first of all, this group is possibly not well suited for my question.
If so, please apologize and point me to a different target.

We have developed a web application for a customer which has a PKI
infrastructure implemented. Basically, the customer has configured its
BEA to provide an instance of Principal which we are using for
authorization purposes.

In order to simulate this settings, I would like to configure my
default realm for basic authentication. I understand that I should
also change the security model from "DDonly" to
"CustomRolesAndPolicies". However, when I visit my deployments
configuration page, I cannot find a possibility to change the security
model, even in "Lock & Edit" mode.

Any hints what's wrong?