A Generalized Framework for Kerberos Pre-Authentication
RFC 6113
Document | Type |
RFC - Proposed Standard
(April 2011; No errata)
Updates RFC 4120
|
|
---|---|---|---|
Authors | Sam Hartman , Larry Zhu | ||
Last updated | 2018-12-20 | ||
Stream | IETF | ||
Formats | plain text html pdf htmlized bibtex | ||
Stream | WG state | (None) | |
Document shepherd | No shepherd assigned | ||
IESG | IESG state | RFC 6113 (Proposed Standard) | |
Consensus Boilerplate | Unknown | ||
Telechat date | |||
Responsible AD | Tim Polk | ||
Send notices to | (None) |
Internet Engineering Task Force (IETF) S. Hartman Request for Comments: 6113 Painless Security Updates: 4120 L. Zhu Category: Standards Track Microsoft Corporation ISSN: 2070-1721 April 2011 A Generalized Framework for Kerberos Pre-Authentication Abstract Kerberos is a protocol for verifying the identity of principals (e.g., a workstation user or a network server) on an open network. The Kerberos protocol provides a facility called pre-authentication. Pre-authentication mechanisms can use this facility to extend the Kerberos protocol and prove the identity of a principal. This document describes a more formal model for this facility. The model describes what state in the Kerberos request a pre- authentication mechanism is likely to change. It also describes how multiple pre-authentication mechanisms used in the same request will interact. This document also provides common tools needed by multiple pre- authentication mechanisms. One of these tools is a secure channel between the client and the key distribution center with a reply key strengthening mechanism; this secure channel can be used to protect the authentication exchange and thus eliminate offline dictionary attacks. With these tools, it is relatively straightforward to chain multiple authentication mechanisms, utilize a different key management system, or support a new key agreement algorithm. 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/rfc6113. Hartman & Zhu Standards Track [Page 1] RFC 6113 Kerberos Preauth Framework April 2011 Copyright Notice Copyright (c) 2011 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. Hartman & Zhu Standards Track [Page 2] RFC 6113 Kerberos Preauth Framework April 2011 Table of Contents 1. Introduction ....................................................4 1.1. Conventions and Terminology Used in This Document ..........5 1.2. Conformance Requirements ...................................5 2. Model for Pre-Authentication ....................................6 2.1. Information Managed by the Pre-Authentication Model ........7 2.2. Initial Pre-Authentication Required Error ..................9 2.3. Client to KDC .............................................10 2.4. KDC to Client .............................................11 3. Pre-Authentication Facilities ..................................12 3.1. Client Authentication Facility ............................13 3.2. Strengthening Reply Key Facility ..........................13 3.3. Replace Reply Key Facility ................................14 3.4. KDC Authentication Facility ...............................15 4. Requirements for Pre-Authentication Mechanisms .................15 4.1. Protecting Requests/Responses .............................16 5. Tools for Use in Pre-Authentication Mechanisms .................17 5.1. Combining Keys ............................................17 5.2. Managing States for the KDC ...............................19 5.3. Pre-Authentication Set ....................................20 5.4. Definition of Kerberos FAST Padata ........................23 5.4.1. FAST Armors ........................................24 5.4.2. FAST Request .......................................26 5.4.3. FAST Response ......................................30 5.4.4. Authenticated Kerberos Error Messages UsingShow full document text