How to configure AAA server and hostapd to support Hotspot 2.0 / Passpoint?

I am trying to setup an independent Hotspot 2.0 network. I am using TP-Link Archer C7 v2 routers as accesspoint.

I built and flashed Openwrt 15.05 on router. Built hostapd from source with HS20 and interworking options available. I am able to see that beacon frames has HS20 and interworking capabilities.

How can I authenticate clients coected to AP? Do I need to run some kind of server ruing. What configuration I need to do on AP and server side?