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

Alessandro Vesely <vesely@tana.it> Thu, 21 January 2021 09:24 UTC

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Subject: Re: [dmarc-ietf] Ticket #1 - SPF alignment
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On Tue 19/Jan/2021 22:26:09 +0100 Todd Herr wrote:
> Picking up the thread on another ticket that was brought before the group
> pre-holidays and has lain fallow since the end of 2020...
> 
> John Levine asserted that there wasn't a lot of strong opinion on the
> matter, and therefore we'd be leaving the spec as is, with the MAIL FROM
> SPF check the only one that matters for DMARC.
> 
> Ale replied, but I don't interpret his reply as challenging John's
> assertion.


The thread went off-topic w.r.t. the purpose of ticket #1.


> Can this ticket be closed?


I agree that the spec needs some text somewhere to counter the passage in 
Section 2.3 of RFC 7208.  This, methinks, is the intended semantics of the 
second paragraph of section 3.1.2 of dmarcbis:

OLD:
    Note that the RFC5321.HELO identity is not typically used in the
    context of DMARC (except when required to "fake" an otherwise null
    reverse-path), even though a "pure SPF" implementation according to
    [RFC7208] would check that identifier.

I'd rather replace that paragraph and leave item 4 of Section 6.6.2 as is.  For 
a possibly less confusing wording:

NEW:

    Even tough a "pure SPF" implementation, according to [RFC7208], would
    avoid to check the RFC5321.MailFrom identity if the RFC5321.HELO was
    conclusively determined to pass, DMARC authentication requires the
    authenticated identity to be aligned.


Best
Ale
--