Build a system for authentication and authorization

["Truong Duc Luong" <ducluong.truong () cmctelecom vn>]

Hi list,

I have plan to setup servers to authenticate and authorize user access. The
server allow or disallow user access to one or some servers. If user are
permited, the server will set your permission on that server. For example,
we have 4 element:
- 1 Mail server (A) with ssh enabled
- 1 server (B) for authentication and authorization
- 1 user's PC.
PC ssh to A. A ask B that user's PC have access or no access permission. If
yes, user's PC log on to A. A ask B that what permission user can do.
Hope you understand my case.

How can I setup such system? I think we have solution somewhere? What
security I need to care about it?

Many Thanks.
Trudulu.