You already know that it's PAM-related, since it's a PAM config file. What extra info does the `pam_` give you? .so does give you some info (namely, that it's

You already know that it's PAM-related, since it's a PAM config file. What extra info does the `pam_` give you? .so does give you some info (namely, that it's an external shared object), but I'm not entirely certain how that alone gives you any better idea what's going on: that shared object could do literally anything. You need to know how PAM uses the shared object to know what's going on.