Set the AuthenticationResult via a new feature on the HttpContext

[davidfowl]

Today the authentication middleware resolved the AuthenticateResult for the current request/endpoint and stores the Principal on the HttpContext but doesn't store the other properties (Ticket, or AuthenticationProperties). Getting at these requires another call to AuthenticateAsync with the right scheme which can be a pain to get at. We should make this available via a feature on the HttpContext

cc @Tratcher @HaoK

[blowdart]

Could this be the result be extended out to give people that feature they want to return reasons from policies?

[HaoK]

We could do something similar for the authz middleware, but what would it be, like the result of the last authorization failure?

[blowdart]

Well you know there have been lots of requests for this sort of thing, including allowing information on why a policy failed, which mixes authn and authz in a way we don't like, but if this could be used it might make a lot of people happy.

[HaoK]

This isn't likely to be what you are looking for as it really only maps to the default authenticate call we do in the auth middleware

[blowdart]

Darn it :(

[analogrelay]

Is this servers? Feels more like security. Moving it for now.

[blowdart]

Told ya :) #21116