ECDHE_PSK with AES-GCM and AES-CCM Cipher Suites for Transport Layer Security (TLS)
draft-mattsson-tls-ecdhe-psk-aead-01

Network Working Group                                        J. Mattsson
Internet-Draft                                                D. Migault
Intended status: Standards Track                                Ericsson
Expires: January 7, 2016                                    July 6, 2015

            ECDHE_PSK with AES-GCM and AES-CCM Cipher Suites
                   for Transport Layer Security (TLS)
                  draft-mattsson-tls-ecdhe-psk-aead-01

Abstract

   This memo defines several new cipher suites for the Transport Layer
   Security (TLS) protocol.  The cipher suites are all based on the
   Ephemeral Elliptic Curve Diffie-Hellman with Pre-Shared Key
   (ECDHE_PSK) key exchange together with the Authenticated Encryption
   with Associated Data (AEAD) algorithms AES-GCM and AES-CCM.  PSK
   provides light and efficient authentication, ECDHE provides perfect
   forward secrecy, and AES-GCM and AES-CCM provides encryption and
   integrity protection.

Status of This Memo

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   This Internet-Draft will expire on January 7, 2016.

Copyright Notice

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   to this document.  Code Components extracted from this document must
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Table of Contents

   1.  Introduction  . . . . . . . . . . . . . . . . . . . . . . . .   2
   2.  ECDHE_PSK with AES-GCM and AES-CCM Cipher Suites  . . . . . .   3
   3.  Applicable TLS Versions . . . . . . . . . . . . . . . . . . .   3
   4.  IANA Considerations . . . . . . . . . . . . . . . . . . . . .   3
   5.  Security Considerations . . . . . . . . . . . . . . . . . . .   4
   6.  Acknowledgements  . . . . . . . . . . . . . . . . . . . . . .   4
   7.  References  . . . . . . . . . . . . . . . . . . . . . . . . .   4
   Authors' Addresses  . . . . . . . . . . . . . . . . . . . . . . .   5

1.  Introduction

   This document defines new cipher suites that provide Pre-Shared Key
   (PSK) authentication, Perfect Forward Secrecy (PFS), and
   Authenticated Encryption with Associated Data (AEAD).

   Pre-Shared Key (PSK) Authentication is widely used in many scenarios.
   One deployment is 3GPP networks where pre-shared keys are used to
   authenticate both subscriber and network.  Another deployment is
   Internet of Things where PSK authentication is often preferred for
   performance and energy efficiency reasons.  In both scenarios the
   endpoints are owned/controlled by a party that provisions the pre-
   shared keys and makes sure that they provide a high level of entropy.

   Perfect Forward Secrecy (PFS) is a strongly recommended feature in
   security protocol design and can be accomplished by using an
   ephemeral Diffie-Hellman key exchange method.  Ephemeral Elliptic
   Curve Diffie-Hellman (ECDHE) provides PFS with excellent performance
   and small key sizes.  ECDHE is mandatory to implement in both HTTP/2
   [RFC7540] and CoAP [RFC7252].

   AEAD algorithms that combine encryption and integrity protection are
   strongly recommended [RFC7525], and non-AEAD algorithms will likely
   be forbidden to use in TLS1.3.  The AEAD algorithms considered in
   this document are AES-CCM and AES-GCM.  The use of AES-CCM in TLS is
   defined in [RFC6655] and the use of AES-GCM is defined [RFC5288].

   [RFC4279] defines Pre-Shared Key (PSK) cipher suites for TLS but does
   not consider Elliptic Curve Cryptography.  [RFC5489] introduces
   Elliptic Curve Cryptography for TLS but does not consider PSK
   authentication.  [RFC5487] describes the use of AES-GCM in
   combination with PSK authentication, but does not consider ECDHE.

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   [RFC5489] describes the use of PSK in combination with ECDHE but does
   not consider AES-GCM or AES-CCM.

2.  ECDHE_PSK with AES-GCM and AES-CCM Cipher Suites

   The cipher suites defined in this document are based on the AES-GCM
   and AES-CCM Authenticated Encryption with Associated Data (AEAD)
   algorithms AEAD_AES_128_GCM, AEAD_AES_256_GCM, AEAD_AES_128_CCM, and
   AEAD_AES_256_CCM described in [RFC5116].  The following cipher suites
   are defined:

    TLS_ECDHE_PSK_WITH_AES_128_GCM                         = {TDB0,TDB1};
    TLS_ECDHE_PSK_WITH_AES_256_GCM                         = {TDB2,TDB3};
    TLS_ECDHE_PSK_WITH_AES_128_CCM_8                       = {TDB4,TDB5};
    TLS_ECDHE_PSK_WITH_AES_128_CCM                         = {TDB6,TDB7};
    TLS_ECDHE_PSK_WITH_AES_256_CCM                         = {TDB8,TDB9};

   These cipher suites make use of the default TLS 1.2 Pseudorandom
   Function (PRF), which uses HMAC with the SHA-256 hash function.
   Clients and Servers MUST NOT negotiate curves of less than 255 bits
   and the Pre-Shared-Keys MUST NOT have an entropy of less than 128
   bits.

