JSON Web Token Best Current Practices
RFC 8725
Document | Type |
RFC - Best Current Practice
(February 2020; No errata)
Updates RFC 7519
Also known as BCP 225
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Authors | Yaron Sheffer , Dick Hardt , Michael Jones | ||
Last updated | 2020-02-19 | ||
Replaces | draft-sheffer-oauth-jwt-bcp | ||
Stream | IETF | ||
Formats | plain text html xml pdf htmlized bibtex | ||
Reviews | |||
Stream | WG state | Submitted to IESG for Publication | |
Document shepherd | Hannes Tschofenig | ||
Shepherd write-up | Show (last changed 2018-07-17) | ||
IESG | IESG state | RFC 8725 (Best Current Practice) | |
Consensus Boilerplate | Yes | ||
Telechat date | |||
Responsible AD | Roman Danyliw | ||
Send notices to | Hannes Tschofenig <hannes.tschofenig@arm.com> | ||
IANA | IANA review state | Version Changed - Review Needed | |
IANA action state | No IANA Actions |
Internet Engineering Task Force (IETF) Y. Sheffer Request for Comments: 8725 Intuit BCP: 225 D. Hardt Updates: 7519 Category: Best Current Practice M. Jones ISSN: 2070-1721 Microsoft February 2020 JSON Web Token Best Current Practices Abstract JSON Web Tokens, also known as JWTs, are URL-safe JSON-based security tokens that contain a set of claims that can be signed and/or encrypted. JWTs are being widely used and deployed as a simple security token format in numerous protocols and applications, both in the area of digital identity and in other application areas. This Best Current Practices document updates RFC 7519 to provide actionable guidance leading to secure implementation and deployment of JWTs. Status of This Memo This memo documents an Internet Best Current Practice. 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 BCPs 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/rfc8725. 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. Table of Contents 1. Introduction 1.1. Target Audience 1.2. Conventions Used in this Document 2. Threats and Vulnerabilities 2.1. Weak Signatures and Insufficient Signature Validation 2.2. Weak Symmetric Keys 2.3. Incorrect Composition of Encryption and Signature 2.4. Plaintext Leakage through Analysis of Ciphertext Length 2.5. Insecure Use of Elliptic Curve Encryption 2.6. Multiplicity of JSON Encodings 2.7. Substitution Attacks 2.8. Cross-JWT Confusion 2.9. Indirect Attacks on the Server 3. Best Practices 3.1. Perform Algorithm Verification 3.2. Use Appropriate Algorithms 3.3. Validate All Cryptographic Operations 3.4. Validate Cryptographic Inputs 3.5. Ensure Cryptographic Keys Have Sufficient Entropy 3.6. Avoid Compression of Encryption Inputs 3.7. Use UTF-8 3.8. Validate Issuer and Subject 3.9. Use and Validate Audience 3.10. Do Not Trust Received Claims 3.11. Use Explicit Typing 3.12. Use Mutually Exclusive Validation Rules for Different Kinds of JWTs 4. Security Considerations 5. IANA Considerations 6. References 6.1. Normative References 6.2. Informative References Acknowledgements Authors' Addresses 1. Introduction JSON Web Tokens, also known as JWTs [RFC7519], are URL-safe JSON- based security tokens that contain a set of claims that can be signed and/or encrypted. The JWT specification has seen rapid adoption because it encapsulates security-relevant information in one easy-to- protect location, and because it is easy to implement using widely available tools. One application area in which JWTs are commonly used is representing digital identity information, such as OpenID Connect ID Tokens [OpenID.Core] and OAuth 2.0 [RFC6749] access tokens and refresh tokens, the details of which are deployment-specific. Since the JWT specification was published, there have been several widely published attacks on implementations and deployments. Such attacks are the result of under-specified security mechanisms, as well as incomplete implementations and incorrect usage by applications. The goal of this document is to facilitate secure implementation and deployment of JWTs. Many of the recommendations in this document are about implementation and use of the cryptographic mechanisms underlying JWTs that are defined by JSON Web Signature (JWS) [RFC7515], JSON Web Encryption (JWE) [RFC7516], and JSON Web Algorithms (JWA) [RFC7518]. Others are about use of the JWT claimsShow full document text