MSCHAPv2 followed by a smsotp authentication

[Thomas Glanzmann]

Hello,
I have a propiertary radius client which I want to authenticate against
freeradius the following way:

        - User types is username: directory\Administrator password:secret
        - Freeradius authenticates against active directory.

This already works

        - From the documentation of the propiertary radius client:

          After authenticating to RADIUS, you may get another prompt if
          the RADIUS server responded with a supported Access Challenge.
          Full generic RADIUS challenge/response is not supported, but a
          limited access challenge for a string token code is supported.

        - So now I want freeradius to send 'Access Challenge' and send a
          sms to the user (for that purpose I wrote a perl daemon which
          listens on a unix socket in order to talk to smsotp freeradius
          module)[1]. However nothing comes in.

I configured freeradius the following way:

sites-enabled/default:
authorize {
        smsotp
        mschap
}

authenticate {
        mschap
        Auth-Type smsotp {
                mschap
                smsotp
        }

        Auth-Type smsotp-reply {
                smsotp
        }
}

users:
DEFAULT     Auth-Type = smsotp

radius -X output here: http://thomas.glanzmann.de/tmp/radius-x.txt

[1] smsotpd: http://thomas.glanzmann.de/tmp/smsotpd.pl

And now my questions:

        - Is it possible to do a mschapv2 authentication followed by
          Access challenge in order to send out a sms with a one time
          password by configuring freeradius or do I need to code? Where
          do I find pointers? I read the source code of the smsotp and
          the rlm_example module, I get the basic idea that first the
          otp is generated and than it is checked, however I don't get
          how to configure freeradius to choose the codepath. I also
          don't get if it is possible to stack authentication methods in
          freeradius.

Cheers,
        Thomas