JWKS Rotation - OpenID Connect Authentication

Key rotation is when a key is retired and replaced by generating a new cryptographic key. Rotating keys on a regular basis is an industry standard and follows cryptographic best practices.

You can manually rotate keys periodically to change the JSON web key (JWK) key, or you can configure the appropriate schedule in CAS configuration so it would automatically rotate keys for you.

Rotation Guidance

NIST guidelines seem to recommend a rotation schedule of at least once every two years. In practice, modest CAS deployments in size and scale tend to rotate keys once every six months, either manually or automatically on a schedule.

Keys that are generated by CAS and put into the keystore carry an extra state parameter that indicates the lifecycle status of the assigned key. The following values are accepted lifecycle states:

Value	Description
`0`	The key is active and current, used for required operations.
`1`	The key is will be the next key used during key rotation.
`2`	The key is no longer used and active, and will be removed after revocation operations.

CAS always signs with only one signing key at a time, typically the very first key listed and loaded from the keystore, that is deemed active and current judging by the state parameter. For backward compatibility, the absence of this parameter indicates that the key is active and current.

The dynamic discovery endpoint will always include both the current key and the next key, and it may also include the previous key(s) if the previous key has not yet been revoked. To provide a seamless experience in case of an emergency, client applications should be able to use any of the keys specified in the discovery document.

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

_{The configuration settings listed below are tagged as Required in the CAS configuration metadata. This flag indicates that the presence of the setting may be needed to activate or affect the behavior of the CAS feature and generally should be reviewed, possibly owned and adjusted. If the setting is assigned a default value, you do not need to strictly put the setting in your copy of the configuration, but should review it nonetheless to make sure it matches your deployment expectations.}

_{The configuration settings listed below are tagged as Optional in the CAS configuration metadata. This
flag indicates that the presence of the setting
is not immediately necessary in the end-user CAS configuration, because a default value is assigned or
the activation of the feature is not conditionally controlled by the setting value. You should only include this field in your
configuration if you need to modify the default value.}

cas.authn.oidc.jwks.revocation.schedule.enabled=true

Whether scheduler should be enabled to schedule the job to run.

org.apereo.cas.configuration.model.support.quartz.SchedulingProperties.

_{How can I configure this property?}

Configuration properties can be included and activated using the following strategies.

: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.

CAS properties can be specified using the Java configuration property syntax in any and all .properties files:

cas.authn.oidc.jwks.revocation.schedule.enabled=true

This is the most common form of property configuration that is recognized by CAS, regardless of the actual property source, which might in fact be managed separately outside the CAS environment, by another system or cloud framework.

CAS properties can be specified using the YAML syntax:

cas: 
  authn: 
    oidc: 
      jwks: 
        revocation: 
          schedule: 
            enabled: "true"

Note that YAML is very specific about structure and indentation. Be sure to verify the correctness of the final result with your YAML validator of choice.

CAS properties can be passed to the CAS web application as system properties, when the application is launched:

java -Dcas.authn.oidc.jwks.revocation.schedule.enabled="true" -jar build/libs/cas.war

The above example assumes that the CAS web application is packaged as cas.war with an embedded server container and can be found in the build/libs directory. Note the placement of the system property which must be specified before the CAS web application is launched.

CAS properties can specified as system environment variables before the CAS web application is launched:

export CAS_AUTHN_OIDC_JWKS_REVOCATION_SCHEDULE_ENABLED="true"

java -jar build/libs/cas.war

The above example assumes that the CAS web application is packaged as cas.war with an embedded server container and can be found in the build/libs directory.

CAS properties can be passed to the CAS web application as command-line arguments, when the application is launched:

java -jar build/libs/cas.war --cas.authn.oidc.jwks.revocation.schedule.enabled="true"

The above example assumes that the CAS web application is packaged as cas.war with an embedded server container and can be found in the build/libs directory.

cas.authn.oidc.jwks.revocation.schedule.enabled-on-host=.*

Overrides SchedulingProperties#enabled property value of true if this property does not match hostname of CAS server. This can be useful if deploying CAS with an image in a statefulset where all names are predictable but where having different configurations for different servers is hard. The value can be an exact hostname or a regular expression that will be used to match the hostname.

org.apereo.cas.configuration.model.support.quartz.SchedulingProperties.

_{How can I configure this property?}

Configuration properties can be included and activated using the following strategies.

