Relay-Version: version B 2.10 5/3/83; site utzoo.UUCP
Posting-Version: version B 2.10.2 9/18/84; site sfmag.UUCP
Path: utzoo!watmath!clyde!burl!ulysses!sfmag!mjs
From: mjs@sfmag.UUCP (M.J.Shannon)
Newsgroups: net.sources
Subject: Re: Lock your terminal for lunch
Message-ID: <679@sfmag.UUCP>
Date: Fri, 6-Sep-85 23:36:12 EDT
Article-I.D.: sfmag.679
Posted: Fri Sep  6 23:36:12 1985
Date-Received: Sat, 7-Sep-85 13:21:52 EDT
References: <131@pyuxv.UUCP>
Organization: AT&T Information Systems, Summit, NJ
Lines: 21

> #This is a great way to lock up your terminal without having to log off.
> 
> trap 'echo "PISS OFF"' 1 2 3 6 15
[ lots of shell program elided -mjs ]
> #from Rob Fair and George Bogatko

There are only 2 problems with this approach, one minor, the other fatal.
The minor one is that the password is kept in clear text.  This can probably
be dealt with effectively with appropriate permissions on the file (like
0700).  The fatal one is that since the shell is interpreting this file, a
bad-guy at the terminal can generate either interrupt or quit signals faster
than the shell can react (re-catch them).  Possibly using something like
	trap '' 1 2 3 6 15
may prevent the shell's need to react (but verify it before you use it!).
The real answer to the security problem is to never, NEVER, *NEVER* leave
your terminal unattended when you're logged in.
-- 
	Marty Shannon
UUCP:	ihnp4!attunix!mjs
Phone:	+1 (201) 522 6063
Disclaimer: I speak for no one.