CS/CE 218 Lecture -*-Outline-*- * Unix Security advert: basic to Unix is logging in and passwords. provides an essential function of an OS that serves several users ** authority where does the authority that you or I have come from? at ISU the department delegates authority (for this class) to me, I ask the system support group (the super users), to give you accounts *** superusers superusers can be found by sending mail to "ssg" or going to room 130 Atanasoff Q: What are some things a superuser does? Am I a superuser? why are superusers needed? *** accounts (logins) Q: Would accounts be necessary even if we didn't care about security? give each user his/her own environment fit to our culture. would accounts be useful even on a PC? ** security Q: What security protects your account? passwords, not echoed, ... note: name of your account is public (cf. the who command) Q: Would passwords be useful even if we didn't care about security? why are passwords required at ISU? passwords must contain at least 2 alphabetic, and 1 non-alphabetic char *** passwords discuss choosing a "good" password with... Q: If you were going to guess someone's password, what kinds of passwords would you guess? make a list on the board... what do you do if you forget your password? *** terminal sessions each terminal session is the responsibility of one account (you) how do you end a terminal session? Q: what happens if you don't log out before walking away from your terminal?