NAT.Consulting

nat@nat.consulting https://nat.sakimura.org/

Yubico

ve7jtb@ve7jtb.com http://www.thread-safe.com/

independent

michael_b_jones@hotmail.com https://self-issued.info/

Google

breno@google.com https://stackoverflow.com/users/311376/breno

Disney

charliemortimore@gmail.com https://twitter.com/cmort

OpenID Connect Working Group OpenID Connect 1.0 is a simple identity layer on top of the OAuth 2.0 protocol. It enables Clients to verify the identity of the End-User based on the authentication performed by an Authorization Server, as well as to obtain basic profile information about the End-User in an interoperable and REST-like manner. This specification defines the core OpenID Connect functionality: authentication built on top of OAuth 2.0 and the use of Claims to communicate information about the End-User. It also describes the security and privacy considerations for using OpenID Connect.

OpenID Connect 1.0 is a simple identity layer on top of the OAuth 2.0 protocol. It enables Clients to verify the identity of the End-User based on the authentication performed by an Authorization Server, as well as to obtain basic profile information about the End-User in an interoperable and REST-like manner. The OpenID Connect Core 1.0 specification defines the core OpenID Connect functionality: authentication built on top of OAuth 2.0 and the use of Claims to communicate information about the End-User. It also describes the security and privacy considerations for using OpenID Connect. As background, the OAuth 2.0 Authorization Framework and OAuth 2.0 Bearer Token Usage specifications provide a general framework for third-party applications to obtain and use limited access to HTTP resources. They define mechanisms to obtain and use Access Tokens to access resources but do not define standard methods to provide identity information. Notably, without profiling OAuth 2.0, it is incapable of providing information about the authentication of an End-User. Readers are expected to be familiar with these specifications. OpenID Connect implements authentication as an extension to the OAuth 2.0 authorization process. Use of this extension is requested by Clients by including the openid scope value in the Authorization Request. Information about the authentication performed is returned in a JSON Web Token (JWT) called an ID Token (see ). OAuth 2.0 Authentication Servers implementing OpenID Connect are also referred to as OpenID Providers (OPs). OAuth 2.0 Clients using OpenID Connect are also referred to as Relying Parties (RPs). This specification assumes that the Relying Party has already obtained configuration information about the OpenID Provider, including its Authorization Endpoint and Token Endpoint locations. This information is normally obtained via Discovery, as described in OpenID Connect Discovery 1.0, or may be obtained via other mechanisms. Likewise, this specification assumes that the Relying Party has already obtained sufficient credentials and provided information needed to use the OpenID Provider. This is normally done via Dynamic Registration, as described in OpenID Connect Dynamic Client Registration 1.0, or may be obtained via other mechanisms. The previous versions of this specification are: OpenID Connect Core 1.0 incorporating errata set 1 OpenID Connect Core 1.0 (final)

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. In the .txt version of this document, 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 document, values to be taken literally are indicated by the use of this fixed-width font. All uses of JSON Web Signature (JWS) and JSON Web Encryption (JWE) data structures in this specification utilize the JWS Compact Serialization or the JWE Compact Serialization; the JWS JSON Serialization and the JWE JSON Serialization are not used.

This specification uses the terms "Access Token", "Authorization Code", "Authorization Endpoint", "Authorization Grant", "Authorization Server", "Client", "Client Authentication", "Client Identifier", "Client Secret", "Grant Type", "Protected Resource", "Redirection URI", "Refresh Token", "Resource Owner", "Resource Server", "Response Type", and "Token Endpoint" defined by OAuth 2.0, the terms "Claim Name", "Claim Value", "JSON Web Token (JWT)", "JWT Claims Set", and "Nested JWT" defined by JSON Web Token (JWT), the terms "Base64url Encoding", "Header Parameter", and "JOSE Header" defined by JSON Web Signature (JWS), the term "User Agent" defined by RFC 7230, and the term "Response Mode" defined by OAuth 2.0 Multiple Response Type Encoding Practices. This specification also defines the following terms: Process used to achieve sufficient confidence in the binding between the Entity and the presented Identity. OAuth 2.0 Authorization Request using extension parameters and scopes defined by OpenID Connect to request that the End-User be authenticated by the Authorization Server, which is an OpenID Connect Provider, to the Client, which is an OpenID Connect Relying Party. Information that the Relying Party can require before it makes an entitlement decision with respect to an authentication response. Such context can include, but is not limited to, the actual authentication method used or level of assurance such as ISO/IEC 29115 entity authentication assurance level. Set of authentication methods or procedures that are considered to be equivalent to each other in a particular context. Identifier for an Authentication Context Class. OAuth 2.0 flow in which an Authorization Code is returned from the Authorization Endpoint and all tokens are returned from the Token Endpoint. OAuth 2.0 Authorization Request as defined by . Piece of information asserted about an Entity. Syntax used for representing a Claim Value. This specification defines Normal, Aggregated, and Distributed Claim Types. Server that can return Claims about an Entity. Data presented as evidence of the right to use an identity or other resources. Human participant. Something that has a separate and distinct existence and that can be identified in a context. An End-User is one example of an Entity. Claim specified by the Client as being necessary to ensure a smooth authorization experience for the specific task requested by the End-User. OAuth 2.0 flow in which an Authorization Code is returned from the Authorization Endpoint, some tokens are returned from the Authorization Endpoint, and others are returned from the Token Endpoint. JSON Web Token (JWT) that contains Claims about the Authentication event. It MAY contain other Claims. Value that uniquely characterizes an Entity in a specific context. Set of attributes related to an Entity. OAuth 2.0 flow in which all tokens are returned from the Authorization Endpoint and neither the Token Endpoint nor an Authorization Code are used. Entity that issues a set of Claims. Verifiable Identifier for an Issuer. An Issuer Identifier is a case-sensitive URL using the https scheme that contains scheme, host, and optionally, port number and path components and no query or fragment components. Request or a response between an OpenID Relying Party and an OpenID Provider. OAuth 2.0 Authorization Server that is capable of Authenticating the End-User and providing Claims to a Relying Party about the Authentication event and the End-User. JWT that contains a set of request parameters as its Claims. URL that references a resource containing a Request Object. The Request URI contents MUST be retrievable by the Authorization Server. Identifier that identifies the Entity to a Relying Party that cannot be correlated with the Entity's PPID at another Relying Party. Information that (a) can be used to identify the natural person to whom such information relates, or (b) is or might be directly or indirectly linked to a natural person to whom such information relates. OAuth 2.0 Client application requiring End-User Authentication and Claims from an OpenID Provider. Host component of a URL used by the Relying Party's organization that is an input to the computation of pairwise Subject Identifiers for that Relying Party. Personal, self-hosted OpenID Provider that issues self-signed ID Tokens. Locally unique and never reassigned identifier within the Issuer for the End-User, which is intended to be consumed by the Client. Protected Resource that, when presented with an Access Token by the Client, returns authorized information about the End-User represented by the corresponding Authorization Grant. The UserInfo Endpoint URL MUST use the https scheme and MAY contain port, path, and query parameter components. Process intended to establish the soundness or correctness of a construct. Process intended to test or prove the truth or accuracy of a fact or value. Claim specified by the Client as being useful but not Essential for the specific task requested by the End-User. IMPORTANT NOTE TO READERS: The terminology definitions in this section are a normative portion of this specification, imposing requirements upon implementations. All the capitalized words in the text of this specification, such as "Issuer Identifier", reference these defined terms. Whenever the reader encounters them, their definitions found in this section must be followed. For more background on some of the terminology used, see Internet Security Glossary, Version 2, ISO/IEC 29115 Entity Authentication Assurance, and ITU-T X.1252.

The OpenID Connect protocol, in abstract, follows the following steps. The RP (Client) sends a request to the OpenID Provider (OP). The OP authenticates the End-User and obtains authorization. The OP responds with an ID Token and usually an Access Token. The RP can send a request with the Access Token to the UserInfo Endpoint. The UserInfo Endpoint returns Claims about the End-User.

These steps are illustrated in the following diagram: | | | | | | | | +--------+ | | | | | | | | | | | End- |<--(2) AuthN & AuthZ-->| | | | | User | | | | RP | | | | OP | | | +--------+ | | | | | | | |<--------(3) AuthN Response--------| | | | | | | |---------(4) UserInfo Request----->| | | | | | | |<--------(5) UserInfo Response-----| | | | | | +--------+ +--------+ ]]>

The primary extension that OpenID Connect makes to OAuth 2.0 to enable End-Users to be Authenticated is the ID Token data structure. The ID Token is a security token that contains Claims about the Authentication of an End-User by an Authorization Server when using a Client, and potentially other requested Claims. The ID Token is represented as a JSON Web Token (JWT). The following Claims are used within the ID Token for all OAuth 2.0 flows used by OpenID Connect: REQUIRED. Issuer Identifier for the Issuer of the response. The iss value is a case-sensitive URL using the https scheme that contains scheme, host, and optionally, port number and path components and no query or fragment components. REQUIRED. Subject Identifier. A locally unique and never reassigned identifier within the Issuer for the End-User, which is intended to be consumed by the Client, e.g., 24400320 or AItOawmwtWwcT0k51BayewNvutrJUqsvl6qs7A4. It MUST NOT exceed 255 ASCII characters in length. The sub value is a case-sensitive string. REQUIRED. Audience(s) that this ID Token is intended for. It MUST contain the OAuth 2.0 client_id of the Relying Party as an audience value. It MAY also contain identifiers for other audiences. In the general case, the aud value is an array of case-sensitive strings. In the common special case when there is one audience, the aud value MAY be a single case-sensitive string. REQUIRED. Expiration time on or after which the ID Token MUST NOT be accepted by the RP when performing authentication with the OP. The processing of this parameter requires that the current date/time MUST be before the expiration date/time listed in the value. Implementers MAY provide for some small leeway, usually no more than a few minutes, to account for clock skew. Its value is a JSON number representing the number of seconds from 1970-01-01T00:00:00Z as measured in UTC until the date/time. See RFC 3339 for details regarding date/times in general and UTC in particular. NOTE: The ID Token expiration time is unrelated the lifetime of the authenticated session between the RP and the OP. REQUIRED. Time at which the JWT was issued. Its value is a JSON number representing the number of seconds from 1970-01-01T00:00:00Z as measured in UTC until the date/time. Time when the End-User authentication occurred. Its value is a JSON number representing the number of seconds from 1970-01-01T00:00:00Z as measured in UTC until the date/time. When a max_age request is made or when auth_time is requested as an Essential Claim, then this Claim is REQUIRED; otherwise, its inclusion is OPTIONAL. (The auth_time Claim semantically corresponds to the OpenID 2.0 PAPE auth_time response parameter.) String value used to associate a Client session with an ID Token, and to mitigate replay attacks. The value is passed through unmodified from the Authentication Request to the ID Token. If present in the ID Token, Clients MUST verify that the nonce Claim Value is equal to the value of the nonce parameter sent in the Authentication Request. If present in the Authentication Request, Authorization Servers MUST include a nonce Claim in the ID Token with the Claim Value being the nonce value sent in the Authentication Request. Authorization Servers SHOULD perform no other processing on nonce values used. The nonce value is a case-sensitive string. OPTIONAL. Authentication Context Class Reference. String specifying an Authentication Context Class Reference value that identifies the Authentication Context Class that the authentication performed satisfied. The value "0" indicates the End-User authentication did not meet the requirements of ISO/IEC 29115 level 1. For historic reasons, the value "0" is used to indicate that there is no confidence that the same person is actually there. Authentications with level 0 SHOULD NOT be used to authorize access to any resource of any monetary value. (This corresponds to the OpenID 2.0 PAPE nist_auth_level 0.) An absolute URI or an RFC 6711 registered name SHOULD be used as the acr value; registered names MUST NOT be used with a different meaning than that which is registered. Parties using this claim will need to agree upon the meanings of the values used, which may be context specific. The acr value is a case-sensitive string. OPTIONAL. Authentication Methods References. JSON array of strings that are identifiers for authentication methods used in the authentication. For instance, values might indicate that both password and OTP authentication methods were used. The definition of particular values to be used in the amr Claim is beyond the scope of this specification. Parties using this claim will need to agree upon the meanings of the values used, which may be context specific. The amr value is an array of case-sensitive strings. OPTIONAL. Authorized party - the party to which the ID Token was issued. If present, it MUST contain the OAuth 2.0 Client ID of this party. The azp value is a case-sensitive string containing a StringOrURI value. Note that in practice, the azp Claim only occurs when extensions beyond the scope of this specification are used; therefore, implementations not using such extensions are encouraged to not use azp and to ignore it when it does occur. ID Tokens MAY contain other Claims. Any Claims used that are not understood MUST be ignored. See Sections , , , and for additional Claims defined by this specification. ID Tokens MUST be signed using JWS and optionally both signed and then encrypted using JWS and JWE respectively, thereby providing authentication, integrity, non-repudiation, and optionally, confidentiality, per . If the ID Token is encrypted, it MUST be signed then encrypted, with the result being a Nested JWT, as defined in . ID Tokens MUST NOT use none as the alg value unless the Response Type used returns no ID Token from the Authorization Endpoint (such as when using the Authorization Code Flow) and the Client explicitly requested the use of none at Registration time. ID Tokens SHOULD NOT use the JWS or JWE x5u, x5c, jku, or jwk Header Parameter fields. Instead, references to keys used are communicated in advance using Discovery and Registration parameters, per .

The following is a non-normative example of the set of Claims (the JWT Claims Set) in an ID Token:

OpenID Connect performs authentication to log in the End-User or to determine that the End-User is already logged in. OpenID Connect returns the result of the Authentication performed by the Server to the Client in a secure manner so that the Client can rely on it. For this reason, the Client is called Relying Party (RP) in this case. The Authentication result is returned in an ID Token, as defined in . It has Claims expressing such information as the Issuer, the Subject Identifier, when the authentication was performed, etc. Authentication can follow one of three paths: the Authorization Code Flow (response_type=code), the Implicit Flow (response_type=id_token token or response_type=id_token), or the Hybrid Flow (using other Response Type values defined in OAuth 2.0 Multiple Response Type Encoding Practices). The flows determine how the ID Token and Access Token are returned to the Client. The characteristics of the three flows are summarized in the following non-normative table. The table is intended to provide some guidance on which flow to choose in particular contexts. Property Authorization Code Flow Implicit Flow Hybrid Flow All tokens returned from Authorization Endpoint no yes no All tokens returned from Token Endpoint yes no no Tokens not revealed to User Agent yes no no Client can be authenticated yes no yes Refresh Token possible yes no yes Communication in one round trip no yes no Most communication server-to-server yes no varies The flow used is determined by the response_type value contained in the Authorization Request. These response_type values select these flows: "response_type" value Flow code Authorization Code Flow id_token Implicit Flow id_token token Implicit Flow code id_token Hybrid Flow code token Hybrid Flow code id_token token Hybrid Flow All but the code Response Type value, which is defined by OAuth 2.0, are defined in the OAuth 2.0 Multiple Response Type Encoding Practices specification. NOTE: While OAuth 2.0 also defines the token Response Type value for the Implicit Flow, OpenID Connect does not use this Response Type, since no ID Token would be returned.

This section describes how to perform authentication using the Authorization Code Flow. When using the Authorization Code Flow, all tokens are returned from the Token Endpoint. The Authorization Code Flow returns an Authorization Code to the Client, which can then exchange it for an ID Token and an Access Token directly. This provides the benefit of not exposing any tokens to the User Agent and possibly other malicious applications with access to the User Agent. The Authorization Server can also authenticate the Client before exchanging the Authorization Code for an Access Token. The Authorization Code flow is suitable for Clients that can securely maintain a Client Secret between themselves and the Authorization Server.

The Authorization Code Flow goes through the following steps. Client prepares an Authentication Request containing the desired request parameters. Client sends the request to the Authorization Server. Authorization Server Authenticates the End-User. Authorization Server obtains End-User Consent/Authorization. Authorization Server sends the End-User back to the Client with an Authorization Code. Client requests a response using the Authorization Code at the Token Endpoint. Client receives a response that contains an ID Token and Access Token in the response body. Client validates the ID token and retrieves the End-User's Subject Identifier.

The Authorization Endpoint performs Authentication of the End-User. This is done by sending the User Agent to the Authorization Server's Authorization Endpoint for Authentication and Authorization, using request parameters defined by OAuth 2.0 and additional parameters and parameter values defined by OpenID Connect. Communication with the Authorization Endpoint MUST utilize TLS. See for more information on using TLS.

