--- title: Token exchange description: Advanced Identity Cloud supports RFC 8693, OAuth 2.0 Token Exchange for OAuth 2.0 and OpenID Connect tokens: component: pingoneaic page_id: pingoneaic:am-oauth2:token-exchange canonical_url: https://docs.pingidentity.com/pingoneaic/am-oauth2/token-exchange.html keywords: ["OAuth 2.0", "OpenID Connect (OIDC)", "Authorization", "Endpoints", "Grant Flow", "Setup & Configuration"] page_aliases: ["oauth2-guide:token-exchange-configuration.adoc", "oauth2-guide:token-exchange-flows.adoc", "oauth2-guide:scripting-api-may_act.adoc", "oauth2-guide:token-exchange.adoc"] section_ids: use_cases: Use cases token-exchange-impersonation: Impersonation example_with_an_access_token: Example with an access token example_with_an_id_token: Example with an ID token token-exchange-delegation: Delegation example_with_an_actor_access_token: Example with an actor access token example_with_an_actor_id_token: Example with an actor ID token terminology: Terminology configuration: Configuration token-exchange-authorization: Authorize exchange the_may_act_claim: The may_act claim may_act_scripts: May act scripts oauth_2_0_provider_settings: OAuth 2.0 provider settings client_settings: Client settings request_parameters: Request parameters --- # Token exchange Advanced Identity Cloud supports RFC 8693, [OAuth 2.0 Token Exchange](https://www.rfc-editor.org/info/rfc8693) for OAuth 2.0 and OpenID Connect tokens: **Supported OAuth 2.0 token exchange** | From/to | Access token | ID token | Refresh tokens1 | SAML assertion | | ------------ | --------------------- | --------------------- | --------------------- | --------------------- | | Access token | [icon: check, set=fa] | [icon: check, set=fa] | [icon: times, set=fa] | [icon: times, set=fa] | | ID token | [icon: check, set=fa] | [icon: check, set=fa] | [icon: times, set=fa] | [icon: times, set=fa] | 1 You can't exchange a token directly for a refresh token. When Advanced Identity Cloud issues [refresh tokens](oauth2-refresh-tokens.html) (default), it also issues them on token exchange. | | | | - | -------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- | | | Clients can exchange tokens only at the OAuth 2.0 provider that issued them.This restriction applies to Advanced Identity Cloud domains *and to realms*. For example, a token issued by `https:///am/oauth2/realms/root/realms/alpha` can't be exchanged at `https:///am/oauth2/realms/root/realms/bravo`. | Differences with normal token issuance: * Advanced Identity Cloud copies claims and values that must not change, such as subject and issuer claims, from the *subject token* to the new token. Advanced Identity Cloud ignores irrelevant claims, such as those missing from the resulting token type, and claims that cannot be inferred from the subject token, such as those present in the resulting token, but not in the subject token. * Advanced Identity Cloud does not copy scopes, but derives them from the scope implementation. For details, refer to [Scopes](oauth2-scopes.html). * Advanced Identity Cloud adds the `act` and `may_act` claims when relevant. * Token exchange involves *no end user interaction*. There is no way to request consent for expanded scopes or claims. The client application must ensure end user consent beforehand or must ensure an expanded scope or claim is unrelated to the end user's resources. ## Use cases OAuth2.0 clients exchange tokens for *impersonation* or *delegation*. ### Impersonation To impersonate means to pretend you are someone else when performing a job or duty. Use impersonation for token exchange when it is not necessary to maintain separation between the end user and the client. The client obtains a *subject token* with the end user's authorization. It exchanges this token for a new token it can use directly to access a protected resource. *Due to the risk of identity theft, allow token impersonation across trusted systems only.* | | | | - | ------------------------------------------------------------------------------------------------------------------ | | | To try token exchange with impersonation, refer to [Demonstrate impersonation](token-exchange-impersonation.html). | #### Example with an access token An end user chooses to transfer money using their bank application, an OAuth 2.0 client. The end user authenticates to the application and trusts the application to act on their behalf when accessing the internal banking system to perform transactions. When the end user authenticates, the application gets an access token with `change_data`, `create_accounts`, `read_accounts`, and `transfer` scopes. The scopes represent all banking services available through the application. The end user chooses to transfer money, which requires only the `transfer` scope. To reduce the security risk, the application exchanges the broad-scope access token for a restricted access token with only the `transfer` scope, which it uses to access the transfer service: ![OAuth 2.0 token exchange with impersonation based on an access token](_images/oauth2-token-exchange-1.svg) #### Example with an ID token The client could request an ID token instead of an access token. When the end user authenticates, the application gets an ID token as the subject token. The ID token attests to the user's identity and