Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752581AbXLHRlS (ORCPT ); Sat, 8 Dec 2007 12:41:18 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1750739AbXLHRlG (ORCPT ); Sat, 8 Dec 2007 12:41:06 -0500 Received: from mx1.redhat.com ([66.187.233.31]:38615 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750705AbXLHRlF (ORCPT ); Sat, 8 Dec 2007 12:41:05 -0500 Message-ID: <475AD585.7020908@redhat.com> Date: Sat, 08 Dec 2007 11:33:57 -0600 From: Mike McGrath User-Agent: Thunderbird 2.0.0.5 (X11/20070719) MIME-Version: 1.0 To: Theodore Tso , Jon Masters , Mike McGrath , Matt Mackall , Alan Cox , Ray Lee , Adrian Bunk , Marc Haber , linux-kernel@vger.kernel.org Subject: Re: Why does reading from /dev/urandom deplete entropy so much? References: <20071204195021.GB7259@thunk.org> <20071204204036.484f11ac@the-village.bc.nu> <20071204210827.GE19691@waste.org> <4755C423.60907@redhat.com> <20071204221525.GG19691@waste.org> <4755D350.1080801@redhat.com> <20071204223345.GJ19691@waste.org> <4756B50B.3060100@redhat.com> <20071205144934.GL7259@thunk.org> <1197099477.20786.149.camel@perihelion> <20071208173204.GI17037@thunk.org> In-Reply-To: <20071208173204.GI17037@thunk.org> Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1316 Lines: 29 Theodore Tso wrote: > On Sat, Dec 08, 2007 at 02:37:57AM -0500, Jon Masters wrote: > >>> BTW, You may be better off using "uuidgen -t" to generate the UUID in >>> the smolt RPM, since that will use 12 bits of randomness from >>> /dev/random, plus the MAC, address and timestamp. So even if there is >>> zero randomness in /dev/random, and the time is January 1, 1970, at >>> least the MAC will contribute some uniqueness to the UUID. >>> >> I haven't checked how uuidgen uses the MAC, but I would suggest that >> that is not something Fedora should jump at doing - although it would >> help ensure unique UUIDs, it also contributes to the tinfoil hat >> responses that usually come up with things like smolt. >> > > Huh? What's the concern? All you are submitting is a list of > hardware devices in your system. That's hardly anything sensitive.... > We actually had a very vocal minority about all of that which ended up putting us in the unfortunate position of generating a random UUID instead of using a hardware UUID from hal :-/ -Mike -- 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/