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Date: Fri, 15 Nov 2013 11:07:35 -0800
Message-ID: <CAGXu5j+emFS+Y-=SOE4SM_gAXfR_NWHRXwv8c6CeB7SgGZgKNw@mail.gmail.com> (sfid-20131115_200843_083620_CFBF166E)
Subject: Re: [PATCH] random: seed random_int_secret at least poorly at
 core_initcall time
From: Kees Cook <keescook@chromium.org>
To: Dave Jones <davej@redhat.com>
Cc: "Theodore Ts'o" <tytso@mit.edu>,
	Daniel Borkmann <dborkman@redhat.com>,
	"David S. Miller" <davem@davemloft.net>,
	Florian Weimer <fweimer@redhat.com>, netdev@vger.kernel.org,
	Eric Dumazet <eric.dumazet@gmail.com>,
	linux-wireless@vger.kernel.org
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Sender: linux-wireless-owner@vger.kernel.org

On Fri, Nov 15, 2013 at 10:45 AM, Dave Jones <davej@redhat.com> wrote:
> On Fri, Nov 15, 2013 at 10:33:04AM -0800, Kees Cook wrote:
>
>  > Ingo wanted even more
>  > unpredictability, in the face of total failure from these more dynamic
>  > sources, so x86 also "seeds" itself with the build string and the
>  > boot_params. These last two are hardly high entropy, but they should
>  > at least make 2 different systems not have _identical_ entropy at the
>  > start. It's far from cryptographically secure, but it's something, I
>  > hope.
>
> Those are both likely to be the same on some configurations.
> On x86, we could maybe hash the dmi tables ? Vendor stupidity aside,
> things like serial numbers in those tables _should_ be different.

Yeah, DMI tables were suggested as well. (Hopefully people will start
using -uuid with KVM!) How hard would that be to hook up to the
pre-random-init code?

-Kees

-- 
Kees Cook
Chrome OS Security