Re: [Ietf-dkim] DKIM-Signature: r=y and MLM

"Murray S. Kucherawy" <superuser@gmail.com> Sat, 18 August 2018 22:02 UTC

Return-Path: <superuser@gmail.com>
X-Original-To: ietf-dkim@ietfa.amsl.com
Delivered-To: ietf-dkim@ietfa.amsl.com
Received: from localhost (localhost [127.0.0.1]) by ietfa.amsl.com (Postfix) with ESMTP id A3876130F23 for <ietf-dkim@ietfa.amsl.com>; Sat, 18 Aug 2018 15:02:40 -0700 (PDT)
X-Virus-Scanned: amavisd-new at amsl.com
X-Spam-Flag: NO
X-Spam-Score: -1.999
X-Spam-Level:
X-Spam-Status: No, score=-1.999 tagged_above=-999 required=5 tests=[BAYES_00=-1.9, DKIM_SIGNED=0.1, DKIM_VALID=-0.1, DKIM_VALID_AU=-0.1, FREEMAIL_FROM=0.001, HTML_MESSAGE=0.001, RCVD_IN_DNSWL_NONE=-0.0001, SPF_PASS=-0.001] autolearn=ham autolearn_force=no
Authentication-Results: ietfa.amsl.com (amavisd-new); dkim=pass (2048-bit key) header.d=gmail.com
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 xREt2yQK_7rj for <ietf-dkim@ietfa.amsl.com>; Sat, 18 Aug 2018 15:02:38 -0700 (PDT)
Received: from mail-lf1-x131.google.com (mail-lf1-x131.google.com [IPv6:2a00:1450:4864:20::131]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by ietfa.amsl.com (Postfix) with ESMTPS id 4D5B0130E07 for <Ietf-dkim@ietf.org>; Sat, 18 Aug 2018 15:02:38 -0700 (PDT)
Received: by mail-lf1-x131.google.com with SMTP id a4-v6so8298541lff.5 for <Ietf-dkim@ietf.org>; Sat, 18 Aug 2018 15:02:38 -0700 (PDT)
DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=mime-version:in-reply-to:references:from:date:message-id:subject:to :cc; bh=o7upeEBTn0NIEnj3t2IGkj6hx6nEfnuPmnOfH0tKyH4=; b=iGOaAaad7RrknkYsK7k+p+irKEjMzw1mgkIR8IuwWexj5z5aU4zipO0V5DEvwWqwQj gsO3jyNgsLErjCIuMRe0Tdz16AMXvMgtUz7BMA4YyZdt/093P49AASX5a+o31wQ1AJOd FYIzP1DSW+IBC3XLdD73rjhXjyIsmrAqqsseyX7vcqxqz0o87rnXzwMP65SABF/RR9fu yngJZMTI4cXL7zhArIdPz4vjGrKvGLNcUCAwa/9/VDrFKWuNWFdyTQVzCGc187LZxli+ ig/2fSS+lJ9+KXKu/sFmtMnw2DuiZ5mhnxm1ipvP8aZQqWKTaBnpBfEASkfBlDT4vL2Q NKFQ==
X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:mime-version:in-reply-to:references:from:date :message-id:subject:to:cc; bh=o7upeEBTn0NIEnj3t2IGkj6hx6nEfnuPmnOfH0tKyH4=; b=eqBzoHJe4DPzFMUYD6mf+2xtyX4AHLliUff2YxHlsgQBmacFXeVuxxjbnUBO0+j05A n+xvOeJTC2jeocOSuTybRCTc6gdOpBzoqeFNluadhMGt2dxAqehExEeuBXw6ABts9ZQZ Uw61ccLTlyzYLS02laTqwdIFQnBnVd6XYUa9EXz5GlToZU/wUb6HBWinnLUl7Fwp+Jw+ L9Aagrx+lwkeu8ZZAWG3yn4gYZ1akdmsmNOn/g8qyjy1Ij4lksdQhZFxpFaJSHncnWno FheiT3Jv04GT4zBr/hIyv7SJhXpqvwApVh1gAurhPlxn8H7SMflalLHFC1NIg6yu5ia/ tPFw==
X-Gm-Message-State: AOUpUlGPAMBsbFRwyP5yOSaL6n5wuQC6hkWdQmcC+xm/oy4emz1gOgSi 6X8s0Eheas0TZaYWNgWIoAgEbEGiMIm9oroDeJZNtw==
