Skip site navigation (1)Skip section navigation (2)

FreeBSD Man Pages

Man Page or Keyword Search:
Man Architecture
Apropos Keyword Search (all sections) Output format
home | help
KERBEROS(1)             FreeBSD General Commands Manual            KERBEROS(1)

       kerberos - introduction to the Kerberos system

       The Kerberos system authenticates individual users in a network
       environment.  After authenticating yourself to Kerberos, you can use
       network 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.
       All Athena timesharing machines and public workstations support

       Before you can use Kerberos, you must register as an Athena user, and
       you must make sure you have been added to the Kerberos database.  You
       can use the kinit command to find out.  This command tries to log you
       into the Kerberos system.  kinit will prompt you for a username and
       password.  Enter your username and password.  If the utility lets you
       login without giving you a message, you have already been registered.

       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

       A Kerberos name contains three parts.  The first is the principal name,
       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 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.  For example, at MIT there is a Kerberos running at the
       Laboratory for Computer Science and one running at Project Athena.

       When writing a Kerberos name, the principal name is separated from the
       instance (if not null) by a period, and the realm (if not the local
       realm) follows, preceded by an ``@'' sign.  The following are examples
       of valid Kerberos names:


       When you authenticate yourself with Kerberos, through either the
       workstation toehold system or the kinit command, Kerberos gives you 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 transparently, so you don't have to worry about their management.

       Note, however, that tickets expire.  Privileged tickets, such as root
       instance tickets, 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

       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 probably 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.

       Currently, Kerberos supports the following network services: rlogin,
       rsh, rcp, pop, ftp, telnet, AFS and NFS.

       kdestroy(1), kinit(1), klist(1), kpasswd(1), des_crypt(3), kerberos(3),

       Kerberos will not do authentication forwarding.  In other words, if you
       use rlogin to login to a remote host, you cannot use Kerberos services
       from that host until you authenticate yourself explicitly on that host.
       Although you may need to authenticate yourself on the remote host, be
       aware that when you do so, rlogin sends your password across the
       network in clear text.

       Steve Miller, MIT Project Athena/Digital Equipment Corporation
       Clifford Neuman, MIT Project Athena

       The following people helped out on various aspects of the system:

       Jeff Schiller designed and wrote the administration server and its user
       interface, kadmin.  He also wrote the dbm version of the database
       management system.

       Mark Colan developed the Kerberos versions of rlogin, rsh, and rcp, as
       well as contributing work on the servers.

       John Ostlund developed the Kerberos versions of passwd and userreg.

       Stan Zanarotti pioneered Kerberos in a foreign realm (LCS), and made
       many contributions based on that experience.

       Many people contributed code and/or useful ideas, including Jim Aspnes,
       Bob Baldwin, John Barba, Richard Basch, Jim Bloom, Bill Bryant, Rob
       French, Dan Geer, David Jedlinsky, John Kohl, John Kubiatowicz, Bob
       McKie, Brian Murphy, Ken Raeburn, Chris Reed, Jon Rochlis, Mike
       Shanzer, Bill Sommerfeld, Jennifer Steiner, Ted Ts'o, and Win Treese.

       COPYRIGHT 1985,1986 Massachusetts Institute of Technology

MIT Project Athena           Kerberos Version 4.0                  KERBEROS(1)


Want to link to this manual page? Use this URL:

home | help