Really Using OpenSSO with Salesforce
This subject has been covered many times before, but one thing that is not easily identified in ANY of them is that for this to work properly, you must be using a version of OpenSSO express, not enterprise. You’ll bang your head against a rock looking for a solution.
The problem is that OpenSSO express doesn’t exist anymore. Well not in a form supported/provided by Oracle. ForgeRock now has it and it’s been rebranded to OpenAM. The good news is that all of these tutorials and documents still are valid — so long as you actually got the right piece of software.
I wish that when folks write documentation they include specifics about the software they are writing about. But then again, maybe it’s just me…