NEA Asokan Attack Analysis
draft-ietf-nea-asokan-00

The information below is for an old version of the document
Document Type Active Internet-Draft (nea WG)
Last updated 2012-04-26
Replaces draft-salowey-nea-asokan
Stream IETF
Intended RFC status (None)
Formats plain text pdf html
Stream WG state WG Document
Document shepherd None
IESG IESG state I-D Exists
Telechat date
Responsible AD (None)
Send notices to (None)
Network Working Group                                        J. Salowey
Internet Draft                                            Cisco Systems
Intended status: Informational                                 S. Hanna
Expires: October 2012                                  Juniper Networks
                                                         April 26, 2012

                        NEA Asokan Attack Analysis
                       draft-ietf-nea-asokan-00.txt

Abstract

   The Network Endpoint Assessment protocols are subject to a subtle
   forwarding attack that has become known as the NEA Asokan Attack.
   This document describes the attack and countermeasures that may be
   mounted.

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
   Task Force (IETF), its areas, and its working groups.  Note that
   other groups may also distribute working documents as Internet-
   Drafts.

   Internet-Drafts are draft documents valid for a maximum of six
   months and may be updated, replaced, or obsoleted by other documents
   at any time.  It is inappropriate to use Internet-Drafts as
   reference material or to cite them other than as "work in progress."

   The list of current Internet-Drafts can be accessed at
   http://www.ietf.org/ietf/1id-abstracts.txt

   The list of Internet-Draft Shadow Directories can be accessed at
   http://www.ietf.org/shadow.html

   This Internet-Draft will expire on October 26, 2012.

Copyright Notice

   Copyright (c) 2012 IETF Trust and the persons identified as the
   document authors. All rights reserved.

Salowey                Expires October 26, 2012                [Page 1]
Internet-Draft        NEA Asokan Attack Analysis             April 2012

   This document is subject to BCP 78 and the IETF Trust's Legal
   Provisions Relating to IETF Documents
   (http://trustee.ietf.org/license-info) in effect on the date of
   publication of this document. Please review these documents
   carefully, as they describe your rights and restrictions with
   respect to this document.  Code Components extracted from this
   document must include Simplified BSD License text as described in
   Section 4.e of the Trust Legal Provisions and are provided without
   warranty as described in the Simplified BSD License.

Table of Contents

   1. Introduction...................................................2
   2. NEA Asokan Attack Explained....................................2
   3. Lying Endpoints................................................4
   4. Countermeasures Against The NEA Asokan Attack..................4
      4.1. Identity Binding..........................................4
      4.2. Cryptographic Binding.....................................5
         4.2.1. Binding Options......................................5
            4.2.1.1. Information from the TLS Tunnel.................5
            4.2.1.2. TLS Cipher Suites...............................5
            4.2.1.3. Using Additional Key Material from TLS..........5
            4.2.1.4. EMA assumptions.................................6
   5. Conclusions....................................................6
   6. IANA Considerations............................................6
   7. Security Considerations........................................6
   8. References.....................................................6
      8.1. Informative References....................................6
   9. Acknowledgments................................................7

1. Introduction

   The Network Endpoint Assessment protocols are subject to a subtle
   forwarding attack that has become known as the NEA Asokan Attack.
   This document describes the attack and countermeasures that may be
   mounted. The NEA WG has included several of these countermeasures in
   PT-TLS [5] and PT-EAP [6].

2. NEA Asokan Attack Explained

   The NEA Asokan Attack is a variation on an attack described in a
   2002 paper written by Asokan, Niemi, and Nyberg [1]. Figure 1
   depicts one version of the original Asokan attack. This attack
   involves tricking an authorized user into authenticating to a decoy
   AAA server, which forwards the authentication protocol from one

Salowey                Expires October 26, 2012                [Page 2]
Internet-Draft        NEA Asokan Attack Analysis             April 2012

   tunnel to another, tricking a AAA server into believing these
   messages came from the attacker and granting access to him.

                            +-------------+ ========== +----------+
                            |   Attacker  |-AuthProto--|AAA Server|
Show full document text