Re: [dmarc-ietf] DMARC PSD and non-existent subdomains

[Hector Santos <[e-mail]>]

On 6/11/2019 11:38 AM, Alessandro Vesely wrote:
> On Tue 11/Jun/2019 00:41:16 +0200 Scott Kitterman wrote:
>> On Monday, June 10, 2019 8:07:25 AM EDT Richard C wrote:
>>
>>> Presumably other PSDs that aren’t brand new will have this problem too? I’m
>>> interested to hear whether we’re on our own or not.
>>
>> As written, DMARC (RFC 7489) has the option to express different policy for
>> subdomains (sp= tag).  Perhaps we could address this case in PSD DMARC by
>> leveraging that feature.
>>
>> PSD DMARC is the first time there is any DMARC related explicit guidance on
>> non-existent sub-domains.  If we made it a rule that non-existent sub-domains
>> use the domain level (p=) policy and existent sub-domains use the sub-domain
>> policy (sp=) then I believe the affect you are after is achievable.
>
>
> Rather than altering p= and sp=, I'd add an np=, say, for non-existing domains:
>
> * It certainly would gather more attention by implementers,
>
> * Domain owners could monitor <policy_published> to check it.
>
> * It allows the main domain to have a non-reject policy.

+1. I like this.

In general, I want compatibility, but it seems, in my opinion, to be a 
lack of willingness to consider more tags.  Maybe it is a messenger 
problem, but we long had quite a number of extended ideas for a 
standard DKIM Policy protocol framework. The Domain Discovery Lookup 
Method is one of them and its directly and indirectly related to 3rd 
party policy concepts, one that is defined by some public suffix list 
where I am not familiar with, appears to had politics involved too, 
and off hand, it appears to have a trust factor.  Can I trust using 
this list? Where do I get this list? Is there are periodic update 
concept and so forth.

I will place my trust on the cogs with this, but at this point, I will 
note I am lost with the extended logic algorithm being proposed. 
Trying the fast read the draft specs does not help. Maybe Scott can 
describe it (extended Lookup method) in pseudo code.


-- 
HLS