From: Jean-Francois Moine <moinejf@free.fr>
To: LABBE Corentin <clabbe.montjoie@gmail.com>
Cc: Maxime Ripard <maxime.ripard@free-electrons.com>,
wens@csie.org, srinivas.kandagatla@linaro.org,
linux-kernel@vger.kernel.org,
linux-arm-kernel@lists.infradead.org,
linux-crypto@vger.kernel.org
Subject: Re: [PATCH] nvmem: sunxi-sid: SID content is not a valid source of randomness
Date: Tue, 25 Oct 2016 09:06:34 +0200 [thread overview]
Message-ID: <20161025090634.3dae9ad52ae8382dde6af4c8@free.fr> (raw)
In-Reply-To: <20161025053855.GA901@Red>
On Tue, 25 Oct 2016 07:38:55 +0200
LABBE Corentin <clabbe.montjoie@gmail.com> wrote:
> > On Sat, Oct 22, 2016 at 03:53:28PM +0200, Corentin Labbe wrote:
> > > Since SID's content is constant over reboot,
> >
> > That's not true, at least not across all the Allwinner SoCs, and
> > especially not on the A10 and A20 that this driver supports.
> >
>
> On my cubieboard2 (A20)
> hexdump -C /sys/devices/platform/soc\@01c00000/1c23800.eeprom/sunxi-sid0/nvmem
> 00000000 16 51 66 83 80 48 50 72 56 54 48 48 03 c2 75 72 |.Qf..HPrVTHH..ur|
> 00000010 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 |................|
> *
> 00000100 16 51 66 83 80 48 50 72 56 54 48 48 03 c2 75 72 |.Qf..HPrVTHH..ur|
> 00000110 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 |................|
> *
> 00000200
> cubiedev ~ # reboot
> cubiedev ~ # hexdump -C /sys/devices/platform/soc\@01c00000/1c23800.eeprom/sunxi-sid0/nvmem
> 00000000 16 51 66 83 80 48 50 72 56 54 48 48 03 c2 75 72 |.Qf..HPrVTHH..ur|
> 00000010 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 |................|
> *
> 00000100 16 51 66 83 80 48 50 72 56 54 48 48 03 c2 75 72 |.Qf..HPrVTHH..ur|
> 00000110 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 |................|
> *
> 00000200
>
> So clearly for me its constant.
Even after power off/power on?
--
Ken ar c'hentañ | ** Breizh ha Linux atav! **
Jef | http://moinejf.free.fr/
next prev parent reply other threads:[~2016-10-25 7:16 UTC|newest]
Thread overview: 7+ messages / expand[flat|nested] mbox.gz Atom feed top
2016-10-22 13:53 Corentin Labbe
2016-10-24 20:10 ` Maxime Ripard
2016-10-25 5:38 ` LABBE Corentin
2016-10-25 7:06 ` Jean-Francois Moine [this message]
2016-10-28 12:37 ` LABBE Corentin
2016-10-25 13:26 ` Maxime Ripard
2016-11-10 15:14 ` Corentin Labbe
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