Ephemeral Diffie-Hellman Over COSE (EDHOC)
draft-selander-lake-edhoc-00

Document Type Active Internet-Draft (individual)
Last updated 2019-11-04
Replaces draft-selander-ace-cose-ecdhe
Stream (None)
Intended RFC status (None)
Formats plain text xml pdf htmlized bibtex
Stream Stream state (No stream defined)
Consensus Boilerplate Unknown
RFC Editor Note (None)
IESG IESG state I-D Exists
Telechat date
Responsible AD (None)
Send notices to (None)
Network Working Group                                        G. Selander
Internet-Draft                                               J. Mattsson
Intended status: Standards Track                            F. Palombini
Expires: May 7, 2020                                         Ericsson AB
                                                       November 04, 2019

               Ephemeral Diffie-Hellman Over COSE (EDHOC)
                      draft-selander-lake-edhoc-00

Abstract

   This document specifies Ephemeral Diffie-Hellman Over COSE (EDHOC), a
   very compact, and lightweight authenticated Diffie-Hellman key
   exchange with ephemeral keys.  EDHOC provides mutual authentication,
   perfect forward secrecy, and identity protection.  EDHOC is intended
   for usage in constrained scenarios and a main use case is to
   establish an OSCORE security context.  By reusing COSE for
   cryptography, CBOR for encoding, and CoAP for transport, the
   additional code footprint can be kept very low.

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).  Note that other groups may also distribute
   working documents as Internet-Drafts.  The list of current Internet-
   Drafts is at https://datatracker.ietf.org/drafts/current/.

   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."

   This Internet-Draft will expire on May 7, 2020.

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

Selander, et al.           Expires May 7, 2020                  [Page 1]
Internet-Draft Ephemeral Diffie-Hellman Over COSE (EDHOC)  November 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  . . . . . . . . . . . . . . . . . . . . . . . .   3
     1.1.  Rationale for EDHOC . . . . . . . . . . . . . . . . . . .   5
     1.2.  Terminology and Requirements Language . . . . . . . . . .   6
   2.  Background  . . . . . . . . . . . . . . . . . . . . . . . . .   6
   3.  EDHOC Overview  . . . . . . . . . . . . . . . . . . . . . . .   8
     3.1.  Cipher Suites . . . . . . . . . . . . . . . . . . . . . .   9
     3.2.  Ephemeral Public Keys . . . . . . . . . . . . . . . . . .   9
     3.3.  Key Derivation  . . . . . . . . . . . . . . . . . . . . .  10
   4.  EDHOC Authenticated with Signature Keys . . . . . . . . . . .  12
     4.1.  Overview  . . . . . . . . . . . . . . . . . . . . . . . .  12
     4.2.  EDHOC Message 1 . . . . . . . . . . . . . . . . . . . . .  14
     4.3.  EDHOC Message 2 . . . . . . . . . . . . . . . . . . . . .  16
     4.4.  EDHOC Message 3 . . . . . . . . . . . . . . . . . . . . .  19
   5.  EDHOC Authenticated with Symmetric Keys . . . . . . . . . . .  22
     5.1.  Overview  . . . . . . . . . . . . . . . . . . . . . . . .  22
     5.2.  EDHOC Message 1 . . . . . . . . . . . . . . . . . . . . .  23
     5.3.  EDHOC Message 2 . . . . . . . . . . . . . . . . . . . . .  23
     5.4.  EDHOC Message 3 . . . . . . . . . . . . . . . . . . . . .  24
   6.  EDHOC Authenticated with Static Diffie-Hellman Keys . . . . .  24
     6.1.  Overview  . . . . . . . . . . . . . . . . . . . . . . . .  24
     6.2.  EDHOC Message 1 . . . . . . . . . . . . . . . . . . . . .  25
     6.3.  EDHOC Message 2 . . . . . . . . . . . . . . . . . . . . .  25
     6.4.  EDHOC Message 3 . . . . . . . . . . . . . . . . . . . . .  26
     6.5.  EDHOC-Exporter Interface  . . . . . . . . . . . . . . . .  26
     6.6.  Security Considerations . . . . . . . . . . . . . . . . .  26
     6.7.  Message Sizes . . . . . . . . . . . . . . . . . . . . . .  27
   7.  Error Handling  . . . . . . . . . . . . . . . . . . . . . . .  27
     7.1.  EDHOC Error Message . . . . . . . . . . . . . . . . . . .  27
   8.  Transferring EDHOC and Deriving Application Keys  . . . . . .  29
     8.1.  Transferring EDHOC in CoAP  . . . . . . . . . . . . . . .  29
     8.2.  Transferring EDHOC over Other Protocols . . . . . . . . .  32
   9.  Security Considerations . . . . . . . . . . . . . . . . . . .  32
     9.1.  Security Properties . . . . . . . . . . . . . . . . . . .  32
Show full document text