Additional external Authentification

Hi everybody,

I want to integrate an additional authentification. The User has to enter the Username (prepaid Ticket) and his mobile phone number. An SMS with an Authentification-Code (not the password) will be sent via SMS.

All users (abount 1200) are stored in the User-Manager-DB.

Any idea, how to realise that?
Can I access the User-Manager-Radius-Server via external PHP-Script?

Regards,
Philipp