Re: [dmarc-ietf] Ticket #42 - Expand DMARC reporting URI functionality

Alessandro Vesely <vesely@tana.it> Mon, 25 January 2021 19:51 UTC

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To: John Levine <johnl@taugh.com>, dmarc@ietf.org
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From: Alessandro Vesely <vesely@tana.it>
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Date: Mon, 25 Jan 2021 20:51:43 +0100
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Subject: Re: [dmarc-ietf] Ticket #42 - Expand DMARC reporting URI functionality
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On Sun 24/Jan/2021 19:46:58 +0100 John Levine wrote:
> Here's a concrete proposal for https reporting:
> 
> In draft-ietf-dmarc-aggregate-reporting, in the transport section,
> between Email and Other Methods add:
> 
> Https POST
> 
> The message is an XML file with GZIP compression, sent with an https POST message
> to the given URI as media type application/gzip.
> The data SHOULD contain the filename described in Email transport
> above as the filename in the gzip header. The filename helps recipient
> hosts recognize duplicate reports.
> 
> In draft-ietf-dmarc-dmarcbis section 6.3 under the rua tag, add:
> 
> If there is more than one URI in the value, the URIs are conceptually evaluated from
> left to right and each report is delivered to each URI in turn.
> If a delivery to an "https:" URI succeeds, any subsequent URIs that are not "https:" are ignored.
> This allows a report recipient to prefer https reports while falling back to mailto reports.


Good!  That's much better than any other idea we've been discussing.

Say an external URI overrides a mailto:"u" with a pair https:,mailto: and the 
https: succeeds.  Are mailto: URIs following "u" to be ignored?  Answering yes 
eases the job of a report generator, as it is enough to produce a report and a 
verified list of URIs.  Answering no may seem to ease the composition of DMARC 
records; otherwise one has to pay attention to put external URIs toward the 
end.  Some examples are needed anyway.

You'll have to revert the order in your DMARC record.

Best
Ale
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