An Authentication Request is an OAuth 2.0 Authorization Request that requests that the End-User be authenticated by the Authorization Server. Authorization Servers MUST support the use of the HTTP GET and POST methods defined in RFC 7231 at the Authorization Endpoint. Clients MAY use the HTTP GET or POST methods to send the Authorization Request to the Authorization Server. If using the HTTP GET method, the request parameters are serialized using URI Query String Serialization, per . If using the HTTP POST method, the request parameters are serialized using Form Serialization, per . OpenID Connect uses the following OAuth 2.0 request parameters with the Authorization Code Flow: REQUIRED. OpenID Connect requests MUST contain the openid scope value. If the openid scope value is not present, the behavior is entirely unspecified. Other scope values MAY be present. Scope values used that are not understood by an implementation SHOULD be ignored. See Sections and for additional scope values defined by this specification. REQUIRED. OAuth 2.0 Response Type value that determines the authorization processing flow to be used, including what parameters are returned from the endpoints used. When using the Authorization Code Flow, this value is code. REQUIRED. OAuth 2.0 Client Identifier valid at the Authorization Server. REQUIRED. Redirection URI to which the response will be sent. This URI MUST exactly match one of the Redirection URI values for the Client pre-registered at the OpenID Provider, with the matching performed as described in Section 6.2.1 of (Simple String Comparison). When using this flow, the Redirection URI SHOULD use the https scheme; however, it MAY use the http scheme, provided that the Client Type is confidential, as defined in Section 2.1 of OAuth 2.0, and provided the OP allows the use of http Redirection URIs in this case. The Redirection URI MAY use an alternate scheme, such as one that is intended to identify a callback into a native application. RECOMMENDED. Opaque value used to maintain state between the request and the callback. Typically, Cross-Site Request Forgery (CSRF, XSRF) mitigation is done by cryptographically binding the value of this parameter with a browser cookie. OpenID Connect also uses the following OAuth 2.0 request parameter, which is defined in OAuth 2.0 Multiple Response Type Encoding Practices: OPTIONAL. Informs the Authorization Server of the mechanism to be used for returning parameters from the Authorization Endpoint. This use of this parameter is NOT RECOMMENDED when the Response Mode that would be requested is the default mode specified for the Response Type. This specification also defines the following request parameters: OPTIONAL. String value used to associate a Client session with an ID Token, and to mitigate replay attacks. The value is passed through unmodified from the Authentication Request to the ID Token. Sufficient entropy MUST be present in the nonce values used to prevent attackers from guessing values. For implementation notes, see . OPTIONAL. ASCII string value that specifies how the Authorization Server displays the authentication and consent user interface pages to the End-User. The defined values are: The Authorization Server SHOULD display the authentication and consent UI consistent with a full User Agent page view. If the display parameter is not specified, this is the default display mode. The Authorization Server SHOULD display the authentication and consent UI consistent with a popup User Agent window. The popup User Agent window should be of an appropriate size for a login-focused dialog and should not obscure the entire window that it is popping up over. The Authorization Server SHOULD display the authentication and consent UI consistent with a device that leverages a touch interface. The Authorization Server SHOULD display the authentication and consent UI consistent with a "feature phone" type display. The Authorization Server MAY also attempt to detect the capabilities of the User Agent and present an appropriate display. If an OP receives a display value outside the set defined above that it does not understand, it MAY return an error or it MAY ignore it; in practice, not returning errors for not-understood values will help facilitate phasing in extensions using new display values. OPTIONAL. Space-delimited, case-sensitive list of ASCII string values that specifies whether the Authorization Server prompts the End-User for reauthentication and consent. The defined values are: The Authorization Server MUST NOT display any authentication or consent user interface pages. An error is returned if an End-User is not already authenticated or the Client does not have pre-configured consent for the requested Claims or does not fulfill other conditions for processing the request. The error code will typically be login_required, interaction_required, or another code defined in . This can be used as a method to check for existing authentication and/or consent. The Authorization Server SHOULD prompt the End-User for reauthentication. If it cannot reauthenticate the End-User, it MUST return an error, typically login_required. The Authorization Server SHOULD prompt the End-User for consent before returning information to the Client. If it cannot obtain consent, it MUST return an error, typically consent_required. The Authorization Server SHOULD prompt the End-User to select a user account. This enables an End-User who has multiple accounts at the Authorization Server to select amongst the multiple accounts that they might have current sessions for. If it cannot obtain an account selection choice made by the End-User, it MUST return an error, typically account_selection_required. The prompt parameter can be used by the Client to make sure that the End-User is still present for the current session or to bring attention to the request. If this parameter contains none with any other value, an error is returned. If an OP receives a prompt value outside the set defined above that it does not understand, it MAY return an error or it MAY ignore it; in practice, not returning errors for not-understood values will help facilitate phasing in extensions using new prompt values. OPTIONAL. Maximum Authentication Age. Specifies the allowable elapsed time in seconds since the last time the End-User was actively authenticated by the OP. If the elapsed time is greater than this value, the OP MUST attempt to actively re-authenticate the End-User. (The max_age request parameter corresponds to the OpenID 2.0 PAPE max_auth_age request parameter.) When max_age is used, the ID Token returned MUST include an auth_time Claim Value. Note that max_age=0 is equivalent to prompt=login. OPTIONAL. End-User's preferred languages and scripts for the user interface, represented as a space-separated list of BCP47 language tag values, ordered by preference. For instance, the value "fr-CA fr en" represents a preference for French as spoken in Canada, then French (without a region designation), followed by English (without a region designation). An error SHOULD NOT result if some or all of the requested locales are not supported by the OpenID Provider. OPTIONAL. ID Token previously issued by the Authorization Server being passed as a hint about the End-User's current or past authenticated session with the Client. If the End-User identified by the ID Token is already logged in or is logged in as a result of the request (with the OP possibly evaluating other information beyond the ID Token in this decision), then the Authorization Server returns a positive response; otherwise, it MUST return an error, such as login_required. When possible, an id_token_hint SHOULD be present when prompt=none is used and an invalid_request error MAY be returned if it is not; however, the server SHOULD respond successfully when possible, even if it is not present. The Authorization Server need not be listed as an audience of the ID Token when it is used as an id_token_hint value. If the ID Token received by the RP from the OP is encrypted, to use it as an id_token_hint, the Client MUST decrypt the signed ID Token contained within the encrypted ID Token. The Client MAY re-encrypt the signed ID token to the Authentication Server using a key that enables the server to decrypt the ID Token, and use the re-encrypted ID token as the id_token_hint value. OPTIONAL. Hint to the Authorization Server about the login identifier the End-User might use to log in (if necessary). This hint can be used by an RP if it first asks the End-User for their e-mail address (or other identifier) and then wants to pass that value as a hint to the discovered authorization service. It is RECOMMENDED that the hint value match the value used for discovery. This value MAY also be a phone number in the format specified for the phone_number Claim. The use of this parameter is left to the OP's discretion. OPTIONAL. Requested Authentication Context Class Reference values. Space-separated string that specifies the acr values that the Authorization Server is being requested to use for processing this Authentication Request, with the values appearing in order of preference. The Authentication Context Class satisfied by the authentication performed is returned as the acr Claim Value, as specified in . The acr Claim is requested as a Voluntary Claim by this parameter. Other parameters MAY be sent. See Sections , , , , , and for additional Authorization Request parameters and parameter values defined by this specification.

The following is a non-normative example HTTP 302 redirect response by the Client, which triggers the User Agent to make an Authentication Request to the Authorization Endpoint (with line wraps within values for display purposes only):

The following is the non-normative example request that would be sent by the User Agent to the Authorization Server in response to the HTTP 302 redirect response by the Client above (with line wraps within values for display purposes only):

The Authorization Server MUST validate the request received as follows: The Authorization Server MUST validate all the OAuth 2.0 parameters according to the OAuth 2.0 specification. Verify that a scope parameter is present and contains the openid scope value. (If no openid scope value is present, the request may still be a valid OAuth 2.0 request, but is not an OpenID Connect request.) The Authorization Server MUST verify that all the REQUIRED parameters are present and their usage conforms to this specification. If the sub (subject) Claim is requested with a specific value for the ID Token, the Authorization Server MUST only send a positive response if the End-User identified by that sub value has an active session with the Authorization Server or has been Authenticated as a result of the request. The Authorization Server MUST NOT reply with an ID Token or Access Token for a different user, even if they have an active session with the Authorization Server. Such a request can be made either using an id_token_hint parameter or by requesting a specific Claim Value as described in , if the claims parameter is supported by the implementation. When an id_token_hint is present, the OP MUST validate that it was the issuer of the ID Token. The OP SHOULD accept ID Tokens when the RP identified by the ID Token has a current session or had a recent session at the OP, even when the exp time has passed. As specified in OAuth 2.0, Authorization Servers SHOULD ignore unrecognized request parameters. If the Authorization Server encounters any error, it MUST return an error response, per .

If the request is valid, the Authorization Server attempts to Authenticate the End-User or determines whether the End-User is Authenticated, depending upon the request parameter values used. The methods used by the Authorization Server to Authenticate the End-User (e.g. username and password, session cookies, etc.) are beyond the scope of this specification. An Authentication user interface MAY be displayed by the Authorization Server, depending upon the request parameter values used and the authentication methods used. The Authorization Server MUST attempt to Authenticate the End-User in the following cases: The End-User is not already Authenticated. The Authentication Request contains the prompt parameter with the value login. In this case, the Authorization Server MUST reauthenticate the End-User even if the End-User is already authenticated. The Authorization Server MUST NOT interact with the End-User in the following case: The Authentication Request contains the prompt parameter with the value none. In this case, the Authorization Server MUST return an error if an End-User is not already Authenticated or could not be silently Authenticated. When interacting with the End-User, the Authorization Server MUST employ appropriate measures against Cross-Site Request Forgery and Clickjacking as, described in Sections 10.12 and 10.13 of OAuth 2.0.

Once the End-User is authenticated, the Authorization Server MUST obtain an authorization decision before releasing information to the Relying Party. When permitted by the request parameters used, this MAY be done through an interactive dialogue with the End-User that makes it clear what is being consented to or by establishing consent via conditions for processing the request or other means (for example, via previous administrative consent). Sections and describe information release mechanisms.

An Authentication Response is an OAuth 2.0 Authorization Response message returned from the OP's Authorization Endpoint in response to the Authorization Request message sent by the RP. When using the Authorization Code Flow, the Authorization Response MUST return the parameters defined in Section 4.1.2 of OAuth 2.0 by adding them as query parameters to the redirect_uri specified in the Authorization Request using the application/x-www-form-urlencoded format, unless a different Response Mode was specified.

The following is a non-normative example successful response using this flow (with line wraps within values for display purposes only):

For implementation notes on the contents of the Authorization Code, see .

An Authentication Error Response is an OAuth 2.0 Authorization Error Response message returned from the OP's Authorization Endpoint in response to the Authorization Request message sent by the RP. If the End-User denies the request or the End-User authentication fails, the OP (Authorization Server) informs the RP (Client) by using the Error Response parameters defined in Section 4.1.2.1 of OAuth 2.0. (HTTP errors unrelated to RFC 6749 are returned to the User Agent using the appropriate HTTP status code.) Unless the Redirection URI is invalid, the Authorization Server returns the Client to the Redirection URI specified in the Authorization Request with the appropriate error and state parameters. Other parameters SHOULD NOT be returned. If the Redirection URI is invalid, the Authorization Server MUST NOT redirect the User Agent to the invalid Redirection URI. If the Response Mode value is not supported, the Authorization Server returns an HTTP response code of 400 (Bad Request) without Error Response parameters, since understanding the Response Mode is necessary to know how to return those parameters. In addition to the error codes defined in Section 4.1.2.1 of OAuth 2.0, this specification also defines the following error codes: The Authorization Server requires End-User interaction of some form to proceed. This error MAY be returned when the prompt parameter value in the Authentication Request is none, but the Authentication Request cannot be completed without displaying a user interface for End-User interaction. The Authorization Server requires End-User authentication. This error MAY be returned when the prompt parameter value in the Authentication Request is none, but the Authentication Request cannot be completed without displaying a user interface for End-User authentication. The End-User is REQUIRED to select a session at the Authorization Server. The End-User MAY be authenticated at the Authorization Server with different associated accounts, but the End-User did not select a session. This error MAY be returned when the prompt parameter value in the Authentication Request is none, but the Authentication Request cannot be completed without displaying a user interface to prompt for a session to use. The Authorization Server requires End-User consent. This error MAY be returned when the prompt parameter value in the Authentication Request is none, but the Authentication Request cannot be completed without displaying a user interface for End-User consent. The request_uri in the Authorization Request returns an error or contains invalid data. The request parameter contains an invalid Request Object. The OP does not support use of the request parameter defined in . The OP does not support use of the request_uri parameter defined in . The OP does not support use of the registration parameter defined in . The error response parameters are the following: REQUIRED. Error code. OPTIONAL. Human-readable ASCII encoded text description of the error. OPTIONAL. URI of a web page that includes additional information about the error. OAuth 2.0 state value. REQUIRED if the Authorization Request included the state parameter. Set to the value received from the Client. When using the Authorization Code Flow, the error response parameters are added to the query component of the Redirection URI, unless a different Response Mode was specified.

The following is a non-normative example error response using this flow (with line wraps within values for display purposes only):

When using the Authorization Code Flow, the Client MUST validate the response according to RFC 6749, especially Sections 4.1.2 and 10.12.

To obtain an Access Token, an ID Token, and optionally a Refresh Token, the RP (Client) sends a Token Request to the Token Endpoint to obtain a Token Response, as described in Section 3.2 of OAuth 2.0, when using the Authorization Code Flow. Communication with the Token Endpoint MUST utilize TLS. See for more information on using TLS.

A Client makes a Token Request by presenting its Authorization Grant (in the form of an Authorization Code) to the Token Endpoint using the grant_type value authorization_code, as described in Section 4.1.3 of OAuth 2.0. If the Client is a Confidential Client, then it MUST authenticate to the Token Endpoint using the authentication method registered for its client_id, as described in . The Client sends the parameters to the Token Endpoint using the HTTP POST method and the Form Serialization, per , as described in Section 4.1.3 of OAuth 2.0.

The following is a non-normative example of a Token Request (with line wraps within values for display purposes only):

The Authorization Server MUST validate the Token Request as follows: Authenticate the Client if it was issued Client Credentials or if it uses another Client Authentication method, per . Ensure the Authorization Code was issued to the authenticated Client. Verify that the Authorization Code is valid. If possible, verify that the Authorization Code has not been previously used. Ensure that the redirect_uri parameter value is identical to the redirect_uri parameter value that was included in the initial Authorization Request. If the redirect_uri parameter value is not present when there is only one registered redirect_uri value, the Authorization Server MAY return an error (since the Client should have included the parameter) or MAY proceed without an error (since OAuth 2.0 permits the parameter to be omitted in this case). Verify that the Authorization Code used was issued in response to an OpenID Connect Authentication Request (so that an ID Token will be returned from the Token Endpoint).

After receiving and validating a valid and authorized Token Request from the Client, the Authorization Server returns a successful response that includes an ID Token and an Access Token. The parameters in the successful response are defined in Section 4.1.4 of OAuth 2.0. The response uses the application/json media type. The OAuth 2.0 token_type response parameter value MUST be Bearer, as specified in OAuth 2.0 Bearer Token Usage, unless another Token Type has been negotiated with the Client. Servers SHOULD support the Bearer Token Type; use of other Token Types is outside the scope of this specification. Note that the token_type value is case insensitive. In addition to the response parameters specified by OAuth 2.0, the following parameters MUST be included in the response: ID Token value associated with the authenticated session. All Token Responses that contain tokens, secrets, or other sensitive information MUST include the following HTTP response header fields and values: Header Name Header Value Cache-Control no-cache, no-store Pragma no-cache

The following is a non-normative example of a successful Token Response. The ID Token signature in the example can be verified with the key at .

As specified in OAuth 2.0, Clients SHOULD ignore unrecognized response parameters.

If the Token Request is invalid or unauthorized, the Authorization Server constructs the error response. The parameters of the Token Error Response are defined as in Section 5.2 of OAuth 2.0. The HTTP response body uses the application/json media type with HTTP response code of 400.

The following is a non-normative example Token Error Response:

The Client MUST validate the Token Response as follows: Follow the validation rules in RFC 6749, especially those in Sections 5.1 and 10.12. Follow the ID Token validation rules in . Follow the Access Token validation rules in .

The contents of the ID Token are as described in . When using the Authorization Code Flow, these additional requirements for the following ID Token Claims apply: OPTIONAL. Access Token hash value. Its value is the base64url encoding of the left-most half of the hash of the octets of the ASCII representation of the access_token value, where the hash algorithm used is the hash algorithm used in the alg Header Parameter of the ID Token's JOSE Header. For instance, if the alg is RS256, hash the access_token value with SHA-256, then take the left-most 128 bits and base64url-encode them. The at_hash value is a case-sensitive string.

Clients MUST validate the ID Token in the Token Response in the following manner: If the ID Token is encrypted, decrypt it using the keys and algorithms that the Client specified during Registration that the OP was to use to encrypt the ID Token. If encryption was negotiated with the OP at Registration time and the ID Token is not encrypted, the RP SHOULD reject it. The Issuer Identifier for the OpenID Provider (which is typically obtained during Discovery) MUST exactly match the value of the iss (issuer) Claim. The Client MUST validate that the aud (audience) Claim contains its client_id value registered at the Issuer identified by the iss (issuer) Claim as an audience. The aud (audience) Claim MAY contain an array with more than one element. The ID Token MUST be rejected if the ID Token does not list the Client as a valid audience, or if it contains additional audiences not trusted by the Client. If the implementation is using extensions (which are beyond the scope of this specification) that result in the azp (authorized party) Claim being present, it SHOULD validate the azp value as specified by those extensions. This validation MAY include that when an azp (authorized party) Claim is present, the Client SHOULD verify that its client_id is the Claim Value. If the ID Token is received via direct communication between the Client and the Token Endpoint (which it is in this flow), the TLS server validation MAY be used to validate the issuer in place of checking the token signature. The Client MUST validate the signature of all other ID Tokens according to JWS using the algorithm specified in the JWT alg Header Parameter. The Client MUST use the keys provided by the Issuer. The alg value SHOULD be the default of RS256 or the algorithm sent by the Client in the id_token_signed_response_alg parameter during Registration. If the JWT alg Header Parameter uses a MAC based algorithm such as HS256, HS384, or HS512, the octets of the UTF-8 representation of the client_secret corresponding to the client_id contained in the aud (audience) Claim are used as the key to validate the signature. For MAC based algorithms, the behavior is unspecified if the aud is multi-valued. The current time MUST be before the time represented by the exp Claim. The iat Claim can be used to reject tokens that were issued too far away from the current time, limiting the amount of time that nonces need to be stored to prevent attacks. The acceptable range is Client specific. If a nonce value was sent in the Authentication Request, a nonce Claim MUST be present and its value checked to verify that it is the same value as the one that was sent in the Authentication Request. The Client SHOULD check the nonce value for replay attacks. The precise method for detecting replay attacks is Client specific. If the acr Claim was requested, the Client SHOULD check that the asserted Claim Value is appropriate. The meaning and processing of acr Claim Values is out of scope for this specification. If the auth_time Claim was requested, either through a specific request for this Claim or by using the max_age parameter, the Client SHOULD check the auth_time Claim value and request re-authentication if it determines too much time has elapsed since the last End-User authentication.

When using the Authorization Code Flow, if the ID Token contains an at_hash Claim, the Client MAY use it to validate the Access Token in the same manner as for the Implicit Flow, as defined in , but using the ID Token and Access Token returned from the Token Endpoint.

This section describes how to perform authentication using the Implicit Flow. When using the Implicit Flow, all tokens are returned from the Authorization Endpoint; the Token Endpoint is not used. The Implicit Flow is mainly used by Clients implemented in a browser using a scripting language. The Access Token and ID Token are returned directly to the Client, which may expose them to the End-User and applications that have access to the End-User's User Agent. The Authorization Server does not perform Client Authentication.

The Implicit Flow follows the following steps: Client prepares an Authentication Request containing the desired request parameters. Client sends the request to the Authorization Server. Authorization Server Authenticates the End-User. Authorization Server obtains End-User Consent/Authorization. Authorization Server sends the End-User back to the Client with an ID Token and, if requested, an Access Token. Client validates the ID token and retrieves the End-User's Subject Identifier.

When using the Implicit Flow, the Authorization Endpoint is used in the same manner as for the Authorization Code Flow, as defined in , with the exception of the differences specified in this section.

Authentication Requests are made as defined in , except that these Authentication Request parameters are used as follows: REQUIRED. OAuth 2.0 Response Type value that determines the authorization processing flow to be used, including what parameters are returned from the endpoints used. When using the Implicit Flow, this value is id_token token or id_token. The meanings of both of these values are defined in OAuth 2.0 Multiple Response Type Encoding Practices. No Access Token is returned when the value is id_token. NOTE: While OAuth 2.0 also defines the token Response Type value for the Implicit Flow, OpenID Connect does not use this Response Type, since no ID Token would be returned. REQUIRED. Redirection URI to which the response will be sent. This URI MUST exactly match one of the Redirection URI values for the Client pre-registered at the OpenID Provider, with the matching performed as described in Section 6.2.1 of (Simple String Comparison). When using this flow, the Redirection URI MUST NOT use the http scheme unless the Client is a native application, in which case it MAY use the http: scheme with localhost as the hostname. REQUIRED. String value used to associate a Client session with an ID Token, and to mitigate replay attacks. The value is passed through unmodified from the Authentication Request to the ID Token. Sufficient entropy MUST be present in the nonce values used to prevent attackers from guessing values. For implementation notes, see .

The following is a non-normative example request using the Implicit Flow that would be sent by the User Agent to the Authorization Server in response to a corresponding HTTP 302 redirect response by the Client (with line wraps within values for display purposes only):

When using the Implicit Flow, the Authentication Request is validated in the same manner as for the Authorization Code Flow, as defined in .

When using the Implicit Flow, End-User Authentication is performed in the same manner as for the Authorization Code Flow, as defined in .

When using the Implicit Flow, End-User Consent is obtained in the same manner as for the Authorization Code Flow, as defined in .

