HMAC authentication for the Babel routing protocol
draft-ietf-babel-hmac-02

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Network Working Group                                              C. Do
Internet-Draft                                            W. Kolodziejak
Obsoletes: 7298 (if approved)                              J. Chroboczek
Updates: 6126bis (if approved)         IRIF, University of Paris-Diderot
Intended status: Standards Track                       December 23, 2018
Expires: June 26, 2019

           HMAC authentication for the Babel routing protocol
                        draft-ietf-babel-hmac-02

Abstract

   This document describes a cryptographic authentication for the Babel
   routing protocol that has provisions for replay avoidance.  This
   document updates RFC 6126bis and obsoletes RFC 7298.

Status of This Memo

   This Internet-Draft is submitted in full conformance with the
   provisions of BCP 78 and BCP 79.

   Internet-Drafts are working documents of the Internet Engineering
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   This Internet-Draft will expire on June 26, 2019.

Copyright Notice

   Copyright (c) 2018 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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   described in the Simplified BSD License.

Do, et al.                Expires June 26, 2019                 [Page 1]
Internet-Draft        HMAC authentication for Babel        December 2018

Table of Contents

   1.  Introduction  . . . . . . . . . . . . . . . . . . . . . . . .   2
     1.1.  Applicability . . . . . . . . . . . . . . . . . . . . . .   3
     1.2.  Assumptions and security properties . . . . . . . . . . .   3
     1.3.  Specification of Requirements . . . . . . . . . . . . . .   4
   2.  Conceptual overview of the protocol . . . . . . . . . . . . .   4
   3.  Data Structures . . . . . . . . . . . . . . . . . . . . . . .   5
     3.1.  The Interface Table . . . . . . . . . . . . . . . . . . .   5
     3.2.  The Neighbour table . . . . . . . . . . . . . . . . . . .   6
   4.  Protocol Operation  . . . . . . . . . . . . . . . . . . . . .   6
     4.1.  HMAC computation  . . . . . . . . . . . . . . . . . . . .   6
     4.2.  Packet Transmission . . . . . . . . . . . . . . . . . . .   7
     4.3.  Packet Reception  . . . . . . . . . . . . . . . . . . . .   8
     4.4.  Expiring per-neighbour state  . . . . . . . . . . . . . .  10
   5.  Packet Format . . . . . . . . . . . . . . . . . . . . . . . .  11
     5.1.  HMAC TLV  . . . . . . . . . . . . . . . . . . . . . . . .  11
     5.2.  PC TLV  . . . . . . . . . . . . . . . . . . . . . . . . .  11
     5.3.  Challenge Request TLV . . . . . . . . . . . . . . . . . .  12
     5.4.  Challenge Reply TLV . . . . . . . . . . . . . . . . . . .  12
   6.  Security Considerations . . . . . . . . . . . . . . . . . . .  13
   7.  IANA Considerations . . . . . . . . . . . . . . . . . . . . .  14
   8.  Acknowledgments . . . . . . . . . . . . . . . . . . . . . . .  14
   9.  References  . . . . . . . . . . . . . . . . . . . . . . . . .  14
     9.1.  Normative References  . . . . . . . . . . . . . . . . . .  14
     9.2.  Informational References  . . . . . . . . . . . . . . . .  15
   Appendix A.  Incremental deployment and key rotation  . . . . . .  15
   Appendix B.  Changes from previous versions . . . . . . . . . . .  16
     B.1.  Changes since draft-ietf-babel-hmac-00  . . . . . . . . .  16
     B.2.  Changes since draft-ietf-babel-hmac-00  . . . . . . . . .  16
   Authors' Addresses  . . . . . . . . . . . . . . . . . . . . . . .  16

1.  Introduction

   By default, the Babel routing protocol trusts the information
   contained in every UDP packet it receives on the Babel port.  An
   attacker can redirect traffic to itself or to a different node in the
   network, causing a variety of potential issues.  In particular, an
   attacker might:

   o  spoof a Babel packet, and redirect traffic by announcing a smaller
      metric, a larger seqno, or a longer prefix;

   o  spoof a malformed packet, which could cause an insufficiently
      robust implementation to crash or interfere with the rest of the
      network;