Adaptive Authentication
Adaptive authentication in CAS allows you to accept or reject authentication requests based on certain characteristics
of the client browser and/or device. When configured, you are provided with options to block authentication requests
from certain locations submitted by certain browser agents. For instance, you may consider authentication requests submitted
from London, UK to be considered suspicious, or you may want to block requests that are submitted from Internet Explorer, etc.
Adaptive authentication can also be configured to trigger multifactor based on specific days and times. For example, you may wish to trigger multifactor on select days or if the current hour is after 11pm or before 6am. Each rule block may be assigned to an mfa provider where successful matching of rules allows for the multifactor trigger to execute.
You might also be interested in reviewing Risk-based Authentication.
Configuration
The following settings and properties are available from the CAS configuration catalog:
cas.authn.adaptive.policy.require-timed-multifactor[0].provider-idThe mfa provider id that should be triggered.
The mfa provider id that should be triggered.
cas.authn.adaptive.policy.reject-browsersComma-separated list of strings representing browser user agents to be rejected from participating in authentication transactions.
Comma-separated list of strings representing browser user agents to be rejected from participating in authentication transactions.
cas.authn.adaptive.policy.reject-countriesComma-separated list of strings representing countries to be rejected from participating in authentication transactions.
Comma-separated list of strings representing countries to be rejected from participating in authentication transactions.
cas.authn.adaptive.policy.reject-ip-addressesComma-separated list of strings representing IP addresses to be rejected from participating in authentication transactions.
Comma-separated list of strings representing IP addresses to be rejected from participating in authentication transactions.
cas.authn.adaptive.policy.require-multifactorA map of ( mfaProviderId -> adaptiveRegexPattern ) that tells CAS when to trigger an MFA authentication transaction.
A map of (mfaProviderId -> adaptiveRegexPattern) that tells CAS when to trigger an MFA authentication transaction.
This property binds a valid mfa provider to an adaptive regex pattern representing either IP address, user-agent or geolocation. When either of those collected pieces of adaptive data matches configured regex pattern during authentication event, an MFA authentication transaction is triggered for an MFA provider represented by the map's key.
cas.authn.adaptive.policy.require-timed-multifactorThis property binds a valid mfa provider to a collection of rules that deal with triggering mfa based on that provider based on properties of date/time.
This property binds a valid mfa provider to a collection of rules that deal with triggering mfa based on that provider based on properties of date/time. One may want to force mfa during weekends, after hours, etc and the ruleset provides a modest configuration set where time can also be treated as trigger.
cas.authn.adaptive.policy.require-timed-multifactor[0].on-daysTrigger mfa on the following days of the week.
Trigger mfa on the following days of the week.
cas.authn.adaptive.policy.require-timed-multifactor[0].on-or-after-hourTrigger mfa after this hour, specified in 24-hour format.
20Trigger mfa after this hour, specified in 24-hour format.
cas.authn.adaptive.policy.require-timed-multifactor[0].on-or-before-hourTrigger mfa before this hour, specified in 24-hour format.
7Trigger mfa before this hour, specified in 24-hour format.
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.
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.
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.
To enable adaptive authentication, you will need to allow CAS to geo-locate authentication requests. To learn more, please see this guide
IP Intelligence
CAS provides you with the capability to examine the client IP address and decide whether access should be granted. This may be useful to detect bot, proxy or VPN traffic and protect your deployment from fraud, automated attacks, crawlers, etc.
To learn more, please see this guide.