SAML2 Attribute Release

Attribute filtering and release policies are defined per SAML service. See this guide for more info.

Attribute Definitions

Attribute definitions that specifically apply to the release of attributes as part of SAML response can be defined using the SamlIdPAttributeDefinition. Defining an attribute with this definition does not prevent it from being released by other protocols.

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{
  "@class": "java.util.TreeMap",
  "eduPersonPrincipalName": {
    "@class": "org.apereo.cas.support.saml.web.idp.profile.builders.attr.SamlIdPAttributeDefinition",
    "key": "eduPersonPrincipalName",
    "name": "eduPersonPrincipalName",
    "urn": "urn:oid:1.3.6.1.4.1.5923.1.1.1.6",
    "scoped": true,
    "encrypted": false,
    "attribute": "uid",
    "friendlyName": "eduPersonPrincipalName"
  }
}

The following additional settings can be specified for a Saml IdP attribute definition:

Name Description
friendlyName (Optional) Friendly name of the attribute shared with the target application during attribute release.
urn (Optional) Defined Universal Resource name for an attribute (i.e. urn:oid:1.3.6.1.4.1.5923.1.1.1.6).

To learn more about attribute definitions, please see this guide.

Attribute Value Types

By default, attribute value blocks that are created in the final SAML2 response do not carry any type information in the encoded XML. You can, if necessary, enforce a particular type for an attribute value per the requirements of the SAML2 service provider, if any. An example of an attribute that is encoded with specific type information would be:

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<saml2:Attribute FriendlyName="givenName" Name="givenName" NameFormat="urn:oasis:names:tc:SAML:2.0:attrname-format:uri">
    <saml2:AttributeValue xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:type="xsd:string">HelloWorld</saml2:AttributeValue>
</saml2:Attribute>

The following attribute value types are supported:

Type Description
XSString Mark the attribute value type as string.
XSURI Mark the attribute value type as uri.
XSBoolean Mark the attribute value type as boolean.
XSInteger Mark the attribute value type as integer.
XSDateTime Mark the attribute value type as datetime .
XSBase64Binary Mark the attribute value type as base64Binary.
XSObject Skip the attribute value type and serialize the value as a complex XML object/POJO.

…where the types for each attribute would be defined as such:

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{
  "@class": "org.apereo.cas.support.saml.services.SamlRegisteredService",
  "serviceId" : "the-entity-id-of-the-sp",
  "name": "SAML Service",
  "metadataLocation" : "../../sp-metadata.xml",
  "id": 1,
  "attributeValueTypes": {
    "@class": "java.util.HashMap",
    "<attribute-name>": "<attribute-value-type>"
  }
}

Attribute Name Formats

Attribute name formats can be specified per relying party in the service registry.

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{
  "@class": "org.apereo.cas.support.saml.services.SamlRegisteredService",
  "serviceId" : "the-entity-id-of-the-sp",
  "name": "SAML Service",
  "metadataLocation" : "../../sp-metadata.xml",
  "id": 100001,
  "attributeNameFormats": {
    "@class": "java.util.HashMap",
    "attributeName": "basic|uri|unspecified|custom-format-etc"
  }
}

Name formats for an individual attribute can be mapped to a number of pre-defined formats, or a custom format of your own choosing. A given attribute that is to be encoded in the final SAML response may contain any of the following name formats:

Type Description
basic Map the attribute to urn:oasis:names:tc:SAML:2.0:attrname-format:basic.
uri Map the attribute to urn:oasis:names:tc:SAML:2.0:attrname-format:uri.
unspecified Map the attribute to urn:oasis:names:tc:SAML:2.0:attrname-format:basic.
urn:my:own:format Map the attribute to urn:my:own:format.

You may also have the option to define attributes and their relevant name format globally via CAS properties.

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.

  • cas.authn.saml-idp.core.entity-id=https://cas.example.org/idp
  • The SAML entity id for the deployment.

    This setting supports the Spring Expression Language.

    This setting is owned by org.apereo.cas.configuration.model.support.saml.idp.SamlIdPCoreProperties.

    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.

  • cas.authn.saml-idp.core.attribute-friendly-names=
  • A mapping of attribute names to their friendly names, defined globally. Example might be urn:oid:1.3.6.1.4.1.5923.1.1.1.6->eduPersonPrincipalName.

    This setting is owned by org.apereo.cas.configuration.model.support.saml.idp.SamlIdPCoreProperties.

  • cas.authn.saml-idp.core.attribute-query-profile-enabled=false
  • Indicates whether attribute query profile is enabled. Enabling this setting would allow CAS to record SAML responses and have them be made available later for attribute lookups.

    This setting is owned by org.apereo.cas.configuration.model.support.saml.idp.SamlIdPCoreProperties.

  • cas.authn.saml-idp.core.authentication-context-class-mappings=
  • A mapping of authentication context class refs. This is where specific authentication context classes are reference and mapped to providers that CAS may support mainly for MFA purposes.

    Example might be urn:oasis:names:tc:SAML:2.0:ac:classes:SomeClassName->mfa-duo.

    This setting is owned by org.apereo.cas.configuration.model.support.saml.idp.SamlIdPCoreProperties.

  • cas.authn.saml-idp.core.session-storage-type=https://cas.example.org/idp
  • Indicates whether saml requests, and other session data, collected as part of SAML flows and requests that are kept by the container http session, local storage, or should be replicated across the cluster. Available values are as follows:

    • HTTP: Saml requests, and other session data collected as part of SAML flows and requests are kept in the http servlet session that is local to the server.
    • BROWSER_SESSION_STORAGE: Saml requests, and other session data collected as part of SAML flows and requests are kept in the client browser's session storage, signed and encrypted. SAML2 interactions require client-side read/write operations to restore the session from the browser.
    • TICKET_REGISTRY: Saml requests, and other session data collected as part of SAML flows and requests are tracked as CAS tickets in the registry and replicated across the entire cluster as tickets.

    This setting is owned by org.apereo.cas.configuration.model.support.saml.idp.SamlIdPCoreProperties.

    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.S ettings 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.

    Attribute Friendly Names

    Attribute friendly names can be specified per relying party in the service registry, as well as globally via CAS settings. If there is no friendly name defined for the attribute, the attribute name will be used instead in its place. Note that the name of the attribute is one that is designed to be released to the service provider, specially if the original attribute is mapped to a different name.

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    {
      "@class": "org.apereo.cas.support.saml.services.SamlRegisteredService",
      "serviceId" : "the-entity-id-of-the-sp",
      "name": "SAML Service",
      "metadataLocation" : "../../sp-metadata.xml",
      "id": 100001,