Concise Binary Object Representation (CBOR)
RFC 7049
| Document | Type |
RFC - Proposed Standard
(October 2013; Errata)
Was draft-bormann-cbor (individual in app area)
|
|
|---|---|---|---|
| Last updated | 2020-01-21 | ||
| Stream | IETF | ||
| Formats | plain text html pdf htmlized with errata bibtex | ||
| Reviews | |||
| Stream | WG state | (None) | |
| Document shepherd | John Levine | ||
| Shepherd write-up | Show (last changed 2013-08-27) | ||
| IESG | IESG state | RFC 7049 (Proposed Standard) | |
| Consensus Boilerplate | Yes | ||
| Telechat date | |||
| Responsible AD | Barry Leiba | ||
| Send notices to | johnl@iecc.com | ||
| IANA | IANA review state | Version Changed - Review Needed | |
| IANA action state | RFC-Ed-Ack | ||
Internet Engineering Task Force (IETF) C. Bormann
Request for Comments: 7049 Universitaet Bremen TZI
Category: Standards Track P. Hoffman
ISSN: 2070-1721 VPN Consortium
October 2013
Concise Binary Object Representation (CBOR)
Abstract
The Concise Binary Object Representation (CBOR) 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. These design goals make it different from
earlier binary serializations such as ASN.1 and MessagePack.
Status of This Memo
This is an Internet Standards Track document.
This document is a product of the Internet Engineering Task Force
(IETF). It represents the consensus of the IETF community. It has
received public review and has been approved for publication by the
Internet Engineering Steering Group (IESG). Further information on
Internet Standards is available in Section 2 of RFC 5741.
Information about the current status of this document, any errata,
and how to provide feedback on it may be obtained at
http://www.rfc-editor.org/info/rfc7049.
Copyright Notice
Copyright (c) 2013 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
(http://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.
Bormann & Hoffman Standards Track [Page 1]
RFC 7049 CBOR October 2013
Table of Contents
1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 3
1.1. Objectives . . . . . . . . . . . . . . . . . . . . . . . 4
1.2. Terminology . . . . . . . . . . . . . . . . . . . . . . . 5
2. Specification of the CBOR Encoding . . . . . . . . . . . . . 6
2.1. Major Types . . . . . . . . . . . . . . . . . . . . . . . 7
2.2. Indefinite Lengths for Some Major Types . . . . . . . . . 9
2.2.1. Indefinite-Length Arrays and Maps . . . . . . . . . . 9
2.2.2. Indefinite-Length Byte Strings and Text Strings . . . 11
2.3. Floating-Point Numbers and Values with No Content . . . . 12
2.4. Optional Tagging of Items . . . . . . . . . . . . . . . . 14
2.4.1. Date and Time . . . . . . . . . . . . . . . . . . . . 16
2.4.2. Bignums . . . . . . . . . . . . . . . . . . . . . . . 16
2.4.3. Decimal Fractions and Bigfloats . . . . . . . . . . . 17
2.4.4. Content Hints . . . . . . . . . . . . . . . . . . . . 18
2.4.4.1. Encoded CBOR Data Item . . . . . . . . . . . . . 18
2.4.4.2. Expected Later Encoding for CBOR-to-JSON
Converters . . . . . . . . . . . . . . . . . . . 18
2.4.4.3. Encoded Text . . . . . . . . . . . . . . . . . . 19
2.4.5. Self-Describe CBOR . . . . . . . . . . . . . . . . . 19
3. Creating CBOR-Based Protocols . . . . . . . . . . . . . . . . 20
3.1. CBOR in Streaming Applications . . . . . . . . . . . . . 20
3.2. Generic Encoders and Decoders . . . . . . . . . . . . . . 21
3.3. Syntax Errors . . . . . . . . . . . . . . . . . . . . . . 21
3.3.1. Incomplete CBOR Data Items . . . . . . . . . . . . . 22
3.3.2. Malformed Indefinite-Length Items . . . . . . . . . . 22
3.3.3. Unknown Additional Information Values . . . . . . . . 23
3.4. Other Decoding Errors . . . . . . . . . . . . . . . . . . 23
3.5. Handling Unknown Simple Values and Tags . . . . . . . . . 24
3.6. Numbers . . . . . . . . . . . . . . . . . . . . . . . . . 24
3.7. Specifying Keys for Maps . . . . . . . . . . . . . . . . 25
3.8. Undefined Values . . . . . . . . . . . . . . . . . . . . 26
3.9. Canonical CBOR . . . . . . . . . . . . . . . . . . . . . 26
3.10. Strict Mode . . . . . . . . . . . . . . . . . . . . . . . 28
4. Converting Data between CBOR and JSON . . . . . . . . . . . . 29
4.1. Converting from CBOR to JSON . . . . . . . . . . . . . . 29
4.2. Converting from JSON to CBOR . . . . . . . . . . . . . . 30
5. Future Evolution of CBOR . . . . . . . . . . . . . . . . . . 31
5.1. Extension Points . . . . . . . . . . . . . . . . . . . . 32
5.2. Curating the Additional Information Space . . . . . . . . 33
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