[xmpp] DNA prooftypes: advertising support and preference order?
Peter Saint-Andre <stpeter@stpeter.im> Mon, 07 January 2013 17:46 UTC
Return-Path: <stpeter@stpeter.im>
X-Original-To: xmpp@ietfa.amsl.com
Delivered-To: xmpp@ietfa.amsl.com
Received: from localhost (localhost [127.0.0.1]) by ietfa.amsl.com (Postfix) with ESMTP id 5E80C21F8929 for <xmpp@ietfa.amsl.com>; Mon, 7 Jan 2013 09:46:05 -0800 (PST)
X-Virus-Scanned: amavisd-new at amsl.com
X-Spam-Flag: NO
X-Spam-Score: -102.599
X-Spam-Level:
X-Spam-Status: No, score=-102.599 tagged_above=-999 required=5 tests=[BAYES_00=-2.599, USER_IN_WHITELIST=-100]
Received: from mail.ietf.org ([64.170.98.30]) by localhost (ietfa.amsl.com [127.0.0.1]) (amavisd-new, port 10024) with ESMTP id AFCAPsG07TwG for <xmpp@ietfa.amsl.com>; Mon, 7 Jan 2013 09:46:04 -0800 (PST)
Received: from stpeter.im (mailhost.stpeter.im [207.210.219.225]) by ietfa.amsl.com (Postfix) with ESMTP id 606B221F891A for <xmpp@ietf.org>; Mon, 7 Jan 2013 09:46:04 -0800 (PST)
Received: from [10.129.24.67] (unknown [128.107.239.234]) (Authenticated sender: stpeter) by stpeter.im (Postfix) with ESMTPSA id D3CDD404EB for <xmpp@ietf.org>; Mon, 7 Jan 2013 10:51:07 -0700 (MST)
Message-ID: <50EB09E2.7020501@stpeter.im>
Date: Mon, 07 Jan 2013 10:46:10 -0700
From: Peter Saint-Andre <stpeter@stpeter.im>
User-Agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10.7; rv:17.0) Gecko/17.0 Thunderbird/17.0
MIME-Version: 1.0
To: XMPP Working Group <xmpp@ietf.org>
X-Enigmail-Version: 1.4.6
Content-Type: text/plain; charset="UTF-8"
Content-Transfer-Encoding: 7bit
Subject: [xmpp] DNA prooftypes: advertising support and preference order?
X-BeenThere: xmpp@ietf.org
X-Mailman-Version: 2.1.12
Precedence: list
List-Id: XMPP Working Group <xmpp.ietf.org>
List-Unsubscribe: <https://www.ietf.org/mailman/options/xmpp>, <mailto:xmpp-request@ietf.org?subject=unsubscribe>
List-Archive: <http://www.ietf.org/mail-archive/web/xmpp>
List-Post: <mailto:xmpp@ietf.org>
List-Help: <mailto:xmpp-request@ietf.org?subject=help>
List-Subscribe: <https://www.ietf.org/mailman/listinfo/xmpp>, <mailto:xmpp-request@ietf.org?subject=subscribe>
X-List-Received-Date: Mon, 07 Jan 2013 17:46:05 -0000
-----BEGIN PGP SIGNED MESSAGE----- Hash: SHA1 Currently in DNA (draft-saintandre-xmpp-dna, recently expired but soon to be updated), there is no way for the receiving server or the connecting client / peer server to advertise the prooftypes it supports, or its preference order for prooftypes. This means it is possible that: (1) the set of mutually supported prooftypes might be null (in which case a connection attempt might be futile, depending on local security policies) (2) "expensive" prooftypes might be tried too early in the process (in which case the connecting client / peer server might spend time more trying to connect than necessary). My co-author and I chatted about this last week. Our rough sense is that we won't have enough prooftypes for this to be a significant concern, that the cost of adding and supporting more protocol (e.g., stream features) here isn't worth the potential benefit, that conventions regarding the prooftypes that need to be supported will emerge naturally in the relatively small market of XMPP systems needing DNA (mostly, large hosting providers), and that initiating entities can support an algorithm similar to "happy eyeballs" (RFC 6555) in order to speed up the connection process. If you disagree with our conclusions, do feel free to say so on the list. :) We *might* add some text about several of these topics in the next version of the spec, but most likely such text would be relegated to implementation and deployment notes or an informational appendix. Peter - -- Peter Saint-Andre https://stpeter.im/ -----BEGIN PGP SIGNATURE----- Version: GnuPG/MacGPG2 v2.0.18 (Darwin) Comment: Using GnuPG with undefined - http://www.enigmail.net/ iEYEARECAAYFAlDrCeEACgkQNL8k5A2w/vz8sgCfXOJs5WOq7IFwojqyQBXAltNF oWAAoL2o8qPwS8Qp8lPI5IqTuchsoJgo =oork -----END PGP SIGNATURE-----
- [xmpp] DNA prooftypes: advertising support and pr… Peter Saint-Andre