Single Sign-On and the Corporate Directory, Part IV

We wrap up the single sign-on series with CUPS printing, SSH and firewall rules.
Extending Kerberos Use

Up until now, we've been dealing with extending the use of LDAP, but there are more ways we can make use of Kerberos as well. One important piece in your organization for which you might want single sign-on enabled is authenticating for Web resources. Many modern browsers, such as IE 6.0, Mozilla, Firefox and Safari, already (or can be made to) support GSSAPI negotiation. To make use of this, you can install and enable the Apache mod_auth_kerb module. It can negotiate ticket-based authentication for single sign-on or present the user with a traditional user name/password box and authenticate the user to the KDC.

One other extension of Kerberos has come in the form of NFSv4. Version 4 of NFS has included stronger security as part of the protocol. It has ACL support and can use a user's Kerberos credentials for access and rights. The CITI group at the University of Michigan is spearheading the Linux implementation of NFSv4 and has links to all the patches you'll need for the user-space tools. Recent 2.6 kernels come with support for NFSv4 and rpcsec_gss, but some distributions don't enable the support by default. The necessary packages can be emerged on Gentoo systems, and the support is fully there in Red Hat Enterprise Linux 4.

Wrapping Up

We've come a long way in this series of articles. You should have a scalable directory and single sign-on environment. We've gone over how to integrate heterogeneous clients into the infrastructure. Lastly, we've covered how you, the sysadmin, can more easily manage and leverage your LDAP and Kerberos environments.


This work was supported by the Mathematical, Information, and Computational Sciences Division subprogram of the Office of Advanced Scientific Computing Research, Office of Science, U.S. Department of Energy, under Contract W-31-109-ENG-38.4:08. Thanks to Justin Binns for the script.

Resources for this article: /article/8749.

Ti Leggett ( is a systems administrator for the Futures Laboratory of the Mathematics and Computer Science Division at Argonne National Laboratory. He also has a joint appointment with the Computation Institute at the University of Chicago.



Comment viewing options

Select your preferred way to display the comments and click "Save settings" to activate your changes.

A new distro??

anm's picture

Hi Ti,
How about creating a linux distro based on all the good things discussed here. Just download a distro, make few GUI driven configurations, and all set to have SSO in the organization?