Federated Single Sign-on with Shibboleth

Shibboleth supports federated (i.e. multiple Identity Provider, IdP) Single Sign-on (SSO) with SAML 2.0.

Shibboleth 2 supports SAML 2.0 and WS-Federation Passive (ADFS), but NOT OAuth 2.0 and OpenID 2.

Reference:

1. https://shibboleth.net/about/
2. https://wiki.shibboleth.net/confluence/display/DEV/Supported+Protocols
3. https://wiki.shibboleth.net/confluence/display/SHIB2/NativeSPApacheConfig
4. https://wiki.shibboleth.net/confluence/display/SHIB2/SPReverseProxy