The Kerberos Network Authentication Service (V5)
RFC 4120
| Document | Type |
RFC - Proposed Standard
(July 2005; Errata)
Obsoletes RFC 1510
|
|
|---|---|---|---|
| Last updated | 2015-06-26 | ||
| Stream | IETF | ||
| Formats | plain text pdf html bibtex | ||
| Stream | WG state | (None) | |
| Document shepherd | No shepherd assigned | ||
| IESG | IESG state | RFC 4120 (Proposed Standard) | |
| Consensus Boilerplate | Unknown | ||
| Telechat date | |||
| Responsible AD | Russ Housley | ||
| Send notices to | <jhutz+@cmu.edu> | ||
Network Working Group C. Neuman
Request for Comments: 4120 USC-ISI
Obsoletes: 1510 T. Yu
Category: Standards Track S. Hartman
K. Raeburn
MIT
July 2005
The Kerberos Network Authentication Service (V5)
Status of This Memo
This document specifies an Internet standards track protocol for the
Internet community, and requests discussion and suggestions for
improvements. Please refer to the current edition of the Internet
Official Protocol Standards" (STD 1) for the standardization state
and status of this protocol. Distribution of this memo is unlimited.
Copyright Notice
Copyright (C) The Internet Society (2005).
Abstract
This document provides an overview and specification of Version 5 of
the Kerberos protocol, and it obsoletes RFC 1510 to clarify aspects
of the protocol and its intended use that require more detailed or
clearer explanation than was provided in RFC 1510. This document is
intended to provide a detailed description of the protocol, suitable
for implementation, together with descriptions of the appropriate use
of protocol messages and fields within those messages.
Neuman, et al. Standards Track [Page 1]
RFC 4120 Kerberos V5 July 2005
Table of Contents
1. Introduction ....................................................5
1.1. The Kerberos Protocol ......................................6
1.2. Cross-Realm Operation ......................................8
1.3. Choosing a Principal with Which to Communicate .............9
1.4. Authorization .............................................10
1.5. Extending Kerberos without Breaking Interoperability ......11
1.5.1. Compatibility with RFC 1510 ........................11
1.5.2. Sending Extensible Messages ........................12
1.6. Environmental Assumptions .................................12
1.7. Glossary of Terms .........................................13
2. Ticket Flag Uses and Requests ..................................16
2.1. Initial, Pre-authenticated, and
Hardware-Authenticated Tickets ............................17
2.2. Invalid Tickets ...........................................17
2.3. Renewable Tickets .........................................17
2.4. Postdated Tickets .........................................18
2.5. Proxiable and Proxy Tickets ...............................19
2.6. Forwardable Tickets .......................................19
2.7. Transited Policy Checking .................................20
2.8. OK as Delegate ............................................21
2.9. Other KDC Options .........................................21
2.9.1. Renewable-OK .......................................21
2.9.2. ENC-TKT-IN-SKEY ....................................22
2.9.3. Passwordless Hardware Authentication ...............22
3. Message Exchanges ..............................................22
3.1. The Authentication Service Exchange .......................22
3.1.1. Generation of KRB_AS_REQ Message ...................24
3.1.2. Receipt of KRB_AS_REQ Message ......................24
3.1.3. Generation of KRB_AS_REP Message ...................24
3.1.4. Generation of KRB_ERROR Message ....................27
3.1.5. Receipt of KRB_AS_REP Message ......................27
3.1.6. Receipt of KRB_ERROR Message .......................28
3.2. The Client/Server Authentication Exchange .................29
3.2.1. The KRB_AP_REQ Message .............................29
3.2.2. Generation of a KRB_AP_REQ Message .................29
3.2.3. Receipt of KRB_AP_REQ Message ......................30
3.2.4. Generation of a KRB_AP_REP Message .................33
3.2.5. Receipt of KRB_AP_REP Message ......................33
3.2.6. Using the Encryption Key ...........................33
3.3. The Ticket-Granting Service (TGS) Exchange ................34
3.3.1. Generation of KRB_TGS_REQ Message ..................35
3.3.2. Receipt of KRB_TGS_REQ Message .....................37
3.3.3. Generation of KRB_TGS_REP Message ..................38
3.3.4. Receipt of KRB_TGS_REP Message .....................42
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