OAuth 2.0 for Browser-Based Apps
draft-ietf-oauth-browser-based-apps-04
Open Authentication Protocol A. Parecki
Internet-Draft Okta
Intended status: Best Current Practice D. Waite
Expires: March 25, 2020 Ping Identity
September 22, 2019
OAuth 2.0 for Browser-Based Apps
draft-ietf-oauth-browser-based-apps-04
Abstract
This specification details the security considerations and best
practices that must be taken into account when developing browser-
based applications that use OAuth 2.0.
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
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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 March 25, 2020.
Copyright Notice
Copyright (c) 2019 IETF Trust and the persons identified as the
document authors. All rights reserved.
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Parecki & Waite Expires March 25, 2020 [Page 1]
Internet-Draft OAuth 2.0 for Browser-Based Apps September 2019
Table of Contents
1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 2
2. Notational Conventions . . . . . . . . . . . . . . . . . . . 3
3. Terminology . . . . . . . . . . . . . . . . . . . . . . . . . 3
4. Overview . . . . . . . . . . . . . . . . . . . . . . . . . . 3
5. First-Party Applications . . . . . . . . . . . . . . . . . . 4
6. Application Architecture Patterns . . . . . . . . . . . . . . 5
6.1. Browser-Based Apps that Can Share Data with the Resource
Server . . . . . . . . . . . . . . . . . . . . . . . . . 5
6.2. JavaScript Applications with a Backend . . . . . . . . . 6
6.3. JavaScript Applications without a Backend . . . . . . . . 8
7. Authorization Code Flow . . . . . . . . . . . . . . . . . . . 9
7.1. Initiating the Authorization Request from a Browser-Based
Application . . . . . . . . . . . . . . . . . . . . . . . 9
7.2. Handling the Authorization Code Redirect . . . . . . . . 9
8. Refresh Tokens . . . . . . . . . . . . . . . . . . . . . . . 10
9. Security Considerations . . . . . . . . . . . . . . . . . . . 11
9.1. Registration of Browser-Based Apps . . . . . . . . . . . 11
9.2. Client Authentication . . . . . . . . . . . . . . . . . . 11
9.3. Client Impersonation . . . . . . . . . . . . . . . . . . 11
9.4. Cross-Site Request Forgery Protections . . . . . . . . . 12
9.5. Authorization Server Mix-Up Mitigation . . . . . . . . . 12
9.6. Cross-Domain Requests . . . . . . . . . . . . . . . . . . 12
9.7. Content-Security Policy . . . . . . . . . . . . . . . . . 13
9.8. OAuth Implicit Grant Authorization Flow . . . . . . . . . 13
9.8.1. Threat: Interception of the Redirect URI . . . . . . 13
9.8.2. Threat: Access Token Leak in Browser History . . . . 13
9.8.3. Threat: Manipulation of Scripts . . . . . . . . . . . 14
9.8.4. Threat: Access Token Leak to Third Party Scripts . . 14
9.8.5. Countermeasures . . . . . . . . . . . . . . . . . . . 14
9.8.6. Disadvantages of the Implicit Flow . . . . . . . . . 14
9.8.7. Historic Note . . . . . . . . . . . . . . . . . . . . 15
9.9. Additional Security Considerations . . . . . . . . . . . 16
10. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 16
11. References . . . . . . . . . . . . . . . . . . . . . . . . . 16
11.1. Normative References . . . . . . . . . . . . . . . . . . 16
11.2. Informative References . . . . . . . . . . . . . . . . . 17
Appendix A. Server Support Checklist . . . . . . . . . . . . . . 17
Appendix B. Document History . . . . . . . . . . . . . . . . . . 17
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