authorization, but does not include scopes to access banking services. The end user chooses to transfer money, and the application exchanges the ID token for an expanded access token with the `transfer` scope, which it uses to access the transfer service: ![OAuth 2.0 token exchange with impersonation based on an ID token](_images/oauth2-token-exchange-2.svg) ### Delegation To delegate means to give a job or duty to someone else who performs the job on your behalf. Use delegation for token exchange when maintaining separation between the end user and the client is important. This approach is more secure when the token must traverse third-party systems. | | | | - | --------------------------------------------------------------------------------------------------------- | | | To try token exchange with delegation, refer to [Demonstrate delegation](token-exchange-delegation.html). | In delegation, the client has two tokens: * A subject token obtained with the end user's authorization. * An *actor token* obtained for itself or the end user it represents. The client exchanges both tokens for a new token it can use to access the protected resource. The new token has an `act` (actor) claim. The `act` claim, visible on [introspection](oauth2-introspect-endpoint.html), signals to the resource server that the client using the token is *not* the end user. A resource server can adapt its behavior as necessary. The following example shows the `act` claim field of an access token: ```none "act": { "sub": "delegateClient" } ``` The `sub` field specifies the subject of the actor token. #### Example with an actor access token An end user phones a call center about a problem with their water supply. The operator who responds verifies the user's identity and creates an ID token as the subject token. The operator also creates an access token as the *actor token* for themselves. The operator exchanges both tokens for an access token with the `repair` scope restricted to booking a repair. The operator would need a different token to end the user's contract, for example. When they book a repair for the user, both the operator and the end user are reflected in the repair request: ![OAuth 2.0 token exchange with delegation based on an actor access token](_images/oauth2-token-exchange-3.svg) #### Example with an actor ID token The operator could request an actor ID token instead of an access token: ![OAuth 2.0 token exchange with delegation based on an actor ID token](_images/oauth2-token-exchange-4.svg) ## Terminology * Act claim Token claim identifying a delegate acting on behalf of another identity. Advanced Identity Cloud automatically adds this claim as needed when issuing a token. * Actor token The access or ID token representing a delegate acting on behalf of another identity. * Exchanged token The new access or ID token resulting from token exchange. Exchanged tokens do not expire at the same time as their subject tokens. They expire after the amount of time specified in the Access Token Lifetime (seconds) or the OpenID Connect JWT Token Lifetime (seconds) settings of the OAuth 2.0 provider service or client configuration. * Expanded token An access token with scopes or claims not present in the subject token. An exchanged token can have different scopes and claims from the subject token. Expanded tokens work well when exchanging ID tokens for access tokens, for example, where scopes and claims differ. * May act claim Token claim specifying who is allowed to act for the identity on behalf of whom the request is made. Only the identity specified in the `may_act` claim can exchange tokens for another token. You must write a script to add this claim as needed when issuing a token. For details, refer to [Authorize exchange](#token-exchange-authorization). * Restricted token An access token with narrower scopes or claims than those of the subject token. Instead of gathering consent for different sets of scopes and claims, clients gather consent for a broad range initially and then restrict scope during token exchange. * Subject token The access or ID token representing the identity on behalf of whom the request is made. The client can obtain the subject token with any supported OAuth 2.0 or OpenID Connect flow. ## Configuration Token exchange configuration requires: * A script to authorize exchange. * Settings in the OAuth 2.0 provider or the OAuth 2.0 client application configuration. ### Authorize exchange A claim on the original token authorizes specified clients and actors to perform the exchange. You write a script Advanced Identity Cloud runs when issuing tokens to set the claim. #### The `may_act` claim The `may_act` claim on a token identifies the authorized actor who can exchange the token. Advanced Identity Cloud sets this claim when issuing the original token. * For impersonation, the `may_act` claim must specify the client ID of the authorized actor. * For delegation, the `may_act` claim must specify the client ID and the `sub` (subject) of the actor token. Advanced Identity Cloud rejects token exchange requests from clients or actors who are not authorized by the `may_act` claim. The following example claim allows: * An `impersonationClient` to exchange the token and impersonate the end user. * A `delegateClient` to exchange the token to act on