[Doh] POST and GET

[Sebastiaan Deckers <[e-mail]>]

Draft 14, 4.1. The HTTP Request:

> DoH servers MUST implement both the POST and GET methods.

What is meant by the word "implement"?

I have *implemented* both GET and POST code paths. But do they need to
exposed in every use case? I want to be able to support GET only for server
push, for example, and otherwise restrict client requests to POST.

GET requires much more processing from a DOH proxy. I.e. parse the DNS
response packet to find the lowest TTL for HTTP cache-control header
max-age. As an operator I may want to disable support for GET requests from
the client and return 405 or 501.

I love the idea of pushing DNS responses as GET. This is lightweight and
can be easily injected by a DOH proxy. However the current draft, in
section 5.3, does not impose a similar "MUST implement both" requirement on
the client. Should it?

Seb