Use Oauth SAML Grant Type

How to connect to underlying data sources on behalf of Oauth when user comes into webservice with Oauth?
Use cases:
1 – client u/p sources: oauth/saml
2- client : oauth/saml sorces u/p, other
3 – client: Oauth/saml sources Oauth/saml (data sources are also secured by Oauth) –
3a) propogate sources and 3b – resolve new tokens for sources

Link: http://www.layer7tech.com/tutorials/oauth-20-with-layer-7-gateways-tutorial-4-the-saml-grant-type