Auth0 SAML service provider integration with shibboleth service provider

[Peter Schober]

Kannan, Satheesh (ELS-CON) via users <users at shibboleth.net> [2024-03-21 13:56 CET]:
> Is there a possibility of communication between two SAML service
> providers?

I don't recall having seen anyting in the SAML spec about an SP
receiving an authentication request.

> How to forward the saml assertion from shibboleth service provider to auth0 service provider?
> 
> For example, please look at the customer journey.

Instead of detailing how you want your hypothetical solution to work
why not start by describing the problem you want to solve?

Is this about sparing the subject from having to go through IDP
discovery for each SP? Modern SAML DS implementations such as
SeamlessAccess.org should make that a non-issue.

The only other thing I can think of that would somewhat match your
solution description would be making your "SP2" system into a SAML
proxy, meaning it would be an IDP towards your "SP1" and an SP towards
the chosen IDP.

-peter