G. Fletcher Verizon Media April 10, 2020 Initiating User Registration via OpenID Connect - draft 03 openid-connect-prompt-create-1_0 Abstract An extension to the OpenID Connect Authentication Framework defining a new value for the "prompt" parameter that instructs the OpenID Provider to start the user flow with user registration and after the user account has been created return an authorization code to the client to complete the authentication flow. Table of Contents 1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 1 2. Requirements Notation and Conventions . . . . . . . . . . . . 2 3. Terminology . . . . . . . . . . . . . . . . . . . . . . . . . 2 4. Prompt Parameter . . . . . . . . . . . . . . . . . . . . . . 2 4.1. Authorization Request . . . . . . . . . . . . . . . . . . 2 5. Security Considerations . . . . . . . . . . . . . . . . . . . 3 6. References . . . . . . . . . . . . . . . . . . . . . . . . . 4 6.1. Normative References . . . . . . . . . . . . . . . . . . 4 6.2. Informative References . . . . . . . . . . . . . . . . . 4 Appendix A. Acknowledgements . . . . . . . . . . . . . . . . . . 5 Appendix B. Notices . . . . . . . . . . . . . . . . . . . . . . 5 Appendix C. Document History . . . . . . . . . . . . . . . . . . 6 Author's Address . . . . . . . . . . . . . . . . . . . . . . . . 6 1. Introduction Several years of deployment and implementation experience with OpenID Connect Core 1.0 [OpenID.Core] has uncovered a need, in some circumstances, for the client to explicitly signal to the OpenID Provider that the user desires to create a new account rather than authenticate an existing identity. This allows the client to indicate to the OpenID Provider that the user desires to create an account. This improves the user experience because the user doesn't have to first see the login form and then find the sign-up link on the form and select it before getting to the user's desired action. This specification defines a new parameter value for the "prompt" parameter. Fletcher Expires October 12, 2020 [Page 1] OIDC Prompt Create April 2020 2. Requirements Notation and Conventions The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT", "SHOULD", "SHOULD NOT", "RECOMMENDED", "NOT RECOMMENDED", "MAY", and "OPTIONAL" in this document are to be interpreted as described in RFC 2119 [RFC2119]. In the .txt version of this specification, values are quoted to indicate that they are to be taken literally. When using these values in protocol messages, the quotes MUST NOT be used as part of the value. In the HTML version of this specification, values to be taken literally are indicated by the use of "this fixed-width font". 3. Terminology This specification uses the terms "authorization endpoint", "authorization request", "authorization response", and "client" defined by The OAuth 2.0 Authorization Framework [RFC6749]. 4. Prompt Parameter In requests to the OpenID Provider, a client MAY indicate that the desired user experience is for the user to immediately see the user account creation UI instead of the login behavior. prompt A value of "create" indicates to the OpenID Provider that the client desires that the user be shown the account creation UX rather than the login flow. Care must be taken if combining this value with other "prompt" values. Mututally exclusive conditions can arise so it is RECOMMENDED that "create" not be present with any other values. 4.1. Authorization Request When the "prompt" parameter is used in an authorization request to the authorization endpoint with the value of "create", it indicates that the user has chosen to be shown the account creation experience rather than the login experience. Whether the AS creates a brand new identity or helps the user authenticate an identity they already have is out of scope for this specification. The behavior is the same for both the implicit flow (Section 3.2 of OpenID Connect Core 1.0 [OpenID.Core]), and the authorization code flow (Section 3.1 of OpenID Connect Core 1.0 [OpenID.Core]). For authorization requests sent as a JWTs, such as when using JWT Secured Authorization Request [I-D.ietf-oauth-jwsreq], the "prompt" Fletcher Expires October 12, 2020 [Page 2] OIDC Prompt Create April 2020 claim value MUST be a space delimited set of prompt values in keeping with Section 3.1.2.1 of OpenID Connect Core 1.0 [OpenID.Core]. How the OpenID Provider handles prompt values that it fails to parse is out of scope for this specification. -or- If the OpenID Provider fails to parse the provided value(s) it should ignore the "prompt" parameter value and proceed as if the "prompt" parameter was not specified. An example of an authorization request where the client tells the OpenID Provider that it wants the user to start from the account creation user experience is shown in Figure 1 below (extra line breaks and indentation are for display purposes only). GET /as/authorization.oauth2?response_type=token &client_id=example-client &state=XzZaJlcwYew1u0QBrRv_Gw &redirect_uri=https%3A%2F%2Fclient%2Eexample%2Eorg%2Fcb &prompt=create &scope=openid%20profile HTTP/1.1 Host: authorization-server.example.com Figure 1: Implicit Flow Authorization Request Below in Figure 2 is an example of an