:information_source: Note

CAS properties can be specified using the Java configuration property syntax in any and all .properties files:

cas.authn.oidc.jwks.revocation.schedule.enabled-on-host=.*

CAS properties can be specified using the YAML syntax:

cas: 
  authn: 
    oidc: 
      jwks: 
        revocation: 
          schedule: 
            enabled-on-host: ".*"

Note that YAML is very specific about structure and indentation. Be sure to verify the correctness of the final result with your YAML validator of choice.

CAS properties can be passed to the CAS web application as system properties, when the application is launched:

java -Dcas.authn.oidc.jwks.revocation.schedule.enabled-on-host=".*" -jar build/libs/cas.war

CAS properties can specified as system environment variables before the CAS web application is launched:

export CAS_AUTHN_OIDC_JWKS_REVOCATION_SCHEDULE_ENABLED_ON_HOST=".*"

java -jar build/libs/cas.war

The above example assumes that the CAS web application is packaged as cas.war with an embedded server container and can be found in the build/libs directory.

CAS properties can be passed to the CAS web application as command-line arguments, when the application is launched:

java -jar build/libs/cas.war --cas.authn.oidc.jwks.revocation.schedule.enabled-on-host=".*"

The above example assumes that the CAS web application is packaged as cas.war with an embedded server container and can be found in the build/libs directory.

cas.authn.oidc.jwks.revocation.schedule.repeat-interval=PT2M

String representation of a repeat interval of re-loading data for an data store implementation. This is the timeout between consecutive job’s executions.

This settings supports the java.time.Duration syntax ^[?].

org.apereo.cas.configuration.model.support.quartz.SchedulingProperties.

_{How can I configure this property?}

Configuration properties can be included and activated using the following strategies.

:information_source: Note

CAS properties can be specified using the Java configuration property syntax in any and all .properties files:

cas.authn.oidc.jwks.revocation.schedule.repeat-interval=PT2M

CAS properties can be specified using the YAML syntax:

cas: 
  authn: 
    oidc: 
      jwks: 
        revocation: 
          schedule: 
            repeat-interval: "PT2M"

Note that YAML is very specific about structure and indentation. Be sure to verify the correctness of the final result with your YAML validator of choice.

CAS properties can be passed to the CAS web application as system properties, when the application is launched:

java -Dcas.authn.oidc.jwks.revocation.schedule.repeat-interval="PT2M" -jar build/libs/cas.war

CAS properties can specified as system environment variables before the CAS web application is launched:

export CAS_AUTHN_OIDC_JWKS_REVOCATION_SCHEDULE_REPEAT_INTERVAL="PT2M"

java -jar build/libs/cas.war

The above example assumes that the CAS web application is packaged as cas.war with an embedded server container and can be found in the build/libs directory.

CAS properties can be passed to the CAS web application as command-line arguments, when the application is launched:

java -jar build/libs/cas.war --cas.authn.oidc.jwks.revocation.schedule.repeat-interval="PT2M"

The above example assumes that the CAS web application is packaged as cas.war with an embedded server container and can be found in the build/libs directory.

cas.authn.oidc.jwks.revocation.schedule.start-delay=PT15S

String representation of a start delay of loading data for a data store implementation. This is the delay between scheduler startup and first job’s execution

This settings supports the java.time.Duration syntax ^[?].

org.apereo.cas.configuration.model.support.quartz.SchedulingProperties.

_{How can I configure this property?}

Configuration properties can be included and activated using the following strategies.

:information_source: Note

CAS properties can be specified using the Java configuration property syntax in any and all .properties files:

cas.authn.oidc.jwks.revocation.schedule.start-delay=PT15S

CAS properties can be specified using the YAML syntax:

cas: 
  authn: 
    oidc: 
      jwks: 
        revocation: 
          schedule: 
            start-delay: "PT15S"

Note that YAML is very specific about structure and indentation. Be sure to verify the correctness of the final result with your YAML validator of choice.

CAS properties can be passed to the CAS web application as system properties, when the application is launched:

java -Dcas.authn.oidc.jwks.revocation.schedule.start-delay="PT15S" -jar build/libs/cas.war

CAS properties can specified as system environment variables before the CAS web application is launched:

export CAS_AUTHN_OIDC_JWKS_REVOCATION_SCHEDULE_START_DELAY="PT15S"

java -jar build/libs/cas.war

The above example assumes that the CAS web application is packaged as cas.war with an embedded server container and can be found in the build/libs directory.