When using the Implicit Flow, Authentication Responses are made in the same manner as for the Authorization Code Flow, as defined in , with the exception of the differences specified in this section. When using the Implicit Flow, all response parameters are added to the fragment component of the Redirection URI, as specified in OAuth 2.0 Multiple Response Type Encoding Practices, unless a different Response Mode was specified. These parameters are returned from the Authorization Endpoint: OAuth 2.0 Access Token. This is returned unless the response_type value used is id_token. OAuth 2.0 Token Type value. The value MUST be Bearer or another token_type value that the Client has negotiated with the Authorization Server. Clients implementing this profile MUST support the OAuth 2.0 Bearer Token Usage specification. This profile only describes the use of bearer tokens. This is returned in the same cases as access_token is. REQUIRED. ID Token. OAuth 2.0 state value. REQUIRED if the state parameter is present in the Authorization Request. Clients MUST verify that the state value is equal to the value of state parameter in the Authorization Request. OPTIONAL. Expiration time of the Access Token in seconds since the response was generated. Per Section 4.2.2 of OAuth 2.0, no code result is returned when using the Implicit Flow.

The following is a non-normative example of a successful response using the Implicit Flow (with line wraps for the display purposes only):

When using the Implicit Flow, Authorization Error Responses are made in the same manner as for the Authorization Code Flow, as defined in , with the exception of the differences specified in this section. Whenever Error Response parameters are returned, such as when End-User denies the authorization or the End-User authentication fails, the Authorization Server MUST return the error Authorization Response in the fragment component of the Redirection URI, as defined in 4.2.2.1 of OAuth 2.0 and OAuth 2.0 Multiple Response Type Encoding Practices, unless a different Response Mode was specified.

Since response parameters are returned in the Redirection URI fragment value, the Client needs to have the User Agent parse the fragment encoded values and pass them to on to the Client's processing logic for consumption. See for implementation notes on URI fragment handling.

When using the Implicit Flow, the Client MUST validate the response as follows: Verify that the response conforms to Section 5 of . Follow the validation rules in RFC 6749, especially those in Sections 4.2.2 and 10.12. Follow the ID Token validation rules in . Follow the Access Token validation rules in , unless the response_type value used is id_token.

To validate an Access Token issued from the Authorization Endpoint with an ID Token, the Client SHOULD do the following: Hash the octets of the ASCII representation of the access_token with the hash algorithm specified in JWA for the alg Header Parameter of the ID Token's JOSE Header. For instance, if the alg is RS256, the hash algorithm used is SHA-256. Take the left-most half of the hash and base64url-encode it. The value of at_hash in the ID Token MUST match the value produced in the previous step.

The contents of the ID Token are as described in . When using the Implicit Flow, these additional requirements for the following ID Token Claims apply: Use of the nonce Claim is REQUIRED for this flow. Access Token hash value. Its value is the base64url encoding of the left-most half of the hash of the octets of the ASCII representation of the access_token value, where the hash algorithm used is the hash algorithm used in the alg Header Parameter of the ID Token's JOSE Header. For instance, if the alg is RS256, hash the access_token value with SHA-256, then take the left-most 128 bits and base64url-encode them. The at_hash value is a case-sensitive string. If the ID Token is issued from the Authorization Endpoint with an access_token value, which is the case for the response_type value id_token token, this is REQUIRED; it MAY NOT be used when no Access Token is issued, which is the case for the response_type value id_token.

When using the Implicit Flow, the contents of the ID Token MUST be validated in the same manner as for the Authorization Code Flow, as defined in , with the exception of the differences specified in this section. The Client MUST validate the signature of the ID Token according to JWS using the algorithm specified in the alg Header Parameter of the JOSE Header. The value of the nonce Claim MUST be checked to verify that it is the same value as the one that was sent in the Authentication Request. The Client SHOULD check the nonce value for replay attacks. The precise method for detecting replay attacks is Client specific.

This section describes how to perform authentication using the Hybrid Flow. When using the Hybrid Flow, some tokens are returned from the Authorization Endpoint and others are returned from the Token Endpoint. The mechanisms for returning tokens in the Hybrid Flow are specified in OAuth 2.0 Multiple Response Type Encoding Practices.

The Hybrid Flow follows the following steps: Client prepares an Authentication Request containing the desired request parameters. Client sends the request to the Authorization Server. Authorization Server Authenticates the End-User. Authorization Server obtains End-User Consent/Authorization. Authorization Server sends the End-User back to the Client with an Authorization Code and, depending on the Response Type, one or more additional parameters. Client requests a response using the Authorization Code at the Token Endpoint. Client receives a response that contains an ID Token and Access Token in the response body. Client validates the ID Token and retrieves the End-User's Subject Identifier.

When using the Hybrid Flow, the Authorization Endpoint is used in the same manner as for the Authorization Code Flow, as defined in , with the exception of the differences specified in this section.

Authentication Requests are made as defined in , except that these Authentication Request parameters are used as follows: REQUIRED. OAuth 2.0 Response Type value that determines the authorization processing flow to be used, including what parameters are returned from the endpoints used. When using the Hybrid Flow, this value is code id_token, code token, or code id_token token. The meanings of these values are defined in OAuth 2.0 Multiple Response Type Encoding Practices. REQUIRED if the Response Type of the request is code id_token or code id_token token and OPTIONAL when the Response Type of the request is code token. It is a string value used to associate a Client session with an ID Token, and to mitigate replay attacks. The value is passed through unmodified from the Authentication Request to the ID Token. Sufficient entropy MUST be present in the nonce values used to prevent attackers from guessing values. For implementation notes, see .

The following is a non-normative example request using the Hybrid Flow that would be sent by the User Agent to the Authorization Server in response to a corresponding HTTP 302 redirect response by the Client (with line wraps within values for display purposes only):

When using the Hybrid Flow, the Authentication Request is validated in the same manner as for the Authorization Code Flow, as defined in .

When using the Hybrid Flow, End-User Authentication is performed in the same manner as for the Authorization Code Flow, as defined in .

When using the Hybrid Flow, End-User Consent is obtained in the same manner as for the Authorization Code Flow, as defined in .

When using the Hybrid Flow, Authentication Responses are made in the same manner as for the Implicit Flow, as defined in , with the exception of the differences specified in this section. These Authorization Endpoint results are used in the following manner: OAuth 2.0 Access Token. This is returned when the response_type value used is code token, or code id_token token. (A token_type value is also returned in the same cases.) ID Token. This is returned when the response_type value used is code id_token or code id_token token. Authorization Code. This is always returned when using the Hybrid Flow.

The following is a non-normative example of a successful response using the Hybrid Flow (with line wraps for the display purposes only):

When using the Hybrid Flow, Authorization Error Responses are made in the same manner as for the Authorization Code Flow, as defined in , with the exception of the differences specified in this section. Whenever Error Response parameters are returned, such as when End-User denies the authorization or the End-User authentication fails, the Authorization Server MUST return the error Authorization Response in the fragment component of the Redirection URI, as defined in 4.2.2.1 of OAuth 2.0 and OAuth 2.0 Multiple Response Type Encoding Practices, unless a different Response Mode was specified.

When using the Hybrid Flow, the same requirements for Redirection URI fragment parameter handling apply as do for the Implicit Flow, as defined in . Also see for implementation notes on URI fragment handling.

When using the Hybrid Flow, the Client MUST validate the response as follows: Verify that the response conforms to Section 5 of . Follow the validation rules in RFC 6749, especially those in Sections 4.2.2 and 10.12. Follow the ID Token validation rules in when the response_type value used is code id_token or code id_token token. Follow the Access Token validation rules in when the response_type value used is code token or code id_token token. Follow the Authorization Code validation rules in when the response_type value used is code id_token or code id_token token.

When using the Hybrid Flow, Access Tokens returned from the Authorization Endpoint are validated in the same manner as for the Implicit Flow, as defined in .

To validate an Authorization Code issued from the Authorization Endpoint with an ID Token, the Client SHOULD do the following: Hash the octets of the ASCII representation of the code with the hash algorithm specified in JWA for the alg Header Parameter of the ID Token's JOSE Header. For instance, if the alg is RS256, the hash algorithm used is SHA-256. Take the left-most half of the hash and base64url-encode it. The value of c_hash in the ID Token MUST match the value produced in the previous step if c_hash is present in the ID Token.

The contents of the ID Token are as described in . When using the Hybrid Flow, these additional requirements for the following ID Token Claims apply to an ID Token returned from the Authorization Endpoint: If a nonce parameter is present in the Authentication Request, Authorization Servers MUST include a nonce Claim in the ID Token. Access Token hash value. Its value is the base64url encoding of the left-most half of the hash of the octets of the ASCII representation of the access_token value, where the hash algorithm used is the hash algorithm used in the alg Header Parameter of the ID Token's JOSE Header. For instance, if the alg is RS256, hash the access_token value with SHA-256, then take the left-most 128 bits and base64url-encode them. The at_hash value is a case-sensitive string. If the ID Token is issued from the Authorization Endpoint with an access_token value, which is the case for the response_type value code id_token token, this is REQUIRED; otherwise, its inclusion is OPTIONAL. Code hash value. Its value is the base64url encoding of the left-most half of the hash of the octets of the ASCII representation of the code value, where the hash algorithm used is the hash algorithm used in the alg Header Parameter of the ID Token's JOSE Header. For instance, if the alg is HS512, hash the code value with SHA-512, then take the left-most 256 bits and base64url-encode them. The c_hash value is a case-sensitive string. If the ID Token is issued from the Authorization Endpoint with a code, which is the case for the response_type values code id_token and code id_token token, this is REQUIRED; otherwise, its inclusion is OPTIONAL.

When using the Hybrid Flow, the contents of an ID Token returned from the Authorization Endpoint MUST be validated in the same manner as for the Implicit Flow, as defined in .

When using the Hybrid Flow, the Token Endpoint is used in the same manner as for the Authorization Code Flow, as defined in , with the exception of the differences specified in this section.

When using the Hybrid Flow, Token Requests are made in the same manner as for the Authorization Code Flow, as defined in .

When using the Hybrid Flow, Token Requests are validated in the same manner as for the Authorization Code Flow, as defined in .

When using the Hybrid Flow, Token Responses are made in the same manner as for the Authorization Code Flow, as defined in .

When using the Hybrid Flow, Token Error Responses are made in the same manner as for the Authorization Code Flow, as defined in .

When using the Hybrid Flow, Token Responses are validated in the same manner as for the Authorization Code Flow, as defined in .

When using the Hybrid Flow, the contents of an ID Token returned from the Token Endpoint are the same as for an ID Token returned from the Authorization Endpoint, as defined in , with the exception of the differences specified in this section. If an ID Token is returned from both the Authorization Endpoint and from the Token Endpoint, which is the case for the response_type values code id_token and code id_token token, the iss and sub Claim Values MUST be identical in both ID Tokens. All Claims about the Authentication event present in either SHOULD be present in both. If either ID Token contains Claims about the End-User, any that are present in both SHOULD have the same values in both. Note that the OP MAY choose to return fewer Claims about the End-User from the Authorization Endpoint, for instance, for privacy reasons. The at_hash and c_hash Claims MAY be omitted from the ID Token returned from the Token Endpoint even when these Claims are present in the ID Token returned from the Authorization Endpoint, because the ID Token and Access Token values returned from the Token Endpoint are already cryptographically bound together by the TLS encryption performed by the Token Endpoint.

When using the Hybrid Flow, the contents of an ID Token returned from the Token Endpoint MUST be validated in the same manner as for the Authorization Code Flow, as defined in .

If an Access Token is returned from both the Authorization Endpoint and from the Token Endpoint, which is the case for the response_type values code token and code id_token token, their values MAY be the same or they MAY be different. Note that different Access Tokens might be returned be due to the different security characteristics of the two endpoints and the lifetimes and the access to resources granted by them might also be different.

When using the Hybrid Flow, the Access Token returned from the Token Endpoint is validated in the same manner as for the Authorization Code Flow, as defined in .

In some cases, the login flow is initiated by an OpenID Provider or another party, rather than the Relying Party. In this case, the initiator redirects to the RP at its login initiation endpoint, which requests that the RP send an Authentication Request to a specified OP. Note that this login initiation endpoint can be a different page at the RP than the RP's default landing page. RPs supporting OpenID Connect Dynamic Client Registration 1.0 register this endpoint value using the initiate_login_uri Registration parameter. The party initiating the login request does so by redirecting to the login initiation endpoint at the RP, passing the following parameters: REQUIRED. Issuer Identifier for the OP that the RP is to send the Authentication Request to. Its value MUST be a URL using the https scheme. OPTIONAL. Hint to the Authorization Server about the End-User to be authenticated. The meaning of this string-valued parameter is left to the OP's discretion. In common use cases, the value will contain an e-mail address, phone number, or username collected by the RP before requesting authentication at the OP. For example, this hint can be used by an RP after it asks the End-User for their e-mail address (or other identifier), passing that identifier as a hint to the OpenID Provider. It is RECOMMENDED that the hint value match the value provided for discovery. Other uses MAY include using the sub claim from the ID Token as the hint value or potentially other kinds of information about the requested authentication. OPTIONAL. URL that the RP is requested to redirect to after authentication. RPs MUST verify the value of the target_link_uri to prevent being used as an open redirector to external sites. The parameters can either be passed as query parameters using the HTTP GET method or be passed as HTML form values that are auto-submitted in the User Agent, and thus are transmitted via the HTTP POST method. Other parameters MAY be sent, if defined by extensions. Any parameters used that are not understood MUST be ignored by the Client. Clients SHOULD employ frame busting and other techniques to prevent End-Users from being logged in by third party sites without their knowledge through attacks such as Clickjacking. Refer to Section 4.4.1.9 of for more details.

This section specifies how the Client can obtain Claims about the End-User and the Authentication event. It also defines a standard set of basic profile Claims. Pre-defined sets of Claims can be requested using specific scope values or individual Claims can be requested using the claims request parameter. The Claims can come directly from the OpenID Provider or from distributed sources as well.

This specification defines a set of standard Claims. They can be requested to be returned either in the UserInfo Response, per , or in the ID Token, per . Member Type Description sub string Subject - Identifier for the End-User at the Issuer. name string End-User's full name in displayable form including all name parts, possibly including titles and suffixes, ordered according to the End-User's locale and preferences. given_name string Given name(s) or first name(s) of the End-User. Note that in some cultures, people can have multiple given names; all can be present, with the names being separated by space characters. family_name string Surname(s) or last name(s) of the End-User. Note that in some cultures, people can have multiple family names or no family name; all can be present, with the names being separated by space characters. middle_name string Middle name(s) of the End-User. Note that in some cultures, people can have multiple middle names; all can be present, with the names being separated by space characters. Also note that in some cultures, middle names are not used. nickname string Casual name of the End-User that may or may not be the same as the given_name. For instance, a nickname value of Mike might be returned alongside a given_name value of Michael. preferred_username string Shorthand name by which the End-User wishes to be referred to at the RP, such as janedoe or j.doe. This value MAY be any valid JSON string including special characters such as @, /, or whitespace. The RP MUST NOT rely upon this value being unique, as discussed in . profile string URL of the End-User's profile page. The contents of this Web page SHOULD be about the End-User. picture string URL of the End-User's profile picture. This URL MUST refer to an image file (for example, a PNG, JPEG, or GIF image file), rather than to a Web page containing an image. Note that this URL SHOULD specifically reference a profile photo of the End-User suitable for displaying when describing the End-User, rather than an arbitrary photo taken by the End-User. website string URL of the End-User's Web page or blog. This Web page SHOULD contain information published by the End-User or an organization that the End-User is affiliated with. email string End-User's preferred e-mail address. Its value MUST conform to the RFC 5322 addr-spec syntax. The RP MUST NOT rely upon this value being unique, as discussed in . email_verified boolean True if the End-User's e-mail address has been verified; otherwise false. When this Claim Value is true, this means that the OP took affirmative steps to ensure that this e-mail address was controlled by the End-User at the time the verification was performed. The means by which an e-mail address is verified is context specific, and dependent upon the trust framework or contractual agreements within which the parties are operating. gender string End-User's gender. Values defined by this specification are female and male. Other values MAY be used when neither of the defined values are applicable. birthdate string End-User's birthday, represented as an ISO 8601:2004 YYYY-MM-DD format. The year MAY be 0000, indicating that it is omitted. To represent only the year, YYYY format is allowed. Note that depending on the underlying platform's date related function, providing just year can result in varying month and day, so the implementers need to take this factor into account to correctly process the dates. zoneinfo string String from IANA Time Zone Database representing the End-User's time zone. For example, Europe/Paris or America/Los_Angeles. locale string End-User's locale, represented as a BCP47 language tag. This is typically an ISO 639-1 Alpha-2 language code in lowercase and an ISO 3166-1 Alpha-2 country code in uppercase, separated by a dash. For example, en-US or fr-CA. As a compatibility note, some implementations have used an underscore as the separator rather than a dash, for example, en_US; Relying Parties MAY choose to accept this locale syntax as well. phone_number string End-User's preferred telephone number. E.164 is RECOMMENDED as the format of this Claim, for example, +1 (425) 555-1212 or +56 (2) 687 2400. If the phone number contains an extension, it is RECOMMENDED that the extension be represented using the RFC 3966 extension syntax, for example, +1 (604) 555-1234;ext=5678. phone_number_verified boolean True if the End-User's phone number has been verified; otherwise false. When this Claim Value is true, this means that the OP took affirmative steps to ensure that this phone number was controlled by the End-User at the time the verification was performed. The means by which a phone number is verified is context specific, and dependent upon the trust framework or contractual agreements within which the parties are operating. When true, the phone_number Claim MUST be in E.164 format and any extensions MUST be represented in RFC 3966 format. address JSON object End-User's preferred postal address. The value of the address member is a JSON structure containing some or all of the members defined in . updated_at number Time the End-User's information was last updated. Its value is a JSON number representing the number of seconds from 1970-01-01T00:00:00Z as measured in UTC until the date/time.

The Address Claim represents a physical mailing address. Implementations MAY return only a subset of the fields of an address, depending upon the information available and the End-User's privacy preferences. For example, the country and region might be returned without returning more fine-grained address information. Implementations MAY return just the full address as a single string in the formatted sub-field, or they MAY return just the individual component fields using the other sub-fields, or they MAY return both. If both variants are returned, they SHOULD be describing the same address, with the formatted address indicating how the component fields are combined. Full mailing address, formatted for display or use on a mailing label. This field MAY contain multiple lines, separated by newlines. Newlines can be represented either as a carriage return/line feed pair ("\r\n") or as a single line feed character ("\n"). Full street address component, which MAY include house number, street name, Post Office Box, and multi-line extended street address information. This field MAY contain multiple lines, separated by newlines. Newlines can be represented either as a carriage return/line feed pair ("\r\n") or as a single line feed character ("\n"). City or locality component. State, province, prefecture, or region component. Zip code or postal code component. Country name component.

While this specification defines only a small set of Claims as standard Claims, other Claims MAY be used in conjunction with the standard Claims. When using such Claims, it is RECOMMENDED that collision-resistant names be used for the Claim Names, as described in the JSON Web Token (JWT) specification. Alternatively, Private Claim Names can be safely used when naming conflicts are unlikely to arise, as described in the JWT specification. Or, if specific additional Claims will have broad and general applicability, they can be registered with Registered Claim Names, per the JWT specification.

