Re: server side PAM authentication

> Could the absence of session messages from pam_pwdb.so be due to pam.c not
> calling pam_open_session()/pam_close_session() after successful
> pam_authenticate()?

Yes, probably so. I've just taken a look at the sources of
pam_pwdb.c: its open_session handler calls _unix_open_session
which seems to be issuing the diagnostics.

Regards,
Sergey