rfc9635.original   rfc9635.txt 
GNAP J. Richer, Ed. Internet Engineering Task Force (IETF) J. Richer, Ed.
Internet-Draft Bespoke Engineering Request for Comments: 9635 Bespoke Engineering
Intended status: Standards Track F. Imbault Category: Standards Track F. Imbault
Expires: 10 September 2024 acert.io ISSN: 2070-1721 acert.io
9 March 2024 September 2024
Grant Negotiation and Authorization Protocol Grant Negotiation and Authorization Protocol (GNAP)
draft-ietf-gnap-core-protocol-19
Abstract Abstract
GNAP defines a mechanism for delegating authorization to a piece of The Grant Negotiation and Authorization Protocol (GNAP) defines a
software, and conveying the results and artifacts of that delegation mechanism for delegating authorization to a piece of software and
to the software. This delegation can include access to a set of APIs conveying the results and artifacts of that delegation to the
as well as subject information passed directly to the software. software. This delegation can include access to a set of APIs as
well as subject information passed directly to the software.
Status of This Memo Status of This Memo
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Table of Contents Table of Contents
1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 6 1. Introduction
1.1. Terminology . . . . . . . . . . . . . . . . . . . . . . . 7 1.1. Terminology
1.2. Roles . . . . . . . . . . . . . . . . . . . . . . . . . . 8 1.2. Roles
1.3. Elements . . . . . . . . . . . . . . . . . . . . . . . . 10 1.3. Elements
1.4. Trust relationships . . . . . . . . . . . . . . . . . . . 11 1.4. Trust Relationships
1.5. Protocol Flow . . . . . . . . . . . . . . . . . . . . . . 13 1.5. Protocol Flow
1.6. Sequences . . . . . . . . . . . . . . . . . . . . . . . . 16 1.6. Sequences
1.6.1. Overall Protocol Sequence . . . . . . . . . . . . . . 16 1.6.1. Overall Protocol Sequence
1.6.2. Redirect-based Interaction . . . . . . . . . . . . . 19 1.6.2. Redirect-Based Interaction
1.6.3. User-code Interaction . . . . . . . . . . . . . . . . 22 1.6.3. User Code Interaction
1.6.4. Asynchronous Authorization . . . . . . . . . . . . . 25 1.6.4. Asynchronous Authorization
1.6.5. Software-only Authorization . . . . . . . . . . . . . 27 1.6.5. Software-Only Authorization
1.6.6. Refreshing an Expired Access Token . . . . . . . . . 28 1.6.6. Refreshing an Expired Access Token
1.6.7. Requesting Subject Information Only . . . . . . . . . 30 1.6.7. Requesting Subject Information Only
1.6.8. Cross-User Authentication . . . . . . . . . . . . . . 31 1.6.8. Cross-User Authentication
2. Requesting Access . . . . . . . . . . . . . . . . . . . . . . 34 2. Requesting Access
2.1. Requesting Access to Resources . . . . . . . . . . . . . 36 2.1. Requesting Access to Resources
2.1.1. Requesting a Single Access Token . . . . . . . . . . 36 2.1.1. Requesting a Single Access Token
2.1.2. Requesting Multiple Access Tokens . . . . . . . . . . 39 2.1.2. Requesting Multiple Access Tokens
2.2. Requesting Subject Information . . . . . . . . . . . . . 41 2.2. Requesting Subject Information
2.3. Identifying the Client Instance . . . . . . . . . . . . . 42 2.3. Identifying the Client Instance
2.3.1. Identifying the Client Instance by Reference . . . . 44 2.3.1. Identifying the Client Instance by Reference
2.3.2. Providing Displayable Client Instance Information . . 45 2.3.2. Providing Displayable Client Instance Information
2.3.3. Authenticating the Client Instance . . . . . . . . . 45 2.3.3. Authenticating the Client Instance
2.4. Identifying the User . . . . . . . . . . . . . . . . . . 46 2.4. Identifying the User
2.4.1. Identifying the User by Reference . . . . . . . . . . 47 2.4.1. Identifying the User by Reference
2.5. Interacting with the User . . . . . . . . . . . . . . . . 48 2.5. Interacting with the User
2.5.1. Start Mode Definitions . . . . . . . . . . . . . . . 50 2.5.1. Start Mode Definitions
2.5.2. Interaction Finish Methods . . . . . . . . . . . . . 52 2.5.2. Interaction Finish Methods
2.5.3. Hints . . . . . . . . . . . . . . . . . . . . . . . . 55 2.5.3. Hints
3. Grant Response . . . . . . . . . . . . . . . . . . . . . . . 56 3. Grant Response
3.1. Request Continuation . . . . . . . . . . . . . . . . . . 58 3.1. Request Continuation
3.2. Access Tokens . . . . . . . . . . . . . . . . . . . . . . 59 3.2. Access Tokens
3.2.1. Single Access Token . . . . . . . . . . . . . . . . . 59 3.2.1. Single Access Token
3.2.2. Multiple Access Tokens . . . . . . . . . . . . . . . 63 3.2.2. Multiple Access Tokens
3.3. Interaction Modes . . . . . . . . . . . . . . . . . . . . 64 3.3. Interaction Modes
3.3.1. Redirection to an arbitrary URI . . . . . . . . . . . 66 3.3.1. Redirection to an Arbitrary URI
3.3.2. Launch of an application URI . . . . . . . . . . . . 66 3.3.2. Launch of an Application URI
3.3.3. Display of a Short User Code . . . . . . . . . . . . 67 3.3.3. Display of a Short User Code
3.3.4. Display of a Short User Code and URI . . . . . . . . 68 3.3.4. Display of a Short User Code and URI
3.3.5. Interaction Finish . . . . . . . . . . . . . . . . . 69 3.3.5. Interaction Finish
3.4. Returning Subject Information . . . . . . . . . . . . . . 69 3.4. Returning Subject Information
3.4.1. Assertion Formats . . . . . . . . . . . . . . . . . . 71 3.4.1. Assertion Formats
3.5. Returning a Dynamically-bound Client Instance 3.5. Returning a Dynamically Bound Client Instance Identifier
Identifier . . . . . . . . . . . . . . . . . . . . . . . 72 3.6. Error Response
3.6. Error Response . . . . . . . . . . . . . . . . . . . . . 72 4. Determining Authorization and Consent
4.1. Starting Interaction with the End User
4. Determining Authorization and Consent . . . . . . . . . . . . 74 4.1.1. Interaction at a Redirected URI
4.1. Starting Interaction With the End User . . . . . . . . . 79 4.1.2. Interaction at the Static User Code URI
4.1.1. Interaction at a Redirected URI . . . . . . . . . . . 79 4.1.3. Interaction at a Dynamic User Code URI
4.1.2. Interaction at the Static User Code URI . . . . . . . 80 4.1.4. Interaction through an Application URI
4.1.3. Interaction at a Dynamic User Code URI . . . . . . . 81 4.2. Post-Interaction Completion
4.1.4. Interaction through an Application URI . . . . . . . 83
4.2. Post-Interaction Completion . . . . . . . . . . . . . . . 83
4.2.1. Completing Interaction with a Browser Redirect to the 4.2.1. Completing Interaction with a Browser Redirect to the
Callback URI . . . . . . . . . . . . . . . . . . . . 84 Callback URI
4.2.2. Completing Interaction with a Direct HTTP Request 4.2.2. Completing Interaction with a Direct HTTP Request
Callback . . . . . . . . . . . . . . . . . . . . . . 85 Callback
4.2.3. Calculating the interaction hash . . . . . . . . . . 86 4.2.3. Calculating the Interaction Hash
5. Continuing a Grant Request . . . . . . . . . . . . . . . . . 87 5. Continuing a Grant Request
5.1. Continuing After a Completed Interaction . . . . . . . . 90 5.1. Continuing after a Completed Interaction
5.2. Continuing During Pending Interaction (Polling) . . . . . 92 5.2. Continuing during Pending Interaction (Polling)
5.3. Modifying an Existing Request . . . . . . . . . . . . . . 94 5.3. Modifying an Existing Request
5.4. Revoking a Grant Request . . . . . . . . . . . . . . . . 100 5.4. Revoking a Grant Request
6. Token Management . . . . . . . . . . . . . . . . . . . . . . 101 6. Token Management
6.1. Rotating the Access Token Value . . . . . . . . . . . . . 102 6.1. Rotating the Access Token Value
6.1.1. Binding a New Key to the Rotated Access Token . . . . 104 6.1.1. Binding a New Key to the Rotated Access Token
6.2. Revoking the Access Token . . . . . . . . . . . . . . . . 105 6.2. Revoking the Access Token
7. Securing Requests from the Client Instance . . . . . . . . . 106 7. Securing Requests from the Client Instance
7.1. Key Formats . . . . . . . . . . . . . . . . . . . . . . . 107 7.1. Key Formats
7.1.1. Key References . . . . . . . . . . . . . . . . . . . 108 7.1.1. Key References
7.1.2. Key Protection . . . . . . . . . . . . . . . . . . . 109 7.1.2. Key Protection
7.2. Presenting Access Tokens . . . . . . . . . . . . . . . . 109 7.2. Presenting Access Tokens
7.3. Proving Possession of a Key with a Request . . . . . . . 110 7.3. Proving Possession of a Key with a Request
7.3.1. HTTP Message Signatures . . . . . . . . . . . . . . . 114 7.3.1. HTTP Message Signatures
7.3.2. Mutual TLS . . . . . . . . . . . . . . . . . . . . . 121 7.3.2. Mutual TLS
7.3.3. Detached JWS . . . . . . . . . . . . . . . . . . . . 124 7.3.3. Detached JWS
7.3.4. Attached JWS . . . . . . . . . . . . . . . . . . . . 128 7.3.4. Attached JWS
8. Resource Access Rights . . . . . . . . . . . . . . . . . . . 133 8. Resource Access Rights
8.1. Requesting Resources By Reference . . . . . . . . . . . . 137 8.1. Requesting Resources by Reference
9. Discovery . . . . . . . . . . . . . . . . . . . . . . . . . . 140 9. Discovery
9.1. RS-first Method of AS Discovery . . . . . . . . . . . . . 141 9.1. RS-First Method of AS Discovery
9.2. Dynamic grant endpoint discovery . . . . . . . . . . . . 143 9.2. Dynamic Grant Endpoint Discovery
10. Acknowledgements . . . . . . . . . . . . . . . . . . . . . . 144 10. IANA Considerations
11. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 144 10.1. HTTP Authentication Scheme Registration
11.1. HTTP Authentication Scheme Registration . . . . . . . . 145 10.2. Media Type Registration
11.2. Media Type Registration . . . . . . . . . . . . . . . . 145 10.2.1. application/gnap-binding-jwsd
11.3. GNAP Grant Request Parameters . . . . . . . . . . . . . 149 10.2.2. application/gnap-binding-jws
11.3.1. Registration Template . . . . . . . . . . . . . . . 149 10.2.3. application/gnap-binding-rotation-jwsd
11.3.2. Initial Contents . . . . . . . . . . . . . . . . . . 149 10.2.4. application/gnap-binding-rotation-jws
11.4. GNAP Access Token Flags . . . . . . . . . . . . . . . . 150 10.3. GNAP Grant Request Parameters
11.4.1. Registration Template . . . . . . . . . . . . . . . 150 10.3.1. Registration Template
11.4.2. Initial Contents . . . . . . . . . . . . . . . . . . 151 10.3.2. Initial Contents
11.5. GNAP Subject Information Request Fields . . . . . . . . 151 10.4. GNAP Access Token Flags
11.5.1. Registration Template . . . . . . . . . . . . . . . 151 10.4.1. Registration Template
11.5.2. Initial Contents . . . . . . . . . . . . . . . . . . 152 10.4.2. Initial Contents
11.6. GNAP Assertion Formats . . . . . . . . . . . . . . . . . 152 10.5. GNAP Subject Information Request Fields
11.6.1. Registration Template . . . . . . . . . . . . . . . 152 10.5.1. Registration Template
11.6.2. Initial Contents . . . . . . . . . . . . . . . . . . 152 10.5.2. Initial Contents
11.7. GNAP Client Instance Fields . . . . . . . . . . . . . . 153 10.6. GNAP Assertion Formats
11.7.1. Registration Template . . . . . . . . . . . . . . . 153 10.6.1. Registration Template
11.7.2. Initial Contents . . . . . . . . . . . . . . . . . . 153 10.6.2. Initial Contents
11.8. GNAP Client Instance Display Fields . . . . . . . . . . 154 10.7. GNAP Client Instance Fields
11.8.1. Registration Template . . . . . . . . . . . . . . . 154 10.7.1. Registration Template
11.8.2. Initial Contents . . . . . . . . . . . . . . . . . . 154 10.7.2. Initial Contents
11.9. GNAP Interaction Start Modes . . . . . . . . . . . . . . 155 10.8. GNAP Client Instance Display Fields
11.9.1. Registration Template . . . . . . . . . . . . . . . 155 10.8.1. Registration Template
11.9.2. Initial Contents . . . . . . . . . . . . . . . . . . 156 10.8.2. Initial Contents
11.10. GNAP Interaction Finish Methods . . . . . . . . . . . . 156 10.9. GNAP Interaction Start Modes
11.10.1. Registration Template . . . . . . . . . . . . . . . 156 10.9.1. Registration Template
11.10.2. Initial Contents . . . . . . . . . . . . . . . . . 157 10.9.2. Initial Contents
11.11. GNAP Interaction Hints . . . . . . . . . . . . . . . . . 157 10.10. GNAP Interaction Finish Methods
11.11.1. Registration Template . . . . . . . . . . . . . . . 157 10.10.1. Registration Template
11.11.2. Initial Contents . . . . . . . . . . . . . . . . . 157 10.10.2. Initial Contents
11.12. GNAP Grant Response Parameters . . . . . . . . . . . . . 158 10.11. GNAP Interaction Hints
11.12.1. Registration Template . . . . . . . . . . . . . . . 158 10.11.1. Registration Template
11.12.2. Initial Contents . . . . . . . . . . . . . . . . . 158 10.11.2. Initial Contents
11.13. GNAP Interaction Mode Responses . . . . . . . . . . . . 159 10.12. GNAP Grant Response Parameters
11.13.1. Registration Template . . . . . . . . . . . . . . . 159 10.12.1. Registration Template
11.13.2. Initial Contents . . . . . . . . . . . . . . . . . 159 10.12.2. Initial Contents
11.14. GNAP Subject Information Response Fields . . . . . . . . 160 10.13. GNAP Interaction Mode Responses
11.14.1. Registration Template . . . . . . . . . . . . . . . 160 10.13.1. Registration Template
11.14.2. Initial Contents . . . . . . . . . . . . . . . . . 160 10.13.2. Initial Contents
11.15. GNAP Error Codes . . . . . . . . . . . . . . . . . . . . 161 10.14. GNAP Subject Information Response Fields
11.15.1. Registration Template . . . . . . . . . . . . . . . 161 10.14.1. Registration Template
11.15.2. Initial Contents . . . . . . . . . . . . . . . . . 161 10.14.2. Initial Contents
11.16. GNAP Key Proofing Methods . . . . . . . . . . . . . . . 162 10.15. GNAP Error Codes
11.16.1. Registration Template . . . . . . . . . . . . . . . 162 10.15.1. Registration Template
11.16.2. Initial Contents . . . . . . . . . . . . . . . . . 163 10.15.2. Initial Contents
11.17. GNAP Key Formats . . . . . . . . . . . . . . . . . . . . 163 10.16. GNAP Key Proofing Methods
11.17.1. Registration Template . . . . . . . . . . . . . . . 163 10.16.1. Registration Template
11.17.2. Initial Contents . . . . . . . . . . . . . . . . . 164 10.16.2. Initial Contents
11.18. GNAP Authorization Server Discovery Fields . . . . . . . 164 10.17. GNAP Key Formats
11.18.1. Registration Template . . . . . . . . . . . . . . . 164 10.17.1. Registration Template
11.18.2. Initial Contents . . . . . . . . . . . . . . . . . 165 10.17.2. Initial Contents
12. Implementation Status . . . . . . . . . . . . . . . . . . . . 165 10.18. GNAP Authorization Server Discovery Fields
13. Security Considerations . . . . . . . . . . . . . . . . . . . 166 10.18.1. Registration Template
13.1. TLS Protection in Transit . . . . . . . . . . . . . . . 166 10.18.2. Initial Contents
13.2. Signing Requests from the Client Software . . . . . . . 167 11. Security Considerations
13.3. MTLS Message Integrity . . . . . . . . . . . . . . . . . 169 11.1. TLS Protection in Transit
13.4. MTLS Deployment Patterns . . . . . . . . . . . . . . . . 169 11.2. Signing Requests from the Client Software
13.5. Protection of Client Instance Key Material . . . . . . . 170 11.3. MTLS Message Integrity
13.6. Protection of Authorization Server . . . . . . . . . . . 171 11.4. MTLS Deployment Patterns
13.7. Symmetric and Asymmetric Client Instance Keys . . . . . 172 11.5. Protection of Client Instance Key Material
13.8. Generation of Access Tokens . . . . . . . . . . . . . . 173 11.6. Protection of Authorization Server
13.9. Bearer Access Tokens . . . . . . . . . . . . . . . . . . 174 11.7. Symmetric and Asymmetric Client Instance Keys
13.10. Key-Bound Access Tokens . . . . . . . . . . . . . . . . 175 11.8. Generation of Access Tokens
13.11. Exposure of End-user Credentials to Client Instance . . 176 11.9. Bearer Access Tokens
13.12. Mixing Up Authorization Servers . . . . . . . . . . . . 177 11.10. Key-Bound Access Tokens
13.13. Processing of Client-Presented User Information . . . . 177 11.11. Exposure of End-User Credentials to Client Instance
13.14. Client Instance Pre-registration . . . . . . . . . . . . 178 11.12. Mixing Up Authorization Servers
13.15. Client Instance Impersonation . . . . . . . . . . . . . 180 11.13. Processing of Client-Presented User Information
13.16. Client-Hosted Logo URI . . . . . . . . . . . . . . . . . 180 11.14. Client Instance Pre-registration
13.17. Interception of Information in the Browser . . . . . . . 181 11.15. Client Instance Impersonation
13.18. Callback URI Manipulation . . . . . . . . . . . . . . . 181 11.16. Client-Hosted Logo URI
13.19. Redirection Status Codes . . . . . . . . . . . . . . . . 182 11.17. Interception of Information in the Browser
13.20. Interception of Responses from the AS . . . . . . . . . 183 11.18. Callback URI Manipulation
13.21. Key Distribution . . . . . . . . . . . . . . . . . . . . 183 11.19. Redirection Status Codes
13.22. Key Rotation Policy . . . . . . . . . . . . . . . . . . 184 11.20. Interception of Responses from the AS
13.23. Interaction Finish Modes and Polling . . . . . . . . . . 185 11.21. Key Distribution
13.24. Session Management for Interaction Finish Methods . . . 185 11.22. Key Rotation Policy
13.25. Calculating Interaction Hash . . . . . . . . . . . . . . 187 11.23. Interaction Finish Modes and Polling
13.26. Storage of Information During Interaction and 11.24. Session Management for Interaction Finish Methods
Continuation . . . . . . . . . . . . . . . . . . . . . 189 11.25. Calculating Interaction Hash
13.27. Denial of Service (DoS) through Grant Continuation . . . 190 11.26. Storage of Information during Interaction and Continuation
13.28. Exhaustion of Random Value Space . . . . . . . . . . . . 191 11.27. Denial of Service (DoS) through Grant Continuation
13.29. Front-channel URIs . . . . . . . . . . . . . . . . . . . 191 11.28. Exhaustion of Random Value Space
13.30. Processing Assertions . . . . . . . . . . . . . . . . . 192 11.29. Front-Channel URIs
13.31. Stolen Token Replay . . . . . . . . . . . . . . . . . . 193 11.30. Processing Assertions
13.32. Self-contained Stateless Access Tokens . . . . . . . . . 194 11.31. Stolen Token Replay
13.33. Network Problems and Token and Grant Management . . . . 195 11.32. Self-Contained Stateless Access Tokens
13.34. Server-side Request Forgery (SSRF) . . . . . . . . . . . 196 11.33. Network Problems and Token and Grant Management
13.35. Multiple Key Formats . . . . . . . . . . . . . . . . . . 197 11.34. Server-Side Request Forgery (SSRF)
13.36. Asynchronous Interactions . . . . . . . . . . . . . . . 198 11.35. Multiple Key Formats
13.37. Compromised RS . . . . . . . . . . . . . . . . . . . . . 199 11.36. Asynchronous Interactions
13.38. AS-Provided Token Keys . . . . . . . . . . . . . . . . . 199 11.37. Compromised RS
14. Privacy Considerations . . . . . . . . . . . . . . . . . . . 200 11.38. AS-Provided Token Keys
14.1. Surveillance . . . . . . . . . . . . . . . . . . . . . . 200 12. Privacy Considerations
14.1.1. Surveillance by the Client . . . . . . . . . . . . . 200 12.1. Surveillance
14.1.2. Surveillance by the Authorization Server . . . . . . 201 12.1.1. Surveillance by the Client
14.2. Stored Data . . . . . . . . . . . . . . . . . . . . . . 201 12.1.2. Surveillance by the Authorization Server
14.3. Intrusion . . . . . . . . . . . . . . . . . . . . . . . 202 12.2. Stored Data
14.4. Correlation . . . . . . . . . . . . . . . . . . . . . . 202 12.3. Intrusion
14.4.1. Correlation by Clients . . . . . . . . . . . . . . . 202 12.4. Correlation
14.4.2. Correlation by Resource Servers . . . . . . . . . . 203 12.4.1. Correlation by Clients
14.4.3. Correlation by Authorization Servers . . . . . . . . 204 12.4.2. Correlation by Resource Servers
14.5. Disclosure in Shared References . . . . . . . . . . . . 204 12.4.3. Correlation by Authorization Servers
15. References . . . . . . . . . . . . . . . . . . . . . . . . . 204 12.5. Disclosure in Shared References
15.1. Normative References . . . . . . . . . . . . . . . . . . 204 13. References
15.2. Informative References . . . . . . . . . . . . . . . . . 206 13.1. Normative References
Appendix A. Document History . . . . . . . . . . . . . . . . . . 209 13.2. Informative References
Appendix B. Compared to OAuth 2.0 . . . . . . . . . . . . . . . 215 Appendix A. Comparison with OAuth 2.0
Appendix C. Example Protocol Flows . . . . . . . . . . . . . . . 217 Appendix B. Example Protocol Flows
C.1. Redirect-Based User Interaction . . . . . . . . . . . . . 218 B.1. Redirect-Based User Interaction
C.2. Secondary Device Interaction . . . . . . . . . . . . . . 221 B.2. Secondary Device Interaction
C.3. No User Involvement . . . . . . . . . . . . . . . . . . . 224 B.3. No User Involvement
C.4. Asynchronous Authorization . . . . . . . . . . . . . . . 225 B.4. Asynchronous Authorization
C.5. Applying OAuth 2.0 Scopes and Client IDs . . . . . . . . 229 B.5. Applying OAuth 2.0 Scopes and Client IDs
Appendix D. Interoperability Profiles . . . . . . . . . . . . . 230 Appendix C. Interoperability Profiles
D.1. Web-based Redirection . . . . . . . . . . . . . . . . . . 231 C.1. Web-Based Redirection
D.2. Secondary Device . . . . . . . . . . . . . . . . . . . . 231 C.2. Secondary Device
Appendix E. Guidance for Extensions . . . . . . . . . . . . . . 232 Appendix D. Guidance for Extensions
Appendix F. JSON Structures and Polymorphism . . . . . . . . . . 233 Appendix E. JSON Structures and Polymorphism
Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 234 Acknowledgements
Authors' Addresses
1. Introduction 1. Introduction
This protocol allows a piece of software, the client instance, to GNAP allows a piece of software, the client instance, to request
request delegated authorization to resource servers and subject delegated authorization to resource servers and subject information.
information. The delegated access to the resource server can be used The delegated access to the resource server can be used by the client
by the client instance to access resources and APIs on behalf a instance to access resources and APIs on behalf a resource owner, and
resource owner, and delegated access to subject information can in delegated access to subject information can in turn be used by the
turn be used by the client instance to make authentication decisions. client instance to make authentication decisions. This delegation is
This delegation is facilitated by an authorization server usually on facilitated by an authorization server, usually on behalf of a
behalf of a resource owner. The end user operating the software can resource owner. The end user operating the software can interact
interact with the authorization server to authenticate, provide with the authorization server to authenticate, provide consent, and
consent, and authorize the request as a resource owner. authorize the request as a resource owner.
The process by which the delegation happens is known as a grant, and The process by which the delegation happens is known as a grant, and
GNAP allows for the negotiation of the grant process over time by GNAP allows for the negotiation of the grant process over time by
multiple parties acting in distinct roles. multiple parties acting in distinct roles.
This specification focuses on the portions of the delegation process This specification focuses on the portions of the delegation process
facing the client instance. In particular, this specification facing the client instance. In particular, this specification
defines interoperable methods for a client instance to request, defines interoperable methods for a client instance to request,
negotiate, and receive access to information facilitated by the negotiate, and receive access to information facilitated by the
authorization server. This specification additionally defines authorization server. This specification additionally defines
methods for the client instance to access protected resources at a methods for the client instance to access protected resources at a
resource server. This specification also discusses discovery resource server. This specification also discusses discovery
mechanisms for the client instance to configure itself dynamically. mechanisms for the client instance to configure itself dynamically.
The means for an authorization server and resource server to The means for an authorization server and resource server to
interoperate are discussed in the companion document, interoperate are discussed in the companion document [GNAP-RS].
[I-D.ietf-gnap-resource-servers].
The focus of this protocol is to provide interoperability between the The focus of this protocol is to provide interoperability between the
different parties acting in each role, and is not to specify different parties acting in each role, not to specify implementation
implementation details of each. Where appropriate, GNAP may make details of each. Where appropriate, GNAP may make recommendations
recommendations about internal implementation details, but these about internal implementation details, but these recommendations are
recommendations are to ensure the security of the overall deployment to ensure the security of the overall deployment rather than to be
rather than to be prescriptive in the implementation. prescriptive in the implementation.
This protocol solves many of the same use cases as OAuth 2.0 This protocol solves many of the same use cases as OAuth 2.0
[RFC6749], OpenID Connect [OIDC], and the family of protocols that [RFC6749], OpenID Connect [OIDC], and the family of protocols that
have grown up around that ecosystem. However, GNAP is not an have grown up around that ecosystem. However, GNAP is not an
extension of OAuth 2.0 and is not intended to be directly compatible extension of OAuth 2.0 and is not intended to be directly compatible
with OAuth 2.0. GNAP seeks to provide functionality and solve use with OAuth 2.0. GNAP seeks to provide functionality and solve use
cases that OAuth 2.0 cannot easily or cleanly address. Appendix B cases that OAuth 2.0 cannot easily or cleanly address. Appendix A
further details the protocol rationale compared to OAuth 2.0. GNAP further details the protocol rationale compared to OAuth 2.0. GNAP
and OAuth 2.0 will likely exist in parallel for many deployments, and and OAuth 2.0 will likely exist in parallel for many deployments, and
considerations have been taken to facilitate the mapping and considerations have been taken to facilitate the mapping and
transition from existing OAuth 2.0 systems to GNAP. Some examples of transition from existing OAuth 2.0 systems to GNAP. Some examples of
these can be found in Appendix C.5. these can be found in Appendix B.5.
1.1. Terminology 1.1. Terminology
The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT", The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT",
"SHOULD", "SHOULD NOT", "RECOMMENDED", "NOT RECOMMENDED", "MAY", and "SHOULD", "SHOULD NOT", "RECOMMENDED", "NOT RECOMMENDED", "MAY", and
"OPTIONAL" in this document are to be interpreted as described in "OPTIONAL" in this document are to be interpreted as described in
BCP 14 [RFC2119] [RFC8174] when, and only when, they appear in all BCP 14 [RFC2119] [RFC8174] when, and only when, they appear in all
capitals, as shown here. capitals, as shown here.
This document contains non-normative examples of partial and complete This document contains non-normative examples of partial and complete
HTTP messages, JSON structures, URIs, query components, keys, and HTTP messages, JSON structures, URIs, query components, keys, and
other elements. Whenever possible, the document uses URI as a other elements. Whenever possible, the document uses URI as a
generic term, since it aligns with [RFC3986] recommendations and generic term, since it aligns with the recommendations in [RFC3986]
matches better with the intent that the identifier may be reachable and better matches the intent that the identifier may be reachable
through various/generic means (compared to URLs). Some examples use through various/generic means (compared to URLs). Some examples use
a single trailing backslash \ to indicate line wrapping for long a single trailing backslash (\) to indicate line wrapping for long
values, as per [RFC8792]. The \ character and leading spaces on values, as per [RFC8792]. The \ character and leading spaces on
wrapped lines are not part of the value. wrapped lines are not part of the value.
This document uses the term "mutual TLS" as defined by [RFC8705]. This document uses the term "mutual TLS" as defined by [RFC8705].
The shortened form "MTLS" is used to mean the same thing. The shortened form "MTLS" is used to mean the same thing.
For brevity, the term "signature" on its own is used in this document For brevity, the term "signature" on its own is used in this document
to refer to both digital signatures (which use asymmetric to refer to both digital signatures (which use asymmetric
cryptography) and keyed MACs (which use symmetric cryptography). cryptography) and keyed MACs (which use symmetric cryptography).
Similarly, the verb "sign" refers to the generation of either a Similarly, the verb "sign" refers to the generation of either a
digital signature or keyed MAC over a given signature base. The digital signature or a keyed MAC over a given signature base. The
qualified term "digital signature" refers specifically to the output qualified term "digital signature" refers specifically to the output
of an asymmetric cryptographic signing operation. of an asymmetric cryptographic signing operation.
1.2. Roles 1.2. Roles
The parties in GNAP perform actions under different roles. Roles are The parties in GNAP perform actions under different roles. Roles are
defined by the actions taken and the expectations leveraged on the defined by the actions taken and the expectations leveraged on the
role by the overall protocol. role by the overall protocol.
+-------------+ +------------+ +-------------+ +------------+
skipping to change at page 8, line 30 skipping to change at line 354
â•‘ | Instance | â•‘ | Instance |
â•‘ +----+-----+ â•‘ +----+-----+
â•‘ â•‘ â•‘ â•‘
.----+----. â•‘ .----------. .----+----. â•‘ .----------.
| | +=====+ | | | +=====+ |
| Resource | | End | | Resource | | End |
| Owner | ~ ~ ~ ~ ~ ~ | User | | Owner | ~ ~ ~ ~ ~ ~ | User |
| | | | | | | |
`---------` `----------` `---------` `----------`
Legend Legend:
===== indicates interaction between a human and computer ===== indicates interaction between a human and computer
----- indicates interaction between two pieces of software ----- indicates interaction between two pieces of software
~ ~ ~ indicates a potential equivalence or out-of-band ~ ~ ~ indicates a potential equivalence or out-of-band
communication between roles communication between roles
Figure 1: Figure 1: Roles in GNAP Figure 1: Roles in GNAP
Authorization Server (AS): server that grants delegated privileges Authorization Server (AS): Server that grants delegated privileges
to a particular instance of client software in the form of access to a particular instance of client software in the form of access
tokens or other information (such as subject information). The AS tokens or other information (such as subject information). The AS
is uniquely defined by the _grant endpoint URI_, which is the is uniquely defined by the _grant endpoint URI_, which is the
absolute URI where grant requests are started by clients. absolute URI where grant requests are started by clients.
Client: application that consumes resources from one or several RSs, Client: Application that consumes resources from one or several
possibly requiring access privileges from one or several ASs. The resource servers, possibly requiring access privileges from one or
client is operated by the end user or it runs autonomously on several ASes. The client is operated by the end user, or it runs
behalf of a resource owner. autonomously on behalf of a resource owner.
Example: a client can be a mobile application, a web application, For example, a client can be a mobile application, a web
a back-end data processor, etc. application, a back-end data processor, etc.
Note: this specification differentiates between a specific Note: This specification differentiates between a specific
instance (the client instance, identified by its unique key) and instance (the client instance, identified by its unique key) and
the software running the instance (the client software). For some the software running the instance (the client software). For some
kinds of client software, there could be many instances of that kinds of client software, there could be many instances of that
software, each instance with a different key. software, each instance with a different key.
Resource Server (RS): server that provides an API on protected Resource Server (RS): Server that provides an API on protected
resources, where operations on the API require a valid access resources, where operations on the API require a valid access
token issued by a trusted AS. token issued by a trusted AS.
Resource Owner (RO): subject entity that may grant or deny Resource Owner (RO): Subject entity that may grant or deny
operations on resources it has authority upon. operations on resources it has authority upon.
Note: the act of granting or denying an operation may be manual Note: The act of granting or denying an operation may be manual
(i.e. through an interaction with a physical person) or automatic (i.e., through an interaction with a physical person) or automatic
(i.e. through predefined organizational rules). (i.e., through predefined organizational rules).
End user: natural person that operates a client instance. End user: Natural person that operates a client instance.
Note: that natural person may or may not be the same entity as the Note: That natural person may or may not be the same entity as the
RO. RO.
The design of GNAP does not assume any one deployment architecture, The design of GNAP does not assume any one deployment architecture
but instead attempts to define roles that can be fulfilled in a but instead attempts to define roles that can be fulfilled in a
number of different ways for different use cases. As long as a given number of different ways for different use cases. As long as a given
role fulfills all of its obligations and behaviors as defined by the role fulfills all of its obligations and behaviors as defined by the
protocol, GNAP does not make additional requirements on its structure protocol, GNAP does not make additional requirements on its structure
or setup. or setup.
Multiple roles can be fulfilled by the same party, and a given party Multiple roles can be fulfilled by the same party, and a given party
can switch roles in different instances of the protocol. For can switch roles in different instances of the protocol. For
example, the RO and end user in many instances are the same person, example, in many instances, the RO and end user are the same person,
where a user is authorizing the client instance to act on their own where a user authorizes the client instance to act on their own
behalf at the RS. In this case, one party fulfills both of the RO behalf at the RS. In this case, one party fulfills the roles of both
and end-user roles, but the roles themselves are still defined RO and end user, but the roles themselves are still defined
separately from each other to allow for other use cases where they separately from each other to allow for other use cases where they
are fulfilled by different parties. are fulfilled by different parties.
For another example, in some complex scenarios, an RS receiving As another example, in some complex scenarios, an RS receiving
requests from one client instance can act as a client instance for a requests from one client instance can act as a client instance for a
downstream secondary RS in order to fulfill the original request. In downstream secondary RS in order to fulfill the original request. In
this case, one piece of software is both an RS and a client instance this case, one piece of software is both an RS and a client instance
from different perspectives, and it fulfills these roles separately from different perspectives, and it fulfills these roles separately
as far as the overall protocol is concerned. as far as the overall protocol is concerned.
A single role need not be deployed as a monolithic service. For A single role need not be deployed as a monolithic service. For
example, a client instance could have front-end components that are example, a client instance could have front-end components that are
installed on the end user's device as well as a back-end system that installed on the end user's device as well as a back-end system that
the front-end communicates with. If both of these components the front-end communicates with. If both of these components
participate in the delegation protocol, they are both considered part participate in the delegation protocol, they are both considered part
of the client instance. If there are several copies of the client of the client instance. If there are several copies of the client
software that run separately but all share the same key material, software that run separately but all share the same key material,
such as a deployed cluster, then this cluster is considered a single such as a deployed cluster, then this cluster is considered a single
client instance. In these cases, the distinct components of what is client instance. In these cases, the distinct components of what is
considered a GNAP client instance may use any number of different considered a GNAP client instance may use any number of different
communication mechanisms between them, all of which would be communication mechanisms between them, all of which would be
considered an implementation detail of the client instances and out considered an implementation detail of the client instances and out
of scope of GNAP. of scope of GNAP.
For another example, an AS could likewise be built out of many As another example, an AS could likewise be built out of many
constituent components in a distributed architecture. The component constituent components in a distributed architecture. The component
that the client instance calls directly could be different from the that the client instance calls directly could be different from the
component that the RO interacts with to drive consent, since API component that the RO interacts with to drive consent, since API
calls and user interaction have different security considerations in calls and user interaction have different security considerations in
many environments. Furthermore, the AS could need to collect many environments. Furthermore, the AS could need to collect
identity claims about the RO from one system that deals with user identity claims about the RO from one system that deals with user
attributes while generating access tokens at another system that attributes while generating access tokens at another system that
deals with security rights. From the perspective of GNAP, all of deals with security rights. From the perspective of GNAP, all of
these are pieces of the AS and together fulfill the role of the AS as these are pieces of the AS and together fulfill the role of the AS as
defined by the protocol. These pieces may have their own internal defined by the protocol. These pieces may have their own internal
communications mechanisms which are considered out of scope of GNAP. communications mechanisms, which are considered out of scope of GNAP.
1.3. Elements 1.3. Elements
In addition to the roles above, the protocol also involves several In addition to the roles above, the protocol also involves several
elements that are acted upon by the roles throughout the process. elements that are acted upon by the roles throughout the process.
Access Token: a data artifact representing a set of rights and/or Access Token: A data artifact representing a set of rights and/or
attributes. attributes.
Note: an access token can be first issued to a client instance Note: An access token can be first issued to a client instance
(requiring authorization by the RO) and subsequently rotated. (requiring authorization by the RO) and subsequently rotated.
Grant: (verb): to permit an instance of client software to receive Grant: (verb): To permit an instance of client software to receive
some attributes at a specific time and valid for a specific some attributes at a specific time and valid for a specific
duration and/or to exercise some set of delegated rights to access duration and/or to exercise some set of delegated rights to access
a protected resource; a protected resource.
(noun): the act of granting permission to a client instance. (noun): The act of granting permission to a client instance.
