linux-kernel - Re: [RFC/PATCH 0/3] Add devicetree scanning for randomness

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: <20140212182000.GJ5554@obsidianresearch.com>
Date:	Wed, 12 Feb 2014 11:20:00 -0700
From:	Jason Gunthorpe <jgunthorpe@...idianresearch.com>
To:	Jason Cooper <jason@...edaemon.net>
Cc:	Arnd Bergmann <arnd@...db.de>, keescook@...omium.org,
	devicetree@...r.kernel.org, Laura Abbott <lauraa@...eaurora.org>,
	linux-kernel@...r.kernel.org, Rob Herring <robh+dt@...nel.org>,
	Kumar Gala <galak@...eaurora.org>,
	Grant Likely <grant.likely@...aro.org>,
	linux-arm-kernel@...ts.infradead.org
Subject: Re: [RFC/PATCH 0/3] Add devicetree scanning for randomness

On Wed, Feb 12, 2014 at 12:45:54PM -0500, Jason Cooper wrote:

> The bootloader would then load this file into ram, and pass the
> address/size to the kernel either via dt, or commandline.  kaslr (run in
> the decompressor) would consume some of this randomness, and then
> random.c would consume the rest in a non-crediting initialization.

Sure is a neat idea, but I think in general it would probably be smart
to include the entire FDT blob in the early random pool, that way you
get MACs and other machine unique data too.

>From there it is a small step to encourage bootloaders to include
boot-time-variable data in the DT like like 'boot time of day', 'cycle
counter', 'random blob', etc.

Then you just need the bootloader to dump the random-seed file into a
DT property.

Or have the bootloader fetch randomness from any HWRNG it has a driver
for. (eg a TPM)

Jason
--
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/