From: "Thompson, David" <dthompson2@worcester.edu>
To: Leo Famulari <leo@famulari.name>
Cc: 23605@debbugs.gnu.org
Subject: bug#23605: /dev/urandom not seeded across reboots
Date: Tue, 24 May 2016 13:29:44 -0400 [thread overview]
Message-ID: <CAJ=RwfaBjocoPiPztPQdxvAB_Cq_ZBydNJV1dnVEGY4FRHjp5w@mail.gmail.com> (raw)
In-Reply-To: <20160524172329.GA5216@jasmine>
On Tue, May 24, 2016 at 1:23 PM, Leo Famulari <leo@famulari.name> wrote:
> On Tue, May 24, 2016 at 12:26:29PM -0400, Thompson, David wrote:
>> On Tue, May 24, 2016 at 12:16 PM, Leo Famulari <leo@famulari.name> wrote:
>> > On Tue, May 24, 2016 at 09:05:21AM +0200, Taylan Ulrich Bayırlı/Kammer wrote:
>> >> Leo Famulari <leo@famulari.name> 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.
>
> Well, it seems that this feature might be protecting us against using
> weak SSH session keys on first boot, if it's doing what I think it's
> doing...
It impedes automated provisioning of servers, which OpenSSH does not do.
- Dave
next prev parent reply other threads:[~2016-05-24 17:30 UTC|newest]
Thread overview: 26+ messages / expand[flat|nested] mbox.gz Atom feed top
2016-05-23 17:58 bug#23605: /dev/urandom not seeded across reboots Leo Famulari
2016-05-24 7:05 ` Taylan Ulrich Bayırlı/Kammer
2016-05-24 16:16 ` Leo Famulari
2016-05-24 16:26 ` Thompson, David
2016-05-24 17:23 ` Leo Famulari
2016-05-24 17:29 ` Thompson, David [this message]
2016-05-25 21:53 ` Ludovic Courtès
2016-05-24 12:24 ` Ludovic Courtès
2016-05-25 16:38 ` Leo Famulari
2016-05-25 16:54 ` Ludovic Courtès
2016-05-26 16:47 ` Leo Famulari
2016-05-28 13:57 ` Ludovic Courtès
2016-05-28 18:05 ` Leo Famulari
2016-05-28 18:10 ` Leo Famulari
2016-05-28 18:26 ` Leo Famulari
2016-05-28 20:41 ` Leo Famulari
2016-05-28 20:53 ` Ludovic Courtès
2016-05-29 0:00 ` Leo Famulari
2016-05-29 0:04 ` Leo Famulari
2016-05-29 20:23 ` Ludovic Courtès
2016-05-28 1:12 ` Leo Famulari
2016-05-28 13:51 ` Ludovic Courtès
2016-05-28 1:05 ` Leo Famulari
2016-05-28 1:11 ` Ben Woodcroft
2016-05-28 1:45 ` Leo Famulari
2016-05-28 9:40 ` Ben Woodcroft
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