CAS properties can be passed to the CAS web application as command-line arguments, when the application is launched:

java -jar build/libs/cas.war --cas.authn.oidc.jwks.revocation.schedule.start-delay="PT15S"

The above example assumes that the CAS web application is packaged as cas.war with an embedded server container and can be found in the build/libs directory.

cas.authn.oidc.jwks.rotation.schedule.enabled=true

Whether scheduler should be enabled to schedule the job to run.

org.apereo.cas.configuration.model.support.quartz.SchedulingProperties.

_{How can I configure this property?}

Configuration properties can be included and activated using the following strategies.

:information_source: Note

CAS properties can be specified using the Java configuration property syntax in any and all .properties files:

cas.authn.oidc.jwks.rotation.schedule.enabled=true

CAS properties can be specified using the YAML syntax:

cas: 
  authn: 
    oidc: 
      jwks: 
        rotation: 
          schedule: 
            enabled: "true"

Note that YAML is very specific about structure and indentation. Be sure to verify the correctness of the final result with your YAML validator of choice.

CAS properties can be passed to the CAS web application as system properties, when the application is launched:

java -Dcas.authn.oidc.jwks.rotation.schedule.enabled="true" -jar build/libs/cas.war

CAS properties can specified as system environment variables before the CAS web application is launched:

export CAS_AUTHN_OIDC_JWKS_ROTATION_SCHEDULE_ENABLED="true"

java -jar build/libs/cas.war

The above example assumes that the CAS web application is packaged as cas.war with an embedded server container and can be found in the build/libs directory.

CAS properties can be passed to the CAS web application as command-line arguments, when the application is launched:

java -jar build/libs/cas.war --cas.authn.oidc.jwks.rotation.schedule.enabled="true"

The above example assumes that the CAS web application is packaged as cas.war with an embedded server container and can be found in the build/libs directory.

cas.authn.oidc.jwks.rotation.schedule.enabled-on-host=.*

org.apereo.cas.configuration.model.support.quartz.SchedulingProperties.

_{How can I configure this property?}

Configuration properties can be included and activated using the following strategies.

:information_source: Note

CAS properties can be specified using the Java configuration property syntax in any and all .properties files:

cas.authn.oidc.jwks.rotation.schedule.enabled-on-host=.*

CAS properties can be specified using the YAML syntax:

cas: 
  authn: 
    oidc: 
      jwks: 
        rotation: 
          schedule: 
            enabled-on-host: ".*"

Note that YAML is very specific about structure and indentation. Be sure to verify the correctness of the final result with your YAML validator of choice.

CAS properties can be passed to the CAS web application as system properties, when the application is launched:

java -Dcas.authn.oidc.jwks.rotation.schedule.enabled-on-host=".*" -jar build/libs/cas.war

CAS properties can specified as system environment variables before the CAS web application is launched:

export CAS_AUTHN_OIDC_JWKS_ROTATION_SCHEDULE_ENABLED_ON_HOST=".*"

java -jar build/libs/cas.war

The above example assumes that the CAS web application is packaged as cas.war with an embedded server container and can be found in the build/libs directory.

CAS properties can be passed to the CAS web application as command-line arguments, when the application is launched:

java -jar build/libs/cas.war --cas.authn.oidc.jwks.rotation.schedule.enabled-on-host=".*"

The above example assumes that the CAS web application is packaged as cas.war with an embedded server container and can be found in the build/libs directory.

cas.authn.oidc.jwks.rotation.schedule.repeat-interval=PT2M

String representation of a repeat interval of re-loading data for an data store implementation. This is the timeout between consecutive job’s executions.

This settings supports the java.time.Duration syntax ^[?].

org.apereo.cas.configuration.model.support.quartz.SchedulingProperties.

_{How can I configure this property?}

Configuration properties can be included and activated using the following strategies.

:information_source: Note

CAS properties can be specified using the Java configuration property syntax in any and all .properties files:

cas.authn.oidc.jwks.rotation.schedule.repeat-interval=PT2M

CAS properties can be specified using the YAML syntax:

cas: 
  authn: 
    oidc: 
      jwks: 
        rotation: 
          schedule: 
            repeat-interval: "PT2M"

Note that YAML is very specific about structure and indentation. Be sure to verify the correctness of the final result with your YAML validator of choice.

