From owner-freebsd-current Thu Oct 26 2:19:13 2000 Delivered-To: freebsd-current@freebsd.org Received: from citusc17.usc.edu (citusc17.usc.edu [128.125.38.177]) by hub.freebsd.org (Postfix) with ESMTP id 13A5E37B479; Thu, 26 Oct 2000 02:19:12 -0700 (PDT) Received: (from kris@localhost) by citusc17.usc.edu (8.11.1/8.11.1) id e9Q9LQB69685; Thu, 26 Oct 2000 02:21:26 -0700 (PDT) (envelope-from kris) Date: Thu, 26 Oct 2000 02:21:22 -0700 From: Kris Kennaway To: Andrej Cernov Cc: Terry Lambert , Warner Losh , current@FreeBSD.ORG, markm@FreeBSD.ORG Subject: Re: entropy reseeding is totally broken Message-ID: <20001026022122.C69282@citusc17.usc.edu> References: <200010241816.MAA17356@harmony.village.org> <200010251035.DAA19676@usr02.primenet.com> <20001025145028.A81143@nagual.pp.ru> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline User-Agent: Mutt/1.2.5i In-Reply-To: <20001025145028.A81143@nagual.pp.ru>; from ache@nagual.pp.ru on Wed, Oct 25, 2000 at 02:50:29PM +0400 Sender: owner-freebsd-current@FreeBSD.ORG Precedence: bulk X-Loop: FreeBSD.ORG On Wed, Oct 25, 2000 at 02:50:29PM +0400, Andrej Cernov wrote: > It is because /dev/random totally ignore _time_ and not reseed from it, > but no other randomness source available at boot time. We should probably be using the time since boot as ONE thing we seed with, but it only provides maybe 3-4 bits of randomness - meaning if thats all you seed with then your attacker has to brute-force 3-4 bits of state to break the PRNG state as it was at boot time, hardly a difficult challenge :-) Kris To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-current" in the body of the message