linux-kernel - Re: Seeding /dev/random not working

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-ID: <de6d2b4f0705290944i69ca8f2dudda10775ebc41c07@mail.gmail.com>
Date:	Tue, 29 May 2007 17:44:37 +0100
From:	"M Macnair" <mmacnair@...il.com>
To:	"Andi Kleen" <andi@...stfloor.org>
Cc:	linux-kernel@...r.kernel.org
Subject: Re: Seeding /dev/random not working

On 29 May 2007 18:58:59 +0200, Andi Kleen <andi@...stfloor.org> wrote:
> "M Macnair" <mmacnair@...il.com> writes:
> >
> > Many distros ship with an init script that saves and restores the
> > entropy pool on startup and shutdown.  The bit that interests me that
> > is called on startup is (my comments):
> >       if [ -f $random_seed ]; then
> >               cat $random_seed >/dev/urandom  # should seed the pool
> .OA
> Writing doesn't actually work; to get real accounted entropy for /dev/random
> you need to use a special ioctl. I ran into this problem some years ago
> and ended up writing http://www.muc.de/~ak/rndfeed.c
>
> -Andi

If this doesn't work, then it seems to me as though all the
debian-esque distros that use equivalents of the above script are
wasting their time, and the man page recommending that technique (man
4 random) is also wrong.  Is that interpretation correct?

Mike
-
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/