Re: [dane] email canonicalization for SMIMEA owner names

Alexey Melnikov <alexey.melnikov@isode.com> Fri, 12 December 2014 17:01 UTC

Return-Path: <alexey.melnikov@isode.com>
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 63C4D1A6FB8 for <dane@ietfa.amsl.com>; Fri, 12 Dec 2014 09:01:42 -0800 (PST)
X-Virus-Scanned: amavisd-new at amsl.com
X-Spam-Flag: NO
X-Spam-Score: -4.01
X-Spam-Level:
X-Spam-Status: No, score=-4.01 tagged_above=-999 required=5 tests=[BAYES_00=-1.9, DKIM_SIGNED=0.1, DKIM_VALID=-0.1, DKIM_VALID_AU=-0.1, GB_I_LETTER=-2, T_RP_MATCHES_RCVD=-0.01] 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 CNCHyFR3aeHB for <dane@ietfa.amsl.com>; Fri, 12 Dec 2014 09:01:40 -0800 (PST)
Received: from waldorf.isode.com (ext-bt.isode.com [217.34.220.158]) by ietfa.amsl.com (Postfix) with ESMTP id B9B271A6F96 for <dane@ietf.org>; Fri, 12 Dec 2014 09:01:40 -0800 (PST)
DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; t=1418403699; d=isode.com; s=selector; i=@isode.com; bh=4NQY7Xwu2WXaCr4XQntqDQnHZd8pmOzLuDbVl26oxHY=; h=From:Sender:Reply-To:Subject:Date:Message-ID:To:Cc:MIME-Version: In-Reply-To:References:Content-Type:Content-Transfer-Encoding: Content-ID:Content-Description; b=SbvLOcapLpGHaUJ4Qpu8f2JrLbmR0On4BrPx+6oFgEjhb6UImQ5KYORux0rJOrBVJg1NSm Aw+BqijbOAO5s5LJojvby2jZwYu2iMwDKxwc8GzAJw/DYjikJ8FIe+G8jg+hSmnWkKhRK2 ywcqslGhh2ryN1ADeZsQ7hn4iGNJei0=;
Received: from [172.20.1.215] (dhcp-215.isode.net [172.20.1.215]) by waldorf.isode.com (submission channel) via TCP with ESMTPSA id <VIsfcgBCk4Vg@waldorf.isode.com>; Fri, 12 Dec 2014 17:01:39 +0000
Message-ID: <548B1F62.5090002@isode.com>
Date: Fri, 12 Dec 2014 17:01:22 +0000
From: Alexey Melnikov <alexey.melnikov@isode.com>
User-Agent: Mozilla/5.0 (Windows NT 6.1; WOW64; rv:31.0) Gecko/20100101 Thunderbird/31.2.0
To: Ben Laurie <benl@google.com>
References: <95826148-4F06-4942-87A4-2F6601BA0F90@nist.gov> <CABrd9SQ1umsP731hvghV92EL5y2P4i++ESyrvxUhJD==z=pKpw@mail.gmail.com> <F79847E4-C748-467F-ADA3-0DBCD5CFE697@nohats.ca> <548B1013.4090000@isode.com> <CABrd9SQt6gqt_hAUECY4GN5_xDamTLJJnPAZAT8vVnovH1MeBg@mail.gmail.com>
In-Reply-To: <CABrd9SQt6gqt_hAUECY4GN5_xDamTLJJnPAZAT8vVnovH1MeBg@mail.gmail.com>
MIME-Version: 1.0
Content-Type: text/plain; charset="utf-8"; format="flowed"
Content-Transfer-Encoding: 7bit
Archived-At: http://mailarchive.ietf.org/arch/msg/dane/ZNyp0_U6gfImLHAWFIoUV6pQrro
Cc: Paul Wouters <paul@nohats.ca>, 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 17:01:42 -0000

On 12/12/2014 16:28, Ben Laurie wrote:
> On 12 December 2014 at 15:56, Alexey Melnikov <alexey.melnikov@isode.com> wrote:
>> On 12/12/2014 15:38, Paul Wouters wrote:
>>> Whoever starts using variant email addresses should publish records for
>>> it? As John said, clients shouldn't start guessing addressing schemes used
>>> by others
>> +1. Nobody other than the final MTA/MDA knows that certain forms are
>> equivalent.
> True, but does not make your scheme workable.
Only publish canonical form or variants that were used for sending 
emails out?
>>> Sent from my iPhone
>>>
>>>> On Dec 12, 2014, at 06:37, Ben Laurie <benl@google.com> wrote:
>>>>
>>>>> On 11 December 2014 at 19:51, Rose, Scott W. <scott.rose@nist.gov>
>>>>> wrote:
>>>>> Realized the other action item I was assigned to from the interim
>>>>> meeting was email canonicalization for SMIMEA.  I believe it stems from
>>>>> Viktor Dukhovni's email to the endymail list:
>>>>> http://www.ietf.org/mail-archive/web/endymail/current/msg00134.html
>>>>>
>>>>> I was wondering if we can borrow a page from RFC 4034 Section 6.2 and
>>>>> include text in the draft Section 3, item 1 in the numbered list:
>>>>>
>>>>>       1.   The user name (the "left-hand side" of the email address,
>>>>> called
>>>>>         the "local-part" in the mail message format definition [RFC2822]
>>>>>         and the "local part" in the specification for internationalized
>>>>>         email [RFC6530]), is hashed using the SHA2-224 [RFC5754]
>>>>>         algorithm (with the hash being represented in its hexadecimal
>>>>>         representation, to become the left-most label in the prepared
>>>>>         domain name.  This does not include the "@" character that
>>>>>         separates the left and right sides of the email address.  The
>>>>>         string that is used for the local part is a Unicode string
>>>>>         encoded in UTF-8 **with all upper case letters converted to their
>>>>>         corresponding lower case letters where appropriate.**
>>>>>
>>>>>
>>>>> The text between the '**' is new.  The goal is to prevent a situation
>>>>> when the email address is "JRandom@example.com" and the SMIMEA is created
>>>>> using "jrandom" as the user name.   Would this be enough, or are there
>>>>> scripts where this would result in different or potentially conflicting
>>>>> owner names?
>>>> Speaking of canonicalisation:
>>>>
>>>> 1. What about X+Y@Z - for almost all MTAs, this is the same as X@Z.
>>>>
>>>> 2. What about GMail's a.b.c@gmail.com == abc@gmail.com ==
>>>> ab.c@gmail.com == a.bc@gmail.com?
>>