IETF Logo Mail Archive

Re: [dane] email canonicalization for SMIMEA owner names

Paul Wouters <paul@cypherpunks.ca> Fri, 12 December 2014 02:11 UTC

Return-Path: <paul@cypherpunks.ca>
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 535611A914D for <dane@ietfa.amsl.com>; Thu, 11 Dec 2014 18:11:46 -0800 (PST)
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 wErWpGUHswnF for <dane@ietfa.amsl.com>; Thu, 11 Dec 2014 18:11:44 -0800 (PST)
Received: from bofh.nohats.ca (bofh.nohats.ca [76.10.157.69]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by ietfa.amsl.com (Postfix) with ESMTPS id 9BA8D1A9106 for <dane@ietf.org>; Thu, 11 Dec 2014 18:11:44 -0800 (PST)
Received: from bofh.nohats.ca (bofh.nohats.ca [127.0.0.1]) by bofh.nohats.ca (Postfix) with ESMTP id 6FA0F80046; Thu, 11 Dec 2014 21:11:43 -0500 (EST)
Received: from localhost (paul@localhost) by bofh.nohats.ca (8.14.7/8.14.7/Submit) with ESMTP id sBC2BgKF023620; Thu, 11 Dec 2014 21:11:42 -0500
X-Authentication-Warning: bofh.nohats.ca: paul owned process doing -bs
Date: Thu, 11 Dec 2014 21:11:42 -0500
From: Paul Wouters <paul@cypherpunks.ca>
X-X-Sender: paul@bofh.nohats.ca
To: Nico Williams <nico@cryptonector.com>
In-Reply-To: <20141211221456.GI3448@localhost>
Message-ID: <alpine.LFD.2.10.1412112102170.23084@bofh.nohats.ca>
References: <95826148-4F06-4942-87A4-2F6601BA0F90@nist.gov> <20141211221456.GI3448@localhost>
User-Agent: Alpine 2.10 (LFD 1266 2009-07-14)
MIME-Version: 1.0
Content-Type: TEXT/PLAIN; format="flowed"; charset="US-ASCII"
Archived-At: http://mailarchive.ietf.org/arch/msg/dane/sAuS_Vgwegh_3cU1fhjTRCl-tGg
Cc: dane WG list <dane@ietf.org>
Subject: Re: [dane] email canonicalization for SMIMEA owner names
X-BeenThere: dane@ietf.org
X-Mailman-Version: 2.1.15
Precedence: list
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: Fri, 12 Dec 2014 02:11:46 -0000

On Thu, 11 Dec 2014, Nico Williams wrote:

> So maybe we need no canonicalization step at all.
>
> If I say I'm foo@bar.example, and you type Foo@bar.example into your
> MUA to send me e-mail, you might not reach me.
>
> That seems fair.

Actually, that is really stupid, seeing that many mobile phones, which
are hard to type on to begin with, auto-capitalize for many reasons. My
phone regularly corrects emails I forward to myself to Paul@nohats.ca.

No currently maintained implementation of email should support that these
two might be different local users.

> And allows for aliases of any kind.  If I want to
> publish SMIMEA RRs for all possible capitalizations of "foo"
> @bar.example, well I can, and if I don't want to then I don't have to.

A client can lookup the given name, if NXDOMAIN and not all lowercase,
lowercase it and try again.

And someone should write an RFC updating SMTP to not allow
case-sensitivity for different mailboxes so we can stop coming back to
this whenever anyone wants to do anything with email addresses.

Paul

v2.23.0 | Report a Bug | By Email