APEREO CASDocumentation

Enterprise Authentication for All Earthlings and Beyond

Identity, Single Sign-On and Access Management
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JWKS - OpenID Connect Authentication

The JWKS (JSON Web Key Set) endpoint and functionality returns a JWKS containing public keys that enable clients to validate a JSON Web Token (JWT) issued by CAS as an OpenID Connect Provider.

The following settings and properties are available from the CAS configuration catalog:

cas.authn.oidc.jwks.core.jwks-cache-expirationTimeout that indicates how long should the JWKS file be kept in cache.
PT60M
Duration

Timeout that indicates how long should the JWKS file be kept in cache.

Type
String
Default
PT60M
Defined by
OidcJsonWebKeystoreCoreProperties
cas.authn.oidc.jwks.core.jwks-key-idThe key identifier to set for the generated key in the keystore.
cas

The key identifier to set for the generated key in the keystore.

Type
String
Default
cas
Defined by
OidcJsonWebKeystoreCoreProperties
cas.authn.oidc.jwks.core.jwks-key-sizeThe key size for the generated jwks.
2048

The key size for the generated jwks. This is an algorithm-specific metric, such as modulus length, specified in number of bits.

If the keystore type is EC, the key size defined here should switch to one of 256, 384 or 521. If using EC, then the size should match the number of bits required.

Type
Integer
Default
2048
Defined by
OidcJsonWebKeystoreCoreProperties
cas.authn.oidc.jwks.core.jwks-typeThe type of the JWKS used to handle signing/encryption of authentication tokens.
RSA

The type of the JWKS used to handle signing/encryption of authentication tokens. Accepted values are RSA or EC.

Type
String
Default
RSA
Defined by
OidcJsonWebKeystoreCoreProperties

Required settings may be needed to activate or affect the feature; review them even when they have a default. Optional settings only need to be set to change a default or to turn on the behavior they control. Third party settings belong to libraries such as Spring Boot that CAS builds on; their own documentation may have more detail.

Notes on configuration

Configuration Metadata

The collection of configuration properties listed in this section are automatically generated from the CAS source and components that contain the actual field definitions, types, descriptions, modules, etc. This metadata may not always be 100% accurate, or could be lacking details and sufficient explanations.

Be Selective

This section is meant as a guide only. Do NOT copy/paste the entire collection of settings into your CAS configuration; rather pick only the properties that you need. Do NOT enable settings unless you are certain of their purpose and do NOT copy settings into your configuration only to keep them as reference. All these ideas lead to upgrade headaches, maintenance nightmares and premature aging.

YAGNI

Note that for nearly ALL use cases, declaring and configuring properties listed here is sufficient. You should NOT have to explicitly massage a CAS XML/Java/etc configuration file to design an authentication handler, create attribute release policies, etc. CAS at runtime will auto-configure all required changes for you. If you are unsure about the meaning of a given CAS setting, do NOT turn it on without hesitation. Review the codebase or better yet, ask questions to clarify the intended behavior.

Naming Convention

Property names can be specified in very relaxed terms. For instance cas.someProperty, cas.some-property, cas.some_property are all valid names. While all forms are accepted by CAS, there are certain components (in CAS and other frameworks used) whose activation at runtime is conditional on a property value, where this property is required to have been specified in CAS configuration using kebab case. This is both true for properties that are owned by CAS as well as those that might be presented to the system via an external library or framework such as Spring Boot, etc.

:information_source: Note

When possible, properties should be stored in lower-case kebab format, such as cas.property-name=value. The only possible exception to this rule is when naming actuator endpoints; The name of the actuator endpoints (i.e. ssoSessions) MUST remain in camelCase mode.

Settings and properties that are controlled by the CAS platform directly always begin with the prefix cas. All other settings are controlled and provided to CAS via other underlying frameworks and may have their own schemas and syntax. BE CAREFUL with the distinction. Unrecognized properties are rejected by CAS and/or frameworks upon which CAS depends. This means if you somehow misspell a property definition or fail to adhere to the dot-notation syntax and such, your setting is entirely refused by CAS and likely the feature it controls will never be activated in the way you intend.

Validation

Configuration properties are automatically validated on CAS startup to report issues with configuration binding, especially if defined CAS settings cannot be recognized or validated by the configuration schema. Additional validation processes are also handled via Configuration Metadata and property migrations applied automatically on startup by Spring Boot and family.

Indexed Settings

CAS settings able to accept multiple values are typically documented with an index, such as cas.some.setting[0]=value. The index [0] is meant to be incremented by the adopter to allow for distinct multiple configuration blocks.

Keystore Storage

Please see this guide for more info.

Key Rotation

Please see this guide for more info.

Actuator Endpoints

The following endpoints are provided by CAS:

oidcJwks
CAS endpoint4 operationsNot exposed by defaultcas-server-support-oidc
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Include the module that provides this endpoint in the WAR overlay:

Show in CAS Initializr Generate CAS Server WAR Overlay 


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<dependency>
    <groupId>org.apereo.cas</groupId>
    <artifactId>cas-server-support-oidc</artifactId>
    <version>${cas.version}</version>
</dependency>





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implementation "org.apereo.cas:cas-server-support-oidc:${project.'cas.version'}"





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dependencyManagement {
    imports {
        mavenBom "org.apereo.cas:cas-server-support-bom:${project.'cas.version'}"
    }
}

dependencies {
    implementation "org.apereo.cas:cas-server-support-oidc"
}





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dependencies {
    /*
        The following platform references are included automatically and are listed for reference only.

        implementation enforcedPlatform("org.apereo.cas:cas-server-support-bom:${project.'cas.version'}")
        implementation platform(org.springframework.boot.gradle.plugin.SpringBootPlugin.BOM_COORDINATES)
        
    */
    implementation "org.apereo.cas:cas-server-support-oidc"
}
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Turn the endpoint on and expose it over the web. One entry covers every operation. By default only info, health and status are exposed.



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management.endpoint.oidcJwks.access=UNRESTRICTED
management.endpoints.web.exposure.include=oidcJwks

Endpoints may be mapped to other paths. For example, to serve health at healthcheck:



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management.endpoints.web.path-mapping.health=healthcheck