IdP-initiated SSO on Version3

[Peter Schober]

* Yantis, Walt <wyantis at txstate.edu> [2016-03-31 16:34]:
> Now, we're trying to use the endpoint on our IDP for this, but get an error in our logs when using it.
> 
> Endpoint:  https://penelope.tr.txstate.edu/idp/profile/SAML2/Unsolicited/SSO?providerID=https://www.successfactors.com/C0000208269T1

Fyi, to be fully correct you'll have to urlencode any query parameters
(the URL here), but your issue is:

> Shibboleth Authentication Request message did not contain the
> providerId query parameter.

providerID != providerId.

-peter