RFC 8392 - CBOR Web Token (CWT)

Published: May 2018
Category: Standards Track
Authors: M. Jones (Microsoft), E. Wahlstroem, S. Erdtman (Spotify AB), H. Tschofenig (ARM Ltd.)
ISSN: 2070-1721

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Abstract

CBOR Web Token (CWT) is a compact means of representing claims to be transferred between two parties. The claims in a CWT are encoded in the Concise Binary Object Representation (CBOR), and CBOR Object Signing and Encryption (COSE) is used for added application-layer security protection. A claim is a piece of information asserted about a subject and is represented as a name/value pair consisting of a claim name and a claim value. CWT is derived from JSON Web Token (JWT) but uses CBOR rather than JSON.

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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 7841.

Information about the current status of this document, any errata, and how to provide feedback on it may be obtained at https://www.rfc-editor.org/info/rfc8392.

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Copyright Notice

Copyright (c) 2018 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.

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Contents

• 1. Introduction
  • 1.1. CBOR-Related Terminology
• 2. Terminology
• 3. Claims
  • 3.1. Registered Claims
    • 3.1.1. iss (Issuer) Claim
    • 3.1.2. sub (Subject) Claim
    • 3.1.3. aud (Audience) Claim
    • 3.1.4. exp (Expiration Time) Claim
    • 3.1.5. nbf (Not Before) Claim
    • 3.1.6. iat (Issued At) Claim
    • 3.1.7. cti (CWT ID) Claim
• 4. Summary of the Claim Names, Keys, and Value Types
• 5. CBOR Tags and Claim Values
• 6. CWT CBOR Tag
• 7. Creating and Validating CWTs
  • 7.1. Creating a CWT
  • 7.2. Validating a CWT
• 8. Security Considerations
• 9. IANA Considerations
  • 9.1. CBOR Web Token (CWT) Claims Registry
    • 9.1.1. Registration Template
    • 9.1.2. Initial Registry Contents
  • 9.2. Media Type Registration
    • 9.2.1. Registry Contents
  • 9.3. CoAP Content-Formats Registration
    • 9.3.1. Registry Contents
  • 9.4. CBOR Tag registration
    • 9.4.1. Registry Contents
• 10. References
  • 10.1. Normative References
  • 10.2. Informative References
• Appendix A. Examples
  • A.1. Example CWT Claims Set
  • A.2. Example Keys
    • A.2.1. 128-Bit Symmetric Key
    • A.2.2. 256-Bit Symmetric Key
    • A.2.3. Elliptic Curve Digital Signature Algorithm (ECDSA) P-256 256-Bit COSE Key
  • A.3. Example Signed CWT
  • A.4. Example MACed CWT
  • A.5. Example Encrypted CWT
  • A.6. Example Nested CWT
  • A.7. Example MACed CWT with a Floating-Point Value
• Acknowledgements
• Authors' Addresses

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Related Resources

• Official Text: RFC 8392 (TXT)
• Official Page: RFC 8392 DataTracker
• Info: RFC Editor Info