Privilege: right or attribute associated with a subject. Privilege: Right or attribute associated with a subject.
Note: the RO defines and maintains the rights and attributes Note: The RO defines and maintains the rights and attributes
associated to the protected resource, and might temporarily associated to the protected resource and might temporarily
delegate some set of those privileges to an end user. This delegate some set of those privileges to an end user. This
process is refered to as privilege delegation. process is referred to as "privilege delegation".
Protected Resource: protected API (Application Programming Protected Resource: Protected API that is served by an RS and that
Interface) served by an RS and that can be accessed by a client, can be accessed by a client, if and only if a valid and sufficient
if and only if a valid and sufficient access token is provided. access token is provided.
Note: to avoid complex sentences, the specification document may Note: To avoid complex sentences, the specification document may
simply refer to "resource" instead of "protected resource". simply refer to "resource" instead of "protected resource".
Right: ability given to a subject to perform a given operation on a Right: Ability given to a subject to perform a given operation on a
resource under the control of an RS. resource under the control of an RS.
Subject: person or organization. The subject decides whether and Subject: Person or organization. The subject decides whether and
under which conditions its attributes can be disclosed to other under which conditions its attributes can be disclosed to other
parties. parties.
Subject Information: set of statements and attributes asserted by an Subject Information: Set of statements and attributes asserted by an
AS about a subject. These statements can be used by the client AS about a subject. These statements can be used by the client
instance as part of an authentication decision. instance as part of an authentication decision.
1.4. Trust relationships 1.4. Trust Relationships
GNAP defines its trust objective as: "the RO trusts the AS to ensure GNAP defines its trust objective as: "the RO trusts the AS to ensure
access validation and delegation of protected resources to end users, access validation and delegation of protected resources to end users,
through third party clients." through third party clients."
This trust objective can be decomposed into trust relationships This trust objective can be decomposed into trust relationships
between software elements and roles, especially the pairs end user/ between software elements and roles, especially the pairs end user/
RO, end user/client, client/AS, RS/RO, AS/RO, AS/RS. Trust of an RO, end user/client, client/AS, RS/RO, AS/RO, and AS/RS. Trust of an
agent by its pair can exist if the pair is informed that the agent agent by its pair can exist if the pair is informed that the agent
has made a promise to follow the protocol in the past (e.g. pre- has made a promise to follow the protocol in the past (e.g., pre-
registration, uncompromised cryptographic components) or if the pair registration and uncompromised cryptographic components) or if the
is able to infer by indirect means that the agent has made such a pair is able to infer by indirect means that the agent has made such
promise (e.g. a compliant client request). Each agent defines its a promise (e.g., a compliant client request). Each agent defines its
own valuation function of promises given or received. Examples of own valuation function of promises given or received. Examples of
such valuations can be the benefits from interacting with other such valuations can be the benefits from interacting with other
agents (e.g. safety in client access, interoperability with identity agents (e.g., safety in client access and interoperability with
standards), the cost of following the protocol (including its identity standards), the cost of following the protocol (including
security and privacy requirements and recommendations), a ranking of its security and privacy requirements and recommendations), a ranking
promise importance (e.g. a policy decision made by the AS), the of promise importance (e.g., a policy decision made by the AS), the
assessment of one's vulnerability or risk of not being able to defend assessment of one's vulnerability or risk of not being able to defend
against threats, etc. Those valuations may depend on the context of against threats, etc. Those valuations may depend on the context of
the request. For instance, the AS may decide to either take into the request. For instance, depending on the specific case in which
account or discard hints provided by the client, the RS may refuse GNAP is used, the AS may decide to either take into account or
bearer tokens, etc. depending on the specific case in which GNAP is discard hints provided by the client, or the RS may refuse bearer
used. Some promises can be affected by previous interactions (e.g., tokens. Some promises can be affected by previous interactions
repeated requests). (e.g., repeated requests).
Looking back on each trust relationship: Below are details of each trust relationship:
* end user/RO: this relationship exists only when the end user and end user/RO: This relationship exists only when the end user and the
the RO are different, in which case the end user needs some out of RO are different, in which case the end user needs some out-of-
band mechanism of getting the RO consent (see Section 4). GNAP band mechanism of getting the RO consent (see Section 4). GNAP
generally assumes that humans can be authenticated thanks to generally assumes that humans can be authenticated, thanks to
identity protocols (for instance, through an id_token assertion in identity protocols (for instance, through an id_token assertion as
Section 2.2). described in Section 2.2).
* end user/client: the client acts as a user agent. Depending on end user/client: The client acts as a user agent. Depending on the
the technology used (browser, SPA, mobile application, IoT device, technology used (browser, single-page application (SPA), mobile
etc.), some interactions may or may not be possible (as described application, Internet of Things (IoT) device, etc.), some
in Section 2.5.1). Client developers implement requirements and interactions may or may not be possible (as described in
Section 2.5.1). Client developers implement requirements and
generally some recommendations or best practices, so that the end generally some recommendations or best practices, so that the end
users may confidently use their software. However, end users users may confidently use their software. However, end users
might also be facing an attacker's client software or a poorly- might also face an attacker's client software or a poorly
implemented client, without even realizing it. implemented client without even realizing it.
* end user/AS: when the client supports the interaction feature (see end user/AS: When the client supports the interaction feature (see
Section 3.3), the end user interacts with the AS through an AS- Section 3.3), the end user interacts with the AS through an AS-
provided interface. In many cases, this happens through a front- provided interface. In many cases, this happens through a front-
channel interaction through the end user's browser. See channel interaction through the end user's browser. See
Section 13.29 for some considerations in trusting these Section 11.29 for some considerations in trusting these
interactions. interactions.
* client/AS: An honest AS may be facing an attacker's client (as client/AS: An honest AS may face an attacker's client (as discussed
discussed just above), or the reverse, and GNAP aims at making just above), or the reverse, and GNAP aims to make common attacks
common attacks impractical. The core specification makes access impractical. The core specification makes access tokens opaque to
tokens opaque to the client and defines the request/response the client and defines the request/response scheme in detail,
scheme in detail, therefore avoiding extra trust hypotheses from therefore avoiding extra trust hypotheses from this critical piece
this critical piece of software. Yet the AS may further define of software. Yet, the AS may further define cryptographic
cryptographic attestations or optional rules to simplify the attestations or optional rules to simplify the access of clients
access of clients it already trusts, due to past behavior or it already trusts, due to past behavior or organizational policies
organizational policies (see Section 2.3). (see Section 2.3).
* RS/RO: the RS promises it protects its resources on behalf of the RS/RO: On behalf of the RO, the RS promises to protect its resources
RO from unauthorized access, and only accepts valid access tokens from unauthorized access and only accepts valid access tokens
issued by a trusted AS. In case tokens are key bound, proper issued by a trusted AS. In case tokens are key bound, proper
validation of the proof method is expected from the RS. validation of the proof method is expected from the RS.
* AS/RO: the AS is expected to follow the decisions made by the RO, AS/RO: The AS is expected to follow the decisions made by the RO,
either through interactive consent requests, repeated through either interactive consent requests, repeated
interactions, or automated rules (as described in Section 1.6). interactions, or automated rules (as described in Section 1.6).
Privacy considerations aim to reduce the risk of an honest but Privacy considerations aim to reduce the risk of an honest but
too-curious AS, or the consequences of an unexpected user data too-curious AS or the consequences of an unexpected user data
exposure. exposure.
* AS/RS: the AS promises to issue valid access tokens to legitimate AS/RS: The AS promises to issue valid access tokens to legitimate
client requests (i.e. after carrying out appropriate due client requests (i.e., after carrying out appropriate due
diligence, as defined in the GNAP protocol). Some optional diligence, as defined in the GNAP protocol). Some optional
configurations are covered by [I-D.ietf-gnap-resource-servers]. configurations are covered by [GNAP-RS].
A global assumption made by GNAP is that authorization requests are A global assumption made by GNAP is that authorization requests are
security and privacy sensitive, and appropriate measures are security and privacy sensitive, and appropriate measures are detailed
respectively detailed in Section 13 and Section 14. in Sections 11 and 12, respectively.
A formal trust model is out of scope of this specification, but one A formal trust model is out of scope of this specification, but one
could be developed using techniques such as [promise-theory]. could be developed using techniques such as [promise-theory].
1.5. Protocol Flow 1.5. Protocol Flow
GNAP is fundamentally designed to allow delegated access to APIs and GNAP is fundamentally designed to allow delegated access to APIs and
other information, such as subject information, using a multi-stage, other information, such as subject information, using a multi-stage,
stateful process. This process allows different parties to provide stateful process. This process allows different parties to provide
information into the system to alter and augment the state of the information into the system to alter and augment the state of the
delegated access and its artifacts. delegated access and its artifacts.
The underlying requested grant moves through several states as The underlying requested grant moves through several states as
different actions take place during the protocol: different actions take place during the protocol, as shown in
Figure 2.
.-----. .-----.
| | | |
+------+--+ | Continue +------+--+ | Continue
.---Need Interaction---->| | | .---Need Interaction---->| | |
/ | Pending |<--` / | Pending |<--`
/ .--Finish Interaction--+ | / .--Finish Interaction--+ |
/ / (approve/deny) +----+----+ / / (approve/deny) +----+----+
/ / | / / |
/ / | Cancel / / | Cancel
skipping to change at page 14, line 5 skipping to change at line 617
\ \ | Revoke or \ \ | Revoke or
\ \ | Finalize \ \ | Finalize
\ \ +-----+----+ \ \ +-----+----+
\ `-----Update---------+ | \ `-----Update---------+ |
\ | Approved |<--. \ | Approved |<--.
`-----No Interaction--->| | | `-----No Interaction--->| | |
+-------+--+ | Continue +-------+--+ | Continue
| | | |
`-----` `-----`
Figure 2: Figure 2: State diagram of a grant request throughout GNAP Figure 2: State Diagram of a Grant Request throughout GNAP
The state of the grant request is defined and managed by the AS, The state of the grant request is defined and managed by the AS,
though the client instance also needs to manage its view of the grant though the client instance also needs to manage its view of the grant
request over time. The means by which these roles manage their state request over time. The means by which these roles manage their state
is outside the scope of this specification. are outside the scope of this specification.
_Processing_: When a request for access (Section 2) is received by _Processing_: When a request for access (Section 2) is received by
the AS, a new grant request is created and placed in the the AS, a new grant request is created and placed in the
_processing_ state by the AS. This state is also entered when an _processing_ state by the AS. This state is also entered when an
existing grant request is updated by the client instance and when existing grant request is updated by the client instance and when
interaction is completed. In this state, the AS processes the interaction is completed. In this state, the AS processes the
context of the grant request to determine whether interaction with context of the grant request to determine whether interaction with
the end user or RO is required for approval of the request. The the end user or RO is required for approval of the request. The
grant request has to exit this state before a response can be grant request has to exit this state before a response can be
returned to the client instance. If approval is required, the returned to the client instance. If approval is required, the
request moves to the _pending_ state and the AS returns a continue request moves to the _pending_ state, and the AS returns a
response (Section 3.1) along with any appropriate interaction continue response (Section 3.1) along with any appropriate
responses (Section 3.3). If no such approval is required, such as interaction responses (Section 3.3). If no such approval is
when the client instance is acting on its own behalf or the AS can required, such as when the client instance is acting on its own
determine that access has been fulfilled, the request moves to the behalf or the AS can determine that access has been fulfilled, the
_approved_ state where access tokens for API access (Section 3.2) request moves to the _approved_ state where access tokens for API
and subject information (Section 3.4) can be issued to the client access (Section 3.2) and subject information (Section 3.4) can be
instance. If the AS determines that no additional processing can issued to the client instance. If the AS determines that no
occur (such as a timeout or an unrecoverable error), the grant additional processing can occur (such as a timeout or an
request is moved to the _finalized_ state and is terminated. unrecoverable error), the grant request is moved to the
_finalized_ state and is terminated.
_Pending_: When a request needs to be approved by a RO, or _Pending_: When a request needs to be approved by an RO, or
interaction with the end user is required, the grant request interaction with the end user is required, the grant request
enters a state of _pending_. In this state, no access tokens can enters a state of _pending_. In this state, no access tokens can
be granted and no subject information can be released to the be granted, and no subject information can be released to the
client instance. While a grant request is in this state, the AS client instance. While a grant request is in this state, the AS
seeks to gather the required consent and authorization (Section 4) seeks to gather the required consent and authorization (Section 4)
for the requested access. A grant request in this state is always for the requested access. A grant request in this state is always
associated with a _continuation access token_ bound to the client associated with a _continuation access token_ bound to the client
instance's key (see Section 3.1 for details of the continuation instance's key (see Section 3.1 for details of the continuation
access token). If no interaction finish method (Section 2.5.2) is access token). If no interaction finish method (Section 2.5.2) is
associated with this request, the client instance can send a associated with this request, the client instance can send a
polling continue request (Section 5.2) to the AS. This returns a polling continue request (Section 5.2) to the AS. This returns a
continue response (Section 3.1) while the grant request remains in continue response (Section 3.1) while the grant request remains in
this state, allowing the client instance to continue to check the this state, allowing the client instance to continue to check the
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client instance can continue the request after interaction client instance can continue the request after interaction
(Section 5.1) to the AS to move this request to the _processing_ (Section 5.1) to the AS to move this request to the _processing_
state to be re-evaluated by the AS. Note that this occurs whether state to be re-evaluated by the AS. Note that this occurs whether
the grant request has been approved or denied by the RO, since the the grant request has been approved or denied by the RO, since the
AS needs to take into account the full context of the request AS needs to take into account the full context of the request
before determining the next step for the grant request. When before determining the next step for the grant request. When
other information is made available in the context of the grant other information is made available in the context of the grant
request, such as through the asynchronous actions of the RO, the request, such as through the asynchronous actions of the RO, the
AS moves this request to the _processing_ state to be re- AS moves this request to the _processing_ state to be re-
evaluated. If the AS determines that no additional interaction evaluated. If the AS determines that no additional interaction
can occur, such as all the interaction methods have timed out or a can occur, e.g., all the interaction methods have timed out or a
revocation request (Section 5.4) is received from the client revocation request (Section 5.4) is received from the client
instance, the grant request can be moved to the _finalized_ state. instance, the grant request can be moved to the _finalized_ state.
_Approved_: When a request has been approved by an RO and no further _Approved_: When a request has been approved by an RO and no further
interaction with the end user is required, the grant request interaction with the end user is required, the grant request
enters a state of _approved_. In this state, responses to the enters a state of _approved_. In this state, responses to the
client instance can include access tokens for API access client instance can include access tokens for API access
(Section 3.2) and subject information (Section 3.4). If (Section 3.2) and subject information (Section 3.4). If
continuation and updates are allowed for this grant request, the continuation and updates are allowed for this grant request, the
AS can include the continuation response (Section 3.1). In this AS can include the continuation response (Section 3.1). In this
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not allowed and will result in an error, since all interaction is not allowed and will result in an error, since all interaction is
assumed to have been completed. If the client instance sends a assumed to have been completed. If the client instance sends a
polling continue request (Section 5.2) while the request is in polling continue request (Section 5.2) while the request is in
this state, new access tokens (Section 3.2) can be issued in the this state, new access tokens (Section 3.2) can be issued in the
response. Note that this always creates a new access token, but response. Note that this always creates a new access token, but
any existing access tokens could be rotated and revoked using the any existing access tokens could be rotated and revoked using the
token management API (Section 6). The client instance can send an token management API (Section 6). The client instance can send an
update continuation request (Section 5.3) to modify the requested update continuation request (Section 5.3) to modify the requested
access, causing the AS to move the request back to the access, causing the AS to move the request back to the
_processing_ state for re-evaluation. If the AS determines that _processing_ state for re-evaluation. If the AS determines that
no additional tokens can be issued, and that no additional updates no additional tokens can be issued and that no additional updates
are to be accepted (such as the continuation access tokens have are to be accepted (e.g., the continuation access tokens have
expired), the grant is moved to the _finalized_ state. expired), the grant is moved to the _finalized_ state.
_Finalized_: After the access tokens are issued, if the AS does not _Finalized_: After the access tokens are issued, if the AS does not
allow any additional updates on the grant request, the grant allow any additional updates on the grant request, the grant
request enters the _finalized_ state. This state is also entered request enters the _finalized_ state. This state is also entered
when an existing grant request is revoked by the client instance when an existing grant request is revoked by the client instance
(Section 5.4) or otherwise revoked by the AS (such as through out- (Section 5.4) or otherwise revoked by the AS (such as through out-
of-band action by the RO). This state can also be entered if the of-band action by the RO). This state can also be entered if the
AS determines that no additional processing is possible, for AS determines that no additional processing is possible, for
example if the RO has denied the requested access or if example, if the RO has denied the requested access or if
interaction is required but no compatible interaction methods are interaction is required but no compatible interaction methods are
available. Once in this state, no new access tokens can be available. Once in this state, no new access tokens can be
issued, no subject information can be returned, and no issued, no subject information can be returned, and no
interactions can take place. Once in this state, the grant interactions can take place. Once in this state, the grant
request is dead and cannot be revived. If future access is request is dead and cannot be revived. If future access is
desired by the client instance, a new grant request can be desired by the client instance, a new grant request can be
created, unrelated to this grant request. created, unrelated to this grant request.
While it is possible to deploy an AS in a stateless environment, GNAP While it is possible to deploy an AS in a stateless environment, GNAP
is a stateful protocol and such deployments will need a way to manage is a stateful protocol, and such deployments will need a way to
the current state of the grant request in a secure and deterministic manage the current state of the grant request in a secure and
fashion without relying on other components, such as the client deterministic fashion without relying on other components, such as
software, to keep track of the current state. the client software, to keep track of the current state.
1.6. Sequences 1.6. Sequences
GNAP can be used in a variety of ways to allow the core delegation GNAP can be used in a variety of ways to allow the core delegation
process to take place. Many portions of this process are process to take place. Many portions of this process are
conditionally present depending on the context of the deployments, conditionally present depending on the context of the deployments,
and not every step in this overview will happen in all circumstances. and not every step in this overview will happen in all circumstances.
Note that a connection between roles in this process does not Note that a connection between roles in this process does not
necessarily indicate that a specific protocol message is sent across necessarily indicate that a specific protocol message is sent across
the wire between the components fulfilling the roles in question, or the wire between the components fulfilling the roles in question or
that a particular step is required every time. For example, for a that a particular step is required every time. For example, for a
client instance interested in only getting subject information client instance interested in only getting subject information
directly, and not calling an RS, all steps involving the RS below do directly and not calling an RS, all steps involving the RS below do
not apply. not apply.
In some circumstances, the information needed at a given stage is In some circumstances, the information needed at a given stage is
communicated out of band or is preconfigured between the components communicated out of band or is pre-configured between the components
or entities performing the roles. For example, one entity can or entities performing the roles. For example, one entity can
fulfill multiple roles, and so explicit communication between the fulfill multiple roles, so explicit communication between the roles
roles is not necessary within the protocol flow. Additionally some is not necessary within the protocol flow. Additionally, some
components may not be involved in all use cases. For example, a components may not be involved in all use cases. For example, a
client instance could be calling the AS just to get direct user client instance could be calling the AS just to get direct user
information and have no need to get an access token to call an RS. information and have no need to get an access token to call an RS.
1.6.1. Overall Protocol Sequence 1.6.1. Overall Protocol Sequence
The following diagram provides a general overview of GNAP, including The following diagram provides a general overview of GNAP, including
many different optional phases and connections. The diagrams in the many different optional phases and connections. The diagrams in the
following sections provide views of GNAP under more specific following sections provide views of GNAP under more specific
circumstances. These additional diagrams use the same conventions as circumstances. These additional diagrams use the same conventions as
skipping to change at page 17, line 37 skipping to change at line 783
| | | | | | | | | | | |
| +--(9)-->| | | | | +--(9)-->| | | |
| |<-(10)--+ | | | | |<-(10)--+ | | |
| | | | | | | | | | | |
| +---------------(11)------------>| | | +---------------(11)------------>| |
| | | | (12) | | | | | | (12) | |
| +--(13)->| | | | | +--(13)->| | | |
| | | | | | | | | | | |
+--------+ +---------------+ +------------+ +--------+ +---------------+ +------------+
Legend Legend:
===== indicates a possible interaction with a human ===== indicates a possible interaction with a human
----- indicates an interaction between protocol roles ----- indicates an interaction between protocol roles
~ ~ ~ indicates a potential equivalence or out-of-band ~ ~ ~ indicates a potential equivalence or out-of-band
communication between roles communication between roles
Figure 3: Figure 3: Overall sequence of GNAP Figure 3: Overall Sequence of GNAP
* (A) The end user interacts with the client instance to indicate a * (A) The end user interacts with the client instance to indicate a
need for resources on behalf of the RO. This could identify the need for resources on behalf of the RO. This could identify the
RS the client instance needs to call, the resources needed, or the RS that the client instance needs to call, the resources needed,
RO that is needed to approve the request. Note that the RO and or the RO that is needed to approve the request. Note that the RO
end user are often the same entity in practice, but GNAP makes no and end user are often the same entity in practice, but GNAP makes
general assumption that they are. no general assumption that they are.
* (1) The client instance determines what access is needed and which * (1) The client instance determines what access is needed and which
AS to approach for access. Note that for most situations, the AS to approach for access. Note that for most situations, the
client instance is pre-configured with which AS to talk to and client instance is pre-configured with which AS to talk to and
which kinds of access it needs, but some more dynamic processes which kinds of access it needs, but some more dynamic processes
are discussed in Section 9.1. are discussed in Section 9.1.
* (2) The client instance requests access at the AS (Section 2). * (2) The client instance requests access at the AS (Section 2).
* (3) The AS processes the request and determines what is needed to * (3) The AS processes the request and determines what is needed to
fulfill the request (See Section 4). The AS sends its response to fulfill the request (see Section 4). The AS sends its response to
the client instance (Section 3). the client instance (Section 3).
* (B) If interaction is required, the AS interacts with the RO * (B) If interaction is required, the AS interacts with the RO
(Section 4) to gather authorization. The interactive component of (Section 4) to gather authorization. The interactive component of
the AS can function using a variety of possible mechanisms the AS can function using a variety of possible mechanisms,
including web page redirects, applications, challenge/response including web page redirects, applications, challenge/response
protocols, or other methods. The RO approves the request for the protocols, or other methods. The RO approves the request for the
client instance being operated by the end user. Note that the RO client instance being operated by the end user. Note that the RO
and end user are often the same entity in practice, and many of and end user are often the same entity in practice, and many of
GNAP's interaction methods allow the client instance to facilitate GNAP's interaction methods allow the client instance to facilitate
the end user interacting with the AS in order to fulfill the role the end user interacting with the AS in order to fulfill the role
of the RO. of the RO.
* (4) The client instance continues the grant at the AS (Section 5). * (4) The client instance continues the grant at the AS (Section 5).
This action could occur in response to receiving a signal that This action could occur in response to receiving a signal that
interaction has finished (Section 4.2) or through a periodic interaction has finished (Section 4.2) or through a periodic
polling mechanism, depending on the interaction capabilities of polling mechanism, depending on the interaction capabilities of
the client software and the options active in the grant request. the client software and the options active in the grant request.
* (5) If the AS determines that access can be granted, it returns a * (5) If the AS determines that access can be granted, it returns a
response to the client instance (Section 3) including an access response to the client instance (Section 3), including an access
token (Section 3.2) for calling the RS and any directly returned token (Section 3.2) for calling the RS and any directly returned
information (Section 3.4) about the RO. information (Section 3.4) about the RO.
* (6) The client instance uses the access token (Section 7.2) to * (6) The client instance uses the access token (Section 7.2) to
call the RS. call the RS.
* (7) The RS determines if the token is sufficient for the request * (7) The RS determines if the token is sufficient for the request
by examining the token. The means of the RS determining this by examining the token. The means of the RS determining this
access are out of scope of this specification, but some options access are out of scope of this specification, but some options
are discussed in [I-D.ietf-gnap-resource-servers]. are discussed in [GNAP-RS].
* (8) The client instance calls the RS (Section 7.2) using the * (8) The client instance calls the RS (Section 7.2) using the
access token until the RS or client instance determine that the access token until the RS or client instance determines that the
token is no longer valid. token is no longer valid.
* (9) When the token no longer works, the client instance rotates * (9) When the token no longer works, the client instance rotates
the access token (Section 6.1). the access token (Section 6.1).
* (10) The AS issues a new access token (Section 3.2) to the client * (10) The AS issues a new access token (Section 3.2) to the client
instance with the same rights as the original access token instance with the same rights as the original access token
returned in (5). returned in (5).
* (11) The client instance uses the new access token (Section 7.2) * (11) The client instance uses the new access token (Section 7.2)
to call the RS. to call the RS.
* (12) The RS determines if the new token is sufficient for the * (12) The RS determines if the new token is sufficient for the
request, as in (7). request, as in (7).
* (13) The client instance disposes of the token (Section 6.2) once * (13) The client instance disposes of the token (Section 6.2) once
the client instance has completed its access of the RS and no the client instance has completed its access of the RS and no
longer needs the token. longer needs the token.
The following sections and Appendix C contain specific guidance on The following sections and Appendix B contain specific guidance on
how to use GNAP in different situations and deployments. For how to use GNAP in different situations and deployments. For
example, it is possible for the client instance to never request an example, it is possible for the client instance to never request an
access token and never call an RS, just as it is possible to have no access token and never call an RS, just as it is possible to have no
end user involved in the delegation process. end user involved in the delegation process.
1.6.2. Redirect-based Interaction 1.6.2. Redirect-Based Interaction
In this example flow, the client instance is a web application that In this example flow, the client instance is a web application that
wants access to resources on behalf of the current user, who acts as wants access to resources on behalf of the current user, who acts as
both the end user and the resource owner (RO). Since the client both the end user and the resource owner (RO). Since the client
instance is capable of directing the user to an arbitrary URI and instance is capable of directing the user to an arbitrary URI and
receiving responses from the user's browser, interaction here is receiving responses from the user's browser, interaction here is
handled through front-channel redirects using the user's browser. handled through front-channel redirects using the user's browser.
The redirection URI used for interaction is a service hosted by the The redirection URI used for interaction is a service hosted by the
AS in this example. The client instance uses a persistent session AS in this example. The client instance uses a persistent session
with the user to ensure the same user that is starting the with the user to ensure the same user that is starting the
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| | | | | | | |
| |<-(9)----- Grant Access ----------+ | | |<-(9)----- Grant Access ----------+ |
| | | | | | | |
| | | | +--------+ | | | | +--------+
| +--(10)-- Access API ---------------------------->| RS | | +--(10)-- Access API ---------------------------->| RS |
| | | | | | | | | | | |
| |<-(11)-- API Response ---------------------------| | | |<-(11)-- API Response ---------------------------| |
| | | | +--------+ | | | | +--------+
+--------+ +--------+ +--------+ +--------+
Figure 4: Figure 4: Diagram of a redirect-based interaction Figure 4: Diagram of a Redirect-Based Interaction
1. The client instance establishes a session with the user, in the 1. The client instance establishes a session with the user, in the
role of the end user. role of the end user.
2. The client instance requests access to the resource (Section 2). 2. The client instance requests access to the resource (Section 2).
The client instance indicates that it can redirect to an The client instance indicates that it can redirect to an
arbitrary URI (Section 2.5.1.1) and receive a redirect from the arbitrary URI (Section 2.5.1.1) and receive a redirect from the
browser (Section 2.5.2.1). The client instance stores browser (Section 2.5.2.1). The client instance stores
verification information for its redirect in the session created verification information for its redirect in the session created
in (1). in (1).
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the hash validates. Note that the client instance needs to the hash validates. Note that the client instance needs to
ensure that the parameters for the incoming request match those ensure that the parameters for the incoming request match those
that it is expecting from the session created in (1). The that it is expecting from the session created in (1). The
client instance also needs to be prepared for the end user never client instance also needs to be prepared for the end user never
being returned to the client instance and handle timeouts being returned to the client instance and handle timeouts
appropriately. appropriately.
8. The client instance loads the continuation information from (3) 8. The client instance loads the continuation information from (3)
and sends the interaction reference from (7) in a request to and sends the interaction reference from (7) in a request to
continue the request (Section 5.1). The AS validates the continue the request (Section 5.1). The AS validates the
interaction reference ensuring that the reference is associated interaction reference, ensuring that the reference is associated
with the request being continued. with the request being continued.
9. If the request has been authorized, the AS grants access to the 9. If the request has been authorized, the AS grants access to the
information in the form of access tokens (Section 3.2) and information in the form of access tokens (Section 3.2) and
direct subject information (Section 3.4) to the client instance. direct subject information (Section 3.4) to the client instance.
10. The client instance uses the access token (Section 7.2) to call 10. The client instance uses the access token (Section 7.2) to call
the RS. the RS.
11. The RS validates the access token and returns an appropriate 11. The RS validates the access token and returns an appropriate
response for the API. response for the API.
An example set of protocol messages for this method can be found in An example set of protocol messages for this method can be found in
Appendix C.1. Appendix B.1.
1.6.3. User-code Interaction 1.6.3. User Code Interaction
In this example flow, the client instance is a device that is capable In this example flow, the client instance is a device that is capable
of presenting a short, human-readable code to the user and directing of presenting a short, human-readable code to the user and directing
the user to enter that code at a known URI. The user enters the code the user to enter that code at a known URI. The user enters the code
at a URI that is an interactive service hosted by the AS in this at a URI that is an interactive service hosted by the AS in this
example. The client instance is not capable of presenting an example. The client instance is not capable of presenting an
arbitrary URI to the user, nor is it capable of accepting incoming arbitrary URI to the user, nor is it capable of accepting incoming
HTTP requests from the user's browser. The client instance polls the HTTP requests from the user's browser. The client instance polls the
AS while it is waiting for the RO to authorize the request. The AS while it is waiting for the RO to authorize the request. The
user's interaction is assumed to occur on a secondary device. In user's interaction is assumed to occur on a secondary device. In
this example it is assumed that the user is both the end user and RO. this example, it is assumed that the user is both the end user and
Note that since the user is not assumed to be interacting with the RO. Note that since the user is not assumed to be interacting with
client instance through the same web browser used for interaction at the client instance through the same web browser used for interaction
the AS, the user is not shown as being connected to the client at the AS, the user is not shown as being connected to the client
instance in this diagram. instance in this diagram.
+--------+ +--------+ .----. +--------+ +--------+ .----.
| Client | | AS | | End | | Client | | AS | | End |
|Instance+--(1)--- Request Access --------->| | | User | |Instance+--(1)--- Request Access --------->| | | User |
| | | | | | | | | | | |
| |<-(2)-- Interaction Needed -------+ | | | | |<-(2)-- Interaction Needed -------+ | | |
| | | | | | | | | | | |
| +==(3)==== Display User Code ========================>| | | +==(3)==== Display User Code ========================>| |
| | | | | | | | | | | |
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| | | | | User | | | | | | User |
| |<-(12)----- Grant Access ---------+ | `----` | |<-(12)----- Grant Access ---------+ | `----`
| | | | | | | |
| | | | +--------+ | | | | +--------+
| +--(13)-- Access API ---------------------------->| RS | | +--(13)-- Access API ---------------------------->| RS |
| | | | | | | | | | | |
| |<-(14)-- API Response ---------------------------+ | | |<-(14)-- API Response ---------------------------+ |
| | | | +--------+ | | | | +--------+
+--------+ +--------+ +--------+ +--------+
Figure 5: Figure 5: Diagram of a user-code-based interaction Figure 5: Diagram of a User-Code-Based Interaction
1. The client instance requests access to the resource (Section 2). 1. The client instance requests access to the resource (Section 2).
The client instance indicates that it can display a user code The client instance indicates that it can display a user code
(Section 2.5.1.3). (Section 2.5.1.3).
2. The AS determines that interaction is needed and responds 2. The AS determines that interaction is needed and responds
(Section 3) with a user code to communicate to the user (Section 3) with a user code to communicate to the user
(Section 3.3.3). The AS also includes information the client (Section 3.3.3). The AS also includes information the client
instance will need to continue the request (Section 3.1) in (8) instance will need to continue the request (Section 3.1) in (8)
and (10). The AS associates this continuation information with and (10). The AS associates this continuation information with
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information in the form of access tokens (Section 3.2) and information in the form of access tokens (Section 3.2) and
direct subject information (Section 3.4) to the client instance. direct subject information (Section 3.4) to the client instance.
13. The client instance uses the access token (Section 7.2) to call 13. The client instance uses the access token (Section 7.2) to call
the RS. the RS.
14. The RS validates the access token and returns an appropriate 14. The RS validates the access token and returns an appropriate
response for the API. response for the API.
An example set of protocol messages for this method can be found in An example set of protocol messages for this method can be found in
Appendix C.2. Appendix B.2.
1.6.4. Asynchronous Authorization 1.6.4. Asynchronous Authorization
In this example flow, the end user and RO roles are fulfilled by In this example flow, the end user and RO roles are fulfilled by
different parties, and the RO does not interact with the client different parties, and the RO does not interact with the client
instance. The AS reaches out asynchronously to the RO during the instance. The AS reaches out asynchronously to the RO during the
request process to gather the RO's authorization for the client request process to gather the RO's authorization for the client
instance's request. The client instance polls the AS while it is instance's request. The client instance polls the AS while it is
waiting for the RO to authorize the request. waiting for the RO to authorize the request.
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| | | | | | | |
| |<-(9)------ Grant Access ---------+ | | |<-(9)------ Grant Access ---------+ |
| | | | | | | |
| | | | +--------+ | | | | +--------+
| +--(10)-- Access API ---------------------------->| RS | | +--(10)-- Access API ---------------------------->| RS |
| | | | | | | | | | | |
| |<-(11)-- API Response ---------------------------+ | | |<-(11)-- API Response ---------------------------+ |
| | | | +--------+ | | | | +--------+
+--------+ +--------+ +--------+ +--------+
Figure 6: Figure 6: Diagram of an asynchronous authorization Figure 6: Diagram of an Asynchronous Authorization Process, with
process, with no end user interaction No End-User Interaction
1. The client instance requests access to the resource (Section 2). 1. The client instance requests access to the resource (Section 2).
The client instance does not send any interaction modes to the The client instance does not send any interaction modes to the
server, indicating that it does not expect to interact with the server, indicating that it does not expect to interact with the
RO. The client instance can also signal which RO it requires RO. The client instance can also signal which RO it requires
authorization from, if known, by using the subject request authorization from, if known, by using the subject request
(Section 2.2) and user request (Section 2.4) sections. It's section (Section 2.2) and user request section (Section 2.4).
also possible for the AS to determine which RO needs to be It's also possible for the AS to determine which RO needs to be
contacted by the nature of what access is being requested. contacted by the nature of what access is being requested.
2. The AS determines that interaction is needed, but the client 2. The AS determines that interaction is needed, but the client
instance cannot interact with the RO. The AS responds instance cannot interact with the RO. The AS responds
(Section 3) with the information the client instance will need (Section 3) with the information the client instance will need
to continue the request (Section 3.1) in (6) and (8), including to continue the request (Section 3.1) in (6) and (8), including
a signal that the client instance should wait before checking a signal that the client instance should wait before checking
the status of the request again. The AS associates this the status of the request again. The AS associates this
continuation information with an ongoing request that will be continuation information with an ongoing request that will be
referenced in (3), (4), (5), (6), and (8). referenced in (3), (4), (5), (6), and (8).
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information in the form of access tokens (Section 3.2) and information in the form of access tokens (Section 3.2) and
direct subject information (Section 3.4) to the client instance. direct subject information (Section 3.4) to the client instance.
10. The client instance uses the access token (Section 7.2) to call 10. The client instance uses the access token (Section 7.2) to call
the RS. the RS.
11. The RS validates the access token and returns an appropriate 11. The RS validates the access token and returns an appropriate
response for the API. response for the API.
An example set of protocol messages for this method can be found in An example set of protocol messages for this method can be found in
Appendix C.4. Appendix B.4.
Additional considerations for asynchronous interactions like this are Additional considerations for asynchronous interactions like this are
discussed in Section 13.36. discussed in Section 11.36.
1.6.5. Software-only Authorization 1.6.5. Software-Only Authorization
In this example flow, the AS policy allows the client instance to In this example flow, the AS policy allows the client instance to
make a call on its own behalf, without the need for an RO to be make a call on its own behalf, without the need for an RO to be
involved at runtime to approve the decision. Since there is no involved at runtime to approve the decision. Since there is no
explicit RO, the client instance does not interact with an RO. explicit RO, the client instance does not interact with an RO.
+--------+ +--------+ +--------+ +--------+
| Client | | AS | | Client | | AS |
|Instance+--(1)--- Request Access --->| | |Instance+--(1)--- Request Access --->| |
| | | | | | | |
| |<-(2)---- Grant Access -----+ | | |<-(2)---- Grant Access -----+ |
| | | | +--------+ | | | | +--------+
| +--(3)--- Access API ------------------->| RS | | +--(3)--- Access API ------------------->| RS |
| | | | | | | | | | | |
| |<-(4)--- API Response ------------------+ | | |<-(4)--- API Response ------------------+ |
| | | | +--------+ | | | | +--------+
+--------+ +--------+ +--------+ +--------+
Figure 7: Figure 7: Diagram of a software-only authorization, Figure 7: Diagram of a Software-Only Authorization, with No End
with no end user or explicit resource owner User or Explicit Resource Owner
1. The client instance requests access to the resource (Section 2). 1. The client instance requests access to the resource (Section 2).
The client instance does not send any interaction modes to the The client instance does not send any interaction modes to the
server. server.
2. The AS determines that the request has been authorized based on 2. The AS determines that the request has been authorized based on
the identity of the client instance making the request and the the identity of the client instance making the request and the
access requested (Section 2.1). The AS grants access to the access requested (Section 2.1). The AS grants access to the
resource in the form of access tokens (Section 3.2) to the client resource in the form of access tokens (Section 3.2) to the client
instance. Note that direct subject information (Section 3.4) is instance. Note that direct subject information (Section 3.4) is
not generally applicable in this use case, as there is no user not generally applicable in this use case, as there is no user
involved. involved.
