chilli + freeradius + opendirectory

[Massimiliano Tommasi]

Hi,
I'm moving step by step to get my system working...
My architecture is:
WEB.CLIENT<--->CHILLI(captive.portal)<--->FREERADIUS<--->OPENLDAP
My problem now is between chilli and opendirectory THRU freeradius.
Chilli supports chap or pap.
I'm not able to use chap because, it's not compatible with openldap and
I get as message error that I need a text-plain password.
I'm not sure that using pap, it could be working.
If I'm right, I'm able to convert the password to plain-text after
chilli and before radius..., or am I wronging?
Is there a way, I can authenticate my users from web-interface on
opendirectory thru FREERADIUS?

The other way could be kerberos but, if i have well understood, I'll get
the same problem.

Give me some help, please.

Regards,
Max