Re: [dane] Digest Algorithm Agility discussion
Viktor Dukhovni <viktor1dane@dukhovni.org> Tue, 18 March 2014 14:14 UTC
Return-Path: <viktor1dane@dukhovni.org>
X-Original-To: dane@ietfa.amsl.com
Delivered-To: dane@ietfa.amsl.com
Received: from localhost (ietfa.amsl.com [127.0.0.1]) by ietfa.amsl.com (Postfix) with ESMTP id D8B271A037C for <dane@ietfa.amsl.com>; Tue, 18 Mar 2014 07:14:09 -0700 (PDT)
X-Virus-Scanned: amavisd-new at amsl.com
X-Spam-Flag: NO
X-Spam-Score: -1.9
X-Spam-Level:
X-Spam-Status: No, score=-1.9 tagged_above=-999 required=5 tests=[BAYES_00=-1.9] autolearn=ham
Received: from mail.ietf.org ([4.31.198.44]) by localhost (ietfa.amsl.com [127.0.0.1]) (amavisd-new, port 10024) with ESMTP id oyGoBRFLQICA for <dane@ietfa.amsl.com>; Tue, 18 Mar 2014 07:14:07 -0700 (PDT)
Received: from mournblade.imrryr.org (mournblade.imrryr.org [38.117.134.19]) by ietfa.amsl.com (Postfix) with ESMTP id A65261A012F for <dane@ietf.org>; Tue, 18 Mar 2014 07:14:06 -0700 (PDT)
Received: by mournblade.imrryr.org (Postfix, from userid 1034) id 494E82AB22D; Tue, 18 Mar 2014 14:13:56 +0000 (UTC)
Date: Tue, 18 Mar 2014 14:13:56 +0000
From: Viktor Dukhovni <viktor1dane@dukhovni.org>
To: dane@ietf.org
Message-ID: <20140318141356.GO24183@mournblade.imrryr.org>
References: <alpine.LFD.2.10.1403171440540.32251@bofh.nohats.ca> <20140317222320.443521AC59@ld9781.wdf.sap.corp> <20140317225329.GK24183@mournblade.imrryr.org> <20140318112647.885B21190C03@rock.dv.isc.org>
MIME-Version: 1.0
Content-Type: text/plain; charset="us-ascii"
Content-Disposition: inline
In-Reply-To: <20140318112647.885B21190C03@rock.dv.isc.org>
User-Agent: Mutt/1.5.23 (2014-03-12)
Archived-At: http://mailarchive.ietf.org/arch/msg/dane/UtgIpagR4vgH8mA_fQHac19C2Zc
Subject: Re: [dane] Digest Algorithm Agility discussion
X-BeenThere: dane@ietf.org
X-Mailman-Version: 2.1.15
Precedence: list
Reply-To: dane@ietf.org
List-Id: DNS-based Authentication of Named Entities <dane.ietf.org>
List-Unsubscribe: <https://www.ietf.org/mailman/options/dane>, <mailto:dane-request@ietf.org?subject=unsubscribe>
List-Archive: <http://www.ietf.org/mail-archive/web/dane/>
List-Post: <mailto:dane@ietf.org>
List-Help: <mailto:dane-request@ietf.org?subject=help>
List-Subscribe: <https://www.ietf.org/mailman/listinfo/dane>, <mailto:dane-request@ietf.org?subject=subscribe>
X-List-Received-Date: Tue, 18 Mar 2014 14:14:10 -0000
On Tue, Mar 18, 2014 at 10:26:47PM +1100, Mark Andrews wrote: > This whole argument of weakest vs strongest was had years ago in > DNSSEC and quite frankly is a waste of time trying to pick the > strongest as you are often comparing apples and oranges. The client ranks the algorithms by preference, in much the same way that TLS ranks cipher-suites by preference and in TLSv1.2 even signature algorithms by preference. It does not matter whether the rankings are objectively justified. The client uses its most preferred digest (perhaps it has hardware support for it). > DNSSEC validators just have a way to say "we no longer trust this > algorithm" and once that is set all records with that algorithm are > ignored when doing validation regardless of whether there is code > to support that algorithm or not. If things are as you describe, this works poorly, since clients continue to accept weak signatures on zones that have both strong and weak signatures (RSA/SHA1 and RSA/SHA256) if the strong signature fails to match the client trusts the weak, right? It becomes difficult to phase out a weak algorithm because the incentive to publish the strong along with the weak is reduced as the benefit from doing so is delayed until clients actually discontinue the weak algorithm. -- Viktor.
