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
This is a large change to CSRF protection for Django. It includes:
* removing the dependency on the session framework.
* deprecating CsrfResponseMiddleware, and replacing with a core template tag.
* turning on CSRF protection by default by adding CsrfViewMiddleware to
the default value of MIDDLEWARE_CLASSES.
* protecting all contrib apps (whatever is in settings.py)
using a decorator.
For existing users of the CSRF functionality, it should be a seamless update,
but please note that it includes DEPRECATION of features in Django 1.1,
and there are upgrade steps which are detailed in the docs.
Many thanks to 'Glenn' and 'bthomas', who did a lot of the thinking and work
on the patch, and to lots of other people including Simon Willison and
Russell Keith-Magee who refined the ideas.
Details of the rationale for these changes is found here:
http://code.djangoproject.com/wiki/CsrfProtection
As of this commit, the CSRF code is mainly in 'contrib'. The code will be
moved to core in a separate commit, to make the changeset as readable as
possible.
git-svn-id: http://code.djangoproject.com/svn/django/trunk@11660 bcc190cf-cafb-0310-a4f2-bffc1f526a37
