Improved the behavior of get_random_string to re-seed itself each time it is called
if the system does not have a secure random number generator. This will change the
properties of the random string produced, but will be unpredictable to an attacker.
git-svn-id: http://code.djangoproject.com/svn/django/trunk@17581 bcc190cf-cafb-0310-a4f2-bffc1f526a37
Removes several ad hoc implementations of get_random_string()
and removes an innapropriate use of settings.SECRET_KEY.
git-svn-id: http://code.djangoproject.com/svn/django/trunk@17580 bcc190cf-cafb-0310-a4f2-bffc1f526a37
Some existing user passwords may need to be reset or converted
after this change. See the 1.4-beta release notes for more details.
Thanks bhuztez for the report and initial patch, claudep for the test.
git-svn-id: http://code.djangoproject.com/svn/django/trunk@17418 bcc190cf-cafb-0310-a4f2-bffc1f526a37
sha_constructor was incorrectly used instead of sha_hmac (which only made a
difference under 2.4).
Thanks to Steffan Kaminski for report and patch.
git-svn-id: http://code.djangoproject.com/svn/django/trunk@14233 bcc190cf-cafb-0310-a4f2-bffc1f526a37
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
Claude Paroz
Aymeric Augustin
Paul McMillan
Adrian Holovaty
Luke Plant