Send Upstream entityId to SP

[Cantor, Scott]

>    I need to return to the SP in the saml Response message the upstream
> idp entityId that performs the authorization.
>    Can someone guide me how to do it?

It already should by default, it's in the defined place for it in the standard, the AuthenticatingAuthority element. I don't have the schema in front of me, my recollection is that it's inside the AuthnContext element.

-- Scott