3.  Applicable TLS Versions

   These cipher suites make use of the authenticated encryption with
   additional data (AEAD) defined in TLS 1.2 [RFC5246].  Earlier
   versions of TLS do not have support for AEAD and consequently, these
   cipher suites MUST NOT be negotiated in TLS versions prior to 1.2.
   Clients MUST NOT offer these cipher suites if they do not offer TLS
   1.2 or later.  Servers, which select an earlier version of TLS MUST
   NOT select one of these cipher suites.  A client MUST treat the
   selection of these cipher suites in combination with a version of TLS
   that does not support AEAD (i.e., TLS 1.1 or earlier) as an error and
   generate a fatal 'illegal_parameter' TLS alert.

4.  IANA Considerations

   This document defines the following new cipher suites, whose values
   have been assigned in the TLS Cipher Suite Registry defined by
   [RFC5246].

   TLS_ECDHE_PSK_WITH_AES_128_GCM                         = {TDB0,TDB1};
   TLS_ECDHE_PSK_WITH_AES_256_GCM                         = {TDB2,TDB3};
   TLS_ECDHE_PSK_WITH_AES_128_CCM_8                       = {TDB4,TDB5};
   TLS_ECDHE_PSK_WITH_AES_128_CCM                         = {TDB6,TDB7};
   TLS_ECDHE_PSK_WITH_AES_256_CCM                         = {TDB8,TDB9};

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5.  Security Considerations

   Most of the security considerations in [RFC5246], [RFC4279],
   [RFC4492], [RFC5288], [RFC5489], and [RFC6655] apply to this document
   as well.  The cipher suites defined in this document provides perfect
   forward secrecy.

6.  Acknowledgements

   The authors would like to thank Ilari Liusvaara for valuable comments
   and feedback.

7.  References

   [RFC4279]  Eronen, P. and H. Tschofenig, "Pre-Shared Key Ciphersuites
              for Transport Layer Security (TLS)", RFC 4279, December
              2005.

   [RFC4492]  Blake-Wilson, S., Bolyard, N., Gupta, V., Hawk, C., and B.
              Moeller, "Elliptic Curve Cryptography (ECC) Cipher Suites
              for Transport Layer Security (TLS)", RFC 4492, May 2006.

   [RFC5116]  McGrew, D., "An Interface and Algorithms for Authenticated
              Encryption", RFC 5116, January 2008.

   [RFC5246]  Dierks, T. and E. Rescorla, "The Transport Layer Security
              (TLS) Protocol Version 1.2", RFC 5246, August 2008.

   [RFC5288]  Salowey, J., Choudhury, A., and D. McGrew, "AES Galois
              Counter Mode (GCM) Cipher Suites for TLS", RFC 5288,
              August 2008.

   [RFC5487]  Badra, M., "Pre-Shared Key Cipher Suites for TLS with SHA-
              256/384 and AES Galois Counter Mode", RFC 5487, March
              2009.

   [RFC5489]  Badra, M. and I. Hajjeh, "ECDHE_PSK Cipher Suites for
              Transport Layer Security (TLS)", RFC 5489, March 2009.

   [RFC6655]  McGrew, D. and D. Bailey, "AES-CCM Cipher Suites for
              Transport Layer Security (TLS)", RFC 6655, July 2012.

   [RFC7252]  Shelby, Z., Hartke, K., and C. Bormann, "The Constrained
              Application Protocol (CoAP)", RFC 7252, June 2014.

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   [RFC7525]  Sheffer, Y., Holz, R., and P. Saint-Andre,
              "Recommendations for Secure Use of Transport Layer
              Security (TLS) and Datagram Transport Layer Security
              (DTLS)", BCP 195, RFC 7525, May 2015.

   [RFC7540]  Belshe, M., Peon, R., and M. Thomson, "Hypertext Transfer
              Protocol Version 2 (HTTP/2)", RFC 7540, May 2015.

Authors' Addresses

   John Mattsson
   Ericsson AB
   SE-164 80 Stockholm
   Sweden

   Email: john.mattsson@ericsson.com

   Daniel Migault
   Ericsson
   8400 boulevard Decarie
   Montreal, QC   H4P 2N2
   Canada

   Phone: +1 514-452-2160
   Email: daniel.migault@ericsson.com

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