2.4.3 rlogin

The Kerberos V5 rlogin command works exactly like the standard UNIX rlogin program, with the following Kerberos options added:

-f

forwards a copy of your tickets to the remote host.

-F

forwards a copy of your tickets to the remote host, and marks them re-forwardable from the remote host.

-k realm

requests tickets for the remote host in the specified realm, instead of determining the realm itself.

-x

encrypts the input and output data streams (the username is sent unencrypted)

For example, if david wanted to use the standard UNIX rlogin to connect to the machine daffodil.example.com, he would type:

     shell% rlogin daffodil.example.com -l david
     Password:  <- david types his password here
     Last login: Fri Jun 21 10:36:32 from :0.0
     Copyright (c) 1980, 1983, 1986, 1988, 1990, 1991, 1993, 1994
             The Regents of the University of California.   All rights reserved.
     
     NetBSD 1.1: Tue May 21 00:31:42 EDT 1996
     
     Welcome to NetBSD!
     shell%

Note that the machine daffodil.example.com asked for david's password. When he typed it, his password was sent over the network unencrypted. If an intruder were watching network traffic at the time, that intruder would know david's password.

If, on the other hand, jennifer wanted to use Kerberos V5 rlogin to connect to the machine trillium.mit.edu, she could forward a copy of her tickets, mark them as not forwardable from the remote host, and request an encrypted session as follows:

     shell% rlogin trillium.mit.edu -f -x
     This rlogin session is using DES encryption for all data transmissions.
     Last login: Thu Jun 20 16:20:50 from daffodil
     Athena Server (sun4) Version 9.1.11 Tue Jul 30 14:40:08 EDT 2002
     shell%

Note that jennifer's machine used Kerberos to authenticate her to trillium.mit.edu, and logged her in automatically as herself. She had an encrypted session, a copy of her tickets were waiting for her, and she never typed her password.

If you forwarded your Kerberos tickets, rlogin automatically destroys them when it exits. The full set of options to Kerberos V5 rlogin are discussed in the Reference section of this manual. (see rlogin Reference)