Re: [Anima] New Version of draft-eckert-anima-grasp-dnssd

[Brian E Carpenter <[e-mail]>]

Steffen,

On 18-Jul-23 00:46, Fries, Steffen wrote:
> Hi,
> 
> I've read the latest version of draft-eckert-anima-grasp-dnssd-05 (https://datatracker.ietf.org/doc/draft-eckert-anima-grasp-dnssd/ <https://datatracker.ietf.org/doc/draft-eckert-anima-grasp-dnssd/>), which has been updated just recently. It targets provisioning of service discovery information similar as mDNS but solely relying on GRASP. This approach seems appropriate in setups in which mDNS is not intended to be used.
> 
> It specifically considers the mapping of TXT params, which may be leveraged also in the current discussion of discovery of BRSKI registrars with enhanced feature sets. Here, the intention is, to provide additional TXT params to describe specific services a registrar may offer, like a different enrollment protocol or support for alternative voucher encodings. While this functionality is discussed in the context of mDNS (for BRSKI-PRM), it can easily be mapped to GRASP using the described approach.
> 
> That said, I'm not really deep in GRASP, but I think if we currently discuss service discovery options using mDNS to detect enhanced feature sets for BRSKI registrars, it would be equally important to have this opportunity also for ANIs using GRASP instead of mDNS to enable a more specific discovery of registrars.
> 
> Toerless, will it be discussed in the IETF 117 ANIMA session?

I can't answer that, but note that the AN_Proxy and AN_join_registrar
GRASP objectives defined in RFC 8995 include an objective-value field.
For AN_Proxy that field is "any" so is currently undefined and could
be extended in any way we want. For AN_join_registrar it is defined as

objective-value = text       ; name of the (list of) supported
                              ; protocols: "EST-TLS" for RFC 7030.

I find that "(list of)" a bit unclear but again there is flexibility
to extend the semantics as we want. In fact that "(list of)" is almost
worth an errata, since I wouldn't know what to write in a program
to implement it.

Regards,
    Brian