[comp.unix.ultrix] Restricting logins to uucp on a specific line

mms@bnlux0.bnl.gov (Morris Strongson) (06/15/89)

    We are presently running Ultrix 2.0 on a Vax 11/780, and expect to go to 
3.0 shortly.  The need to restrict one incoming tty line to uucp logins only
has arisen, and we do not know how to to that.  Any information you can give
me as to how to impose such restrictions will be appreciated.  Thanks in
advance.
		Morris Strongson  INTERNET:  mms@bnlux0.bnl.gov
				  BITNET:    mms@bnlux0.BITNET
				  UUCP:      ...philabs!sbcs!bnlux0!mms
				       or    bnlux0!mms@uunet.uu.net

-- 
		Morris Strongson  INTERNET:  mms@bnlux0.bnl.gov
				  BITNET:    mms@bnlux0.BITNET
				  UUCP:      ...philabs!sbcs!bnlux0!mms
				       or    bnlux0!mms@uunet.uu.net

dold@mitisft.Convergent.COM (Clarence Dold) (06/15/89)

in article <1214@bnlux0.bnl.gov>, mms@bnlux0.bnl.gov (Morris Strongson) says:


>     We are presently running Ultrix 2.0 on a Vax 11/780, and expect to go to 
> 3.0 shortly.  The need to restrict one incoming tty line to uucp logins only
> has arisen, and we do not know how to to that.  Any information you can give

Three steps:
1) See if your version of login supports dialup passwords:
#strings /bin/login |grep d_pas
/etc/d_passwd

2) Create a /etc/dialups file containing the name of the tty you want to guard:
#-r--------   1 root  root   189 Nov 24 08:46 /etc/dialups

/dev/tty500
# /etc/dialups will contain all of the devices that
# **might** present Dialup Password, depending on 
# entries in /etc/d_passwd.

3) Create a /etc/d_passwd controlling all possible login shells:
#-r--------   1 root  root   368 Nov 24 08:45 /etc/d_passwd

# /etc/d_passwd contains all 'initial programs' allowed 
# when invoked on a line specified in /etc/dialups
# /bin/sh:13characterEncryption:
# The encrypted password is drawn over via grep after applying
# /bin/passwd to a superfluous entry in /etc/passwd.

/bin/sh:JUNK:
/bin/ksh:JUNK:
/bin/rsh:JUNK:

# A line to allow uucp entry with no password:
/usr/lib/uucp/uucico::

# Use links to different shell names to cause certain login ids 
# to require Dialup password, while other logins using the same
# shell with a different name don't need a password.

-- 
---
Clarence A Dold - dold@tsmiti.Convergent.COM		(408) 434-5293
		...pyramid!ctnews!tsmiti!dold
		P.O.Box 6685, San Jose, CA 95150-6685	MS#10-007

rbk@cbnewsk.ATT.COM (R. Brad Kummer) (06/24/89)

In article <1214@bnlux0.bnl.gov> mms@bnlux0.UUCP (Morris Strongson) writes:
>
>    We are presently running Ultrix 2.0 on a Vax 11/780, and expect to go to 
>3.0 shortly.  The need to restrict one incoming tty line to uucp logins only
>has arisen, and we do not know how to to that...

I don't know about Ultrix, but in SYSV you could set up a dial-up password
for the tty port.  This simply requires creating an /etc/dialups file which
contains the name(s) of tty ports declared to be "dialups," e.g.:

$ cat /etc/dialups
/dev/tty01

Next, you need to create an /etc/d_passwd file for the passwords.  The first
field of each line corresponds to the program run by login (determined from
the last field in /etc/passwd), i.e., uucico for a UUCP login and typically
/bin/sh (or NULL, which defaults to /bin/sh) for a "normal" login.  The
second field is the encrypted password, or NULL for no password.  Thus, the
following should accomplish what you want:

$ cat /etc/d_passwd
uucico::
:NP:

The first line creates no password for uucico, and the NP in the second
line effectively disables any other logins (a user trying to log in on
this port will be prompted with "Dialin password:" and any response will
produce a "Login incorrect" failure.

Incidentally, if you do want to create a valid dialin password for the line
(to allow "privileged" users to log in), you can use passwd to assign
the password to some user (perhaps temporarily) and then copy the
encrypted password from /etc/passwd.

Hope this helps.

	R. Brad Kummer	att!akguc!rbk
	AT&T Bell Laboratories,  Atlanta