3. The client instance uses the access token (Section 7.2) to call 3. The client instance uses the access token (Section 7.2) to call
the RS. the RS.
4. The RS validates the access token and returns an appropriate 4. The RS validates the access token and returns an appropriate
response for the API. response for the API.
An example set of protocol messages for this method can be found in An example set of protocol messages for this method can be found in
Appendix C.3. Appendix B.3.
1.6.6. Refreshing an Expired Access Token 1.6.6. Refreshing an Expired Access Token
In this example flow, the client instance receives an access token to In this example flow, the client instance receives an access token to
access a resource server through some valid GNAP process. The client access a resource server through some valid GNAP process. The client
instance uses that token at the RS for some time, but eventually the instance uses that token at the RS for some time, but eventually the
access token expires. The client instance then gets a refreshed access token expires. The client instance then gets a refreshed
access token by rotating the expired access token's value at the AS access token by rotating the expired access token's value at the AS
using the token management API. using the token management API.
skipping to change at page 29, line 29 skipping to change at line 1277
| | | | | | | | | | | |
| |<-(6)--- Error Response -----+ | | | | |<-(6)--- Error Response -----+ | | |
| | +--------+ | | | | +--------+ | |
| | | | | | | |
| +--(7)--- Rotate Token ------------------->| | | +--(7)--- Rotate Token ------------------->| |
| | | | | | | |
| |<-(8)--- Rotated Token -------------------+ | | |<-(8)--- Rotated Token -------------------+ |
| | | | | | | |
+--------+ +--------+ +--------+ +--------+
Figure 8: Figure 8: Diagram of the process of refreshing an Figure 8: Diagram of the Process of Refreshing an Access Token
access token
1. The client instance requests access to the resource (Section 2). 1. The client instance requests access to the resource (Section 2).
2. The AS grants access to the resource (Section 3) with an access 2. The AS grants access to the resource (Section 3) with an access
token (Section 3.2) usable at the RS. The access token response token (Section 3.2) usable at the RS. The access token response
includes a token management URI. includes a token management URI.
3. The client instance uses the access token (Section 7.2) to call 3. The client instance uses the access token (Section 7.2) to call
the RS. the RS.
skipping to change at page 30, line 8 skipping to change at line 1301
5. Time passes and the client instance uses the access token to call 5. Time passes and the client instance uses the access token to call
the RS again. the RS again.
6. The RS validates the access token and determines that the access 6. The RS validates the access token and determines that the access
token is expired. The RS responds to the client instance with an token is expired. The RS responds to the client instance with an
error. error.
7. The client instance calls the token management URI returned in 7. The client instance calls the token management URI returned in
(2) to rotate the access token (Section 6.1). The client (2) to rotate the access token (Section 6.1). The client
instance uses the access token (Section 7.2) in this call as well instance uses the access token (Section 7.2) in this call as well
as the appropriate key, see the token rotation section for as the appropriate key; see the token rotation section for
details. details.
8. The AS validates the rotation request including the signature and 8. The AS validates the rotation request, including the signature
keys presented in (7) and refreshes the access token and keys presented in (7), and refreshes the access token
(Section 3.2.1). The response includes a new version of the (Section 3.2.1). The response includes a new version of the
access token and can also include updated token management access token and can also include updated token management
information, which the client instance will store in place of the information, which the client instance will store in place of the
values returned in (2). values returned in (2).
1.6.7. Requesting Subject Information Only 1.6.7. Requesting Subject Information Only
In this scenario, the client instance does not call an RS and does In this scenario, the client instance does not call an RS and does
not request an access token. Instead, the client instance only not request an access token. Instead, the client instance only
requests and is returned direct subject information (Section 3.4). requests and is returned direct subject information (Section 3.4).
skipping to change at page 30, line 49 skipping to change at line 1342
| | | | AuthZ +------+ | | | | AuthZ +------+
| | | | | End | | | | | | End |
| |<=(6)== Signal Continuation =========================+ User | | |<=(6)== Signal Continuation =========================+ User |
| | | | `----` | | | | `----`
| +--(7)--- Continue Request ------->| | | +--(7)--- Continue Request ------->| |
| | | | | | | |
| |<-(8)----- Grant Access ----------+ | | |<-(8)----- Grant Access ----------+ |
| | | | | | | |
+--------+ +--------+ +--------+ +--------+
Figure 9: Figure 9: Diagram of the process of requesting and Figure 9: Diagram of the Process of Requesting and Releasing Subject
releasing subject information apart from access tokens Information apart from Access Tokens
1. The client instance requests access to subject information 1. The client instance requests access to subject information
(Section 2). (Section 2).
2. The AS determines that interaction is needed and responds 2. The AS determines that interaction is needed and responds
(Section 3) with appropriate information for facilitating user (Section 3) with appropriate information for facilitating user
interaction (Section 3.3). interaction (Section 3.3).
3. The client instance facilitates the user interacting with the AS 3. The client instance facilitates the user interacting with the AS
(Section 4) as directed in (2). (Section 4) as directed in (2).
skipping to change at page 31, line 31 skipping to change at line 1371
user to the client instance and signals continuation. user to the client instance and signals continuation.
7. The client instance loads the continuation information from (2) 7. The client instance loads the continuation information from (2)
and calls the AS to continue the request (Section 5). and calls the AS to continue the request (Section 5).
8. If the request has been authorized, the AS grants access to the 8. If the request has been authorized, the AS grants access to the
requested direct subject information (Section 3.4) to the client requested direct subject information (Section 3.4) to the client
instance. At this stage, the user is generally considered instance. At this stage, the user is generally considered
"logged in" to the client instance based on the identifiers and "logged in" to the client instance based on the identifiers and
assertions provided by the AS. Note that the AS can restrict the assertions provided by the AS. Note that the AS can restrict the
subject information returned and it might not match what the subject information returned, and it might not match what the
client instance requested, see the section on subject information client instance requested; see the section on subject information
for details. for details.
1.6.8. Cross-User Authentication 1.6.8. Cross-User Authentication
In this scenario, the end user and resource owner are two different In this scenario, the end user and resource owner are two different
people. Here, the client instance already knows who the end user is, people. Here, the client instance already knows who the end user is,
likely through a separate authentication process. The end user, likely through a separate authentication process. The end user,
operating the client instance, needs to get subject information about operating the client instance, needs to get subject information about
another person in the system, the RO. The RO is given an opportunity another person in the system, the RO. The RO is given an opportunity
to release this information using an asynchronous interaction method to release this information using an asynchronous interaction method
with the AS. This scenario would apply, for instance, when the end with the AS. This scenario would apply, for instance, when the end
user is an agent in a call-center and the resource owner is a user is an agent in a call center and the resource owner is a
customer authorizing the call center agent to access their account on customer authorizing the call-center agent to access their account on
their behalf. their behalf.
.----. .----. .----. .----.
| End | | RO | | End | | RO |
| User |<=================(1)== Identify RO ==================>| | | User |<=================(1)== Identify RO ==================>| |
| | | | | | | |
| | +--------+ +--------+ | | | | +--------+ +--------+ | |
| +==(2)==>| Client | | AS | | | | +==(2)==>| Client | | AS | | |
| | RO ID |Instance| | | | | | | RO ID |Instance| | | | |
| | | | | | | | | | | | | | | |
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| | | | | | | | | | | | | | | |
| | | +--(9)--- Cont. -->| | | | | | | +--(9)--- Cont. -->| | | |
| | | | | | | | | | | | | | | |
| | | |<-(10)-- Subj. ---+ | | | | | | |<-(10)-- Subj. ---+ | | |
| |<=(11)==+ | Info | | | | | |<=(11)==+ | Info | | | |
| | Return | | | | | | | | Return | | | | | |
| | RO | | | | | | | | RO | | | | | |
| | Info | | | | | | | | Info | | | | | |
`----` +--------+ +--------+ `----` `----` +--------+ +--------+ `----`
Figure 10: Figure 10: Diagram of cross-user authorization, where Figure 10: Diagram of Cross-User Authorization, Where the End
the end user and RO are different User and RO Are Different
Precondition: The end user is authenticated to the client instance, Precondition: The end user is authenticated to the client instance,
and the client instance has an identifier representing the end user and the client instance has an identifier representing the end user
that it can present to the AS. This identifier should be unique to that it can present to the AS. This identifier should be unique to
the particular session with the client instance and the AS. The the particular session with the client instance and the AS. The
client instance is also known to the AS and allowed to access this client instance is also known to the AS and allowed to access this
advanced functionality where the information of someone other than advanced functionality where the information of someone other than
the end user is returned to the client instance. the end user is returned to the client instance.
1. The RO communicates a human-readable identifier to the end user, 1. The RO communicates a human-readable identifier to the end user,
such as an email address or account number. This communication such as an email address or account number. This communication
happens out of band from the protocol, such as over the phone happens out of band from the protocol, such as over the phone
between parties. Note that the RO is not interacting with the between parties. Note that the RO is not interacting with the
client instance. client instance.
2. The end user communicates the identifier to the client instance. 2. The end user communicates the identifier to the client instance.
The means by which the identifier is communicated to the client The means by which the identifier is communicated to the client
instance is out of scope for this specification. instance are out of scope for this specification.
3. The client instance requests access to subject information 3. The client instance requests access to subject information
(Section 2). The request includes the RO's identifier in the (Section 2). The request includes the RO's identifier in the
subject information request (Section 2.2) sub_ids field, and the subject information request (Section 2.2) sub_ids field and the
end user's identifier in the user information field end user's identifier in the user information field
(Section 2.4) of the request. The request includes no (Section 2.4) of the request. The request includes no
interaction start methods, since the end user is not expected to interaction start methods, since the end user is not expected to
be the one interacting with the AS. The request does include be the one interacting with the AS. The request does include
the push based interaction finish method (Section 2.5.2.2) to the push-based interaction finish method (Section 2.5.2.2) to
allow the AS to signal to the client instance when the allow the AS to signal to the client instance when the
interaction with the RO has concluded. interaction with the RO has concluded.
4. The AS sees that the identifier for the end user and subject 4. The AS sees that the identifiers for the end user and subject
being requested are different. The AS determines that it can being requested are different. The AS determines that it can
reach out to the RO asynchronously for approval. While it is reach out to the RO asynchronously for approval. While it is
doing so, the AS returns a continuation response (Section 3.1) doing so, the AS returns a continuation response (Section 3.1)
with a finish nonce to allow the client instance to continue the with a finish nonce to allow the client instance to continue the
grant request after interaction with the RO has concluded. grant request after interaction with the RO has concluded.
5. The AS contacts the RO and has them authenticate to the system. 5. The AS contacts the RO and has them authenticate to the system.
The means for doing this are outside the scope of this The means for doing this are outside the scope of this
specification, but the identity of the RO is known from the specification, but the identity of the RO is known from the
subject identifier sent in (3). subject identifier sent in (3).
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10. The AS returns the RO's subject information (Section 3.4) to the 10. The AS returns the RO's subject information (Section 3.4) to the
client instance. client instance.
11. The client instance can display or otherwise utilize the RO's 11. The client instance can display or otherwise utilize the RO's
user information in its session with the end user. Note that user information in its session with the end user. Note that
since the client instance requested different sets of user since the client instance requested different sets of user
information in (3), the client instance does not conflate the information in (3), the client instance does not conflate the
end user with the RO. end user with the RO.
Additional considerations for asynchronous interactions like this are Additional considerations for asynchronous interactions like this are
discussed in Section 13.36. discussed in Section 11.36.
2. Requesting Access 2. Requesting Access
To start a request, the client instance sends an HTTP POST with a To start a request, the client instance sends an HTTP POST with a
JSON [RFC8259] document to the grant endpoint of the AS. The grant JSON [RFC8259] document to the grant endpoint of the AS. The grant
endpoint is a URI that uniquely identifies the AS to client instances endpoint is a URI that uniquely identifies the AS to client instances
and serves as the identifier for the AS. The document is a JSON and serves as the identifier for the AS. The document is a JSON
object where each field represents a different aspect of the client object where each field represents a different aspect of the client
instance's request. Each field is described in detail in a section instance's request. Each field is described in detail in a
below. subsection below.
access_token (object / array of objects): Describes the rights and access_token (object / array of objects): Describes the rights and
properties associated with the requested access token. REQUIRED properties associated with the requested access token. REQUIRED
if requesting an access token. See Section 2.1. if requesting an access token. See Section 2.1.
subject (object): Describes the information about the RO that the subject (object): Describes the information about the RO that the
client instance is requesting to be returned directly in the client instance is requesting to be returned directly in the
response from the AS. REQUIRED if requesting subject information. response from the AS. REQUIRED if requesting subject information.
See Section 2.2. See Section 2.2.
client (object / string): Describes the client instance that is client (object / string): Describes the client instance that is
making this request, including the key that the client instance making this request, including the key that the client instance
will use to protect this request and any continuation requests at will use to protect this request, any continuation requests at the
the AS and any user-facing information about the client instance AS, and any user-facing information about the client instance used
used in interactions. REQUIRED. See Section 2.3. in interactions. REQUIRED. See Section 2.3.
user (object / string): Identifies the end user to the AS in a user (object / string): Identifies the end user to the AS in a
manner that the AS can verify, either directly or by interacting manner that the AS can verify, either directly or by interacting
with the end user to determine their status as the RO. OPTIONAL. with the end user to determine their status as the RO. OPTIONAL.
See Section 2.4. See Section 2.4.
interact (object): Describes the modes that the client instance interact (object): Describes the modes that the client instance
supports for allowing the RO to interact with the AS and modes for supports for allowing the RO to interact with the AS and modes for
the client instance to receive updates when interaction is the client instance to receive updates when interaction is
complete. REQUIRED if interaction is supported. See Section 2.5. complete. REQUIRED if interaction is supported. See Section 2.5.
Additional members of this request object can be defined by Additional members of this request object can be defined by
extensions using the GNAP Grant Request Parameters Registry extensions using the "GNAP Grant Request Parameters" registry
(Section 11.3). (Section 10.3).
A non-normative example of a grant request is below: A non-normative example of a grant request is below:
{ {
"access_token": { "access_token": {
"access": [ "access": [
{ {
"type": "photo-api", "type": "photo-api",
"actions": [ "actions": [
"read", "read",
skipping to change at page 36, line 13 skipping to change at line 1586
}, },
"subject": { "subject": {
"sub_id_formats": ["iss_sub", "opaque"], "sub_id_formats": ["iss_sub", "opaque"],
"assertion_formats": ["id_token"] "assertion_formats": ["id_token"]
} }
} }
Sending a request to the grant endpoint creates a grant request in Sending a request to the grant endpoint creates a grant request in
the _processing_ state. The AS processes this request to determine the _processing_ state. The AS processes this request to determine
whether interaction or authorization are necessary (moving to the whether interaction or authorization are necessary (moving to the
_pending_ state), or if access can be granted immediately (moving to _pending_ state) or if access can be granted immediately (moving to
the _approved_ state). the _approved_ state).
The request MUST be sent as a JSON object in the content of the HTTP The request MUST be sent as a JSON object in the content of the HTTP
POST request with Content-Type application/json. A key proofing POST request with Content-Type application/json. A key proofing
mechanism MAY define an alternative content type, as long as the mechanism MAY define an alternative content type, as long as the
content is formed from the JSON object. For example, the attached content is formed from the JSON object. For example, the attached
JWS key proofing mechanism (see Section 7.3.4) places the JSON object JSON Web Signature (JWS) key proofing mechanism (see Section 7.3.4)
into the payload of a JWS wrapper, which is in turn sent as the places the JSON object into the payload of a JWS wrapper, which is in
message content. turn sent as the message content.
2.1. Requesting Access to Resources 2.1. Requesting Access to Resources
If the client instance is requesting one or more access tokens for If the client instance is requesting one or more access tokens for
the purpose of accessing an API, the client instance MUST include an the purpose of accessing an API, the client instance MUST include an
access_token field. This field MUST be an object (for a single access_token field. This field MUST be an object (for a single
access token (Section 2.1.1)) or an array of these objects (for access token (Section 2.1.1)) or an array of these objects (for
multiple access tokens (Section 2.1.2)), as described in the multiple access tokens (Section 2.1.2)), as described in the
following sections. following subsections.
2.1.1. Requesting a Single Access Token 2.1.1. Requesting a Single Access Token
To request a single access token, the client instance sends an To request a single access token, the client instance sends an
access_token object composed of the following fields. access_token object composed of the following fields.
access (array of objects/strings): Describes the rights that the access (array of objects/strings): Describes the rights that the
client instance is requesting for the access token to be used at client instance is requesting for the access token to be used at
the RS. REQUIRED. See Section 8. the RS. REQUIRED. See Section 8.
label (string): A unique name chosen by the client instance to refer label (string): A unique name chosen by the client instance to refer
to the resulting access token. The value of this field is opaque to the resulting access token. The value of this field is opaque
to the AS and is not intended to be exposed to or used by the end to the AS and is not intended to be exposed to or used by the end
user. If this field is included in the request, the AS MUST user. If this field is included in the request, the AS MUST
include the same label in the token response (Section 3.2). include the same label in the token response (Section 3.2).
REQUIRED if used as part of a multiple access token request REQUIRED if used as part of a multiple access tokens request
(Section 2.1.2), OPTIONAL otherwise. (Section 2.1.2); OPTIONAL otherwise.
flags (array of strings): A set of flags that indicate desired flags (array of strings): A set of flags that indicate desired
attributes or behavior to be attached to the access token by the attributes or behavior to be attached to the access token by the
AS. OPTIONAL. AS. OPTIONAL.
The values of the flags field defined by this specification are as The values of the flags field defined by this specification are as
follows: follows:
"bearer": If this flag is included, the access token being requested "bearer": If this flag is included, the access token being requested
is a bearer token. If this flag is omitted, the access token is is a bearer token. If this flag is omitted, the access token is
bound to the key used by the client instance in this request (or bound to the key used by the client instance in this request (or
that key's most recent rotation) and the access token MUST be that key's most recent rotation), and the access token MUST be
presented using the same key and proofing method. Methods for presented using the same key and proofing method. Methods for
presenting bound and bearer access tokens are described in presenting bound and bearer access tokens are described in
Section 7.2. See Section 13.9 for additional considerations on Section 7.2. See Section 11.9 for additional considerations on
the use of bearer tokens. the use of bearer tokens.
Flag values MUST NOT be included more than once. If the request Flag values MUST NOT be included more than once. If the request
includes a flag value multiple times, the AS MUST return an includes a flag value multiple times, the AS MUST return an
invalid_flag error defined in Section 3.6. invalid_flag error defined in Section 3.6.
Additional flags can be defined by extensions using the GNAP Access Additional flags can be defined by extensions using the "GNAP Access
Token Flags Registry (Section 11.4). Token Flags" registry (Section 10.4).
In the following non-normative example, the client instance is In the following non-normative example, the client instance is
requesting access to a complex resource described by a pair of access requesting access to a complex resource described by a pair of access
request object. request object.
"access_token": { "access_token": {
"access": [ "access": [
{ {
"type": "photo-api", "type": "photo-api",
"actions": [ "actions": [
skipping to change at page 39, line 7 skipping to change at line 1695
} }
If access is approved, the resulting access token is valid for the If access is approved, the resulting access token is valid for the
described resource. Since the "bearer" flag is not provided in this described resource. Since the "bearer" flag is not provided in this
example, the token is bound to the client instance's key (or its most example, the token is bound to the client instance's key (or its most
recent rotation). The token is labeled "token1-23". The token recent rotation). The token is labeled "token1-23". The token
response structure is described in Section 3.2.1. response structure is described in Section 3.2.1.
2.1.2. Requesting Multiple Access Tokens 2.1.2. Requesting Multiple Access Tokens
To request multiple access tokens to be returned in a single To request that multiple access tokens be returned in a single
response, the client instance sends an array of objects as the value response, the client instance sends an array of objects as the value
of the access_token parameter. Each object MUST conform to the of the access_token parameter. Each object MUST conform to the
request format for a single access token request, as specified in request format for a single access token request, as specified in
requesting a single access token (Section 2.1.1). Additionally, each Section 2.1.1. Additionally, each object in the array MUST include
object in the array MUST include the label field, and all values of the label field, and all values of these fields MUST be unique within
these fields MUST be unique within the request. If the client the request. If the client instance does not include a label value
instance does not include a label value for any entry in the array, for any entry in the array or the values of the label field are not
or the values of the label field are not unique within the array, the unique within the array, the AS MUST return an "invalid_request"
AS MUST return an "invalid_request" error (Section 3.6). error (Section 3.6).
The following non-normative example shows a request for two separate The following non-normative example shows a request for two separate
access tokens, token1 and token2. access tokens: token1 and token2.
"access_token": [ "access_token": [
{ {
"label": "token1", "label": "token1",
"access": [ "access": [
{ {
"type": "photo-api", "type": "photo-api",
"actions": [ "actions": [
"read", "read",
"write", "write",
skipping to change at page 41, line 4 skipping to change at line 1754
"datatypes": [ "datatypes": [
"data", "data",
"pictures", "pictures",
"walrus whiskers" "walrus whiskers"
] ]
} }
], ],
"flags": [ "bearer" ] "flags": [ "bearer" ]
} }
] ]
All approved access requests are returned in the multiple access All approved access requests are returned in the multiple access
token response (Section 3.2.2) structure using the values of the tokens response structure (Section 3.2.2) using the values of the
label fields in the request. label fields in the request.
2.2. Requesting Subject Information 2.2. Requesting Subject Information
If the client instance is requesting information about the RO from If the client instance is requesting information about the RO from
the AS, it sends a subject field as a JSON object. This object MAY the AS, it sends a subject field as a JSON object. This object MAY
contain the following fields. contain the following fields.
sub_id_formats (array of strings): An array of subject identifier sub_id_formats (array of strings): An array of subject identifier
subject formats requested for the RO, as defined by [RFC9493]. subject formats requested for the RO, as defined by [RFC9493].
REQUIRED if subject identifiers are requested. REQUIRED if subject identifiers are requested.
assertion_formats (array of strings): An array of requested assertion_formats (array of strings): An array of requested
assertion formats. Possible values include id_token for an OpenID assertion formats. Possible values include id_token for an OpenID
Connect ID Token ([OIDC]) and saml2 for a SAML 2 assertion Connect ID Token [OIDC] and saml2 for a Security Assertion Markup
([SAML2]). Additional assertion formats are defined by the GNAP Language (SAML) 2 assertion [SAML2]. Additional assertion formats
Assertion Formats Registry (Section 11.6). REQUIRED if assertions can be defined in the "GNAP Assertion Formats" registry
are requested. (Section 10.6). REQUIRED if assertions are requested.
sub_ids (array of objects): An array of subject identifiers sub_ids (array of objects): An array of subject identifiers
representing the subject for which information is being requested. representing the subject for which information is being requested.
Each object is a subject identifier as defined by [RFC9493]. All Each object is a subject identifier as defined by [RFC9493]. All
identifiers in the sub_ids array MUST identify the same subject. identifiers in the sub_ids array MUST identify the same subject.
If omitted, the AS SHOULD assume that subject information requests If omitted, the AS SHOULD assume that subject information requests
are about the current user and SHOULD require direct interaction are about the current user and SHOULD require direct interaction
or proof of presence before releasing information. OPTIONAL. or proof of presence before releasing information. OPTIONAL.
Additional fields are defined in the GNAP Subject Information Request Additional fields can be defined in the "GNAP Subject Information
Fields Registry (Section 11.5). Request Fields" registry (Section 10.5).
"subject": { "subject": {
"sub_id_formats": [ "iss_sub", "opaque" ], "sub_id_formats": [ "iss_sub", "opaque" ],
"assertion_formats": [ "id_token", "saml2" ] "assertion_formats": [ "id_token", "saml2" ]
} }
The AS can determine the RO's identity and permission for releasing The AS can determine the RO's identity and permission for releasing
this information through interaction with the RO (Section 4), AS this information through interaction with the RO (Section 4), AS
policies, or assertions presented by the client instance policies, or assertions presented by the client instance
(Section 2.4). If this is determined positively, the AS MAY return (Section 2.4). If this is determined positively, the AS MAY return
the RO's information in its response (Section 3.4) as requested. the RO's information in its response (Section 3.4) as requested.
Subject identifier types requested by the client instance serve only Subject identifier types requested by the client instance serve only
to identify the RO in the context of the AS and can't be used as to identify the RO in the context of the AS and can't be used as
communication channels by the client instance, as discussed in communication channels by the client instance, as discussed in
Section 3.4. Section 3.4.
2.3. Identifying the Client Instance 2.3. Identifying the Client Instance
When sending new grant request to the AS, the client instance MUST When sending a new grant request to the AS, the client instance MUST
identify itself by including its client information in the client identify itself by including its client information in the client
field of the request and by signing the request with its unique key field of the request and by signing the request with its unique key
as described in Section 7.3. Note that once a grant has been created as described in Section 7.3. Note that once a grant has been created
and is in the _pending_ or _accepted_ states, the AS can determine and is in either the _pending_ or the _accepted_ state, the AS can
which client is associated with the grant by dereferencing the determine which client is associated with the grant by dereferencing
continuation access token sent in the continuation request the continuation access token sent in the continuation request
(Section 5). As a consequence, the client field is not sent or (Section 5). As a consequence, the client field is not sent or
accepted for continuation requests. accepted for continuation requests.
Client information is sent by value as an object or by reference as a Client information is sent by value as an object or by reference as a
string (see Section 2.3.1). string (see Section 2.3.1).
When client instance information is sent by value, the client field When client instance information is sent by value, the client field
of the request consists of a JSON object with the following fields. of the request consists of a JSON object with the following fields.
key (object / string): The public key of the client instance to be key (object / string): The public key of the client instance to be
used in this request as described in Section 7.1 or a reference to used in this request as described in Section 7.1 or a reference to
a key as described in Section 7.1.1. REQUIRED. a key as described in Section 7.1.1. REQUIRED.
class_id (string): An identifier string that the AS can use to class_id (string): An identifier string that the AS can use to
identify the client software comprising this client instance. The identify the client software comprising this client instance. The
contents and format of this field are up to the AS. OPTIONAL. contents and format of this field are up to the AS. OPTIONAL.
display (object): An object containing additional information that display (object): An object containing additional information that
the AS MAY display to the RO during interaction, authorization, the AS MAY display to the RO during interaction, authorization,
and management. OPTIONAL. (Section 2.3.2) and management. OPTIONAL. See Section 2.3.2.
"client": { "client": {
"key": { "key": {
"proof": "httpsig", "proof": "httpsig",
"jwk": { "jwk": {
"kty": "RSA", "kty": "RSA",
"e": "AQAB", "e": "AQAB",
"kid": "xyz-1", "kid": "xyz-1",
"alg": "RS256", "alg": "RS256",
"n": "kOB5rR4Jv0GMeLaY6_It_r3ORwdf8ci_JtffXyaSx8..." "n": "kOB5rR4Jv0GMeLaY6_It_r3ORwdf8ci_JtffXyaSx8..."
} }
}, },
"class_id": "web-server-1234", "class_id": "web-server-1234",
"display": { "display": {
"name": "My Client Display Name", "name": "My Client Display Name",
"uri": "https://example.net/client" "uri": "https://example.net/client"
} }
} }
Additional fields are defined in the GNAP Client Instance Fields
Registry (Section 11.7). Additional fields can be defined in the "GNAP Client Instance Fields"
registry (Section 10.7).
Absent additional attestations, profiles, or trust mechanisms, both Absent additional attestations, profiles, or trust mechanisms, both
the display and class_id fields are self-declarative, presented by the display and class_id fields are self-declarative, presented by
the client instance. The AS needs to exercise caution in their the client instance. The AS needs to exercise caution in their
interpretation, taking them as a hint but not as absolute truth. The interpretation, taking them as a hint but not as absolute truth. The
class_id field can be used in a variety of ways to help the AS make class_id field can be used in a variety of ways to help the AS make
sense of the particular context in which the client instance is sense of the particular context in which the client instance is
operating. In corporate environments, for example, different levels operating. In corporate environments, for example, different levels
of trust might apply depending on security policies. This field aims of trust might apply depending on security policies. This field aims
to help the AS adjust its own access decisions for different classes to help the AS adjust its own access decisions for different classes
of client software. It is possible to configure a set of values and of client software. It is possible to configure a set of values and
rules during a pre-registration, and then have the client instances rules during a pre-registration and then have the client instances
provide them later in runtime as a hint to the AS. In other cases, provide them later in runtime as a hint to the AS. In other cases,
the client runs with a specific AS in mind, so a single hardcoded the client runs with a specific AS in mind, so a single hardcoded
value would acceptable (for instance, a set top box with a class_id value would be acceptable (for instance, a set-top box with a
claiming to be "FooBarTV version 4"). While the client instance may class_id claiming to be "FooBarTV version 4"). While the client
not have contacted the AS yet, the value of this class_id field can instance may not have contacted the AS yet, the value of this
be evaluated by the AS according to a broader context of dynamic use, class_id field can be evaluated by the AS according to a broader
alongside other related information available elsewhere (for context of dynamic use, alongside other related information available
instance, corresponding fields in a certificate). If the AS is not elsewhere (for instance, corresponding fields in a certificate). If
able to interpret or validate the class_id field, it MUST either the AS is not able to interpret or validate the class_id field, it
return an invalid_client error (Section 3.6) or interpret the request MUST either return an invalid_client error (Section 3.6) or interpret
as if the class_id were not present. See additional discussion of the request as if the class_id were not present. See additional
client instance impersonation in Section 13.15. discussion of client instance impersonation in Section 11.15.
The client instance MUST prove possession of any presented key by the The client instance MUST prove possession of any presented key by the
proof mechanism associated with the key in the request. Key proofing proof mechanism associated with the key in the request. Key proofing
methods are defined in the GNAP Key Proofing Methods Registry methods are defined in the "GNAP Key Proofing Methods" registry
(Section 11.16) and an initial set of methods is described in (Section 10.16), and an initial set of methods is described in
Section 7.3. Section 7.3.
If the same public key is sent by value on different access requests, If the same public key is sent by value on different access requests,
the AS MUST treat these requests as coming from the same client the AS MUST treat these requests as coming from the same client
instance for purposes of identification, authentication, and policy instance for purposes of identification, authentication, and policy
application. application.
If the AS does not know the client instance's public key ahead of If the AS does not know the client instance's public key ahead of
time, the AS can choose how to process the unknown key. Common time, the AS can choose how to process the unknown key. Common
approaches include: approaches include:
skipping to change at page 44, line 11 skipping to change at line 1905
* Limiting the client's requested access to only certain APIs and * Limiting the client's requested access to only certain APIs and
information information
* Denying the request entirely by returning an invalid_client error * Denying the request entirely by returning an invalid_client error
(Section 3.6) (Section 3.6)
The client instance MUST NOT send a symmetric key by value in the key The client instance MUST NOT send a symmetric key by value in the key
field of the request, as doing so would expose the key directly field of the request, as doing so would expose the key directly
instead of simply proving possession of it. See considerations on instead of simply proving possession of it. See considerations on
symmetric keys in Section 13.7. To use symmetric keys, the client symmetric keys in Section 11.7. To use symmetric keys, the client
instance can send the key by reference (Section 7.1.1) or send the instance can send the key by reference (Section 7.1.1) or send the
entire client identity by reference (Section 2.3.1). entire client identity by reference (Section 2.3.1).
The client instance's key can be pre-registered with the AS ahead of The client instance's key can be pre-registered with the AS ahead of
time and associated with a set of policies and allowable actions time and associated with a set of policies and allowable actions
pertaining to that client. If this pre-registration includes other pertaining to that client. If this pre-registration includes other
fields that can occur in the client request object described in this fields that can occur in the client request object described in this
section, such as class_id or display, the pre-registered values MUST section, such as class_id or display, the pre-registered values MUST
take precedence over any values given at runtime. Additional fields take precedence over any values given at runtime. Additional fields
sent during a request but not present in a pre-registered client sent during a request but not present in a pre-registered client
instance record at the AS SHOULD NOT be added to the client's pre- instance record at the AS SHOULD NOT be added to the client's pre-
registered record. See additional considerations regarding client registered record. See additional considerations regarding client
instance impersonation in Section 13.15. instance impersonation in Section 11.15.
A client instance that is capable of talking to multiple AS's SHOULD A client instance that is capable of talking to multiple ASes SHOULD
use a different key for each AS to prevent a class of mix-up attacks use a different key for each AS to prevent a class of mix-up attacks
as described in Section 13.31 unless other mechanisms can be used to as described in Section 11.31, unless other mechanisms can be used to
assure the identity of the AS for a given request. assure the identity of the AS for a given request.
2.3.1. Identifying the Client Instance by Reference 2.3.1. Identifying the Client Instance by Reference
If the client instance has an instance identifier that the AS can use If the client instance has an instance identifier that the AS can use
to determine appropriate key information, the client instance can to determine appropriate key information, the client instance can
send this instance identifier as a direct reference value in lieu of send this instance identifier as a direct reference value in lieu of
the client object. The instance identifier MAY be assigned to a the client object. The instance identifier MAY be assigned to a
client instance at runtime through a grant response (Section 3.5) or client instance at runtime through a grant response (Section 3.5) or
MAY be obtained in another fashion, such as a static registration MAY be obtained in another fashion, such as a static registration
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If the client instance has additional information to display to the If the client instance has additional information to display to the
RO during any interactions at the AS, it MAY send that information in RO during any interactions at the AS, it MAY send that information in
the "display" field. This field is a JSON object that declares the "display" field. This field is a JSON object that declares
information to present to the RO during any interactive sequences. information to present to the RO during any interactive sequences.
name (string): Display name of the client software. RECOMMENDED. name (string): Display name of the client software. RECOMMENDED.
uri (string): User-facing information about the client software, uri (string): User-facing information about the client software,
such as a web page. This URI MUST be an absolute URI. OPTIONAL. such as a web page. This URI MUST be an absolute URI. OPTIONAL.
logo_uri (string) Display image to represent the client software. logo_uri (string): Display image to represent the client software.
This URI MUST be an absolute URI. The logo MAY be passed by value This URI MUST be an absolute URI. The logo MAY be passed by value
by using a data: URI [RFC2397] referencing an image mediatype. by using a data: URI [RFC2397] referencing an image media type.
OPTIONAL. OPTIONAL.
"display": { "display": {
"name": "My Client Display Name", "name": "My Client Display Name",
"uri": "https://example.net/client", "uri": "https://example.net/client",
"logo_uri": "data:image/png;base64,Eeww...=" "logo_uri": "data:image/png;base64,Eeww...="
} }
Additional display fields are defined by the GNAP Client Instance Additional display fields can be defined in the "GNAP Client Instance
Display Fields Registry (Section 11.8). Display Fields" registry (Section 10.8).
The AS SHOULD use these values during interaction with the RO. The The AS SHOULD use these values during interaction with the RO. The
values are for informational purposes only and MUST NOT be taken as values are for informational purposes only and MUST NOT be taken as
authentic proof of the client instance's identity or source. The AS authentic proof of the client instance's identity or source. The AS
MAY restrict display values to specific client instances, as MAY restrict display values to specific client instances, as
identified by their keys in Section 2.3. See additional identified by their keys in Section 2.3. See additional
considerations for displayed client information in Section 13.15 and considerations for displayed client information in Section 11.15 and
for the logo_uri in particular in Section 13.16. for the logo_uri in particular in Section 11.16.
2.3.3. Authenticating the Client Instance 2.3.3. Authenticating the Client Instance
If the presented key is known to the AS and is associated with a If the presented key is known to the AS and is associated with a
single instance of the client software, the process of presenting a single instance of the client software, the process of presenting a
key and proving possession of that key is sufficient to authenticate key and proving possession of that key is sufficient to authenticate
the client instance to the AS. The AS MAY associate policies with the client instance to the AS. The AS MAY associate policies with
the client instance identified by this key, such as limiting which the client instance identified by this key, such as limiting which
resources can be requested and which interaction methods can be used. resources can be requested and which interaction methods can be used.
For example, only specific client instances with certain known keys For example, only specific client instances with certain known keys
might be trusted with access tokens without the AS interacting might be trusted with access tokens without the AS interacting
directly with the RO as in Appendix C.3. directly with the RO, as in Appendix B.3.
The presentation of a key allows the AS to strongly associate The presentation of a key allows the AS to strongly associate
multiple successive requests from the same client instance with each multiple successive requests from the same client instance with each
other. This is true when the AS knows the key ahead of time and can other. This is true when the AS knows the key ahead of time and can
use the key to authenticate the client instance, but also if the key use the key to authenticate the client instance, but it is also true
is ephemeral and created just for this series of requests. As such if the key is ephemeral and created just for this series of requests.
the AS MAY allow for client instances to make requests with unknown As such, the AS MAY allow for client instances to make requests with
keys. This pattern allows for ephemeral client instances, such as unknown keys. This pattern allows for ephemeral client instances
single-page applications, and client software with many individual (such as single-page applications) and client software with many
long-lived instances, such as mobile applications, to generate key individual long-lived instances (such as mobile applications) to
pairs per instance and use the keys within the protocol without generate key pairs per instance and use the keys within the protocol
having to go through a separate registration step. The AS MAY limit without having to go through a separate registration step. The AS
which capabilities are made available to client instances with MAY limit which capabilities are made available to client instances
unknown keys. For example, the AS could have a policy saying that with unknown keys. For example, the AS could have a policy saying
only previously-registered client instances can request particular that only previously registered client instances can request
resources, or that all client instances with unknown keys have to be particular resources or that all client instances with unknown keys
interactively approved by an RO. have to be interactively approved by an RO.
