RE: [saml-dev] Use of Provider ID in Redirect-Artifact Profile

["Scott Cantor" <cantor.2@osu.edu>]

> True. Just that it is not desired in our case to have such arrangement
that 
> requires SP and IdP to exchange such info apriori. All discovery is based
on 
> XRI Resolution.

You still need the XRI, and an XRI can be expressed as a URI, right? So make
that your providerId and hash that.

There's nothing wrong with doing metadata resolution via XRI, but you still
need the XRI to start with, and you cannot get it through SAML in band.
Extending the Artifact binding is not a viable strategy if you expect to
interoperate.

-- Scott