- [dane] Digest Algorithm Agility discussion Viktor Dukhovni
- Re: [dane] Digest Algorithm Agility discussion Paul Wouters
- Re: [dane] Digest Algorithm Agility discussion Viktor Dukhovni
- Re: [dane] Digest Algorithm Agility discussion Paul Hoffman
- Re: [dane] Digest Algorithm Agility discussion Paul Wouters
- Re: [dane] Digest Algorithm Agility discussion Viktor Dukhovni
- Re: [dane] Digest Algorithm Agility discussion Viktor Dukhovni
- Re: [dane] Digest Algorithm Agility discussion Paul Hoffman
- Re: [dane] Digest Algorithm Agility discussion Viktor Dukhovni
- Re: [dane] Digest Algorithm Agility discussion Paul Wouters
- Re: [dane] Digest Algorithm Agility discussion Viktor Dukhovni
- Re: [dane] Digest Algorithm Agility discussion Paul Hoffman
- Re: [dane] Digest Algorithm Agility discussion Viktor Dukhovni
- Re: [dane] Digest Algorithm Agility discussion Martin Rex
- Re: [dane] Digest Algorithm Agility discussion Viktor Dukhovni
- Re: [dane] Digest Algorithm Agility discussion Mark Andrews
- Re: [dane] Digest Algorithm Agility discussion Viktor Dukhovni
- Re: [dane] Digest Algorithm Agility discussion (c… Viktor Dukhovni
- Re: [dane] Digest Algorithm Agility discussion Jim Schaad
- Re: [dane] Digest Algorithm Agility discussion (c… Paul Hoffman
- Re: [dane] Digest Algorithm Agility discussion (c… Andrew Sullivan
- Re: [dane] Digest Algorithm Agility discussion (c… Viktor Dukhovni
- Re: [dane] Digest Algorithm Agility discussion (c… Scott Rose
- Re: [dane] Digest Algorithm Agility discussion (c… Viktor Dukhovni
- Re: [dane] Digest Algorithm Agility discussion (c… Scott Rose
- Re: [dane] Digest Algorithm Agility discussion Wes Hardaker
- Re: [dane] Digest Algorithm Agility discussion Viktor Dukhovni
- Re: [dane] Digest Algorithm Agility discussion Peter Palfrader
- Re: [dane] Digest Algorithm Agility discussion Mark Andrews
- Re: [dane] Digest Algorithm Agility discussion Viktor Dukhovni
- Re: [dane] Digest Algorithm Agility discussion Mark Andrews
- Re: [dane] Digest Algorithm Agility discussion Peter Palfrader
- Re: [dane] Digest Algorithm Agility discussion Mark Andrews
- Re: [dane] Digest Algorithm Agility discussion Viktor Dukhovni
- Re: [dane] Digest Algorithm Agility discussion Peter Palfrader
- Re: [dane] Digest Algorithm Agility discussion Viktor Dukhovni
- Re: [dane] Digest Algorithm Agility discussion Mark Andrews
- Re: [dane] Digest Algorithm Agility discussion Mark Andrews
- Re: [dane] Digest Algorithm Agility discussion Viktor Dukhovni
- Re: [dane] Digest Algorithm Agility discussion Paul Wouters
- Re: [dane] Digest Algorithm Agility discussion Viktor Dukhovni
- Re: [dane] Digest Algorithm Agility discussion Peter Palfrader
- Re: [dane] Digest Algorithm Agility discussion Wes Hardaker
- Re: [dane] Digest Algorithm Agility discussion Wes Hardaker