From: utzoo!decvax!pur-ee!mahler
Newsgroups: net.general
Title: Users Exchanging Files
Article-I.D.: pur-ee.527
Posted: Thu Sep  9 09:12:41 1982
Received: Fri Sep 10 03:48:46 1982

The Engineering Computer Network (ECN) at Purdue has an approach
to allowing users to exchange files.  For those uniformed, ECN
supports a network of 8 780's  2 70's  3 45's and 3 DUAL 780's
in a teaching environment.  Some systems are large, running over
115 users with passwd files of > 2700 line.

Last spring, a alarming amount of SUID shells were found, most
users reported they were used to send files to their "friends."
The situation might have been solved with groups for a smaller
user population, but the adminstrative headaches for a system
of ECNs size were deemed huge.  Over the summer a 2 programs
were written to allow users to control "friendly" access to
their files.

I will post the manual pages to net.followup ... interested
parties may request copies via mail ... 

Steve Mahler, Network Services Manager, ECN Purdue
(decvax!pur-ee!mahler  ||  ucbvax!pur-ee!mahler)

ps - accordingly, chown is restricted on ECN machines ...sm