home *** CD-ROM | disk | FTP | other *** search
- Xref: sparky comp.sys.sun.admin:6209 comp.unix.admin:4948
- Newsgroups: comp.sys.sun.admin,comp.unix.admin
- Path: sparky!uunet!munnari.oz.au!manuel!durras!ivan
- From: ivan@durras.anu.edu.au (Ivan Dean)
- Subject: Re: NIS, slave servers and DNS access (actually disabling accounts)
- Message-ID: <ivan.715993948@durras>
- Sender: news@newshost.anu.edu.au
- Organization: Computer Services Centre, Australian National University
- References: <92241.144541QQ11@LIVERPOOL.AC.UK> <1992Aug28.163833.28635@fwi.uva.nl> <1992Sep1.001928.17876@zia.aoc.nrao.edu> <21452@rpp386.lonestar.org>
- Date: 8 Sep 92 23:12:28 GMT
- Lines: 48
-
- This thread has moved off into the area of disabling accounts, which is
- something I have had a bit of experience in. Recently we acquired sixty
- Xterminals for our teaching laboratories, and they change things quite
- noticeably.
-
- To recap, we've seen the following suggestions for disabling accounts :
-
- 1. Alter the password field of the user
- 2. Alter the shell of the user
-
- Suggestion 1. doesn't work if the user has a .rhosts file, or the
- /etc/hosts.equiv file allows them to log on directly, i.e. if a
- "trust relationship" is set up from another working account, because the
- user doesn't have to enter a password at all.
-
- Also, if you change a user's password, then you can't give them a message
- about why their account is unavailable when they log in. This is often
- desirable, and can only be achieved by altering a user's shell to a
- program which prints out the required message. Which leads us to
- suggestion 2, which is a good suggestion for logins that require shells.
-
- However, running an Xterminal with xdm, or a workstation with xdm, means that
-
- THEY DON'T NEED A WORKING SHELL TO USE THE SYSTEM !
-
- A user with their shell set to "/bin/false" can use the system via windowing
- tools such as textedit, mailtool, filemgr etc. quite happily. They can't
- start a cmdtool, shelltool or xterm for instance, but who cares ? I HAVE
- tried this on one of our Xterminals, and it DOES work. To get around the
- problem, you need to modify the standard startup sequence for xdm - we did
- it by running a program called xlogin (see archie for details). xlogin
- was modified to provide a mechanism for noting that an account was
- disabled, and printing out an appropriate message. Running a "standard"
- xdm setup does not provide this functionality, and as far as I'm aware,
- doesn't provide you with any way to disable a user other than altering
- their password, which of course, doesn't work in certain cases anyway.
-
- In summary, altering a user's password AND shell will disable that account,
- but the user has no idea what's wrong with their account. Changing one but
- not the other is generally not sufficient.
-
- Disclaimer : I don't know anything about SVR4 yet, so I'm writing about
- Suns running SunOS 4.1.x, and the X11R5 version of xdm.
- --
-
- -------------------------------------------------------------------
- Ivan Dean Here : x3261
- Faculties Computer Unit There : (06) 249 3261
-