On Thu, Jan 19, 2012 at 07:52:30PM +0000, Mark Murray wrote: > Andrey Chernov writes: > > On Mon, Jan 16, 2012 at 08:18:10PM +0000, David Schultz wrote: > > > Author: das > > > Date: Mon Jan 16 20:18:10 2012 > > > New Revision: 230230 > > > URL: http://svn.freebsd.org/changeset/base/230230 > > > > > > Log: > > > Generate a warning if the kernel's arc4random() is seeded with bogus > > > entropy. > > > > While you are here, could you review/commit my patch to fix bad 31bit > > arc4rand() seeding, please? > > > > --- yarrow.c.bak 2011-09-26 07:35:48.000000000 +0400 > > +++ yarrow.c 2012-01-18 10:13:47.000000000 +0400 > > This is the wrong place for this; it may achieve the desired result, but > the file is where the Yarrow algorithm is implepeneted; ARC4 reseeds are > not a part of that, which makes this proposal a layering violation at > best, and an unwarranted dependancy at worst. > > Look at the function random_yarrow_unblock(). Thats where yopu want to > be doing this. This function is where the random device is unblocked > once safely seeded.
Thanx for your hint, but I fear one moment using random_yarrow_unblock(). It is called under mtx_lock(&random_reseed_mtx) in reseed(). And when arc4rand() seeding is called, it uses read_random(), so I see possible deadlock can happens. In my version arc4rand() seeding happens only when this lock is released, so no blocking is possible. But perhaps I oversight something, correct me if I am wrong, please. -- http://ache.vniz.net/ _______________________________________________ svn-src-head@freebsd.org mailing list http://lists.freebsd.org/mailman/listinfo/svn-src-head To unsubscribe, send any mail to "svn-src-head-unsubscr...@freebsd.org"
