[nylug-talk] Pam modules and usernames

[Stephen Tihor]

I have been doing some PAM work under older Unix systems and was just 
porting a modules to SLES9, when I observed that if the username a 
user enters does not appear in /etc/passwd (or the virtual 
/etc/passwd NSS generates) then the conversation function does not 
prompt for a password - but instead returns a fixed odd string (a 
couple of control characters and "INVALID").     I was able to 
duplicate this effect under telnet and ssh even with a simple module 
that just read in and logged the password entered, or at least tried 
to read one in :( .


(Now under normal circumstances my module will take username and 
password string, deetermine authentication and set PAM_USERNAME to a 
legal value before its done with the first (authentication) call but 
I am wondering if there is something going on in login.c or elsewhere 
that I am just plain missing?