From mboxrd@z Thu Jan  1 00:00:00 1970
From: ludo@gnu.org (Ludovic =?UTF-8?Q?Court=C3=A8s?=)
Subject: bug#23605: /dev/urandom not seeded across reboots
Date: Sat, 28 May 2016 15:51:58 +0200
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References: <20160523175832.GA10646@jasmine> <87d1obabj8.fsf@gnu.org>
	<20160528011201.GA1753@jasmine>
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To: Leo Famulari <leo@famulari.name>
Cc: 23605@debbugs.gnu.org

Leo Famulari <leo@famulari.name> skribis:

> On Tue, May 24, 2016 at 02:24:59PM +0200, Ludovic Court=C3=A8s wrote:
>> Leo Famulari <leo@famulari.name> skribis:
>>=20
>> > I realized that we don't seem to be saving any of the entropy in the
>> > kernel's random pool [0] across reboots.
>> >
>> > This means that for some period after boot, /dev/urandom may not be sa=
fe
>> > to use. From random(4):
>>=20
>> Good catch!
>>=20
>> Some comments:
>>=20
>> > +(define %urandom-seed-activation
>> > +  ;; Activation gexp for the urandom seed
>> > +  #~(begin
>> > +      (use-modules (guix build utils))
>> > +
>> > +      (mkdir-p "/var/run")
>> > +      (close-port (open-file "/var/run/urandom-seed" "a0b"))
>>=20
>> Or simply =E2=80=98open-output-file=E2=80=99.
>
> I don't see a way to use (open-output-file) in "append" mode as with
> (open-file).  Without that, the file is cleared before it is read in the
> following lines.

You=E2=80=99re right, sorry for the confusion.

Ludo=E2=80=99.