Relay-Version: version B 2.10 5/3/83; site utzoo.UUCP
Posting-Version: version B 2.10.1 6/24/83; site iitcs.UUCP
Path: utzoo!watmath!clyde!burl!ulysses!mhuxr!mhuxt!houxm!ihnp4!iitcs!draughn
From: draughn@iitcs.UUCP (Mark Draughn)
Newsgroups: net.unix-wizards
Subject: Re: Another reason why a few sources should come with binary licenses
Message-ID: <164@iitcs.UUCP>
Date: Tue, 3-Sep-85 22:06:46 EDT
Article-I.D.: iitcs.164
Posted: Tue Sep  3 22:06:46 1985
Date-Received: Thu, 5-Sep-85 09:07:23 EDT
References: <1149@brl-tgr.ARPA>
Reply-To: draughn@iitcs.UUCP (Mark draughn)
Organization: Illinois Institute of Technology, Chicago Il.
Lines: 29
Summary: 

In article <1149@brl-tgr.ARPA> root%bostonu.csnet@csnet-relay.arpa (BostonU SysMgr) writes:
 [...]
>Here's another one that was just brought up on the SECURITY mailing list.
>If user's are not careful about password creation (and people are just
>people) then a reasonably determined cracker can grab the encrypted string
>in /etc/passwd and run it against dictionaries (this is all well documented
>in "The Security of UNIX", I think that was Kernighan, sorry, working from
>memory here.)
>
>A trivial defense (used I believe years ago at Harvard and probably lots
>of other source sites) was to make /etc/passwd a dummy file (so most
>software is undisturbed) which does not contain encrypted strings but
>otherwise is publicly readable. You then create another, unreadable,
>copy (call it /etc/passwd.nr) with the strings. The only two programs
>that I can think of that use those encrypted strings (as delivered) are
>login.c and passwd.c, just modify those to use the unreadable version (easy.)
>It would also be handy to have a script that can be run that builds the
>readable from the unreadable when it is modified (easy.) 
[...]
In my UNIX manual it is pointed out several times that it is a crock
that user information (office, name, shell, etc.) is stored in the
password file.  It should be in a separate database.  So far, it
isn't.  I guess it would be easier to move the passwords than it
would be to move anything else.  This should be a standard part
of UNIX.

(Not that I don't think that a few source files would be nice.  I am at
a university so we have source,  but we also run VMS without source
and I wish I had it.)