--- title: Authentication requirements description: Configure OpenID Connect authentication requirements and map authentication context class references to authentication journeys in PingAM component: pingam version: 7.5 page_id: pingam:am-oidc1:oidc-authentication-requirements canonical_url: https://docs.pingidentity.com/pingam/8.1/am-oidc1/oidc-authentication-requirements.html llms_txt: https://docs.pingidentity.com/pingam/llms.txt docs_for_agents: https://developer.pingidentity.com/build-with-ai/docs-for-agents.md keywords: ["OpenID Connect (OIDC)", "Standards", "Setup & Configuration", "Authentication"] page_aliases: ["oidc1-guide:oidc-authentication-requirements.adoc"] superseded_by: https://docs.pingidentity.com/pingam/8.1/am-oidc1/oidc-authentication-requirements.html section_ids: acr-claim: The acr claim voluntary_claims: Voluntary claims essential_claims: Essential claims proc-configure-acr: Configure acr claims authn-reqts-request-processing: Request processing amr-claim: The amr claim proc-configure-amr-node: Configure amr claims request-acr-example: Demonstrate authentication requirements auth-reqts-create-rp: Create an RP profile auth-reqts-try-voluntary: Request voluntary claims auth-reqts-try-essential: Request essential claims --- # Authentication requirements A relying party (RP) can have different authentication requirements for different protected resources. For example, a financial services provider accepts username and password authentication to create an account, but requires multi-factor authentication to download bank account statements. PingAM lets you associate requirements with authentication journeys. RPs specify the authentication requirements in their requests, and PingAM uses the associations to authenticate the end user with the requested journey and honor the requirements. PingAM communicates the honored requirements by optionally returning claims in ID tokens. It uses the following standard claims: * An *authentication context class reference* (`acr`) claim holds a case-sensitive string identifying the class of authentication methods or procedures the authentication process satisfied; for example, an identifier for the authentication journey the end user completed successfully. * An *authentication method references* (`amr`) claim holds a JSON array of strings identifying the authentication methods satisfied; for example, an indication the end user has authenticated with a username-password combination and a one-time password. ## The `acr` claim The `acr` claim holds a case-sensitive string you configure in the OAuth 2.0 provider service. PingAM maps `acr` keys to authentication journeys to avoid directly exposing the journey names. PingAM does not add the `acr` claim to ID tokens by default. The RP must request authentication contexts and PingAM must authenticate the end user. The `acr` claims can be *voluntary* or *essential*. ### Voluntary claims RPs request voluntary `acr` claims for optional authentication mechanisms to improve the user experience. They do this in one of the following ways: * Specify the authentication mechanism in the `acr_values` parameter for a request to the `/oauth2/authorize` endpoint. * Specify the authentication mechanisms in the JSON format `claims` parameter for a request to the `/oauth2/authorize` endpoint. * Rather than specifying the mechanisms in the request, rely on Default ACR values in the RP client profile. Find the field in the AM admin UI under Realms > *realm name* > Applications > OAuth 2.0 > *client ID* > OpenID Connect. The default `acr` values are the keys of the mapping set when you [Configure `acr` claims](#proc-configure-acr). The JSON response from the [/oauth2/.well-known/openid-configuration](rest-api-oidc-discovery-configuration.html) endpoint lists the keys as `acr_values_supported` strings; for example: ``` "acr_values_supported": ["username-password"] ``` Any mechanisms the RP specifies in the request override the default `acr` values. ### Essential claims RPs request essential `acr` claims for required authentication mechanisms. RPs request essential `acr` claims by specifying the authentication mechanisms in the JSON format `claims` parameter for a request to the `/oauth2/authorize` endpoint. Essential claims resemble, but are unrelated to, [step-up authentication](../am-sessions/session-upgrade.html). ### Configure `acr` claims 1. In the AM admin UI, go to Realms > *realm name* > Services > OAuth2 Provider > Advanced OpenID Connect. 2. Enable Enable "claims_parameter_supported" to let RPs request `acr` claims using the `claims` parameter. 3. In the OpenID Connect acr_values to Auth Chain Mapping box, map keys to authentication journey identifiers. The following example maps `username-password` to the Login journey: ![Map \`acr\` claim strings to journeys.](_images/oidc-acr-values.png) The key for the journey PingAM use to authenticate the end user becomes the value of the `acr` claim in the resulting ID token. 4. Save your changes. ### Request processing When an RP requests authentication contexts, PingAM initially determines the requested journey. It uses the first context for which it has a valid mapping. For example, if the RP requests `push otp username-password` and PingAM has mappings only for `otp` and `username-password`, PingAM chooses `otp` to authenticate the end user. The following table describes how PingAM processes the request: | Scenario | Voluntary claims result | Essential claims result | | ------------------------------------------------------------------ | ------------------------------------------------------------------------------------------------------------ | ------------------------------------------------------------------------------------------------------------ | | The end user is not authenticated. | Authenticate with the requested journey. | Authenticate with the requested journey. | | The end user is authenticated with the requested journey. | Do not re-authenticate. | Re-authenticate with the requested journey.On success, delete the original session and create a new session. | | The end user is authenticated with a different journey. | Re-authenticate with the requested journey.On success, delete the