2.4. Identifying the User 2.4. Identifying the User
If the client instance knows the identity of the end user through one If the client instance knows the identity of the end user through one
or more identifiers or assertions, the client instance MAY send that or more identifiers or assertions, the client instance MAY send that
information to the AS in the "user" field. The client instance MAY information to the AS in the "user" field. The client instance MAY
pass this information by value or by reference (See Section 2.4.1). pass this information by value or by reference (see Section 2.4.1).
sub_ids (array of objects): An array of subject identifiers for the sub_ids (array of objects): An array of subject identifiers for the
end user, as defined by [RFC9493]. OPTIONAL. end user, as defined by [RFC9493]. OPTIONAL.
assertions (array of objects) An array containing assertions as assertions (array of objects): An array containing assertions as
objects each containing the assertion format and the assertion objects, each containing the assertion format and the assertion
value as the JSON string serialization of the assertion, as value as the JSON string serialization of the assertion, as
defined in Section 3.4. OPTIONAL. defined in Section 3.4. OPTIONAL.
"user": { "user": {
"sub_ids": [ { "sub_ids": [ {
"format": "opaque", "format": "opaque",
"id": "J2G8G8O4AZ" "id": "J2G8G8O4AZ"
} ], } ],
"assertions": [ { "assertions": [ {
"format": "id_token", "format": "id_token",
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of this specification, common validation steps include verifying the of this specification, common validation steps include verifying the
signature of the assertion against a trusted signing key, verifying signature of the assertion against a trusted signing key, verifying
the audience and issuer of the assertion map to expected values, and the audience and issuer of the assertion map to expected values, and
verifying the time window for the assertion itself. However, note verifying the time window for the assertion itself. However, note
that in many use cases, some of these common steps are relaxed. For that in many use cases, some of these common steps are relaxed. For
example, an AS acting as an identity provider (IdP) could expect that example, an AS acting as an identity provider (IdP) could expect that
assertions being presented using this mechanism were issued by the AS assertions being presented using this mechanism were issued by the AS
to the client software. The AS would verify that the AS is the to the client software. The AS would verify that the AS is the
issuer of the assertion, not the audience, and that the client issuer of the assertion, not the audience, and that the client
instance is instead the audience of the assertion. Similarly, an AS instance is instead the audience of the assertion. Similarly, an AS
might accept a recently-expired assertion in order to help bootstrap might accept a recently expired assertion in order to help bootstrap
a new session with a specific end user. a new session with a specific end user.
If the identified end user does not match the RO present at the AS If the identified end user does not match the RO present at the AS
during an interaction step, and the AS is not explicitly allowing a during an interaction step and the AS is not explicitly allowing a
cross-user authorization, the AS SHOULD reject the request with an cross-user authorization, the AS SHOULD reject the request with an
unknown_user error (Section 3.6). unknown_user error (Section 3.6).
If the AS trusts the client instance to present verifiable assertions If the AS trusts the client instance to present verifiable assertions
or known subject identifiers, such as an opaque identifier issued by or known subject identifiers, such as an opaque identifier issued by
the AS for this specific client instance, the AS MAY decide, based on the AS for this specific client instance, the AS MAY decide, based on
its policy, to skip interaction with the RO, even if the client its policy, to skip interaction with the RO, even if the client
instance provides one or more interaction modes in its request. instance provides one or more interaction modes in its request.
See Section 13.30 for considerations that the AS has to make when See Section 11.30 for considerations for the AS when accepting and
accepting and processing assertions from the client instance. processing assertions from the client instance.
2.4.1. Identifying the User by Reference 2.4.1. Identifying the User by Reference
The AS can identify the current end user to the client instance with The AS can identify the current end user to the client instance with
a reference which can be used by the client instance to refer to the a reference that can be used by the client instance to refer to the
end user across multiple requests. If the client instance has a end user across multiple requests. If the client instance has a
reference for the end user at this AS, the client instance MAY pass reference for the end user at this AS, the client instance MAY pass
that reference as a string. The format of this string is opaque to that reference as a string. The format of this string is opaque to
the client instance. the client instance.
"user": "XUT2MFM1XBIKJKSDU8QM" "user": "XUT2MFM1XBIKJKSDU8QM"
One means of dynamically obtaining such a user reference is from the One means of dynamically obtaining such a user reference is from the
AS returning an opaque subject identifier as described in AS returning an opaque subject identifier as described in
Section 3.4. Other means of configuring a client instance with a Section 3.4. Other means of configuring a client instance with a
user identifier are out of scope of this specification. The lifetime user identifier are out of scope of this specification. The lifetime
and validity of these user references is determined by the AS and and validity of these user references are determined by the AS, and
this lifetime is not exposed to the client instance in GNAP. As this lifetime is not exposed to the client instance in GNAP. As
such, a client instance using such a user reference is likely to keep such, a client instance using such a user reference is likely to keep
using that reference until such a time as it stops working. using that reference until it stops working.
User reference identifiers are not intended to be human-readable user User reference identifiers are not intended to be human-readable user
identifiers or structured assertions. For the client instance to identifiers or structured assertions. For the client instance to
send either of these, the client can use the full user request object send either of these, the client can use the full user request object
(Section 2.4) instead. (Section 2.4) instead.
If the AS does not recognize the user reference, it MUST return an If the AS does not recognize the user reference, it MUST return an
unknown_user error (Section 3.6). unknown_user error (Section 3.6).
2.5. Interacting with the User 2.5. Interacting with the User
Often, the AS will require interaction with the RO (Section 4) in Often, the AS will require interaction with the RO (Section 4) in
order to approve a requested delegation to the client instance for order to approve a requested delegation to the client instance for
both access to resources and direct subject information. Many times both access to resources and direct subject information. Many times,
the end user using the client instance is the same person as the RO, the end user using the client instance is the same person as the RO,
and the client instance can directly drive interaction with the end and the client instance can directly drive interaction with the end
user by facilitating the process through means such as redirection to user by facilitating the process through means such as redirection to
a URI or launching an application. Other times, the client instance a URI or launching an application. Other times, the client instance
can provide information to start the RO's interaction on a secondary can provide information to start the RO's interaction on a secondary
device, or the client instance will wait for the RO to approve the device, or the client instance will wait for the RO to approve the
request asynchronously. The client instance could also be signaled request asynchronously. The client instance could also be signaled
that interaction has concluded through a callback mechanism. that interaction has concluded through a callback mechanism.
The client instance declares the parameters for interaction methods The client instance declares the parameters for interaction methods
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declare how the client can initiate and complete the request, as well declare how the client can initiate and complete the request, as well
as provide hints to the AS about user preferences such as locale. A as provide hints to the AS about user preferences such as locale. A
client instance MUST NOT declare an interaction mode it does not client instance MUST NOT declare an interaction mode it does not
support. The client instance MAY send multiple modes in the same support. The client instance MAY send multiple modes in the same
request. There is no preference order specified in this request. An request. There is no preference order specified in this request. An
AS MAY respond to any, all, or none of the presented interaction AS MAY respond to any, all, or none of the presented interaction
modes (Section 3.3) in a request, depending on its capabilities and modes (Section 3.3) in a request, depending on its capabilities and
what is allowed to fulfill the request. what is allowed to fulfill the request.
start (array of objects/strings): Indicates how the client instance start (array of objects/strings): Indicates how the client instance
can start an interaction. REQUIRED. (Section 2.5.1) can start an interaction. REQUIRED. See Section 2.5.1.
finish (object): Indicates how the client instance can receive an finish (object): Indicates how the client instance can receive an
indication that interaction has finished at the AS. OPTIONAL. indication that interaction has finished at the AS. OPTIONAL.
(Section 2.5.2) See Section 2.5.2.
hints (object): Provides additional information to inform the hints (object): Provides additional information to inform the
interaction process at the AS. OPTIONAL. (Section 2.5.3) interaction process at the AS. OPTIONAL. See Section 2.5.3.
In the following non-normative example, the client instance is In the following non-normative example, the client instance is
indicating that it can redirect (Section 2.5.1.1) the end user to an indicating that it can redirect (Section 2.5.1.1) the end user to an
arbitrary URI and can receive a redirect (Section 2.5.2.1) through a arbitrary URI and can receive a redirect (Section 2.5.2.1) through a
browser request. Note that the client instance does not accept a browser request. Note that the client instance does not accept a
push-style callback. The pattern of using a redirect for both push-style callback. The pattern of using a redirect for both
interaction start and finish is common for web-based client software. interaction start and finish is common for web-based client software.
"interact": { "interact": {
"start": ["redirect"], "start": ["redirect"],
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"method": "redirect", "method": "redirect",
"uri": "https://client.example.net/return/123455", "uri": "https://client.example.net/return/123455",
"nonce": "LKLTI25DK82FX4T4QFZC" "nonce": "LKLTI25DK82FX4T4QFZC"
} }
} }
In the following non-normative example, the client instance is In the following non-normative example, the client instance is
indicating that it can display a user code (Section 2.5.1.3) and indicating that it can display a user code (Section 2.5.1.3) and
direct the end user to an arbitrary URI (Section 2.5.1.1), but it direct the end user to an arbitrary URI (Section 2.5.1.1), but it
cannot accept a redirect or push callback. This pattern is common cannot accept a redirect or push callback. This pattern is common
for devices with robust display capabilities but that expect the use for devices that have robust display capabilities but expect the use
of a secondary device to facilitate end-user interaction with the AS, of a secondary device to facilitate end-user interaction with the AS,
such as a set-top box capable of displaying an interaction URL as a such as a set-top box capable of displaying an interaction URL as a
QR code. QR code.
"interact": { "interact": {
"start": ["redirect", "user_code"] "start": ["redirect", "user_code"]
} }
In the following non-normative example, the client instance is In the following non-normative example, the client instance is
indicating that it can not start any interaction with the end-user, indicating that it cannot start any interaction with the end user but
but that the AS can push an interaction finish message that the AS can push an interaction finish message (Section 2.5.2.2)
(Section 2.5.2.2) when authorization from the RO is received when authorization from the RO is received asynchronously. This
asynchronously. This pattern is common for scenarios where a service pattern is common for scenarios where a service needs to be
needs to be authorized, but the RO is able to be contacted separately authorized, but the RO is able to be contacted separately from the
from the GNAP transaction itself, such as through a push notification GNAP transaction itself, such as through a push notification or
or existing interactive session on a secondary device. existing interactive session on a secondary device.
"interact": { "interact": {
"start": [], "start": [],
"finish": { "finish": {
"method": "push", "method": "push",
"uri": "https://client.example.net/return/123455", "uri": "https://client.example.net/return/123455",
"nonce": "LKLTI25DK82FX4T4QFZC" "nonce": "LKLTI25DK82FX4T4QFZC"
} }
} }
If the client instance does not provide a suitable interaction If the client instance does not provide a suitable interaction
mechanism, the AS cannot contact the RO asynchronously, and the AS mechanism, the AS cannot contact the RO asynchronously, and the AS
determines that interaction is required, then the AS MUST return an determines that interaction is required, then the AS MUST return an
invalid_interaction error (Section 3.6) since the client instance invalid_interaction error (Section 3.6) since the client instance
will be unable to complete the request without authorization. will be unable to complete the request without authorization.
2.5.1. Start Mode Definitions 2.5.1. Start Mode Definitions
If the client instance is capable of starting interaction with the If the client instance is capable of starting interaction with the
end user, the client instance indicates this by sending an array of end user, the client instance indicates this by sending an array of
start modes under the start key. Each interaction start modes has a start modes under the start key. Each interaction start mode has a
unique identifying name. Interaction start modes are specified in unique identifying name. Interaction start modes are specified in
the array either by a string, which consists of the start mode name the array either by a string, which consists of the start mode name
on its own, or by a JSON object with the required field mode: on its own, or by a JSON object with the required field mode:
mode: The interaction start mode. REQUIRED. mode: The interaction start mode. REQUIRED.
Interaction start modes defined as objects MAY define additional Interaction start modes defined as objects MAY define additional
parameters to be required in the object. parameters to be required in the object.
The start array can contain both string-type and object-type modes. The start array can contain both string-type and object-type modes.
This specification defines the following interaction start modes: This specification defines the following interaction start modes:
"redirect" (string): Indicates that the client instance can direct "redirect" (string): Indicates that the client instance can direct
the end user to an arbitrary URI for interaction. Section 2.5.1.1 the end user to an arbitrary URI for interaction. See
Section 2.5.1.1.
"app" (string): Indicates that the client instance can launch an "app" (string): Indicates that the client instance can launch an
application on the end user's device for interaction. application on the end user's device for interaction. See
Section 2.5.1.2 Section 2.5.1.2.
"user_code" (string): Indicates that the client instance can "user_code" (string): Indicates that the client instance can
communicate a human-readable short code to the end user for use communicate a short, human-readable code to the end user for use
with a stable URI. Section 2.5.1.3 with a stable URI. See Section 2.5.1.3.
"user_code_uri" (string): Indicates that the client instance can "user_code_uri" (string): Indicates that the client instance can
communicate a human-readable short code to the end user for use communicate a short, human-readable code to the end user for use
with a short, dynamic URI. Section 2.5.1.4 with a short, dynamic URI. See Section 2.5.1.4.
Additional start modes are defined in the GNAP Interaction Start Additional start modes can be defined in the "GNAP Interaction Start
Modes Registry (Section 11.9). Modes" registry (Section 10.9).
2.5.1.1. Redirect to an Arbitrary URI 2.5.1.1. Redirect to an Arbitrary URI
If the client instance is capable of directing the end user to a URI If the client instance is capable of directing the end user to a URI
defined by the AS at runtime, the client instance indicates this by defined by the AS at runtime, the client instance indicates this by
including redirect in the array under the start key. The means by including redirect in the array under the start key. The means by
which the client instance will activate this URI is out of scope of which the client instance will activate this URI are out of scope of
this specification, but common methods include an HTTP redirect, this specification, but common methods include an HTTP redirect,
launching a browser on the end user's device, providing a scannable launching a browser on the end user's device, providing a scannable
image encoding, and printing out a URI to an interactive console. image encoding, and printing out a URI to an interactive console.
While this URI is generally hosted at the AS, the client instance can While this URI is generally hosted at the AS, the client instance can
make no assumptions about its contents, composition, or relationship make no assumptions about its contents, composition, or relationship
to the grant endpoint URI. to the grant endpoint URI.
"interact": { "interact": {
"start": ["redirect"] "start": ["redirect"]
} }
If this interaction mode is supported for this client instance and If this interaction mode is supported for this client instance and
request, the AS returns a redirect interaction response request, the AS returns a redirect interaction response
Section 3.3.1. The client instance manages this interaction method (Section 3.3.1). The client instance manages this interaction method
as described in Section 4.1.1. as described in Section 4.1.1.
See Section 13.29 for more considerations regarding the use of front- See Section 11.29 for more considerations regarding the use of front-
channel communication techniques. channel communication techniques.
2.5.1.2. Open an Application-specific URI 2.5.1.2. Open an Application-Specific URI
If the client instance can open a URI associated with an application If the client instance can open a URI associated with an application
on the end user's device, the client instance indicates this by on the end user's device, the client instance indicates this by
including app in the array under the start key. The means by which including app in the array under the start key. The means by which
the client instance determines the application to open with this URI the client instance determines the application to open with this URI
are out of scope of this specification. are out of scope of this specification.
"interact": { "interact": {
"start": ["app"] "start": ["app"]
} }
skipping to change at page 52, line 12 skipping to change at line 2270
payload (Section 3.3.2). The client instance manages this payload (Section 3.3.2). The client instance manages this
interaction method as described in Section 4.1.4. interaction method as described in Section 4.1.4.
2.5.1.3. Display a Short User Code 2.5.1.3. Display a Short User Code
If the client instance is capable of displaying or otherwise If the client instance is capable of displaying or otherwise
communicating a short, human-entered code to the RO, the client communicating a short, human-entered code to the RO, the client
instance indicates this by including user_code in the array under the instance indicates this by including user_code in the array under the
start key. This code is to be entered at a static URI that does not start key. This code is to be entered at a static URI that does not
change at runtime. The client instance has no reasonable means to change at runtime. The client instance has no reasonable means to
communicate a dynamic URI to the RO, and so this URI is usually communicate a dynamic URI to the RO, so this URI is usually
communicated out of band to the RO through documentation or other communicated out of band to the RO through documentation or other
messaging outside of GNAP. While this URI is generally hosted at the messaging outside of GNAP. While this URI is generally hosted at the
AS, the client instance can make no assumptions about its contents, AS, the client instance can make no assumptions about its contents,
composition, or relationship to the grant endpoint URI. composition, or relationship to the grant endpoint URI.
"interact": { "interact": {
"start": ["user_code"] "start": ["user_code"]
} }
If this interaction mode is supported for this client instance and If this interaction mode is supported for this client instance and
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If the client instance is capable of receiving a message from the AS If the client instance is capable of receiving a message from the AS
indicating that the RO has completed their interaction, the client indicating that the RO has completed their interaction, the client
instance indicates this by sending the following members of an object instance indicates this by sending the following members of an object
under the finish key. under the finish key.
method (string): The callback method that the AS will use to contact method (string): The callback method that the AS will use to contact
the client instance. REQUIRED. the client instance. REQUIRED.
uri (string): Indicates the URI that the AS will either send the RO uri (string): Indicates the URI that the AS will either send the RO
to after interaction or send an HTTP POST request. This URI MAY to after interaction or send an HTTP POST request. This URI MAY
be unique per request and MUST be hosted by or accessible by the be unique per request and MUST be hosted by or accessible to the
client instance. This URI MUST be an absolute URI, and MUST NOT client instance. This URI MUST be an absolute URI and MUST NOT
contain any fragment component. If the client instance needs any contain any fragment component. If the client instance needs any
state information to tie to the front channel interaction state information to tie to the front-channel interaction
response, it MUST use a unique callback URI to link to that response, it MUST use a unique callback URI to link to that
ongoing state. The allowable URIs and URI patterns MAY be ongoing state. The allowable URIs and URI patterns MAY be
restricted by the AS based on the client instance's presented key restricted by the AS based on the client instance's presented key
information. The callback URI SHOULD be presented to the RO information. The callback URI SHOULD be presented to the RO
during the interaction phase before redirect. REQUIRED for during the interaction phase before redirect. REQUIRED for
redirect and push methods. redirect and push methods.
nonce (string): Unique ASCII string value to be used in the nonce (string): Unique ASCII string value to be used in the
calculation of the "hash" query parameter sent to the callback calculation of the "hash" query parameter sent to the callback
URI, must be sufficiently random to be unguessable by an attacker. URI. It must be sufficiently random to be unguessable by an
MUST be generated by the client instance as a unique value for attacker. It MUST be generated by the client instance as a unique
this request. REQUIRED. value for this request. REQUIRED.
hash_method (string): An identifier of a hash calculation mechanism hash_method (string): An identifier of a hash calculation mechanism
to be used for the callback hash in Section 4.2.3, as defined in to be used for the callback hash in Section 4.2.3, as defined in
the IANA Named Information Hash Algorithm Registry [HASH-ALG]. If the IANA "Named Information Hash Algorithm Registry" [HASH-ALG].
absent, the default value is sha-256. OPTIONAL. If absent, the default value is sha-256. OPTIONAL.
This specification defines the following values for the method This specification defines the following values for the method
parameter, with other values defined by the GNAP Interaction Finish parameter; additional values can be defined in the "GNAP Interaction
Methods Registry (Section 11.10): Finish Methods" registry (Section 10.10):
"redirect": Indicates that the client instance can receive a "redirect": Indicates that the client instance can receive a
redirect from the end user's device after interaction with the RO redirect from the end user's device after interaction with the RO
has concluded. Section 2.5.2.1 has concluded. See Section 2.5.2.1.
"push": Indicates that the client instance can receive an HTTP POST "push": Indicates that the client instance can receive an HTTP POST
request from the AS after interaction with the RO has concluded. request from the AS after interaction with the RO has concluded.
Section 2.5.2.2 See Section 2.5.2.2.
If interaction finishing is supported for this client instance and If interaction finishing is supported for this client instance and
request, the AS will return a nonce (Section 3.3.5) used by the request, the AS will return a nonce (Section 3.3.5) used by the
client instance to validate the callback. All interaction finish client instance to validate the callback. All interaction finish
methods MUST use this nonce to allow the client to verify the methods MUST use this nonce to allow the client to verify the
connection between the pending interaction request and the callback. connection between the pending interaction request and the callback.
GNAP does this through the use of the interaction hash, defined in GNAP does this through the use of the interaction hash, defined in
Section 4.2.3. All requests to the callback URI MUST be processed as Section 4.2.3. All requests to the callback URI MUST be processed as
described in Section 4.2. described in Section 4.2.
All interaction finish methods MUST require presentation of an All interaction finish methods MUST require presentation of an
interaction reference for continuing this grant request. This means interaction reference for continuing this grant request. This means
that the interaction reference MUST be returned by the AS and MUST be that the interaction reference MUST be returned by the AS and MUST be
presented by the client as described in Section 5.1. The means by presented by the client as described in Section 5.1. The means by
which the interaction reference is returned to the client instance is which the interaction reference is returned to the client instance
specific to the interaction finish method. are specific to the interaction finish method.
2.5.2.1. Receive an HTTP Callback Through the Browser 2.5.2.1. Receive an HTTP Callback through the Browser
A finish method value of redirect indicates that the client instance A finish method value of redirect indicates that the client instance
will expect a request from the RO's browser using the HTTP method GET will expect a request from the RO's browser using the HTTP method GET
as described in Section 4.2.1. as described in Section 4.2.1.
The client instance's URI MUST be protected by HTTPS, be hosted on a The client instance's URI MUST be protected by HTTPS, be hosted on a
server local to the RO's browser ("localhost"), or use an server local to the RO's browser ("localhost"), or use an
application-specific URI scheme that is loaded on the end user's application-specific URI scheme that is loaded on the end user's
device. device.
skipping to change at page 54, line 36 skipping to change at line 2391
"uri": "https://client.example.net/return/123455", "uri": "https://client.example.net/return/123455",
"nonce": "LKLTI25DK82FX4T4QFZC" "nonce": "LKLTI25DK82FX4T4QFZC"
} }
} }
Requests to the callback URI MUST be processed by the client instance Requests to the callback URI MUST be processed by the client instance
as described in Section 4.2.1. as described in Section 4.2.1.
Since the incoming request to the callback URI is from the RO's Since the incoming request to the callback URI is from the RO's
browser, this method is usually used when the RO and end user are the browser, this method is usually used when the RO and end user are the
same entity. See Section 13.24 for considerations on ensuring the same entity. See Section 11.24 for considerations on ensuring the
incoming HTTP message matches the expected context of the request. incoming HTTP message matches the expected context of the request.
See Section 13.29 for more considerations regarding the use of front- See Section 11.29 for more considerations regarding the use of front-
channel communication techniques. channel communication techniques.
2.5.2.2. Receive an HTTP Direct Callback 2.5.2.2. Receive an HTTP Direct Callback
A finish method value of push indicates that the client instance will A finish method value of push indicates that the client instance will
expect a request from the AS directly using the HTTP method POST as expect a request from the AS directly using the HTTP method POST as
described in Section 4.2.2. described in Section 4.2.2.
The client instance's URI MUST be protected by HTTPS, be hosted on a The client instance's URI MUST be protected by HTTPS, be hosted on a
server local to the RO's browser ("localhost"), or use an server local to the RO's browser ("localhost"), or use an
skipping to change at page 55, line 18 skipping to change at line 2420
"uri": "https://client.example.net/return/123455", "uri": "https://client.example.net/return/123455",
"nonce": "LKLTI25DK82FX4T4QFZC" "nonce": "LKLTI25DK82FX4T4QFZC"
} }
} }
Requests to the callback URI MUST be processed by the client instance Requests to the callback URI MUST be processed by the client instance
as described in Section 4.2.2. as described in Section 4.2.2.
Since the incoming request to the callback URI is from the AS and not Since the incoming request to the callback URI is from the AS and not
from the RO's browser, this request is not expected to have any from the RO's browser, this request is not expected to have any
shared session information from the start method. See Section 13.24 shared session information from the start method. See Sections 11.24
and Section 13.23 for more considerations regarding the use of back- and 11.23 for more considerations regarding the use of back-channel
channel and polling mechanisms like this. and polling mechanisms like this.
2.5.3. Hints 2.5.3. Hints
The hints key is an object describing one or more suggestions from The hints key is an object describing one or more suggestions from
the client instance that the AS can use to help drive user the client instance that the AS can use to help drive user
interaction. interaction.
This specification defines the following properties under the hints This specification defines the following property under the hints
key: key:
ui_locales (array of strings): Indicates the end user's preferred ui_locales (array of strings): Indicates the end user's preferred
locales that the AS can use during interaction, particularly locales that the AS can use during interaction, particularly
before the RO has authenticated. OPTIONAL. Section 2.5.3.1 before the RO has authenticated. OPTIONAL. Section 2.5.3.1
The following sections detail requests for interaction hints. The following subsection details requests for interaction hints.
Additional interaction hints are defined in the GNAP Interaction Additional interaction hints can be defined in the "GNAP Interaction
Hints Registry (Section 11.11). Hints" registry (Section 10.11).
2.5.3.1. Indicate Desired Interaction Locales 2.5.3.1. Indicate Desired Interaction Locales
If the client instance knows the end user's locale and language If the client instance knows the end user's locale and language
preferences, the client instance can send this information to the AS preferences, the client instance can send this information to the AS
using the ui_locales field with an array of locale strings as defined using the ui_locales field with an array of locale strings as defined
by [RFC5646]. by [RFC5646].
"interact": { "interact": {
"hints": { "hints": {
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If the client instance knows the end user's locale and language If the client instance knows the end user's locale and language
preferences, the client instance can send this information to the AS preferences, the client instance can send this information to the AS
using the ui_locales field with an array of locale strings as defined using the ui_locales field with an array of locale strings as defined
by [RFC5646]. by [RFC5646].
"interact": { "interact": {
"hints": { "hints": {
"ui_locales": ["en-US", "fr-CA"] "ui_locales": ["en-US", "fr-CA"]
} }
} }
If possible, the AS SHOULD use one of the locales in the array, with If possible, the AS SHOULD use one of the locales in the array, with
preference to the first item in the array supported by the AS. If preference to the first item in the array supported by the AS. If
none of the given locales are supported, the AS MAY use a default none of the given locales are supported, the AS MAY use a default
locale. locale.
3. Grant Response 3. Grant Response
In response to a client instance's request, the AS responds with a In response to a client instance's request, the AS responds with a
JSON object as the HTTP content. Each possible field is detailed in JSON object as the HTTP content. Each possible field is detailed in
the sections below. the subsections below.
continue (object): Indicates that the client instance can continue continue (object): Indicates that the client instance can continue
the request by making one or more continuation requests. REQUIRED the request by making one or more continuation requests. REQUIRED
if continuation calls are allowed for this client instance on this if continuation calls are allowed for this client instance on this
grant request. See Section 3.1. grant request. See Section 3.1.
access_token (object / array of objects): A single access token or access_token (object / array of objects): A single access token or
set of access tokens that the client instance can use to call the set of access tokens that the client instance can use to call the
RS on behalf of the RO. REQUIRED if an access token is included. RS on behalf of the RO. REQUIRED if an access token is included.
See Section 3.2. See Section 3.2.
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Section 3.4. Section 3.4.
instance_id (string): An identifier this client instance can use to instance_id (string): An identifier this client instance can use to
identify itself when making future requests. OPTIONAL. See identify itself when making future requests. OPTIONAL. See
Section 3.5. Section 3.5.
error (object or string): An error code indicating that something error (object or string): An error code indicating that something
has gone wrong. REQUIRED for an error condition. See has gone wrong. REQUIRED for an error condition. See
Section 3.6. Section 3.6.
Additional fields can be defined by extensions to GNAP in the GNAP Additional fields can be defined by extensions to GNAP in the "GNAP
Grant Response Parameters Registry (Section 11.12). Grant Response Parameters" registry (Section 10.12).
In the following non-normative example, the AS is returning an In the following non-normative example, the AS is returning an
interaction URI (Section 3.3.1), a callback nonce (Section 3.3.5), interaction URI (Section 3.3.1), a callback nonce (Section 3.3.5),
and a continuation response (Section 3.1). and a continuation response (Section 3.1).
NOTE: '\' line wrapping per RFC 8792 NOTE: '\' line wrapping per RFC 8792
{ {
"interact": { "interact": {
"redirect": "https://server.example.com/interact/4CF492ML\ "redirect": "https://server.example.com/interact/4CF492ML\
skipping to change at page 57, line 44 skipping to change at line 2537
} }
}, },
"subject": { "subject": {
"sub_ids": [ { "sub_ids": [ {
"format": "opaque", "format": "opaque",
"id": "J2G8G8O4AZ" "id": "J2G8G8O4AZ"
} ] } ]
} }
} }
In following non-normative example, the AS is returning set of In the following non-normative example, the AS is returning set of
subject identifiers (Section 3.4), simultaneously as an opaque subject identifiers (Section 3.4), simultaneously as an opaque
identifier, an email address, and a decentralized identifier (DID), identifier, an email address, and a decentralized identifier (DID),
formatted as a set of Subject Identifiers defined in [RFC9493]. formatted as a set of Subject Identifiers as defined in [RFC9493].
{ {
"subject": { "subject": {
"sub_ids": [ { "sub_ids": [ {
"format": "opaque", "format": "opaque",
"id": "J2G8G8O4AZ" "id": "J2G8G8O4AZ"
}, { }, {
"format": "email", "format": "email",
"email": "user@example.com" "email": "user@example.com"
}, { }, {
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The authorization server MUST include the HTTP Cache-Control response The authorization server MUST include the HTTP Cache-Control response
header field [RFC9111] with a value set to "no-store". header field [RFC9111] with a value set to "no-store".
3.1. Request Continuation 3.1. Request Continuation
If the AS determines that the grant request can be continued by the If the AS determines that the grant request can be continued by the
client instance, the AS responds with the continue field. This field client instance, the AS responds with the continue field. This field
contains a JSON object with the following properties. contains a JSON object with the following properties.
uri (string): The URI at which the client instance can make uri (string): The URI at which the client instance can make
continuation requests. This URI MAY vary per request, or MAY be continuation requests. This URI MAY vary per request or MAY be
stable at the AS. This URI MUST be an absolute URI. The client stable at the AS. This URI MUST be an absolute URI. The client
instance MUST use this value exactly as given when making a instance MUST use this value exactly as given when making a
continuation request (Section 5). REQUIRED. continuation request (Section 5). REQUIRED.
wait (integer): The amount of time in integer seconds the client wait (integer): The amount of time in integer seconds the client
instance MUST wait after receiving this request continuation instance MUST wait after receiving this request continuation
response and calling the continuation URI. The value SHOULD NOT response and calling the continuation URI. The value SHOULD NOT
be less than five seconds, and omission of the value MUST be be less than five seconds, and omission of the value MUST be
interpreted as five seconds. RECOMMENDED. interpreted as five seconds. RECOMMENDED.
access_token (object): A unique access token for continuing the access_token (object): A unique access token for continuing the
request, called the "continuation access token". The value of request, called the "continuation access token". The value of
this property MUST be an object in the format specified in this property MUST be an object in the format specified in
Section 3.2.1. This access token MUST be bound to the client Section 3.2.1. This access token MUST be bound to the client
instance's key used in the request and MUST NOT be a bearer token. instance's key used in the request and MUST NOT be a bearer token.
As a consequence, the flags array of this access token MUST NOT As a consequence, the flags array of this access token MUST NOT
contain the string bearer and the key field MUST be omitted. This contain the string bearer, and the key field MUST be omitted.
access token MUST NOT have a manage field. The client instance This access token MUST NOT have a manage field. The client
MUST present the continuation access token in all requests to the instance MUST present the continuation access token in all
continuation URI as described in Section 7.2. REQUIRED. requests to the continuation URI as described in Section 7.2.
REQUIRED.
{ {
"continue": { "continue": {
"access_token": { "access_token": {
"value": "80UPRY5NM33OMUKMKSKU" "value": "80UPRY5NM33OMUKMKSKU"
}, },
"uri": "https://server.example.com/continue", "uri": "https://server.example.com/continue",
"wait": 60 "wait": 60
} }
} }
This field is REQUIRED if the grant request is in the _pending_ This field is REQUIRED if the grant request is in the _pending_
state, as the field contains the information needed by the client state, as the field contains the information needed by the client
request to continue the request as described in Section 5. Note that request to continue the request as described in Section 5. Note that
the continuation access token is bound to the client instance's key, the continuation access token is bound to the client instance's key;
and therefore the client instance MUST sign all continuation requests therefore, the client instance MUST sign all continuation requests
with its key as described in Section 7.3 and MUST present the with its key as described in Section 7.3 and MUST present the
continuation access token in its continuation request. continuation access token in its continuation request.
3.2. Access Tokens 3.2. Access Tokens
If the AS has successfully granted one or more access tokens to the If the AS has successfully granted one or more access tokens to the
client instance, the AS responds with the access_token field. This client instance, the AS responds with the access_token field. This
field contains either a single access token as described in field contains either a single access token as described in
Section 3.2.1 or an array of access tokens as described in Section 3.2.1 or an array of access tokens as described in
Section 3.2.2. Section 3.2.2.
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value (string): The value of the access token as a string. The value (string): The value of the access token as a string. The
value is opaque to the client instance. The value MUST be limited value is opaque to the client instance. The value MUST be limited
to the token68 character set defined in Section 11.2 of [HTTP] to to the token68 character set defined in Section 11.2 of [HTTP] to
facilitate transmission over HTTP headers and within other facilitate transmission over HTTP headers and within other
protocols without requiring additional encoding. REQUIRED. protocols without requiring additional encoding. REQUIRED.
label (string): The value of the label the client instance provided label (string): The value of the label the client instance provided
in the associated token request (Section 2.1), if present. in the associated token request (Section 2.1), if present.
REQUIRED for multiple access tokens or if a label was included in REQUIRED for multiple access tokens or if a label was included in
the single access token request, OPTIONAL for a single access the single access token request; OPTIONAL for a single access
token where no label was included in the request. token where no label was included in the request.
manage (object): Access information for the token management API for manage (object): Access information for the token management API for
this access token. The management URI for this access token. If this access token. The management URI for this access token. If
provided, the client instance MAY manage its access token as provided, the client instance MAY manage its access token as
described in Section 6. This management API is a function of the described in Section 6. This management API is a function of the
AS and is separate from the RS the client instance is requesting AS and is separate from the RS the client instance is requesting
access to. OPTIONAL. access to. OPTIONAL.
access (array of objects/strings): A description of the rights access (array of objects/strings): A description of the rights
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this time. Note that the access token MAY be revoked by the AS or this time. Note that the access token MAY be revoked by the AS or
RS at any point prior to its expiration. OPTIONAL. RS at any point prior to its expiration. OPTIONAL.
key (object / string): The key that the token is bound to, if key (object / string): The key that the token is bound to, if
different from the client instance's presented key. The key MUST different from the client instance's presented key. The key MUST
be an object or string in a format described in Section 7.1. The be an object or string in a format described in Section 7.1. The
client instance MUST be able to dereference or process the key client instance MUST be able to dereference or process the key
information in order to be able to sign subsequent requests using information in order to be able to sign subsequent requests using
the access token (Section 7.2). When the key is provided by value the access token (Section 7.2). When the key is provided by value
from the AS, the token shares some security properties with bearer from the AS, the token shares some security properties with bearer
tokens as discussed in Section 13.38. It is RECOMMENDED that keys tokens as discussed in Section 11.38. It is RECOMMENDED that keys
returned for use with access tokens be key references as described returned for use with access tokens be key references as described
in Section 7.1.1 that the client instance can correlate to its in Section 7.1.1 that the client instance can correlate to its
known keys. OPTIONAL. known keys. OPTIONAL.
flags (array of strings): A set of flags that represent attributes flags (array of strings): A set of flags that represent attributes
or behaviors of the access token issued by the AS. OPTIONAL. or behaviors of the access token issued by the AS. OPTIONAL.
The value of the manage field is an object with the following The value of the manage field is an object with the following
properties: properties:
uri (string): The URI of the token management API for this access uri (string): The URI of the token management API for this access
token. This URI MUST be an absolute URI. This URI MUST NOT include token. This URI MUST be an absolute URI. This URI MUST NOT
the access token value and SHOULD be different for each access token include the access token value, SHOULD be different for each
issued in a request and MUST NOT include the value of the access access token issued in a request, and MUST NOT include the value
token being managed. REQUIRED. of the access token being managed. REQUIRED.
access_token (object): A unique access token for continuing the access_token (object): A unique access token for continuing the
request, called the "token management access token". The value of request, called the "token management access token". The value of
this property MUST be an object in the format specified in this property MUST be an object in the format specified in
Section 3.2.1. This access token MUST be bound to the client Section 3.2.1. This access token MUST be bound to the client
instance's key used in the request (or its most recent rotation) instance's key used in the request (or its most recent rotation)
and MUST NOT be a bearer token. As a consequence, the flags array and MUST NOT be a bearer token. As a consequence, the flags array
of this access token MUST NOT contain the string bearer and the of this access token MUST NOT contain the string bearer, and the
key field MUST be omitted. This access token MUST NOT have a key field MUST be omitted. This access token MUST NOT have a
manage field. This access token MUST NOT have the same value as manage field. This access token MUST NOT have the same value as
the token it is managing. The client instance MUST present the the token it is managing. The client instance MUST present the
continuation access token in all requests to the continuation URI continuation access token in all requests to the continuation URI
as described in Section 7.2. REQUIRED. as described in Section 7.2. REQUIRED.
