Delegated Authentication

CAS can act as a client (i.e. service provider or proxy) using the Pac4j library and delegate the authentication to:

CAS servers
SAML2 identity providers
OAuth2 providers such as Facebook, Twitter, GitHub, Google, LinkedIn, etc
OpenID Connect identity providers such as Google, Apple
ADFS

Support is enabled by including the following dependency in the WAR overlay:

<dependency>
    <groupId>org.apereo.cas</groupId>
    <artifactId>cas-server-support-pac4j-webflow</artifactId>
    <version>${cas.version}</version>
</dependency>

implementation "org.apereo.cas:cas-server-support-pac4j-webflow:${project.'cas.version'}"

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

dependencies {
    implementation "org.apereo.cas:cas-server-support-pac4j-webflow"
}

dependencies {
    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-pac4j-webflow"
}

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.pac4j.core.groovy-authentication-request-customizer.location=` The location of the resource. Resources can be URLS, or files found either on the classpath or outside somewhere in the file system. In the event the configured resource is a Groovy script, specially if the script set to reload on changes, you may need to adjust the total number of `inotify` instances. On Linux, you may need to add the following line to `/etc/sysctl.conf`: `fs.inotify.max_user_instances = 256`. You can check the current value via `cat /proc/sys/fs/inotify/max_user_instances`. `org.apereo.cas.configuration.model.SpringResourceProperties.`
`cas.authn.pac4j.core.groovy-provider-post-processor.location=` The location of the resource. Resources can be URLS, or files found either on the classpath or outside somewhere in the file system. In the event the configured resource is a Groovy script, specially if the script set to reload on changes, you may need to adjust the total number of `inotify` instances. On Linux, you may need to add the following line to `/etc/sysctl.conf`: `fs.inotify.max_user_instances = 256`. You can check the current value via `cat /proc/sys/fs/inotify/max_user_instances`. `org.apereo.cas.configuration.model.SpringResourceProperties.`
`cas.authn.pac4j.core.groovy-redirection-strategy.location=` The location of the resource. Resources can be URLS, or files found either on the classpath or outside somewhere in the file system. In the event the configured resource is a Groovy script, specially if the script set to reload on changes, you may need to adjust the total number of `inotify` instances. On Linux, you may need to add the following line to `/etc/sysctl.conf`: `fs.inotify.max_user_instances = 256`. You can check the current value via `cat /proc/sys/fs/inotify/max_user_instances`. `org.apereo.cas.configuration.model.SpringResourceProperties.`
`cas.authn.pac4j.core.discovery-selection.json.location=` The location of the resource. Resources can be URLS, or files found either on the classpath or outside somewhere in the file system. In the event the configured resource is a Groovy script, specially if the script set to reload on changes, you may need to adjust the total number of `inotify` instances. On Linux, you may need to add the following line to `/etc/sysctl.conf`: `fs.inotify.max_user_instances = 256`. You can check the current value via `cat /proc/sys/fs/inotify/max_user_instances`. `org.apereo.cas.configuration.model.support.pac4j.Pac4jDelegatedAuthenticationDiscoverySelectionJsonProperties.`
`cas.authn.pac4j.core.discovery-selection.selection-type=MENU` Indicate how the selection and presentation of identity providers would be controlled. Available values are as follows: `MENU`: Defined identity providers will be listed for the user to select. `DYNAMIC`: Defined identity providers are pre-built first, and one is chosen dynamically at runtime based on user attributes properties, domain identifier, etc. `org.apereo.cas.configuration.model.support.pac4j.Pac4jDelegatedAuthenticationDiscoverySelectionProperties.`

