MSSQL Server licensing

[CreativeXtent]

Hey everyone.

Quick question, this seemed like the best spot.

Now... i am running a ASP.net web application.
Its back end is a MSSQL server.

There is only 1 MSSQL user/pass that is used to connect to authenticate users for our application ( like a forum does )

We have open free registration, and they can add 100+ users under their company usernames.

Do i need CAL's per user in my web application? or the multi core licensing ? Or does the one engine install with 1 user surface legally for this?

Btw this is for SQL server 2012