From mboxrd@z Thu Jan 1 00:00:00 1970 From: Leo Famulari Subject: Re: [PATCH 2/2] services: Add 'dropbear-service'. Date: Sat, 9 Jul 2016 18:41:25 -0400 Message-ID: <20160709224125.GA11385@jasmine> References: <20160704205616.11599-1-david@craven.ch> <20160704205616.11599-2-david@craven.ch> <20160707172517.GA5283@jasmine> Mime-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: 8bit Return-path: Received: from eggs.gnu.org ([2001:4830:134:3::10]:59767) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1bM0wT-0007XY-2h for guix-devel@gnu.org; Sat, 09 Jul 2016 18:41:46 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1bM0wN-00020e-1Z for guix-devel@gnu.org; Sat, 09 Jul 2016 18:41:43 -0400 Received: from out4-smtp.messagingengine.com ([66.111.4.28]:58938) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1bM0wJ-000205-Pu for guix-devel@gnu.org; Sat, 09 Jul 2016 18:41:38 -0400 Content-Disposition: inline In-Reply-To: <20160707172517.GA5283@jasmine> List-Id: "Development of GNU Guix and the GNU System distribution." List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: guix-devel-bounces+gcggd-guix-devel=m.gmane.org@gnu.org Sender: "Guix-devel" To: David Craven Cc: guix-devel@gnu.org On Thu, Jul 07, 2016 at 01:25:17PM -0400, Leo Famulari wrote: > If so, what does Dropbear do? How does it get random numbers to generate > the host key? I looked into it — Dropbear uses /dev/urandom, which *may* not be safe to use immediately after first boot. What do you think about implementing the '-R' option, described below? >From dropbear(8) [0]: "Host key files are read at startup from a standard location, by default /etc/dropbear/dropbear_dss_host_key, /etc/dropbear/dropbear_rsa_host_key, and /etc/dropbear/dropbear_ecdsa_host_key or specified on the commandline with -r. These are of the form generated by dropbearkey. The -R option can be used to automatically generate keys in the default location - keys will be generated after startup when the first connection is established. This had the benefit that the system /dev/urandom random number source has a better chance of being securely seeded." [0] https://github.com/mkj/dropbear/blob/master/dropbear.8#L143