The values of the flags field defined by this specification are as The values of the flags field defined by this specification are as
follows: follows:
"bearer": This flag indicates whether the token is a bearer token, "bearer": Flag indicating whether the token is a bearer token, not
not bound to a key and proofing mechanism. If the bearer flag is bound to a key and proofing mechanism. If the bearer flag is
present, the access token is a bearer token, and the key field in present, the access token is a bearer token, and the key field in
this response MUST be omitted. See Section 13.9 for additional this response MUST be omitted. See Section 11.9 for additional
considerations on the use of bearer tokens. considerations on the use of bearer tokens.
"durable": Flag indicating a hint of AS behavior on token rotation. "durable": Flag indicating a hint of AS behavior on token rotation.
If this flag is present, then the client instance can expect a If this flag is present, then the client instance can expect a
previously-issued access token to continue to work after it has previously issued access token to continue to work after it has
been rotated (Section 6.1) or the underlying grant request has been rotated (Section 6.1) or the underlying grant request has
been modified (Section 5.3), resulting in the issuance of new been modified (Section 5.3), resulting in the issuance of new
access tokens. If this flag is omitted, the client instance can access tokens. If this flag is omitted, the client instance can
anticipate a given access token could stop working after token anticipate a given access token could stop working after token
rotation or grant request modification. Note that a token flagged rotation or grant request modification. Note that a token flagged
as durable can still expire or be revoked through any normal as durable can still expire or be revoked through any normal
means. means.
Flag values MUST NOT be included more than once. Flag values MUST NOT be included more than once.
Additional flags can be defined by extensions using the GNAP Access Additional flags can be defined by extensions using the "GNAP Access
Token Fields Registry (Section 11.4). Token Flags" registry (Section 10.4).
If the bearer flag and the key field in this response are omitted, If the bearer flag and the key field in this response are omitted,
the token is bound the key used by the client instance (Section 2.3) the token is bound to the key used by the client instance
in its request for access. If the bearer flag is omitted, and the (Section 2.3) in its request for access. If the bearer flag is
key field is present, the token is bound to the key and proofing omitted and the key field is present, the token is bound to the key
mechanism indicated in the key field. The means by which the AS and proofing mechanism indicated in the key field. The means by
determines how to bind an access token to a key other than that which the AS determines how to bind an access token to a key other
presented by the client instance is out of scope for this than that presented by the client instance are out of scope for this
specification, but common practices include pre-registering specific specification, but common practices include pre-registering specific
keys in a static fashion. keys in a static fashion.
The client software MUST reject any access token where the flags The client software MUST reject any access token where the flags
field contains the bearer flag and the key field is present with any field contains the bearer flag and the key field is present with any
value. value.
The following non-normative example shows a single access token bound The following non-normative example shows a single access token bound
to the client instance's key used in the initial request, with a to the client instance's key used in the initial request, with a
management URI, and that has access to three described resources (one management URI, and that has access to three described resources (one
skipping to change at page 63, line 15 skipping to change at line 2789
"access_token": { "access_token": {
"value": "OS9M2PMHKUR64TB8N6BW7OZB8CDFONP219RP1LT0", "value": "OS9M2PMHKUR64TB8N6BW7OZB8CDFONP219RP1LT0",
"flags": ["bearer"], "flags": ["bearer"],
"access": [ "access": [
"finance", "medical" "finance", "medical"
] ]
} }
If the client instance requested a single access token If the client instance requested a single access token
(Section 2.1.1), the AS MUST NOT respond with the multiple access (Section 2.1.1), the AS MUST NOT respond with the multiple access
token structure. tokens structure.
3.2.2. Multiple Access Tokens 3.2.2. Multiple Access Tokens
If the client instance has requested multiple access tokens and the If the client instance has requested multiple access tokens and the
AS has granted at least one of them, the AS responds with the AS has granted at least one of them, the AS responds with the
"access_token" field. The value of this field is a JSON array, the "access_token" field. The value of this field is a JSON array, the
members of which are distinct access tokens as described in members of which are distinct access tokens as described in
Section 3.2.1. Each object MUST have a unique label field, Section 3.2.1. Each object MUST have a unique label field,
corresponding to the token labels chosen by the client instance in corresponding to the token labels chosen by the client instance in
the multiple access token request (Section 2.1.2). the multiple access tokens request (Section 2.1.2).
In the following non-normative example, two tokens are issued under In the following non-normative example, two tokens are issued under
the names token1 and token2, and only the first token has a the names token1 and token2, and only the first token has a
management URI associated with it. management URI associated with it.
NOTE: '\' line wrapping per RFC 8792 NOTE: '\' line wrapping per RFC 8792
"access_token": [ "access_token": [
{ {
"label": "token1", "label": "token1",
skipping to change at page 64, line 4 skipping to change at line 2825
} }
}, },
"access": [ "finance" ] "access": [ "finance" ]
}, },
{ {
"label": "token2", "label": "token2",
"value": "UFGLO2FDAFG7VGZZPJ3IZEMN21EVU71FHCARP4J1", "value": "UFGLO2FDAFG7VGZZPJ3IZEMN21EVU71FHCARP4J1",
"access": [ "medical" ] "access": [ "medical" ]
} }
} }
Each access token corresponds to one of the objects in the Each access token corresponds to one of the objects in the
access_token array of the client instance's request (Section 2.1.2). access_token array of the client instance's request (Section 2.1.2).
The AS MAY refuse to issue one or more of the requested access The AS MAY refuse to issue one or more of the requested access tokens
tokens, for any reason. In such cases the refused token is omitted for any reason. In such cases, the refused token is omitted from the
from the response and all of the other issued access tokens are response, and all of the other issued access tokens are included in
included in the response under their respective requested labels. If the response under their respective requested labels. If the client
the client instance requested multiple access tokens (Section 2.1.2), instance requested multiple access tokens (Section 2.1.2), the AS
the AS MUST NOT respond with a single access token structure, even if MUST NOT respond with a single access token structure, even if only a
only a single access token is granted. In such cases, the AS MUST single access token is granted. In such cases, the AS MUST respond
respond with a multiple access token structure containing one access with a multiple access tokens structure containing one access token.
token.
"access_token": [ "access_token": [
{ {
"label": "token2", "label": "token2",
"value": "8N6BW7OZB8CDFONP219-OS9M2PMHKUR64TBRP1LT0", "value": "8N6BW7OZB8CDFONP219-OS9M2PMHKUR64TBRP1LT0",
"manage": { "manage": {
"uri": "https://server.example.com/token/PRY5NM33O", "uri": "https://server.example.com/token/PRY5NM33O",
"access_token": { "access_token": {
"value": "B8CDFONP21-4TB8N6.BW7ONM" "value": "B8CDFONP21-4TB8N6.BW7ONM"
} }
}, },
"access": [ "fruits" ] "access": [ "fruits" ]
} }
] ]
The parameters of each access token are separate. For example, each The parameters of each access token are separate. For example, each
access token is expected to have a unique value and (if present) access token is expected to have a unique value and (if present)
label, and likely has different access rights associated with it. label, and each access token likely has different access rights
Each access token could also be bound to different keys with associated with it. Each access token could also be bound to
different proofing mechanisms. different keys with different proofing mechanisms.
3.3. Interaction Modes 3.3. Interaction Modes
If the client instance has indicated a capability to interact with If the client instance has indicated a capability to interact with
the RO in its request (Section 2.5), and the AS has determined that the RO in its request (Section 2.5) and the AS has determined that
interaction is both supported and necessary, the AS responds to the interaction is both supported and necessary, the AS responds to the
client instance with any of the following values in the interact client instance with any of the following values in the interact
field of the response. There is no preference order for interaction field of the response. There is no preference order for interaction
modes in the response, and it is up to the client instance to modes in the response, and it is up to the client instance to
determine which ones to use. All supported interaction methods are determine which ones to use. All supported interaction methods are
included in the same interact object. included in the same interact object.
redirect (string): Redirect to an arbitrary URI. REQUIRED if the redirect (string): Redirect to an arbitrary URI. REQUIRED if the
redirect interaction start mode is possible for this request. See redirect interaction start mode is possible for this request. See
Section 3.3.1. Section 3.3.1.
skipping to change at page 65, line 26 skipping to change at line 2894
finish (string): A unique ASCII string value provided by the AS as a finish (string): A unique ASCII string value provided by the AS as a
nonce. This is used by the client instance to verify the callback nonce. This is used by the client instance to verify the callback
after interaction is completed. REQUIRED if the interaction after interaction is completed. REQUIRED if the interaction
finish method requested by the client instance is possible for finish method requested by the client instance is possible for
this request. See Section 3.3.5. this request. See Section 3.3.5.
expires_in (integer): The number of integer seconds after which this expires_in (integer): The number of integer seconds after which this
set of interaction responses will expire and no longer be usable set of interaction responses will expire and no longer be usable
by the client instance. If the interaction methods expire, the by the client instance. If the interaction methods expire, the
client MAY re-start the interaction process for this grant request client MAY restart the interaction process for this grant request
by sending an update (Section 5.3) with a new interaction request by sending an update (Section 5.3) with a new interaction request
(Section 2.5) section. OPTIONAL. If omitted, the interaction section (Section 2.5). OPTIONAL. If omitted, the interaction
response modes returned do not expire but MAY be invalidated by response modes returned do not expire but MAY be invalidated by
the AS at any time. the AS at any time.
Additional interaction mode responses can be defined in the GNAP Additional interaction mode responses can be defined in the "GNAP
Interaction Mode Responses Registry (Section 11.13). Interaction Mode Responses" registry (Section 10.13).
The AS MUST NOT respond with any interaction mode that the client The AS MUST NOT respond with any interaction mode that the client
instance did not indicate in its request. The AS MUST NOT respond instance did not indicate in its request, and the AS MUST NOT respond
with any interaction mode that the AS does not support. Since with any interaction mode that the AS does not support. Since
interaction responses include secret or unique information, the AS interaction responses include secret or unique information, the AS
SHOULD respond to each interaction mode only once in an ongoing SHOULD respond to each interaction mode only once in an ongoing
request, particularly if the client instance modifies its request request, particularly if the client instance modifies its request
(Section 5.3). (Section 5.3).
The grant request MUST be in the _pending_ state to include this The grant request MUST be in the _pending_ state to include this
field in the response. field in the response.
3.3.1. Redirection to an arbitrary URI 3.3.1. Redirection to an Arbitrary URI
If the client instance indicates that it can redirect to an arbitrary If the client instance indicates that it can redirect to an arbitrary
URI (Section 2.5.1.1) and the AS supports this mode for the client URI (Section 2.5.1.1) and the AS supports this mode for the client
instance's request, the AS responds with the "redirect" field, which instance's request, the AS responds with the "redirect" field, which
is a string containing the URI for the end user to visit. This URI is a string containing the URI for the end user to visit. This URI
MUST be unique for the request and MUST NOT contain any security- MUST be unique for the request and MUST NOT contain any security-
sensitive information such as user identifiers or access tokens. sensitive information such as user identifiers or access tokens.
"interact": { "interact": {
"redirect": "https://interact.example.com/4CF492MLVMSW9MKMXKHQ" "redirect": "https://interact.example.com/4CF492MLVMSW9MKMXKHQ"
} }
The URI returned is a function of the AS, but the URI itself MAY be The URI returned is a function of the AS, but the URI itself MAY be
completely distinct from the grant endpoint URI that the client completely distinct from the grant endpoint URI that the client
instance uses to request access (Section 2), allowing an AS to instance uses to request access (Section 2), allowing an AS to
separate its user-interactive functionality from its back-end separate its user-interaction functionality from its back-end
security functionality. The AS will need to dereference the specific security functionality. The AS will need to dereference the specific
grant request and its information from the URI alone. If the AS does grant request and its information from the URI alone. If the AS does
not directly host the functionality accessed through the redirect not directly host the functionality accessed through the redirect
URI, then the means for the interaction functionality to communicate URI, then the means for the interaction functionality to communicate
with the rest of the AS are out of scope for this specification. with the rest of the AS are out of scope for this specification.
The client instance sends the end user to the URI to interact with The client instance sends the end user to the URI to interact with
the AS. The client instance MUST NOT alter the URI in any way. The the AS. The client instance MUST NOT alter the URI in any way. The
means for the client instance to send the end user to this URI is out means for the client instance to send the end user to this URI are
of scope of this specification, but common methods include an HTTP out of scope of this specification, but common methods include an
redirect, launching the system browser, displaying a scannable code, HTTP redirect, launching the system browser, displaying a scannable
or printing out the URI in an interactive console. See details of code, or printing out the URI in an interactive console. See details
the interaction in Section 4.1.1. of the interaction in Section 4.1.1.
3.3.2. Launch of an application URI 3.3.2. Launch of an Application URI
If the client instance indicates that it can launch an application If the client instance indicates that it can launch an application
URI (Section 2.5.1.2) and the AS supports this mode for the client URI (Section 2.5.1.2) and the AS supports this mode for the client
instance's request, the AS responds with the "app" field, which is a instance's request, the AS responds with the "app" field, which is a
string containing the URI for the client instance to launch. This string containing the URI for the client instance to launch. This
URI MUST be unique for the request and MUST NOT contain any security- URI MUST be unique for the request and MUST NOT contain any security-
sensitive information such as user identifiers or access tokens. sensitive information such as user identifiers or access tokens.
"interact": { "interact": {
"app": "https://app.example.com/launch?tx=4CF492MLV" "app": "https://app.example.com/launch?tx=4CF492MLV"
} }
The means for the launched application to communicate with the AS are The means for the launched application to communicate with the AS are
out of scope for this specification. out of scope for this specification.
The client instance launches the URI as appropriate on its platform, The client instance launches the URI as appropriate on its platform;
and the means for the client instance to launch this URI is out of the means for the client instance to launch this URI are out of scope
scope of this specification. The client instance MUST NOT alter the of this specification. The client instance MUST NOT alter the URI in
URI in any way. The client instance MAY attempt to detect if an any way. The client instance MAY attempt to detect if an installed
installed application will service the URI being sent before application will service the URI being sent before attempting to
attempting to launch the application URI. See details of the launch the application URI. See details of the interaction in
interaction in Section 4.1.4. Section 4.1.4.
3.3.3. Display of a Short User Code 3.3.3. Display of a Short User Code
If the client instance indicates that it can display a short If the client instance indicates that it can display a short, user-
user-typeable code (Section 2.5.1.3) and the AS supports this mode typeable code (Section 2.5.1.3) and the AS supports this mode for the
for the client instance's request, the AS responds with a "user_code" client instance's request, the AS responds with a "user_code" field.
field. This field is string containing a unique short code that the This field is string containing a unique short code that the user can
user can type into a web page. To facilitate usability, this string type into a web page. To facilitate usability, this string MUST
MUST consist only of characters that can be easily typed by the end consist only of characters that can be easily typed by the end user
user (such as ASCII letters or numbers) and MUST be processed by the (such as ASCII letters or numbers) and MUST be processed by the AS in
AS in a case-insensitive manner (see Section 4.1.2). The string MUST a case-insensitive manner (see Section 4.1.2). The string MUST be
be randomly generated so as to be unguessable by an attacker within randomly generated so as to be unguessable by an attacker within the
the time it is accepted. The time in which this code will be time it is accepted. The time in which this code will be accepted
accepted SHOULD be short lived, such as several minutes. It is SHOULD be short lived, such as several minutes. It is RECOMMENDED
RECOMMENDED that this code be no more than eight characters in that this code be between six and eight characters in length.
length.
"interact": { "interact": {
"user_code": "A1BC3DFF" "user_code": "A1BC3DFF"
} }
The client instance MUST communicate the "user_code" value to the end The client instance MUST communicate the "user_code" value to the end
user in some fashion, such as displaying it on a screen or reading it user in some fashion, such as displaying it on a screen or reading it
out audibly. This code is used by the interaction component of the out audibly. This code is used by the interaction component of the
AS as a means of identifying the pending grant request and does not AS as a means of identifying the pending grant request and does not
function as an authentication factor for the RO. function as an authentication factor for the RO.
The URI that the end user is intended to enter the code into MUST be The URI that the end user is intended to enter the code into MUST be
stable, since the client instance is expected to have no means of stable, since the client instance is expected to have no means of
communicating a dynamic URI to the end user at runtime. communicating a dynamic URI to the end user at runtime.
As this interaction mode is designed to facilitate interaction via a As this interaction mode is designed to facilitate interaction via a
secondary device, it is not expected that the client instance secondary device, it is not expected that the client instance
redirect the end user to the URI where the code is entered. If the redirect the end user to the URI where the code is entered. If the
client instance is capable of communicating an short arbitrary URI to client instance is capable of communicating a short arbitrary URI to
the end user for use with the user code, the client instance SHOULD the end user for use with the user code, the client instance SHOULD
instead use the "user_code_uri" (Section 2.5.1.4) mode. If the instead use the "user_code_uri" mode (Section 2.5.1.4). If the
client instance is capable of communicating a long arbitrary URI to client instance is capable of communicating a long arbitrary URI to
the end user, such as through a scannable code, the client instance the end user, such as through a scannable code, the client instance
SHOULD use the "redirect" (Section 2.5.1.1) mode for this purpose SHOULD use the "redirect" mode (Section 2.5.1.1) for this purpose,
instead of or in addition to the user code mode. instead of or in addition to the user code mode.
See details of the interaction in Section 4.1.2. See details of the interaction in Section 4.1.2.
3.3.4. Display of a Short User Code and URI 3.3.4. Display of a Short User Code and URI
If the client instance indicates that it can display a short If the client instance indicates that it can display a short, user-
user-typeable code (Section 2.5.1.3) and the AS supports this mode typeable code (Section 2.5.1.3) and the AS supports this mode for the
for the client instance's request, the AS responds with a client instance's request, the AS responds with a "user_code_uri"
"user_code_uri" object that contains the following members. object that contains the following members.
code (string): A unique short code that the end user can type into a code (string): A unique short code that the end user can type into a
provided URI. To facilitate usability, this string MUST consist provided URI. To facilitate usability, this string MUST consist
only of characters that can be easily typed by the end user (such only of characters that can be easily typed by the end user (such
as ASCII letters or numbers) and MUST be processed by the AS in a as ASCII letters or numbers) and MUST be processed by the AS in a
case-insensitive manner (see Section 4.1.3). The string MUST be case-insensitive manner (see Section 4.1.3). The string MUST be
randomly generated so as to be unguessable by an attacker within randomly generated so as to be unguessable by an attacker within
the time it is accepted. The time in which this code will be the time it is accepted. The time in which this code will be
accepted SHOULD be short lived, such as several minutes. It is accepted SHOULD be short lived, such as several minutes. It is
RECOMMENDED that this code be no more than eight characters in RECOMMENDED that this code be between six and eight characters in
length. REQUIRED. length. REQUIRED.
uri (string): The interaction URI that the client instance will uri (string): The interaction URI that the client instance will
direct the RO to. This URI MUST be short enough to be direct the RO to. This URI MUST be short enough to be
communicated to the end user by the client instance. It is communicated to the end user by the client instance. It is
RECOMMENDED that this URI be short enough for an end user to type RECOMMENDED that this URI be short enough for an end user to type
in manually. The URI MUST NOT contain the code value. This URI in manually. The URI MUST NOT contain the code value. This URI
MUST be an absolute URI. REQUIRED. MUST be an absolute URI. REQUIRED.
"interact": { "interact": {
skipping to change at page 69, line 4 skipping to change at line 3057
function as an authentication factor for the RO. function as an authentication factor for the RO.
The client instance MUST also communicate the URI to the end user. The client instance MUST also communicate the URI to the end user.
Since it is expected that the end user will continue interaction on a Since it is expected that the end user will continue interaction on a
secondary device, the URI needs to be short enough to allow the end secondary device, the URI needs to be short enough to allow the end
user to type or copy it to a secondary device without mistakes. user to type or copy it to a secondary device without mistakes.
The URI returned is a function of the AS, but the URI itself MAY be The URI returned is a function of the AS, but the URI itself MAY be
completely distinct from the grant endpoint URI that the client completely distinct from the grant endpoint URI that the client
instance uses to request access (Section 2), allowing an AS to instance uses to request access (Section 2), allowing an AS to
separate its user-interactive functionality from its back-end separate its user-interaction functionality from its back-end
security functionality. If the AS does not directly host the security functionality. If the AS does not directly host the
functionality accessed through the given URI, then the means for the functionality accessed through the given URI, then the means for the
interaction functionality to communicate with the rest of the AS are interaction functionality to communicate with the rest of the AS are
out of scope for this specification. out of scope for this specification.
See details of the interaction in Section 4.1.2. See details of the interaction in Section 4.1.2.
3.3.5. Interaction Finish 3.3.5. Interaction Finish
If the client instance indicates that it can receive a If the client instance indicates that it can receive a post-
post-interaction redirect or push at a URI (Section 2.5.2) and the AS interaction redirect or push at a URI (Section 2.5.2) and the AS
supports this mode for the client instance's request, the AS responds supports this mode for the client instance's request, the AS responds
with a finish field containing a nonce that the client instance will with a finish field containing a nonce that the client instance will
use in validating the callback as defined in Section 4.2. use in validating the callback as defined in Section 4.2.
"interact": { "interact": {
"finish": "MBDOFXG4Y5CVJCX821LH" "finish": "MBDOFXG4Y5CVJCX821LH"
} }
When the interaction is completed, the interaction component of the When the interaction is completed, the interaction component of the
AS MUST contact the client instance using the means defined by the AS MUST contact the client instance using the means defined by the
skipping to change at page 69, line 49 skipping to change at line 3102
are the same party. This can be accomplished through some forms of are the same party. This can be accomplished through some forms of
interaction with the RO (Section 4). interaction with the RO (Section 4).
This field is an object with the following properties. This field is an object with the following properties.
sub_ids (array of objects): An array of subject identifiers for the sub_ids (array of objects): An array of subject identifiers for the
RO, as defined by [RFC9493]. REQUIRED if returning subject RO, as defined by [RFC9493]. REQUIRED if returning subject
identifiers. identifiers.
assertions (array of objects): An array containing assertions as assertions (array of objects): An array containing assertions as
objects each containing the assertion object described below. objects, each containing the assertion object described below.
REQUIRED if returning assertions. REQUIRED if returning assertions.
updated_at (string): Timestamp as an [RFC3339] date string, updated_at (string): Timestamp as a date string as described in
indicating when the identified account was last updated. The [RFC3339], indicating when the identified account was last
client instance MAY use this value to determine if it needs to updated. The client instance MAY use this value to determine if
request updated profile information through an identity API. The it needs to request updated profile information through an
definition of such an identity API is out of scope for this identity API. The definition of such an identity API is out of
specification. RECOMMENDED. scope for this specification. RECOMMENDED.
Assertion objects contain the following fields: Assertion objects contain the following fields:
format (string): The assertion format. Possible formats are listed format (string): The assertion format. Possible formats are listed
in Section 3.4.1. Additional assertion formats are defined by the in Section 3.4.1. Additional assertion formats can be defined in
GNAP Assertion Formats Registry (Section 11.6). REQUIRED. the "GNAP Assertion Formats" registry (Section 10.6). REQUIRED.
value (string): The assertion value as the JSON string serialization value (string): The assertion value as the JSON string serialization
of the assertion. REQUIRED. of the assertion. REQUIRED.
The following non-normative example contains an opaque identifier and The following non-normative example contains an opaque identifier and
an OpenID Connect ID Token: an OpenID Connect ID Token:
"subject": { "subject": {
"sub_ids": [ { "sub_ids": [ {
"format": "opaque", "format": "opaque",
"id": "XUT2MFM1XBIKJKSDU8QM" "id": "XUT2MFM1XBIKJKSDU8QM"
} ], } ],
"assertions": [ { "assertions": [ {
"format": "id_token", "format": "id_token",
"value": "eyj..." "value": "eyj..."
} ] } ]
} }
Subject identifiers returned by the AS SHOULD uniquely identify the Subject identifiers returned by the AS SHOULD uniquely identify the
RO at the AS. Some forms of subject identifier are opaque to the RO at the AS. Some forms of subject identifiers are opaque to the
client instance (such as the subject of an issuer and subject pair), client instance (such as the subject of an issuer and subject pair),
while others forms (such as email address and phone number) are while other forms (such as email address and phone number) are
intended to allow the client instance to correlate the identifier intended to allow the client instance to correlate the identifier
with other account information at the client instance. The client with other account information at the client instance. The client
instance MUST NOT request or use any returned subject identifiers for instance MUST NOT request or use any returned subject identifiers for
communication purposes (see Section 2.2). That is, a subject communication purposes (see Section 2.2). That is, a subject
identifier returned in the format of an email address or a phone identifier returned in the format of an email address or a phone
number only identifies the RO to the AS and does not indicate that number only identifies the RO to the AS and does not indicate that
the AS has validated that the represented email address or phone the AS has validated that the represented email address or phone
number in the identifier is suitable for communication with the number in the identifier is suitable for communication with the
current user. To get such information, the client instance MUST use current user. To get such information, the client instance MUST use
an identity protocol to request and receive additional identity an identity protocol to request and receive additional identity
claims. The details of an identity protocol and associated schema claims. The details of an identity protocol and associated schema
are outside the scope of this specification. are outside the scope of this specification.
The AS MUST ensure that the returned subject information represents The AS MUST ensure that the returned subject information represents
the RO. In most cases, the AS will also ensure that the returned the RO. In most cases, the AS will also ensure that the returned
subject information represents the end user authenticated subject information represents the end user authenticated
interactively at the AS. The AS SHOULD NOT re-use subject interactively at the AS. The AS SHOULD NOT reuse subject identifiers
identifiers for multiple different ROs. for multiple different ROs.
The "sub_ids" and "assertions" response fields are independent of The "sub_ids" and "assertions" response fields are independent of
each other. That is, a returned assertion MAY use a different each other. That is, a returned assertion MAY use a different
subject identifier than other assertions and subject identifiers in subject identifier than other assertions and subject identifiers in
the response. However, all subject identifiers and assertions the response. However, all subject identifiers and assertions
returned MUST refer to the same party. returned MUST refer to the same party.
The client instance MUST interpret all subject information in the The client instance MUST interpret all subject information in the
context of the AS from which the subject information is received, as context of the AS from which the subject information is received, as
is discussed in Section 6 of [SP80063C]. For example, one AS could is discussed in Section 6 of [SP80063C]. For example, one AS could
return an email identifier of "user@example.com" for one RO, and a return an email identifier of "user@example.com" for one RO, and a
different AS could return that same email identifier of different AS could return that same email identifier of
"user@example.com" for a completely different RO. A client instance "user@example.com" for a completely different RO. A client instance
talking to both AS's needs to differentiate between these two talking to both ASes needs to differentiate between these two
accounts by accounting for the AS source of each identifier and not accounts by accounting for the AS source of each identifier and not
assuming that either has a canonical claim on the identifier without assuming that either has a canonical claim on the identifier without
additional configuration and trust agreements. Otherwise, a rogue AS additional configuration and trust agreements. Otherwise, a rogue AS
could exploit this to take over a targeted account asserted by a could exploit this to take over a targeted account asserted by a
different AS. different AS.
Extensions to this specification MAY define additional response Extensions to this specification MAY define additional response
properties in the GNAP Subject Information Response Fields Registry properties in the "GNAP Subject Information Response Fields" registry
(Section 11.14). (Section 10.14).
The grant request MUST be in the _approved_ state to return this The grant request MUST be in the _approved_ state to return this
field in the response. field in the response.
See Section 13.30 for considerations that the client instance has to See Section 11.30 for considerations that the client instance has to
make when accepting and processing assertions from the AS. make when accepting and processing assertions from the AS.
3.4.1. Assertion Formats 3.4.1. Assertion Formats
The following assertion formats are defined in this specification: The following assertion formats are defined in this specification:
id_token: An OpenID Connect ID Token ([OIDC]), in JWT compact format id_token: An OpenID Connect ID Token [OIDC], in JSON Web Token (JWT)
as a single string. compact format as a single string.
saml2: A SAML 2 assertion ([SAML2]), encoded as a single base64url saml2: A SAML 2 assertion [SAML2], encoded as a single base64url
string with no padding. string with no padding.
3.5. Returning a Dynamically-bound Client Instance Identifier 3.5. Returning a Dynamically Bound Client Instance Identifier
Many parts of the client instance's request can be passed as either a Many parts of the client instance's request can be passed as either a
value or a reference. The use of a reference in place of a value value or a reference. The use of a reference in place of a value
allows for a client instance to optimize requests to the AS. allows for a client instance to optimize requests to the AS.
Some references, such as for the client instance's identity Some references, such as for the client instance's identity
(Section 2.3.1) or the requested resources (Section 8.1), can be (Section 2.3.1) or the requested resources (Section 8.1), can be
managed statically through an admin console or developer portal managed statically through an admin console or developer portal
provided by the AS or RS. The developer of the client software can provided by the AS or RS. The developer of the client software can
include these values in their code for a more efficient and compact include these values in their code for a more efficient and compact
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information that would compromise any party if revealed. Instance information that would compromise any party if revealed. Instance
identifier values are opaque to the client instance, and their identifier values are opaque to the client instance, and their
content is determined by the AS. The instance identifier MUST be content is determined by the AS. The instance identifier MUST be
unique per client instance at the AS. unique per client instance at the AS.
instance_id (string): A string value used to represent the instance_id (string): A string value used to represent the
information in the client object that the client instance can use information in the client object that the client instance can use
in a future request, as described in Section 2.3.1. OPTIONAL. in a future request, as described in Section 2.3.1. OPTIONAL.
The following non-normative example shows an instance identifier The following non-normative example shows an instance identifier
along side an issued access token. alongside an issued access token.
{ {
"instance_id": "7C7C4AZ9KHRS6X63AJAO", "instance_id": "7C7C4AZ9KHRS6X63AJAO",
"access_token": { "access_token": {
"value": "OS9M2PMHKUR64TB8N6BW7OZB8CDFONP219RP1LT0" "value": "OS9M2PMHKUR64TB8N6BW7OZB8CDFONP219RP1LT0"
} }
} }
3.6. Error Response 3.6. Error Response
If the AS determines that the request cannot be completed for any If the AS determines that the request cannot be completed for any
reason, it responds to the client instance with an error field in the reason, it responds to the client instance with an error field in the
response message. This field is either an object or a string. response message. This field is either an object or a string.
When returned as an object, the object contains the following fields: When returned as an object, the object contains the following fields:
code (string): A single ASCII error code defining the error. The code (string): A single ASCII error code defining the error. The
value MUST be defined in the GNAP Error Codes Registry value MUST be defined in the "GNAP Error Codes" registry
(Section 11.15). REQUIRED. (Section 10.15). REQUIRED.
description (string): A human-readable string description of the description (string): A human-readable string description of the
error intended for the developer of the client. The value is error intended for the developer of the client. The value is
chosen by the implementation. OPTIONAL. chosen by the implementation. OPTIONAL.
This specification defines the following code values: This specification defines the following code values:
"invalid_request": The request is missing a required parameter, "invalid_request": The request is missing a required parameter,
includes an invalid parameter value or is otherwise malformed. includes an invalid parameter value, or is otherwise malformed.
"invalid_client": The request was made from a client that was not "invalid_client": The request was made from a client that was not
recognized or allowed by the AS, or the client's signature recognized or allowed by the AS, or the client's signature
validation failed. validation failed.
"invalid_interaction" The client instance has provided an "invalid_interaction": The client instance has provided an
interaction reference that is incorrect for this request or the interaction reference that is incorrect for this request, or the
interaction modes in use have expired. interaction modes in use have expired.
"invalid_flag" The flag configuration is not valid. "invalid_flag": The flag configuration is not valid.
"invalid_rotation" The token rotation request is not valid. "invalid_rotation": The token rotation request is not valid.
"key_rotation_not_supported" The AS does not allow rotation of this "key_rotation_not_supported": The AS does not allow rotation of this
access token's key. access token's key.
"invalid_continuation": The continuation of the referenced grant "invalid_continuation": The continuation of the referenced grant
could not be processed. could not be processed.
"user_denied": The RO denied the request. "user_denied": The RO denied the request.
"request_denied": The request was denied for an unspecified reason. "request_denied": The request was denied for an unspecified reason.
"unknown_user": The user presented in the request is not known to "unknown_user": The user presented in the request is not known to
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"unknown_interaction": The interaction integrity could not be "unknown_interaction": The interaction integrity could not be
established. established.
"too_fast": The client instance did not respect the timeout in the "too_fast": The client instance did not respect the timeout in the
wait response before the next call. wait response before the next call.
"too_many_attempts": A limit has been reached in the total number of "too_many_attempts": A limit has been reached in the total number of
reasonable attempts. This number is either defined statically or reasonable attempts. This number is either defined statically or
adjusted based on runtime conditions by the AS. adjusted based on runtime conditions by the AS.
Additional error codes can be defined in the GNAP Error Codes Additional error codes can be defined in the "GNAP Error Codes"
Registry (Section 11.15). registry (Section 10.15).
For example, if the RO denied the request while interacting with the For example, if the RO denied the request while interacting with the
AS, the AS would return the following error when the client instance AS, the AS would return the following error when the client instance
tries to continue the grant request: tries to continue the grant request:
{ {
"error": { "error": {
"code": "user_denied", "code": "user_denied",
"description": "The RO denied the request" "description": "The RO denied the request"
} }
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considered functionally equivalent to the previous example for the considered functionally equivalent to the previous example for the
purposes of the client software's understanding: purposes of the client software's understanding:
{ {
"error": "user_denied" "error": "user_denied"
} }
If an error state is reached but the grant is in the _pending_ state If an error state is reached but the grant is in the _pending_ state
(and therefore the client instance can continue), the AS MAY include (and therefore the client instance can continue), the AS MAY include
the continue field in the response along with the error, as defined the continue field in the response along with the error, as defined
Section 3.1. This allows the client instance to modify its request in Section 3.1. This allows the client instance to modify its
for access, potentially leading to prompting the RO again. Other request for access, potentially leading to prompting the RO again.
fields MUST NOT be included in the response. Other fields MUST NOT be included in the response.
4. Determining Authorization and Consent 4. Determining Authorization and Consent
When the client instance makes its initial request (Section 2) to the When the client instance makes its initial request (Section 2) to the
AS for delegated access, it is capable of asking for several AS for delegated access, it is capable of asking for several
different kinds of information in response: different kinds of information in response:
* the access being requested, in the access_token request parameter * the access being requested, in the access_token request parameter
* the subject information being requested, in the subject request * the subject information being requested, in the subject request
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When the grant request is in the _processing_ state, the AS When the grant request is in the _processing_ state, the AS
determines what authorizations and consents are required to fulfill determines what authorizations and consents are required to fulfill
this requested delegation. The details of how the AS makes this this requested delegation. The details of how the AS makes this
determination are out of scope for this document. However, there are determination are out of scope for this document. However, there are
several common patterns defined and supported by GNAP for fulfilling several common patterns defined and supported by GNAP for fulfilling
these requirements, including information sent by the client these requirements, including information sent by the client
instance, information gathered through the interaction process, and instance, information gathered through the interaction process, and
information supplied by external parties. An individual AS can information supplied by external parties. An individual AS can
define its own policies and processes for deciding when and how to define its own policies and processes for deciding when and how to
gather the necessary authorizations and consent, and how those are gather the necessary authorizations and consent and how those are
applied to the grant request. applied to the grant request.
To facilitate the AS fulfilling this request, the client instance To facilitate the AS fulfilling this request, the client instance
sends information about the actions the client software can take, sends information about the actions the client software can take,
including: including:
* starting interaction with the end user, in the interact request * starting interaction with the end user, in the interact request
parameter parameter
* receiving notification that interaction with the RO has concluded, * receiving notification that interaction with the RO has concluded,
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determines that the information presented in the initial request is determines that the information presented in the initial request is
sufficient for granting the requested access, the AS MAY move the sufficient for granting the requested access, the AS MAY move the
grant request to the _approved_ state and return results immediately grant request to the _approved_ state and return results immediately
in its response (Section 3) with access tokens and subject in its response (Section 3) with access tokens and subject
information. information.
If the AS determines that additional runtime authorization is If the AS determines that additional runtime authorization is
required, the AS can either deny the request outright (if there is no required, the AS can either deny the request outright (if there is no
possible recovery) or move the grant request to the _pending_ state possible recovery) or move the grant request to the _pending_ state
and use a number of means at its disposal to gather that and use a number of means at its disposal to gather that
authorization from the appropriate ROs, including for example: authorization from the appropriate ROs, including:
* starting interaction with the end user facilitated by the client * starting interaction with the end user facilitated by the client
software, such as a redirection or user code software, such as a redirection or user code
* challenging the client instance through a challenge-response * challenging the client instance through a challenge-response
mechanism mechanism
* requesting that the client instance present specific additional * requesting that the client instance present specific additional
information, such as a user's credential or an assertion information, such as a user's credential or an assertion
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record, an identified subject, or a request requiring specific access record, an identified subject, or a request requiring specific access
such as approval by an administrator. In other cases, the request is such as approval by an administrator. In other cases, the request is
applied to whichever RO is present at the time of consent gathering. applied to whichever RO is present at the time of consent gathering.
This pattern is especially prevalent when the end user is sent to the This pattern is especially prevalent when the end user is sent to the
AS for an interactive session, during which the end user takes on the AS for an interactive session, during which the end user takes on the
role of the RO. In these cases, the end user is delegating their own role of the RO. In these cases, the end user is delegating their own
access as RO to the client instance. access as RO to the client instance.
The client instance can indicate that it is capable of facilitating The client instance can indicate that it is capable of facilitating
interaction with the end user, another party, or another piece of interaction with the end user, another party, or another piece of
software through its interaction start (Section 2.5.1) request. software through its interaction start request (Section 2.5.1).