Human-readable Claim Values and Claim Values that reference human-readable values MAY be represented in multiple languages and scripts. To specify the languages and scripts, BCP47 language tags are added to member names, delimited by a # character. For example, family_name#ja-Kana-JP expresses the Family Name in Katakana in Japanese, which is commonly used to index and represent the phonetics of the Kanji representation of the same represented as family_name#ja-Hani-JP. As another example, both website and website#de Claim Values might be returned, referencing a Web site in an unspecified language and a Web site in German. Since Claim Names are case sensitive, it is strongly RECOMMENDED that language tag values used in Claim Names be spelled using the character case with which they are registered in the IANA "Language Subtag Registry" . In particular, normally language names are spelled with lowercase characters, region names are spelled with uppercase characters, and scripts are spelled with mixed case characters. However, since BCP47 language tag values are case insensitive, implementations SHOULD interpret the language tag values supplied in a case-insensitive manner. Per the recommendations in BCP47, language tag values for Claims SHOULD only be as specific as necessary. For instance, using fr might be sufficient in many contexts, rather than fr-CA or fr-FR. Where possible, OPs SHOULD try to match requested Claim locales with Claims it has. For instance, if the Client asks for a Claim with a de (German) language tag and the OP has a value tagged with de-CH (Swiss German) and no generic German value, it would be appropriate for the OP to return the Swiss German value to the Client. (This intentionally moves as much of the complexity of language tag matching to the OP as possible, to simplify Clients.) OpenID Connect defines the following Authorization Request parameter to enable specify the preferred languages and scripts to be used for the returned Claims: OPTIONAL. End-User's preferred languages and scripts for Claims being returned, represented as a space-separated list of BCP47 language tag values, ordered by preference. An error SHOULD NOT result if some or all of the requested locales are not supported by the OpenID Provider. When the OP determines, either through the claims_locales parameter, or by other means, that the End-User and Client are requesting Claims in only one set of languages and scripts, it is RECOMMENDED that OPs return Claims without language tags when they employ this language and script. It is also RECOMMENDED that Clients be written in a manner that they can handle and utilize Claims using language tags.

The UserInfo Endpoint is an OAuth 2.0 Protected Resource that returns Claims about the authenticated End-User. To obtain the requested Claims about the End-User, the Client makes a request to the UserInfo Endpoint using an Access Token obtained through OpenID Connect Authentication. These Claims are normally represented by a JSON object that contains a collection of name and value pairs for the Claims. Communication with the UserInfo Endpoint MUST utilize TLS. See for more information on using TLS. The UserInfo Endpoint MUST support the use of the HTTP GET and HTTP POST methods defined in RFC 7231. The UserInfo Endpoint MUST accept Access Tokens as OAuth 2.0 Bearer Token Usage. The UserInfo Endpoint SHOULD support the use of Cross-Origin Resource Sharing (CORS) and/or other methods as appropriate to enable Java Script Clients to access it.

The Client sends the UserInfo Request using either HTTP GET or HTTP POST. The Access Token obtained from an OpenID Connect Authentication Request MUST be sent as a Bearer Token, per Section 2 of OAuth 2.0 Bearer Token Usage. It is RECOMMENDED that the request use the HTTP GET method and the Access Token be sent using the Authorization header field.

The following is a non-normative example of a UserInfo Request:

The UserInfo Claims MUST be returned as the members of a JSON object unless a signed or encrypted response was requested during Client Registration. The Claims defined in can be returned, as can additional Claims not specified there. For privacy reasons, OpenID Providers MAY elect to not return values for some requested Claims. It is not an error condition to not return a requested Claim. If a Claim is not returned, that Claim Name SHOULD be omitted from the JSON object representing the Claims; it SHOULD NOT be present with a null or empty string value. The sub (subject) Claim MUST always be returned in the UserInfo Response. NOTE: Due to the possibility of token substitution attacks (see ), the UserInfo Response is not guaranteed to be about the End-User identified by the sub (subject) element of the ID Token. The sub Claim in the UserInfo Response MUST be verified to exactly match the sub Claim in the ID Token; if they do not match, the UserInfo Response values MUST NOT be used. Upon receipt of the UserInfo Request, the UserInfo Endpoint MUST return the JSON Serialization of the UserInfo Response as in in the HTTP response body unless a different format was specified during Registration . The UserInfo Endpoint MUST return a content-type header to indicate which format is being returned. The content-type of the HTTP response MUST be application/json if the response body is a text JSON object; the response body SHOULD be encoded using UTF-8. If the UserInfo Response is signed and/or encrypted, then the Claims are returned in a JWT and the content-type MUST be application/jwt. The response MAY be encrypted without also being signed. If both signing and encryption are requested, the response MUST be signed then encrypted, with the result being a Nested JWT, as defined in . If signed, the UserInfo Response MUST contain the Claims iss (issuer) and aud (audience) as members. The iss value MUST be the OP's Issuer Identifier URL. The aud value MUST be or include the RP's Client ID value.

The following is a non-normative example of a UserInfo Response:

When an error condition occurs, the UserInfo Endpoint returns an Error Response as defined in Section 3 of OAuth 2.0 Bearer Token Usage. (HTTP errors unrelated to RFC 6750 are returned to the User Agent using the appropriate HTTP status code.)

The following is a non-normative example of a UserInfo Error Response:

The Client MUST validate the UserInfo Response as follows: Verify that the OP that responded was the intended OP through a TLS server certificate check, per RFC 6125. If the Client has provided a userinfo_encrypted_response_alg parameter during Registration, decrypt the UserInfo Response using the keys specified during Registration. If the response was signed, the Client SHOULD validate the signature according to JWS.

OpenID Connect Clients use scope values, as defined in Section 3.3 of OAuth 2.0, to specify what access privileges are being requested for Access Tokens. The scopes associated with Access Tokens determine what resources will be available when they are used to access OAuth 2.0 protected endpoints. Protected Resource endpoints MAY perform different actions and return different information based on the scope values and other parameters used when requesting the presented Access Token. For OpenID Connect, scopes can be used to request that specific sets of information be made available as Claim Values. Claims requested by the following scopes are treated by Authorization Servers as Voluntary Claims. OpenID Connect defines the following scope values that are used to request Claims: OPTIONAL. This scope value requests access to the End-User's default profile Claims, which are: name, family_name, given_name, middle_name, nickname, preferred_username, profile, picture, website, gender, birthdate, zoneinfo, locale, and updated_at. OPTIONAL. This scope value requests access to the email and email_verified Claims. OPTIONAL. This scope value requests access to the address Claim. OPTIONAL. This scope value requests access to the phone_number and phone_number_verified Claims. Multiple scope values MAY be used by creating a space-delimited, case-sensitive list of ASCII scope values. The Claims requested by the profile, email, address, and phone scope values are returned from the UserInfo Endpoint, as described in , when a response_type value is used that results in an Access Token being issued. However, when no Access Token is issued (which is the case for the response_type value id_token), the resulting Claims are returned in the ID Token. In some cases, the End-User will be given the option to have the OpenID Provider decline to provide some or all information requested by RPs. To minimize the amount of information that the End-User is being asked to disclose, an RP can elect to only request a subset of the information available from the UserInfo Endpoint.

The following is a non-normative example of an unencoded scope request:

OpenID Connect defines the following Authorization Request parameter to enable requesting individual Claims and specifying parameters that apply to the requested Claims: OPTIONAL. This parameter is used to request that specific Claims be returned. The value is a JSON object listing the requested Claims. The claims Authentication Request parameter requests that specific Claims be returned from the UserInfo Endpoint and/or in the ID Token. It is represented as a JSON object containing lists of Claims being requested from these locations. Properties of the Claims being requested MAY also be specified. Support for the claims parameter is OPTIONAL. Should an OP not support this parameter and an RP uses it, the OP SHOULD return a set of Claims to the RP that it believes would be useful to the RP and the End-User using whatever heuristics it believes are appropriate. The claims_parameter_supported Discovery result indicates whether the OP supports this parameter. The claims parameter value is represented in an OAuth 2.0 request as UTF-8 encoded JSON (which ends up being form-urlencoded when passed as an OAuth parameter). When used in a Request Object value, per , the JSON is used as the value of the claims member. The top-level members of the Claims request JSON object are: OPTIONAL. Requests that the listed individual Claims be returned from the UserInfo Endpoint. If present, the listed Claims are being requested to be added to any Claims that are being requested using scope values. If not present, the Claims being requested from the UserInfo Endpoint are only those requested using scope values. When the userinfo member is used, the request MUST also use a response_type value that results in an Access Token being issued to the Client for use at the UserInfo Endpoint. OPTIONAL. Requests that the listed individual Claims be returned in the ID Token. If present, the listed Claims are being requested to be added to the default Claims in the ID Token. If not present, the default ID Token Claims are requested, as per the ID Token definition in and per the additional per-flow ID Token requirements in Sections , , , and . Other members MAY be present. Any members used that are not understood MUST be ignored.

An example Claims request is as follows:

Note that a Claim that is not in the standard set defined in , the (example) http://example.info/claims/groups Claim, is being requested. Using the claims parameter is the only way to request specific combinations of Claims that cannot be specified using scope values.

The userinfo and id_token members of the claims request both are JSON objects with the names of the individual Claims being requested as the member names. The member values MUST be one of the following: Indicates that this Claim is being requested in the default manner. In particular, this is a Voluntary Claim. For instance, the Claim request:

requests the given_name Claim in the default manner. Used to provide additional information about the Claim being requested. This specification defines the following members: OPTIONAL. Indicates whether the Claim being requested is an Essential Claim. If the value is true, this indicates that the Claim is an Essential Claim. For instance, the Claim request:

can be used to specify that it is Essential to return an auth_time Claim Value. If the value is false, it indicates that it is a Voluntary Claim. The default is false. By requesting Claims as Essential Claims, the RP indicates to the End-User that releasing these Claims will ensure a smooth authorization for the specific task requested by the End-User. Note that even if the Claims are not available because the End-User did not authorize their release or they are not present, the Authorization Server MUST NOT generate an error when Claims are not returned, whether they are Essential or Voluntary, unless otherwise specified in the description of the specific claim. OPTIONAL. Requests that the Claim be returned with a particular value. For instance, the Claim request:

can be used to specify that the request apply to the End-User with Subject Identifier 248289761001. The value of the value member MUST be a valid value for the Claim being requested. Definitions of individual Claims can include requirements on how and whether the value qualifier is to be used when requesting that Claim. An equality comparison is used to determine whether the requested Claim value matches. When the Claim value does not match the requested value, the Claim is not included in the response. If the Claim was sub, a mismatch MUST cause the authentication to fail, as described in . OPTIONAL. Requests that the Claim be returned with one of a set of values, with the values appearing in order of preference. This is processed equivalently to a value request, except that a choice of acceptable Claim values is provided. For instance, the Claim request:

specifies that it is Essential that the acr Claim be returned with either the value urn:mace:incommon:iap:silver or urn:mace:incommon:iap:bronze. The values in the values member array MUST be valid values for the Claim being requested. Definitions of individual Claims can include requirements on how and whether the values qualifier is to be used when requesting that Claim. An equality comparison is used to determine whether the requested Claim values match. When the Claim value does not match any of the requested values, the Claim is not included in the response. Other members MAY be defined to provide additional information about the requested Claims. Any members used that are not understood MUST be ignored. Note that when the claims request parameter is supported, the scope values that request Claims, as defined in , are effectively shorthand methods for requesting sets of individual Claims. For example, using the scope value openid email and a response_type that returns an Access Token is equivalent to using the scope value openid and the following request for individual Claims.

Equivalent of using the email scope value:

If the acr Claim is requested as an Essential Claim for the ID Token with a value or values parameter requesting specific Authentication Context Class Reference values and the implementation supports the claims parameter, the Authorization Server MUST return an acr Claim Value that matches one of the requested values. The Authorization Server MAY ask the End-User to re-authenticate with additional factors to meet this requirement. If this is an Essential Claim and the requirement cannot be met, then the Authorization Server MUST treat that outcome as a failed authentication attempt. Note that the RP MAY request the acr Claim as a Voluntary Claim by using the acr_values request parameter or by not including "essential": true in an individual acr Claim request. If the Claim is not Essential and a requested value cannot be provided, the Authorization Server SHOULD return the session's current acr as the value of the acr Claim. If the Claim is not Essential, the Authorization Server is not required to provide this Claim in its response. If the client requests the acr Claim using both the acr_values request parameter and an individual acr Claim request for the ID Token listing specific requested values, the resulting behavior is unspecified.

As described in , human-readable Claim Values and Claim Values that reference human-readable values MAY be represented in multiple languages and scripts. Within a request for individual Claims, requested languages and scripts for particular Claims MAY be requested by including Claim Names that contain #-separated BCP47 language tags in the Claims request, using the Claim Name syntax specified in . For example, a Family Name in Katakana in Japanese can be requested using the Claim Name family_name#ja-Kana-JP and a Kanji representation of the Family Name in Japanese can be requested using the Claim Name family_name#ja-Hani-JP. A German-language Web site can be requested with the Claim Name website#de. If an OP receives a request for human-readable Claims in a language and script that it does not have, any versions of those Claims returned that do not use the requested language and script SHOULD use a language tag in the Claim Name.

Three representations of Claim Values are defined by this specification: Claims that are directly asserted by the OpenID Provider. Claims that are asserted by a Claims Provider other than the OpenID Provider but are returned by OpenID Provider. Claims that are asserted by a Claims Provider other than the OpenID Provider but are returned as references by the OpenID Provider. Normal Claims MUST be supported. Support for Aggregated Claims and Distributed Claims is OPTIONAL.

Normal Claims are represented as members in a JSON object. The Claim Name is the member name and the Claim Value is the member value. The following is a non-normative response containing Normal Claims:

Aggregated and distributed Claims are represented by using special _claim_names and _claim_sources members of the JSON object containing the Claims. JSON object whose member names are the Claim Names for the Aggregated and Distributed Claims. The member values are references to the member names in the _claim_sources member from which the actual Claim Values can be retrieved. The OP MAY omit some Claims available from referenced Claims Providers from the set of Claim Names. JSON object whose member names are referenced by the member values of the _claim_names member. The member values contain sets of Aggregated Claims or reference locations for Distributed Claims. The member values can have one of the following formats depending on whether it is providing Aggregated or Distributed Claims: JSON object that MUST contain the JWT member whose value is a JWT that MUST contain all the Claims in the _claim_names object that references the corresponding _claim_sources member. Other members MAY be present. Any members used that are not understood MUST be ignored. REQUIRED. JWT containing Claim Values. The JWT SHOULD NOT contain a sub (subject) Claim unless its value is an identifier for the End-User at the Claims Provider (and not for the OpenID Provider or another party); this typically means that a sub Claim SHOULD NOT be provided. JSON object that contains the following members and values: REQUIRED. OAuth 2.0 resource endpoint from which the associated Claim can be retrieved. The endpoint URL MUST return the Claim as a JWT. OPTIONAL. Access Token enabling retrieval of the Claims from the endpoint URL by using the OAuth 2.0 Bearer Token Usage protocol. Claims SHOULD be requested using the Authorization Request header field and Claims Providers MUST support this method. If the Access Token is not available, RPs MAY need to retrieve the Access Token out of band or use an Access Token that was pre-negotiated between the Claims Provider and RP, or the Claims Provider MAY reauthenticate the End-User and/or reauthorize the RP. Since it is not an error condition to not return a requested Claim, RPs MUST be prepared to handle the condition that some Claims listed in _claim_sources are not returned from the Claims Provider. They SHOULD treat this the same as when any other requested Claim is not returned. A sub (subject) Claim SHOULD NOT be returned from the Claims Provider unless its value is an identifier for the End-User at the Claims Provider (and not for the OpenID Provider or another party); this typically means that a sub Claim SHOULD NOT be provided. An iss (issuer) Claim SHOULD be included in any JWT issued by a Claims Provider so that the Claims Provider's keys can be retrieved for signature validation of the JWT. The value of the Claim is the Claims Provider's Issuer Identifier URL. In general, it is up to the OP when it is appropriate to use Aggregated Claims and Distributed Claims. In some cases, information about when to use what Claim Types might be negotiated out of band between RPs and OPs.

In this non-normative example, Claims from Claims Provider A are combined with other Claims held by the OpenID provider, with the Claims from Claims Provider A being returned as Aggregated Claims.

In this example, these Claims about Jane Doe have been issued by Claims Provider A. (The example also includes the Claims Provider's Issuer Identifier URL.)

Claims Provider A signs the JSON Claims, representing them in a signed JWT: jwt_header.jwt_part2.jwt_part3. It is this JWT that is used by the OpenID Provider.

In this example, this JWT containing Jane Doe's Aggregated Claims from Claims Provider A is combined with other Normal Claims, and returned as the following set of Claims:

In this non-normative example, the OpenID Provider combines Normal Claims that it holds with references to Claims held by two different Claims Providers, B and C, incorporating references to some of the Claims held by B and C as Distributed Claims.

In this example, these Claims about Jane Doe are held by Claims Provider B (Jane Doe's bank). (The example also includes the Claims Provider's Issuer Identifier URL.)

Also in this example, this Claim about Jane Doe is held by Claims Provider C (a credit agency). (The example also includes the Claims Provider's Issuer Identifier URL.)

The OpenID Provider returns Jane Doe's Claims along with references to the Distributed Claims from Claims Provider B and Claims Provider C by sending the Access Tokens and URLs of locations from which the Distributed Claims can be retrieved:

Note that not returning phone_number, which is held by Claims Provider B, demonstrates that not all Claims held by a utilized Claims Provider need be included.

The sub (subject) and iss (issuer) Claims from the ID Token, used together, are the only Claims that an RP can rely upon as a stable identifier for the End-User, since the sub Claim MUST be locally unique and never reassigned within the Issuer for a particular End-User, as described in . Therefore, the only guaranteed unique identifier for a given End-User is the combination of the iss Claim and the sub Claim. All other Claims carry no such guarantees across different issuers in terms of stability over time or uniqueness across users, and Issuers are permitted to apply local restrictions and policies. For instance, an Issuer MAY re-use an email Claim Value across different End-Users at different points in time, and the claimed email address for a given End-User MAY change over time. Therefore, other Claims such as email, phone_number, preferred_username, and name MUST NOT be used as unique identifiers for the End-User, whether obtained from the ID Token or the UserInfo Endpoint.

OpenID Connect defines the following Authorization Request parameters to enable Authentication Requests to be signed and optionally encrypted: OPTIONAL. This parameter enables OpenID Connect requests to be passed in a single, self-contained parameter and to be optionally signed and/or encrypted. The parameter value is a Request Object value, as specified in . It represents the request as a JWT whose Claims are the request parameters. OPTIONAL. This parameter enables OpenID Connect requests to be passed by reference, rather than by value. The request_uri value is a URL referencing a resource containing a Request Object value, which is a JWT containing the request parameters. This URL MUST use the https scheme unless the target Request Object is signed in a way that is verifiable by the OP. Requests using these parameters are represented as JWTs, which are respectively passed by value or by reference. The ability to pass requests by reference is particularly useful for large requests. If one of these parameters is used, the other MUST NOT be used in the same request.

