Endpoint Message Authentication for AODV Route Messages
draft-perkins-manet-aodv-e2esec-01.txt

Abstract

This document specifies a new type extension to enable RFC 7182 authentication mechanism to be used for authenticating AODVv2 route messages. The document also specifies a new message TLV for AODVv2 and, potentially, other reactive protocols. Both mechanisms allow the endpoints of a newly discovered route to be assured that they were the originator of the RREQ and responder producing the RREP respectively.

Status of This Memo

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

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This Internet-Draft will expire on November 4, 2016.

Copyright Notice

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Table of Contents

• 1. Introduction
• 2. Terminology
• 3. ICV Message Extensions for AODVv2
• 4. RFC 7182 method for computing Message TLV ICV-data
• 5. RFC 4868 method computing Message TLV ICV-data
• 6. Security Considerations
• 7. IANA Considerations
• 8. Acknowledgement
• 9. Normative References
• Author's Address

1. Introduction

In certain cases during route discovery, it would be useful for the source and destination nodes for the discovered routes to verify each others' participation in the route discovery process, and thus that a route was indeed established between them. This does not guarantee a functioning route because malicious intermediate nodes might still misdirect or drop traffic.

2. Terminology

The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT", "SHOULD", "SHOULD NOT", "RECOMMENDED", "NOT RECOMMENDED", "MAY", and "OPTIONAL" in this document are to be interpreted as described in [RFC2119].

This document also uses some terminology from [RFC5444], [RFC7182] and AODVv2 [I-D.ietf-manet-aodvv2].

3. ICV Message Extensions for AODVv2

For the computations specified in this document, the input data (i.e., content) is the the concatenation of the following data contained in the AODVv2 [I-D.ietf-manet-aodvv2] message, in this order:

• OrigAddr
• TargAddr
• PrefixLengthList if present in the message
• OrigSeqNum if present in the message
• TargSeqNum if present in the message
• MetricType

4. RFC 7182 method for computing Message TLV ICV-data

The authentication algorithm uses a new type extension to allow AODVv2 to compute the ICV-data on the selected input data. In order to conform to the specification within RFC 7182 [RFC7182] for a new type extension, this document specifies the following details.

The input data for the computation is as specified in Section 3, padded up to the nearest multiple of 16 bytes. The output of the computation is truncated to a 128-bit authenticator value which is used for the ICV-data field of the ICV Message TLV. Every AODVv2 conforming to this specification MUST support AES-CMAC as the cryptographic algorithm.

5. RFC 4868 method computing Message TLV ICV-data

The authentication algorithm uses HMAC-SHA-256-128 [RFC4868] to compute authentication data.

The output of the computation is a 128-bit authenticator value which is used for the value field of the E2E Message TLV ICV-data.

The format for the E2E Message TLV ICV-data is shown in Figure 1.

     0                   1                   2                   3
     0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
    +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
    |      Type     |    Flags      |           Reserved            |
    +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
    :               Message TLV ICV-data (128 bits)                 :
    +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+