Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752585AbaBQVHx (ORCPT ); Mon, 17 Feb 2014 16:07:53 -0500 Received: from mail-pa0-f43.google.com ([209.85.220.43]:43930 "EHLO mail-pa0-f43.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750939AbaBQVHv (ORCPT ); Mon, 17 Feb 2014 16:07:51 -0500 MIME-Version: 1.0 In-Reply-To: <20140217182312.GV7862@titan.lakedaemon.net> References: <1392168805-14200-1-git-send-email-lauraa@codeaurora.org> <201402121251.06280.arnd@arndb.de> <20140217155419.682F7C401D4@trevor.secretlab.ca> <1418981.0py7JxXCp8@wuerfel> <20140217182312.GV7862@titan.lakedaemon.net> Date: Mon, 17 Feb 2014 22:07:50 +0100 X-Google-Sender-Auth: M13dnXBfjJGmWNw1fP0pbkHU7TA Message-ID: Subject: Re: [RFC/PATCH 0/3] Add devicetree scanning for randomness From: Geert Uytterhoeven To: Jason Cooper Cc: Arnd Bergmann , "linux-arm-kernel@lists.infradead.org" , Grant Likely , Jason Gunthorpe , "devicetree@vger.kernel.org" , Laura Abbott , Kees Cook , "linux-kernel@vger.kernel.org" , Rob Herring , Kumar Gala Content-Type: text/plain; charset=UTF-8 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Mon, Feb 17, 2014 at 7:23 PM, Jason Cooper wrote: >> Could we use a faster hash function that scans the entire device tree and >> then just feed the output of that into add_device_randomness? We probably >> can't expect that there is a lot of entropy in the DT blob, so the >> result wouldn't be all that different in terms of quality of the random >> seed. > > I think it would be easier to identify the few attributes that differ > from board to board (mac address, serial number, etc), and differ from > boot to boot (random-seed, timestamp) and just extract and feed those > in. Isn't identifying those (mostly) a manual process? Calculating a fast hash is fully automatic. Gr{oetje,eeting}s, Geert -- Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert@linux-m68k.org In personal conversations with technical people, I call myself a hacker. But when I'm talking to journalists I just say "programmer" or something like that. -- Linus Torvalds -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/