The request Authorization Request parameter enables OpenID Connect requests to be passed in a single, self-contained parameter and to be optionally signed and/or encrypted. It represents the request as a JWT whose Claims are the request parameters specified in . This JWT is called a Request Object. Support for the request parameter is OPTIONAL. The request_parameter_supported Discovery result indicates whether the OP supports this parameter. Should an OP not support this parameter and an RP uses it, the OP MUST return the request_not_supported error. When the request parameter is used, the OpenID Connect request parameter values contained in the JWT supersede those passed using the OAuth 2.0 request syntax. However, parameters MAY also be passed using the OAuth 2.0 request syntax even when a Request Object is used; this would typically be done to enable a cached, pre-signed (and possibly pre-encrypted) Request Object value to be used containing the fixed request parameters, while parameters that can vary with each request, such as state and nonce, are passed as OAuth 2.0 parameters. So that the request is a valid OAuth 2.0 Authorization Request, values for the response_type and client_id parameters MUST be included using the OAuth 2.0 request syntax, since they are REQUIRED by OAuth 2.0. The values for these parameters MUST match those in the Request Object, if present. Even if a scope parameter is present in the Request Object value, a scope parameter MUST always be passed using the OAuth 2.0 request syntax containing the openid scope value to indicate to the underlying OAuth 2.0 logic that this is an OpenID Connect request. The Request Object MAY be signed or unsigned (unsecured). When it is unsecured, this is indicated by use of the none algorithm in the JOSE Header. If signed, the Request Object SHOULD contain the Claims iss (issuer) and aud (audience) as members. The iss value SHOULD be the Client ID of the RP, unless it was signed by a different party than the RP. The aud value SHOULD be or include the OP's Issuer Identifier URL. The Request Object MAY also be encrypted using JWE and MAY be encrypted without also being signed. If both signing and encryption are performed, it MUST be signed then encrypted, with the result being a Nested JWT, as defined in . request and request_uri parameters MUST NOT be included in Request Objects.

The following is a non-normative example of the Claims in a Request Object before base64url-encoding and signing:

Signing it with the RS256 algorithm results in this Request Object value (with line wraps within values for display purposes only):

The following RSA public key, represented in JWK format, can be used to validate the Request Object signature in this and subsequent Request Object examples (with line wraps within values for display purposes only):

The Client sends the Authorization Request to the Authorization Endpoint.

The following is a non-normative example of an Authorization Request using the request parameter (with line wraps within values for display purposes only):

The request_uri Authorization Request parameter enables OpenID Connect requests to be passed by reference, rather than by value. This parameter is used identically to the request parameter, other than that the Request Object value is retrieved from the resource at the specified URL, rather than passed by value. The request_uri_parameter_supported Discovery result indicates whether the OP supports this parameter. Should an OP not support this parameter and an RP uses it, the OP MUST return the request_uri_not_supported error. When the request_uri parameter is used, the OpenID Connect request parameter values contained in the referenced JWT supersede those passed using the OAuth 2.0 request syntax. However, parameters MAY also be passed using the OAuth 2.0 request syntax even when a request_uri is used; this would typically be done to enable a cached, pre-signed (and possibly pre-encrypted) Request Object value to be used containing the fixed request parameters, while parameters that can vary with each request, such as state and nonce, are passed as OAuth 2.0 parameters. So that the request is a valid OAuth 2.0 Authorization Request, values for the response_type and client_id parameters MUST be included using the OAuth 2.0 request syntax, since they are REQUIRED by OAuth 2.0. The values for these parameters MUST match those in the Request Object, if present. Even if a scope parameter is present in the referenced Request Object, a scope parameter MUST always be passed using the OAuth 2.0 request syntax containing the openid scope value to indicate to the underlying OAuth 2.0 logic that this is an OpenID Connect request. Servers MAY cache the contents of the resources referenced by Request URIs. If the contents of the referenced resource could ever change, the URI SHOULD include the base64url-encoded SHA-256 hash of the referenced resource contents as the fragment component of the URI. If the fragment value used for a URI changes, that signals the server that any cached value for that URI with the old fragment value is no longer valid. Note that Clients MAY pre-register request_uri values using the request_uris parameter defined in Section 2.1 of the OpenID Connect Dynamic Client Registration 1.0 specification. OPs can require that request_uri values used be pre-registered with the require_request_uri_registration discovery parameter. The entire Request URI SHOULD NOT exceed 512 ASCII characters. The contents of the resource referenced by the URL MUST be a Request Object. The scheme used in the request_uri value MUST be https, unless the target Request Object is signed in a way that is verifiable by the Authorization Server. The request_uri value MUST be reachable by the Authorization Server and SHOULD be reachable by the Client.

The following is a non-normative example of the contents of a Request Object resource that can be referenced by a request_uri (with line wraps within values for display purposes only):

The Client stores the Request Object resource either locally or remotely at a URL the Server can access. This URL is the Request URI, request_uri. If the Request Object includes requested values for Claims, it MUST NOT be revealed to anybody but the Authorization Server. As such, the request_uri MUST have appropriate entropy for its lifetime. It is RECOMMENDED that it be removed if it is known that it will not be used again or after a reasonable timeout unless access control measures are taken.

The following is a non-normative example of a Request URI value (with line wraps within values for display purposes only):

The Client sends the Authorization Request to the Authorization Endpoint.

The following is a non-normative example of an Authorization Request using the request_uri parameter (with line wraps within values for display purposes only):

Upon receipt of the Request, the Authorization Server MUST send an HTTP GET request to the request_uri to retrieve the referenced Request Object, unless it is already cached, and parse it to recreate the Authorization Request parameters. Note that the RP SHOULD use a unique URI for each request utilizing distinct parameters, or otherwise prevent the Authorization Server from caching the request_uri.

The following is a non-normative example of this fetch process:

There are several reasons that one might choose to use the request_uri parameter: The set of request parameters can become large and can exceed browser URI size limitations. Passing the request parameters by reference can solve this problem. Passing a request_uri value, rather than a complete request by value, can reduce request latency. Most requests for Claims from an RP are constant. The request_uri is a way of creating and sometimes also signing and encrypting a constant set of request parameters in advance. (The request_uri value becomes an "artifact" representing a particular fixed set of request parameters.) Pre-registering a fixed set of request parameters at Registration time enables OPs to cache and pre-validate the request parameters at Registration time, meaning they need not be retrieved at request time. Pre-registering a fixed set of request parameters at Registration time enables OPs to vet the contents of the request from consumer protection and other points of views, either itself or by utilizing a third party.

When the request or request_uri Authorization Request parameters are used, additional steps must be performed to validate the Authentication Request beyond those specified in Sections , , or . These steps are to validate the JWT containing the Request Object and to validate the Request Object itself.

If the Authorization Server has advertised JWE encryption algorithms in the request_object_encryption_alg_values_supported and request_object_encryption_enc_values_supported elements of its Discovery document , or has supplied encryption algorithms by other means, these are used by the Client to encrypt the JWT. The Authorization Server MUST decrypt the JWT in accordance with the JSON Web Encryption specification. The result MAY be either a signed or unsigned (unsecured) Request Object. In the former case, signature validation MUST be performed as defined in . The Authorization Server MUST return an error if decryption fails.

To perform Signature Validation, the alg Header Parameter in the JOSE Header MUST match the value of the request_object_signing_alg set during Client Registration or a value that was pre-registered by other means. The signature MUST be validated against the appropriate key for that client_id and algorithm. The Authorization Server MUST return an error if signature validation fails.

The Authorization Server MUST assemble the set of Authorization Request parameters to be used from the Request Object value and the OAuth 2.0 Authorization Request parameters (minus the request or request_uri parameters). If the same parameter exists both in the Request Object and the OAuth Authorization Request parameters, the parameter in the Request Object is used. Using the assembled set of Authorization Request parameters, the Authorization Server then validates the request the normal manner for the flow being used, as specified in Sections , , or .

OpenID Connect supports Self-Issued OpenID Providers - personal, self-hosted OPs that issue self-signed ID Tokens. Self-Issued OPs use the special Issuer Identifier https://self-issued.me. The messages used to communicate with Self-Issued OPs are mostly the same as those used to communicate with other OPs. Specifications for the few additional parameters used and for the values of some parameters in the Self-Issued case are defined in this section.

If the input identifier for the discovery process contains the domain self-issued.me, dynamic discovery is not performed. Instead, then the following static configuration values are used:

NOTE: The OpenID Foundation plans to host the OpenID Provider site https://self-issued.me/, including its WebFinger service, so that performing discovery on it returns the above static discovery information, enabling RPs to not need any special processing for discovery of the Self-Issued OP. This site will be hosted on an experimental basis. Production implementations should not take a dependency upon it without a subsequent commitment by the OpenID Foundation to host the site in a manner intended for production use.

When using a Self-Issued OP, registration is not required. The Client can proceed without registration as if it had registered with the OP and obtained the following Client Registration Response: redirect_uri value of the Client. 0 NOTE: The OpenID Foundation plans to host the (stateless) endpoint https://self-issued.me/registration/1.0/ that returns the response above, enabling RPs to not need any special processing for registration with the Self-Issued OP. This site will be hosted on an experimental basis. Production implementations should not take a dependency upon it without a subsequent commitment by the OpenID Foundation to host the site in a manner intended for production use.

OpenID Connect defines the following Authorization Request parameter to enable Clients to provide additional registration information to Self-Issued OpenID Providers: OPTIONAL. This parameter is used by the Client to provide information about itself to a Self-Issued OP that would normally be provided to an OP during Dynamic Client Registration. The value is a JSON object containing Client metadata values, as defined in Section 2.1 of the OpenID Connect Dynamic Client Registration 1.0 specification. The registration parameter SHOULD NOT be used when the OP is not a Self-Issued OP. None of this information is REQUIRED by Self-Issued OPs, so the use of this parameter is OPTIONAL. The registration parameter value is represented in an OAuth 2.0 request as a UTF-8 encoded JSON object (which ends up being form-urlencoded when passed as an OAuth parameter). When used in a Request Object value, per , the JSON object is used as the value of the registration member. The Registration parameters that would typically be used in requests to Self-Issued OPs are policy_uri, tos_uri, and logo_uri. If the Client uses more than one Redirection URI, the redirect_uris parameter would be used to register them. Finally, if the Client is requesting encrypted responses, it would typically use the jwks_uri, id_token_encrypted_response_alg and id_token_encrypted_response_enc parameters.

The self-issued OP's Authorization Endpoint is the URI openid:. The Client sends the Authentication Request to the Authorization Endpoint with the following parameters: REQUIRED. scope parameter value, as specified in . REQUIRED. Constant string value id_token. REQUIRED. Client ID value for the Client, which in this case contains the redirect_uri value of the Client. Since the Client's redirect_uri URI value is communicated as the Client ID, a redirect_uri parameter is NOT REQUIRED to also be included in the request. OPTIONAL. id_token_hint parameter value, as specified in . Encrypting content to Self-Issued OPs is not supported. OPTIONAL. claims parameter value, as specified in . OPTIONAL. This parameter is used by the Client to provide information about itself to a Self-Issued OP that would normally be provided to an OP during Dynamic Client Registration, as specified in . OPTIONAL. Request Object value, as specified in . Encrypting content to Self-Issued OPs is not supported. Other parameters MAY be sent. Note that all Claims are returned in the ID Token. The entire URL MUST NOT exceed 2048 ASCII characters.

The following is a non-normative example HTTP 302 redirect response by the Client, which triggers the User Agent to make an Authentication Request to the Self-Issued OpenID Provider (with line wraps within values for display purposes only):

OpenID Connect defines the following Claim for use in Self-Issued OpenID Provider Responses: REQUIRED. Public key used to check the signature of an ID Token issued by a Self-Issued OpenID Provider, as specified in . The key is a bare key in JWK format (not an X.509 certificate value). The sub_jwk value is a JSON object. Use of the sub_jwk Claim is NOT RECOMMENDED when the OP is not Self-Issued. The Self-Issued OpenID Provider response is the same as the normal Implicit Flow response with the following refinements. Since it is an Implicit Flow response, the response parameters will be returned in the URL fragment component, unless a different Response Mode was specified. The iss (issuer) Claim Value is https://self-issued.me. A sub_jwk Claim is present, with its value being the public key used to check the signature of the ID Token. The sub (subject) Claim value is the base64url-encoded representation of the thumbprint of the key in the sub_jwk Claim. This thumbprint value is computed as the SHA-256 hash of the octets of the UTF-8 representation of a JWK constructed containing only the REQUIRED members to represent the key, with the member names sorted into lexicographic order, and with no whitespace or line breaks. For instance, when the kty value is RSA, the member names e, kty, and n are the ones present in the constructed JWK used in the thumbprint computation and appear in that order; when the kty value is EC, the member names crv, kty, x, and y are present in that order. Note that this thumbprint calculation is the same as that defined in the JWK Thumbprint specification. No Access Token is returned for accessing a UserInfo Endpoint, so all Claims returned MUST be in the ID Token.

To validate the ID Token received, the Client MUST do the following: The Client MUST validate that the value of the iss (issuer) Claim is https://self-issued.me. If iss contains a different value, the ID Token is not Self-Issued, and instead it MUST be validated according to . The Client MUST validate that the aud (audience) Claim contains the value of the redirect_uri that the Client sent in the Authentication Request as an audience. The Client MUST validate the signature of the ID Token according to JWS using the algorithm specified in the alg Header Parameter of the JOSE Header, using the key in the sub_jwk Claim; the key is a bare key in JWK format (not an X.509 certificate value). The alg value SHOULD be the default of RS256. It MAY also be ES256. The Client MUST validate that the sub Claim value is the base64url-encoded representation of the thumbprint of the key in the sub_jwk Claim, as specified in . The current time MUST be before the time represented by the exp Claim (possibly allowing for some small leeway to account for clock skew). The iat Claim can be used to reject tokens that were issued too far away from the current time, limiting the amount of time that nonces need to be stored to prevent attacks. The acceptable range is Client specific. A nonce Claim MUST be present and its value checked to verify that it is the same value as the one that was sent in the Authentication Request. The Client SHOULD check the nonce value for replay attacks. The precise method for detecting replay attacks is Client specific.

The following is a non-normative example of a base64url-decoded Self-Issued ID Token (with line wraps within values for display purposes only):

A Subject Identifier is a locally unique and never reassigned identifier within the Issuer for the End-User, which is intended to be consumed by the Client. Two Subject Identifier types are defined by this specification: This provides the same sub (subject) value to all Clients. It is the default if the provider has no subject_types_supported element in its discovery document. This provides a different sub value to each Client, so as not to enable Clients to correlate the End-User's activities without permission. The OpenID Provider's Discovery document MUST list its supported Subject Identifier types in the subject_types_supported element. If there is more than one type listed in the array, the Client MAY elect to provide its preferred identifier type using the subject_type parameter during Registration.

When pairwise Subject Identifiers are used, the OpenID Provider MUST calculate a unique sub (subject) value for each Sector Identifier. The Subject Identifier value MUST NOT be reversible by any party other than the OpenID Provider. Providers that use pairwise sub values and support Dynamic Client Registration SHOULD use the sector_identifier_uri parameter. It provides a way for a group of websites under common administrative control to have consistent pairwise sub values independent of the individual domain names. It also provides a way for Clients to change redirect_uri domains without having to reregister all of their users. If the Client has not provided a value for sector_identifier_uri in Dynamic Client Registration, the Sector Identifier used for pairwise identifier calculation is the host component of the registered redirect_uri. If there are multiple hostnames in the registered redirect_uris, the Client MUST register a sector_identifier_uri. When a sector_identifier_uri is provided, the host component of that URL is used as the Sector Identifier for the pairwise identifier calculation. The value of the sector_identifier_uri MUST be a URL using the https scheme that points to a JSON file containing an array of redirect_uri values. The values of the registered redirect_uris MUST be included in the elements of the array. Any algorithm with the following properties can be used by OpenID Providers to calculate pairwise Subject Identifiers: The Subject Identifier value MUST NOT be reversible by any party other than the OpenID Provider. Distinct Sector Identifier values MUST result in distinct Subject Identifier values. The algorithm MUST be deterministic. Three example methods are: The Sector Identifier can be concatenated with a local account ID and a salt value that is kept secret by the Provider. The concatenated string is then hashed using an appropriate algorithm. Calculate sub = SHA-256 ( sector_identifier || local_account_id || salt ). The Sector Identifier can be concatenated with a local account ID and a salt value that is kept secret by the Provider. The concatenated string is then encrypted using an appropriate algorithm. Calculate sub = AES-128 ( sector_identifier || local_account_id || salt ). The Issuer creates a Globally Unique Identifier (GUID) for the pair of Sector Identifier and local account ID and stores this value.

This section defines a set of Client Authentication methods that are used by Clients to authenticate to the Authorization Server when using the Token Endpoint. During Client Registration, the RP (Client) MAY register a Client Authentication method. If no method is registered, the default method is client_secret_basic. These Client Authentication methods are: Clients that have received a client_secret value from the Authorization Server authenticate with the Authorization Server in accordance with Section 2.3.1 of OAuth 2.0 using the HTTP Basic authentication scheme. Clients that have received a client_secret value from the Authorization Server, authenticate with the Authorization Server in accordance with Section 2.3.1 of OAuth 2.0 by including the Client Credentials in the request body. Clients that have received a client_secret value from the Authorization Server create a JWT using an HMAC SHA algorithm, such as HMAC SHA-256. The HMAC (Hash-based Message Authentication Code) is calculated using the octets of the UTF-8 representation of the client_secret as the shared key. The Client authenticates in accordance with JSON Web Token (JWT) Profile for OAuth 2.0 Client Authentication and Authorization Grants and Assertion Framework for OAuth 2.0 Client Authentication and Authorization Grants. The JWT MUST contain the following REQUIRED Claim Values and MAY contain the following OPTIONAL Claim Values: REQUIRED. Issuer. This MUST contain the client_id of the OAuth Client. REQUIRED. Subject. This MUST contain the client_id of the OAuth Client. REQUIRED. Audience. The aud (audience) Claim. Value that identifies the Authorization Server as an intended audience. The Authorization Server MUST verify that it is an intended audience for the token. The Audience SHOULD be the URL of the Authorization Server's Token Endpoint. REQUIRED. JWT ID. A unique identifier for the token, which can be used to prevent reuse of the token. These tokens MUST only be used once, unless conditions for reuse were negotiated between the parties; any such negotiation is beyond the scope of this specification. REQUIRED. Expiration time on or after which the JWT MUST NOT be accepted for processing. OPTIONAL. Time at which the JWT was issued. The JWT MAY contain other Claims. Any Claims used that are not understood MUST be ignored. The authentication token MUST be sent as the value of the client_assertion parameter. The value of the client_assertion_type parameter MUST be "urn:ietf:params:oauth:client-assertion-type:jwt-bearer", per . Clients that have registered a public key sign a JWT using that key. The Client authenticates in accordance with JSON Web Token (JWT) Profile for OAuth 2.0 Client Authentication and Authorization Grants and Assertion Framework for OAuth 2.0 Client Authentication and Authorization Grants. The JWT MUST contain the following REQUIRED Claim Values and MAY contain the following OPTIONAL Claim Values: REQUIRED. Issuer. This MUST contain the client_id of the OAuth Client. REQUIRED. Subject. This MUST contain the client_id of the OAuth Client. REQUIRED. Audience. The aud (audience) Claim. Value that identifies the Authorization Server as an intended audience. The Authorization Server MUST verify that it is an intended audience for the token. The Audience SHOULD be the URL of the Authorization Server's Token Endpoint. REQUIRED. JWT ID. A unique identifier for the token, which can be used to prevent reuse of the token. These tokens MUST only be used once, unless conditions for reuse were negotiated between the parties; any such negotiation is beyond the scope of this specification. REQUIRED. Expiration time on or after which the JWT MUST NOT be accepted for processing. OPTIONAL. Time at which the JWT was issued. The JWT MAY contain other Claims. Any Claims used that are not understood MUST be ignored. The authentication token MUST be sent as the value of the client_assertion parameter. The value of the client_assertion_type parameter MUST be "urn:ietf:params:oauth:client-assertion-type:jwt-bearer", per .

