APEREO CASDocumentation

Enterprise Authentication for All Earthlings and Beyond

Identity, Single Sign-On and Access Management
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SCIM Principal Provisioning

The SCIM standard is created to simplify user management and provisioning in the cloud by defining a schema for representing users and groups and a REST API for all the necessary CRUD operations. SCIM integrations with CAS allow deployers to auto-provision the authenticated CAS principal to a SCIM server/target that supports the v2 specification of the SCIM protocol with additional support to map principal attributes into the appropriate claims and properties of the user resource.

Typical use case for enabling SCIM is to synchronize and provision user accounts, just in time, to services and applications that are integrated with CAS for single sign-on. In cases where the application also has its own account store, a mapping of user accounts between the CAS canonical account store (LDAP, JDBC, etc) and the application may be required. To accommodate this issue, CAS may be allowed to provision the authenticated principal via SCIM to a provisioning/identity/entity engine which would then dynamically synchronize user profiles to target systems.

Configuration

Support is enabled by including the following dependency 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-scim</artifactId>
    <version>${cas.version}</version>
</dependency>





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implementation "org.apereo.cas:cas-server-support-scim:${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-scim"
}





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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-scim"
}

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

cas.scim.oauth-tokenAuthenticate into the SCIM server/service via a pre-generated OAuth token.
no default
Required

Authenticate into the SCIM server/service via a pre-generated OAuth token.

Type
String
Default
none
Defined by
ScimProvisioningProperties
cas.scim.passwordAuthenticate into the SCIM server with a pre-defined password.
no default
Required

Authenticate into the SCIM server with a pre-defined password.

Type
String
Default
none
Defined by
ScimProvisioningProperties
cas.scim.schema-mappingsMap of attributes that define how SCIM schema attributes should be populated using CAS attributes.
no default
Required

Map of attributes that define how SCIM schema attributes should be populated using CAS attributes. The key is the SCIM schema attribute name and the value is the CAS attribute name. If the CAS attribute is not found, the SCIM attribute is typically ignored.

Type
Map<String,String>
Default
none
Defined by
ScimProvisioningProperties
cas.scim.targetThe SCIM provisioning target URI.
no default
Required

The SCIM provisioning target URI.

Type
String
Default
none
Defined by
ScimProvisioningProperties
cas.scim.usernameAuthenticate into the SCIM server with a pre-defined username.
no default
Required

Authenticate into the SCIM server with a pre-defined username.

Type
String
Default
none
Defined by
ScimProvisioningProperties
cas.scim.asynchronousIndicate whether provisioning should be asynchronous.
false

Indicate whether provisioning should be asynchronous.

Type
Boolean
Default
false
Defined by
ScimProvisioningProperties
cas.scim.enabledDecide whether scim should be enabled.
true

Decide whether scim should be enabled.

Type
Boolean
Default
true
Defined by
ScimProvisioningProperties

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.

Mapping Attributes

SCIM user resources are populated from CAS authenticated principals using one-to-one mapping rules. For example, the givenName attribute in the SCIM schema is mapped and populated from the givenName attributes found for the CAS principal.

The set of attributes that are mapped are as follows:

Attribute Description
userName Set to the principal id.
password Set to the credential password, if available.
nickName Set to the principal attribute nickName.
displayName Set to the principal attribute displayName.
givenName Set to the principal attribute givenName.
familyName Set to the principal attribute familyName.
middleName Set to the principal attribute middleName.
email Set to the principal attribute email.
phoneNumber Set to the principal attribute phoneNumber.
externalId Set to the principal attribute externalId.
entitlements Set to the principal attribute entitlements.
roles Set to the principal attribute roles.
addresses Set to the principal attribute addresses.
ims Set to the principal attribute ims.
employeeNumber Set to the principal attribute employeeNumber.
costCenter Set to the principal attribute costCenter.
division Set to the principal attribute division.
department Set to the principal attribute department.
organization Set to the principal attribute organization.
resourceType Set to the principal attribute resourceType.
groups Set to the principal attribute groups.

The default mapping rules can be controlled and customized using CAS properties.

If the default mapping rules are not suitable, the mapping rules can always be adjusted and customized using the following bean:



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@Bean
public ScimPrincipalAttributeMapper scim2PrincipalAttributeMapper() {
    return new MyPrincipalAttributeMapper();
}

Mapping Groups

CAS can also provision groups to SCIM targets. The groups are populated from the principal attribute groups. Memberships can be dynamically created, updated or removed based on the principal’s group memberships.

Per Application

SCIM relevant settings can be specified per application in form of service properties.

The following properties are available and recognized by CAS for various modules and features:

Name Default Value Type Group
scimOAuthToken STRING SCIM
scimUsername STRING SCIM
scimPassword STRING SCIM
scimTarget STRING SCIM

A sample JSON file follows:



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{
  "@class" : "org.apereo.cas.services.CasRegisteredService",
  "serviceId" : "^https://.+",
  "name" : "sample service",
  "id" : 1,
  "properties" : {
    "@class" : "java.util.HashMap",
    "scimUsername" : {
      "@class" : "org.apereo.cas.services.DefaultRegisteredServiceProperty",
      "values" : [ "java.util.HashSet", [ "username" ] ]
    },
    "scimPassword" : {
      "@class" : "org.apereo.cas.services.DefaultRegisteredServiceProperty",
      "values" : [ "java.util.HashSet", [ "p@$$w0rd" ] ]
    }
  }
}