ECDHE_PSK Cipher Suites for Transport Layer Security (TLS)
RFC 5489

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Network Working Group                                           M. Badra
Request for Comments: 5489                         CNRS/LIMOS Laboratory
Category: Informational                                        I. Hajjeh
                                                              INEOVATION
                                                              March 2009

       ECDHE_PSK Cipher Suites for Transport Layer Security (TLS)

Status of This Memo

   This memo provides information for the Internet community.  It does
   not specify an Internet standard of any kind.  Distribution of this
   memo is unlimited.

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Abstract

   This document extends RFC 4279, RFC 4492, and RFC 4785 and specifies
   a set of cipher suites that use a pre-shared key (PSK) to
   authenticate an Elliptic Curve Diffie-Hellman exchange with Ephemeral
   keys (ECDHE).  These cipher suites provide Perfect Forward Secrecy
   (PFS).

Badra & Hajjeh               Informational                      [Page 1]
RFC 5489            ECDHE_PSK Cipher Suites for TLS           March 2009

Table of Contents

   1. Introduction ....................................................2
      1.1. Applicability Statement ....................................3
      1.2. Conventions Used in This Document ..........................3
   2. ECDHE_PSK Key Exchange Algorithm ................................3
   3. ECDHE_PSK-Based Cipher Suites ...................................4
      3.1. ECDHE_PSK Cipher Suites Using the SHA-1 Hash ...............4
      3.2. ECDHE_PSK Cipher Suites Using SHA-2 Hashes .................4
   4. ECDHE_PSK-Based Cipher Suites with NULL Encryption ..............5
      4.1. ECDHE_PSK Cipher Suite Using the SHA-1 Hash with
           NULL Encryption ............................................5
      4.2. ECDHE_PSK Cipher Suites Using SHA-2 Hashes with
           NULL Encryption ............................................5
   5. Security Considerations .........................................5
   6. IANA Considerations .............................................6
   7. Acknowledgments .................................................6
   8. Normative References ............................................6

1.  Introduction

   RFC 4279 specifies cipher suites for supporting TLS using pre-shared
   symmetric keys that (a) use only symmetric key operations for
   authentication, (b) use a Diffie-Hellman exchange authenticated with
   a pre-shared key (PSK), or (c) combine public key authentication of
   the server with pre-shared key authentication of the client.

   RFC 4785 specifies authentication-only cipher suites (with no
   encryption).  These cipher suites are useful when authentication and
   integrity protection is desired, but confidentiality is not needed or
   not permitted.

   RFC 4492 defines a set of Elliptic Curve Cryptography (ECC)-based
   cipher suites for TLS and describes the use of ECC certificates for
   client authentication.  In particular, it specifies the use of
   Elliptic Curve Diffie-Hellman (ECDH) key agreement in a TLS handshake
   and the use of the Elliptic Curve Digital Signature Algorithm (ECDSA)
   as a new authentication mechanism.

   This document specifies a set of cipher suites that use a PSK to
   authenticate an ECDH exchange.  These cipher suites provide Perfect
   Forward Secrecy.  Some of these cipher suites provide authentication
   only.

   The reader is expected to become familiar with RFC 4279, RFC 4492,
   and RFC 4785 prior to studying this document.

Badra & Hajjeh               Informational                      [Page 2]
RFC 5489            ECDHE_PSK Cipher Suites for TLS           March 2009

1.1.  Applicability Statement

   The cipher suites defined in this document can be negotiated,
   whatever the negotiated TLS version is.