Copying response from Implementing authentication via CAS
Please take a look at https://listsprd.osu.edu/pipermail/ood-users/2017-November/000085.html and https://listsprd.osu.edu/pipermail/ood-users/2017-November/000086.html
If you need any more guidance I can reach out to sites I know that use CAS and see if they can post here.