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k5login(5) [linux man page]

.K5LOGIN(5)                                                     File Formats Manual                                                    .K5LOGIN(5)

NAME
.k5login - Kerberos V5 acl file for host access. DESCRIPTION
The .k5login file, which resides in a user's home directory, contains a list of the Kerberos principals. Anyone with valid tickets for a principal in the file is allowed host access with the UID of the user in whose home directory the file resides. One common use is to place a .k5login file in root's home directory, thereby granting system administrators remote root access to the host via Kerberos. EXAMPLES
Suppose the user "alice" had a .k5login file in her home directory containing the following line: bob@FUBAR.ORG This would allow "bob" to use any of the Kerberos network applications, such as telnet(1), rlogin(1), rsh(1), and rcp(1), to access alice's account, using bob's Kerberos tickets. Let us further suppose that "alice" is a system administrator. Alice and the other system administrators would have their principals in root's .k5login file on each host: alice@BLEEP.COM joeadmin/root@BLEEP.COM This would allow either system administrator to log in to these hosts using their Kerberos tickets instead of having to type the root pass- word. Note that because "bob" retains the Kerberos tickets for his own principal, "bob@FUBAR.ORG", he would not have any of the privileges that require alice's tickets, such as root access to any of the site's hosts, or the ability to change alice's password. SEE ALSO
telnet(1), rlogin(1), rsh(1), rcp(1), ksu(1), telnetd(8), klogind(8) .K5LOGIN(5)

Check Out this Related Man Page

KERBEROS(1)						      General Commands Manual						       KERBEROS(1)

NAME
kerberos - introduction to the Kerberos system DESCRIPTION
The Kerberos system authenticates individual users in a network environment. After authenticating yourself to Kerberos, you can use net- work utilities such as rlogin, rcp, and rsh without having to present passwords to remote hosts and without having to bother with .rhosts files. Note that these utilities will work without passwords only if the remote machines you deal with support the Kerberos system. If you enter your username and kinit responds with this message: Principal unknown (kerberos) you haven't been registered as a Kerberos user. See your system administrator. A Kerberos name usually contains three parts. The first is the primary, which is usually a user's or service's name. The second is the instance, which in the case of a user is usually null. Some users may have privileged instances, however, such as ``root'' or ``admin''. In the case of a service, the instance is the fully qualified name of the machine on which it runs; i.e. there can be an rlogin service running on the machine ABC, which is different from the rlogin service running on the machine XYZ. The third part of a Kerberos name is the realm. The realm corresponds to the Kerberos service providing authentication for the principal. When writing a Kerberos name, the principal name is separated from the instance (if not null) by a slash, and the realm (if not the local realm) follows, preceded by an ``@'' sign. The following are examples of valid Kerberos names: david jennifer/admin joeuser@BLEEP.COM cbrown/root@FUBAR.ORG When you authenticate yourself with Kerberos you get an initial Kerberos ticket. (A Kerberos ticket is an encrypted protocol message that provides authentication.) Kerberos uses this ticket for network utilities such as rlogin and rcp. The ticket transactions are done trans- parently, so you don't have to worry about their management. Note, however, that tickets expire. Privileged tickets, such as those with the instance ``root'', expire in a few minutes, while tickets that carry more ordinary privileges may be good for several hours or a day, depending on the installation's policy. If your login session extends beyond the time limit, you will have to re-authenticate yourself to Kerberos to get new tickets. Use the kinit command to re- authenticate yourself. If you use the kinit command to get your tickets, make sure you use the kdestroy command to destroy your tickets before you end your login session. You should put the kdestroy command in your .logout file so that your tickets will be destroyed automatically when you logout. For more information about the kinit and kdestroy commands, see the kinit(1) and kdestroy(1) manual pages. Kerberos tickets can be forwarded. In order to forward tickets, you must request forwardable tickets when you kinit. Once you have for- wardable tickets, most Kerberos programs have a command line option to forward them to the remote host. Currently, Kerberos support is available for the following network services: rlogin, rsh, rcp, telnet, ftp, krdist (a Kerberized version of rdist), ksu (a Kerberized version of su), login, and Xdm. SEE ALSO
kdestroy(1), kinit(1), klist(1), kpasswd(1), rsh(1), rcp(1), rlogin(1), telnet(1), ftp(1), krdist(1), ksu(1), sclient(1), xdm(1), des_crypt(3), hash(3), krb5strings(3), krb5.conf(5), kdc.conf(5), kadmin(8), kadmind(8), kdb5_util(8), telnetd(8), ftpd(8), rdistd(8), sserver(8), klogind(8c), kshd(8c), login(8c) BUGS
AUTHORS
Steve Miller, MIT Project Athena/Digital Equipment Corporation Clifford Neuman, MIT Project Athena HISTORY
Kerberos was developed at MIT. OpenVision rewrote and donated the administration server, which is used in the current version of Kerberos 5. RESTRICTIONS
Copyright 1985,1986,1989-1996 Massachusetts Institute of Technology KERBEROS(1)
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