_{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.pac4j.core.session-replication.replicate-sessions=true` Indicates whether profiles and other session data, collected as part of authentication flows and protocol requests that are kept by the container session, should be replicated across the cluster using CAS and its own ticket registry. Without this option, profile data and other related pieces of information should be manually replicated via means and libraries outside of CAS. `org.apereo.cas.configuration.model.support.replication.SessionReplicationProperties.`
`cas.authn.pac4j.core.session-replication.cookie.allowed-ip-addresses-pattern=` A regular expression pattern that indicates the set of allowed IP addresses, when `#isPinToSession()` is cofigured. In the event that there is a mismatch between the cookie IP address and the current request-provided IP address (i.e. network switches, VPN, etc), the cookie can still be considered valid if the new IP address matches the pattern specified here. `org.apereo.cas.configuration.model.support.replication.CookieSessionReplicationProperties.`
`cas.authn.pac4j.core.session-replication.cookie.auto-configure-cookie-path=true` Decide if cookie paths should be automatically configured based on the application context path, when the cookie path is not configured. `org.apereo.cas.configuration.model.support.replication.CookieSessionReplicationProperties.`
`cas.authn.pac4j.core.session-replication.cookie.comment=CAS Cookie` CAS Cookie comment, describes the cookie's usage and purpose. `org.apereo.cas.configuration.model.support.replication.CookieSessionReplicationProperties.`
`cas.authn.pac4j.core.session-replication.cookie.domain=` Cookie domain. Specifies the domain within which this cookie should be presented. The form of the domain name is specified by RFC 2965. A domain name begins with a dot (.foo.com) and means that the cookie is visible to servers in a specified Domain Name System (DNS) zone (for example, www.foo.com, but not a.b.foo.com). By default, cookies are only returned to the server that sent them. `org.apereo.cas.configuration.model.support.replication.CookieSessionReplicationProperties.`
`cas.authn.pac4j.core.session-replication.cookie.http-only=true` true if this cookie contains the HttpOnly attribute. This means that the cookie should not be accessible to scripting engines, like javascript. `org.apereo.cas.configuration.model.support.replication.CookieSessionReplicationProperties.`
`cas.authn.pac4j.core.session-replication.cookie.max-age=-1` The maximum age of the cookie, specified in seconds. By default, `-1` indicating the cookie will persist until browser shutdown. A positive value indicates that the cookie will expire after that many seconds have passed. Note that the value is the maximum age when the cookie will expire, not the cookie's current age. A negative value means that the cookie is not stored persistently and will be deleted when the Web browser exits. A zero value causes the cookie to be deleted. `org.apereo.cas.configuration.model.support.replication.CookieSessionReplicationProperties.`
`cas.authn.pac4j.core.session-replication.cookie.name=` Cookie name. Constructs a cookie with a specified name and value. The name must conform to RFC 2965. That means it can contain only ASCII alphanumeric characters and cannot contain commas, semicolons, or white space or begin with a `$` character. The cookie's name cannot be changed after creation. By default, cookies are created according to the RFC 2965 cookie specification. Cookie names are automatically calculated assigned by CAS at runtime, and there is usually no need to customize the name or assign it a different value unless a special use case warrants the change. `org.apereo.cas.configuration.model.support.replication.CookieSessionReplicationProperties.`
`cas.authn.pac4j.core.session-replication.cookie.path=` Cookie path. Specifies a path for the cookie to which the client should return the cookie. The cookie is visible to all the pages in the directory you specify, and all the pages in that directory's subdirectories. A cookie's path must include the servlet that set the cookie, for example, /catalog, which makes the cookie visible to all directories on the server under /catalog. Consult RFC 2965 (available on the Internet) for more information on setting path names for cookies. `org.apereo.cas.configuration.model.support.replication.CookieSessionReplicationProperties.`
`cas.authn.pac4j.core.session-replication.cookie.pin-to-session=true` When generating cookie values, determine whether the value should be compounded and signed with the properties of the current session, such as IP address, user-agent, etc. `org.apereo.cas.configuration.model.support.replication.CookieSessionReplicationProperties.`
`cas.authn.pac4j.core.session-replication.cookie.same-site-policy=` If a cookie is only intended to be accessed in a first party context, the developer has the option to apply one of settings `SameSite=Lax` or `SameSite=Strict` or `SameSite=None` to prevent external access. To safeguard more websites and their users, the new secure-by-default model assumes all cookies should be protected from external access unless otherwise specified. Developers must use a new cookie setting, `SameSite=None`, to designate cookies for cross-site access. When the `SameSite=None` attribute is present, an additional `Secure` attribute is used so cross-site cookies can only be accessed over HTTPS connections. Accepted values are: `Lax` `Strict` `None` `Off`: Disable the generation of the SamSite cookie attribute altogether. Fully qualified name of a class that implements `org.apereo.cas.web.cookie.CookieSameSitePolicy` `org.apereo.cas.configuration.model.support.replication.CookieSessionReplicationProperties.`
`cas.authn.pac4j.core.session-replication.cookie.secure=true` True if sending this cookie should be restricted to a secure protocol, or false if the it can be sent using any protocol. `org.apereo.cas.configuration.model.support.replication.CookieSessionReplicationProperties.`
`cas.authn.pac4j.core.cache-duration=PT8H` Control the expiration policy of the cache that holds onto the results. This settings supports the `java.time.Duration` syntax ^[?]. `org.apereo.cas.configuration.model.support.pac4j.Pac4jDelegatedAuthenticationCoreProperties.`
`cas.authn.pac4j.core.cache-size=100` Control the size of the delegated identity provider cache that holds identity providers. This setting specifies the maximum number of entries the cache may contain. Note that the cache may evict an entry before this limit is exceeded or temporarily exceed the threshold while evicting. As the cache size grows close to the maximum, the cache evicts entries that are less likely to be used again. For example, the cache may evict an entry because it hasn't been used recently or very often. `org.apereo.cas.configuration.model.support.pac4j.Pac4jDelegatedAuthenticationCoreProperties.`
`cas.authn.pac4j.core.lazy-init=true` Whether initialization of delegated identity providers should be done eagerly typically during startup. `org.apereo.cas.configuration.model.support.pac4j.Pac4jDelegatedAuthenticationCoreProperties.`
`cas.authn.pac4j.core.name=` The name of the authentication handler in CAS used for delegation. `org.apereo.cas.configuration.model.support.pac4j.Pac4jDelegatedAuthenticationCoreProperties.`
`cas.authn.pac4j.core.order=` Order of the authentication handler in the chain. `org.apereo.cas.configuration.model.support.pac4j.Pac4jDelegatedAuthenticationCoreProperties.`
`cas.authn.pac4j.core.principal-attribute-id=` The attribute to use as the principal identifier built during and upon a successful authentication attempt. `org.apereo.cas.configuration.model.support.pac4j.Pac4jDelegatedAuthenticationCoreProperties.`
`cas.authn.pac4j.core.typed-id-used=false` When constructing the final user profile from the delegated provider, determines if the provider id should be combined with the principal id. `org.apereo.cas.configuration.model.support.pac4j.Pac4jDelegatedAuthenticationCoreProperties.`