Re: [dane] Digest Algorithm Agility discussion
Viktor Dukhovni <viktor1dane@dukhovni.org> Mon, 17 March 2014 19:00 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 6B4C11A04F1 for <dane@ietfa.amsl.com>; Mon, 17 Mar 2014 12:00:41 -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 g-FiXjEH46mO for <dane@ietfa.amsl.com>; Mon, 17 Mar 2014 12:00:39 -0700 (PDT)
Received: from mournblade.imrryr.org (mournblade.imrryr.org [38.117.134.19]) by ietfa.amsl.com (Postfix) with ESMTP id 7FF491A04C1 for <dane@ietf.org>; Mon, 17 Mar 2014 12:00:37 -0700 (PDT)
Received: by mournblade.imrryr.org (Postfix, from userid 1034) id 4F7B62AADF5; Mon, 17 Mar 2014 19:00:28 +0000 (UTC)
Date: Mon, 17 Mar 2014 19:00:28 +0000
From: Viktor Dukhovni <viktor1dane@dukhovni.org>
To: dane@ietf.org
Message-ID: <20140317190028.GG24183@mournblade.imrryr.org>
References: <20140315051704.GY21390@mournblade.imrryr.org> <alpine.LFD.2.10.1403171115580.32251@bofh.nohats.ca> <20140317155049.GB24183@mournblade.imrryr.org> <B4473EDA-DAB4-4CC2-ACCD-B4F8939E5A2C@vpnc.org> <20140317174423.GE24183@mournblade.imrryr.org> <040FB71F-BD97-44A2-A600-B6E69FBD1EE5@vpnc.org> <20140317182219.GF24183@mournblade.imrryr.org> <alpine.LFD.2.10.1403171440540.32251@bofh.nohats.ca>
MIME-Version: 1.0
Content-Type: text/plain; charset="us-ascii"
Content-Disposition: inline
In-Reply-To: <alpine.LFD.2.10.1403171440540.32251@bofh.nohats.ca>
User-Agent: Mutt/1.5.23 (2014-03-12)
Archived-At: http://mailarchive.ietf.org/arch/msg/dane/LUfvnQjr6oA9yXSjhbhaDJiofVg
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: Mon, 17 Mar 2014 19:00:41 -0000
On Mon, Mar 17, 2014 at 02:46:41PM -0400, Paul Wouters wrote: > >My proposal modifies the pseudo-code > >to loop over only those records (for each usage/selector) with the > >strongest digest plus any records with matching type 0. > > So I agree with you that is the right approach. I am not sure if I > agree that we should try and write that into an RFC other than > "according to local policy". > > but the text should clearly not be like 6698, that would technically > violate the RFC if your method of local policy is implemented. The motivation to publish the proposed digest algorithm agility algorithm is to encourage (coerce) server operators to make sure that they always use "cross product" TLSA RRsets: for each usage for each selector(for that usage) for each supported digest for each object (of given usage and selector) publish usage selector mtype(digest) {digest(object)} since the set of digests is the same for every object, it is safe to ignore any subset of the non-zero mtypes. Now this is in some sense already implied by 6698 since the server operator does not know which digests might be excluded by a 6698 4.1 local policy. The goal is to both highlight this requirement, and to encourage (require) clients to implement agility rather than leave it to implementor's imagination. In Postfix, users get to configure which digests are acceptable and their priority. The default is to support both SHA2-256 and SHA2-512 and to prefer the latter. -- 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