IETF Logo Mail Archive

Re: [dmarc-ietf] Ticket #1 - SPF alignment

Alessandro Vesely <vesely@tana.it> Wed, 27 January 2021 09:49 UTC

Return-Path: <vesely@tana.it>
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 DF76E3A0652 for <dmarc@ietfa.amsl.com>; Wed, 27 Jan 2021 01:49:06 -0800 (PST)
X-Virus-Scanned: amavisd-new at amsl.com
X-Spam-Flag: NO
X-Spam-Score: -2.121
X-Spam-Level:
X-Spam-Status: No, score=-2.121 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, NICE_REPLY_A=-0.001, RCVD_IN_MSPIKE_H3=-0.01, RCVD_IN_MSPIKE_WL=-0.01, SPF_PASS=-0.001, URIBL_BLOCKED=0.001] autolearn=ham autolearn_force=no
Authentication-Results: ietfa.amsl.com (amavisd-new); dkim=pass (1152-bit key) header.d=tana.it
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 1NB9RxhUk_J8 for <dmarc@ietfa.amsl.com>; Wed, 27 Jan 2021 01:49:05 -0800 (PST)
Received: from wmail.tana.it (wmail.tana.it [62.94.243.226]) (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 691EA3A0C4C for <dmarc@ietf.org>; Wed, 27 Jan 2021 01:49:05 -0800 (PST)
DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=tana.it; s=delta; t=1611740943; bh=bqOGGENUggyHmybo066Xqrbaqihwd0lJRP1gbZGRo+U=; l=2262; h=To:References:From:Date:In-Reply-To; b=DLqNYEn3nLgNseT6VjQ8pQMDOF8GsffnYWN18DIH2VvkKmMKSwdVSzGgVi8ePHF0u qhokCB+07bZ9NAPp12j5o82IbHR4vkzlEUJZXpWEGefI9biHi5Zh6rq/rHwfmloc+X XpIARfnP313urgDYqTSn+G+ShNXfvfpbpbzunk/ro2m5aimCGFFoQ0UDidp4W
Authentication-Results: tana.it; auth=pass (details omitted)
Original-From: Alessandro Vesely <vesely@tana.it>
Received: from [172.25.197.111] (pcale.tana [172.25.197.111]) (AUTH: CRAM-MD5 uXDGrn@SYT0/k, TLS: TLS1.3, 128bits, ECDHE_RSA_AES_128_GCM_SHA256) by wmail.tana.it with ESMTPSA id 00000000005DC09F.000000006011370F.00001E10; Wed, 27 Jan 2021 10:49:03 +0100
To: dmarc@ietf.org
References: <bef64e7a-571b-a73f-dc91-aa402ca320c8@taugh.com> <1859075.lZWC7Mh21l@zini-1880> <3ed1bd47-43e9-3260-b2fe-567c967eede2@tana.it> <1655426.E2olI3CrJK@zini-1880>
From: Alessandro Vesely <vesely@tana.it>
Message-ID: <c39916f8-33f5-9876-c018-53085f5cc8f5@tana.it>
Date: Wed, 27 Jan 2021 10:49:02 +0100
User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:78.0) Gecko/20100101 Thunderbird/78.6.0
MIME-Version: 1.0
In-Reply-To: <1655426.E2olI3CrJK@zini-1880>
Content-Type: text/plain; charset="us-ascii"; format="flowed"
Content-Language: en-US
Content-Transfer-Encoding: 7bit
Archived-At: <https://mailarchive.ietf.org/arch/msg/dmarc/FY14MkuV-q5OUpvFkw07MA1x_zM>
Subject: Re: [dmarc-ietf] Ticket #1 - SPF alignment
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: Wed, 27 Jan 2021 09:49:07 -0000

On Tue 26/Jan/2021 23:36:19 +0100 Scott Kitterman wrote:
> On Tuesday, January 26, 2021 11:47:51 AM EST Alessandro Vesely wrote:
>> On Tue 26/Jan/2021 14:14:45 +0100 Scott Kitterman wrote:
>>> On Tuesday, January 26, 2021 6:54:56 AM EST Alessandro Vesely wrote:
>>>> 
>>>> I doubt that SPF filters report envelope-from=postmaster@HELO; more 
>>>> likely they write helo=HELO.  In that case, the paragraph quoted above
>>>> is deceptive. >>>>
>>>>> I believe the proposed text is clear enough about not using
>>>>> separate HELO identity results and that's appropriate. >>>>
>>>> My filter collects SPF results recorded from an upstream SPF filter.
>>>> It writes Received-SPF: lines for each identity.  For NDNs, it writes
>>>> a Received-SPF: for the HELO identity only.  Am I allowed to use that 
>>>> result for DMARC? >>>
>>> No.  You should only use Mail From results.
>> 
>> So NDNs having only an aligned HELO will never pass DMARC?
>> 
>> And what is a <scope>helo</scope> element in aggregate reports provided for?
>> 
>> The spec says:
>> 
>>           [SPF] can authenticate either the domain that appears in the
>>     RFC5321.MailFrom (MAIL FROM) portion of [SMTP] or the RFC5321.EHLO/
>>     HELO domain, or both.
>> 
>> And then:
>> 
>>     In relaxed mode, the [SPF]-authenticated domain and RFC5322.From
>>     domain must have the same Organizational Domain.  In strict mode,
>>     only an exact DNS domain match is considered to produce Identifier
>>     Alignment.
>> 
>> So, consider the following message without DKIM signatures:
>> 
>> HELO example.org
>> MAIL FROM:<user@example.com>
>> 
>> Received-SPF: pass (domain example.org
>>    designates 192.0.2.1 as permitted sender)
>>    identity=helo; helo=example.org;
>> Received-SPF: fail (domain of user@example.com
>>    denies 192.0.2.1 as permitted sender)
>>    identity=mailfrom; envelope-from="user@example.com";
>> Subject: Not using a mail client for this example
>> From: different-user@example.org
>> 
>> Does it pass DMARC?
> 
> No.


Let's not be silly, Scott.  We have example.org as the SPF-authenticated domain 
and it is aligned with From:.  Are you saying that the message would pass if it 
had an empty bounce address, but since it can bounce it does not pass?!?


Best
Ale
--

v2.23.0 | Report a Bug | By Email