[Pkg-sysvinit-devel] Bug#587665: Bug#587665: wrong PATH in urandom, find is in /usr/bin

[Henrique de Moraes Holschuh]

On Thu, 01 Jul 2010, Petter Reinholdtsen wrote:
> Perhaps ls round up to the nearest block?  Any other ideas on how to
> fix this with the tools available on /?

I'm looking at the kernel code for random.c right now.  To me it looks like
we can just drop the test for file size.  When (and why) did we add it?  Was
it in response to some particular security concern?

In 2.6.32, it looks like whatever you toss into /dev/u?random gets *MIXED*
in the two pools, and does NOT contribute to the measurement of the entropy
contained in the pool.  So, it stirs up the pool but doens't cause the
entropy estimation to increase, nor triggers the catastrophic reseed
process, etc.

At first glance, it looks to me like a short write will not leave you in a
state any *worse* than you were before the short write.

OTOH, it is a very nasty situation to have a broken random seeding, and we
really should warn the user if that happens.  But we could easily have two
scripts, one that runs VERY early to do the reseeding (using something like
cat or dd to feed the data to /dev/random or to /dev/urandom), and the other
that runs much later to check if the seeding was done properly, and log a
message at the LOG_CRIT level if it wasn't.

-- 
  "One disk to rule them all, One disk to find them. One disk to bring
  them all and in the darkness grind them. In the Land of Redmond
  where the shadows lie." -- The Silicon Valley Tarot
  Henrique Holschuh