CAS properties can be passed to the CAS web application as system properties, when the application is launched:

java -Dcas.authn.oidc.jwks.rotation.schedule.repeat-interval="PT2M" -jar build/libs/cas.war

CAS properties can specified as system environment variables before the CAS web application is launched:

export CAS_AUTHN_OIDC_JWKS_ROTATION_SCHEDULE_REPEAT_INTERVAL="PT2M"

java -jar build/libs/cas.war

The above example assumes that the CAS web application is packaged as cas.war with an embedded server container and can be found in the build/libs directory.

CAS properties can be passed to the CAS web application as command-line arguments, when the application is launched:

java -jar build/libs/cas.war --cas.authn.oidc.jwks.rotation.schedule.repeat-interval="PT2M"

The above example assumes that the CAS web application is packaged as cas.war with an embedded server container and can be found in the build/libs directory.

cas.authn.oidc.jwks.rotation.schedule.start-delay=PT15S

String representation of a start delay of loading data for a data store implementation. This is the delay between scheduler startup and first job’s execution

This settings supports the java.time.Duration syntax ^[?].

org.apereo.cas.configuration.model.support.quartz.SchedulingProperties.

_{How can I configure this property?}

Configuration properties can be included and activated using the following strategies.

:information_source: Note

CAS properties can be specified using the Java configuration property syntax in any and all .properties files:

cas.authn.oidc.jwks.rotation.schedule.start-delay=PT15S

CAS properties can be specified using the YAML syntax:

cas: 
  authn: 
    oidc: 
      jwks: 
        rotation: 
          schedule: 
            start-delay: "PT15S"

Note that YAML is very specific about structure and indentation. Be sure to verify the correctness of the final result with your YAML validator of choice.

CAS properties can be passed to the CAS web application as system properties, when the application is launched:

java -Dcas.authn.oidc.jwks.rotation.schedule.start-delay="PT15S" -jar build/libs/cas.war

CAS properties can specified as system environment variables before the CAS web application is launched:

export CAS_AUTHN_OIDC_JWKS_ROTATION_SCHEDULE_START_DELAY="PT15S"

java -jar build/libs/cas.war

The above example assumes that the CAS web application is packaged as cas.war with an embedded server container and can be found in the build/libs directory.

CAS properties can be passed to the CAS web application as command-line arguments, when the application is launched:

java -jar build/libs/cas.war --cas.authn.oidc.jwks.rotation.schedule.start-delay="PT15S"

The above example assumes that the CAS web application is packaged as cas.war with an embedded server container and can be found in the build/libs directory.

# Whether scheduler should be enabled to schedule the job to run.
# cas.authn.oidc.jwks.revocation.schedule.enabled=true

# Overrides {@link SchedulingProperties#enabled} property value of true if this property does not match hostname of CAS server.
# cas.authn.oidc.jwks.revocation.schedule.enabled-on-host=.*

# String representation of a repeat interval of re-loading data for an data store implementation.
# cas.authn.oidc.jwks.revocation.schedule.repeat-interval=PT2M

# String representation of a start delay of loading data for a data store implementation.
# cas.authn.oidc.jwks.revocation.schedule.start-delay=PT15S

# Whether scheduler should be enabled to schedule the job to run.
# cas.authn.oidc.jwks.rotation.schedule.enabled=true

# Overrides {@link SchedulingProperties#enabled} property value of true if this property does not match hostname of CAS server.
# cas.authn.oidc.jwks.rotation.schedule.enabled-on-host=.*

# String representation of a repeat interval of re-loading data for an data store implementation.
# cas.authn.oidc.jwks.rotation.schedule.repeat-interval=PT2M

# String representation of a start delay of loading data for a data store implementation.
# cas.authn.oidc.jwks.rotation.schedule.start-delay=PT15S

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.

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, specially if defined CAS settings cannot be recognized or validated by the configuration schema. The validation process is on by default and can be skipped on startup using a special system property SKIP_CONFIG_VALIDATION that should be set to true. 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.

Custom

It is possible to design and inject your own key rotation and revocation strategy into CAS using the following @Bean that would be registered in a @AutoConfiguration class:

@Bean
public OidcJsonWebKeystoreRotationService oidcJsonWebKeystoreRotationService() {
    return new MyJsonWebKeystoreRotationService();
}

Your configuration class needs to be registered with CAS. See this guide for better details.