HMAC-SHA-2 Authentication Protocols in User-Based Security Model (USM) for SNMPv3
RFC 7860

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Internet Engineering Task Force (IETF)                    J. Merkle, Ed.
Request for Comments: 7860                     Secunet Security Networks
Obsoletes: 7630                                               M. Lochter
Category: Standards Track                                            BSI
ISSN: 2070-1721                                               April 2016

                 HMAC-SHA-2 Authentication Protocols in
               User-Based Security Model (USM) for SNMPv3

Abstract

   This document specifies several authentication protocols based on the
   SHA-2 hash functions for the User-based Security Model (USM) for
   SNMPv3 defined in RFC 3414.  It obsoletes RFC 7630, in which the MIB
   MODULE-IDENTITY value was incorrectly specified.

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/rfc7860.

Copyright Notice

   Copyright (c) 2016 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
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   the Trust Legal Provisions and are provided without warranty as
   described in the Simplified BSD License.

Merkle & Lochter             Standards Track                    [Page 1]
RFC 7860                   HMAC-SHA-2_Auth_USM                April 2016

Table of Contents

   1.  Introduction  . . . . . . . . . . . . . . . . . . . . . . . .   3
   2.  The Internet-Standard Management Framework  . . . . . . . . .   3
   3.  Conventions . . . . . . . . . . . . . . . . . . . . . . . . .   3
   4.  The HMAC-SHA-2 Authentication Protocols . . . . . . . . . . .   4
     4.1.  Deviations from the HMAC-SHA-96 Authentication Protocol .   4
     4.2.  Processing  . . . . . . . . . . . . . . . . . . . . . . .   5
       4.2.1.  Processing an Outgoing Message  . . . . . . . . . . .   6
       4.2.2.  Processing an Incoming Message  . . . . . . . . . . .   6
   5.  Key Localization and Key Change . . . . . . . . . . . . . . .   7
   6.  Structure of the MIB Module . . . . . . . . . . . . . . . . .   7
   7.  Relationship to Other MIB Modules . . . . . . . . . . . . . .   7
     7.1.  Relationship to SNMP-USER-BASED-SM-MIB  . . . . . . . . .   7
     7.2.  Relationship to SNMP-FRAMEWORK-MIB  . . . . . . . . . . .   7
     7.3.  MIB Modules Required for IMPORTS  . . . . . . . . . . . .   8
   8.  Definitions . . . . . . . . . . . . . . . . . . . . . . . . .   8
   9.  Security Considerations . . . . . . . . . . . . . . . . . . .  10
     9.1.  Use of the HMAC-SHA-2 Authentication Protocols in USM . .  10
     9.2.  Cryptographic Strength of the Authentication Protocols  .  10
     9.3.  Derivation of Keys from Passwords . . . . . . . . . . . .  11
     9.4.  Access to the SNMP-USM-HMAC-SHA2-MIB  . . . . . . . . . .  11
   10. IANA Considerations . . . . . . . . . . . . . . . . . . . . .  12
   11. References  . . . . . . . . . . . . . . . . . . . . . . . . .  12
     11.1.  Normative References . . . . . . . . . . . . . . . . . .  12
     11.2.  Informative References . . . . . . . . . . . . . . . . .  13
   Authors' Addresses  . . . . . . . . . . . . . . . . . . . . . . .  14

Merkle & Lochter             Standards Track                    [Page 2]
RFC 7860                   HMAC-SHA-2_Auth_USM                April 2016

1.  Introduction

   Within the Architecture for describing Simple Network Management
   Protocol (SNMP) Management Frameworks [RFC3411], the User-based
   Security Model (USM) [RFC3414] for SNMPv3 is defined as a Security
   Subsystem within an SNMP engine.  In RFC 3414, two different
   authentication protocols, HMAC-MD5-96 and HMAC-SHA-96, are defined
   based on the hash functions MD5 and SHA-1, respectively.

   This memo specifies new HMAC-SHA-2 authentication protocols for USM
   using a Hashed Message Authentication Code (HMAC) based on the SHA-2
   family of hash functions [SHA] and truncated to 128 bits for SHA-224,
   to 192 bits for SHA-256, to 256 bits for SHA-384, and to 384 bits for
   SHA-512.  These protocols are straightforward adaptations of the
   authentication protocols HMAC-MD5-96 and HMAC-SHA-96 to the