August 2003
Intermediate to advanced
270 pages
10h 9m
English
Content preview from Kerberos: The Definitive GuideBecome an O’Reilly member and get unlimited access to this title plus top books and audiobooks from O’Reilly and nearly 200 top publishers, thousands of courses curated by job role, 150+ live events each month,
O’Reilly covers everything we've got, with content to help us build a world-class technology community, upgrade the capabilities and competencies of our teams, and improve overall team performance as well as their engagement.I wanted to learn C and C++, but it didn't click for me until I picked up an O'Reilly book. When I went on the O’Reilly platform, I was astonished to find all the books there, plus live events and sandboxes so you could play around with the technology.I’ve been on the O’Reilly platform for more than eight years. I use a couple of learning platforms, but I'm on O'Reilly more than anybody else. When you're there, you start learning. I'm never disappointed.I'm always learning. So when I got on to O'Reilly, I was like a kid in a candy store. There are playlists. There are answers. There's on-demand training. It's worth its weight in gold, in terms of what it allows me to do.
DNS Domain Name-to-Realm Mapping
Kerberos can also use DNS for domain name-to-realm mapping. This mapping, provided by the domain_realm stanza in MIT-style krb5.conf files, can also be provided through TXT records in DNS. The TXT record format for specifying domain name-to-realm mappings is similar to the SRV record format for locating Kerberos KDCs within a given Kerberos realm. It contains three major fields:
- Service
This field is always
_kerberos.- Domain/host name
This field is the DNS domain name or hostname.
- Realm name
This field is the Kerberos realm associated with the domain name in the previous field.
An example, mapping all hosts within the domain wedgie.org to the Kerberos realm WEDGIE.ORG is shown below:
_kerberos.wedgie.org. IN TXT "WEDGIE.ORG"
Note that the latest Kerberos Clarifications call for less dependence on the insecure DNS service to perform domain name-to-realm mapping for future implementations of Kerberos. This DNS-to-realm mapping is used by Windows’ Active Directory services to locate realm information, and was documented as part of an Internet Draft. However, the most recent Kerberos Clarifications drafts obsoletes the older Internet Draft and strongly recommends against using unsecured DNS services to provide this mapping.
Become an O’Reilly member and get unlimited access to this title plus top books and audiobooks from O’Reilly and nearly 200 top publishers, thousands of courses curated by job role, 150+ live events each month,
and much more.
Read now
Unlock full access
More than 5,000 organizations count on O’Reilly
O’Reilly covers everything we've got, with content to help us build a world-class technology community, upgrade the capabilities and competencies of our teams, and improve overall team performance as well as their engagement.Julian F.
I wanted to learn C and C++, but it didn't click for me until I picked up an O'Reilly book. When I went on the O’Reilly platform, I was astonished to find all the books there, plus live events and sandboxes so you could play around with the technology.Addison B.
I’ve been on the O’Reilly platform for more than eight years. I use a couple of learning platforms, but I'm on O'Reilly more than anybody else. When you're there, you start learning. I'm never disappointed.Amir M.
I'm always learning. So when I got on to O'Reilly, I was like a kid in a candy store. There are playlists. There are answers. There's on-demand training. It's worth its weight in gold, in terms of what it allows me to do.