SSO Cookie

A ticket-granting cookie is an HTTP cookie set by CAS upon the establishment of a single sign-on session. This cookie maintains login state for the client, and while it is valid, the client can present it to CAS in lieu of primary credentials.

The cookie value is linked to the active ticket-granting ticket, the remote IP address that initiated the request as well as the user agent that submitted the request. The final cookie value is then encrypted and signed.

These keys MUST be regenerated per your specific environment. Each key is a JSON Web Token with a defined length per the algorithm used for encryption and signing.

In the event that keys are not generated by the deployer, CAS will attempt to auto-generate keys and will output the result for each respective key. The deployer MUST attempt to copy the generated keys over to the appropriate settings in their CAS properties file, especially when running a multi-node CAS deployment. Failure to do so will prevent CAS to properly decrypt and encrypt the cookie value and will prevent successful single sign-on.

:information_source: Forced Authentication

Each application can opt out of a single sign-on session on a per-request basis. The availability of this behavior does depend on the authentication protocol used by the application. For example, applications that use the CAS protocol can opt out of single sign-on through the renew parameter or the CAS server may conditionally opt the service out based on the policies defined for the application in the service registry

Configuration

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

cas.tgc.crypto.encryption.keyThe encryption key is a string whose length is defined by the encryption key size setting.
no default
RequiredSpEL

The encryption key is a string whose length is defined by the encryption key size setting.

Type
String
Default
none
Defined by
EncryptionJwtCryptoProperties
Supports
Spring Expression Language
cas.tgc.crypto.signing.keyThe signing key is a string whose length is defined by the signing key size setting.
no default
RequiredSpEL

The signing key is a string whose length is defined by the signing key size setting.

Type
String
Default
none
Defined by
SigningJwtCryptoProperties
Supports
Spring Expression Language
cas.tgc.allowed-ip-addresses-patternA regular expression pattern that indicates the set of allowed IP addresses, when #isPinToSession() is configured.
no default
Regex

A regular expression pattern that indicates the set of allowed IP addresses, when #isPinToSession() is configured. 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.

Type
String
Default
none
Defined by
TicketGrantingCookieProperties
cas.tgc.auto-configure-cookie-pathDecide if cookie paths should be automatically configured based on the application context path, when the cookie path is not configured.
true

Decide if cookie paths should be automatically configured based on the application context path, when the cookie path is not configured.

Type
Boolean
Default
true
Defined by
TicketGrantingCookieProperties
cas.tgc.crypto.algThe signing/encryption algorithm to use.
no default

The signing/encryption algorithm to use.

Type
String
Default
none
Defined by
EncryptionOptionalSigningOptionalJwtCryptographyProperties
cas.tgc.crypto.enabledWhether crypto operations are enabled.
true

Whether crypto operations are enabled.

Type
Boolean
Default
true
Defined by
EncryptionOptionalSigningOptionalJwtCryptographyProperties
cas.tgc.crypto.encryption-enabledWhether crypto encryption operations are enabled.
true

Whether crypto encryption operations are enabled.

Type
Boolean
Default
true
Defined by
EncryptionOptionalSigningOptionalJwtCryptographyProperties
cas.tgc.crypto.encryption.key-sizeThe encryption key size.
512

The encryption key size.

Type
Integer
Default
512
Defined by
EncryptionJwtCryptoProperties
cas.tgc.crypto.signing-enabledWhether crypto signing operations are enabled.
true

Whether crypto signing operations are enabled.

Type
Boolean
Default
true
Defined by
EncryptionOptionalSigningOptionalJwtCryptographyProperties
cas.tgc.crypto.signing.key-sizeThe signing key size.
512

The signing key size.

