Why would you want access to it in the Perl module? The "chap" module already does this.
Use the code that's already in the server?
*> Any thoughts on how to support the RFC?
Your Perl module should supply a Cleartext-Password to the server, and the server will Just Do the Right Thing.
If you're thinking of doing something else, I'd like to know why. Odds are it's overly complicated and unnecessary.
I didn't realize that is how it works, looking at: http://wiki.freeradius.org/Rlm_perl It seems like I need to do all the authentication and set the RAD_REPLY attributes. That does work except for my problem case, but what you are saying is all I have to do is return the clear text password, and freeradius will do the rest? I'm not seeing how to just return the clear text password from the wiki docs.