Merge pull request #1423 from alex/pr/1396
Add MACContext and switch HMAC and CMAC to use it
diff --git a/CHANGELOG.rst b/CHANGELOG.rst
index 70e30e6..c8cec58 100644
--- a/CHANGELOG.rst
+++ b/CHANGELOG.rst
@@ -8,6 +8,9 @@
* More bit-lengths are now support for ``p`` and ``q`` when loading DSA keys
from numbers.
+* Added :class:`~cryptography.hazmat.primitives.interfaces.MACContext` as a
+ common interface for CMAC and HMAC and deprecated
+ :class:`~cryptography.hazmat.primitives.interfaces.CMACContext`.
0.6.1 - 2014-10-15
~~~~~~~~~~~~~~~~~~
diff --git a/cryptography/hazmat/backends/interfaces.py b/cryptography/hazmat/backends/interfaces.py
index 69d776f..ecb5bf4 100644
--- a/cryptography/hazmat/backends/interfaces.py
+++ b/cryptography/hazmat/backends/interfaces.py
@@ -66,7 +66,7 @@
@abc.abstractmethod
def create_hmac_ctx(self, key, algorithm):
"""
- Create a HashContext for calculating a message authentication code.
+ Create a MACContext for calculating a message authentication code.
"""
@@ -81,7 +81,7 @@
@abc.abstractmethod
def create_cmac_ctx(self, algorithm):
"""
- Create a CMACContext for calculating a message authentication code.
+ Create a MACContext for calculating a message authentication code.
"""
diff --git a/cryptography/hazmat/backends/openssl/cmac.py b/cryptography/hazmat/backends/openssl/cmac.py
index 7acf439..da7b748 100644
--- a/cryptography/hazmat/backends/openssl/cmac.py
+++ b/cryptography/hazmat/backends/openssl/cmac.py
@@ -20,7 +20,7 @@
from cryptography.hazmat.primitives.ciphers.modes import CBC
-@utils.register_interface(interfaces.CMACContext)
+@utils.register_interface(interfaces.MACContext)
class _CMACContext(object):
def __init__(self, backend, algorithm, ctx=None):
if not backend.cmac_algorithm_supported(algorithm):
diff --git a/cryptography/hazmat/primitives/cmac.py b/cryptography/hazmat/primitives/cmac.py
index fa463ae..7ae5c11 100644
--- a/cryptography/hazmat/primitives/cmac.py
+++ b/cryptography/hazmat/primitives/cmac.py
@@ -21,7 +21,7 @@
from cryptography.hazmat.primitives import constant_time, interfaces
-@utils.register_interface(interfaces.CMACContext)
+@utils.register_interface(interfaces.MACContext)
class CMAC(object):
def __init__(self, algorithm, backend, ctx=None):
if not isinstance(backend, CMACBackend):
diff --git a/cryptography/hazmat/primitives/hmac.py b/cryptography/hazmat/primitives/hmac.py
index 026ad3b..2329243 100644
--- a/cryptography/hazmat/primitives/hmac.py
+++ b/cryptography/hazmat/primitives/hmac.py
@@ -21,6 +21,7 @@
from cryptography.hazmat.primitives import constant_time, interfaces
+@utils.register_interface(interfaces.MACContext)
@utils.register_interface(interfaces.HashContext)
class HMAC(object):
def __init__(self, key, algorithm, backend, ctx=None):
diff --git a/cryptography/hazmat/primitives/interfaces.py b/cryptography/hazmat/primitives/interfaces.py
index 6ae0a4c..370fd68 100644
--- a/cryptography/hazmat/primitives/interfaces.py
+++ b/cryptography/hazmat/primitives/interfaces.py
@@ -391,26 +391,6 @@
@six.add_metaclass(abc.ABCMeta)
-class CMACContext(object):
- @abc.abstractmethod
- def update(self, data):
- """
- Processes the provided bytes.
- """
-
- def finalize(self):
- """
- Returns the message authentication code as bytes.
- """
-
- @abc.abstractmethod
- def copy(self):
- """
- Return a CMACContext that is a copy of the current context.
- """
-
-
-@six.add_metaclass(abc.ABCMeta)
class EllipticCurve(object):
@abc.abstractproperty
def name(self):
@@ -486,3 +466,34 @@
"""
Returns an EllipticCurvePublicNumbers.
"""
+
+
+@six.add_metaclass(abc.ABCMeta)
+class MACContext(object):
+ @abc.abstractmethod
+ def update(self, data):
+ """
+ Processes the provided bytes.
+ """
+
+ @abc.abstractmethod
+ def finalize(self):
+ """
+ Returns the message authentication code as bytes.
+ """
+
+ @abc.abstractmethod
+ def copy(self):
+ """
+ Return a MACContext that is a copy of the current context.
+ """
+
+ @abc.abstractmethod
+ def verify(self, signature):
+ """
+ Checks if the generated message authentication code matches the
+ signature.
+ """
+
+# DeprecatedIn07
+CMACContext = MACContext
diff --git a/docs/hazmat/primitives/interfaces.rst b/docs/hazmat/primitives/interfaces.rst
index 2d594c8..4cb64c8 100644
--- a/docs/hazmat/primitives/interfaces.rst
+++ b/docs/hazmat/primitives/interfaces.rst
@@ -643,11 +643,13 @@
stored derived key.
-`CMAC`_
--------
+`Message Authentication Code`_
+------------------------------
.. class:: CMACContext
+ :class:`CMACContext` has been deprecated in favor of :class:`MACContext`.
+
.. versionadded:: 0.4
.. method:: update(data)
@@ -663,6 +665,30 @@
:return: A :class:`~cryptography.hazmat.primitives.interfaces.CMACContext`
that is a copy of the current context.
+.. class:: MACContext
+
+ .. versionadded:: 0.7
+
+ .. method:: update(data)
+
+ :param data bytes: The data you want to authenticate.
+
+ .. method:: finalize()
+
+ :return: The message authentication code.
+
+ .. method:: copy()
+
+ :return: A
+ :class:`~cryptography.hazmat.primitives.interfaces.MACContext` that
+ is a copy of the current context.
+
+ .. method:: verify(signature)
+
+ :param signature bytes: The signature to verify.
+
+ :raises cryptography.exceptions.InvalidSignature: This is raised when
+ the provided signature does not match the expected signature.
.. _`RSA`: https://en.wikipedia.org/wiki/RSA_(cryptosystem)
.. _`Chinese remainder theorem`: https://en.wikipedia.org/wiki/Chinese_remainder_theorem