Type
Integer
Default
512
Defined by
SigningJwtCryptoProperties
cas.tgc.crypto.strategy-typeControl the cipher sequence of operations.
ENCRYPT_AND_SIGN
Control the cipher sequence of operations. The accepted values are:
  • ENCRYPT_AND_SIGN: Encrypt the value first, and then sign.
  • SIGN_AND_ENCRYPT: Sign the value first, and then encrypt.
Type
String
Default
ENCRYPT_AND_SIGN
Defined by
EncryptionOptionalSigningOptionalJwtCryptographyProperties
cas.tgc.domainCookie domain.
no default

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.

Type
String
Default
none
Defined by
TicketGrantingCookieProperties
cas.tgc.geo-locate-client-sessionWhen set to true and assuming #isPinToSession() is also true , client sessions (using the client IP address) are geo-located using a geolocation service when/if configured.
false

When set to true and assuming #isPinToSession() is also true, client sessions (using the client IP address) are geo-located using a geolocation service when/if configured. The resulting session is either pinned to the client geolocation, or the default client address.

Type
Boolean
Default
false
Defined by
TicketGrantingCookieProperties
cas.tgc.http-onlytrue if this cookie contains the HttpOnly attribute.
true

true if this cookie contains the HttpOnly attribute. This means that the cookie should not be accessible to scripting engines, like javascript.

Type
Boolean
Default
true
Defined by
TicketGrantingCookieProperties
cas.tgc.max-ageThe maximum age of the cookie, specified in seconds.
-1
Duration

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.

Type
String
Default
-1
Defined by
TicketGrantingCookieProperties
cas.tgc.nameCookie name.
no default

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.

Type
String
Default
none
Defined by
TicketGrantingCookieProperties
cas.tgc.pathCookie path.
no default

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.

Type
String
Default
none
Defined by
TicketGrantingCookieProperties
cas.tgc.pin-to-sessionWhen 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.
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.

Turning off session pinning is not exactly ideal. This is a barrier to prevent cookie replay attacks. A cookie that was created with an IP given a certain location cannot be replayed back in a different browser with a different IP from a different location.

There may however be legitimate reasons to turn it off and relax this after careful reviews, if you intend to support a type of user who intends to switch their IP quite frequently. A classic example is the type of user that is on VPN at the time of login, but decides to resume their work a few hours later off VPN or at a different location.

Type
Boolean
Default
true
Defined by
TicketGrantingCookieProperties
cas.tgc.remember-me-max-ageIf remember-me is enabled, specifies the maximum age of the cookie.
P14D
Duration

If remember-me is enabled, specifies the maximum age of the cookie.

Type
String
Default
P14D
Defined by
TicketGrantingCookieProperties
cas.tgc.same-site-policyIf 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.
no default

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 SameSite cookie attribute altogether.
  • Path to a Groovy script that is able to generate the SameSite cookie attribute dynamically.
  • Fully qualified name of a class that implements org.apereo.cas.web.cookie.CookieSameSitePolicy
Type
String
Default
none
Defined by
TicketGrantingCookieProperties
cas.tgc.secureTrue if sending this cookie should be restricted to a secure protocol, or false if the it can be sent using any protocol.
true

True if sending this cookie should be restricted to a secure protocol, or false if the it can be sent using any protocol.

Type
Boolean
Default
true
Defined by
TicketGrantingCookieProperties

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.

Signing & encryption

This CAS feature is able to accept signing and encryption crypto keys. In most scenarios if keys are not provided, CAS will auto-generate them. The following instructions apply if you wish to manually and beforehand create the signing and encryption keys.

Note that if you are asked to create a JWK of a certain size for the key, you are to use the following set of commands to generate the token:

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wget https://raw.githubusercontent.com/apereo/cas/master/etc/jwk-gen.jar
java -jar jwk-gen.jar -t oct -s [size]

The outcome would be similar to:

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{
  "kty": "oct",
  "kid": "...",
  "k": "..."
}

The generated value for k needs to be assigned to the relevant CAS settings. Note that keys generated via the above algorithm are processed by CAS using the Advanced Encryption Standard (AES) algorithm which is a specification for the encryption of electronic data established by the U.S. National Institute of Standards and Technology.


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.