For example (with line wraps within values for display purposes only):

The Client does not authenticate itself at the Token Endpoint, either because it uses only the Implicit Flow (and so does not use the Token Endpoint) or because it is a Public Client with no Client Secret or other authentication mechanism.

Depending on the transport through which the messages are sent, the integrity of the message might not be guaranteed and the originator of the message might not be authenticated. To mitigate these risks, ID Token, UserInfo Response, Request Object, and Client Authentication JWT values can utilize JSON Web Signature (JWS) to sign their contents. To achieve message confidentiality, these values can also use JSON Web Encryption (JWE) to encrypt their contents. When the message is both signed and encrypted, it MUST be signed first and then encrypted, per , with the result being a Nested JWT, as specified in . Note that all JWE encryption methods perform integrity checking. The OP advertises its supported signing and encryption algorithms in its Discovery document, or may supply this information by other means. The RP declares its required signing and encryption algorithms in its Dynamic Registration request, or may communicate this information by other means. The OP advertises its public keys via its Discovery document, or may supply this information by other means. The RP declares its public keys via its Dynamic Registration request, or may communicate this information by other means.

The signing party MUST select a signature algorithm based on the algorithms supported by the recipient. When using RSA or ECDSA Signatures, the alg Header Parameter value of the JOSE Header MUST be set to an appropriate algorithm as defined in JSON Web Algorithms. The private key used to sign the content MUST be associated with a public key used for signature verification published by the sender in its JWK Set document. If there are multiple keys in the referenced JWK Set document, a kid value MUST be provided in the JOSE Header. The key usage of the respective keys MUST support signing. When using MAC-based signatures, the alg Header Parameter value of the JOSE Header MUST be set to a MAC algorithm, as defined in JSON Web Algorithms. The MAC key used is the octets of the UTF-8 representation of the client_secret value. See for a discussion of entropy requirements for client_secret values. Symmetric signatures MUST NOT be used by public (non-confidential) Clients because of their inability to keep secrets. See for Security Considerations about the need for signed requests.

Rotation of signing keys can be accomplished with the following approach. The signer publishes its keys in a JWK Set at its jwks_uri location and includes the kid of the signing key in the JOSE Header of each message to indicate to the verifier which key is to be used to validate the signature. Keys can be rolled over by periodically adding new keys to the JWK Set at the jwks_uri location. The signer can begin using a new key at its discretion and signals the change to the verifier using the kid value. The verifier knows to go back to the jwks_uri location to re-retrieve the keys when it sees an unfamiliar kid value. The JWK Set document at the jwks_uri SHOULD retain recently decommissioned signing keys for a reasonable period of time to facilitate a smooth transition.

The encrypting party MUST select an encryption algorithm based on the algorithms supported by the recipient. The public key to which the content was encrypted MUST be a public key used for encryption published by the recipient in its JWK Set document. If there are multiple keys in the referenced JWK Set document, a kid value MUST be provided in the JOSE Header. Use the supported RSA encryption algorithm to encrypt a random Content Encryption Key to be used for encrypting the signed JWT. The key usage of the respective keys MUST include encryption. Create an ephemeral Elliptic Curve public key for the epk element of the JOSE Header. The other public key used for the key agreement computation MUST be a public key published by the recipient in its JWK Set document. If there are multiple keys in the referenced JWK Set document, a kid value MUST be provided in the JOSE Header. Use the ECDH-ES algorithm to agree upon a Content Encryption Key to be used for encrypting the signed JWT. The key usage of the respective keys MUST support encryption. The symmetric encryption key is derived from the client_secret value by using the left-most bits of a truncated SHA-2 hash of the octets of the UTF-8 representation of the client_secret. For keys of 256 or fewer bits, SHA-256 is used; for keys of 257-384 bits, SHA-384 is used; for keys of 385-512 bits, SHA-512 is used. The hash value MUST be truncated retaining the left-most bits to the appropriate bit length for the AES key wrapping or direct encryption algorithm used, for instance, truncating the SHA-256 hash to 128 bits for A128KW. If a symmetric key with greater than 512 bits is needed, a different method of deriving the key from the client_secret would have to be defined by an extension. Symmetric encryption MUST NOT be used by public (non-confidential) Clients because of their inability to keep secrets. See for Security Considerations about the need for encrypted requests.

Rotating encryption keys necessarily uses a different process than the one for signing keys because the encrypting party starts the process and thus cannot rely on a change in kid as a signal that keys need to change. The encrypting party still uses the kid Header Parameter in the JWE to tell the decrypting party which private key to use to decrypt, however, the encrypting party needs to first select the most appropriate key from those provided in the JWK Set at the recipient's jwks_uri location. To rotate keys, the decrypting party can publish new keys at its jwks_uri location and remove from the JWK Set those that are being decommissioned. The jwks_uri SHOULD include a Cache-Control header in the response that contains a max-age directive, as defined in RFC 7234, which enables the encrypting party to safely cache the JWK Set and not have to re-retrieve the document for every encryption event. The decrypting party SHOULD remove decommissioned keys from the JWK Set referenced by jwks_uri but retain them internally for some reasonable period of time, coordinated with the cache duration, to facilitate a smooth transition between keys by allowing the encrypting party some time to obtain the new keys. The cache duration SHOULD also be coordinated with the issuance of new signing keys, as described in .

OpenID Connect defines the following scope value to request offline access: OPTIONAL. This scope value requests that an OAuth 2.0 Refresh Token be issued that can be used to obtain an Access Token that grants access to the End-User's UserInfo Endpoint even when the End-User is not present (not logged in). When offline access is requested, a prompt parameter value of consent MUST be used unless other conditions for processing the request permitting offline access to the requested resources are in place. The OP MUST always obtain consent to returning a Refresh Token that enables offline access to the requested resources. A previously saved user consent is not always sufficient to grant offline access. Upon receipt of a scope parameter containing the offline_access value, the Authorization Server: MUST ensure that the prompt parameter contains consent unless other conditions for processing the request permitting offline access to the requested resources are in place; unless one or both of these conditions are fulfilled, then it MUST ignore the offline_access request, MUST ignore the offline_access request unless the Client is using a response_type value that would result in an Authorization Code being returned, MUST explicitly receive or have consent for offline access when the registered application_type is web, SHOULD explicitly receive or have consent for offline access when the registered application_type is native. The use of Refresh Tokens is not exclusive to the offline_access use case. The Authorization Server MAY grant Refresh Tokens in other contexts that are beyond the scope of this specification.

A request to the Token Endpoint can also use a Refresh Token by using the grant_type value refresh_token, as described in Section 6 of OAuth 2.0. This section defines the behaviors for OpenID Connect Authorization Servers when Refresh Tokens are used.

To refresh an Access Token, the Client MUST authenticate to the Token Endpoint using the authentication method registered for its client_id, as documented in . The Client sends the parameters via HTTP POST to the Token Endpoint using Form Serialization, per .

The following is a non-normative example of a Refresh Request (with line wraps within values for display purposes only):

The Authorization Server MUST validate the Refresh Token, MUST verify that it was issued to the Client, and must verify that the Client successfully authenticated it has a Client Authentication method.

Upon successful validation of the Refresh Token, the response body is the Token Response of except that it might not contain an id_token. If an ID Token is returned as a result of a token refresh request, the following requirements apply: its iss Claim Value MUST be the same as in the ID Token issued when the original authentication occurred, its sub Claim Value MUST be the same as in the ID Token issued when the original authentication occurred, its iat Claim MUST represent the time that the new ID Token is issued, its aud Claim Value MUST be the same as in the ID Token issued when the original authentication occurred, if the ID Token contains an auth_time Claim, its value MUST represent the time of the original authentication - not the time that the new ID token is issued, if the implementation is using extensions (which are beyond the scope of this specification) that result in the azp (authorized party) Claim being present, those extensions might specify that its azp Claim Value MUST be the same as in the ID Token issued when the original authentication occurred; likewise, they might specify that if no azp Claim was present in the original ID Token, one MUST NOT be present in the new ID Token, it SHOULD NOT have a nonce Claim, even when the ID Token issued at the time of the original authentication contained nonce; however, if it is present, its value MUST be the same as in the ID Token issued at the time of the original authentication, and otherwise, the same rules apply as apply when issuing an ID Token at the time of the original authentication.

The following is a non-normative example of a Refresh Response:

If the Refresh Request is invalid or unauthorized, the Authorization Server returns the Token Error Response as defined in Section 5.2 of OAuth 2.0.

Messages are serialized using one of the following methods: Query String Serialization Form Serialization JSON Serialization This section describes the syntax of these serialization methods; other sections describe when they can and must be used. Note that not all methods can be used for all messages.

In order to serialize the parameters using the Query String Serialization, the Client constructs the string by adding the parameters and values to the query component of a URL using the application/x-www-form-urlencoded format as defined by . Query String Serialization is typically used in HTTP GET requests. The same serialization method is also used when adding parameters to the fragment component of a URL.

The following is a non-normative example of this serialization (with line wraps within values for display purposes only):

Parameters and their values are Form Serialized by adding the parameter names and values to the entity body of the HTTP request using the application/x-www-form-urlencoded format as defined by . Form Serialization is typically used in HTTP POST requests.

The following is a non-normative example of this serialization (with line wraps within values for display purposes only):

The parameters are serialized into a JSON object structure by adding each parameter at the highest structure level. Parameter names and string values are represented as JSON strings. Numerical values are represented as JSON numbers. Boolean values are represented as JSON booleans. Omitted parameters and parameters with no value SHOULD be omitted from the object and not represented by a JSON null value, unless otherwise specified. A parameter MAY have a JSON object or a JSON array as its value.

The following is a non-normative example of this serialization:

Processing some OpenID Connect messages requires comparing values in the messages to known values. For example, the Claim Names returned by the UserInfo Endpoint might be compared to specific Claim Names such as sub. Comparing Unicode strings, however, has significant security implications. Therefore, comparisons between JSON strings and other Unicode strings MUST be performed as specified below: Remove any JSON applied escaping to produce an array of Unicode code points. Unicode Normalization MUST NOT be applied at any point to either the JSON string or to the string it is to be compared against. Comparisons between the two strings MUST be performed as a Unicode code point to code point equality comparison. In several places, this specification uses space-delimited lists of strings. In all such cases, a single ASCII space character (0x20) MUST be used as the delimiter.

This specification defines features used by both Relying Parties and OpenID Providers. It is expected that some OpenID Providers will require static, out-of-band configuration of RPs using them, whereas others will support dynamic usage by RPs without a pre-established relationship between them. For that reason, the mandatory-to-implement features for OPs are listed below in two groups: the first for all OPs and the second for "Dynamic" OpenID Providers.

All OpenID Providers MUST implement the following features defined in this specification. This list augments the set of features that are already listed elsewhere as being "REQUIRED" or are described with a "MUST", and so is not, by itself, a comprehensive set of implementation requirements for OPs. OPs MUST support signing ID Tokens with the RSA SHA-256 algorithm (an alg value of RS256), unless the OP only supports returning ID Tokens from the Token Endpoint (as is the case for the Authorization Code Flow) and only allows Clients to register specifying none as the requested ID Token signing algorithm. OPs MUST support the prompt parameter, as defined in , including the specified user interface behaviors such as none and login. OPs MUST support the display parameter, as defined in . (Note that the minimum level of support required for this parameter is simply that its use must not result in an error.) OPs MUST support requests for preferred languages and scripts for the user interface and for Claims via the ui_locales and claims_locales request parameters, as defined in . (Note that the minimum level of support required for these parameters is simply to have their use not result in errors.) OPs MUST support returning the time at which the End-User authenticated via the auth_time Claim, when requested, as defined in . OPs MUST support enforcing a maximum authentication age via the max_age parameter, as defined in . OPs MUST support requests for specific Authentication Context Class Reference values via the acr_values parameter, as defined in . (Note that the minimum level of support required for this parameter is simply to have its use not result in an error.)

In addition to the features listed above, OpenID Providers supporting dynamic establishment of relationships with RPs that they do not have a pre-configured relationship with MUST also implement the following features defined in this and related specifications. These OpenID Providers MUST support the id_token Response Type and all that are not Self-Issued OPs MUST also support the code and id_token token Response Types. These OPs MUST support Discovery, as defined in OpenID Connect Discovery 1.0. These OPs MUST support Dynamic Client Registration, as defined in OpenID Connect Dynamic Client Registration 1.0. All dynamic OPs that issue Access Tokens MUST support the UserInfo Endpoint, as defined in . (Self-Issued OPs do not issue Access Tokens.) These OPs MUST publish their public keys as bare JWK keys (which MAY also be accompanied by X.509 representations of those keys). These OPs MUST support requests made using a Request Object value that is retrieved from a Request URI that is provided with the request_uri parameter, as defined in .

Some OpenID Connect installations can use a pre-configured set of OpenID Providers and/or Relying Parties. In those cases, it might not be necessary to support dynamic discovery of information about identities or services or dynamic registration of Clients. However, if installations choose to support unanticipated interactions between Relying Parties and OpenID Providers that do not have pre-configured relationships, they SHOULD accomplish this by implementing the facilities defined in the OpenID Connect Discovery 1.0 and OpenID Connect Dynamic Client Registration 1.0 specifications.

In general, it is up to Relying Parties which features they use when interacting with OpenID Providers. However, some choices are dictated by the nature of their OAuth Client, such as whether it is a Confidential Client, capable of keeping secrets, in which case the Authorization Code Flow may be appropriate, or whether it is a Public Client, for instance, a User Agent Based Application or a statically registered Native Application, in which case the Implicit Flow may be appropriate. When using OpenID Connect features, those listed as being "REQUIRED" or are described with a "MUST" are mandatory to implement, when used by a Relying Party. Likewise, those features that are described as "OPTIONAL" need not be used or supported unless they provide value in the particular application context. Finally, when interacting with OpenID Providers that support Discovery, the OP's Discovery document can be used to dynamically determine which OP features are available for use by the RP.

When using the Authorization Code or Hybrid flows, an ID Token is returned from the Token Endpoint in response to a Token Request using an Authorization Code. Some implementations may choose to encode state about the ID Token to be returned in the Authorization Code value. Others may use the Authorization Code value as an index into a database storing this state.

The nonce parameter value needs to include per-session state and be unguessable to attackers. One method to achieve this for Web Server Clients is to store a cryptographically random value as an HttpOnly session cookie and use a cryptographic hash of the value as the nonce parameter. In that case, the nonce in the returned ID Token is compared to the hash of the session cookie to detect ID Token replay by third parties. A related method applicable to JavaScript Clients is to store the cryptographically random value in HTML5 local storage and use a cryptographic hash of this value.

When response parameters are returned in the Redirection URI fragment value, the Client needs to have the User Agent parse the fragment encoded values and pass them to on to the Client's processing logic for consumption. User Agents that have direct access to cryptographic APIs may be able to be self-contained, for instance, with all Client code being written in JavaScript. However, if the Client does not run entirely in the User Agent, one way to achieve this is to post them to a Web Server Client for validation. The following is an example of a JavaScript file that a Client might host at its redirect_uri. This is loaded by the redirect from the Authorization Server. The fragment component is parsed and then sent by POST to a URI that will validate and use the information received.

Following is a non-normative example of a Redirect URI response: // First, parse the query string var params = {}, postBody = location.hash.substring(1), regex = /([^&=]+)=([^&]*)/g, m; while (m = regex.exec(postBody)) { params[decodeURIComponent(m[1])] = decodeURIComponent(m[2]); } // And send the token over to the server var req = new XMLHttpRequest(); // using POST so query isn't logged req.open('POST', 'https://' + window.location.host + '/catch_response', true); req.setRequestHeader('Content-Type', 'application/x-www-form-urlencoded'); req.onreadystatechange = function (e) { if (req.readyState == 4) { if (req.status == 200) { // If the response from the POST is 200 OK, perform a redirect window.location = 'https://' + window.location.host + '/redirect_after_login' } // if the OAuth response is invalid, generate an error message else if (req.status == 400) { alert('There was an error processing the token') } else { alert('Something other than 200 was returned') } } }; req.send(postBody); ]]>

NOTE: Potential compatibility issues that were previously described in the original version of this specification have since been addressed.

These related OPTIONAL specifications MAY be used in combination with this specification to provide additional functionality: OpenID Connect Discovery 1.0 - Defines how Relying Parties dynamically discover information about OpenID Providers OpenID Connect Dynamic Client Registration 1.0 - Defines how Relying Parties dynamically register with OpenID Providers OAuth 2.0 Form Post Response Mode - Defines how to return OAuth 2.0 Authorization Response parameters (including OpenID Connect Authentication Response parameters) using HTML form values that are auto-submitted by the User Agent using HTTP POST OpenID Connect RP-Initiated Logout 1.0 - Defines how a Relying Party requests that an OpenID Provider log out the End-User OpenID Connect Session Management 1.0 - Defines how to manage OpenID Connect sessions, including postMessage-based logout and RP-initiated logout functionality OpenID Connect Front-Channel Logout 1.0 - Defines a front-channel logout mechanism that does not use an OP iframe on RP pages OpenID Connect Back-Channel Logout 1.0 - Defines a logout mechanism that uses direct back-channel communication between the OP and RPs being logged out These implementer's guides are intended to serve as self-contained references for implementers of basic Web-based Relying Parties: OpenID Connect Basic Client Implementer's Guide 1.0 - Implementer's guide containing a subset of this specification that is intended for use by basic Web-based Relying Parties using the OAuth Authorization Code Flow OpenID Connect Implicit Client Implementer's Guide 1.0 - Implementer's guide containing a subset of this specification that is intended for use by basic Web-based Relying Parties using the OAuth Implicit Flow

This specification references the security considerations defined in Section 10 of OAuth 2.0, and Section 5 of OAuth 2.0 Bearer Token Usage. Furthermore, the OAuth 2.0 Threat Model and Security Considerations specification provides an extensive list of threats and controls that apply to this specification as well, given that it is based upon OAuth 2.0. ISO/IEC 29115 also provides threats and controls that implementers need to take into account. Implementers are highly advised to read these references in detail and apply the countermeasures described therein. In addition, the following list of attack vectors and remedies are also considered.

If appropriate measures are not taken, a request might be disclosed to an attacker, posing security and privacy threats. In addition to what is stated in Section 5.1.1 of , this standard provides a way to provide the confidentiality of the request end to end through the use of request or request_uri parameters, where the content of the request is an encrypted JWT with the appropriate key and cipher. This protects even against a compromised User Agent in the case of indirect request.

A malicious Server might masquerade as the legitimate server using various means. To detect such an attack, the Client needs to authenticate the server. In addition to what is stated in Section 5.1.2 of , this standard provides a way to authenticate the Server through either the use of Signed or Encrypted JWTs with an appropriate key and cipher.

