From mboxrd@z Thu Jan 1 00:00:00 1970 From: "Thompson, David" Subject: bug#23605: /dev/urandom not seeded across reboots Date: Tue, 24 May 2016 12:26:29 -0400 Message-ID: References: <20160523175832.GA10646@jasmine> <87shx8j5qm.fsf@T420.taylan> <20160524161617.GC29516@jasmine> Mime-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: quoted-printable Return-path: Received: from eggs.gnu.org ([2001:4830:134:3::10]:59275) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1b5FAg-0001Nk-Fz for bug-guix@gnu.org; Tue, 24 May 2016 12:27:10 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1b5FAb-0003aC-Us for bug-guix@gnu.org; Tue, 24 May 2016 12:27:06 -0400 Received: from debbugs.gnu.org ([208.118.235.43]:52504) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1b5FAb-0003a8-PH for bug-guix@gnu.org; Tue, 24 May 2016 12:27:01 -0400 Received: from Debian-debbugs by debbugs.gnu.org with local (Exim 4.84_2) (envelope-from ) id 1b5FAb-0006l0-Lq for bug-guix@gnu.org; Tue, 24 May 2016 12:27:01 -0400 Sender: "Debbugs-submit" Resent-Message-ID: In-Reply-To: <20160524161617.GC29516@jasmine> List-Id: Bug reports for GNU Guix List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: bug-guix-bounces+gcggb-bug-guix=m.gmane.org@gnu.org Sender: "bug-Guix" To: Leo Famulari Cc: 23605@debbugs.gnu.org On Tue, May 24, 2016 at 12:16 PM, Leo Famulari wrote: > On Tue, May 24, 2016 at 09:05:21AM +0200, Taylan Ulrich Bay=C4=B1rl=C4=B1= /Kammer wrote: >> Leo Famulari writes: >> > Does anyone have advice about the service? Am I wrong that we need to >> > seed /dev/urandom to make it work properly? >> >> Yes, this is necessary under Linux if you want urandom to be random >> enough immediately after boot, and all the distros do it as part of >> their init. >> >> There's also an interesting implication here about the very first time >> you boot the system and don't have a urandom seed file from the last >> shutdown yet. I don't know how this is typically handled, given that >> for instance it's quite possible that a user might generate SSH keys >> shortly after their first boot of a system. > > When I boot a GuixSD VM for the first time [0], it requires me to dance > on the keyboard until it has collected ~200 bits of entropy. I assumed > this is to properly bootstrap the CSPRNG in /dev/urandom, but I'm not > sure. This is just an annoying feature of GNU lsh. I want to switch my machines to OpenSSH sometime, partly due to this. - Dave