Re: [dmarc-ietf] ARC questions

Dave Crocker <dhc@dcrocker.net> Mon, 23 November 2020 19:34 UTC

Return-Path: <dhc@dcrocker.net>
X-Original-To: dmarc@ietfa.amsl.com
Delivered-To: dmarc@ietfa.amsl.com
Received: from localhost (localhost [127.0.0.1]) by ietfa.amsl.com (Postfix) with ESMTP id 9D6BE3A0CF8 for <dmarc@ietfa.amsl.com>; Mon, 23 Nov 2020 11:34:08 -0800 (PST)
X-Virus-Scanned: amavisd-new at amsl.com
X-Spam-Flag: NO
X-Spam-Score: -0.001
X-Spam-Level:
X-Spam-Status: No, score=-0.001 tagged_above=-999 required=5 tests=[NICE_REPLY_A=-0.001, SPF_PASS=-0.001, URIBL_BLOCKED=0.001] autolearn=unavailable autolearn_force=no
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 kzk59fh8jXmn for <dmarc@ietfa.amsl.com>; Mon, 23 Nov 2020 11:34:05 -0800 (PST)
Received: from simon.songbird.com (simon.songbird.com [72.52.113.5]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by ietfa.amsl.com (Postfix) with ESMTPS id 2988F3A0CFA for <dmarc@ietf.org>; Mon, 23 Nov 2020 11:34:05 -0800 (PST)
Received: from [192.168.0.109] (c-24-130-62-181.hsd1.ca.comcast.net [24.130.62.181]) (authenticated bits=0) by simon.songbird.com (8.14.4/8.14.4/Debian-4.1ubuntu1.1) with ESMTP id 0ANJbZ72026825 (version=TLSv1/SSLv3 cipher=AES128-GCM-SHA256 bits=128 verify=NOT); Mon, 23 Nov 2020 11:37:35 -0800
Reply-To: dcrocker@bbiw.net
To: Brandon Long <blong=40google.com@dmarc.ietf.org>, Michael Thomas <mike@mtcc.com>
Cc: "dmarc@ietf.org" <dmarc@ietf.org>, "Kurt Andersen (b)" <kboth@drkurt.com>, John R Levine <johnl@taugh.com>
References: <dcc265f9-a143-5093-eba0-94ee059c7cc7@mtcc.com> <20201122021417.B5E6E27B3E59@ary.qy> <CABuGu1pX=5ZC4RLsv19qrosRN9nCrPdeSk5Xg4O7ViEZit6dnA@mail.gmail.com> <453c4db4-fc62-dc76-5b15-707623d66f9f@mtcc.com> <64f18b-ae8-8c15-3d33-ff2d864c35bc@taugh.com> <884541e6-5076-7f8f-d1d2-d68ea9c5a2bc@mtcc.com> <CABa8R6u_K=KEQv3vmkVwEuYon350NEkd62eOovhq+gv9wonSnA@mail.gmail.com>
From: Dave Crocker <dhc@dcrocker.net>
Organization: Brandenburg InternetWorking
Message-ID: <f28b76e5-2855-985e-ece5-960aa68e2846@dcrocker.net>
Date: Mon, 23 Nov 2020 11:33:53 -0800
User-Agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:78.0) Gecko/20100101 Thunderbird/78.5.0
MIME-Version: 1.0
In-Reply-To: <CABa8R6u_K=KEQv3vmkVwEuYon350NEkd62eOovhq+gv9wonSnA@mail.gmail.com>
Content-Type: text/plain; charset=utf-8; format=flowed
Content-Language: en-US
Content-Transfer-Encoding: 7bit
Archived-At: <https://mailarchive.ietf.org/arch/msg/dmarc/0IyhdggapQSexV1mJqYeddGzSuY>
Subject: Re: [dmarc-ietf] ARC questions
X-BeenThere: dmarc@ietf.org
X-Mailman-Version: 2.1.29
Precedence: list
List-Id: "Domain-based Message Authentication, Reporting, and Compliance \(DMARC\)" <dmarc.ietf.org>
List-Unsubscribe: <https://www.ietf.org/mailman/options/dmarc>, <mailto:dmarc-request@ietf.org?subject=unsubscribe>
List-Archive: <https://mailarchive.ietf.org/arch/browse/dmarc/>
List-Post: <mailto:dmarc@ietf.org>
List-Help: <mailto:dmarc-request@ietf.org?subject=help>
List-Subscribe: <https://www.ietf.org/mailman/listinfo/dmarc>, <mailto:dmarc-request@ietf.org?subject=subscribe>
X-List-Received-Date: Mon, 23 Nov 2020 19:34:09 -0000

On 11/23/2020 11:29 AM, Brandon Long wrote:
> The DKIM-Signature is an "ownership" thing, it's a message originator 
> that is saying
> "associate this message to me".

That is not DKIM's semantics:

    "DomainKeys Identified Mail (DKIM) permits a person, role, or
    organization to claim some responsibility for a message by
    associating a domain name"

This says nothing about whether the organization has anything to do with 
origination.

There is nothing to prohibit or preclude handling agents other than the 
originator from signing.


> 
> Intermediaries don't want to take ownership of the message in that 
> sense, though there
> are some mailing lists that do.

Signing with DKIM does not take 'ownership'.



d/
-- 
Dave Crocker
Brandenburg InternetWorking
bbiw.net