[comp.protocols.tcp-ip.ibmpc] The PC as a trusted client in a TCP/IP network

whna@cgch.UUCP (Heinz Naef) (11/21/89)

Hello system integrators,
what could be done to turn existing personal computers (industry standard)
into real trusted clients on a TCP/IP network? What activities would be
required at the organizational and at the technical level?
 - Would it be necessary to disable/remove the floppy disk unit?
 - Would it be a good idea to boot the PC over the network interface
   (learning IP-address, loading DOS, etc.)?
   Did anyone implement this already (e. g. using BootP, etc.)?
 - Would it be better to choose an application gateway solution, i. e.
   implementing some proxy-Telnet, -FTP, -NFS, -etc. agent on a departemental
   host which is accessed by corresponding PC clients?
 - etc.
Any comments, suggestions, pointers to solutions, etc. are appreciated. I will
summarize to the net, so you could e-mail instead of followup-posting to save
News bandwidth.
Thanks, and best regards,
Heinz Naef, c/o CIBA-GEIGY AG, R-1045.3.37, P.O.Box, CH-4002 Basel, Switzerland
  UUCP:     cgch!whna
  Internet: whna%cgch.uucp@uunet.uu.net              Phone: (+41) 61 697 26 75
  BITNET:   whna%cgch.uucp@cernvax.bitnet            Fax:   (+41) 61 697 32 88

romkey@amiga.UUCP (John Romkey) (11/21/89)

This isn't the answer you're looking for, but I think it's just a bad
idea to trust a PC in a networked environment.
			- john romkey
USENET/UUCP: romkey@asylum.sf.ca.us	Internet: romkey@ftp.com
"Some people walk on water/Some people walk on broken glass/Some people walk
 round and round in their dreams/Some just keep falling down." Laurie Anderson

werner@nikhefk.UUCP (Werner Vogels) (11/22/89)

In article <8911202309.AA06824@asylum.sf.ca.us> romkey@asylum.sf.ca.us writes:
>This isn't the answer you're looking for, but I think it's just a bad
>idea to trust a PC in a networked environment.
>			- john romkey
>.......

I think you should treat PC's in the same way you treat other workstations :

	             NEVER TRUST THEM !!!!!!
		     
they are a main security problem. On machine's were a user can control all the 
memory and the devices, one can never be sure about the identity of the user,
the processes and the machine itself.

A solution to these authentication and authorization problems is provided
by Project Athena's (M.I.T) kerberos.  We are currently trying to port the
programming and data encryption libaries to the PC envirionment, so it might
be possible in the near future to have PC's use services on other machines. 

When we have succeeded we will notified the netcommunity about the diff's.

Werner H.P. Vogels

Software Expertise Centrum                      
Haagse Hogeschool, Intersector Informatica      tel: +31 70 618419
Louis Couperusplein 2-19, 2514 HP Den Haag      E-mail: werner@nikhefk.nikhef.nl
The Netherlands                                      or werner@hhinsi.uucp

jon@athena.mit.edu (Jon A. Rochlis) (11/23/89)

In article <907@cgch.UUCP> whna@cgch.UUCP (Heinz Naef) writes:
>Hello system integrators,
>what could be done to turn existing personal computers (industry standard)
>into real trusted clients on a TCP/IP network? 

My 2 cents: Don't try to turn PC's into "trusted clients".  Don't
build around the concept of trusted clients at all.  Instead assume
all clients run with software (possibly even hardware) written from
the ground up by a cracker.  Assume all communications are monitored
by the "bad guy".  Require something like Kerberos to make the client
process prove its identity to a server.  Encrypt data streams or do
crypto-checksums depeneding upon the sensitivity of the data in
question.  Don't trust the software on the client.  After unless you
control and secure all the wire, somebody can pretty easily hook up
their own portable PC and at the very least run a sniffer to grab all
the packets as they go over the wire.

		-- Jon

cpcahil@virtech.uucp (Conor P. Cahill) (11/23/89)

> control and secure all the wire, somebody can pretty easily hook up
> their own portable PC and at the very least run a sniffer to grab all
> the packets as they go over the wire.

Speaking of sniffers,  can somebody send me information on what hardware 
is available for a portable pc to collect/view/analyze ethernet traffic
(and hopefully decript the TCP/IP packets) on both thin and thicknet.

Thanks in advance
-- 
+-----------------------------------------------------------------------+
| Conor P. Cahill     uunet!virtech!cpcahil      	703-430-9247	!
| Virtual Technologies Inc.,    P. O. Box 876,   Sterling, VA 22170     |
+-----------------------------------------------------------------------+

henry@utzoo.uucp (Henry Spencer) (11/25/89)

In article <907@cgch.UUCP> whna@cgch.UUCP (Heinz Naef) writes:
>what could be done to turn existing personal computers (industry standard)
>into real trusted clients on a TCP/IP network? ...

Rip out the boards.  Save the monitor, case, and power supply.  Put a
decent processor (with memory management) in, and run a decent operating
system (one that pays some attention to security).

Unless you construct an environment in which users cannot do any
programming at all -- difficult -- it can't be done with standard PCs.
-- 
That's not a joke, that's      |     Henry Spencer at U of Toronto Zoology
NASA.  -Nick Szabo             | uunet!attcan!utzoo!henry henry@zoo.toronto.edu

romkey@amiga.UUCP (John Romkey) (11/25/89)

But Henry, the problem is that your average single user workstation is
no more secure than a PC is; the user can usually become root pretty
easily and hack whatever he or she wants. A lot of the problem is security 
paridigms that depend on your machine to have its proper IP address or
the use of "secure" port numbers.

I guess you did say "a decent operating system (one that pays some
attention to security)", and I don't want to get into a discussion of
whether or not UNIX (and which release of whoever's version) is
decent. But basically, I believe that the problem isn't that MS-DOS is
awful (it is), but that the security paridigms in place are bogus.
			- john romkey
USENET/UUCP: romkey@asylum.sf.ca.us	Internet: romkey@ftp.com
"Some people walk on water/Some people walk on broken glass/Some people walk
 round and round in their dreams/Some just keep falling down." Laurie Anderson