Migration from legacy authentication to EJB

Hi there,
I am a newbie of EJB. I have a question.
We have backend access based legacy authentication before the
business data access. If I understand correctly, EJB use role
based security and it's not related to the bean coding, which means
the business logic in bean knows nothing about security and it is
supposed to be trusted. My question is how to map the function of
the old authentication to the EJB model?
Thanks in advance.

There is something called Java connectivity architecture(JCA) that can take care of this issue.
You may have to write a connector to take care of accessing the legacy authenticator from your EJB.
I think there should be a software provider who can sell that off the shelf(compared to reinventing the wheel) depending on which legacy system you are trying to access.
Kishore.