CBOR Object Signing and Encryption (COSE): Structures and Process
draft-ietf-cose-rfc8152bis-struct-15

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

• Versions
• 00
• 01
• 02
• 03
• 04
• 05
• 06
• 07
• 08
• 09
• 10
• 11
• 12
• 13
• 14
• 15

COSE Working Group                                             J. Schaad
Internet-Draft                                            August Cellars
Obsoletes: 8152 (if approved)                            1 February 2021
Intended status: Standards Track                                        
Expires: 5 August 2021

   CBOR Object Signing and Encryption (COSE): Structures and Process
                  draft-ietf-cose-rfc8152bis-struct-15

Abstract

   Concise Binary Object Representation (CBOR) is a data format designed
   for small code size and small message size.  There is a need for the
   ability to have basic security services defined for this data format.
   This document defines the CBOR Object Signing and Encryption (COSE)
   protocol.  This specification describes how to create and process
   signatures, message authentication codes, and encryption using CBOR
   for serialization.  This specification additionally describes how to
   represent cryptographic keys using CBOR.

   This document along with [I-D.ietf-cose-rfc8152bis-algs] obsoletes
   RFC8152.

Contributing to this document

   This note is to be removed before publishing as an RFC.

   The source for this draft is being maintained in GitHub.  Suggested
   changes should be submitted as pull requests at https://github.com/
   cose-wg/cose-rfc8152bis.  Instructions are on that page as well.
   Editorial changes can be managed in GitHub, but any substantial
   issues need to be discussed on the COSE mailing list.

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."

Schaad                    Expires 5 August 2021                 [Page 1]
Internet-Draft               COSE Structure                February 2021

   This Internet-Draft will expire on 5 August 2021.

Copyright Notice

   Copyright (c) 2021 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.

Table of Contents

   1.  Introduction  . . . . . . . . . . . . . . . . . . . . . . . .   4
     1.1.  Requirements Terminology  . . . . . . . . . . . . . . . .   6
     1.2.  Changes from RFC8152  . . . . . . . . . . . . . . . . . .   6
     1.3.  Design Changes from JOSE  . . . . . . . . . . . . . . . .   6
     1.4.  CBOR Grammar  . . . . . . . . . . . . . . . . . . . . . .   7
     1.5.  CBOR-Related Terminology  . . . . . . . . . . . . . . . .   8
     1.6.  Document Terminology  . . . . . . . . . . . . . . . . . .   9
   2.  Basic COSE Structure  . . . . . . . . . . . . . . . . . . . .  10
   3.  Header Parameters . . . . . . . . . . . . . . . . . . . . . .  13
     3.1.  Common COSE Header Parameters . . . . . . . . . . . . . .  15
   4.  Signing Objects . . . . . . . . . . . . . . . . . . . . . . .  18
     4.1.  Signing with One or More Signers  . . . . . . . . . . . .  18
     4.2.  Signing with One Signer . . . . . . . . . . . . . . . . .  20
     4.3.  Externally Supplied Data  . . . . . . . . . . . . . . . .  21
     4.4.  Signing and Verification Process  . . . . . . . . . . . .  22
   5.  Encryption Objects  . . . . . . . . . . . . . . . . . . . . .  24
     5.1.  Enveloped COSE Structure  . . . . . . . . . . . . . . . .  24
       5.1.1.  Content Key Distribution Methods  . . . . . . . . . .  26
     5.2.  Single Recipient Encrypted  . . . . . . . . . . . . . . .  26
     5.3.  How to Encrypt and Decrypt for AEAD Algorithms  . . . . .  27
     5.4.  How to Encrypt and Decrypt for AE Algorithms  . . . . . .  29
   6.  MAC Objects . . . . . . . . . . . . . . . . . . . . . . . . .  30
     6.1.  MACed Message with Recipients . . . . . . . . . . . . . .  31
     6.2.  MACed Messages with Implicit Key  . . . . . . . . . . . .  32
     6.3.  How to Compute and Verify a MAC . . . . . . . . . . . . .  33
   7.  Key Objects . . . . . . . . . . . . . . . . . . . . . . . . .  34
     7.1.  COSE Key Common Parameters  . . . . . . . . . . . . . . .  35