Chacha derived AEAD algorithms in JSON Object Signing and Encryption (JOSE)
draft-amringer-jose-chacha-02

• Status
• IESG evaluation record
• IESG writeups
• Email expansions
• History

• Versions
• 00
• 01
• 02

(No Working Group)                                           G. Amringer
Internet-Draft                                           January 9, 2020
Intended status: Informational
Expires: July 12, 2020

  Chacha derived AEAD algorithms in JSON Object Signing and Encryption
                                 (JOSE)
                     draft-amringer-jose-chacha-02

Abstract

   This document defines how to use the AEAD algorithms
   "AEAD_XCHACHA20_POLY1305" and "AEAD_CHACHA20_POLY1305" from [RFC8439]
   and [I-D.irtf-cfrg-xchacha] in JSON Object Signing and Encryption
   (JOSE).

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 July 12, 2020.

Copyright Notice

   Copyright (c) 2020 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
   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.

Amringer                  Expires July 12, 2020                 [Page 1]
Internet-Draft                                              January 2020

Table of Contents

   1.  Introduction  . . . . . . . . . . . . . . . . . . . . . . . .   2
     1.1.  Notation and Conventions  . . . . . . . . . . . . . . . .   2
   2.  Key Encryption  . . . . . . . . . . . . . . . . . . . . . . .   3
     2.1.  Algorithms  . . . . . . . . . . . . . . . . . . . . . . .   3
     2.2.  Header Parameters Used for Key Encryption . . . . . . . .   3
       2.2.1.  "iv" (Initialization Vector) Header Parameter . . . .   3
       2.2.2.  "tag" (Authentication Tag) Header Parameter . . . . .   4
   3.  Key Agreement with Elliptic Curve Diffie-Hellman Ephemeral
       Static  . . . . . . . . . . . . . . . . . . . . . . . . . . .   4
   4.  Content Encryption  . . . . . . . . . . . . . . . . . . . . .   4
     4.1.  Algorithms  . . . . . . . . . . . . . . . . . . . . . . .   4
   5.  IANA Considerations . . . . . . . . . . . . . . . . . . . . .   5
   6.  References  . . . . . . . . . . . . . . . . . . . . . . . . .   6
     6.1.  Normative References  . . . . . . . . . . . . . . . . . .   6
     6.2.  URIs  . . . . . . . . . . . . . . . . . . . . . . . . . .   7
   Appendix A.  Example using XC20PKW  . . . . . . . . . . . . . . .   7
   Appendix B.  Example using ECDH-ES+XC20PKW  . . . . . . . . . . .   8
   Author's Address  . . . . . . . . . . . . . . . . . . . . . . . .  11

1.  Introduction

   The Internet Research Task Force (IRTF) Crypto Forum Research Group
   (CFRG) defined the ChaCha20 and Poly1305 algorithms to be used in
   IETF protocols both independantly and as an AEAD construction
   ([RFC8439]).  It has also been presented with a definition of an
   eXtended-nonce variant ([I-D.irtf-cfrg-xchacha]) for use in stateless
   contexts.  This document defines how to use those algorithms in JOSE
   in an interoperable manner.

   This document defines the conventions to use in the context of
   [RFC7516], and [RFC7517].

1.1.  Notation and Conventions

   The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT",
   "SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY", and "OPTIONAL" in this
   document are to be interpreted as described in [RFC2119].

   The JOSE key format ("JSON Web Key (JWK)") is defined by [RFC7517]
   and thumbprints for it ("JSON Web Key (JWK) Thumbprint") in
   [RFC7638].

Amringer                  Expires July 12, 2020                 [Page 2]
Internet-Draft                                              January 2020

2.  Key Encryption

2.1.  Algorithms

   This section defines the specifics of encrypting a JWE Content
   Encryption Key (CEK) with AEAD_CHACHA20_POLY1305 [RFC8439] and
   AEAD_XCHACHA20_POLY1305 [I-D.irtf-cfrg-xchacha].

   Use of an Initialization Vector (IV) is REQUIRED with this algorithm.
   The IV is represented in base64url-encoded form as the "iv"
   (initialization vector) Header Parameter value.

   The Additional Authenticated Data value used is the empty octet