Here, the AS usually needs to interact directly with the end user to Here, the AS usually needs to interact directly with the end user to
determine their identity, determine their status as an RO, and determine their identity, determine their status as an RO, and
collect their consent. If the AS has determined that authorization collect their consent. If the AS has determined that authorization
is required and the AS can support one or more of the requested is required and the AS can support one or more of the requested
interaction start methods, the AS returns the associated interaction interaction start methods, the AS returns the associated interaction
start responses (Section 3.3). The client instance SHOULD initiate start responses (Section 3.3). The client instance SHOULD initiate
one or more of these interaction methods (Section 4.1) in order to one or more of these interaction methods (Section 4.1) in order to
facilitate the granting of the request. If more than one interaction facilitate the granting of the request. If more than one interaction
start method is available, the means by which the client chooses start method is available, the means by which the client chooses
which methods to follow is out of scope of this specification. which methods to follow are out of scope of this specification.
After starting interaction, the client instance can then make a After starting interaction, the client instance can then make a
continuation request (Section 5) either in response to a signal continuation request (Section 5) either in response to a signal
indicating the finish of the interaction (Section 4.2), after a time- indicating the finish of the interaction (Section 4.2), after a time-
based polling, or through some other method defined by an extension based polling, or through some other method defined by an extension
of this specification through the GNAP Interaction Mode Responses of this specification through the "GNAP Interaction Mode Responses"
registry (Section 11.13). registry (Section 10.13).
If the grant request is not in the _approved_ state, the client If the grant request is not in the _approved_ state, the client
instance can repeat the interaction process by sending a grant update instance can repeat the interaction process by sending a grant update
request (Section 5.3) with new interaction (Section 2.5) methods. request (Section 5.3) with new interaction methods (Section 2.5).
The client instance MUST use each interaction method at most once, if The client instance MUST use each interaction method once at most if
a response can be detected. The AS MUST handle any interact request a response can be detected. The AS MUST handle any interact request
as a one-time-use mechanism and SHOULD apply suitable timeouts to any as a one-time-use mechanism and SHOULD apply suitable timeouts to any
interaction start methods provided, including user codes and interaction start methods provided, including user codes and
redirection URIs. The client instance SHOULD apply suitable timeouts redirection URIs. The client instance SHOULD apply suitable timeouts
to any interaction finish method. to any interaction finish method.
In order to support client software deployed in disadvantaged network In order to support client software deployed in disadvantaged network
conditions, the AS MAY allow for processing of the same interaction conditions, the AS MAY allow for processing of the same interaction
method multiple times if the AS can determine that the request is method multiple times if the AS can determine that the request is
from the same party and the results are idempotent. For example, if from the same party and the results are idempotent. For example, if
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first place. However, if the AS in question receives both requests, first place. However, if the AS in question receives both requests,
it could mistakenly process them separately, creating an undefined it could mistakenly process them separately, creating an undefined
state for the client instance. If the AS can determine that both state for the client instance. If the AS can determine that both
requests come from the same origin or under the same session, and the requests come from the same origin or under the same session, and the
requests both came before any additional state change to the grant requests both came before any additional state change to the grant
occurs, the AS can reasonably conclude that the initial response was occurs, the AS can reasonably conclude that the initial response was
not received and the same response can be returned to the client not received and the same response can be returned to the client
instance. instance.
If the AS instead has a means of contacting the RO directly, it could If the AS instead has a means of contacting the RO directly, it could
do so without involving the client instance in its consent gathering do so without involving the client instance in its consent-gathering
process. For example, the AS could push a notification to a known RO process. For example, the AS could push a notification to a known RO
and have the RO approve the pending request asynchronously. These and have the RO approve the pending request asynchronously. These
interactions can be through an interface of the AS itself (such as a interactions can be through an interface of the AS itself (such as a
hosted web page), through another application (such as something hosted web page), through another application (such as something
installed on the RO's device), through a messaging fabric, or any installed on the RO's device), through a messaging fabric, or any
other means. other means.
When interacting with an RO, the AS can do anything it needs to When interacting with an RO, the AS can do anything it needs to
determine the authorization of the requested grant, including: determine the authorization of the requested grant, including:
* authenticate the RO, through a local account or some other means * authenticate the RO through a local account or some other means,
such as federated login such as federated login
* validate the RO through presentation of claims, attributes, or * validate the RO through presentation of claims, attributes, or
other information other information
* prompt the RO for consent for the requested delegation * prompt the RO for consent for the requested delegation
* describe to the RO what information is being released, to whom, * describe to the RO what information is being released, to whom,
and for what purpose and for what purpose
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* provide the RO with artifacts such as receipts to facilitate an * provide the RO with artifacts such as receipts to facilitate an
audit trail of authorizations audit trail of authorizations
* allow the RO to deny the requested delegation * allow the RO to deny the requested delegation
The AS is also allowed to request authorization from more than one The AS is also allowed to request authorization from more than one
RO, if the AS deems fit. For example, a medical record might need to RO, if the AS deems fit. For example, a medical record might need to
be released by both an attending nurse and a physician, or both be released by both an attending nurse and a physician, or both
owners of a bank account need to sign off on a transfer request. owners of a bank account need to sign off on a transfer request.
Alternatively, the AS could require N of M possible RO's to approve a Alternatively, the AS could require N of M possible ROs to approve a
given request. In some circumstances, the AS could even determine given request. In some circumstances, the AS could even determine
that the end user present during the interaction is not the that the end user present during the interaction is not the
appropriate RO for a given request and reach out to the appropriate appropriate RO for a given request and reach out to the appropriate
RO asynchronously. RO asynchronously.
The RO is also allowed to define an automated policy at the AS to The RO is also allowed to define an automated policy at the AS to
determine which kind of end user can get access to the resource, and determine which kind of end user can get access to the resource and
under which condition. For instance, such a condition might require under which conditions. For instance, such a condition might require
the end user login and the acceptance of the RO's legal provisions. the end user to log in and accept the RO's legal provisions.
Alternatively, client software could be acting without an end user, Alternatively, client software could be acting without an end user,
and the RO's policy allows issuance of access tokens to specific and the RO's policy allows issuance of access tokens to specific
instances of that client software without human interaction. instances of that client software without human interaction.
While all of these cases are supported by GNAP, the details of their While all of these cases are supported by GNAP, the details of their
implementation, and for determining which RO's or related policies implementation, and for determining which ROs or related policies are
are required for a given request, are out of scope for this required for a given request, are out of scope for this
specification. specification.
4.1. Starting Interaction With the End User 4.1. Starting Interaction with the End User
When a grant request is in the _pending_ state, the interaction start When a grant request is in the _pending_ state, the interaction start
methods sent by the client instance can be used to facilitate methods sent by the client instance can be used to facilitate
interaction with the end user. To initiate an interaction start interaction with the end user. To initiate an interaction start
method indicated by the interaction start responses (Section 3.3) method indicated by the interaction start responses (Section 3.3)
from the AS, the client instance follows the steps defined by that from the AS, the client instance follows the steps defined by that
interaction start mode. The actions of the client instance required interaction start mode. The actions of the client instance required
for the interaction start modes defined in this specification are for the interaction start modes defined in this specification are
described in the following sections. Interaction start modes defined described in the following subsections. Interaction start modes
in extensions to this specification MUST define the expected actions defined in extensions to this specification MUST define the expected
of the client software when that interaction start mode is used. actions of the client software when that interaction start mode is
used.
If the client instance does not start an interaction start mode If the client instance does not start an interaction start mode
within an AS-determined amount of time, the AS MUST reject attempts within an AS-determined amount of time, the AS MUST reject attempts
to use the interaction start modes. If the client instance has to use the interaction start modes. If the client instance has
already begun one interaction start mode and the interaction has been already begun one interaction start mode and the interaction has been
successfully completed, the AS MUST reject attempts to use other successfully completed, the AS MUST reject attempts to use other
interaction start modes. For example, if a user code has been interaction start modes. For example, if a user code has been
successfully entered for a grant request, the AS will need to reject successfully entered for a grant request, the AS will need to reject
requests to an arbitrary redirect URI on the same grant request in requests to an arbitrary redirect URI on the same grant request in
order to prevent an attacker from capturing and altering an active order to prevent an attacker from capturing and altering an active
authorization process. authorization process.
4.1.1. Interaction at a Redirected URI 4.1.1. Interaction at a Redirected URI
When the end user is directed to an arbitrary URI through the When the end user is directed to an arbitrary URI through the
"redirect" (Section 3.3.1) mode, the client instance facilitates "redirect" mode (Section 3.3.1), the client instance facilitates
opening the URI through the end user's web browser. The client opening the URI through the end user's web browser. The client
instance could launch the URI through the system browser, provide a instance could launch the URI through the system browser, provide a
clickable link, redirect the user through HTTP response codes, or clickable link, redirect the user through HTTP response codes, or
display the URI in a form the end user can use to launch such as a display the URI in a form the end user can use to launch, such as a
multidimensional barcode. In all cases, the URI is accessed with an multidimensional barcode. In all cases, the URI is accessed with an
HTTP GET request, and the resulting page is assumed to allow direct HTTP GET request, and the resulting page is assumed to allow direct
interaction with the end user through an HTTP user agent. With this interaction with the end user through an HTTP user agent. With this
method, it is common (though not required) for the RO to be the same method, it is common (though not required) for the RO to be the same
party as the end user, since the client instance has to communicate party as the end user, since the client instance has to communicate
the redirection URI to the end user. the redirection URI to the end user.
In many cases, the URI indicates a web page hosted at the AS, In many cases, the URI indicates a web page hosted at the AS,
allowing the AS to authenticate the end user as the RO and allowing the AS to authenticate the end user as the RO and
interactively provide consent. The URI value is used to identify the interactively provide consent. The URI value is used to identify the
grant request being authorized. If the URI cannot be associated with grant request being authorized. If the URI cannot be associated with
a currently active request, the AS MUST display an error to the RO a currently active request, the AS MUST display an error to the RO
and MUST NOT attempt to redirect the RO back to any client instance and MUST NOT attempt to redirect the RO back to any client instance,
even if a redirect finish method is supplied (Section 2.5.2.1). If even if a redirect finish method is supplied (Section 2.5.2.1). If
the URI is not hosted by the AS directly, the means of communication the URI is not hosted by the AS directly, the means of communication
between the AS and the service provided by this URI are out of scope between the AS and the service provided by this URI are out of scope
for this specification. for this specification.
The client instance MUST NOT modify the URI when launching it, in The client instance MUST NOT modify the URI when launching it; in
particular the client instance MUST NOT add any parameters to the particular, the client instance MUST NOT add any parameters to the
URI. The URI MUST be reachable from the end user's browser, though URI. The URI MUST be reachable from the end user's browser, though
the URI MAY be opened on a separate device from the client instance the URI MAY be opened on a separate device from the client instance
itself. The URI MUST be accessible from an HTTP GET request and MUST itself. The URI MUST be accessible from an HTTP GET request and MUST
be protected by HTTPS, be hosted on a server local to the RO's be protected by HTTPS, be hosted on a server local to the RO's
browser ("localhost"), or use an application-specific URI scheme that browser ("localhost"), or use an application-specific URI scheme that
is loaded on the end user's device. is loaded on the end user's device.
4.1.2. Interaction at the Static User Code URI 4.1.2. Interaction at the Static User Code URI
When the end user is directed to enter a short code through the When the end user is directed to enter a short code through the
"user_code" (Section 3.3.3) mode, the client instance communicates "user_code" mode (Section 3.3.3), the client instance communicates
the user code to the end user and directs the end user to enter that the user code to the end user and directs the end user to enter that
code at an associated URI. The client instance MAY format the user code at an associated URI. The client instance MAY format the user
code in such a way as to facilitate memorability and transfer of the code in such a way as to facilitate memorability and transfer of the
code, so long as this formatting does not alter the value as accepted code, so long as this formatting does not alter the value as accepted
at the user code URI. For example, a client instance receiving the at the user code URI. For example, a client instance receiving the
user code "A1BC3DFF" could choose to display this to the user as user code "A1BC3DFF" could choose to display this to the user as
"A1BC 3DFF", breaking up the long string into two shorter strings. "A1BC 3DFF", breaking up the long string into two shorter strings.
When processing input codes, the AS MUST transform the input string When processing input codes, the AS MUST transform the input string
to remove invalid characters. In the above example, the space in to remove invalid characters. In the above example, the space in
between the two parts would be removed upon its entry into the between the two parts would be removed upon its entry into the
interactive form at the user code URI. Additionally, the AS MUST interactive form at the user code URI. Additionally, the AS MUST
treat user input as case insensitive. For example, if the user treat user input as case insensitive. For example, if the user
inputs the string "a1bc 3DFF", the AS will treat the input the same inputs the string "a1bc 3DFF", the AS will treat the input the same
as "A1BC3DFF". To facilitate this, it is RECOMMENDED that the AS use as "A1BC3DFF". To facilitate this, it is RECOMMENDED that the AS use
only ASCII letters and numbers as valid characters for the user code. only ASCII letters and numbers as valid characters for the user code.
It is RECOMMENDED that the AS choose from character values that are It is RECOMMENDED that the AS choose from character values that are
easily copied and typed without ambiguity. For example, some glyphs easily copied and typed without ambiguity. For example, some glyphs
have multiple Unicode code points for the same visual character, and have multiple Unicode code points for the same visual character, and
the end-user could potentially type a different character than what the end user could potentially type a different character than what
the AS has returned. For additional considerations of the AS has returned. For additional considerations of
internationalized character strings, see [RFC8264] internationalized character strings, see [RFC8264].
This mode is designed to be used when the client instance is not able This mode is designed to be used when the client instance is not able
to communicate or facilitate launching an arbitrary URI. The to communicate or facilitate launching an arbitrary URI. The
associated URI could be statically configured with the client associated URI could be statically configured with the client
instance or in the client software's documentation. As a instance or in the client software's documentation. As a
consequence, these URIs SHOULD be short. The user code URI MUST be consequence, these URIs SHOULD be short. The user code URI MUST be
reachable from the end user's browser, though the URI is usually reachable from the end user's browser, though the URI is usually
opened on a separate device from the client instance itself. The URI opened on a separate device from the client instance itself. The URI
MUST be accessible from an HTTP GET request and MUST be protected by MUST be accessible from an HTTP GET request and MUST be protected by
HTTPS, be hosted on a server local to the RO's browser ("localhost"), HTTPS, be hosted on a server local to the RO's browser ("localhost"),
or use an application-specific URI scheme that is loaded on the end or use an application-specific URI scheme that is loaded on the end
user's device. user's device.
In many cases, the URI indicates a web page hosted at the AS, In many cases, the URI indicates a web page hosted at the AS,
allowing the AS to authenticate the end user as the RO and allowing the AS to authenticate the end user as the RO and
interactively provide consent. The value of the user code is used to interactively provide consent. The value of the user code is used to
identify the grant request being authorized. If the user code cannot identify the grant request being authorized. If the user code cannot
be associated with a currently active request, the AS MUST display an be associated with a currently active request, the AS MUST display an
error to the RO and MUST NOT attempt to redirect the RO back to any error to the RO and MUST NOT attempt to redirect the RO back to any
client instance even if a redirect finish method is supplied client instance, even if a redirect finish method is supplied
(Section 2.5.2.1). If the interaction component at the user code URI (Section 2.5.2.1). If the interaction component at the user code URI
is not hosted by the AS directly, the means of communication between is not hosted by the AS directly, the means of communication between
the AS and this URI, including communication of the user code itself, the AS and this URI, including communication of the user code itself,
are out of scope for this specification. are out of scope for this specification.
When the RO enters this code at the user code URI, the AS MUST When the RO enters this code at the user code URI, the AS MUST
uniquely identify the pending request that the code was associated uniquely identify the pending request that the code was associated
with. If the AS does not recognize the entered code, the interaction with. If the AS does not recognize the entered code, the interaction
component MUST display an error to the user. If the AS detects too component MUST display an error to the user. If the AS detects too
many unrecognized code enter attempts, the interaction component many unrecognized code enter attempts, the interaction component
SHOULD display an error to the user indicating too many attempts and SHOULD display an error to the user indicating too many attempts and
MAY take additional actions such as slowing down the input MAY take additional actions such as slowing down the input
interactions. The user should be warned as such an error state is interactions. The user should be warned as such an error state is
approached, if possible. approached, if possible.
4.1.3. Interaction at a Dynamic User Code URI 4.1.3. Interaction at a Dynamic User Code URI
When the end user is directed to enter a short code through the When the end user is directed to enter a short code through the
"user_code_uri" (Section 3.3.4) mode, the client instance "user_code_uri" mode (Section 3.3.4), the client instance
communicates the user code and associated URI to the end user and communicates the user code and associated URI to the end user and
directs the end user to enter that code at the URI. The client directs the end user to enter that code at the URI. The client
instance MAY format the user code in such a way as to facilitate instance MAY format the user code in such a way as to facilitate
memorability and transfer of the code, so long as this formatting memorability and transfer of the code, so long as this formatting
does not alter the value as accepted at the user code URI. For does not alter the value as accepted at the user code URI. For
example, a client instance receiving the user code "A1BC3DFF" could example, a client instance receiving the user code "A1BC3DFF" could
choose to display this to the user as "A1BC 3DFF", breaking up the choose to display this to the user as "A1BC 3DFF", breaking up the
long string into two shorter strings. long string into two shorter strings.
When processing input codes, the AS MUST transform the input string When processing input codes, the AS MUST transform the input string
skipping to change at page 82, line 34 skipping to change at line 3690
and MUST be protected by HTTPS, be hosted on a server local to the and MUST be protected by HTTPS, be hosted on a server local to the
RO's browser ("localhost"), or use an application-specific URI scheme RO's browser ("localhost"), or use an application-specific URI scheme
that is loaded on the end user's device. that is loaded on the end user's device.
In many cases, the URI indicates a web page hosted at the AS, In many cases, the URI indicates a web page hosted at the AS,
allowing the AS to authenticate the end user as the RO and allowing the AS to authenticate the end user as the RO and
interactively provide consent. The value of the user code is used to interactively provide consent. The value of the user code is used to
identify the grant request being authorized. If the user code cannot identify the grant request being authorized. If the user code cannot
be associated with a currently active request, the AS MUST display an be associated with a currently active request, the AS MUST display an
error to the RO and MUST NOT attempt to redirect the RO back to any error to the RO and MUST NOT attempt to redirect the RO back to any
client instance even if a redirect finish method is supplied client instance, even if a redirect finish method is supplied
(Section 2.5.2.1). If the interaction component at the user code URI (Section 2.5.2.1). If the interaction component at the user code URI
is not hosted by the AS directly, the means of communication between is not hosted by the AS directly, the means of communication between
the AS and this URI, including communication of the user code itself, the AS and this URI, including communication of the user code itself,
are out of scope for this specification. are out of scope for this specification.
When the RO enters this code at the given URI, the AS MUST uniquely When the RO enters this code at the given URI, the AS MUST uniquely
identify the pending request that the code was associated with. If identify the pending request that the code was associated with. If
the AS does not recognize the entered code, the interaction component the AS does not recognize the entered code, the interaction component
MUST display an error to the user. If the AS detects too many MUST display an error to the user. If the AS detects too many
unrecognized code enter attempts, the interaction component SHOULD unrecognized code enter attempts, the interaction component SHOULD
display an error to the user indicating too many attempts and MAY display an error to the user indicating too many attempts and MAY
take additional actions such as slowing down the input interactions. take additional actions such as slowing down the input interactions.
The user should be warned as such an error state is approached, if The user should be warned as such an error state is approached, if
possible. possible.
4.1.4. Interaction through an Application URI 4.1.4. Interaction through an Application URI
When the client instance is directed to launch an application through When the client instance is directed to launch an application through
the "app" (Section 3.3.2) mode, the client launches the URI as the "app" mode (Section 3.3.2), the client launches the URI as
appropriate to the system, such as through a deep link or custom URI appropriate to the system, such as through a deep link or custom URI
scheme registered to a mobile application. The means by which the AS scheme registered to a mobile application. The means by which the AS
and the launched application communicate with each other and perform and the launched application communicate with each other and perform
any of the required actions are out of scope for this specification. any of the required actions are out of scope for this specification.
4.2. Post-Interaction Completion 4.2. Post-Interaction Completion
If an interaction "finish" (Section 3.3.5) method is associated with If an interaction "finish" method (Section 3.3.5) is associated with
the current request, the AS MUST follow the appropriate method upon the current request, the AS MUST follow the appropriate method upon
completion of interaction in order to signal the client instance to completion of interaction in order to signal the client instance to
continue, except for some limited error cases discussed below. If a continue, except for some limited error cases discussed below. If a
finish method is not available, the AS SHOULD instruct the RO to finish method is not available, the AS SHOULD instruct the RO to
return to the client instance upon completion. In such cases, it is return to the client instance upon completion. In such cases, it is
expected that the client instance will poll the continuation endpoint expected that the client instance will poll the continuation endpoint
as described in Section 5.2. as described in Section 5.2.
The AS MUST create an interaction reference and associate that The AS MUST create an interaction reference and associate that
reference with the current interaction and the underlying pending reference with the current interaction and the underlying pending
request. The interaction reference value is an ASCII string request. The interaction reference value is an ASCII string
consisting of only unreserved characters per Section 2.3 of consisting of only unreserved characters per Section 2.3 of
[RFC3986]. The interaction reference value MUST be sufficiently [RFC3986]. The interaction reference value MUST be sufficiently
random so as not to be guessable by an attacker. The interaction random so as not to be guessable by an attacker. The interaction
reference MUST be one-time-use to prevent interception and replay reference MUST be one-time-use to prevent interception and replay
attacks. attacks.
The AS MUST calculate a hash value based on the client instance and The AS MUST calculate a hash value based on the client instance, AS
AS nonces and the interaction reference, as described in nonces, and the interaction reference, as described in Section 4.2.3.
Section 4.2.3. The client instance will use this value to validate The client instance will use this value to validate the "finish"
the "finish" call. call.
All interaction finish methods MUST define a way to convey the hash All interaction finish methods MUST define a way to convey the hash
and interaction reference back to the client instance. When an and interaction reference back to the client instance. When an
interaction finish method is used, the client instance MUST present interaction finish method is used, the client instance MUST present
the interaction reference back to the AS as part of its continuation the interaction reference back to the AS as part of its continuation
request (Section 5.1). request (Section 5.1).
Note that in many error cases, such as when the RO has denied access, Note that in many error cases, such as when the RO has denied access,
the "finish" method is still enacted by the AS. This pattern allows the "finish" method is still enacted by the AS. This pattern allows
the client instance to potentially recover from the error state by the client instance to potentially recover from the error state by
modifying its request or providing additional information directly to modifying its request or providing additional information directly to
the AS in a continuation request. The AS MUST NOT follow the the AS in a continuation request. The AS MUST NOT follow the
"finish" method in the following circumstances: "finish" method in the following circumstances:
* The AS has determined that any URIs involved with the finish * The AS has determined that any URIs involved with the finish
method are dangerous or blocked. method are dangerous or blocked.
* The AS cannot determine which ongoing grant request is being * The AS cannot determine which ongoing grant request is being
referenced. referenced.
* The ongoing grant request has been cancelled or otherwise blocked. * The ongoing grant request has been canceled or otherwise blocked.
4.2.1. Completing Interaction with a Browser Redirect to the Callback 4.2.1. Completing Interaction with a Browser Redirect to the Callback
URI URI
When using the redirect interaction finish method defined in When using the redirect interaction finish method defined in Sections
Section 2.5.2.1 and Section 3.3.5, the AS signals to the client 2.5.2.1 and 3.3.5, the AS signals to the client instance that
instance that interaction is complete and the request can be interaction is complete and the request can be continued by directing
continued by directing the RO (in their browser) back to the client the RO (in their browser) back to the client instance's redirect URI.
instance's redirect URI.
The AS secures this redirect by adding the hash and interaction The AS secures this redirect by adding the hash and interaction
reference as query parameters to the client instance's redirect URI. reference as query parameters to the client instance's redirect URI.
hash: The interaction hash value as described in Section 4.2.3. hash: The interaction hash value as described in Section 4.2.3.
REQUIRED. REQUIRED.
interact_ref: The interaction reference generated for this interact_ref: The interaction reference generated for this
interaction. REQUIRED. interaction. REQUIRED.
The means of directing the RO to this URI are outside the scope of The means of directing the RO to this URI are outside the scope of
this specification, but common options include redirecting the RO this specification, but common options include redirecting the RO
from a web page and launching the system browser with the target URI. from a web page and launching the system browser with the target URI.
See Section 13.19 for considerations on which HTTP status code to use See Section 11.19 for considerations on which HTTP status code to use
when redirecting a request that potentially contains credentials. when redirecting a request that potentially contains credentials.
NOTE: '\' line wrapping per RFC 8792 NOTE: '\' line wrapping per RFC 8792
https://client.example.net/return/123455\ https://client.example.net/return/123455\
?hash=x-gguKWTj8rQf7d7i3w3UhzvuJ5bpOlKyAlVpLxBffY\ ?hash=x-gguKWTj8rQf7d7i3w3UhzvuJ5bpOlKyAlVpLxBffY\
&interact_ref=4IFWWIKYBC2PQ6U56NL1 &interact_ref=4IFWWIKYBC2PQ6U56NL1
The client instance MUST be able to process a request on the URI. If The client instance MUST be able to process a request on the URI. If
the URI is HTTP, the request MUST be an HTTP GET. the URI is HTTP, the request MUST be an HTTP GET.
When receiving the request, the client instance MUST parse the query When receiving the request, the client instance MUST parse the query
parameters to extract the hash and interaction reference values. The parameters to extract the hash and interaction reference values. The
client instance MUST calculate and validate the hash value as client instance MUST calculate and validate the hash value as
described in Section 4.2.3. If the hash validates, the client described in Section 4.2.3. If the hash validates, the client
instance sends a continuation request to the AS as described in instance sends a continuation request to the AS as described in
Section 5.1 using the interaction reference value received here. If Section 5.1, using the interaction reference value received here. If
the hash does not validate, the client instance MUST NOT send the the hash does not validate, the client instance MUST NOT send the
interaction reference to the AS. interaction reference to the AS.
4.2.2. Completing Interaction with a Direct HTTP Request Callback 4.2.2. Completing Interaction with a Direct HTTP Request Callback
When using the push interaction finish method defined in When using the push interaction finish method defined in Sections
Section 2.5.2.1 and Section 3.3.5, the AS signals to the client 2.5.2.1 and 3.3.5, the AS signals to the client instance that
instance that interaction is complete and the request can be interaction is complete and the request can be continued by sending
continued by sending an HTTP POST request to the client instance's an HTTP POST request to the client instance's callback URI.
callback URI.
The HTTP message content is a JSON object consisting of the following The HTTP message content is a JSON object consisting of the following
two fields: two fields:
hash (string): The interaction hash value as described in hash (string): The interaction hash value as described in
Section 4.2.3. REQUIRED. Section 4.2.3. REQUIRED.
interact_ref (string) The interaction reference generated for this interact_ref (string): The interaction reference generated for this
interaction. REQUIRED. interaction. REQUIRED.
POST /push/554321 HTTP/1.1 POST /push/554321 HTTP/1.1
Host: client.example.net Host: client.example.net
Content-Type: application/json Content-Type: application/json
{ {
"hash": "pjdHcrti02HLCwGU3qhUZ3wZXt8IjrV_BtE3oUyOuKNk", "hash": "pjdHcrti02HLCwGU3qhUZ3wZXt8IjrV_BtE3oUyOuKNk",
"interact_ref": "4IFWWIKYBC2PQ6U56NL1" "interact_ref": "4IFWWIKYBC2PQ6U56NL1"
} }
Since the AS is making an outbound connection to a URI supplied by an Since the AS is making an outbound connection to a URI supplied by an
outside party (the client instance), the AS MUST protect itself outside party (the client instance), the AS MUST protect itself
against SSRF attacks when making this call as discussed in against Server-Side Request Forgery (SSRF) attacks when making this
Section 13.34. call, as discussed in Section 11.34.
When receiving the request, the client instance MUST parse the JSON When receiving the request, the client instance MUST parse the JSON
object and validate the hash value as described in Section 4.2.3. If object and validate the hash value as described in Section 4.2.3. If
either fails, the client instance MUST return an unknown_interaction either fails, the client instance MUST return an unknown_interaction
error (Section 3.6). If the hash validates, the client instance error (Section 3.6). If the hash validates, the client instance
sends a continuation request to the AS as described in Section 5.1 sends a continuation request to the AS as described in Section 5.1,
using the interaction reference value received here. using the interaction reference value received here.
4.2.3. Calculating the interaction hash 4.2.3. Calculating the Interaction Hash
The "hash" parameter in the request to the client instance's callback The "hash" parameter in the request to the client instance's callback
URI ties the front channel response to an ongoing request by using URI ties the front-channel response to an ongoing request by using
values known only to the parties involved. This security mechanism values known only to the parties involved. This security mechanism
allows the client instance to protect itself against several kinds of allows the client instance to protect itself against several kinds of
session fixation and injection attacks as discussed in Section 13.25 session fixation and injection attacks as discussed in Section 11.25
and related sections. The AS MUST always provide this hash, and the and related sections. The AS MUST always provide this hash, and the
client instance MUST validate the hash when received. client instance MUST validate the hash when received.
To calculate the "hash" value, the party doing the calculation To calculate the "hash" value, the party doing the calculation
creates a hash base string by concatenating the following values in creates a hash base string by concatenating the following values in
the following order using a single newline (0x0A) character to the following order using a single newline (0x0A) character to
separate them: separate them:
* the "nonce" value sent by the client instance in the interaction * the "nonce" value sent by the client instance in the interaction
"finish" section of the initial request (Section 2.5.2) "finish" section of the initial request (Section 2.5.2)
* the AS's nonce value from the interaction finish response * the AS's nonce value from the interaction finish response
(Section 3.3.5) (Section 3.3.5)
* the "interact_ref" returned from the AS as part of the interaction * the "interact_ref" returned from the AS as part of the interaction
finish method (Section 4.2) finish method (Section 4.2)
* the grant endpoint URI the client instance used to make its * the grant endpoint URI the client instance used to make its
initial request (Section 2) initial request (Section 2)
There is no padding or whitespace before or after any of the lines, There is no padding or whitespace before or after any of the lines
and no trailing newline character. The following non-normative and no trailing newline character. The following non-normative
example shows a constructed hash base string consisting of these four example shows a constructed hash base string consisting of these four
elements. elements.
VJLO6A4CATR0KRO VJLO6A4CATR0KRO
MBDOFXG4Y5CVJCX821LH MBDOFXG4Y5CVJCX821LH
4IFWWIKYB2PQ6U56NL1 4IFWWIKYB2PQ6U56NL1
https://server.example.com/tx https://server.example.com/tx
The party then hashes the bytes of the ASCII encoding of this string The party then hashes the bytes of the ASCII encoding of this string
with the appropriate algorithm based on the "hash_method" parameter with the appropriate algorithm based on the "hash_method" parameter
under the "finish" key of the interaction finish request under the "finish" key of the interaction finish request
(Section 2.5.2). The resulting byte array from the hash function is (Section 2.5.2). The resulting byte array from the hash function is
then encoded using URL-Safe Base64 with no padding [RFC4648]. The then encoded using URL-Safe Base64 with no padding [RFC4648]. The
resulting string is the hash value. resulting string is the hash value.
If provided, the "hash_method" value MUST be one of the hash name If provided, the "hash_method" value MUST be one of the hash name
strings defined in the IANA Named Information Hash Algorithm Registry strings defined in the IANA "Named Information Hash Algorithm
[HASH-ALG]. If the "hash_method" value is not present in the client Registry" [HASH-ALG]. If the "hash_method" value is not present in
instance's request, the algorithm defaults to "sha-256". the client instance's request, the algorithm defaults to "sha-256".
For example, the "sha-256" hash method consists of hashing the input For example, the "sha-256" hash method consists of hashing the input
string with the 256-bit SHA2 algorithm. The following is the encoded string with the 256-bit SHA2 algorithm. The following is the encoded
"sha-256" hash of the above example hash base string. "sha-256" hash of the hash base string in the example above.
x-gguKWTj8rQf7d7i3w3UhzvuJ5bpOlKyAlVpLxBffY x-gguKWTj8rQf7d7i3w3UhzvuJ5bpOlKyAlVpLxBffY
For another example, the "sha3-512" hash method consists of hashing As another example, the "sha3-512" hash method consists of hashing
the input string with the 512-bit SHA3 algorithm. The following is the input string with the 512-bit SHA3 algorithm. The following is
the encoded "sha3-512" hash of the above example hash base string. the encoded "sha3-512" hash of the hash base string in the example
above.
NOTE: '\' line wrapping per RFC 8792 NOTE: '\' line wrapping per RFC 8792
pyUkVJSmpqSJMaDYsk5G8WCvgY91l-agUPe1wgn-cc5rUtN69gPI2-S_s-Eswed8iB4\ pyUkVJSmpqSJMaDYsk5G8WCvgY91l-agUPe1wgn-cc5rUtN69gPI2-S_s-Eswed8iB4\
PJ_a5Hg6DNi7qGgKwSQ PJ_a5Hg6DNi7qGgKwSQ
5. Continuing a Grant Request 5. Continuing a Grant Request
While it is possible for the AS to return an approved grant response While it is possible for the AS to return an approved grant response
(Section 3) with all the client instance's requested information (Section 3) with all the client instance's requested information
skipping to change at page 87, line 43 skipping to change at line 3927
The ability to continue an already-started request allows the client The ability to continue an already-started request allows the client
instance to perform several important functions, including presenting instance to perform several important functions, including presenting
additional information from interaction, modifying the initial additional information from interaction, modifying the initial
request, and revoking a grant request in progress. request, and revoking a grant request in progress.
To enable this ongoing negotiation, the AS provides a continuation To enable this ongoing negotiation, the AS provides a continuation
API to the client software. The AS returns a continue field in the API to the client software. The AS returns a continue field in the
response (Section 3.1) that contains information the client instance response (Section 3.1) that contains information the client instance
needs to access this API, including a URI to access as well as a needs to access this API, including a URI to access as well as a
special access token to use during the requests, called the special access token to use during the requests, called the
_continuation access token_. "continuation access token".
All requests to the continuation API are protected by a bound All requests to the continuation API are protected by a bound
continuation access token. The continuation access token is bound to continuation access token. The continuation access token is bound to
the same key and method the client instance used to make the initial the same key and method the client instance used to make the initial
request (or its most recent rotation). As a consequence, when the request (or its most recent rotation). As a consequence, when the
client instance makes any calls to the continuation URI, the client client instance makes any calls to the continuation URI, the client
instance MUST present the continuation access token as described in instance MUST present the continuation access token as described in
Section 7.2 and present proof of the client instance's key (or its Section 7.2 and present proof of the client instance's key (or its
most recent rotation) by signing the request as described in most recent rotation) by signing the request as described in
Section 7.3. The AS MUST validate the signature and ensure that it Section 7.3. The AS MUST validate the signature and ensure that it
is bound to the appropriate key for the continuation access token. is bound to the appropriate key for the continuation access token.
Access tokens other than the continuation access tokens MUST NOT be Access tokens other than the continuation access tokens MUST NOT be
usable for continuation requests. Conversely, continuation access usable for continuation requests. Conversely, continuation access
tokens MUST NOT be usable to make authorized requests to RS's, even tokens MUST NOT be usable to make authorized requests to RSs, even if
if co-located within the AS. co-located within the AS.
In the following non-normative example, the client instance makes a In the following non-normative example, the client instance makes a
POST request to a unique URI and signs the request with HTTP Message POST request to a unique URI and signs the request with HTTP Message
Signatures: Signatures:
POST /continue/KSKUOMUKM HTTP/1.1 POST /continue/KSKUOMUKM HTTP/1.1
Authorization: GNAP 80UPRY5NM33OMUKMKSKU Authorization: GNAP 80UPRY5NM33OMUKMKSKU
Host: server.example.com Host: server.example.com
Content-Length: 0 Content-Length: 0
Signature-Input: sig1=... Signature-Input: sig1=...
skipping to change at page 89, line 17 skipping to change at line 3980
Content-Type: application/json Content-Type: application/json
Authorization: GNAP 80UPRY5NM33OMUKMKSKU Authorization: GNAP 80UPRY5NM33OMUKMKSKU
Signature-Input: sig1=... Signature-Input: sig1=...
Signature: sig1=... Signature: sig1=...
Content-Digest: sha-256=... Content-Digest: sha-256=...
{ {
"interact_ref": "4IFWWIKYBC2PQ6U56NL1" "interact_ref": "4IFWWIKYBC2PQ6U56NL1"
} }
In following non-normative alternative example, the client instance In the following non-normative alternative example, the client
had been provided a continuation URI unique to this ongoing grant instance had been provided a continuation URI unique to this ongoing
request: grant request:
POST /tx/rxgIIEVMBV-BQUO7kxbsp HTTP/1.1 POST /tx/rxgIIEVMBV-BQUO7kxbsp HTTP/1.1
Host: server.example.com Host: server.example.com
Content-Type: application/json Content-Type: application/json
Authorization: GNAP eyJhbGciOiJub25lIiwidHlwIjoiYmFkIn0 Authorization: GNAP eyJhbGciOiJub25lIiwidHlwIjoiYmFkIn0
Signature-Input: sig1=... Signature-Input: sig1=...
Signature: sig1=... Signature: sig1=...
Content-Digest: sha-256=... Content-Digest: sha-256=...
{ {
skipping to change at page 89, line 46 skipping to change at line 4009
If a wait parameter was included in the continuation response If a wait parameter was included in the continuation response
(Section 3.1), the client instance MUST NOT call the continuation URI (Section 3.1), the client instance MUST NOT call the continuation URI
prior to waiting the number of seconds indicated. If no wait period prior to waiting the number of seconds indicated. If no wait period
is indicated, the client instance MUST NOT poll immediately and is indicated, the client instance MUST NOT poll immediately and
SHOULD wait at least 5 seconds. If the client instance does not SHOULD wait at least 5 seconds. If the client instance does not
respect the given wait period, the AS MUST return the too_fast error respect the given wait period, the AS MUST return the too_fast error
(Section 3.6). (Section 3.6).