the end user's behalf using the original token and an actor token issued directly to the client with the client credentials grant. ```none "may_act": { // String or array of client IDs who can exchange the token: "client_id": ["impersonationClient", "delegateClient"], // String or array identifying the actor token subject(s) for delegation: "sub": "delegateClient" } ``` #### May act scripts Advanced Identity Cloud has no default functionality to authorize token exchange for specific clients. Instead, create an `OAuth2 May Act` script for Advanced Identity Cloud to run when issuing a token. Use the Advanced Identity Cloud admin console to create a legacy script or use the native AM console to create a next-generation script. Under Native Consoles > Access Management, go to Scripts > + New Script, and select Next Generation as the evaluator version. The following example JavaScript produces the previous example claim without the comments: * Legacy * Next-generation ```javascript (function () { var frJava = JavaImporter( org.forgerock.json.JsonValue ); var mayAct = frJava.JsonValue.json(frJava.JsonValue.object()) mayAct.put('client_id', ['impersonationClient', 'delegateClient']) mayAct.put('sub', 'delegateClient') token.setMayAct(mayAct) }()); ``` ```javascript (function () { var mayAct = { 'client_id': ['impersonationClient', 'delegateClient'], 'sub': 'delegateClient' }; token.setMayAct(mayAct); }()); ``` Find a commented example in the [sample legacy may act script](../_attachments/scripts/oauth2-may-act.js). Advanced Identity Cloud doesn't support wildcards in the `client_id` and `sub` fields. Your scripts must enumerate clients and actors. The script doesn't specify the token type. The client requesting an exchange token optionally specifies the token type. Learn about the next-generation and legacy may act script bindings in [the API](../am-scripting/may-act-api.html). ### OAuth 2.0 provider settings The OAuth 2.0 provider settings govern token exchange behavior for all clients in the realm. To access these settings, go to Native Consoles > Access Management > Realms > *Realm Name* > Services > OAuth2 Provider. The relevant settings are: * Core tab * OAuth2 Access Token May Act Script: Use the selected script to set the `may_act` claim on all access tokens. * OIDC ID Token May Act Script: Use the selected script to set the `may_act` claim on all ID tokens. Choose `--- Select a script ---` to prevent Advanced Identity Cloud from setting the claim. * Advanced tab * Grant Types: Add the `Token Exchange` type to permit token exchange requests. * Token Exchanger Plugins: Remove any token exchange combinations you do not want to allow. * Token Validator Plugins: If necessary, remove validations that tokens meet the criteria for exchange. ### Client settings Individual OAuth 2.0 client settings govern [authentication levels](../am-authentication/auth-nodes-and-journeys.html#authentication-levels-trees) granted to exchanged tokens and can override OAuth 2.0 provider settings. To access these settings, go to Native Consoles > Access Management > Realms > *Realm Name* > Applications > OAuth 2.0 > Clients > *Client ID*. The relevant settings are: * Advanced tab * Token Exchange Auth Level: The authentication level granted to exchanged tokens when the subject token had no `auth_level` claim. This setting always applies to exchanged ID tokens. * Grant Types: Add the `Token Exchange` type to permit token exchange requests. * OAuth2 Provider Overrides tab * Enable OAuth2 Provider Overrides: Use these settings instead of those on the OAuth2 Provider service. * OAuth2 Access Token May Act Script: Use the selected script to set the `may_act` claim on access tokens. * OIDC ID Token May Act Script: Use the selected script to set the `may_act` claim on ID tokens. For the may act script settings, choose `--- Select a script ---` to prevent Advanced Identity Cloud from setting the claim. ## Request parameters Token exchange requests target the [/oauth2/access\_token](oauth2-access_token-endpoint.html) endpoint. The requests use the following specific parameters: | Parameter | Description | | ---------------------- | -------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- | | `grant_type` | Required.Use `grant_type=urn:ietf:params:oauth:grant-type:token-exchange`. | | `subject_token` | Required.The original token to exchange.Example: `subject_token=RzOn3NbDyebd5hFVvzVrE2kox1A-lQ` | | `subject_token_type` | Required.The type of subject token, either access token or ID token. One of:- `subject_token_type=urn:ietf:params:oauth:token-type:access_token` - `subject_token_type=urn:ietf:params:oauth:token-type:id_token` | | `actor_token` | Required for delegation.The token representing the delegate.Example: `actor_token=wNv5kr5QaugeY2IqptR3Zg7AEvg` | | `actor_token_type` | Required for delegation.The type of actor token, either access token or ID token. One of:- `actor_token_type=urn:ietf:params:oauth:token-type:access_token` - `actor_token_type=urn:ietf:params:oauth:token-type:id_token` | | `requested_token_type` | Optional.The type of requested exchanged token, either access token or ID token. One of:- `requested_token_type=urn:ietf:params:oauth:token-type:access_token` (default) - `requested_token_type=urn:ietf:params:oauth:token-type:id_token` |