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From: cdold@starfish.Convergent.COM (Clarence Dold)
Newsgroups: comp.unix.wizards
Subject: Re: Selectively disable login at specified line?
Summary: Maybe you can use Dialup Passwords
Keywords: login getty tty ultrix csh
Message-ID: <734@starfish.Convergent.COM>
Date: 29 Sep 88 23:23:14 GMT
References: <1227@tuhold>
Organization: Convergent Technologies, San Jose, CA
Lines: 55

In article <1227@tuhold>, gfl@tuhold (Gerhard Fleischanderl) writes:
> 
> We want to restrict login-access at a specified terminal line
> to a group of designated users, with the other ttys still
> accessible to all users.

Even though it isn't documented, UNIX SysV 2.2 contains a dialup password
feature, that can be invoked for certain lines, and selectively for 
certain login initial programs.
Try strings /bin/login|grep passwd
to see if your login is looking for d_passwd.  If it is:
/etc/dialups is a list of the ports you *might* want to block:

	# /etc/dialups will contain all of the devices that
	# **might** present Dialup Password, depending on 
	# entries in /etc/d_passwd.
	/dev/tty023
	/dev/tty024
	/dev/tty025
	/dev/tty026
	
	
/etc/d_passwd contains a description of the initial programs subject to
password if they are invoked from one of the 'dialup' lines:
	
	/bin/jsh:XfCQ/Cu1tfd9g:
	/bin/sh::
	/usr/bin/ksh::
	
	# /etc/d_passwd contains all 'initial programs' allowed 
	# when invoked on a line specified in /etc/dialups
	
	# A line to allow uucp entry with no password:
	/usr/lib/uucp/uucico::
	
	# /bin/sh:13characterEncryption:
	# The encrypted password is drawn over via grep after applying
	# /bin/passwd to a superfluous entry in /etc/passwd.
	
	# 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.
	# In this example, restricted users show /bin/jsh as their shell
	# While the other users specify /bin/sh, actually linked.

	#-r--------   1 root  root   368 Nov 24 08:45 /etc/d_passwd
	#-r--------   1 root  root   189 Nov 24 08:46 /etc/dialups
	#-r-xr-xr-x   3 bin   bin  45470 May 19 15:32 /bin/sh
	#-r-xr-xr-x   3 bin   bin  45470 May 19 15:32 /bin/jsh
	
-- 
---
Clarence A Dold - cdold@starfish.Convergent.COM		(408) 435-5274
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		P.O.Box 6685, San Jose, CA 95150-6685