Forward ported code from 1.5 that adds backwards compatibility with legacy message length.
See commit 9e7183073f for details.
Thanks to Ofir Ovadia for the initial patch.
Exposing the level name (e.g. "info") makes it possible to prepend
something to the class name. For example, Twitter Bootstrap has
an alert-info class. This class can now be added to the message
using `class="alert-{{ message.level_tag }}".
Because the level_tag was on the end of the `tags` property, it
could not be used in this fashion when extra_tags were given.
Added settings.SESSION_SERIALIZER which is the import path of a serializer
to use for sessions.
Thanks apollo13, carljm, shaib, akaariai, charettes, and dstufft for reviews.
* Renamed the __unicode__ methods
* Applied the python_2_unicode_compatible decorator
* Removed the StrAndUnicode mix-in that is superseded by
python_2_unicode_compatible
* Kept the __unicode__ methods in classes that specifically
test it under Python 2
* Renamed smart_unicode to smart_text (but kept the old name under
Python 2 for backwards compatibility).
* Renamed smart_str to smart_bytes.
* Re-introduced smart_str as an alias for smart_text under Python 3
and smart_bytes under Python 2 (which is backwards compatible).
Thus smart_str always returns a str objects.
* Used the new smart_str in a few places where both Python 2 and 3
want a str.
All adhoc MAC applications have been updated to use HMAC, using SHA1 to
generate unique keys for each application based on the SECRET_KEY, which is
common practice for this situation. In all cases, backwards compatibility
with existing hashes has been maintained, aiming to phase this out as per
the normal deprecation process. In this way, under most normal
circumstances the old hashes will have expired (e.g. by session expiration
etc.) before they become invalid.
In the case of the messages framework and the cookie backend, which was
already using HMAC, there is the possibility of a backwards incompatibility
if the SECRET_KEY is shorter than the default 50 bytes, but the low
likelihood and low impact meant compatibility code was not worth it.
All known instances where tokens/hashes were compared using simple string
equality, which could potentially open timing based attacks, have also been
fixed using a constant-time comparison function.
There are no known practical attacks against the existing implementations,
so these security improvements will not be backported.
git-svn-id: http://code.djangoproject.com/svn/django/trunk@14218 bcc190cf-cafb-0310-a4f2-bffc1f526a37