RFC 2402 (rfc2402) - Page 1 of 22
IP Authentication Header
Alternative Format: Original Text Document
Network Working Group S. Kent
Request for Comments: 2402 BBN Corp
Obsoletes: 1826 R. Atkinson
Category: Standards Track @Home Network
November 1998
IP Authentication Header
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 (1998). All Rights Reserved.
Table of Contents
1. Introduction......................................................2
2. Authentication Header Format......................................3
2.1 Next Header...................................................4
2.2 Payload Length................................................4
2.3 Reserved......................................................4
2.4 Security Parameters Index (SPI)...............................4
2.5 Sequence Number...............................................5
2.6 Authentication Data ..........................................5
3. Authentication Header Processing..................................5
3.1 Authentication Header Location...............................5
3.2 Authentication Algorithms....................................7
3.3 Outbound Packet Processing...................................8
3.3.1 Security Association Lookup.............................8
3.3.2 Sequence Number Generation..............................8
3.3.3 Integrity Check Value Calculation.......................9
3.3.3.1 Handling Mutable Fields............................9
3.3.3.1.1 ICV Computation for IPv4.....................10
3.3.3.1.1.1 Base Header Fields.......................10
3.3.3.1.1.2 Options..................................11
3.3.3.1.2 ICV Computation for IPv6.....................11
3.3.3.1.2.1 Base Header Fields.......................11
3.3.3.1.2.2 Extension Headers Containing Options.....11
3.3.3.1.2.3 Extension Headers Not Containing Options.11
3.3.3.2 Padding...........................................12
3.3.3.2.1 Authentication Data Padding..................12
Kent & Atkinson Standards Track
