On Wed, Sep 20, 2023 at 12:33 AM Patrik Fältström <paf@xxxxxxxxxx> wrote:
> 19 sep. 2023 kl. 21:22 skrev Phillip Hallam-Baker <phill@xxxxxxxxxxxxxxx>:
>
> URI doesn't have quite the flexibility of SRV + TXT though.
A TXT that is what it is, raw data without any context?
Of course data without any constraints has more flexibility than typed data, but why?
RFC 6763 has been deployed for over a decade now. It is how most services that are using the DNS for discovery in a coherent fashion are doing it.
What I propose going forward is:
1) Recognize that RFC 6763 is the deployed base
2) Write a BIS to make interactions with SRV and .well-known explicit and make appropriate recommendations to DNS services
3) Write 'Web Services over QUIC' to replace use of HTTPS in which the .well-known tag is a first class object.
These all seem pretty obvious to me. I have been involved in HTTP and Web Services from the very start and there is really very little that HTTP/3 is delivering to generic Web Services that can't be provided better by going to raw QUIC with a minimal framing scheme.
As for the advantage of using prefixed TXT over a structured DNS record, the only difference is where parsing of a tag-value pair list takes place. Deployed code complying with RFC 6763 says it is in the client only.
I don't see the need for a lot of information in the TXT record but it is definitely an open set, not a closed one. Today I have
* The public key of the host to allow encryption of the initial hello message.
* The supported protocol version and options
* The required/supported security enhancements.
It is still possible for the service to return the SRV and TXT record in a single UDP packet.
I have even got a form of geographic based discovery to work within that framework. Assume that the DNS resolver understands these extensions
Alice makes a DNS query for _protocol.example.com GEO
There is no associated RR, the resolver replaces this with a query for
_<ASN>._protocol.example.com GEO
The response to this is signed SRV record(s) specifying the best hosts to service that ASN.
No additional TXT required.
