From owner-freebsd-security@FreeBSD.ORG  Tue Mar  8 15:25:29 2005
Return-Path: <owner-freebsd-security@FreeBSD.ORG>
Delivered-To: freebsd-security@freebsd.org
Received: from mx1.FreeBSD.org (mx1.freebsd.org [216.136.204.125])
	by hub.freebsd.org (Postfix) with ESMTP id 660F116A4CE
	for <freebsd-security@FreeBSD.ORG>;
	Tue,  8 Mar 2005 15:25:29 +0000 (GMT)
Received: from VARK.MIT.EDU (VARK.MIT.EDU [18.95.3.179])
	by mx1.FreeBSD.org (Postfix) with ESMTP id EC6A443D41
	for <freebsd-security@FreeBSD.ORG>;
	Tue,  8 Mar 2005 15:25:28 +0000 (GMT)	(envelope-from das@FreeBSD.ORG)
Received: from VARK.MIT.EDU (localhost [127.0.0.1])
	by VARK.MIT.EDU (8.13.3/8.13.1) with ESMTP id j28FOYq5002179;
	Tue, 8 Mar 2005 10:24:34 -0500 (EST)
	(envelope-from das@FreeBSD.ORG)
Received: (from das@localhost)
	by VARK.MIT.EDU (8.13.3/8.13.1/Submit) id j28FOUWZ002178;
	Tue, 8 Mar 2005 10:24:30 -0500 (EST)
	(envelope-from das@FreeBSD.ORG)
Date: Tue, 8 Mar 2005 10:24:30 -0500
From: David Schultz <das@FreeBSD.ORG>
To: Richard Coleman <rcoleman@criticalmagic.com>
Message-ID: <20050308152430.GA1999@VARK.MIT.EDU>
Mail-Followup-To: Richard Coleman <rcoleman@criticalmagic.com>,
	Ian G <iang@iang.org>, freebsd-security@FreeBSD.ORG
References: <999.1110223995@critter.freebsd.dk> <422D9B5E.3020303@iang.org>
	<422DB45E.2050900@criticalmagic.com>
Mime-Version: 1.0
Content-Type: text/plain; charset=us-ascii
Content-Disposition: inline
In-Reply-To: <422DB45E.2050900@criticalmagic.com>
cc: freebsd-security@FreeBSD.ORG
cc: Ian G <iang@iang.org>
Subject: Re: New entropy source proposal.
X-BeenThere: freebsd-security@freebsd.org
X-Mailman-Version: 2.1.1
Precedence: list
List-Id: Security issues [members-only posting]
	<freebsd-security.freebsd.org>
List-Unsubscribe: <http://lists.freebsd.org/mailman/listinfo/freebsd-security>,
	<mailto:freebsd-security-request@freebsd.org?subject=unsubscribe>
List-Archive: <http://lists.freebsd.org/pipermail/freebsd-security>
List-Post: <mailto:freebsd-security@freebsd.org>
List-Help: <mailto:freebsd-security-request@freebsd.org?subject=help>
List-Subscribe: <http://lists.freebsd.org/mailman/listinfo/freebsd-security>,
	<mailto:freebsd-security-request@freebsd.org?subject=subscribe>
X-List-Received-Date: Tue, 08 Mar 2005 15:25:29 -0000

On Tue, Mar 08, 2005, Richard Coleman wrote:
> Ian G wrote:
> >You might want to check out:
> >
> >http://www.av8n.com/turbid/paper/turbid.htm
> >
> >There is some controversy over the new FreeBSD /dev/random system,
> >is there any analysis of the system?  I wasn't able to find anything
> >from a brief search.
> >
> >iang
> 
> The FreeBSD /dev/random was originally based on the Yarrow paper that is 
> given as a reference in the paper above.  But I think the current 
> implementation is more similar to to the version of Yarrow that is 
> discussed in Bruce Schneier's "Practical Cryptography".  I'm not sure if 
> that is a coincidence or not.
> 
> The paper mentioned above only briefly mentions Yarrow, and doesn't 
> mention the FreeBSD implementation, so it's hard to compare the two.
> 
> At first glance, both systems appear strong.

There's also:

	http://www.usenix.org/publications/library/proceedings/bsdcon02/full_papers/murray/murray_html/

The only objection with it that I'm aware of is that the random
device does not ordinarily block, which may make it vulnerable to
side channel or cryptanalytic attacks.