Having the following line:
auth required pam_env.so
Documentation happily says
"This module is required—it must run successfully for authentication to proceed."
Great! What does really mean "run successfully". I know that it loads variables from
/etc/security/pam_env.conf that by the way in Centos and Ubuntu have all its lines commented out. Please could you explain me what does that really mean?
How can this module could run unsuccessfully? Or merely loads variable, what has this have to do with authentication?
I've read the pam.conf manpage:
required failure of such a PAM will ultimately lead to the PAM-API returning failure but only after the remaining stacked modules (for this service and type) have been invoked.
Perhaps, I missing something, but it says me nothing about this topic.
All in all, why the type is auth, and not session?