An Attacker might generate a bogus token or modify the token contents (such as Claims values or the signature) of an existing parseable token, causing the RP to grant inappropriate access to the Client. For example, an Attacker might modify the parseable token to extend the validity period; a Client might modify the parseable token to have access to information that they should not be able to view. There are two ways to mitigate this attack: The token can be digitally signed by the OP. The Relying Party SHOULD validate the digital signature to verify that it was issued by a legitimate OP. The token can be sent over a protected channel such as TLS. See for more information on using TLS. In this specification, the token is always sent over a TLS protected channel. Note however, that this measure is only a defense against third party attackers and is not applicable to the case where the Client is the attacker.

Access Tokens are credentials used to access Protected Resources, as defined in Section 1.4 of OAuth 2.0. Access Tokens represent an End-User's authorization and MUST NOT be exposed to unauthorized parties.

The server response might contain authentication data and Claims that include sensitive Client information. Disclosure of the response contents can make the Client vulnerable to other types of attacks. The server response disclosure can be mitigated in the following two ways: Using the code Response Type. The response is sent over a TLS protected channel, where the Client is authenticated by the client_id and client_secret. For other Response Types, the signed response can be encrypted with the Client's public key or a shared secret as an encrypted JWT with an appropriate key and cipher.

A response might be repudiated by the server if the proper mechanisms are not in place. For example, if a Server does not digitally sign a response, the Server can claim that it was not generated through the services of the Server. To mitigate this threat, the response MAY be digitally signed by the Server using a key that supports non-repudiation. The Client SHOULD validate the digital signature to verify that it was issued by a legitimate Server and its integrity is intact.

Since it is possible for a compromised or malicious Client to send a request to the wrong party, a Client that was authenticated using only a bearer token can repudiate any transaction. To mitigate this threat, the Server MAY require that the request be digitally signed by the Client using a key that supports non-repudiation. The Server SHOULD validate the digital signature to verify that it was issued by a legitimate Client and its integrity is intact.

An Attacker uses the Access Token generated for one resource to obtain access to a second resource. To mitigate this threat, the Access Token SHOULD be audience and scope restricted. One way of implementing it is to include the identifier of the resource for whom it was generated as audience. The resource verifies that incoming tokens include its identifier as the audience of the token.

An Attacker attempts to use a one-time use token such as an Authorization Code that has already been used once with the intended Resource. To mitigate this threat, the token SHOULD include a timestamp and a short validity lifetime. The Relying Party then checks the timestamp and lifetime values to ensure that the token is currently valid. Alternatively, the server MAY record the state of the use of the token and check the status for each request.

In addition to the attack patterns described in Section 4.4.1.1 of , an Authorization Code can be captured in the User Agent where the TLS session is terminated if the User Agent is infected by malware. However, capturing it is not useful as long as either Client Authentication or an encrypted response is used.

Token Substitution is a class of attacks in which a malicious user swaps various tokens, including swapping an Authorization Code for a legitimate user with another token that the attacker has. One means of accomplishing this is for the attacker to copy a token out one session and use it in an HTTP message for a different session, which is easy to do when the token is available to the browser; this is known as the "cut and paste" attack. The Implicit Flow of OAuth 2.0 is not designed to mitigate this risk. In Section 10.16, it normatively requires that any use of the authorization process as a form of delegated End-User authentication to the Client MUST NOT use the Implicit Flow without employing additional security mechanisms that enable the Client to determine whether the ID Token and Access Token were issued for its use. In OpenID Connect, this is mitigated through mechanisms provided through the ID Token. The ID Token is a signed security token that provides Claims such as iss (issuer), sub (subject), aud (audience), at_hash (access token hash), and c_hash (code hash). Using the ID Token, the Client is capable of detecting the Token Substitution Attack. The c_hash in the ID Token enables Clients to prevent Authorization Code substitution. The at_hash in the ID Token enables Clients to prevent Access Token substitution. Also, a malicious user may attempt to impersonate a more privileged user by subverting the communication channel between the Authorization Endpoint and Client, or the Token Endpoint and Client, for example by swapping the Authorization Code or reordering the messages, to convince the Token Endpoint that the attacker's authorization grant corresponds to a grant sent on behalf of a more privileged user. For the HTTP binding defined by this specification, the responses to Token Requests are bound to the corresponding requests by message order in HTTP, as both the response containing the token and requests are protected by TLS, which will detect and prevent packet reordering. When designing another binding of this specification to a protocol incapable of strongly binding Token Endpoint requests to responses, additional mechanisms to address this issue MUST be utilized. One such mechanism could be to include an ID Token with a c_hash Claim in the token request and response.

A timing attack enables the attacker to obtain an unnecessary large amount of information through the elapsed time differences in the code paths taken by successful and unsuccessful decryption operations or successful and unsuccessful signature validation of a message. It can be used to reduce the effective key length of the cipher used. Implementations SHOULD NOT terminate the validation process at the instant of the finding an error but SHOULD continue running until all the octets have been processed to avoid this attack.

There are various crypto related attacks possible depending on the method used for encryption and signature / integrity checking. Implementers need to consult the Security Considerations for the JWT specification and specifications that it references to avoid the vulnerabilities identified in these specifications.

Signatures over encrypted text are not considered valid in many jurisdictions. Therefore, for integrity and non-repudiation, this specification requires signing the plain text JSON Claims, when signing is performed. If both signing and encryption are desired, it is performed on the JWS containing the signed Claims, with the result being a Nested JWT, as specified in . Note that since all JWE encryption algorithms provide integrity protection, there is no need to separately sign the encrypted content.

OpenID Connect supports multiple Issuers per Host and Port combination. The issuer returned by discovery MUST exactly match the value of iss in the ID Token. OpenID Connect treats the path component of any Issuer URI as being part of the Issuer Identifier. For instance, the subject "1234" with an Issuer Identifier of "https://example.com" is not equivalent to the subject "1234" with an Issuer Identifier of "https://example.com/sales". It is RECOMMENDED that only a single Issuer per host be used. However, if a host supports multiple tenants, multiple Issuers for that host may be needed.

In the Implicit Flow, the Access Token is returned in the fragment component of the Client's redirect_uri through HTTPS, thus it is protected between the OP and the User Agent, and between the User Agent and the RP. The only place it can be captured is the User Agent where the TLS session is terminated, which is possible if the User Agent is infected by malware or under the control of a malicious party.

Implementations MUST support TLS. Which version(s) ought to be implemented will vary over time, and depend on the widespread deployment and known security vulnerabilities at the time of implementation. Implementations SHOULD follow the guidance in BCP 195 , which provides recommendations and requirements for improving the security of deployed services that use TLS. To protect against information disclosure and tampering, confidentiality protection MUST be applied using TLS with a ciphersuite that provides confidentiality and integrity protection. Whenever TLS is used, a TLS server certificate check MUST be performed, per RFC 6125.

Access Tokens might not be revocable by the Authorization Server. Access Token lifetimes SHOULD therefore be kept to single use or very short lifetimes. If ongoing access to the UserInfo Endpoint or other Protected Resources is required, a Refresh Token can be used. The Client can then exchange the Refresh Token at the Token Endpoint for a fresh short-lived Access Token that can be used to access the resource. The Authorization Server SHOULD clearly identify long-term grants to the User during Authorization. The Authorization Server SHOULD provide a mechanism for the End-User to revoke Access Tokens and Refresh Tokens granted to a Client.

In and , keys are derived from the client_secret value. Thus, when used with symmetric signing or encryption operations, client_secret values MUST contain sufficient entropy to generate cryptographically strong keys. Also, client_secret values MUST also contain at least the minimum of number of octets required for MAC keys for the particular algorithm used. So for instance, for HS256, the client_secret value MUST contain at least 32 octets (and almost certainly SHOULD contain more, since client_secret values are likely to use a restricted alphabet).

In some situations, Clients might need to use signed requests to ensure that the desired request parameters are delivered to the OP without having been tampered with. For instance, the max_age and acr_values provide more assurance about the nature of the authentication performed when delivered in signed requests.

In some situations, knowing the contents of an OpenID Connect request can, in and of itself, reveal sensitive information about the End-User. For instance, knowing that the Client is requesting a particular Claim or that it is requesting that a particular authentication method be used can reveal sensitive information about the End-User. OpenID Connect enables requests to be encrypted to the OpenID Provider to prevent such potentially sensitive information from being revealed.

HTTP 307 redirects send a POST request to the party being redirected to that contains all the form data from the previous request. This can leak credentials intended for the OpenID Provider to the Relying Party. Therefore, HTTP 307 redirects MUST NOT be used when redirecting to the Redirection URI. Likewise, while HTTP 302 redirects are typically implemented in a way that does not do this, the use of HTTP 303 redirect is preferable, as it is defined not to do this.

Note that on iOS, multiple applications can register as handlers for a custom URI scheme, therefore it is not deterministic that the calling application will receive the Authentication Reply from the Self-Issued OpenID Provider. Use of a claimed URI is an alternative to using the openid: custom URI scheme.

The UserInfo Response typically contains Personally Identifiable Information (PII). As such, End-User consent for the release of the information for the specified purpose should be obtained at or prior to the authorization time in accordance with relevant regulations. The purpose of use is typically registered in association with the redirect_uris. Only necessary UserInfo data should be stored at the Client and the Client SHOULD associate the received data with the purpose of use statement.

The Resource Server SHOULD make End-Users' UserInfo access logs available to them so that they can monitor who accessed their data.

To protect the End-User from a possible correlation among Clients, the use of a Pairwise Pseudonymous Identifier (PPID) as the sub (subject) SHOULD be considered.

Offline access enables access to Claims when the user is not present, posing greater privacy risk than the Claims transfer when the user is present. Therefore, it is prudent to obtain explicit consent for offline access to resources. This specification mandates the use of the prompt parameter to obtain consent unless it is already known that the request complies with the conditions for processing the request in each jurisdiction. When an Access Token is returned via the User Agent using the Implicit Flow or Hybrid Flow, there is a greater risk of it being exposed to an attacker, who could later use it to access the UserInfo endpoint. If the Access Token does not enable offline access and the server can differentiate whether the Client request has been made offline or online, the risk will be substantially reduced. Therefore, this specification mandates ignoring the offline access request when the Access Token is transmitted through the User Agent. Note that differentiating between online and offline access from the server can be difficult especially for native clients. The server may well have to rely on heuristics. Also, the risk of exposure for the Access Token delivered through the User Agent for the Response Types of code token and token is the same. Thus, the implementations should be prepared to detect whether the Access Token was issued through the User Agent or directly from the Token Endpoint and deny offline access if the token was issued through the User Agent. Note that although these provisions require an explicit consent dialogue through the prompt parameter, the mere fact that the user pressed an "accept" button etc., might not constitute a valid consent. Developers should be aware that for the act of consent to be valid, typically, the impact of the terms have to be understood by the End-User, the consent must be freely given and not forced (i.e., other options have to be available), and the terms must fair and equitable. In general, it is advisable for the service to follow the required privacy principles in each jurisdiction and rely on other conditions for processing the request than simply explicit consent, as online self-service "explicit consent" often does not form a valid consent in some jurisdictions.

This specification registers the following Claims in the IANA "JSON Web Token Claims" registry established by .

Claim Name: name Claim Description: Full name Change Controller: OpenID Foundation Artifact Binding Working Group - openid-specs-ab@lists.openid.net Specification Document(s): of this document Claim Name: given_name Claim Description: Given name(s) or first name(s) Change Controller: OpenID Foundation Artifact Binding Working Group - openid-specs-ab@lists.openid.net Specification Document(s): of this document Claim Name: family_name Claim Description: Surname(s) or last name(s) Change Controller: OpenID Foundation Artifact Binding Working Group - openid-specs-ab@lists.openid.net Specification Document(s): of this document Claim Name: middle_name Claim Description: Middle name(s) Change Controller: OpenID Foundation Artifact Binding Working Group - openid-specs-ab@lists.openid.net Specification Document(s): of this document Claim Name: nickname Claim Description: Casual name Change Controller: OpenID Foundation Artifact Binding Working Group - openid-specs-ab@lists.openid.net Specification Document(s): of this document Claim Name: preferred_username Claim Description: Shorthand name by which the End-User wishes to be referred to Change Controller: OpenID Foundation Artifact Binding Working Group - openid-specs-ab@lists.openid.net Specification Document(s): of this document Claim Name: profile Claim Description: Profile page URL Change Controller: OpenID Foundation Artifact Binding Working Group - openid-specs-ab@lists.openid.net Specification Document(s): of this document Claim Name: picture Claim Description: Profile picture URL Change Controller: OpenID Foundation Artifact Binding Working Group - openid-specs-ab@lists.openid.net Specification Document(s): of this document Claim Name: website Claim Description: Web page or blog URL Change Controller: OpenID Foundation Artifact Binding Working Group - openid-specs-ab@lists.openid.net Specification Document(s): of this document Claim Name: email Claim Description: Preferred e-mail address Change Controller: OpenID Foundation Artifact Binding Working Group - openid-specs-ab@lists.openid.net Specification Document(s): of this document Claim Name: email_verified Claim Description: True if the e-mail address has been verified; otherwise false Change Controller: OpenID Foundation Artifact Binding Working Group - openid-specs-ab@lists.openid.net Specification Document(s): of this document Claim Name: gender Claim Description: Gender Change Controller: OpenID Foundation Artifact Binding Working Group - openid-specs-ab@lists.openid.net Specification Document(s): of this document Claim Name: birthdate Claim Description: Birthday Change Controller: OpenID Foundation Artifact Binding Working Group - openid-specs-ab@lists.openid.net Specification Document(s): of this document Claim Name: zoneinfo Claim Description: Time zone Change Controller: OpenID Foundation Artifact Binding Working Group - openid-specs-ab@lists.openid.net Specification Document(s): of this document Claim Name: locale Claim Description: Locale Change Controller: OpenID Foundation Artifact Binding Working Group - openid-specs-ab@lists.openid.net Specification Document(s): of this document Claim Name: phone_number Claim Description: Preferred telephone number Change Controller: OpenID Foundation Artifact Binding Working Group - openid-specs-ab@lists.openid.net Specification Document(s): of this document Claim Name: phone_number_verified Claim Description: True if the phone number has been verified; otherwise false Change Controller: OpenID Foundation Artifact Binding Working Group - openid-specs-ab@lists.openid.net Specification Document(s): of this document Claim Name: address Claim Description: Preferred postal address Change Controller: OpenID Foundation Artifact Binding Working Group - openid-specs-ab@lists.openid.net Specification Document(s): of this document Claim Name: updated_at Claim Description: Time the information was last updated Change Controller: OpenID Foundation Artifact Binding Working Group - openid-specs-ab@lists.openid.net Specification Document(s): of this document Claim Name: azp Claim Description: Authorized party - the party to which the ID Token was issued Change Controller: OpenID Foundation Artifact Binding Working Group - openid-specs-ab@lists.openid.net Specification Document(s): of this document Claim Name: nonce Claim Description: Value used to associate a Client session with an ID Token Change Controller: OpenID Foundation Artifact Binding Working Group - openid-specs-ab@lists.openid.net Specification Document(s): of this document Claim Name: auth_time Claim Description: Time when the authentication occurred Change Controller: OpenID Foundation Artifact Binding Working Group - openid-specs-ab@lists.openid.net Specification Document(s): of this document Claim Name: at_hash Claim Description: Access Token hash value Change Controller: OpenID Foundation Artifact Binding Working Group - openid-specs-ab@lists.openid.net Specification Document(s): of this document Claim Name: c_hash Claim Description: Code hash value Change Controller: OpenID Foundation Artifact Binding Working Group - openid-specs-ab@lists.openid.net Specification Document(s): of this document Claim Name: acr Claim Description: Authentication Context Class Reference Change Controller: OpenID Foundation Artifact Binding Working Group - openid-specs-ab@lists.openid.net Specification Document(s): of this document Claim Name: amr Claim Description: Authentication Methods References Change Controller: OpenID Foundation Artifact Binding Working Group - openid-specs-ab@lists.openid.net Specification Document(s): of this document Claim Name: sub_jwk Claim Description: Public key used to check the signature of an ID Token Change Controller: OpenID Foundation Artifact Binding Working Group - openid-specs-ab@lists.openid.net Specification Document(s): of this document Claim Name: _claim_names Claim Description: JSON object whose member names are the Claim Names for the Aggregated and Distributed Claims Change Controller: OpenID Foundation Artifact Binding Working Group - openid-specs-ab@lists.openid.net Specification Document(s): of this document Claim Name: _claim_sources Claim Description: JSON object whose member names are referenced by the member values of the _claim_names member Change Controller: OpenID Foundation Artifact Binding Working Group - openid-specs-ab@lists.openid.net Specification Document(s): of this document

This specification registers the following parameters in the IANA "OAuth Parameters" registry established by RFC 6749.

Parameter name: nonce Parameter usage location: Authorization Request Change controller: OpenID Foundation Artifact Binding Working Group - openid-specs-ab@lists.openid.net Specification document(s): of this document Related information: None Parameter name: display Parameter usage location: Authorization Request Change controller: OpenID Foundation Artifact Binding Working Group - openid-specs-ab@lists.openid.net Specification document(s): of this document Related information: None Parameter name: prompt Parameter usage location: Authorization Request Change controller: OpenID Foundation Artifact Binding Working Group - openid-specs-ab@lists.openid.net Specification document(s): of this document Related information: None Parameter name: max_age Parameter usage location: Authorization Request Change controller: OpenID Foundation Artifact Binding Working Group - openid-specs-ab@lists.openid.net Specification document(s): of this document Related information: None Parameter name: ui_locales Parameter usage location: Authorization Request Change controller: OpenID Foundation Artifact Binding Working Group - openid-specs-ab@lists.openid.net Specification document(s): of this document Related information: None Parameter name: claims_locales Parameter usage location: Authorization Request Change controller: OpenID Foundation Artifact Binding Working Group - openid-specs-ab@lists.openid.net Specification document(s): of this document Related information: None Parameter name: id_token_hint Parameter usage location: Authorization Request Change controller: OpenID Foundation Artifact Binding Working Group - openid-specs-ab@lists.openid.net Specification document(s): of this document Related information: None Parameter name: login_hint Parameter usage location: Authorization Request Change controller: OpenID Foundation Artifact Binding Working Group - openid-specs-ab@lists.openid.net Specification document(s): of this document Related information: None Parameter name: acr_values Parameter usage location: Authorization Request Change controller: OpenID Foundation Artifact Binding Working Group - openid-specs-ab@lists.openid.net Specification document(s): of this document Related information: None Parameter name: claims Parameter usage location: Authorization Request Change controller: OpenID Foundation Artifact Binding Working Group - openid-specs-ab@lists.openid.net Specification document(s): of this document Related information: None Parameter name: registration Parameter usage location: Authorization Request Change controller: OpenID Foundation Artifact Binding Working Group - openid-specs-ab@lists.openid.net Specification document(s): of this document Related information: None Parameter name: request Parameter usage location: Authorization Request Change controller: OpenID Foundation Artifact Binding Working Group - openid-specs-ab@lists.openid.net Specification document(s): of this document Related information: None Parameter name: request_uri Parameter usage location: Authorization Request Change controller: OpenID Foundation Artifact Binding Working Group - openid-specs-ab@lists.openid.net Specification document(s): of this document Related information: None Parameter name: id_token Parameter usage location: Authorization Response, Access Token Response Change controller: OpenID Foundation Artifact Binding Working Group - openid-specs-ab@lists.openid.net Specification document(s): of this document Related information: None

This specification registers the following errors in the IANA "OAuth Extensions Error" registry established by RFC 6749.

