Datagram Transport Layer Security (DTLS) as a Transport Layer for RADIUS
RFC 7360

Internet Engineering Task Force (IETF)                          A. DeKok
Request for Comments: 7360                                    FreeRADIUS
Category: Experimental                                    September 2014
ISSN: 2070-1721

                Datagram Transport Layer Security (DTLS)
                    as a Transport Layer for RADIUS

Abstract

   The RADIUS protocol defined in RFC 2865 has limited support for
   authentication and encryption of RADIUS packets.  The protocol
   transports data in the clear, although some parts of the packets can
   have obfuscated content.  Packets may be replayed verbatim by an
   attacker, and client-server authentication is based on fixed shared
   secrets.  This document specifies how the Datagram Transport Layer
   Security (DTLS) protocol may be used as a fix for these problems.  It
   also describes how implementations of this proposal can coexist with
   current RADIUS systems.

Status of This Memo

   This document is not an Internet Standards Track specification; it is
   published for examination, experimental implementation, and
   evaluation.

   This document defines an Experimental Protocol for the Internet
   community.  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).  Not
   all documents approved by the IESG are a candidate for any level of
   Internet Standard; see 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/rfc7360.

DeKok                         Experimental                      [Page 1]
RFC 7360          DTLS as a Transport Layer for RADIUS    September 2014

Copyright Notice

   Copyright (c) 2014 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
   (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.

DeKok                         Experimental                      [Page 2]
RFC 7360          DTLS as a Transport Layer for RADIUS    September 2014

Table of Contents

   1. Introduction ....................................................4
      1.1. Terminology ................................................5
      1.2. Requirements Language ......................................5
      1.3. Document Status ............................................5
   2. Building on Existing Foundations ................................6
      2.1. Changes to RADIUS ..........................................7
      2.2. Similarities with RADIUS/TLS ...............................8
           2.2.1. Changes from RADIUS/TLS to RADIUS/DTLS ..............8
   3. Interaction with RADIUS/UDP .....................................9
      3.1. DTLS Port and Packet Types ................................10
      3.2. Server Behavior ...........................................10
   4. Client Behavior ................................................11
   5. Session Management .............................................12
      5.1. Server Session Management .................................12
           5.1.1. Session Opening and Closing ........................13
      5.2. Client Session Management .................................15
   6. Implementation Guidelines ......................................16
      6.1. Client Implementations ....................................17
      6.2. Server Implementations ....................................18
   7. Diameter Considerations ........................................18
   8. IANA Considerations ............................................18
   9. Implementation Status ..........................................18
      9.1. Radsecproxy ...............................................19
      9.2. jradius ...................................................19
   10. Security Considerations .......................................19
      10.1. Crypto-Agility ...........................................20
      10.2. Legacy RADIUS Security ...................................21
      10.3. Resource Exhaustion ......................................22