authorization request using the "code" response type where the the client tells the OpenID Provider that it wants the user to start from the account creation user experience (extra line breaks and indentation are for display purposes only). GET /as/authorization.oauth2?response_type=code &client_id=s6BhdRkqt3 &state=tNwzQ87pC6llebpmac_IDeeq-mCR2wLDYljHUZUAWuI &redirect_uri=https%3A%2F%2Fclient%2Eexample%2Eorg%2Fcb &scope=openid%20profile &prompt=create HTTP/1.1 Host: authorization-server.example.com Figure 2: Code Flow Authorization Request 5. Security Considerations Placeholder for now Fletcher Expires October 12, 2020 [Page 3] OIDC Prompt Create April 2020 6. References 6.1. Normative References [OpenID.Core] Sakimura, N., Bradley, J., Jones, M., de Medeiros, B., and C. Mortimore, "OpenID Connect Core 1.0", November 2014, . [RFC2119] Bradner, S., "Key words for use in RFCs to Indicate Requirement Levels", BCP 14, RFC 2119, DOI 10.17487/RFC2119, March 1997, . [RFC3986] Berners-Lee, T., Fielding, R., and L. Masinter, "Uniform Resource Identifier (URI): Generic Syntax", STD 66, RFC 3986, DOI 10.17487/RFC3986, January 2005, . [RFC6749] Hardt, D., Ed., "The OAuth 2.0 Authorization Framework", RFC 6749, DOI 10.17487/RFC6749, October 2012, . [RFC8174] Leiba, B., "Ambiguity of Uppercase vs Lowercase in RFC 2119 Key Words", BCP 14, RFC 8174, DOI 10.17487/RFC8174, May 2017, . 6.2. Informative References [I-D.ietf-oauth-jwsreq] Sakimura, N. and J. Bradley, "The OAuth 2.0 Authorization Framework: JWT Secured Authorization Request (JAR)", draft-ietf-oauth-jwsreq-20 (work in progress), October 2019. [RFC6750] Jones, M. and D. Hardt, "The OAuth 2.0 Authorization Framework: Bearer Token Usage", RFC 6750, DOI 10.17487/RFC6750, October 2012, . [RFC7519] Jones, M., Bradley, J., and N. Sakimura, "JSON Web Token (JWT)", RFC 7519, DOI 10.17487/RFC7519, May 2015, . [RFC7644] Hunt, P., Ed., Grizzle, K., Ansari, M., Wahlstroem, E., and C. Mortimore, "System for Cross-domain Identity Management: Protocol", RFC 7644, DOI 10.17487/RFC7644, September 2015, . Fletcher Expires October 12, 2020 [Page 4] OIDC Prompt Create April 2020 [RFC7662] Richer, J., Ed., "OAuth 2.0 Token Introspection", RFC 7662, DOI 10.17487/RFC7662, October 2015, . Appendix A. Acknowledgements This specification was developed within OpenID connect Working Group of the OpenID Foundation. Additionally, the following individuals contributed ideas, feedback, and wording that helped shape this specification: William Dennis Appendix B. Notices Copyright (c) 2020 The OpenID Foundation. The OpenID Foundation (OIDF) grants to any Contributor, developer, implementer, or other interested party a non-exclusive, royalty free, worldwide copyright license to reproduce, prepare derivative works from, distribute, perform and display, this Implementers Draft or Final Specification solely for the purposes of (i) developing specifications, and (ii) implementing Implementers Drafts and Final Specifications based on such documents, provided that attribution be made to the OIDF as the source of the material, but that such attribution does not indicate an endorsement by the OIDF. The technology described in this specification was made available from contributions from various sources, including members of the OpenID Foundation and others. Although the OpenID Foundation has taken steps to help ensure that the technology is available for distribution, it takes no position regarding the validity or scope of any intellectual property or other rights that might be claimed to pertain to the implementation or use of the technology described in this specification or the extent to which any license under such rights might or might not be available; neither does it represent that it has made any independent effort to identify any such rights. The OpenID Foundation and the contributors to this specification make no (and hereby expressly disclaim any) warranties (express, implied, or otherwise), including implied warranties of merchantability, non- infringement, fitness for a particular purpose, or title, related to this specification, and the entire risk as to implementing this specification is assumed by the implementer. The OpenID Intellectual Property Rights policy requires contributors to offer a patent promise not to assert certain patent claims against other contributors and against implementers. The OpenID Foundation invites any interested party to bring to its attention any copyrights, Fletcher Expires October 12, 2020 [Page 5] OIDC Prompt Create April 2020 patents, patent applications, or other proprietary rights that may cover technology that may be required to practice this specification. Appendix C. Document History [[ To be removed from the final specification ]] -03 o Added OpenID Foundation copyright notice. 2019-10-02 o Incorporated feedback from the working group. Add text around prompt=create being more than a hint but an expectation of an action to be performed. 2019-02-01 o Removed "MUST" normative text and replacec with concept that prompt=create is more of a hint to the OpenID Provider. Author's Address George Fletcher Verizon Media Email: gffletch@aol.com Fletcher Expires October 12, 2020 [Page 6]