For the best security and user experience, you'll probably want to go with the secured directory approach to determine that all files can only be accessed by authorized users.
Only thing I'm not sure of is how the mod_auth_cas and your JVM application engine (e.g. Tomcat) will interact. You might want to consider the Java WebApp CAS filter / authentication code instead.
This should make writing your own JForum SSO implimenation easy. Just use the request object's getPrincipal() method to determine who the user is.
The hard part is the need for jForum to know more about the user than just his/her netId. You will have to figure out what basic information can be set by defaults and/or needs to come from another source. One quick option is to check if this is the first time a user has connected and redirect them to a "please supply this info" form.
Also, it will be complex if you want to try to map CAS groups to Jforum groups for rights. It might be possible with a "CAS-ified" DAO implimentation. I'd suggest just using the normal jForum groups for various forum access control.
E.g., use CAS and CAS groups for the entry level access control, but jForum Groups which map to jForum Users that are based on CAS netIds for finer level access. [originally posted on jforum.net by monroe]
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