The cookie has the following properties:

  1. It is marked as secure.
  2. Depending on container support, the cookie would be marked as http-only automatically.
  3. The cookie value is encrypted and signed via secret keys that need to be generated upon deployment.

If keys are left undefined, on startup CAS will notice that no keys are defined and it will appropriately generate keys for you automatically. Your CAS logs will then show the following snippet:

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WARN [...] - <Secret key for encryption is not defined. CAS will auto-generate the encryption key>
WARN [...] - <Generated encryption key ABC of size ... . The generated key MUST be added to CAS settings.>
WARN [...] - <Secret key for signing is not defined. CAS will auto-generate the signing key>
WARN [...] - <Generated signing key XYZ of size ... . The generated key MUST be added to CAS settings.>

You should then grab each generated key for encryption and signing, and put them inside your CAS properties for each setting. If you wish you manually generate keys, you may use the following tool.

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

cas.sso.mail.attribute-namePrincipal attribute names that indicates the destination email address for this message.
no default
RequiredSpEL

Principal attribute names that indicates the destination email address for this message. The attributes must already be resolved and available to the CAS principal. When multiple attributes are specified, each attribute is then examined against the available CAS principal to locate the email address value, which may result in multiple emails being sent.

Type
List<String>
Default
none
Defined by
EmailProperties
Supports
Spring Expression Language
cas.sso.mail.fromEmail from address.
no default
Required

Email from address.

Type
String
Default
none
Defined by
EmailProperties
cas.sso.mail.subjectEmail subject line.
no default
RequiredSpEL

Email subject line.

The subject can either be defined verbatim, or it may point to a message key in the language bundle using the syntax #{subject-language-key}. This key should point to a valid message defined in the appropriate language bundle that is then picked up via the active locale. In case where the language code cannot resolve the real subject, a default subject value would be used.

Type
String
Default
none
Defined by
EmailProperties
Supports
Spring Expression Language
cas.sso.sms.attribute-namePrincipal attribute names that indicates the destination phone number for this SMS message.
no default
RequiredSpEL

Principal attribute names that indicates the destination phone number for this SMS message. The attribute must already be resolved and available to the CAS principal.

Type
List<String>
Default
none
Defined by
SmsProperties
Supports
Spring Expression Language
cas.sso.sms.fromThe from address for the message.
no default
Required

The from address for the message.

Type
String
Default
none
Defined by
SmsProperties
cas.sso.sms.textThe body of the SMS message.
no default
Required

The body of the SMS message.

Type
String
Default
none
Defined by
SmsProperties
cas.sso.create-sso-cookie-on-renew-authnFlag that indicates whether to create SSO session on re-newed authentication event.
true

Flag that indicates whether to create SSO session on re-newed authentication event.

Type
Boolean
Default
true
Defined by
SingleSignOnProperties
cas.sso.mail.bccEmail BCC address, if any.
no default

Email BCC address, if any.

Type
List<String>
Default
none
Defined by
EmailProperties
cas.sso.mail.ccEmail CC address, if any.
no default

Email CC address, if any.

Type
List<String>
Default
none
Defined by
EmailProperties
cas.sso.mail.htmlIndicate whether the message body should be evaluated as HTML text.
false

Indicate whether the message body should be evaluated as HTML text. The application of this setting depends on the email provider implementation and may not be fully supported everywhere. This is typically relevant for the default org.springframework.mail.javamail.JavaMailSender.

Type
Boolean
Default
false
Defined by
EmailProperties
cas.sso.mail.prioritySet the priority ( X-Priority header) of the message.
1

Set the priority (X-Priority header) of the message. Values: 1 (Highest), 2 (High), 3 (Normal), 4 (Low), 5 (Lowest). The application of this setting depends on the email provider implementation and may not be fully supported everywhere. This is typically relevant for the default org.springframework.mail.javamail.JavaMailSender.

Type
Integer
Default
1
Defined by
EmailProperties
cas.sso.mail.reply-toEmail Reply-To address, if any.
no default

Email Reply-To address, if any.