The response from the AS is a JSON object of a grant response and MAY The response from the AS is a JSON object of a grant response and MAY
contain any of the fields described in Section 3, as described in contain any of the fields described in Section 3, as described in
more detail in the sections below. more detail in the subsections below.
If the AS determines that the client instance can make further If the AS determines that the client instance can make further
requests to the continuation API, the AS MUST include a new requests to the continuation API, the AS MUST include a new
"continue" response (Section 3.1). The new continue response MUST "continue" response (Section 3.1). The new continue response MUST
include a continuation access token as well, and this token SHOULD be include a continuation access token as well, and this token SHOULD be
a new access token, invalidating the previous access token. If the a new access token, invalidating the previous access token. If the
AS does not return a new continue response, the client instance MUST AS does not return a new continue response, the client instance MUST
NOT make an additional continuation request. If a client instance NOT make an additional continuation request. If a client instance
does so, the AS MUST return an invalid_continuation error does so, the AS MUST return an invalid_continuation error
(Section 3.6). (Section 3.6).
For continuation functions that require the client instance to send a For continuation functions that require the client instance to send
message content, the content MUST be a JSON object. message content, the content MUST be a JSON object.
For all requests to the grant continuation API, the AS MAY make use For all requests to the grant continuation API, the AS MAY make use
of long polling mechanisms such as discussed in [RFC6202]. That is of long polling mechanisms such as those discussed in [RFC6202].
to say, instead of returning the current status immediately, the long That is to say, instead of returning the current status immediately,
polling technique allows the AS additional time to process and the long polling technique allows the AS additional time to process
fulfill the request before returning the HTTP response to the client and fulfill the request before returning the HTTP response to the
instance. For example, when the AS receives a continuation request client instance. For example, when the AS receives a continuation
but the grant request is in the _processing_ state, the AS could wait request but the grant request is in the _processing_ state, the AS
until the grant request has moved to the _pending_ or _approved_ could wait until the grant request has moved to the _pending_ or
state before returning the response message. _approved_ state before returning the response message.
5.1. Continuing After a Completed Interaction 5.1. Continuing after a Completed Interaction
When the AS responds to the client instance's finish method as in When the AS responds to the client instance's finish method as in
Section 4.2.1, this response includes an interaction reference. The Section 4.2.1, this response includes an interaction reference. The
client instance MUST include that value as the field interact_ref in client instance MUST include that value as the field interact_ref in
a POST request to the continuation URI. a POST request to the continuation URI.
POST /continue HTTP/1.1 POST /continue HTTP/1.1
Host: server.example.com Host: server.example.com
Content-Type: application/json Content-Type: application/json
Authorization: GNAP 80UPRY5NM33OMUKMKSKU Authorization: GNAP 80UPRY5NM33OMUKMKSKU
skipping to change at page 91, line 6 skipping to change at line 4063
Since the interaction reference is a one-time-use value as described Since the interaction reference is a one-time-use value as described
in Section 4.2.1, if the client instance needs to make additional in Section 4.2.1, if the client instance needs to make additional
continuation calls after this request, the client instance MUST NOT continuation calls after this request, the client instance MUST NOT
include the interaction reference in subsequent calls. If the AS include the interaction reference in subsequent calls. If the AS
detects a client instance submitting an interaction reference when detects a client instance submitting an interaction reference when
the request is not in the _pending_ state, the AS MUST return a the request is not in the _pending_ state, the AS MUST return a
too_many_attempts error (Section 3.6) and SHOULD invalidate the too_many_attempts error (Section 3.6) and SHOULD invalidate the
ongoing request by moving it to the _finalized_ state. ongoing request by moving it to the _finalized_ state.
If the grant request is in the _approved_ state, the grant response If the grant request is in the _approved_ state, the grant response
(Section 3) MAY contain any newly-created access tokens (Section 3.2) (Section 3) MAY contain any newly created access tokens (Section 3.2)
or newly-released subject information (Section 3.4). The response or newly released subject information (Section 3.4). The response
MAY contain a new "continue" response (Section 3.1) as described MAY contain a new "continue" response (Section 3.1) as described
above. The response SHOULD NOT contain any interaction responses above. The response SHOULD NOT contain any interaction responses
(Section 3.3). (Section 3.3).
If the grant request is in the _pending_ state, the grant response If the grant request is in the _pending_ state, the grant response
(Section 3) MUST NOT contain access tokens or subject information, (Section 3) MUST NOT contain access tokens or subject information and
and MAY contain a new interaction responses (Section 3.3) to any MAY contain a new interaction responses (Section 3.3) to any
interaction methods that have not been exhausted at the AS. interaction methods that have not been exhausted at the AS.
For example, if the request is successful in causing the AS to issue For example, if the request is successful in causing the AS to issue
access tokens and release opaque subject claims, the response could access tokens and release opaque subject claims, the response could
look like this: look like this:
NOTE: '\' line wrapping per RFC 8792 NOTE: '\' line wrapping per RFC 8792
{ {
"access_token": { "access_token": {
skipping to change at page 91, line 41 skipping to change at line 4098
} }
}, },
"subject": { "subject": {
"sub_ids": [ { "sub_ids": [ {
"format": "opaque", "format": "opaque",
"id": "J2G8G8O4AZ" "id": "J2G8G8O4AZ"
} ] } ]
} }
} }
With the above example, the client instance can not make an With the above example, the client instance cannot make an additional
additional continuation request because a continue field is not continuation request because a continue field is not included.
included.
In the following non-normative example, the RO has denied the client In the following non-normative example, the RO has denied the client
instance's request and the AS responds with the following response: instance's request, and the AS responds with the following response:
{ {
"error": "user_denied", "error": "user_denied",
"continue": { "continue": {
"access_token": { "access_token": {
"value": "33OMUKMKSKU80UPRY5NM" "value": "33OMUKMKSKU80UPRY5NM"
}, },
"uri": "https://server.example.com/continue", "uri": "https://server.example.com/continue",
"wait": 30 "wait": 30
} }
} }
In the preceding example, the AS includes the continue field in the In the preceding example, the AS includes the continue field in the
response. Therefore, the client instance can continue the grant response. Therefore, the client instance can continue the grant
negotiation process, perhaps modifying the request as discussed in negotiation process, perhaps modifying the request as discussed in
Section 5.3. Section 5.3.
5.2. Continuing During Pending Interaction (Polling) 5.2. Continuing during Pending Interaction (Polling)
When the client instance does not include a finish parameter, the When the client instance does not include a finish parameter, the
client instance will often need to poll the AS until the RO has client instance will often need to poll the AS until the RO has
authorized the request. To do so, the client instance makes a POST authorized the request. To do so, the client instance makes a POST
request to the continuation URI as in Section 5.1, but does not request to the continuation URI as in Section 5.1 but does not
include message content. include message content.
POST /continue HTTP/1.1 POST /continue HTTP/1.1
Host: server.example.com Host: server.example.com
Authorization: GNAP 80UPRY5NM33OMUKMKSKU Authorization: GNAP 80UPRY5NM33OMUKMKSKU
Signature-Input: sig1=... Signature-Input: sig1=...
Signature: sig1=... Signature: sig1=...
If the grant request is in the _approved_ state, the grant response If the grant request is in the _approved_ state, the grant response
(Section 3) MAY contain any newly-created access tokens (Section 3.2) (Section 3) MAY contain any newly created access tokens (Section 3.2)
or newly-released subject claims (Section 3.4). The response MAY or newly released subject claims (Section 3.4). The response MAY
contain a new "continue" response (Section 3.1) as described above. contain a new "continue" response (Section 3.1) as described above.
If a continue field is included, it SHOULD include a wait field to If a continue field is included, it SHOULD include a wait field to
facilitate a reasonable polling rate by the client instance. The facilitate a reasonable polling rate by the client instance. The
response SHOULD NOT contain interaction responses (Section 3.3). response SHOULD NOT contain interaction responses (Section 3.3).
If the grant request is in the _pending_ state, the grant response If the grant request is in the _pending_ state, the grant response
(Section 3) MUST NOT contain access tokens or subject information, (Section 3) MUST NOT contain access tokens or subject information and
and MAY contain a new interaction responses (Section 3.3) to any MAY contain a new interaction responses (Section 3.3) to any
interaction methods that have not been exhausted at the AS. interaction methods that have not been exhausted at the AS.
For example, if the request has not yet been authorized by the RO, For example, if the request has not yet been authorized by the RO,
the AS could respond by telling the client instance to make another the AS could respond by telling the client instance to make another
continuation request in the future. In the following non-normative continuation request in the future. In the following non-normative
example, a new, unique access token has been issued for the call, example, a new, unique access token has been issued for the call,
which the client instance will use in its next continuation request. which the client instance will use in its next continuation request.
{ {
"continue": { "continue": {
skipping to change at page 93, line 39 skipping to change at line 4187
} }
}, },
"subject": { "subject": {
"sub_ids": [ { "sub_ids": [ {
"format": "opaque", "format": "opaque",
"id": "J2G8G8O4AZ" "id": "J2G8G8O4AZ"
} ] } ]
} }
} }
See Section 13.23 for considerations on polling for continuation See Section 11.23 for considerations on polling for continuation
without an interaction finish method. without an interaction finish method.
In error conditions, the AS responds to the client instance with the In error conditions, the AS responds to the client instance with an
error code as discussed in Section 3.6. For example, if the client error code as discussed in Section 3.6. For example, if the client
instance has polled too many times before the RO has approved the instance has polled too many times before the RO has approved the
request, the AS would respond with a message like the following: request, the AS would respond with a message like the following:
{ {
"error": "too_many_attempts" "error": "too_many_attempts"
} }
Since this response does not include a continue section, the client Since this response does not include a continue section, the client
instance cannot continue to poll the AS for additional updates and instance cannot continue to poll the AS for additional updates and
the grant request is _finalized_. If the client instance still needs the grant request is _finalized_. If the client instance still needs
access to the resource, it will need to start with a new grant access to the resource, it will need to start with a new grant
request. request.
5.3. Modifying an Existing Request 5.3. Modifying an Existing Request
The client instance might need to modify an ongoing request, whether The client instance might need to modify an ongoing request,
or not tokens have already been issued or subject information has depending on whether or not tokens have already been issued or
already been released. In such cases, the client instance makes an subject information has already been released. In such cases, the
HTTP PATCH request to the continuation URI and includes any fields it client instance makes an HTTP PATCH request to the continuation URI
needs to modify. Fields that aren't included in the request are and includes any fields it needs to modify. Fields that aren't
considered unchanged from the original request. included in the request are considered unchanged from the original
request.
A grant request associated with a modification request MUST be in the A grant request associated with a modification request MUST be in the
_approved_ or _pending_ state. When the AS receives a valid _approved_ or _pending_ state. When the AS receives a valid
modification request, the AS MUST place the grant request into the modification request, the AS MUST place the grant request into the
_processing_ state and re-evaluate the authorization in the new _processing_ state and re-evaluate the authorization in the new
context created by the update request, since the extent and context context created by the update request, since the extent and context
of the request could have changed. of the request could have changed.
The client instance MAY include the access_token and subject fields The client instance MAY include the access_token and subject fields
as described in Section 2.1 and Section 2.2. Inclusion of these as described in Sections 2.1 and 2.2. Inclusion of these fields
fields override any values in the initial request, which MAY trigger override any values in the initial request, which MAY trigger
additional requirements and policies by the AS. For example, if the additional requirements and policies by the AS. For example, if the
client instance is asking for more access, the AS could require client instance is asking for more access, the AS could require
additional interaction with the RO to gather additional consent. If additional interaction with the RO to gather additional consent. If
the client instance is asking for more limited access, the AS could the client instance is asking for more limited access, the AS could
determine that sufficient authorization has been granted to the determine that sufficient authorization has been granted to the
client instance and return the more limited access rights client instance and return the more limited access rights
immediately. If the grant request was previously in the _approved_ immediately. If the grant request was previously in the _approved_
state, the AS could decide to remember the larger scale of access state, the AS could decide to remember the larger scale of access
rights associated with the grant request, allowing the client rights associated with the grant request, allowing the client
instance to make subsequent requests of different subsets of granted instance to make subsequent requests of different subsets of granted
access. The details of this processing are out of scope for this access. The details of this processing are out of scope for this
specification, but a one possible approach is as follows: specification, but a one possible approach is as follows:
1. A client instance requests access to Foo, and is granted by the 1. A client instance requests access to Foo, and this is granted by
RO. This results in an access token, AT1. the RO. This results in an access token: AT1.
2. The client instance later modifies the grant request to include 2. The client instance later modifies the grant request to include
Foo and Bar together. Since the client instance was previously Foo and Bar together. Since the client instance was previously
granted Foo under this grant request, the RO is prompted to allow granted Foo under this grant request, the RO is prompted to allow
the client instance access to Foo and Bar together. This results the client instance access to Foo and Bar together. This results
in a new access token, AT2 This access token has access to both in a new access token: AT2. This access token has access to both
Foo and Bar. The rights of the original access token AT1 are not Foo and Bar. The rights of the original access token AT1 are not
modified. modified.
3. The client instance makes another grant modification to ask only 3. The client instance makes another grant modification to ask only
for Bar. Since the client instance was previously granted Foo and for Bar. Since the client instance was previously granted Foo and
Bar together under this grant request, the RO is not prompted and Bar together under this grant request, the RO is not prompted,
the access to Bar is granted in a new access token, AT3. This and the access to Bar is granted in a new access token: AT3.
new access token does not allow access to Foo. This new access token does not allow access to Foo.
4. The original access token AT1 expires and the client seeks a new 4. The original access token AT1 expires, and the client seeks a new
access token to replace it. The client instance makes another access token to replace it. The client instance makes another
grant modification to ask only for Foo. Since the client instance grant modification to ask only for Foo. Since the client instance
was previously granted Foo and Bar together under this grant was previously granted Foo and Bar together under this grant
request, the RO is not prompted and the access to Foo is granted request, the RO is not prompted, and the access to Foo is granted
in a new access token, AT4. This new access token does not allow in a new access token: AT4. This new access token does not allow
access to Bar. access to Bar.
All four access tokens are independent of each other and associated All four access tokens are independent of each other and associated
with the same underlying grant request. Each of these access tokens with the same underlying grant request. Each of these access tokens
could possibly also be rotated using token management, if available. could possibly also be rotated using token management, if available.
For example, instead of asking for a new token to replace AT1, the For example, instead of asking for a new token to replace AT1, the
client instance could ask for a refresh of AT1 using the rotation client instance could ask for a refresh of AT1 using the rotation
method of the token management API. This would result in a refreshed method of the token management API. This would result in a refreshed
AT1 with a different token value and expiration from the original AT1 AT1 with a different token value and expiration from the original AT1
but with the same access rights of allowing only access to Foo. but with the same access rights of allowing only access to Foo.
skipping to change at page 95, line 48 skipping to change at line 4292
consistent with any user information previously presented by the consistent with any user information previously presented by the
client instance or otherwise associated with this grant request. client instance or otherwise associated with this grant request.
The client instance MUST NOT include the client section of the The client instance MUST NOT include the client section of the
request, since the client instance is assumed not to have changed. request, since the client instance is assumed not to have changed.
Modification of client instance information, including rotation of Modification of client instance information, including rotation of
keys associated with the client instance, is outside the scope of keys associated with the client instance, is outside the scope of
this specification. this specification.
The client instance MUST NOT include post-interaction responses such The client instance MUST NOT include post-interaction responses such
as described in Section 5.1. as those described in Section 5.1.
Modification requests MUST NOT alter previously-issued access tokens. Modification requests MUST NOT alter previously issued access tokens.
Instead, any access tokens issued from a continuation are considered Instead, any access tokens issued from a continuation are considered
new, separate access tokens. The AS MAY revoke previously-issued new, separate access tokens. The AS MAY revoke previously issued
access tokens after a modification has occurred. access tokens after a modification has occurred.
If the modified request can be granted immediately by the AS (the If the modified request can be granted immediately by the AS (the
grant request is in the _approved_ state), the grant response grant request is in the _approved_ state), the grant response
(Section 3) MAY contain any newly-created access tokens (Section 3.2) (Section 3) MAY contain any newly created access tokens (Section 3.2)
or newly-released subject claims (Section 3.4). The response MAY or newly released subject claims (Section 3.4). The response MAY
contain a new "continue" response (Section 3.1) as described above. contain a new "continue" response (Section 3.1) as described above.
If interaction can occur, the response SHOULD contain interaction If interaction can occur, the response SHOULD contain interaction
responses (Section 3.3) as well. responses (Section 3.3) as well.
For example, a client instance initially requests a set of resources For example, a client instance initially requests a set of resources
using references: using references:
POST /tx HTTP/1.1 POST /tx HTTP/1.1
Host: server.example.com Host: server.example.com
Content-Type: application/json Content-Type: application/json
skipping to change at page 97, line 45 skipping to change at line 4378
{ {
"access_token": { "access_token": {
"access": [ "access": [
"read" "read"
] ]
} }
... ...
} }
The AS replaces the previous access from the first request, allowing The AS replaces the previous access from the first request, allowing
the AS to determine if any previously-granted consent already the AS to determine if any previously granted consent already
applies. In this case, the AS would determine that reducing the applies. In this case, the AS would determine that reducing the
breadth of the requested access means that new access tokens can be breadth of the requested access means that new access tokens can be
issued to the client instance without additional interaction or issued to the client instance without additional interaction or
consent. The AS would likely revoke previously-issued access tokens consent. The AS would likely revoke previously issued access tokens
that had the greater access rights associated with them, unless they that had the greater access rights associated with them, unless they
had been issued with the durable flag. had been issued with the durable flag.
{ {
"continue": { "continue": {
"access_token": { "access_token": {
"value": "M33OMUK80UPRY5NMKSKU" "value": "M33OMUK80UPRY5NMKSKU"
}, },
"uri": "https://server.example.com/continue", "uri": "https://server.example.com/continue",
"wait": 30 "wait": 30
}, },
"access_token": { "access_token": {
"value": "0EVKC7-2ZKwZM_6N760", "value": "0EVKC7-2ZKwZM_6N760",
"access": [ "access": [
"read" "read"
] ]
} }
} }
For another example, the client instance initially requests read-only As another example, the client instance initially requests read-only
access but later needs to step up its access. The initial request access but later needs to step up its access. The initial request
could look like the following HTTP message. could look like the following HTTP message:
POST /tx HTTP/1.1 POST /tx HTTP/1.1
Host: server.example.com Host: server.example.com
Content-Type: application/json Content-Type: application/json
Signature-Input: sig1=... Signature-Input: sig1=...
Signature: sig1=... Signature: sig1=...
Content-Digest: sha-256=... Content-Digest: sha-256=...
{ {
"access_token": { "access_token": {
skipping to change at page 99, line 28 skipping to change at line 4456
} }
} }
This allows the client instance to make an eventual continuation This allows the client instance to make an eventual continuation
call. The client instance later realizes that it now needs "write" call. The client instance later realizes that it now needs "write"
access in addition to the "read" access. Since this is an expansion access in addition to the "read" access. Since this is an expansion
of what it asked for previously, the client instance also includes a of what it asked for previously, the client instance also includes a
new interaction section in case the AS needs to interact with the RO new interaction section in case the AS needs to interact with the RO
again to gather additional authorization. Note that the client again to gather additional authorization. Note that the client
instance's nonce and callback are different from the initial request. instance's nonce and callback are different from the initial request.
Since the original callback was already used in the initial exchange, Since the original callback was already used in the initial exchange
and the callback is intended for one-time-use, a new one needs to be and the callback is intended for one-time use, a new one needs to be
included in order to use the callback again. included in order to use the callback again.
PATCH /continue HTTP/1.1 PATCH /continue HTTP/1.1
Host: server.example.com Host: server.example.com
Content-Type: application/json Content-Type: application/json
Authorization: GNAP 80UPRY5NM33OMUKMKSKU Authorization: GNAP 80UPRY5NM33OMUKMKSKU
Signature-Input: sig1=... Signature-Input: sig1=...
Signature: sig1=... Signature: sig1=...
Content-Digest: sha-256=... Content-Digest: sha-256=...
skipping to change at page 101, line 5 skipping to change at line 4507
place it into the _finalized_ state, the client instance makes an place it into the _finalized_ state, the client instance makes an
HTTP DELETE request to the continuation URI. HTTP DELETE request to the continuation URI.
DELETE /continue HTTP/1.1 DELETE /continue HTTP/1.1
Host: server.example.com Host: server.example.com
Content-Type: application/json Content-Type: application/json
Authorization: GNAP 80UPRY5NM33OMUKMKSKU Authorization: GNAP 80UPRY5NM33OMUKMKSKU
Signature-Input: sig1=... Signature-Input: sig1=...
Signature: sig1=... Signature: sig1=...
If the request is successfully revoked, the AS responds with status If the request is successfully revoked, the AS responds with HTTP
code HTTP 204 (No Content). The AS SHOULD revoke all associated status code 204 (No Content). The AS SHOULD revoke all associated
access tokens, if possible. The AS SHOULD disable all token rotation access tokens, if possible. The AS SHOULD disable all token rotation
and other token management functions on such access tokens, if and other token management functions on such access tokens, if
possible. Once the grant request is in the _finalized_ state, it possible. Once the grant request is in the _finalized_ state, it
MUST NOT be moved to any other state. MUST NOT be moved to any other state.
If the request is not revoked, the AS responds with an If the request is not revoked, the AS responds with an
invalid_continuation error (Section 3.6). invalid_continuation error (Section 3.6).
6. Token Management 6. Token Management
If an access token response includes the manage field as described in If an access token response includes the manage field as described in
Section 3.2.1, the client instance MAY call this URI to manage the Section 3.2.1, the client instance MAY call this URI to manage the
access token with the rotate and revoke actions defined in the access token with the rotate and revoke actions defined in the
following sections. Other actions are undefined by this following subsections. Other actions are undefined by this
specification. specification.
{ {
"access_token": { "access_token": {
"value": "OS9M2PMHKUR64TB8N6BW7OZB8CDFONP219RP1LT0", "value": "OS9M2PMHKUR64TB8N6BW7OZB8CDFONP219RP1LT0",
"flags": ["bearer"], "flags": ["bearer"],
"manage": { "manage": {
"uri": "https://server.example.com/token/PRY5NM33O", "uri": "https://server.example.com/token/PRY5NM33O",
"access_token": { "access_token": {
"value": "B8CDFONP21-4TB8N6.BW7ONM" "value": "B8CDFONP21-4TB8N6.BW7ONM"
} }
} }
} }
} }
The token management access token issued under the manage field is The token management access token issued under the manage field is
used to protect all calls to the token management API. The client used to protect all calls to the token management API. The client
instance MUST present proof of the key associated with the token instance MUST present proof of the key associated with the token
along with the token management access token value. along with the value of the token management access token.
The AS MUST validate the proof and ensure that it is associated with The AS MUST validate the proof and ensure that it is associated with
the token management access token. the token management access token.
The AS MUST uniquely identify the token being managed from the token The AS MUST uniquely identify the token being managed from the token
management URI, the token management access token, or a combination management URI, the token management access token, or a combination
of both. of both.
6.1. Rotating the Access Token Value 6.1. Rotating the Access Token Value
skipping to change at page 102, line 26 skipping to change at line 4571
token in the authorization header as described in Section 7.2 and token in the authorization header as described in Section 7.2 and
signing the request with the appropriate key. signing the request with the appropriate key.
POST /token/PRY5NM33O HTTP/1.1 POST /token/PRY5NM33O HTTP/1.1
Host: server.example.com Host: server.example.com
Authorization: GNAP B8CDFONP21-4TB8N6.BW7ONM Authorization: GNAP B8CDFONP21-4TB8N6.BW7ONM
Signature-Input: sig1=... Signature-Input: sig1=...
Signature: sig1=... Signature: sig1=...
Content-Digest: sha-256=... Content-Digest: sha-256=...
The client instance can not request to alter the access rights The client instance cannot request to alter the access rights
associated with the access token during a rotation request. To get associated with the access token during a rotation request. To get
an access token with different access rights for this grant request, an access token with different access rights for this grant request,
the client instance has to call the continuation API's update the client instance has to call the continuation API's update
(Section 5.3) functionality to get a new access token. The client functionality (Section 5.3) to get a new access token. The client
instance can also create a new grant request with the required access instance can also create a new grant request with the required access
rights. rights.
The AS validates that the token management access token presented is The AS validates that the token management access token presented is
associated with the management URI, that the AS issued the token to associated with the management URI, that the AS issued the token to
the given client instance, and that the presented key is the correct the given client instance, and that the presented key is the correct
key for the token management access token. The AS determines which key for the token management access token. The AS determines which
access token is being rotated from the token management URI, the access token is being rotated from the token management URI, the
token management access token, or both. token management access token, or both.
If the token is validated and the key is appropriate for the request, If the token is validated and the key is appropriate for the request,
the AS MUST invalidate the current access token value associated with the AS MUST invalidate the current access token value associated with
this URI, if possible. Note that stateless access tokens can make this URI, if possible. Note that stateless access tokens can make
proactive revocation difficult within a system, see Section 13.32. proactive revocation difficult within a system; see Section 11.32.
For successful rotations, the AS responds with an HTTP 200 with a For successful rotations, the AS responds with an HTTP 200 with JSON-
JSON-formatted message content consisting of the rotated access token formatted message content consisting of the rotated access token in
in the access_token field described in Section 3.2.1. The value of the access_token field described in Section 3.2.1. The value of the
the access token MUST NOT be the same as the current value of the access token MUST NOT be the same as the current value of the access
access token used to access the management API. The response MUST token used to access the management API. The response MUST include
include an access token management URI, and the value of this URI MAY an access token management URI, and the value of this URI MAY be
be different from the URI used by the client instance to make the different from the URI used by the client instance to make the
rotation call. The client instance MUST use this new URI to manage rotation call. The client instance MUST use this new URI to manage
the rotated access token. the rotated access token.
The access rights in the access array for the rotated access token The access rights in the access array for the rotated access token
MUST be included in the response and MUST be the same as the token MUST be included in the response and MUST be the same as the token
before rotation. before rotation.
NOTE: '\' line wrapping per RFC 8792 NOTE: '\' line wrapping per RFC 8792
{ {
skipping to change at page 104, line 4 skipping to change at line 4638
], ],
"datatypes": [ "datatypes": [
"metadata", "metadata",
"images" "images"
] ]
}, },
"read", "dolphin-metadata" "read", "dolphin-metadata"
] ]
} }
} }
If the AS is unable or unwilling to rotate the value of the access If the AS is unable or unwilling to rotate the value of the access
token, the AS responds with an invalid_rotation error (Section 3.6). token, the AS responds with an invalid_rotation error (Section 3.6).
Upon receiving such an error, the client instance MUST consider the Upon receiving such an error, the client instance MUST consider the
access token to not have changed its state. access token to not have changed its state.
6.1.1. Binding a New Key to the Rotated Access Token 6.1.1. Binding a New Key to the Rotated Access Token
If the client instance wishes to bind a new presentation key to an If the client instance wishes to bind a new presentation key to an
access token, the client instance MUST present both the new key and access token, the client instance MUST present both the new key and
the proof of previous key material in the access token rotation the proof of previous key material in the access token rotation
request. The client instance makes an HTTP POST as a JSON object request. The client instance makes an HTTP POST as a JSON object
with the following field: with the following field:
key: The new key value or reference in the format described in key: The new key value or reference in the format described in
Section 7.1. Note that keys passed by value are always public Section 7.1. Note that keys passed by value are always public
keys. REQUIRED when doing key rotation. keys. REQUIRED when doing key rotation.
The proof method and parameters for the new key MUST be the same as The proof method and parameters for the new key MUST be the same as
those established for the previous key. those established for the previous key.
The client instance MUST prove possession of both the currently-bound The client instance MUST prove possession of both the currently bound
key and the newly-requested key simultaneously in the rotation key and the newly requested key simultaneously in the rotation
request. Specifically, the signature from the previous key MUST request. Specifically, the signature from the previous key MUST
cover the value or reference of the new key, and the signature of the cover the value or reference of the new key, and the signature of the
new key MUST cover the signature value of the old key. The means of new key MUST cover the signature value of the old key. The means of
doing so varies depending on the proofing method in use. For doing so vary depending on the proofing method in use. For example,
example, the HTTP Message Signatures proofing method uses multiple the HTTP Message Signatures proofing method uses multiple signatures
signatures in the request as described in Section 7.3.1.1, as shown in the request as described in Section 7.3.1.1. This is shown in the
in this example. following example.
POST /token/PRY5NM33O HTTP/1.1 POST /token/PRY5NM33O HTTP/1.1
Host: server.example.com Host: server.example.com
Authorization: GNAP B8CDFONP21-4TB8N6.BW7ONM Authorization: GNAP B8CDFONP21-4TB8N6.BW7ONM
Signature-Input: \ Signature-Input: \
sig1=("@method" "@target-uri" "content-digest" \ sig1=("@method" "@target-uri" "content-digest" \
"authorization"),\ "authorization"),\
sig2=("@method" "@target-uri" "content-digest" \ sig2=("@method" "@target-uri" "content-digest" \
"authorization" "signature";key="sig1" \ "authorization" "signature";key="sig1" \
"signature-input";key="sig1") "signature-input";key="sig1")
skipping to change at page 106, line 17 skipping to change at line 4730
with the appropriate key. with the appropriate key.
DELETE /token/PRY5NM33O HTTP/1.1 DELETE /token/PRY5NM33O HTTP/1.1
Host: server.example.com Host: server.example.com
Authorization: GNAP B8CDFONP21-4TB8N6.BW7ONM Authorization: GNAP B8CDFONP21-4TB8N6.BW7ONM
Signature-Input: sig1=... Signature-Input: sig1=...
Signature: sig1=... Signature: sig1=...
If the key presented is associated with the token (or the client If the key presented is associated with the token (or the client
instance, in the case of a bearer token), the AS MUST invalidate the instance, in the case of a bearer token), the AS MUST invalidate the
access token, if possible, and return an HTTP 204 response code. access token, if possible, and return an HTTP response code 204.
204 No Content 204 No Content
Though the AS MAY revoke an access token at any time for any reason, Though the AS MAY revoke an access token at any time for any reason,
the token management function is specifically for the client the token management function is specifically for the client
instance's use. If the access token has already expired or has been instance's use. If the access token has already expired or has been
revoked through other means, the AS SHOULD honor the revocation revoked through other means, the AS SHOULD honor the revocation
request to the token management URI as valid, since the end result is request to the token management URI as valid, since the end result is
still the token not being usable. that the token is still not usable.
7. Securing Requests from the Client Instance 7. Securing Requests from the Client Instance
In GNAP, the client instance secures its requests to an AS and RS by In GNAP, the client instance secures its requests to an AS and RS by
presenting an access token, presenting proof of a key that it presenting an access token, proof of a key that it possesses (aka, a
possesses (aka, a "key proof"), or both an access token and key proof "key proof"), or both an access token and key proof together.
together.
* When an access token is used with a key proof, this is a bound * When an access token is used with a key proof, this is a bound
token request. This type of request is used for calls to the RS token request. This type of request is used for calls to the RS
as well as the AS during grant negotiation. as well as the AS during grant negotiation.
* When a key proof is used with no access token, this is a non- * When a key proof is used with no access token, this is a non-
authorized signed request. This type of request is used for calls authorized signed request. This type of request is used for calls
to the AS to initiate a grant negotiation. to the AS to initiate a grant negotiation.
* When an access token is used with no key proof, this is a bearer * When an access token is used with no key proof, this is a bearer
token request. This type of request is used only for calls to the token request. This type of request is used only for calls to the
RS, and only with access tokens that are not bound to any key as RS and only with access tokens that are not bound to any key as
described in Section 3.2.1. described in Section 3.2.1.
* When neither an access token nor key proof are used, this is an * When neither an access token nor key proof are used, this is an
unsecured request. This type of request is used optionally for unsecured request. This type of request is used optionally for
calls to the RS as part of an RS-first discovery process as calls to the RS as part of an RS-first discovery process as
described in Section 9.1. described in Section 9.1.
7.1. Key Formats 7.1. Key Formats
Several different places in GNAP require the presentation of key Several different places in GNAP require the presentation of key
skipping to change at page 107, line 22 skipping to change at line 4782
All keys are associated with a specific key proofing method. The All keys are associated with a specific key proofing method. The
proofing method associated with the key is indicated using the proof proofing method associated with the key is indicated using the proof
field of the key object. field of the key object.
proof (string or object): The form of proof that the client instance proof (string or object): The form of proof that the client instance
will use when presenting the key. The valid values of this field will use when presenting the key. The valid values of this field
and the processing requirements for each are detailed in and the processing requirements for each are detailed in
Section 7.3. REQUIRED. Section 7.3. REQUIRED.
A key presented by value MUST be a public key and MUST be presented A key presented by value MUST be a public key and MUST be presented
in one and only one supported format, as discussed in Section 13.35. in only one supported format, as discussed in Section 11.35. Note
Note that while most formats present the full value of the public that while most formats present the full value of the public key,
key, some formats present a value cryptographically derived from the some formats present a value cryptographically derived from the
public key. See additional discussion of the presentation of public public key. See additional discussion of the presentation of public
keys in Section 13.7. keys in Section 11.7.
jwk (object): The public key and its properties represented as a jwk (object): The public key and its properties represented as a
JSON Web Key [RFC7517]. A JWK MUST contain the alg (Algorithm) JSON Web Key (JWK) [RFC7517]. A JWK MUST contain the alg
and kid (Key ID) parameters. The alg parameter MUST NOT be (Algorithm) and kid (Key ID) parameters. The alg parameter MUST
"none". The x5c (X.509 Certificate Chain) parameter MAY be used NOT be "none". The x5c (X.509 Certificate Chain) parameter MAY be
to provide the X.509 representation of the provided public key. used to provide the X.509 representation of the provided public
OPTIONAL. key. OPTIONAL.
cert (string): PEM serialized value of the certificate used to sign cert (string): The Privacy-Enhanced Mail (PEM) serialized value of
the request, with optional internal whitespace per [RFC7468]. The the certificate used to sign the request, with optional internal
PEM header and footer are optionally removed. OPTIONAL. whitespace per [RFC7468]. The PEM header and footer are
optionally removed. OPTIONAL.
cert#S256 (string): The certificate thumbprint calculated as per cert#S256 (string): The certificate thumbprint calculated as per
OAuth-MTLS [RFC8705] in base64 URL encoding. Note that this OAuth-MTLS [RFC8705] in base64 URL encoding. Note that this
format does not include the full public key. OPTIONAL. format does not include the full public key. OPTIONAL.
Additional key formats are defined in the GNAP Key Formats Registry Additional key formats can be defined in the "GNAP Key Formats"
(Section 11.17). registry (Section 10.17).
The following non-normative example shows a single key presented in The following non-normative example shows a single key presented in
two different formats. The example key is intended to be used with two different formats. The example key is intended to be used with
the HTTP Message Signatures (Section 7.3.1) proofing mechanism, as the HTTP Message Signatures proofing mechanism (Section 7.3.1), as
indicated by the httpsig value of the proof field. indicated by the httpsig value of the proof field.
As a JSON Web Key: As a JWK:
"key": { "key": {
"proof": "httpsig", "proof": "httpsig",
"jwk": { "jwk": {
"kty": "RSA", "kty": "RSA",
"e": "AQAB", "e": "AQAB",
"kid": "xyz-1", "kid": "xyz-1",
"alg": "RS256", "alg": "RS256",
"n": "kOB5rR4Jv0GMeLaY6_It_r3ORwdf8ci_JtffXyaSx8xY..." "n": "kOB5rR4Jv0GMeLaY6_It_r3ORwdf8ci_JtffXyaSx8xY..."
} }
skipping to change at page 108, line 25 skipping to change at line 4834
As a certificate in PEM format: As a certificate in PEM format:
"key": { "key": {
"proof": "httpsig", "proof": "httpsig",
"cert": "MIIEHDCCAwSgAwIBAgIBATANBgkqhkiG9w0BAQsFA..." "cert": "MIIEHDCCAwSgAwIBAgIBATANBgkqhkiG9w0BAQsFA..."
} }
When the key is presented in GNAP, proof of this key material MUST be When the key is presented in GNAP, proof of this key material MUST be
used to bind the request, the nature of which varies with the used to bind the request, the nature of which varies with the
location in the protocol the key is used. For a key used as part of location in the protocol where the key is used. For a key used as
a client instance's initial request in Section 2.3, the key value part of a client instance's initial request in Section 2.3, the key
represents the client instance's public key, and proof of that key value represents the client instance's public key, and proof of that
MUST be presented in that request. For a key used as part of an key MUST be presented in that request. For a key used as part of an
access token response in Section 3.2.1, the proof of that key MUST be access token response in Section 3.2.1, the proof of that key MUST be
used when the client instance later presents the access token to the used when the client instance later presents the access token to the
RS. RS.
7.1.1. Key References 7.1.1. Key References
Keys in GNAP can also be passed by reference such that the party Keys in GNAP can also be passed by reference such that the party
receiving the reference will be able to determine the appropriate receiving the reference will be able to determine the appropriate
keying material for use in that part of the protocol. Key references keying material for use in that part of the protocol. A key
are a single opaque string. reference is a single opaque string.
"key": "S-P4XJQ_RYJCRTSU1.63N3E" "key": "S-P4XJQ_RYJCRTSU1.63N3E"
Keys referenced in this manner MAY be shared symmetric keys. See the Keys referenced in this manner MAY be shared symmetric keys. See the
additional considerations for symmetric keys in Section 13.7. The additional considerations for symmetric keys in Section 11.7. The
key reference MUST NOT contain any unencrypted private or shared key reference MUST NOT contain any unencrypted private or shared
symmetric key information. symmetric key information.
Keys referenced in this manner MUST be bound to a single proofing Keys referenced in this manner MUST be bound to a single proofing
mechanism. mechanism.
