[comp.unix.questions] /etc/passwd consolidation

hamilton@harrison.cs.unc.edu (Johnny Hamilton) (03/04/89)

 
        title:  password distribution mechanism sought


        QUESTION:
        I would like to locate a utility that would allow users to
        change their password on one machine (in this case a VAX 6310
        running ULTRIX), and have that change automatically propagated
        to all the other department machines on which they have accounts.
        This does not necessarily mean that the user will have an active
        account on the "password server", but will have an entry in
        /etc/passwd for propagation/consistency.

        Optimally, this utility would distribute the encoded password
        so that our programs that search for easy-to-break passwords would
        only have to work on one encryption for each user.

        Our department has a large number and variety of UNIX machines,
        including suns, VAXes, and a Data General.  All but the DG run some
        version of BSD UNIX (ULTRIX, 4.3 Mt. Xinu, SUN/OS), and the DG runs
        DG/UX, a System V/4.2 combination.  The suns have a common user com-
        munity, but each of the other machines has a separate set of users
        and therefore a separate password file.

        While we have the ability to use the yellow pages, the different
        users on each machine make this undesirable.

        I would like to hear from anyone who has installed such a system.

        Thanks in advance.

        Johnny D. Hamilton
        Research Assistant
        University North Carolina at Chapel Hill
        hamilton@cs.unc.edu

Makey@LOGICON.ARPA (Jeff Makey) (03/04/89)

In article <7078@thorin.cs.unc.edu> hamilton@harrison.cs.unc.edu (Johnny Hamilton) writes:
>        Optimally, this utility would distribute the encoded password
>        so that our programs that search for easy-to-break passwords would
>        only have to work on one encryption for each user.

Of course, this also means that *their* (the bad guys') programs that
search for easy-to-guess (and not-so-easy-to-guess) passwords would
only have to work on one encryption for each user.  Actually, the only
place you would have to run your guesser is at the password server
node, since you would know that any password guessed there would be on
all the other machines as well.  The bad guys would know this too,
naturally.

I hope you have taken into consideration the security risks of using
the same password on more than one machine, since this must be weighed
against the convenience of this scheme.

                           :: Jeff Makey

Department of Tautological Pleonasms and Superfluous Redundancies Department
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rbj@dsys.icst.nbs.gov (Root Boy Jim) (04/04/89)

? From: Jeff Makey <Makey@logicon.arpa>

? I hope you have taken into consideration the security risks of using
? the same password on more than one machine, since this must be weighed
? against the convenience of this scheme.

?                            :: Jeff Makey

? Department of Tautological Pleonasms and Superfluous Redundancies Department
?     Disclaimer: Logicon doesn't even know we're running news.
?     Internet: Makey@LOGICON.ARPA    UUCP: {nosc,ucsd}!logicon.arpa!Makey

I must regrettably disagree with my former colleague on the security
risks. It depends on what assumptions you make. If your users use .rhosts,
then one password is actually safer. Multiple passwords give the bad guys
multiple targets, any of which would allow access to all machines.

To answer the guys original question, you can run Yellow Pages if you
have Suns, or people who are tracking Sun's NFS/RPC/XDR networking
software, such as Sequent. However, YP is fraught with it's own problems,
such as not working well with nameservers.

Don Libes <libes@cme.nbs.gov> just posted a network wide password checker
to (whatever they call) net.sources (these days) which might also help.

	Catman Rshd <rbj@nav.icst.nbs.gov>
	Author of "The Daemonic Versions"

jim@cs.strath.ac.uk (Jim Reid) (04/05/89)

In article <18929@adm.BRL.MIL> rbj@dsys.icst.nbs.gov (Root Boy Jim) writes:
>.......................... However, YP is fraught with it's own problems,
>such as not working well with nameservers.

This is an understatement to say the least. YP is riddled with so many
security holes, you might as well leave /etc/passwd world writable.
Worrying about users having the same password on all the hosts on your
network pales into insignificance when compared to the troubles that
Yellow Pages can cause.

		Jim
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Makey@LOGICON.ARPA (Jeff Makey) (04/13/89)

In article <18929@adm.BRL.MIL> rbj@dsys.icst.nbs.gov (Root Boy Jim) writes:
>? From: Jeff Makey <Makey@logicon.arpa>
>?
>? I hope you have taken into consideration the security risks of using
>? the same password on more than one machine, since this must be weighed
>? against the convenience of this scheme.
>
>If your users use .rhosts,
>then one password is actually safer. Multiple passwords give the bad guys
>multiple targets, any of which would allow access to all machines.

Agreed.  If you are willing to let a breach of security on one machine
lead trivially to breaches of other machines, then by all means stick
to a single difficult-to-guess password and .rhosts files.

                           :: Jeff Makey

Department of Tautological Pleonasms and Superfluous Redundancies Department
    Disclaimer: Logicon doesn't even know we're running news.
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