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 with additional support to map principal attributes into the appropriate claims and properties of the user resource.
SCIM v2 is supported, thanks to the SDK provided by UnboundID.
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:
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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:${project.'cas.version'}"
}
}
dependencies {
implementation "org.apereo.cas:cas-server-support-scim"
}
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dependencies {
/*
The following platform references should be included automatically and are listed here for reference only.
implementation enforcedPlatform("org.apereo.cas:cas-server-support-bom:${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-token=
Authenticate into the SCIM server/service via a pre-generated OAuth token.
|
cas.scim.password=
Authenticate into the SCIM server with a pre-defined password.
|
cas.scim.target=
The SCIM provisioning target URI.
|
cas.scim.username=
Authenticate into the SCIM server with a pre-defined username.
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cas.scim.enabled=true
Decide whether scim should be enabled.
|
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.
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, specially 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 . |
email |
Set to the principal attribute email . |
phoneNumber |
Set to the principal attribute phoneNumber . |
externalId |
Set to the principal attribute externalId . |
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 ScimV2PrincipalAttributeMapper scim2PrincipalAttributeMapper() {
return new MyPrincipalAttributeMapper();
}
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" ] ]
}
}
}