Internet Engineering Task Force (IETF) S. Hartman, Ed.
Request for Comments: 6806 Painless Security
Updates: 4120 K. Raeburn
Category: Standards Track MIT
ISSN: 2070-1721 L. Zhu
Microsoft Corporation
November 2012
Kerberos Principal Name Canonicalization and Cross-Realm Referrals
Abstract
This memo documents a method for a Kerberos Key Distribution Center
(KDC) to respond to client requests for Kerberos tickets when the
client does not have detailed configuration information on the realms
of users or services. The KDC will handle requests for principals in
other realms by returning either a referral error or a cross-realm
Ticket-Granting Ticket (TGT) to another realm on the referral path.
The clients will use this referral information to reach the realm of
the target principal and then receive the ticket. This memo also
provides a mechanism for verifying that a request has not been
tampered with in transit. This memo updates RFC 4120.
Status of This Memo
This is an Internet Standards Track document.
This document is a product of the Internet Engineering Task Force
(IETF). It represents the consensus of the IETF community. It has
received public review and has been approved for publication by the
Internet Engineering Steering Group (IESG). Further information on
Internet Standards is available in Section 2 of RFC 5741.
Information about the current status of this document, any errata,
and how to provide feedback on it may be obtained at
http://www.rfc-editor.org/info/rfc6806.
Copyright Notice
Copyright (c) 2012 IETF Trust and the persons identified as the
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Hartman, et al. Standards Track [Page 1]RFC 6806 KDC Referrals November 2012
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Table of Contents
1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . . 3
2. Conventions Used in This Document . . . . . . . . . . . . . . 4
3. Requesting a Referral . . . . . . . . . . . . . . . . . . . . 4
4. Realm Organization Model . . . . . . . . . . . . . . . . . . . 5
4.1. Trust Assumptions . . . . . . . . . . . . . . . . . . . . 5
5. Enterprise Principal Name Type . . . . . . . . . . . . . . . . 6
6. Name Canonicalization . . . . . . . . . . . . . . . . . . . . 7
7. Client Referrals . . . . . . . . . . . . . . . . . . . . . . . 9
8. Server Referrals . . . . . . . . . . . . . . . . . . . . . . . 10
9. Cross-Realm Routing . . . . . . . . . . . . . . . . . . . . . 11
10. Caching Information . . . . . . . . . . . . . . . . . . . . . 11
11. Negotiation of FAST and Detecting Modified Requests . . . . . 12
12. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 13
13. Security Considerations . . . . . . . . . . . . . . . . . . . 13
13.1. Shared-Password Case . . . . . . . . . . . . . . . . . . . 16
13.2. Pre-Authentication Data . . . . . . . . . . . . . . . . . 16
14. Acknowledgments . . . . . . . . . . . . . . . . . . . . . . . 17
15. References . . . . . . . . . . . . . . . . . . . . . . . . . . 17
15.1. Normative References . . . . . . . . . . . . . . . . . . . 17
15.2. Informative References . . . . . . . . . . . . . . . . . . 17
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