Simple Multifactor Authentication - Token Management
Token management and issuance can be handled by CAS directly, or can be outsources to external systems and services.
Default
By default, tokens issued by CAS are tracked using the ticket registry and are assigned a configurable expiration policy controlled via CAS settings. In this option, CAS itself is in charge of managing and validating tokens using pre-configured policies and components.
The following settings and properties are available from the CAS configuration catalog:
cas.authn.mfa.simple.token.core.time-to-kill-in-seconds=30
Time in seconds that CAS tokens should be considered live in CAS server.
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cas.authn.mfa.simple.token.core.token-length=6
The length of the generated token.
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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. 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.
REST
Token validation and management can also be outsources to an external REST API.
The following settings and properties are available from the CAS configuration catalog:
cas.authn.mfa.simple.token.rest.url=
The endpoint URL to contact and retrieve attributes.
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cas.authn.mfa.simple.token.rest.basic-auth-password=
If REST endpoint is protected via basic authentication, specify the password for authentication.
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cas.authn.mfa.simple.token.rest.basic-auth-username=
If REST endpoint is protected via basic authentication, specify the username for authentication.
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cas.authn.mfa.simple.token.rest.headers=
Headers, defined as a Map, to include in the request when making the REST call. Will overwrite any header that CAS is pre-defined to send and include in the request. Key in the map should be the header name and the value in the map should be the header value.
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cas.authn.mfa.simple.token.rest.method=GET
HTTP method to use when contacting the rest endpoint. Examples include
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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. 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.
The API service is primarily response for two operations: issuing tokens so they may be shared with the end-user and validating tokens once the end-user provides them back to CAS.
Generating Tokens
When tokens need to be generated, this API endpoint would be invoked via a GET to create the ticket identifier. The body of
the request will contain the authenticated principal that is put through the multifactor authentication flow,
and the requesting application for which the token should be generated is passed to the API via a service parameter.
The endpoint is expected to respond to token generation requests at a /new URL path suffix, and should produce a 2xx
status code where the response body is expected to contain the token identifier.
Storing Tokens
Generated tokens, that are shared with end-users, can be stored via the REST API endpoint using a POST. The body of the request
would contain the actual token definition and details that should be stored. The API service should produce a 2xx
status code on successful operations.
Validating Tokens
Generated tokens are passed to this API to validation where the token is appended to the URL endpoint and acts as a path variable. The response
that is returned to a GET call must be accompanied by a 2xx status code where the body should contain id and attributes fields, the
latter being optional, which represent the authenticated principal for CAS:
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{
"@class": "org.apereo.cas.authentication.principal.SimplePrincipal",
"id": "casuser",
"attributes": {
"@class": "java.util.LinkedHashMap",
"names": [
"java.util.List", ["cas", "user"]
]
}
}
Custom
You may also define your own multifactor authentication service using the following
bean definition and by implementing CasSimpleMultifactorAuthenticationService:
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@Bean
public CasSimpleMultifactorAuthenticationService casSimpleMultifactorAuthenticationService() {
return new MyCasSimpleMultifactorAuthenticationService();
}
See this guide to learn more about how to register configurations into the CAS runtime.