Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754193AbXLHUce (ORCPT ); Sat, 8 Dec 2007 15:32:34 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1752442AbXLHUc1 (ORCPT ); Sat, 8 Dec 2007 15:32:27 -0500 Received: from thunk.org ([69.25.196.29]:48469 "EHLO thunker.thunk.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752142AbXLHUc0 (ORCPT ); Sat, 8 Dec 2007 15:32:26 -0500 Date: Sat, 8 Dec 2007 15:31:21 -0500 From: Theodore Tso To: Jeff Garzik Cc: Matt Mackall , Mike McGrath , Jon Masters , Alan Cox , Ray Lee , Adrian Bunk , Marc Haber , linux-kernel@vger.kernel.org, hmh@debian.org Subject: Re: entropy gathering (was Re: Why does reading from /dev/urandom deplete entropy so much?) Message-ID: <20071208203121.GP17037@thunk.org> Mail-Followup-To: Theodore Tso , Jeff Garzik , Matt Mackall , Mike McGrath , Jon Masters , Alan Cox , Ray Lee , Adrian Bunk , Marc Haber , linux-kernel@vger.kernel.org, hmh@debian.org References: <4756B50B.3060100@redhat.com> <20071205144934.GL7259@thunk.org> <1197099477.20786.149.camel@perihelion> <20071208173204.GI17037@thunk.org> <475AD585.7020908@redhat.com> <20071208174908.GJ17037@thunk.org> <20071208181525.GL19691@waste.org> <475AF241.5000809@garzik.org> <20071208195342.GO19691@waste.org> <475AF8D0.1090407@garzik.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <475AF8D0.1090407@garzik.org> User-Agent: Mutt/1.5.15+20070412 (2007-04-11) X-SA-Exim-Connect-IP: X-SA-Exim-Mail-From: tytso@thunk.org X-SA-Exim-Scanned: No (on thunker.thunk.org); SAEximRunCond expanded to false Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2108 Lines: 44 On Sat, Dec 08, 2007 at 03:04:32PM -0500, Jeff Garzik wrote: > That's a bit of a tangent on a tangent. :) Most people don't have a > hardware RNG. Actually, most Business class laptops from IBM/Lenovo, HP, Dell, Fujitsu, and Sony laptops *do* have TPM chips that among other things, contain a slow but (supposedly, if the TPM microprocessors are to be believed) secure hardware random number generator for use as a session key generator. This is thanks to various US legal mandates, such as HIPPA for the medical industry, and not just the paranoid ravings of the MPAA and RIAA. :-) The problem is enabling the TPM isn't trivial, and life gets harder if you want the TPM chip to simultaneously work on dual-boot machines for both Windows and Linux, but it is certainly doable. >> I think we should re-evaluate having an internal path from the hwrngs >> to /dev/[u]random, which will reduce the need for userspace config >> that can go wrong. I think the userspace config problems were mainly due to the fact that there wasn't a single official userspace utility package for the random number package. Comments in drivers/char/random.c for how to set up /etc/init.d/random is Just Not Enough. If we had a single, official random number generator package that contained the configuration, init.d script, as well as the daemon that can do all sorts of different things that you really, Really, REALLY want to do in userspace, including: * FIPS testing (as Jeff suggested --- making sure what you think is randomness isn't 60Hz hum is a Really Good Idea :-) * access to TPM (if available --- I have a vague memory that you may need access to the TPM key to access any of its functions, and the the TPM key is stored in the filesystem) So.... anyone interested in belling the metaphorical cat? :-) - Ted -- 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/