The means of dereferencing this reference to a key value and proofing The means of dereferencing this reference to a key value and proofing
mechanism are out of scope for this specification. Commonly, key mechanism are out of scope for this specification. Commonly, key
references are created by the AS and are not necessarily needed to be references are created by the AS and do not necessarily need to be
understood by the client. These types of key references are an understood by the client. These types of key references are an
internal reference to the AS, such as an identifier of a record in a internal reference to the AS, such as an identifier of a record in a
database. In other applications, it can be useful to use key database. In other applications, it can be useful to use key
references that are resolvable by both clients and AS, which could be references that are resolvable by both clients and the AS, which
accomplished by a client publishing a public key at a URI, for could be accomplished by a client publishing a public key at a URI,
example. For interoperability, this method could later be described for example. For interoperability, this method could later be
as an extension, but doing so is out of scope for this specification. described as an extension, but doing so is out of scope for this
specification.
7.1.2. Key Protection 7.1.2. Key Protection
The security of GNAP relies on the cryptographic security of the keys The security of GNAP relies on the cryptographic security of the keys
themselves. When symmetric keys are used in GNAP, a key management themselves. When symmetric keys are used in GNAP, a key management
system or secure key derivation mechanism MUST be used to supply the system or secure key derivation mechanism MUST be used to supply the
keys. Symmetric keys MUST NOT be a human memorable password or a keys. Symmetric keys MUST NOT be a human-memorable password or a
value derived from one. Symmetric keys MUST NOT be passed by value value derived from one. Symmetric keys MUST NOT be passed by value
from the client instance to the AS. from the client instance to the AS.
Additional security considerations apply when rotating keys Additional security considerations apply when rotating keys (see
(Section 13.22). Section 11.22).
7.2. Presenting Access Tokens 7.2. Presenting Access Tokens
Access tokens are issued to client instances in GNAP to allow the Access tokens are issued to client instances in GNAP to allow the
client instance to make an authorized call to an API. The method the client instance to make an authorized call to an API. The method the
client instance uses to send an access token depends on whether the client instance uses to send an access token depends on whether the
token is bound to a key, and if so which proofing method is token is bound to a key and, if so, which proofing method is
associated with the key. This information is conveyed by the key associated with the key. This information is conveyed by the key
parameter and the bearer flag in the access token response structure parameter and the bearer flag in the access token response structure
(Section 3.2.1). (Section 3.2.1).
If the flags field does not contain the bearer flag and the key is If the flags field does not contain the bearer flag and the key is
absent, the access token MUST be sent using the same key and proofing absent, the access token MUST be sent using the same key and proofing
mechanism that the client instance used in its initial request (or mechanism that the client instance used in its initial request (or
its most recent rotation). its most recent rotation).
If the flags field does not contain the bearer flag and the key value If the flags field does not contain the bearer flag and the key value
skipping to change at page 110, line 20 skipping to change at line 4924
Signature-Input: sig1=("@method" "@target-uri" "authorization")\ Signature-Input: sig1=("@method" "@target-uri" "authorization")\
;created=1618884473;keyid="gnap-rsa";nonce="NAOEJF12ER2";tag="gnap" ;created=1618884473;keyid="gnap-rsa";nonce="NAOEJF12ER2";tag="gnap"
Signature: sig1=:FQ+EjWqc38uLFByKa5y+c4WyYYwCTGUhidWKfr5L1Cha8FiPEw\ Signature: sig1=:FQ+EjWqc38uLFByKa5y+c4WyYYwCTGUhidWKfr5L1Cha8FiPEw\
DxG7nWttpBLS/B6VLfkZJogPbclySs9MDIsAIJwHnzlcJjwXWR2lfvm2z3X7EkJHm\ DxG7nWttpBLS/B6VLfkZJogPbclySs9MDIsAIJwHnzlcJjwXWR2lfvm2z3X7EkJHm\
Zp4SmyKOS34luAiKR1xwf32NYFolHmZf/SbHZJuWvQuS4U33C+BbsXz8MflFH1Dht\ Zp4SmyKOS34luAiKR1xwf32NYFolHmZf/SbHZJuWvQuS4U33C+BbsXz8MflFH1Dht\
H/C1E5i244gSbdLCPxzABc/Q0NHVSLo1qaouYIvnxXB8OT3K7mwWjsLh1GC5vFThb\ H/C1E5i244gSbdLCPxzABc/Q0NHVSLo1qaouYIvnxXB8OT3K7mwWjsLh1GC5vFThb\
3XQ363r6f0OPRa4qWHhubR/d/J/lNOjbBdjq9AJ69oqNJ+A2XT+ZCrVasEJE0OBvD\ 3XQ363r6f0OPRa4qWHhubR/d/J/lNOjbBdjq9AJ69oqNJ+A2XT+ZCrVasEJE0OBvD\
auQoiywhb8BMB7+PEINsPk5/8UvaNxbw==: auQoiywhb8BMB7+PEINsPk5/8UvaNxbw==:
If the flags field contains the bearer flag, the access token is a If the flags field contains the bearer flag, the access token is a
bearer token that MUST be sent using the Authorization Request Header bearer token that MUST be sent using the Authorization request header
Field method defined in [RFC6750]. field method defined in [RFC6750].
Authorization: Bearer OS9M2PMHKUR64TB8N6BW7OZB8CDFONP219RP1LT0 Authorization: Bearer OS9M2PMHKUR64TB8N6BW7OZB8CDFONP219RP1LT0
The Form-Encoded Body Parameter and URI Query Parameter methods of The Form-Encoded Body Parameter and URI Query Parameter methods of
[RFC6750] MUST NOT be used for GNAP access tokens. [RFC6750] MUST NOT be used for GNAP access tokens.
7.3. Proving Possession of a Key with a Request 7.3. Proving Possession of a Key with a Request
Any keys presented by the client instance to the AS or RS MUST be Any keys presented by the client instance to the AS or RS MUST be
validated as part of the request in which they are presented. The validated as part of the request in which they are presented. The
skipping to change at page 110, line 44 skipping to change at line 4948
string, which consists of the key proof method name on its own, or by string, which consists of the key proof method name on its own, or by
a JSON object with the required field method: a JSON object with the required field method:
method: The name of the key proofing method to be used. REQUIRED. method: The name of the key proofing method to be used. REQUIRED.
Individual methods defined as objects MAY define additional Individual methods defined as objects MAY define additional
parameters as members in this object. parameters as members in this object.
Values for the method defined by this specification are as follows: Values for the method defined by this specification are as follows:
"httpsig" (string or object): HTTP Signing signature headers. See "httpsig" (string or object): HTTP signing signature headers. See
Section 7.3.1. Section 7.3.1.
"mtls" (string): Mutual TLS certificate verification. See "mtls" (string): Mutual TLS certificate verification. See
Section 7.3.2. Section 7.3.2.
"jwsd" (string): A detached JWS signature header. See "jwsd" (string): A detached JWS signature header. See
Section 7.3.3. Section 7.3.3.
"jws" (string): Attached JWS payload. See Section 7.3.4. "jws" (string): Attached JWS Payload. See Section 7.3.4.
Additional proofing methods are defined by the GNAP Key Proofing Additional proofing methods can be defined in the "GNAP Key Proofing
Methods Registry (Section 11.16). Methods" registry (Section 10.16).
Proof methods MAY be defined as both an object and a string. For Proof methods MAY be defined as both an object and a string. For
example, the httpsig method can be specified as an object with its example, the httpsig method can be specified as an object with its
parameters explicitly declared, such as: parameters explicitly declared, such as:
{ {
"proof": { "proof": {
"method": "httpsig", "method": "httpsig",
"alg": "ecdsa-p384-sha384", "alg": "ecdsa-p384-sha384",
"content-digest-alg": "sha-256" "content-digest-alg": "sha-256"
skipping to change at page 111, line 40 skipping to change at line 4992
} }
All key binding methods used by this specification MUST cover all All key binding methods used by this specification MUST cover all
relevant portions of the request, including anything that would relevant portions of the request, including anything that would
change the nature of the request, to allow for secure validation of change the nature of the request, to allow for secure validation of
the request. Relevant aspects include the URI being called, the HTTP the request. Relevant aspects include the URI being called, the HTTP
method being used, any relevant HTTP headers and values, and the HTTP method being used, any relevant HTTP headers and values, and the HTTP
message content itself. The verifier of the signed message MUST message content itself. The verifier of the signed message MUST
validate all components of the signed message to ensure that nothing validate all components of the signed message to ensure that nothing
has been tampered with or substituted in a way that would change the has been tampered with or substituted in a way that would change the
nature of the request. Key binding method definitions MUST enumerate nature of the request. Definitions of key binding methods MUST
how these requirements are fulfilled. enumerate how these requirements are fulfilled.
When a key proofing mechanism is bound to an access token, the key When a key proofing mechanism is bound to an access token, the key
being presented MUST be the key associated with the access token and being presented MUST be the key associated with the access token, and
the access token MUST be covered by the signature method of the the access token MUST be covered by the signature method of the
proofing mechanism. proofing mechanism.
The key binding methods in this section MAY be used by other The key binding methods in this section MAY be used by other
components making calls as part of GNAP, such as the extensions components making calls as part of GNAP, such as the extensions
allowing the RS to make calls to the AS defined in allowing the RS to make calls to the AS defined in [GNAP-RS]. To
[I-D.ietf-gnap-resource-servers]. To facilitate this extended use, facilitate this extended use, the sections below are defined in
the sections below are defined in generic terms of the "signer" and generic terms of the "signer" and "verifier" of the HTTP message. In
"verifier" of the HTTP message. In the core functions of GNAP the core functions of GNAP specified in this document, the "signer"
specified in this document, the "signer" is the client instance and is the client instance, and the "verifier" is the AS (for grant
the "verifier" is the AS (for grant requests) or RS (for resource requests) or RS (for resource requests), as appropriate.
requests), as appropriate.
When used for delegation in GNAP, these key binding mechanisms allow When used for delegation in GNAP, these key binding mechanisms allow
the AS to ensure that the keys presented by the client instance in the AS to ensure that the keys presented by the client instance in
the initial request are in control of the party calling any follow-up the initial request are in control of the party calling any follow-up
or continuation requests. To facilitate this requirement, the or continuation requests. To facilitate this requirement, the
continuation response (Section 3.1) includes an access token bound to continuation response (Section 3.1) includes an access token bound to
the client instance's key (Section 2.3), and that key (or its most the client instance's key (Section 2.3), and that key (or its most
recent rotation) MUST be proved in all continuation requests recent rotation) MUST be proved in all continuation requests
(Section 5). Token management requests (Section 6) are similarly (Section 5). Token management requests (Section 6) are similarly
bound to either the access token's own key or, in the case of bearer bound to either the access token's own key or, in the case of bearer
tokens, the client instance's key. tokens, the client instance's key.
In the following sections, unless otherwise noted, the RS256 JOSE In the following subsections, unless otherwise noted, the RS256 JSON
Signature Algorithm (defined in Section 3.3 of [RFC7518]) is applied Object Signing and Encryption (JOSE) signature algorithm (defined in
using the following RSA key (presented here in JWK format): Section 3.3 of [RFC7518]) is applied using the following RSA key
(presented here in JWK format):
NOTE: '\' line wrapping per RFC 8792 NOTE: '\' line wrapping per RFC 8792
{ {
"kid": "gnap-rsa", "kid": "gnap-rsa",
"p": "xS4-YbQ0SgrsmcA7xDzZKuVNxJe3pCYwdAe6efSy4hdDgF9-vhC5gjaRk\ "p": "xS4-YbQ0SgrsmcA7xDzZKuVNxJe3pCYwdAe6efSy4hdDgF9-vhC5gjaRk\
i1wWuERSMW4Tv44l5HNrL-Bbj_nCJxr_HAOaesDiPn2PnywwEfg3Nv95Nn-\ i1wWuERSMW4Tv44l5HNrL-Bbj_nCJxr_HAOaesDiPn2PnywwEfg3Nv95Nn-\
eilhqXRaW-tJKEMjDHu_fmJBeemHNZI412gBnXdGzDVo22dvYoxd6GM", eilhqXRaW-tJKEMjDHu_fmJBeemHNZI412gBnXdGzDVo22dvYoxd6GM",
"kty": "RSA", "kty": "RSA",
"q": "rVdcT_uy-CD0GKVLGpEGRR7k4JO6Tktc8MEHkC6NIFXihk_6vAIOCzCD6\ "q": "rVdcT_uy-CD0GKVLGpEGRR7k4JO6Tktc8MEHkC6NIFXihk_6vAIOCzCD6\
skipping to change at page 113, line 48 skipping to change at line 5068
zywzwPTuq-cVQDyEN7aL0SxCb3Hc4IdqDaMg8qHUyObpPitDQ" zywzwPTuq-cVQDyEN7aL0SxCb3Hc4IdqDaMg8qHUyObpPitDQ"
} }
Key proofing methods SHOULD define a mechanism to allow the rotation Key proofing methods SHOULD define a mechanism to allow the rotation
of keys discussed in Section 6.1.1. Key rotation mechanisms MUST of keys discussed in Section 6.1.1. Key rotation mechanisms MUST
define a way for presenting proof of two keys simultaneously with the define a way for presenting proof of two keys simultaneously with the
following attributes: following attributes:
* The value of or reference to the new key material MUST be signed * The value of or reference to the new key material MUST be signed
by the existing key. Generally speaking, this amounts to using by the existing key. Generally speaking, this amounts to using
the existing key to sign the content of the message which contains the existing key to sign the content of the message that contains
the new key. the new key.
* The signature of the old key MUST be signed by the new key. * The signature of the old key MUST be signed by the new key.
Generally speaking, this means including the signature value of Generally speaking, this means including the signature value of
the old key under the coverage of the new key. the old key under the coverage of the new key.
7.3.1. HTTP Message Signatures 7.3.1. HTTP Message Signatures
This method is indicated by the method value httpsig and can be This method is indicated by the method value httpsig and can be
declared in either object form or string form. declared in either object form or string form.
When the proof method is specified in object form, the following When the proof method is specified in object form, the following
parameters are defined: parameters are defined:
alg: The HTTP signature algorithm, from the HTTP Signature Algorithm alg: The HTTP signature algorithm, from the "HTTP Signature
registry. REQUIRED. Algorithms" registry. REQUIRED.
content-digest-alg: The algorithm used for the Content-Digest field, content-digest-alg: The algorithm used for the Content-Digest field,
used to protect the content when present in the message. used to protect the content when present in the message.
REQUIRED. REQUIRED.
This example uses the ECDSA signing algorithm over the P384 curve and This example uses the Elliptic Curve Digital Signature Algorithm
the SHA-512 hashing algorithm for the content digest. (ECDSA) signing algorithm over the P384 curve and the SHA-512 hashing
algorithm for the content digest.
{ {
"proof": { "proof": {
"method": "httpsig", "method": "httpsig",
"alg": "ecdsa-p384-sha384", "alg": "ecdsa-p384-sha384",
"content-digest-alg": "sha-512" "content-digest-alg": "sha-512"
} }
} }
When the proof method is specified in string form, the signing When the proof method is specified in string form, the signing
skipping to change at page 115, line 34 skipping to change at line 5148
this value. The signer MUST include the created signature parameter this value. The signer MUST include the created signature parameter
with a timestamp of when the signature was created, and the verifier with a timestamp of when the signature was created, and the verifier
MUST ensure that the creation timestamp is sufficiently close to the MUST ensure that the creation timestamp is sufficiently close to the
current time given expected network delay and clock skew. The signer current time given expected network delay and clock skew. The signer
SHOULD include the nonce parameter with a unique and unguessable SHOULD include the nonce parameter with a unique and unguessable
value. When included, the verifier MUST determine that the nonce value. When included, the verifier MUST determine that the nonce
value is unique within a reasonably short time period such as several value is unique within a reasonably short time period such as several
minutes. minutes.
If the signer's key presented is a JWK, the keyid parameter of the If the signer's key presented is a JWK, the keyid parameter of the
signature MUST be set to the kid value of the JWK, the signing signature MUST be set to the kid value of the JWK, and the signing
algorithm used MUST be the JWS algorithm denoted by the key's alg algorithm used MUST be the JWS algorithm denoted by the key's alg
field of the JWK. field of the JWK.
The explicit alg signature parameter MUST NOT be included in the The explicit alg signature parameter MUST NOT be included in the
signature, since the algorithm will be derived either from the key signature, since the algorithm will be derived from either the key
material or from the proof value. material or the proof value.
In the following non-normative example, the message content is the In the following non-normative example, the message content is a JSON
following JSON object: object:
NOTE: '\' line wrapping per RFC 8792 NOTE: '\' line wrapping per RFC 8792
{ {
"access_token": { "access_token": {
"access": [ "access": [
"dolphin-metadata" "dolphin-metadata"
] ]
}, },
"interact": { "interact": {
skipping to change at page 118, line 33 skipping to change at line 5283
} }
The verifier MUST ensure that the signature covers all required The verifier MUST ensure that the signature covers all required
message components. If the HTTP Message includes content, the message components. If the HTTP Message includes content, the
verifier MUST calculate and verify the value of the Content-Digest verifier MUST calculate and verify the value of the Content-Digest
header. The verifier MUST validate the signature against the header. The verifier MUST validate the signature against the
expected key of the signer. expected key of the signer.
A received message MAY include multiple signatures, each with its own A received message MAY include multiple signatures, each with its own
label. The verifier MUST examine all included signatures until it label. The verifier MUST examine all included signatures until it
finds (at least) one that's acceptable according to its policy and finds (at least) one that is acceptable according to its policy and
meets the requirements in this section. meets the requirements in this section.
7.3.1.1. Key Rotation using HTTP Message Signatures 7.3.1.1. Key Rotation Using HTTP Message Signatures
When rotating a key using HTTP Message Signatures, the message, which When rotating a key using HTTP Message Signatures, the message, which
includes the new public key value or reference, is first signed with includes the new public key value or reference, is first signed with
the old key following all of the requirements in Section 7.3.1. The the old key following all of the requirements in Section 7.3.1. The
message is then signed again with the new key by following all of the message is then signed again with the new key by following all of the
requirements in Section 7.3.1 again with the following additional requirements in Section 7.3.1 again, with the following additional
requirements: requirements:
* The covered components MUST include the Signature and Signature- * The covered components MUST include the Signature and Signature-
Input values from the signature generated with the old key Input values from the signature generated with the old key.
* The tag value MUST be gnap-rotate.
* The tag value MUST be gnap-rotate
For example, the following request to the token management endpoint For example, the following request to the token management endpoint
for rotating a token value contains the new key in the request. The for rotating a token value contains the new key in the request. The
message is first signed using the old key and the resulting signature message is first signed using the old key, and the resulting
is placed in "old-key": signature is placed in "old-key":
NOTE: '\' line wrapping per RFC 8792 NOTE: '\' line wrapping per RFC 8792
POST /token/PRY5NM33 HTTP/1.1 POST /token/PRY5NM33 HTTP/1.1
Host: server.example.com Host: server.example.com
Authorization: GNAP 4398.34-12-asvDa.a Authorization: GNAP 4398.34-12-asvDa.a
Content-Digest: sha-512=:Fb/A5vnawhuuJ5xk2RjGrbbxr6cvinZqd4+JPY85u/\ Content-Digest: sha-512=:Fb/A5vnawhuuJ5xk2RjGrbbxr6cvinZqd4+JPY85u/\
JNyTlmRmCOtyVhZ1Oz/cSS4tsYen6fzpCwizy6UQxNBQ==: JNyTlmRmCOtyVhZ1Oz/cSS4tsYen6fzpCwizy6UQxNBQ==:
Signature-Input: old-key=("@method" "@target-uri" "content-digest" \ Signature-Input: old-key=("@method" "@target-uri" "content-digest" \
"authorization");created=1618884475;keyid="test-key-ecc-p256"\ "authorization");created=1618884475;keyid="test-key-ecc-p256"\
skipping to change at page 123, line 40 skipping to change at line 5483
The verifier compares the TLS client certificate presented during The verifier compares the TLS client certificate presented during
mutual TLS negotiation to the expected key of the signer. Since the mutual TLS negotiation to the expected key of the signer. Since the
TLS connection covers the entire message, there are no additional TLS connection covers the entire message, there are no additional
requirements to check. requirements to check.
Note that in many instances, the verifier will not do a full Note that in many instances, the verifier will not do a full
certificate chain validation of the presented TLS client certificate, certificate chain validation of the presented TLS client certificate,
as the means of trust for this certificate could be in something as the means of trust for this certificate could be in something
other than a PKI system, such as a static registration or trust-on- other than a PKI system, such as a static registration or trust-on-
first-use. See Section 13.3 and Section 13.4 for some additional first-use. See Sections 11.3 and 11.4 for some additional
considerations for this key proofing method. considerations for this key proofing method.
7.3.2.1. Key Rotation using MTLS 7.3.2.1. Key Rotation Using MTLS
Since it is not possible to present two client authenticated Since it is not possible to present two client authenticated
certificates to a mutual TLS connection simultaneously, dynamic key certificates to a mutual TLS connection simultaneously, dynamic key
rotation for this proofing method is not defined. Instead, key rotation for this proofing method is not defined. Instead, key
rotation for MTLS-based client instances is expected to be managed rotation for MTLS-based client instances is expected to be managed
through deployment practices, as discussed in Section 13.4. through deployment practices, as discussed in Section 11.4.
7.3.3. Detached JWS 7.3.3. Detached JWS
This method is indicated by the method value jwsd in string form. This method is indicated by the method value jwsd in string form.
{ {
"proof": "jwsd" "proof": "jwsd"
} }
The signer creates a JSON Web Signature (JWS) [RFC7515] object as The signer creates a JSON Web Signature (JWS) [RFC7515] object as
follows: follows.
To protect the request, the JOSE header of the signature contains the To protect the request, the JOSE header of the signature contains the
following claims: following claims:
kid (string): The key identifier. REQUIRED if the key is presented kid (string): The key identifier. REQUIRED if the key is presented
in JWK format, this MUST be the value of the kid field of the key. in JWK format, this MUST be the value of the kid field of the key.
alg (string): The algorithm used to sign the request. MUST be alg (string): The algorithm used to sign the request. MUST be
appropriate to the key presented. If the key is presented as a appropriate to the key presented. If the key is presented as a
JWK, this MUST be equal to the alg parameter of the key. MUST NOT JWK, this MUST be equal to the alg parameter of the key. MUST NOT
be none. REQUIRED. be none. REQUIRED.
typ (string): The type header, value "gnap-binding-jwsd". REQUIRED. typ (string): The type header, value "gnap-binding-jwsd". REQUIRED.
htm (string): The HTTP Method used to make this request, as a case- htm (string): The HTTP method used to make this request, as a case-
sensitive ASCII string. Note that most public HTTP methods are in sensitive ASCII string. Note that most public HTTP methods are in
uppercase ASCII by convention. REQUIRED. uppercase ASCII by convention. REQUIRED.
uri (string): The HTTP URI used for this request. This value MUST uri (string): The HTTP URI used for this request. This value MUST
be an absolute URI, including all path and query components and no be an absolute URI, including all path and query components and no
fragment component. REQUIRED. fragment components. REQUIRED.
created (integer): A timestamp of when the signature was created, in created (integer): A timestamp of when the signature was created, in
integer seconds since UNIX Epoch. REQUIRED. integer seconds since UNIX Epoch. REQUIRED.
When the request is bound to an access token, the JOSE header MUST When the request is bound to an access token, the JOSE header MUST
also include the following: also include the following:
ath (string): The hash of the access token. The value MUST be the ath (string): The hash of the access token. The value MUST be the
result of Base64url encoding (with no padding) the SHA-256 digest result of Base64url encoding (with no padding) the SHA-256 digest
of the ASCII encoding of the associated access token's value. of the ASCII encoding of the associated access token's value.
REQUIRED. REQUIRED.
If the HTTP request has content, such as an HTTP POST or PUT method, If the HTTP request has content (such as an HTTP POST or PUT method),
the payload of the JWS object is the Base64url encoding (without the payload of the JWS object is the Base64url encoding (without
padding) of the SHA256 digest of the bytes of the content. If the padding) of the SHA256 digest of the bytes of the content. If the
request being made does not have content, such as an HTTP GET, request being made does not have content (such as an HTTP GET,
OPTIONS, or DELETE method, the JWS signature is calculated over an OPTIONS, or DELETE method), the JWS signature is calculated over an
empty payload. empty payload.
The signer presents the signed object in compact form [RFC7515] in The signer presents the signed object in compact form [RFC7515] in
the Detached-JWS HTTP Header field. the Detached-JWS header field.
In the following non-normative example, the JOSE Header contains the In the following non-normative example, the JOSE header contains the
following parameters: following parameters:
{ {
"alg": "RS256", "alg": "RS256",
"kid": "gnap-rsa", "kid": "gnap-rsa",
"uri": "https://server.example.com/gnap", "uri": "https://server.example.com/gnap",
"htm": "POST", "htm": "POST",
"typ": "gnap-binding-jwsd", "typ": "gnap-binding-jwsd",
"created": 1618884475 "created": 1618884475
} }
skipping to change at page 126, line 44 skipping to change at line 5600
N7aL0SxCb3Hc4IdqDaMg8qHUyObpPitDQ" N7aL0SxCb3Hc4IdqDaMg8qHUyObpPitDQ"
} }
} }
"display": { "display": {
"name": "My Client Display Name", "name": "My Client Display Name",
"uri": "https://client.foo/" "uri": "https://client.foo/"
}, },
} }
} }
This is hashed to the following Base64 encoded value: This is hashed to the following Base64-encoded value:
PGiVuOZUcN1tRtUS6tx2b4cBgw9mPgXG3IPB3wY7ctc PGiVuOZUcN1tRtUS6tx2b4cBgw9mPgXG3IPB3wY7ctc
This leads to the following full HTTP request message: This leads to the following full HTTP request message:
NOTE: '\' line wrapping per RFC 8792 NOTE: '\' line wrapping per RFC 8792
POST /gnap HTTP/1.1 POST /gnap HTTP/1.1
Host: server.example.com Host: server.example.com
Content-Type: application/json Content-Type: application/json
skipping to change at page 128, line 15 skipping to change at line 5664
"uri": "https://client.foo/" "uri": "https://client.foo/"
}, },
} }
} }
When the verifier receives the Detached-JWS header, it MUST parse and When the verifier receives the Detached-JWS header, it MUST parse and
validate the JWS object. The signature MUST be validated against the validate the JWS object. The signature MUST be validated against the
expected key of the signer. If the HTTP message request contains expected key of the signer. If the HTTP message request contains
content, the verifier MUST calculate the hash of the content just as content, the verifier MUST calculate the hash of the content just as
the signer does, with no normalization or transformation of the the signer does, with no normalization or transformation of the
request. All required fields MUST be present and their values MUST request. All required fields MUST be present, and their values MUST
be valid. All fields MUST match the corresponding portions of the be valid. All fields MUST match the corresponding portions of the
HTTP message. For example, the htm field of the JWS header has to be HTTP message. For example, the htm field of the JWS header has to be
the same as the HTTP verb used in the request. the same as the HTTP verb used in the request.
Note that this proof method depends on a specific cryptographic Note that this proof method depends on a specific cryptographic
algorithm, SHA-256, in two ways: the ath hash algorithm is hardcoded, algorithm, SHA-256, in two ways: the ath hash algorithm is hardcoded,
and computing the payload of the detached/attached signature also and computing the payload of the detached/attached signature also
uses a hardcoded hash. A future version of this document may address uses a hardcoded hash. A future version of this document may address
crypto-agility for both these uses by replacing ath with a new header crypto-agility for both these uses by replacing ath with a new header
that upgrades the algorithm, and possibly defining a new JWS header that upgrades the algorithm and possibly defining a new JWS header
that indicates the HTTP content's hash method. that indicates the HTTP content's hash method.
7.3.3.1. Key Rotation using Detached JWS 7.3.3.1. Key Rotation Using Detached JWS
When rotating a key using Detached JWS, the message, which includes When rotating a key using Detached JWS, the message, which includes
the new public key value or reference, is first signed with the old the new public key value or reference, is first signed with the old
key as described above using a JWS object with typ header value key as described above using a JWS object with typ header value
"gnap-binding-rotation-jwsd". The value of the JWS object is then "gnap-binding-rotation-jwsd". The value of the JWS object is then
taken as the payload of a new JWS object, to be signed by the new key taken as the payload of a new JWS object, to be signed by the new key
using the parameters above. using the parameters above.
The value of the new JWS object is sent in the Detached-JWS header. The value of the new JWS object is sent in the Detached-JWS header.
7.3.4. Attached JWS 7.3.4. Attached JWS
This method is indicated by the method value jws in string form. This method is indicated by the method value jws in string form.
{ {
"proof": "jws" "proof": "jws"
} }
The signer creates a JWS [RFC7515] object as follows: The signer creates a JWS [RFC7515] object as follows.
To protect the request, the JWS header contains the following claims. To protect the request, the JWS header contains the following claims:
kid (string): The key identifier. REQUIRED if the key is presented kid (string): The key identifier. REQUIRED if the key is presented
in JWK format, this MUST be the value of the kid field of the key. in JWK format, this MUST be the value of the kid field of the key.
alg (string): The algorithm used to sign the request. MUST be alg (string): The algorithm used to sign the request. MUST be
appropriate to the key presented. If the key is presented as a appropriate to the key presented. If the key is presented as a
JWK, this MUST be equal to the alg parameter of the key. MUST NOT JWK, this MUST be equal to the alg parameter of the key. MUST NOT
be none. REQUIRED. be none. REQUIRED.
typ (string): The type header, value "gnap-binding-jws". REQUIRED. typ (string): The type header, value "gnap-binding-jws". REQUIRED.
htm (string): The HTTP Method used to make this request, as a case- htm (string): The HTTP method used to make this request, as a case-
sensitive ASCII string. (Note that most public HTTP methods are sensitive ASCII string. (Note that most public HTTP methods are
in uppercase.) REQUIRED. in uppercase.) REQUIRED.
uri (string): The HTTP URI used for this request, including all path uri (string): The HTTP URI used for this request, including all path
and query components and no fragment component. REQUIRED. and query components and no fragment components. REQUIRED.
created (integer): A timestamp of when the signature was created, in created (integer): A timestamp of when the signature was created, in
integer seconds since UNIX Epoch. REQUIRED. integer seconds since UNIX Epoch. REQUIRED.
When the request is bound to an access token, the JOSE header MUST When the request is bound to an access token, the JOSE header MUST
also include the following: also include the following:
ath (string): The hash of the access token. The value MUST be the ath (string): The hash of the access token. The value MUST be the
result of Base64url encoding (with no padding) the SHA-256 digest result of Base64url encoding (with no padding) the SHA-256 digest
of the ASCII encoding of the associated access token's value. of the ASCII encoding of the associated access token's value.
REQUIRED. REQUIRED.
If the HTTP request has content, such as an HTTP POST or PUT method, If the HTTP request has content (such as an HTTP POST or PUT method),
the payload of the JWS object is the JSON serialized content of the the payload of the JWS object is the JSON serialized content of the
request, and the object is signed according to JWS and serialized request, and the object is signed according to JWS and serialized
into compact form [RFC7515]. The signer presents the JWS as the into compact form [RFC7515]. The signer presents the JWS as the
content of the request along with a content type of application/jose. content of the request along with a content type of application/jose.
The verifier MUST extract the payload of the JWS and treat it as the The verifier MUST extract the payload of the JWS and treat it as the
request content for further processing. request content for further processing.
If the request being made does not have content, such as an HTTP GET, If the request being made does not have content (such as an HTTP GET,
OPTIONS, or DELETE method, the JWS signature is calculated over an OPTIONS, or DELETE method), the JWS signature is calculated over an
empty payload and passed in the Detached-JWS header as described in empty payload and passed in the Detached-JWS header as described in
Section 7.3.3. Section 7.3.3.
In the following non-normative example, the JOSE header contains the In the following non-normative example, the JOSE header contains the
following parameters: following parameters:
{ {
"alg": "RS256", "alg": "RS256",
"kid": "gnap-rsa", "kid": "gnap-rsa",
"uri": "https://server.example.com/gnap", "uri": "https://server.example.com/gnap",
skipping to change at page 132, line 44 skipping to change at line 5839
AogICAgfSwKICAgICJzdWJqZWN0IjogewogICAgICAgICJmb3JtYXRzIjogWyJpc3Nf\ AogICAgfSwKICAgICJzdWJqZWN0IjogewogICAgICAgICJmb3JtYXRzIjogWyJpc3Nf\
c3ViIiwgIm9wYXF1ZSJdCiAgICB9Cn0K.MwNoVMQp5hVxI0mCs9LlOUdFtkDXaA1_eT\ c3ViIiwgIm9wYXF1ZSJdCiAgICB9Cn0K.MwNoVMQp5hVxI0mCs9LlOUdFtkDXaA1_eT\
vOXq7DOGrtDKH7q4vP2xUq3fH2jRAZqnobo0WdPP3eM3NH5QUjW8pa6_QpwdIWkK7r-\ vOXq7DOGrtDKH7q4vP2xUq3fH2jRAZqnobo0WdPP3eM3NH5QUjW8pa6_QpwdIWkK7r-\
u_52puE0lPBp7J4U2w4l9gIbg8iknsmWmXeY5F6wiGT8ptfuEYGgmloAJd9LIeNvD3U\ u_52puE0lPBp7J4U2w4l9gIbg8iknsmWmXeY5F6wiGT8ptfuEYGgmloAJd9LIeNvD3U\
LW2h2dz1Pn2eDnbyvgB0Ugae0BoZB4f69fKWj8Z9wvTIjk1LZJN1PcL7_zT8Lrlic9a\ LW2h2dz1Pn2eDnbyvgB0Ugae0BoZB4f69fKWj8Z9wvTIjk1LZJN1PcL7_zT8Lrlic9a\
PyzT7Q9ovkd1s-4whE7TrnGUzFc5mgWUn_gsOpsP5mIIljoEEv-FqOW2RyNYulOZl0Q\ PyzT7Q9ovkd1s-4whE7TrnGUzFc5mgWUn_gsOpsP5mIIljoEEv-FqOW2RyNYulOZl0Q\
8EnnDHV_vPzrHlUarbGg4YffgtwkQhdK72-JOxYQ 8EnnDHV_vPzrHlUarbGg4YffgtwkQhdK72-JOxYQ
When the verifier receives an attached JWS request, it MUST parse and When the verifier receives an attached JWS request, it MUST parse and
validate the JWS object. The signature MUST be validated against the validate the JWS object. The signature MUST be validated against the
expected key of the signer. All required fields MUST be present and expected key of the signer. All required fields MUST be present, and
their values MUST be valid. All fields MUST match the corresponding their values MUST be valid. All fields MUST match the corresponding
portions of the HTTP message. For example, the htm field of the JWS portions of the HTTP message. For example, the htm field of the JWS
header has to be the same as the HTTP verb used in the request. header has to be the same as the HTTP verb used in the request.
Note that this proof method depends on a specific cryptographic Note that this proof method depends on a specific cryptographic
algorithm, SHA-256, in two ways: the ath hash algorithm is hardcoded, algorithm, SHA-256, in two ways: the ath hash algorithm is hardcoded,
and computing the payload of the detached/attached signature also and computing the payload of the detached/attached signature also
uses a hardcoded hash. A future version of this document may address uses a hardcoded hash. A future version of this document may address
crypto-agility for both these uses by replacing ath with a new header crypto-agility for both these uses by replacing ath with a new header
that upgrades the algorithm, and possibly defining a new header that that upgrades the algorithm and possibly defining a new header that
indicates the HTTP content's hash method. indicates the HTTP content's hash method.
7.3.4.1. Key Rotation using Attached JWS 7.3.4.1. Key Rotation Using Attached JWS
When rotating a key using Attached JWS, the message, which includes When rotating a key using Attached JWS, the message, which includes
the new public key value or reference, is first signed with the old the new public key value or reference, is first signed with the old
key using a JWS object with typ header value "gnap-binding-rotation- key using a JWS object with typ header value "gnap-binding-rotation-
jws". The value of the JWS object is then taken as the payload of a jws". The value of the JWS object is then taken as the payload of a
new JWS object, to be signed by the new key. new JWS object, to be signed by the new key.
8. Resource Access Rights 8. Resource Access Rights
GNAP provides a rich structure for describing the protected resources GNAP provides a rich structure for describing the protected resources
hosted by RSs and accessed by client software. This structure is hosted by RSs and accessed by client software. This structure is
used when the client instance requests an access token (Section 2.1) used when the client instance requests an access token (Section 2.1)
and when an access token is returned (Section 3.2). GNAP's structure and when an access token is returned (Section 3.2). GNAP's structure
is designed to be analogous to the OAuth 2.0 Rich Authorization is designed to be analogous to the OAuth 2.0 Rich Authorization
Request data structure defined in [RFC9396]. Requests data structure defined in [RFC9396].
The root of this structure is a JSON array. The elements of the JSON The root of this structure is a JSON array. The elements of the JSON
array represent rights of access that are associated with the access array represent rights of access that are associated with the access
token. Individual rights of access can be defined by the RS as token. Individual rights of access can be defined by the RS as
either an object or a string. The resulting access is the union of either an object or a string. The resulting access is the union of
all elements within the array. all elements within the array.
The access associated with the access token is described using The access associated with the access token is described using
objects that each contain multiple dimensions of access. Each object objects that each contain multiple dimensions of access. Each object
contains a REQUIRED type property that determines the type of API contains a REQUIRED type property that determines the type of API
skipping to change at page 134, line 15 skipping to change at line 5905
While it is expected that many APIs will have their own properties, While it is expected that many APIs will have their own properties,
this specification defines a set of common data fields that are this specification defines a set of common data fields that are
designed to be usable across different types of APIs. This designed to be usable across different types of APIs. This
specification does not require the use of these common fields by an specification does not require the use of these common fields by an
API definition but, instead, provides th