Error name: interaction_required Error usage location: Authorization Endpoint Related protocol extension: OpenID Connect Change controller: OpenID Foundation Artifact Binding Working Group - openid-specs-ab@lists.openid.net Specification document(s): of this document Error name: login_required Error usage location: Authorization Endpoint Related protocol extension: OpenID Connect Change controller: OpenID Foundation Artifact Binding Working Group - openid-specs-ab@lists.openid.net Specification document(s): of this document Error name: account_selection_required Error usage location: Authorization Endpoint Related protocol extension: OpenID Connect Change controller: OpenID Foundation Artifact Binding Working Group - openid-specs-ab@lists.openid.net Specification document(s): of this document Error name: consent_required Error usage location: Authorization Endpoint Related protocol extension: OpenID Connect Change controller: OpenID Foundation Artifact Binding Working Group - openid-specs-ab@lists.openid.net Specification document(s): of this document Error name: invalid_request_uri Error usage location: Authorization Endpoint Related protocol extension: OpenID Connect Change controller: OpenID Foundation Artifact Binding Working Group - openid-specs-ab@lists.openid.net Specification document(s): of this document Error name: invalid_request_object Error usage location: Authorization Endpoint Related protocol extension: OpenID Connect Change controller: OpenID Foundation Artifact Binding Working Group - openid-specs-ab@lists.openid.net Specification document(s): of this document Error name: request_not_supported Error usage location: Authorization Endpoint Related protocol extension: OpenID Connect Change controller: OpenID Foundation Artifact Binding Working Group - openid-specs-ab@lists.openid.net Specification document(s): of this document Error name: request_uri_not_supported Error usage location: Authorization Endpoint Related protocol extension: OpenID Connect Change controller: OpenID Foundation Artifact Binding Working Group - openid-specs-ab@lists.openid.net Specification document(s): of this document Error name: registration_not_supported Error usage location: Authorization Endpoint Related protocol extension: OpenID Connect Change controller: OpenID Foundation Artifact Binding Working Group - openid-specs-ab@lists.openid.net Specification document(s): of this document

This specification registers the following URI scheme in the IANA "Uniform Resource Identifier (URI) Schemes" registry established by RFC 7595.

Scheme name: openid Status: Permanent Applications/protocols that use this scheme name: OpenID Connect Contact: Michael B. Jones - michael_b_jones@hotmail.com Change controller: OpenID Foundation Artifact Binding Working Group - openid-specs-ab@lists.openid.net References: of this document

In many standards track documents several words are used to signify the requirements in the specification. These words are often capitalized. This document defines these words as they should be interpreted in IETF documents. This document specifies an Internet Best Current Practices for the Internet Community, and requests discussion and suggestions for improvements. JavaScript Object Notation (JSON) is a lightweight, text-based, language-independent data interchange format. It was derived from the ECMAScript Programming Language Standard. JSON defines a small set of formatting rules for the portable representation of structured data. This memo provides information for the Internet community. This document defines a date and time format for use in Internet protocols that is a profile of the ISO 8601 standard for representation of dates and times using the Gregorian calendar. ISO/IEC 10646-1 defines a large character set called the Universal Character Set (UCS) which encompasses most of the world's writing systems. The originally proposed encodings of the UCS, however, were not compatible with many current applications and protocols, and this has led to the development of UTF-8, the object of this memo. UTF-8 has the characteristic of preserving the full US-ASCII range, providing compatibility with file systems, parsers and other software that rely on US-ASCII values but are transparent to other values. This memo obsoletes and replaces RFC 2279. This document specifies the URI (Uniform Resource Identifier) scheme "tel". The "tel" URI describes resources identified by telephone numbers. This document obsoletes RFC 2806. [STANDARDS-TRACK] A Uniform Resource Identifier (URI) is a compact sequence of characters that identifies an abstract or physical resource. This specification defines the generic URI syntax and a process for resolving URI references that might be in relative form, along with guidelines and security considerations for the use of URIs on the Internet. The URI syntax defines a grammar that is a superset of all valid URIs, allowing an implementation to parse the common components of a URI reference without knowing the scheme-specific requirements of every possible identifier. This specification does not define a generative grammar for URIs; that task is performed by the individual specifications of each URI scheme. [STANDARDS-TRACK] This document specifies the Internet Message Format (IMF), a syntax for text messages that are sent between computer users, within the framework of "electronic mail" messages. This specification is a revision of Request For Comments (RFC) 2822, which itself superseded Request For Comments (RFC) 822, "Standard for the Format of ARPA Internet Text Messages", updating it to reflect current practice and incorporating incremental changes that were specified in other RFCs. [STANDARDS-TRACK] This document describes the structure, content, construction, and semantics of language tags for use in cases where it is desirable to indicate the language used in an information object. It also describes how to register values for use in language tags and the creation of user-defined extensions for private interchange. This document specifies an Internet Best Current Practices for the Internet Community, and requests discussion and suggestions for improvements. Many application technologies enable secure communication between two entities by means of Internet Public Key Infrastructure Using X.509 (PKIX) certificates in the context of Transport Layer Security (TLS). This document specifies procedures for representing and verifying the identity of application services in such interactions. [STANDARDS-TRACK] This document establishes an IANA registry for Level of Assurance (LoA) Profiles. The registry is intended to be used as an aid to discovering such LoA definitions in protocols that use an LoA concept, including Security Assertion Markup Language (SAML) 2.0 and OpenID Connect. This document is not an Internet Standards Track specification; it is published for informational purposes. The OAuth 2.0 authorization framework enables a third-party application to obtain limited access to an HTTP service, either on behalf of a resource owner by orchestrating an approval interaction between the resource owner and the HTTP service, or by allowing the third-party application to obtain access on its own behalf. This specification replaces and obsoletes the OAuth 1.0 protocol described in RFC 5849. [STANDARDS-TRACK] This specification describes how to use bearer tokens in HTTP requests to access OAuth 2.0 protected resources. Any party in possession of a bearer token (a "bearer") can use it to get access to the associated resources (without demonstrating possession of a cryptographic key). To prevent misuse, bearer tokens need to be protected from disclosure in storage and in transport. [STANDARDS-TRACK] This document gives additional security considerations for OAuth, beyond those in the OAuth 2.0 specification, based on a comprehensive threat model for the OAuth 2.0 protocol. This document is not an Internet Standards Track specification; it is published for informational purposes. JavaScript Object Notation (JSON) is a lightweight, text-based, language-independent data interchange format. It was derived from the ECMAScript Programming Language Standard. JSON defines a small set of formatting rules for the portable representation of structured data. This document removes inconsistencies with other specifications of JSON, repairs specification errors, and offers experience-based interoperability guidance. The Hypertext Transfer Protocol (HTTP) is a stateless application-level protocol for distributed, collaborative, hypertext information systems. This document provides an overview of HTTP architecture and its associated terminology, defines the "http" and "https" Uniform Resource Identifier (URI) schemes, defines the HTTP/1.1 message syntax and parsing requirements, and describes related security concerns for implementations. The Hypertext Transfer Protocol (HTTP) is a stateless \%application- level protocol for distributed, collaborative, hypertext information systems. This document defines the semantics of HTTP/1.1 messages, as expressed by request methods, request header fields, response status codes, and response header fields, along with the payload of messages (metadata and body content) and mechanisms for content negotiation. The Hypertext Transfer Protocol (HTTP) is a stateless \%application- level protocol for distributed, collaborative, hypertext information systems. This document defines HTTP caches and the associated header fields that control cache behavior or indicate cacheable response messages. This document formally deprecates Transport Layer Security (TLS) versions 1.0 (RFC 2246) and 1.1 (RFC 4346). Accordingly, those documents have been moved to Historic status. These versions lack support for current and recommended cryptographic algorithms and mechanisms, and various government and industry profiles of applications using TLS now mandate avoiding these old TLS versions. TLS version 1.2 became the recommended version for IETF protocols in 2008 (subsequently being obsoleted by TLS version 1.3 in 2018), providing sufficient time to transition away from older versions. Removing support for older versions from implementations reduces the attack surface, reduces opportunity for misconfiguration, and streamlines library and product maintenance. This document also deprecates Datagram TLS (DTLS) version 1.0 (RFC 4347) but not DTLS version 1.2, and there is no DTLS version 1.1. This document updates many RFCs that normatively refer to TLS version 1.0 or TLS version 1.1, as described herein. This document also updates the best practices for TLS usage in RFC 7525; hence, it is part of BCP 195. Transport Layer Security (TLS) and Datagram Transport Layer Security (DTLS) are used to protect data exchanged over a wide range of application protocols and can also form the basis for secure transport protocols. Over the years, the industry has witnessed several serious attacks on TLS and DTLS, including attacks on the most commonly used cipher suites and their modes of operation. This document provides the latest recommendations for ensuring the security of deployed services that use TLS and DTLS. These recommendations are applicable to the majority of use cases. RFC 7525, an earlier version of the TLS recommendations, was published when the industry was transitioning to TLS 1.2. Years later, this transition is largely complete, and TLS 1.3 is widely available. This document updates the guidance given the new environment and obsoletes RFC 7525. In addition, this document updates RFCs 5288 and 6066 in view of recent attacks.

markdavis@google.com

ken@unicode.org

NAT.Consulting Yubico independent Illumila NAT.Consulting Yubico independent Microsoft Ping Identity Nomura Research Institute, Ltd. Microsoft Ping Identity Nomura Research Institute, Ltd. Microsoft RTFM, Inc. Cisco Systems, Inc. Microsoft Microsoft Microsoft Ping Identity Salesforce Ping Identity Salesforce.com Microsoft Microsoft International Organization for Standardization International Organization for Standardization International Organization for Standardization International Organization for Standardization International Telecommunication Union IANA Google Google Facebook Microsoft IANA Opera Software ASA IANA IANA IANA University California Los Angeles (UCLA) The Unicode Consortium

Nomura Research Institute, Ltd. Ping Identity Microsoft Google Salesforce Nomura Research Institute, Ltd. Ping Identity Microsoft Google Salesforce This Glossary provides definitions, abbreviations, and explanations of terminology for information system security. The 334 pages of entries offer recommendations to improve the comprehensibility of written material that is generated in the Internet Standards Process (RFC 2026). The recommendations follow the principles that such writing should (a) use the same term or definition whenever the same concept is mentioned; (b) use terms in their plainest, dictionary sense; (c) use terms that are already well-established in open publications; and (d) avoid terms that either favor a particular vendor or favor a particular technology or mechanism over other, competing techniques that already exist or could be developed. This memo provides information for the Internet community. This document updates the guidelines and recommendations, as well as the IANA registration processes, for the definition of Uniform Resource Identifier (URI) schemes. It obsoletes RFC 4395. NAT.Consulting Yubico independent Google Disney NAT.Consulting Yubico independent Google Disney Microsoft Google Microsoft NAT.Consulting Yubico Google Microsoft NAT.Consulting Yubico Microsoft Microsoft independent Yubico Microsoft Ping Identity OpenID Foundation Six Apart, Ltd.

548 4th Street San Francisco CA 94107 USA david@sixapart.com http://www.sixapart.com/

Microsoft Corporation

One Microsoft Way, Building 40/5138 Redmond WA 98052 USA mbj@microsoft.com http://www.microsoft.com/

Independent

johnny.bufu@gmail.com

JanRain

5331 SW Macadam Ave. #375 Portland OR 97239 USA cygnus@janrain.com http://janrain.com/

Nomura Research Institute, Ltd.

Marunouchi Kitaguchi Building, 1-6-5 Marunouchi Chiyoda-ku Tokyo 100-0005 Japan n-sakimura@nri.co.jp http://www.nri.co.jp/

International Telecommunication Union Microsoft

mbj@microsoft.com https://self-issued.info/

Nomura Research Institute

n-sakimura@nri.co.jp https://nat.sakimura.org/

The following are non-normative examples of Authorization Requests with different response_type values and their responses (with line wraps within values for display purposes only):

The value of the id_token parameter is the ID Token, which is a signed JWT, containing three base64url-encoded segments separated by period ('.') characters. The first segment represents the JOSE Header. Base64url decoding it will result in the following set of Header Parameters:

The alg value represents the algorithm that was used to sign the JWT, in this case RS256, representing RSASSA-PKCS1-v1_5 using SHA-256. The kid value is a key identifier used in identifying the key to be used to verify the signature. If the kid value is unknown to the RP, it needs to retrieve the contents of the OP's JWK Set again to obtain the OP's current set of keys.

The second segment represents the Claims in the ID Token. Verifying and decoding the ID Token will yield the following Claims:

The third segment represents the ID Token signature, which is verified as described in .

Verifying and decoding the ID Token will yield the following Claims:

Verifying and decoding the ID Token will yield the following Claims:

Verifying and decoding the ID Token will yield the following Claims:

The following RSA public key, represented in JWK format, can be used to validate the ID Token signatures in the above examples (with line wraps within values for display purposes only):

As a successor version of OpenID, this specification heavily relies on ideas explored in OpenID Authentication 2.0. Please refer to Appendix C of OpenID Authentication 2.0 for the full list of the contributors for that specification. In addition, the OpenID Community would like to thank the following people for their contributions to this specification: Naveen Agarwal (Naveen.Agarwal@microsoft.com), Microsoft (was at Google) Amanda Anganes (aanganes@mitre.org), MITRE Casper Biering (cb@peercraft.com), Peercraft John Bradley (ve7jtb@ve7jtb.com), Yubico (was at Ping Identity) Tim Bray (tbray@textuality.com), independent (was at Google) Johnny Bufu (johnny.bufu@gmail.com), independent (was at Janrain) Brian Campbell (bcampbell@pingidentity.com), Ping Identity Blaine Cook (romeda@gmail.com), independent Breno de Medeiros (breno@google.com), Google Pamela Dingle (Pamela.Dingle@microsoft.com), Microsoft (was at Ping Identity) Vladimir Dzhuvinov (vladimir@connect2id.com), Connect2id (was at Nimbus Directory Services) George Fletcher (gffletch@aol.com), Capital One (was at AOL) Roland Hedberg (roland@catalogix.se), independent (was at University of Umeå) Ryo Ito (ryo.ito@mixi.co.jp), mixi, Inc. Edmund Jay (ejay@mgi1.com), Illumila Michael B. Jones (michael_b_jones@hotmail.com), independent (was at Microsoft) Torsten Lodderstedt (torsten@lodderstedt.net), yes.com (was at Deutsche Telekom) James Manger (James.H.Manger@team.telstra.com), Telstra Nov Matake (nov@matake.jp), independent Chuck Mortimore (charliemortimore@gmail.com), Disney (was at Salesforce) Anthony Nadalin (nadalin@prodigy.net), independent (was at Microsoft) Hideki Nara (hdknr@ic-tact.co.jp), Tact Communications Axel Nennker (axel.nennker@telekom.de), Deutsche Telekom David Recordon (recordond@gmail.com), independent (was at Facebook) Justin Richer (justin@bspk.io), Bespoke Engineering (was at MITRE) Nat Sakimura (nat@nat.consulting), NAT.Consulting (was at NRI) Luke Shepard (luke@lukeshepard.com), Facebook Andreas Åkre Solberg (andreas.solberg@uninett.no), UNINET Paul Tarjan (paul@paultarjan.com), Facebook

Copyright (c) 2023 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, patents, patent applications, or other proprietary rights that may cover technology that may be required to practice this specification.

[[ To be removed from the approved errata ]] -32 Fixed #1143: Changed values to value or values. Use IANA Time Zone Database for zoneinfo Claim values. Fixed #1159: Use TLS guidance from BCP 195. Fixed #1101: Discuss OP behaviors when unknown display or prompt values are received. Fixed #1050: The OP MAY omit Claims available from Claims Providers from _claim_names. Fixed #1117: It is not an error condition for a Claims Provider to not return a requested Claim. Fixed #1066: JWTs for Aggregated and Distributed Claims SHOULD contain an iss (issuer) Claim. Fixed #1026: Added Security Considerations about custom URI schemes on iOS. Fixed #989: Only iss and sub from the ID Token provide a stable identifier for the End-User. Fixed #1395: Stated that login decision with id_token_hint may involve other information. -31 Fixed #1048: Clarified how Implicit and Hybrid Error Response parameters are returned. Fixed #977: Return HTTP 400 (Bad Request) when the Response Mode is not supported. Fixed #1051: Deleted erroneous sentence about the claims parameter and non-standard Claims. Fixed #1115: Said that it is not an error condition to not return a requested Claim. Fixed #1169: Changed URL to URI in a section title. Fixed #1065: Clarified that not all Claims from utilized Claims Providers need be returned. Fixed #1112: Requested registration of the "openid:" URI scheme. Fixed #974: Removed use of RSA1_5. Fixed #978: Referenced previous versions. Fixed #1046: Augmented login_hint description. Fixed #1114: Clarified value. Updated contributor affiliations. -30 Fixed #1266 - Removed misleading self-issued language that seemed to imply that nonce is optional. Fixed #1251 - Referenced JWS definition of Base64url Encoding. Fixed #968: Made id_token_hint error treatment consistent. Fixed #973 and #1009 - Clarified that "azp" only occurs when extensions are used that are beyond the scope of this specification. Fixed #1025 - Clarified that "nonce" should not be present in ID Tokens issued in response to refresh requests. Fixed #1062 - Replaced confusing offline_access language. Fixed #980 - Specified the use of CORS at additional endpoints. -29 Updated logout spec references. Updated contributor affiliations. -28 Updated contributor affiliations. Updated many spec URLs from http to https. -27 Fixed #1087 - Insufficient description of id_token_hint processing and validation. -26 Fixed #1085 - Split RP-Initiated Logout into its own specification. Updated affiliations and acknowledgements. -25 Fixed #972 - Clarified nonce requirement in hybrid authentication request. Fixed #997 - Incorrect reference in Section 15.2. Fixed #970 - ID Token acr claim incorrectly specifies the level 0 of assurance. Fixed #982 - Error in JWT claim definitions for client authentication. Fixed #985 - Noted that the token_type value is case insensitive. Fixed #990 - UserInfo Error Response Example missing "Bearer" auth-scheme. Fixed #986 - Softening the 512 ASCII characters restriction. Fixed #993 - How to treat a zero max_age request parameter? Fixed #994 - Definition of country value within address claim. Fixed #975 - Added additional related specifications. Fixed #996 - Explicitly Ban 307 as the authorization response redirect. Fixed #998 - Reconciled subject_types_supported descriptions. Fixed #999 - Clarified requirements when invalid Redirection URI supplied. Fixed #1002 - Clarified meaning of "exp" claim in the ID Token. Fixed #1005 - Clarify "left truncated SHA-2 hash" in section on symmetric encryption. Fixed #1006 - Clarify text in Third Party Initiated Login. Fixed #1018 - Missing "sub" in examples of aggregated and distributed claims. -24 JWK Thumbprint is now RFC 7638. Allowed signed request objects to be referenced by non-https URLs. -23 Referenced completed RFCs. Added missing URLs in references. Removed compatibility note about Google issuer value. Fixed issue #972 - Nonce requirement in hybrid auth request. Corrected a typo in the spelling of self-issued.me. Changed instances of http://server.example.com to https://server.example.com. Changed to use "Cache-Control: no-cache, no-store" and "Pragma: no-cache" in examples. Tracked terminology changes made in the referenced IETF specs since errata set 1. Updated the RFC 2616 references to RFC 7230, RFC 7231, or RFC 7234, as appropriate. -22 Final specification incorporating errata set 1.