original session and create a new session. | | | The request specifies an unmapped `acr_values` or `claims` string. | Continue the grant flow without returning an error. | Return an error and redirect to the `redirect_uri`, if available. | After authenticating the end user, PingAM returns an ID token whose `acr` claim has one of the following values: * `0` (zero) The RP requested an unmapped voluntary claim. * `acr-key` The end user authenticated with the journey mapped to *acr-key*. If authentication involves more than one journey, the *acr-key* reflects the last mapped journey. ## The `amr` claim The `amr` claim holds an array of strings identifying families of authentication methods. Because authentication nodes are not used on their own but as part of an authentication journey, you cannot map `amr` values to specific authentication nodes. However, you can map an `AuthType` session property to `amr` values using the [Set Session Properties node](https://docs.pingidentity.com/auth-node-ref/7.5/set-session-properties.html). When the end user authenticates with a journey using the node, AM includes the `amr` claim in the ID token it issues. ### Configure `amr` claims 1. In the AM admin UI, go to Realms > *realm name* > Services > OAuth2 Provider > Advanced OpenID Connect. 2. In the OpenID Connect id_token amr Values to Auth Module Mappings box, map an identifier (the key in the map) to any authentication module. The authentication module you use is not important; AM only uses its name to map the amr, and it won't show in the ID token. > **Collapse: Example: Mapping authentication modules to amr identifiers** > > In this example, we map the identifier to the LDAP authentication module: > > ![oidc-amr-values](_images/oidc-amr-values.png) 3. Save your changes. 4. Go to Realms > *realm name* > Services and add a Session Property Whitelist service. 5. Add `AuthType` to the Allowlisted Session Property Names field. This ensures the property can be read, edited, or deleted, from a session. 6. Save your changes. 7. Create or update [an authentication journey](../am-authentication/about-authentication-trees.html) to include a [Set Session Properties node](https://docs.pingidentity.com/auth-node-ref/7.5/set-session-properties.html). 8. On the Set Session Properties node, configure a key called `AuthType`. As its value, set the name of the authentication module you configured with the amr mapping. For example, `LDAP`. > **Collapse: Example: Configuring the AuthType session property** > > ![amr-set-session-properties](_images/amr-set-session-properties.png) | | | | - | --------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- | | | To reference multiple authentication modules, separate amr values with `\|`. For example, if both the LDAP and the DataStore modules are mapped to amr values, set the `AuthType` key to the value `LDAP\|DataStore`. | 9. Save your changes. ## Demonstrate authentication requirements Demonstrate the process with an RP that uses the [Implicit grant](../am-oauth2/oauth2-implicit-grant.html): 1. Create an end user profile and record the username and password. 2. [Create an RP profile](#auth-reqts-create-rp). 3. Duplicate the default Example journey to create a Login journey. 4. Optionally [Configure `amr` claims](#proc-configure-amr-node). 5. [Configure `acr` claims](#proc-configure-acr) to map your duplicate journey to the `username-password` claim. 6. [Request voluntary claims](#auth-reqts-try-voluntary). 7. [Request essential claims](#auth-reqts-try-essential). ### Create an RP profile [Register an OIDC application](../am-oauth2/oauth2-register-client.html) with the following settings: | | | | ---------------------- | ------------------------------------------ | | Setting | Value | | Name | `myClient` | | Redirection URIs | Add `https://www.example.com:443/callback` | | Scopes | `openid` `profile` | | Advanced > Grant Types | Add `Implicit` | ### Request voluntary claims 1. Open a new tab in your browser. 2. Paste a URL with the `acr_values` parameter to request voluntary claims into the new browser tab: The following URL requests an ID token with the implicit grant: `https://openam.example.com:8443/openam/oauth2/realms/root/realms/alpha/authorize?acr_values=username-password&client_id=myClient&response_type=id_token&scope=openid%20profile&redirect_uri=https://www.example.com:443/callback&nonce=abc123&state=123abc` 3. Authenticate as the end user. PingAM redirects to the application sign-in URL (`redirect_uri`) with the `id_token` in the fragment. 4. Extract the ID token from the sign-in URL. 5. Decode the ID token to display the `acr` claim: ```json { "...": "...", "acr": "username-password" } ``` The `amr` claim is also displayed in the decoded token if you configured `amr` claims, for example: ```json "amr": [ "PWD" ], ``` ### Request essential claims 1. Define and URL-encode the essential claims parameter value. Essential claims requesting `username-password`: ```json {"id_token":{"acr":{"essential":true,"values":["username-password"]}}} ``` URL-encoded value: ``` %7B%22id_token%22%3A%7B%22acr%22%3A%7B%22essential%22%3Atrue%2C%22values%22%3A%5B%22username-password%22%5D%7D%7D%7D ``` 2. Paste a URL with the encoded `claims` parameter to request essential claims into the new browser tab: The following URL requests an ID token with the implicit grant: `https://openam.example.com:8443/openam/oauth2/realms/root/realms/alpha/authorize?claims=%7B%22id_token%22%3A%7B%22acr%22%3A%7B%22essential%22%3Atrue%2C%22values%22%3A%5B%22username-password%22%5D%7D%7D%7D&client_id=myClient&response_type=id_token&scope=openid%20profile&redirect_uri=https://www.example.com:443/callback&nonce=abc123&state=123abc&prompt=login` The `prompt` setting forces the end user to authenticate explicitly regardless of any implied consent. When you request essential claims, PingAM authenticates the end user again. For details, refer to [Request processing](#authn-reqts-request-processing). PingAM redirects to the application sign-in URL (`redirect_uri`) with the `id_token` in the fragment. 3. Extract the ID token from the sign-in URL. 4. Decode the ID token to display the `acr` claim: ```json { "...": "...", "acr": "username-password" } ```