Re: [dmarc-ietf] ARC questions

John Levine <johnl@taugh.com> Sun, 22 November 2020 20:01 UTC

Return-Path: <johnl@iecc.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 5B5C93A0BEF for <dmarc@ietfa.amsl.com>; Sun, 22 Nov 2020 12:01:22 -0800 (PST)
X-Virus-Scanned: amavisd-new at amsl.com
X-Spam-Flag: NO
X-Spam-Score: 0.049
X-Spam-Level:
X-Spam-Status: No, score=0.049 tagged_above=-999 required=5 tests=[DKIM_SIGNED=0.1, DKIM_VALID=-0.1, DKIM_VALID_AU=-0.1, DKIM_VALID_EF=-0.1, HEADER_FROM_DIFFERENT_DOMAINS=0.249, SPF_PASS=-0.001, URIBL_BLOCKED=0.001] autolearn=ham autolearn_force=no
Authentication-Results: ietfa.amsl.com (amavisd-new); dkim=pass (2048-bit key) header.d=iecc.com header.b=CN6Ib+ne; dkim=pass (2048-bit key) header.d=taugh.com header.b=c5lH3PeI
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 BQPqILKvulrV for <dmarc@ietfa.amsl.com>; Sun, 22 Nov 2020 12:01:21 -0800 (PST)
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 C554A3A0BEE for <dmarc@ietf.org>; Sun, 22 Nov 2020 12:01:20 -0800 (PST)
Received: (qmail 25039 invoked from network); 22 Nov 2020 20:01:19 -0000
DKIM-Signature: v=1; a=rsa-sha256; c=simple; d=iecc.com; h=date:message-id:from:to:cc:subject:in-reply-to:mime-version:content-type:content-transfer-encoding:cleverness; s=61cd.5fbac38f.k2011; bh=d0qGUJckjv9uauW9cT/I9D6D9Q+5Yz3ApJSInNtv6L4=; b=CN6Ib+neNrGpGXTp9BJXb2N+Hov4Cl7/a6TMj3VmFg25Pvv+8EC8ihjojckn1o7qqKKPaEW7ajUsC03hj3U6ieae32is80UhxS2i4lDMrRpy1RKMXWqc7u8DqzBb/ms6Im2eUVw/f2BKCQHSLUe9AgLv6PL9WchkNrgHrIrQsO8Q9nWlSn6p+muAA3yeiMbMVjWrqqvN8BJXKJuFdDfxDsZeYHs5AsGf7rlFPUBgdgFwgcm9gf2QjOawkyATislarvCMZoF3+hv4+tmY/Y0BOco5LR4gSzgzlBkTxHRo2IdARgq/3JrXmXiONuEWRvv15J1vHmaaXPPtmu3Ob3JsLA==
DKIM-Signature: v=1; a=rsa-sha256; c=simple; d=taugh.com; h=date:message-id:from:to:cc:subject:in-reply-to:mime-version:content-type:content-transfer-encoding:cleverness; s=61cd.5fbac38f.k2011; bh=d0qGUJckjv9uauW9cT/I9D6D9Q+5Yz3ApJSInNtv6L4=; b=c5lH3PeI0PLHws4g/pwxU2D75SUNsnm8XmaHVAunA5A7DA4ec5vLvCILGrja6JEDouVih55aUrjjMtV/lm0Dp5nt0siCRX+sVbDUGRe2+MSrjG7PlLXC8lK82gF83YuileWesxNubeX1k9EZjEHQNfBtfHXbrjrcbgjuttHPI3SdvsczqtTxS6yPJENdtQXz9h161p5pyHNoliceRa9Ywix3lVp9dRIhZGU/sLoaBMN9NV8rIU0dMEIDvdxBfNjkFLP2YN6nohDgvnzJXk9fWfSImCsjR+J66zryBxDxPmUIHXOkUDuU96snKCT8G8RWPaeJCnEwlFVocpLDu8QkoA==
Received: from ary.qy ([IPv6:2001:470:1f07:1126::78:696d:6170]) by imap.iecc.com ([IPv6:2001:470:1f07:1126::78:696d:6170]) with ESMTPS (TLS1.2 ECDHE-RSA AES-256-GCM AEAD) via TCP6; 22 Nov 2020 20:01:19 -0000
Received: by ary.qy (Postfix, from userid 501) id 1D77527BB031; Sun, 22 Nov 2020 15:01:18 -0500 (EST)
Date: 22 Nov 2020 15:01:18 -0500
Message-Id: <20201122200119.1D77527BB031@ary.qy>
From: "John Levine" <johnl@taugh.com>
To: dmarc@ietf.org
Cc: mike@mtcc.com
In-Reply-To: <bb13f0db-362b-78dd-c005-279ac1776672@mtcc.com>
Organization: Taughannock Networks
X-Headerized: yes
Cleverness: minimal
Mime-Version: 1.0
Content-type: text/plain; charset=utf-8
Content-transfer-encoding: 8bit
Archived-At: <https://mailarchive.ietf.org/arch/msg/dmarc/IB67Wi1R1xAiybgcjOIsSSBq0y4>
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: Sun, 22 Nov 2020 20:01:22 -0000

In article <bb13f0db-362b-78dd-c005-279ac1776672@mtcc.com> you write:
>-=-=-=-=-=-
>
>
>On 11/22/20 11:18 AM, Douglas E. Foster wrote:
>> ARC has a very limited set of items included in the signature.� �Body 
>> hash is purposefully excluded.� So it is the same signature algorithm 
>> but with different parameters and a different purpose.� Therefore it 
>> has a different header label .
>
>Now wait, Kurt just said that the body hash is included. Somebody has to 
>be wrong here.

Doug is mistaken. The ARC-Message-Signature (AMS) header has the same
body hash as a DKIM signature.