Type
String
Default
none
Defined by
EmailProperties
cas.sso.mail.textEmail message body.
no default

Email message body. Could be plain text or a reference to an external file that would serve as a template.

If specified as a path to an external file with an extension .gtemplate, then the email message body would be processed using the Groovy template engine. The template engine uses JSP style <% %> script and <%= %> expression syntax or GString style expressions. The variable out is bound to the writer that the template is being written to.

If using plain text, the contents are processed for string substitution candidates using named variables. For example, you may refer to an expected url variable in the email text via ${url}, or use ${token} to locate the token variable. In certain cases, additional parameters are passed to the email body processor that might include authentication and/or principal attributes, the available locale, client http information, etc.

Type
String
Default
none
Defined by
EmailProperties
cas.sso.mail.validate-addressesSet whether to validate all addresses which get passed to this helper.
false

Set whether to validate all addresses which get passed to this helper. The application of this setting depends on the email provider implementation and may not be fully supported everywhere. This is typically relevant for the default org.springframework.mail.javamail.JavaMailSender.

Type
Boolean
Default
false
Defined by
EmailProperties
cas.sso.proxy-authn-enabledIndicates whether CAS proxy authentication/tickets are supported by this server implementation.
true

Indicates whether CAS proxy authentication/tickets are supported by this server implementation.

Type
Boolean
Default
true
Defined by
SingleSignOnProperties
cas.sso.renew-authn-enabledIndicates whether this server implementation should globally support CAS protocol authentication requests that are tagged with "renew=true".
true

Indicates whether this server implementation should globally support CAS protocol authentication requests that are tagged with "renew=true".

Type
Boolean
Default
true
Defined by
SingleSignOnProperties
cas.sso.revocation-attribute-nameAttribute name that represents a Unix epoch value in seconds.
no default

Attribute name that represents a Unix epoch value in seconds. This timestamp signifies the demarcation point such that any authentication attempts that were created prior to that time are treated as revoked and SSO will be ignored. Calculations are based on the UTC timezone. The attribute is only read and never modified/updated by CAS.

Type
String
Default
none
Defined by
SingleSignOnProperties
cas.sso.services.allow-missing-service-parameterFlag that indicates whether to allow SSO session with a missing target service.
true

Flag that indicates whether to allow SSO session with a missing target service.

By default, CAS will present a generic success page if the initial authentication request does not identify the target application. In some cases, the ability to login to CAS without logging in to a particular service may be considered a misfeature because in practice, too few users and institutions are prepared to understand, brand, and support what is at best a fringe use case of logging in to CAS for the sake of establishing an SSO session without logging in to any CAS-reliant service.

Type
Boolean
Default
true
Defined by
SingleSignOnServicesProperties
cas.sso.services.required-service-patternA regular expression pattern that represents an application which must have established a session with CAS already before access to other applications can be allowed by CAS.
no default
Regex

A regular expression pattern that represents an application which must have established a session with CAS already before access to other applications can be allowed by CAS. This is the initial mandatory/required application with which the user must start before going anywhere else. Services that establish a session with CAS typically do so by receiving a service ticket from CAS.

Type
String
Default
none
Defined by
SingleSignOnServicesProperties
cas.sso.sso-enabledIndicate whether single sign-on should be turned on and supported globally for the server.
true

Indicate whether single sign-on should be turned on and supported globally for the server.

Type
Boolean
Default
true
Defined by
SingleSignOnProperties

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.

Email servers

The following settings may also need to be defined to describe the mail server settings:

spring.mail.default-encodingDefault MimeMessage encoding.
UTF-8
Third party

Default MimeMessage encoding.

Type
Charset
Default
UTF-8
Defined by
MailProperties
spring.mail.hostSMTP server host.
no default
Third party

SMTP server host. For instance, 'smtp.example.com'.

Type
String
Default
none
Defined by
MailProperties
spring.mail.jndi-nameSession JNDI name.
no default
Third party

Session JNDI name. When set, takes precedence over other Session settings.

