Re: [dmarc-ietf] Spirit of RFC8601 section 5 for invalid A-R headers

John R Levine <johnl@taugh.com> Fri, 03 April 2020 20:30 UTC

Return-Path: <johnl@taugh.com>
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 107DB3A0A45 for <dmarc@ietfa.amsl.com>; Fri, 3 Apr 2020 13:30:13 -0700 (PDT)
X-Virus-Scanned: amavisd-new at amsl.com
X-Spam-Flag: NO
X-Spam-Score: -2.1
X-Spam-Level:
X-Spam-Status: No, score=-2.1 tagged_above=-999 required=5 tests=[BAYES_00=-1.9, DKIM_SIGNED=0.1, DKIM_VALID=-0.1, DKIM_VALID_AU=-0.1, DKIM_VALID_EF=-0.1, SPF_PASS=-0.001, URIBL_BLOCKED=0.001] autolearn=ham autolearn_force=no
Authentication-Results: ietfa.amsl.com (amavisd-new); dkim=pass (1536-bit key) header.d=iecc.com header.b=h9pIxL2u; dkim=pass (1536-bit key) header.d=taugh.com header.b=TQsBXmL2
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 lFsEZ2UfxPpm for <dmarc@ietfa.amsl.com>; Fri, 3 Apr 2020 13:30:11 -0700 (PDT)
Received: from gal.iecc.com (gal.iecc.com [IPv6:2001:470:1f07:1126:0:43:6f73:7461]) (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 553B13A0A42 for <dmarc@ietf.org>; Fri, 3 Apr 2020 13:30:11 -0700 (PDT)
Received: (qmail 79685 invoked from network); 3 Apr 2020 20:30:10 -0000
DKIM-Signature: v=1; a=rsa-sha256; c=simple; d=iecc.com; h=date:message-id:from:to:cc:subject:in-reply-to:references:mime-version:content-type:user-agent; s=1373f.5e879cd2.k2004; i=johnl-iecc.com@submit.iecc.com; bh=bVI4QqtqZeE9rGwhZWkA8ehb4cUpau3n39dqNEo5RyE=; b=h9pIxL2uP1TiZM7DA2BVPAoYWMWSCqZBHQFEVcf7Y0H6TbDWpScgRYPZPMjW4DWvXE3Py/ErYhMtC+f/jX1/djn5CbIgwfpKFfyG7BEhXfsimfuH1S3jr5s7zlCF3Kl2x3N8Mol2IIgU1zlktNbLTKIo1KzYzXOXBTO0vF1SjxJv9hfHEN5+iU8D8z9uQjNwRMkcnRgOeAAONJbSBvkzC5pAjH7+K3YwOCiKTX5+1p9IJwVCYp3xn4gijAm15xJP
DKIM-Signature: v=1; a=rsa-sha256; c=simple; d=taugh.com; h=date:message-id:from:to:cc:subject:in-reply-to:references:mime-version:content-type:user-agent; s=1373f.5e879cd2.k2004; olt=johnl-iecc.com@submit.iecc.com; bh=bVI4QqtqZeE9rGwhZWkA8ehb4cUpau3n39dqNEo5RyE=; b=TQsBXmL25pOxMS//shFrzoaxcehXJOUKtelzHwKSZL+5Bk4M9irNf1WUuM35z1Y9el9jU9oADpWsKOgqOVoH37IaHcQirItJ4YVBaeHBRQLbiDHhSokTI5ND20/XRhG6RvESB9dLenF7Tzle12laRnq3znhVDJhz/T+EkjvD5DZcgGyzcflNC7DWEbQL17ujr9ohonMi9pjDtl6agaPsZl6nkOrg+28QrticeAsRvnKoLQTAArjXQUZ43lcfnXi0
Received: from localhost ([IPv6:2001:470:1f07:1126::78:696d:6170]) by imap.iecc.com ([IPv6:2001:470:1f07:1126::78:696d:6170]) with ESMTPSA (TLS1.3 ECDHE-RSA AES-256-GCM AEAD, johnl@iecc.com) via TCP6; 03 Apr 2020 20:30:09 -0000
Date: Fri, 03 Apr 2020 16:30:09 -0400
Message-ID: <alpine.OSX.2.22.407.2004031629030.42355@ary.qy>
From: John R Levine <johnl@taugh.com>
To: "Kurt Andersen (b)" <kboth@drkurt.com>
Cc: "dmarc@ietf.org" <dmarc@ietf.org>, Brandon Long <blong@google.com>
In-Reply-To: <CABuGu1okw4AD1tjEOe9GAJR+dpbTWB+RojKPZn7VatU1NXzCyg@mail.gmail.com>
References: <CABa8R6sbHLfkzHD4gaPBxQbgNy57J1eLXt2sPyAfaTYAY3tG-Q@mail.gmail.com> <20200403200937.AAFD716FCA1B@ary.qy> <CABuGu1okw4AD1tjEOe9GAJR+dpbTWB+RojKPZn7VatU1NXzCyg@mail.gmail.com>
User-Agent: Alpine 2.22 (OSX 407 2020-02-09)
MIME-Version: 1.0
Content-Type: text/plain; charset="US-ASCII"; format="flowed"
Archived-At: <https://mailarchive.ietf.org/arch/msg/dmarc/5cHp5FiTozwxp6fZyxAyJtxiQQM>
Subject: Re: [dmarc-ietf] Spirit of RFC8601 section 5 for invalid A-R headers
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: Fri, 03 Apr 2020 20:30:13 -0000

>>> In practice, I don't know how common it is for clients to consume this
>>> header.
>>
>> They have to if they're adding ARC seals on the way out.
>
> Only if the ADMD's particular implementation to pass through the
> information from incoming perimeter system to outgoing perimeter system
> happens to utilize the A-R header(s) for the purpose of conveying that
> information.

It would seem pretty perverse to create an AAR header with exactly the 
same info as the AR header by ignoring the AR header.  But whatever.

Regards,
John Levine, johnl@taugh.com, Taughannock Networks, Trumansburg NY
Please consider the environment before reading this e-mail. https://jl.ly