Use a specific IDP based on resource request query string

[Peter Schober]

* Simon Bright <simon.bright at e2bn.org> [2012-04-25 17:51]:
> We are currently configuring our web page(s) with logo'd IDP buttons
> for different providers and these buttons are coded with session
> initiiator urls see example below. 
> 
> https://passport.e2bn.org/Shibboleth.sso/Login?entityID=https://shibboleth-idp.webbased.co.uk/idp/shibboleth&target=https://passport.e2bn.org/secure .... etc 
> 
> These work fine but are not very user friendly if we want to tell
> other users how to build a button to get to our content from their
> own portal/web pages via SSO. 
> 
> What I'd like to do is make the coding for the urls more elegant for example 
> 
> https://passport.e2bn.org/secure/target/?idp=friendlyIdpname 
> 
> I'd like to use the Request Mapper to take this url and route the
> request to the appropriate idp entity ID based on the
> friendlyIdpname part , either directly or via a named dedicated
> session initiator within the shibboleth2.xml file 

Why not simply point those sites to a script of your own (outside the
Shib SP and outside a protected directory), where you can make up
request parameters and parse them and generate redirects to your
hearts content? I don't see the advantage letting the SP do this.

If you don't insist on generating what is referred to as NASCAR-style
IdP discovery you might want to look at the Shibboleth EDS or maybe
discojuice.org, both of which are modern discovery interfaces designed
with improved user experience and functional elegance in mind.

> Can I somehow use the Query Name function within the request mapper
> to do this , by linking a requireSessionWith (sessioninitiator) or
> by otherwise declaring the idp entity id to use.
> 
> The Request Mapper documentation seems to suggest this but I cannot
> find any examples.
> 
> Can you help by commenting if this is posible and if so how the
> Query Name part should be located and configured within the Request
> Mapper e.g does it go in the Access Control Part or outside it.

I obviously don't understand what you're up to, so bear with me:
Why is the request mapper and the way you require sessions relevant
here? If you hand out custom URLs that get rewritten to session
initiator requests there's no ShibRequireSession involved, no?
-peter