Features/KRB5DirCache

Feature Name

KRB5 DIR: Credential Caches

Summary

Kerberos 1.10 added a new cache storage type, DIR: which allows Kerberos to maintain TGTs for multiple KDCs simultaneously and auto-select between them when negotiating with Kerberized resources. Fedora should switch to using the DIR: cache format over the older FILE: cache format to support accessing mulitple Kerberos realms.

Owner

• Name: Stephen Gallagher

• Email: sgallagh@redhat.com

Current status

• Targeted release: Fedora 18
• Last updated: Sgallagh 17:00, 1 May 2012 (UTC)
• Percentage of completion: 25%

Detailed Description

Support of multiple Kerberos realms is a critical feature and has been one of the most-requested enhancements of Kerberos. Having the ability to acquire a single-sign-on credential for other realms without traditional hurdles will allow users to set up environments such as: 1) Log on to their local machine using their corporate Kerberos environment, acquiring that TGT 2) Present credentials and acquire a ticket for their partner's environment and be able to access resources in both without additional steps.

Benefit to Fedora

The basics are described in the Detailed Description section. Other potential benefits would be that it would make it simpler to eventually migrate the Fedora development infrastructure to use Kerberos. One of the major hurdles to this effort has always been that it would be difficult for users who already sign in to Kerberos environments to also work in Fedora. With this capability added, that's one fewer roadblock to this conversion.

Scope

Multiple packages will need to be updated to support this, though the changes to those packages in many cases will be limited. The necessary functionality is already available in the kerberos libraries provided by the 'krb5' package.

• krb5: Will need to change the default configuration to specify DIR: caches instead of FILE: caches
• SSSD: Will need to add support for the DIR: caches internally. See https://fedorahosted.org/sssd/ticket/974

Dependencies

• Features/KRB5CacheMove - This is not a strict dependency, but they are closely interconnected.

Documentation

• http://k5wiki.kerberos.org/wiki/Projects/Client_principal_selection

Comments and Discussion

• See Talk:Features/KRB5DirCache