Type
String
Default
none
Defined by
MailProperties
spring.mail.passwordLogin password of the SMTP server.
no default
Third party

Login password of the SMTP server.

Type
String
Default
none
Defined by
MailProperties
spring.mail.portSMTP server port.
no default
Third party

SMTP server port.

Type
Integer
Default
none
Defined by
MailProperties
spring.mail.propertiesAdditional JavaMail Session properties.
no default
Third party

Additional JavaMail Session properties.

Type
Map<String,String>
Default
none
Defined by
MailProperties
spring.mail.protocolProtocol used by the SMTP server.
smtp
Third party

Protocol used by the SMTP server.

Type
String
Default
smtp
Defined by
MailProperties
spring.mail.ssl.bundleSSL bundle name.
no default
Third party

SSL bundle name. If set, 'mail.(protocol).ssl.socketFactory' property is set to an SSLSocketFactory obtained from the corresponding SSL bundle.

Note that the STARTTLS command can use the corresponding SSLSocketFactory, even if the 'mail.(protocol).ssl.enable' property is not set.

Type
String
Default
none
Defined by
MailProperties$Ssl
spring.mail.ssl.enabledWhether to enable SSL support.
false
Third party

Whether to enable SSL support. If enabled, 'mail.(protocol).ssl.enable' property is set to 'true'.

Type
Boolean
Default
false
Defined by
MailProperties$Ssl
spring.mail.ssl.verify-hostnameWhether to enable hostname verification.
true
Third party

Whether to enable hostname verification.

Type
Boolean
Default
true
Defined by
MailProperties$Ssl
spring.mail.test-connectionWhether to test that the mail server is available on startup.
false
Third party

Whether to test that the mail server is available on startup.

Type
Boolean
Default
false
Defined by
MailSenderValidatorAutoConfiguration
spring.mail.usernameLogin user of the SMTP server.
no default
Third party

Login user of the SMTP server.

Type
String
Default
none
Defined by
MailProperties
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.

SSO Expiration Policy

The single sign-on expiration policy that is tied to the CAS single sign-on cookie is mainly controlled by a specific ticket type that represents the single sign-on session managed by the CAS server.

See this page for more.

SameSite Attribute

CAS configuration allows the deployer to control and modify the SameAttribute cookie attribute statically. The deployer also has the option to generate this cookie attribute dynamically via the following strategies.

  • The cookie setting in CAS configuration may point to a Groovy script that is tasked to generate the SameAttribute cookie attribute. The outline of the script may be as follows:

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    import org.apereo.cas.web.cookie.*
    
    def run(final Object... args) {
        def (request,response,context,logger) = args
        
        logger.info("Generating SameSite for ${context.name}")
        return "SameSite=Lax;"
    }
    

    The parameters that may be passed are as follows:

    Parameter Description
    request The HTTP request object.
    response The HTTP response object.
    context The cookie configuration context that points to the cookie configuration and other helper objects.
    logger The object responsible for issuing log messages such as logger.info(...).
  • The cookie setting in CAS configuration may point to a Java class using its FQDN that is tasked to generate the SameAttribute cookie attribute.

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    public class MyCookieSameSitePolicy implements CookieSameSitePolicy {
        @Override
        public Optional<String> build(HttpServletRequest request, 
                                      HttpServletResponse response, 
                                      CookieGenerationContext context) {
            return Optional.of("SameSite=Lax;");
        }
    }
    

By default, forced authentication requests that challenge the user for credentials either via the renew request parameter (that is, using the CAS protocol), or via the service-specific setting of the CAS service registry will always generate the ticket-granting cookie nonetheless. What this means is, logging in to a non-SSO-participating application via CAS nonetheless creates a valid CAS single sign-on session that will be honored on a subsequent attempt to authenticate to a SSO-participating application.

The cookie generation strategy can also be customized on a per-application basis. For additional details, please review this guide.