X-Google-Smtp-Source: AA+uWPxPgTelnusXgr8Vobf7zp+kn5xgrksC704mlHSaERPgLwKNukygNVXBXzLoi2Uv46B8MqGURwrfgkPugWEgvvQ=
X-Received: by 2002:a19:9710:: with SMTP id z16-v6mr26821418lfd.17.1534629756578; Sat, 18 Aug 2018 15:02:36 -0700 (PDT)
MIME-Version: 1.0
Received: by 2002:a2e:3a13:0:0:0:0:0 with HTTP; Sat, 18 Aug 2018 15:02:35 -0700 (PDT)
In-Reply-To: <20180811033840.Horde.i6llD-AtvgzyNIjbhTs-nkS@webmail.aegee.org>
References: <20180811033840.Horde.i6llD-AtvgzyNIjbhTs-nkS@webmail.aegee.org>
From: "Murray S. Kucherawy" <superuser@gmail.com>
Date: Sat, 18 Aug 2018 15:02:35 -0700
Message-ID: <CAL0qLwb=rBRit5XeUQA+73SjfyFx45KrpERgrrFSdbs6HjuNcw@mail.gmail.com>
To: Dilyan Palauzov <Dilyan.Palauzov@aegee.org>
Cc: Ietf-dkim@ietf.org
Content-Type: multipart/alternative; boundary="00000000000080b2830573bcd55e"
Archived-At: <https://mailarchive.ietf.org/arch/msg/ietf-dkim/pgkDgUUj-5t4YYf9wlYvJfzv0PU>
Subject: Re: [Ietf-dkim] DKIM-Signature: r=y and MLM
X-BeenThere: ietf-dkim@ietf.org
X-Mailman-Version: 2.1.27
Precedence: list
List-Id: IETF DKIM List <ietf-dkim.ietf.org>
List-Unsubscribe: <https://www.ietf.org/mailman/options/ietf-dkim>, <mailto:ietf-dkim-request@ietf.org?subject=unsubscribe>
List-Archive: <https://mailarchive.ietf.org/arch/browse/ietf-dkim/>
List-Post: <mailto:ietf-dkim@ietf.org>
List-Help: <mailto:ietf-dkim-request@ietf.org?subject=help>
List-Subscribe: <https://www.ietf.org/mailman/listinfo/ietf-dkim>, <mailto:ietf-dkim-request@ietf.org?subject=subscribe>
X-List-Received-Date: Sat, 18 Aug 2018 22:02:41 -0000

On Fri, Aug 10, 2018 at 8:38 PM, Dilyan Palauzov <Dilyan.Palauzov@aegee.org>;
wrote:

> I suggest here in to suggest in a more formal manner, that MLMs modifying
> a message are supposed to remove the r=y part of just invalidated
> DKIM-Signature and this logic is also applied for ARC, if relevant (I don't
> know ARC).  Fixing only ARC will not help, as there is software that
> follows DKIM, but has no idea about ARC.
>
> Is such a recommendation a good idea?
>
> How to make the recomentation?  Amendment to RFC6377, amendment to RFC
> 6651, something else, that is very short to compose?
>

I think advising anyone to alter a signature on a message irrespective of
the signature's validity will be hard to sell.  It would be simpler to just
remove the signature entirely if there's a good reason not to want it there
anymore.

This unfortunately seems a rather small thing for which to spin up an
update to either RFC6377 or RFC6651.  Are there any other things that have
evolved since those documents were published that might make revisions
worth doing?

-MSK