Handling Large Certificates and Long Certificate Chains in TLS-based EAP Methods
draft-ms-emu-eaptlscert-02

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Network Working Group                                           M. Sethi
Internet-Draft                                               J. Mattsson
Intended status: Informational                                  Ericsson
Expires: September 7, 2019                                     S. Turner
                                                                   sn3rd
                                                           March 6, 2019

        Handling Large Certificates and Long Certificate Chains
                        in TLS-based EAP Methods
                       draft-ms-emu-eaptlscert-02

Abstract

   EAP-TLS and other TLS-based EAP methods are widely deployed and used
   for network access authentication.  Large certificates and long
   certificate chains combined with authenticators that drop an EAP
   session after only 40 - 50 packets is a major deployment problem.
   This memo looks at the this problem in detail and describes the
   potential solutions available.

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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   Internet-Drafts are draft documents valid for a maximum of six months
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   time.  It is inappropriate to use Internet-Drafts as reference
   material or to cite them other than as "work in progress."

   This Internet-Draft will expire on September 7, 2019.

Copyright Notice

   Copyright (c) 2019 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
   Provisions Relating to IETF Documents
   (https://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

Sethi, et al.           Expires September 7, 2019               [Page 1]
Internet-Draft    Certificates in TLS-based EAP Methods       March 2019

   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.  Terminology . . . . . . . . . . . . . . . . . . . . . . . . .   3
   3.  Experience with Deployments . . . . . . . . . . . . . . . . .   3
   4.  Handling of Large Certificates and Long Certificate Chains  .   4
     4.1.  Updating Certificates and Certificate Chains  . . . . . .   4
       4.1.1.  Guidelines for certificates . . . . . . . . . . . . .   5
     4.2.  Updating TLS and EAP-TLS Code . . . . . . . . . . . . . .   6
       4.2.1.  Pre-distributing and Omitting CA Certificates . . . .   6
       4.2.2.  Caching Certificates  . . . . . . . . . . . . . . . .   6
       4.2.3.  Compressing Certificates  . . . . . . . . . . . . . .   7
     4.3.  Updating Authenticators (Access Points) . . . . . . . . .   7
   5.  IANA Considerations . . . . . . . . . . . . . . . . . . . . .   7
   6.  Security Considerations . . . . . . . . . . . . . . . . . . .   7
   7.  References  . . . . . . . . . . . . . . . . . . . . . . . . .   7
     7.1.  Normative References  . . . . . . . . . . . . . . . . . .   7
     7.2.  Informative References  . . . . . . . . . . . . . . . . .   8
   Acknowledgements  . . . . . . . . . . . . . . . . . . . . . . . .   9
   Authors' Addresses  . . . . . . . . . . . . . . . . . . . . . . .   9

1.  Introduction

   The Extensible Authentication Protocol (EAP), defined in [RFC3748],
   provides a standard mechanism for support of multiple authentication
   methods.  EAP-Transport Layer Security (EAP-TLS) [RFC5216]
   [I-D.ietf-emu-eap-tls13] relies on TLS [RFC8446] to provide strong
   mutual authentication with certificates [RFC5280] and is widely
   deployed and often used for network access authentication.

   TLS certificates are often relatively large, and the certificate
   chains are often long.  Unlike the use of TLS on the web, where
   typically only the TLS server is authenticated; EAP-TLS deployments
   typically authenticates both the EAP peer and the EAP server.  Also,
   from deployment experience, EAP peers typically have longer
   certificate chains than servers.  Therefore, EAP-TLS authentication
   usually involve significantly more bytes than when TLS is used as
   part of HTTPS.

   As the EAP fragment size in typical deployments are just 1000 - 1500
   bytes, the EAP-TLS authentication needs to be fragmented into many
   smaller packets for transportation over the lower layers.  Such