Dave Crocker wrote:
What MIME types does a recipient support?
What servers does a target host support?
With extremely few exceptions, Internet mechanisms do not support a
test-before-using model.
If I read your reply correctly, you would support such an initiative which
would advertise what else is available.
My main point was that the absence of similar mechanisms suggests that it
might be difficult to create one for this case.
Such mechanisms seem inherently useful, so their absence from 35 years of
operational effort implies the presence of some barriers.
Would you not consider the HELO response an example of such a mechanism?
It communicates what the abilities of the server are.
How about the Accept: and Accept-language: mechanisms in HTTP GET
requests? (they list the MIME types that the browser can handle and the
content languages that the user can understand, respectively)
The ssh credentials negotiation might be a good example also (where the
server advertises what methods are available):
Authentications that can continue: publickey, password, keyboard-interactive
There may be other such examples too.
Dave's idea was to also provide a mechanism for a domain to list what
authentication/authorization methods it supports?
I must have missed something? Please point it out if so.
Greetings,
Radu.