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

Alessandro Vesely <vesely@tana.it> Thu, 31 December 2020 16:35 UTC

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From: Alessandro Vesely <vesely@tana.it>
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Subject: Re: [dmarc-ietf] Ticket #42 - Expand DMARC reporting URI functionality
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On Thu 31/Dec/2020 16:37:38 +0100 John R Levine wrote:
> On Thu, 31 Dec 2020, Alessandro Vesely wrote:
> 
>> On Wed 30/Dec/2020 22:23:20 +0100 John R Levine wrote:
>>> [ add ruap= to allow https in preference to mailto ]
>>
>> I still like better sticking to a unique tag (rua=) and applying OR-slashes. 
>> With a comma, it is backward compatible:
>>
>> v=DMARC1; p=none; rua=mailto:local@example.com, mailto:report@service.example, /https://service.example/report/;
> 
> No, it's invalid according to the syntax in RFC 7489.


I see.  We have:

     dmarc-auri      = "rua" *WSP "=" *WSP
                        dmarc-uri *(*WSP "," *WSP dmarc-uri)

     URI             = scheme ":" hier-part [ "?" query ] [ "#" fragment ]

     scheme      = ALPHA *( ALPHA / DIGIT / "+" / "-" / "." )

So /https cannot be a scheme.  How about:

     v=DMARC1; p=none; rua=mailto:local@example.com, mailto:report@service.example, OR-https://service.example/report/;


> We have no idea what existing implementations do with DMARC records with syntax errors.
> 
> Here's an experiment -- put that slash syntax in the rua= in your DMARC record 
> and see who does or doesn't continue sending reports.


Done, with the second alternative.


Best
Ale
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