Map-like data in CBOR and CDDL
draft-bormann-cbor-cddl-map-like-data-00
Network Working Group C. Bormann, Ed.
Internet-Draft Universität Bremen TZI
Intended status: Informational B. Moran
Expires: 6 October 2021 Arm Limited
H. Birkholz
Fraunhofer SIT
E. Cormier
4 April 2021
Map-like data in CBOR and CDDL
draft-bormann-cbor-cddl-map-like-data-00
Abstract
The Concise Binary Object Representation (CBOR, RFC 8949) is a data
format whose design goals include the possibility of extremely small
code size, fairly small message size, and extensibility without the
need for version negotiation.
Basic CBOR supports unordered maps free of duplicate keys, similar to
the way JSON defines JSON objects (RFC 8259). Using the CBOR
extension point of tags, tags for a selection of variants of maps and
multimaps have been registered, but gaps remain. The present
document defines a consolidated set of CBOR tags for map-like data
items involving key-value pairs.
The Concise Data Definition Language (CDDL), standardized in RFC
8610, is often used to express CBOR data structure specifications.
It provides "control operators" as its main language extension point.
The present document defines a number of control operators that
enable the description of CBOR data structures that make use of the
newly defined tags or that employ the same underlying structures.
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/.
Bormann, et al. Expires 6 October 2021 [Page 1]
Internet-Draft Map-like data in CBOR and CDDL April 2021
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 6 October 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 . . . . . . . . . . . . . . . . . . . . . . . . 3
1.1. Terminology . . . . . . . . . . . . . . . . . . . . . . . 3
2. CBOR tags for map-like data items . . . . . . . . . . . . . . 3
2.1. Summary . . . . . . . . . . . . . . . . . . . . . . . . . 4
2.2. Key/Value Type . . . . . . . . . . . . . . . . . . . . . 5
2.3. Ordering . . . . . . . . . . . . . . . . . . . . . . . . 5
2.4. Key Uniqueness . . . . . . . . . . . . . . . . . . . . . 5
2.5. Data Item . . . . . . . . . . . . . . . . . . . . . . . . 5
2.6. Related Tags (Informative) . . . . . . . . . . . . . . . 6
2.6.1. Tag 259 . . . . . . . . . . . . . . . . . . . . . . . 6
2.6.2. Tag 275 . . . . . . . . . . . . . . . . . . . . . . . 6
2.6.3. Tag TBD279 . . . . . . . . . . . . . . . . . . . . . 6
2.6.4. Tag TDB280 . . . . . . . . . . . . . . . . . . . . . 6
3. CDDL Support for Map-Like Data Items . . . . . . . . . . . . 7
3.1. Map notation for map-like data items . . . . . . . . . . 7
3.2. Uniqueness . . . . . . . . . . . . . . . . . . . . . . . 8
4. CDDL typenames . . . . . . . . . . . . . . . . . . . . . . . 9
5. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 9
5.1. Tags . . . . . . . . . . . . . . . . . . . . . . . . . . 9
5.2. CDDL control operators . . . . . . . . . . . . . . . . . 10
6. Implementation Status . . . . . . . . . . . . . . . . . . . . 10
7. Security considerations . . . . . . . . . . . . . . . . . . . 10
8. Normative References . . . . . . . . . . . . . . . . . . . . 10
Show full document text