[Samba] ntlm_auth how to get challenge and nt-response

[Piviul]

Hi all, I'm trying to use ntlm_auth as authenticator of the freeradius 
mschap module. If I use ntlm_auth from command line with username and 
password, authentication works. If I use the same credentials with 
mschap on the logs I can see the challenge and nt-response and I can't 
understand if authentication fails because challenge and response are 
wrong or because ntlm_auth can't authenticate for a winbind/samba 
configuration problem.

Finally the question: how can I get valid challenge and nt-response 
strings to pass to ntlm_auth to see if ntlm auth works using challenge 
and nt-response options?

Can you please tell me some trick to debug the problem?

Piviul