Fwd: Two-Factor Authentication support in GNU RADIUS server

Hi,

We are trying to test two-factor authentication using RADIUS server.

*Two-Factor Authentication:*
            * First level authentication using username/password
            * Second level authentication using the OTP

*RADIUS FLOW:*

*User*                                              *NAS*
         *RADIUS server*
Telnet/SSH to NAS
using Username &  -------->   ACCESS-REQUEST  -----------> Authenticates
Username & password
password

Prompt the user
for OTP input       <--------------------           <-----------------
ACCESS-CHALLENGE

User enters OTP   -------->   ACCESS-REQUEST       ----------->
Authenticates OTP via external OTP verification script

User logs in
successfully       <--------------------           <-----------------
ACCESS-ACCEPT

Could you please confirm whether this RADIUS flow (two-factor
authentication) is feasible using GNU RADIUS server for PAP & CHAP users.


Regards,
Rajeesh.R