Client wants to set up a DNS server that will identify the requesting user, consult a database to verify that the user is permitted and depending if allowed, then return the correct IP else if not allowed, then redirect to our own IP where the server will block the user with a password screen. When successful password is entered, then the user is redirected to view the content.
We need only a small portion of this developed. We need the DNS service to listen on port 53, and instead of responding with configuration from static files, it will consult an API passing the hostname and user identification. The API is written in PHP, and can respond with JSON or XML.
The DNS server will be hosted on a dedicated VM on Amazon AWS EC2.
Please discuss your proposed solution with me.