In this blog post I want to clarify a point of initial confusion some people experience with OAM Federation 18.104.22.168. If we go to the “Federation” tab of the OAM Console, we see:
Now the two main objects you manage in your OAM Fed configuration are your IdP Partner definitions and your SP Partner definitions. So, I want to look at the IdP Partner definitions. Which link do I choose? The answer is, “Service Provider Management”. Conversely, to look at the SP Partner definitions, I click on “Identity Provider Management”. To many people, that at first seems back-to-front, but if you think about it some more, it makes perfect sense.
Let’s draw a diagram:
Each Service Provider has a relationship with one or more Identity Providers, and each Identity Provider has a relationship with one or more Service Providers. The owner of each Service Provider has to decide which Identity Providers it is willing to work with, and the owner of each Identity Provider has to decide which Service Providers it is willing to work with. Each of these IdP-SP relations can only exist by mutual agreement of both ends; each side is trusting the other – the service provider needs to trust the identity provider to provide genuine user identities (i.e. only authenticate email@example.com if it really is Joe); the identity provider needs to trust the service provider not to abuse the identities it is sent (e.g. to maintain the confidentiality of the user attribute data it is sent).
So the most important thing each IdP needs to know is – which SPs am I authorised to talk to? And the most important thing each SP needs to know is — which IdP am I authorized to talk to? So the SP Partners are part of the IdP configuration, and the IdP Partners are part of the SP configuration.