document mode interfaces.

2 files changed, 24 insertions, 3 deletions

diff --git a/cryptography/hazmat/primitives/ciphers/modes.py b/cryptography/hazmat/primitives/ciphers/modes.py
index a60e8a34..e54872a6 100644
--- a/cryptography/hazmat/primitives/ciphers/modes.py
+++ b/cryptography/hazmat/primitives/ciphers/modes.py
@@ -16,6 +16,7 @@ from __future__ import absolute_import, division, print_function
 from cryptography.hazmat.primitives import interfaces
 
 
+@interfaces.register(interfaces.Mode)
 @interfaces.register(interfaces.ModeWithInitializationVector)
 class CBC(object):
     name = "CBC"
@@ -25,10 +26,12 @@ class CBC(object):
         self.initialization_vector = initialization_vector
 
 
+@interfaces.register(interfaces.Mode)
 class ECB(object):
     name = "ECB"
 
 
+@interfaces.register(interfaces.Mode)
 @interfaces.register(interfaces.ModeWithInitializationVector)
 class OFB(object):
     name = "OFB"
@@ -38,6 +41,7 @@ class OFB(object):
         self.initialization_vector = initialization_vector
 
 
+@interfaces.register(interfaces.Mode)
 @interfaces.register(interfaces.ModeWithInitializationVector)
 class CFB(object):
     name = "CFB"
@@ -47,6 +51,7 @@ class CFB(object):
         self.initialization_vector = initialization_vector
 
 
+@interfaces.register(interfaces.Mode)
 @interfaces.register(interfaces.ModeWithNonce)
 class CTR(object):
     name = "CTR"
diff --git a/cryptography/hazmat/primitives/interfaces.py b/cryptography/hazmat/primitives/interfaces.py
index ebf5e31e..67dbe6fa 100644
--- a/cryptography/hazmat/primitives/interfaces.py
+++ b/cryptography/hazmat/primitives/interfaces.py
@@ -25,12 +25,28 @@ def register(iface):
     return register_decorator
 
 
+class Mode(six.with_metaclass(abc.ABCMeta)):
+    @abc.abstractproperty
+    def name(self):
+        """
+        A string naming this mode.  (e.g. ECB, CBC)
+        """
+
+
 class ModeWithInitializationVector(six.with_metaclass(abc.ABCMeta)):
-    pass
+    @abc.abstractproperty
+    def initialization_vector(self):
+        """
+        The value of the initialization vector for this mode as bytes.
+        """
 
 
 class ModeWithNonce(six.with_metaclass(abc.ABCMeta)):
-    pass
+    @abc.abstractproperty
+    def nonce(self):
+        """
+        The value of the nonce for this mode as bytes.
+        """
 
 
 class CipherContext(six.with_metaclass(abc.ABCMeta)):
@@ -65,7 +81,7 @@ class HashAlgorithm(six.with_metaclass(abc.ABCMeta)):
     @abc.abstractproperty
     def name(self):
         """
-        A string naming this algorithm. (ex. sha256, md5)
+        A string naming this algorithm. (e.g. sha256, md5)
         """
 
     @abc.abstractproperty