Problem Statement on the Cross-Realm Operation of Kerberos
RFC 5868
Document | Type | RFC - Informational (May 2010; No errata) | |
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Authors | Ken'ichi Kamada , Masahiro Ishiyama , Shoichi Sakane , Saber Zrelli | ||
Last updated | 2018-12-20 | ||
Stream | IETF | ||
Formats | plain text html pdf htmlized bibtex | ||
Reviews | |||
Stream | WG state | (None) | |
Document shepherd | No shepherd assigned | ||
IESG | IESG state | RFC 5868 (Informational) | |
Action Holders |
(None)
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Consensus Boilerplate | Unknown | ||
Telechat date | |||
Responsible AD | Tim Polk | ||
Send notices to | (None) |
Internet Engineering Task Force (IETF) S. Sakane Request for Comments: 5868 K. Kamada Category: Informational S. Zrelli ISSN: 2070-1721 Yokogawa Electric Corp. M. Ishiyama Toshiba Corp. May 2010 Problem Statement on the Cross-Realm Operation of Kerberos Abstract This document provides background information regarding large-scale Kerberos deployments in the industrial sector, with the aim of identifying issues in the current Kerberos cross-realm authentication model as defined in RFC 4120. This document describes some examples of actual large-scale industrial systems, and lists requirements and restrictions regarding authentication operations in such environments. It also identifies a number of requirements derived from the industrial automation field. Although they are found in the field of industrial automation, these requirements are general enough and are applicable to the problem of Kerberos cross-realm operations. Status of This Memo This document is not an Internet Standards Track specification; it is published for informational purposes. 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). Not all documents approved by the IESG are a candidate for any level of Internet Standard; see 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/rfc5868. Sakane, et al. Informational [Page 1] RFC 5868 Kerberos Cross-Realm Operation Problem Statement May 2010 Copyright Notice Copyright (c) 2010 IETF Trust and the persons identified as the document authors. All rights reserved. This document is subject to BCP 78 and the IETF Trust's Legal Provisions Relating to IETF Documents (http://trustee.ietf.org/license-info) in effect on the date of publication of this document. Please review these documents carefully, as they describe your rights and restrictions with respect to this document. Code Components extracted from this document must include Simplified BSD License text as described in Section 4.e of the Trust Legal Provisions and are provided without warranty as described in the Simplified BSD License. Table of Contents 1. Introduction ....................................................3 2. Kerberos System .................................................4 2.1. Kerberos Basic Operation ...................................4 2.2. Cross-Realm Operation ......................................4 3. Applying Cross-Realm Kerberos in Complex Environments ...........5 4. Requirements ....................................................7 5. Issues ..........................................................8 5.1. Unreliability of Authentication Chain ......................8 5.2. Possibility of MITM in the Indirect Trust Model ............8 5.3. Scalability of the Direct Trust Model ......................9 5.4. Exposure to DoS Attacks ....................................9 5.5. Client's Performance ......................................10 5.6. Kerberos Pre-Authentication Problem in Roaming Scenarios ..10 6. Implementation Considerations ..................................11 7. Security Considerations ........................................11 8. Acknowledgements ...............................................11 9. References .....................................................11 9.1. Normative References ......................................11 9.2. Informative References ....................................11 Sakane, et al. Informational [Page 2] RFC 5868 Kerberos Cross-Realm Operation Problem Statement May 2010 1. Introduction Kerberos Version 5 is a widely deployed mechanism that enables a server to authenticate a client before granting it access to a certain service. Each client belongs to a managed domain called a realm. Kerberos supports authentication when a client and a server belong to different realms. This is called cross-realm authentication. There exist several ways for using Kerberos in large-scale distributed systems. Such infrastructures are typically split into several managed domains for geographical reasons, and to implement different management policies. In order to ensure smooth networkShow full document text