Enterprise Single Sign-On for All

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Configure Service Access Strategy

The access strategy of a registered service provides fine-grained control over the service authorization rules. it describes whether the service is allowed to use the CAS server, allowed to participate in single sign-on authentication, etc. Additionally, it may be configured to require a certain set of principal attributes that must exist before access can be granted to the service. This behavior allows one to configure various attributes in terms of access roles for the application and define rules that would be enacted and validated when an authentication request from the application arrives.

Default

The default access manager allows one to configure a service with the following properties:

Field Description
enabled Flag to toggle whether the entry is active; a disabled entry produces behavior equivalent to a non-existent entry.
ssoEnabled Set to false to force users to authenticate to the service regardless of protocol flags (e.g. renew=true). This flag provides some support for centralized application of security policy.
requiredAttributes A Map of required principal attribute names along with the set of values for each attribute. These attributes must be available to the authenticated Principal and resolved before CAS can proceed, providing an option for role-based access control from the CAS perspective. If no required attributes are presented, the check will be entirely ignored.
requireAllAttributes Flag to toggle to control the behavior of required attributes. Default is true, which means all required attribute names must be present. Otherwise, at least one matching attribute name may suffice. Note that this flag only controls which and how many of the attribute names must be present. If attribute names satisfy the CAS configuration, at the next step at least one matching attribute value is required for the access strategy to proceed successfully.
unauthorizedRedirectUrl Optional url to redirect the flow in case service access is not allowed.
caseInsensitive Indicates whether matching on required attribute values should be done in a case-insensitive manner. Default is false
Are we sensitive to case?

Note that comparison of principal/required attribute names is case-sensitive. Exact matches are required for any individual attribute name.

Released Attributes

Note that if the CAS server is configured to cache attributes upon release, all required attributes must also be released to the relying party. See this guide for more info on attribute release and filters.

Time-Based

This access strategy is an extension of the default which additionally, allows one to configure a service with the following properties:

Field Description
startingDateTime Indicates the starting date/time whence service access may be granted. (i.e. 2015-10-11T09:55:16.552-07:00)
endingDateTime Indicates the ending date/time whence service access may be granted. (i.e. 2015-10-20T09:55:16.552-07:00)

Grouper

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

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<dependency>
  <groupId>org.jasig.cas</groupId>
  <artifactId>cas-server-integration-grouper</artifactId>
  <version>${cas.version}</version>
</dependency>

This access strategy attempts to locate Grouper groups for the CAS principal. The groups returned by Grouper are collected as CAS attribtues and examined against the list of required attributes for service access.

The following properties are available:

Field Description
groupField Decides which attribute of the Grouper group should be used when converting the group to a CAS attribute. Possible values are NAME, EXTENSION, DISPLAY_NAME, DISPLAY_EXTENSION.

You will also need to ensure grouper.client.properties is available on the classpath:

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grouperClient.webService.url = http://192.168.99.100:32768/grouper-ws/servicesRest
grouperClient.webService.login = banderson
grouperClient.webService.password = password

Configuration of Access Control

Some examples of RBAC configuration follow.

  • Service is not allowed to use CAS:
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{
  "@class" : "org.jasig.cas.services.RegexRegisteredService",
  "serviceId" : "testId",
  "name" : "testId",
  "id" : 1,
  "accessStrategy" : {
    "@class" : "org.jasig.cas.services.DefaultRegisteredServiceAccessStrategy",
    "enabled" : false,
    "ssoEnabled" : true
  }
}
  • Service will be challenged to present credentials every time, thereby not using SSO:
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{
  "@class" : "org.jasig.cas.services.RegexRegisteredService",
  "serviceId" : "testId",
  "name" : "testId",
  "id" : 1,
  "accessStrategy" : {
    "@class" : "org.jasig.cas.services.DefaultRegisteredServiceAccessStrategy",
    "enabled" : true,
    "ssoEnabled" : false
  }
}
  • To access the service, the principal must have a cn attribute with the value of admin AND a givenName attribute with the value of Administrator:
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{
  "@class" : "org.jasig.cas.services.RegexRegisteredService",
  "serviceId" : "testId",
  "name" : "testId",
  "id" : 1,
  "accessStrategy" : {
    "@class" : "org.jasig.cas.services.DefaultRegisteredServiceAccessStrategy",
    "enabled" : true,
    "ssoEnabled" : true,
    "requiredAttributes" : {
      "@class" : "java.util.HashMap",
      "cn" : [ "java.util.HashSet", [ "admin" ] ],
      "givenName" : [ "java.util.HashSet", [ "Administrator" ] ]
    }
  }
}
  • To access the service, the principal must have a cn attribute whose value is either of admin, Admin or TheAdmin.
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{
  "@class" : "org.jasig.cas.services.RegexRegisteredService",
  "serviceId" : "testId",
  "name" : "testId",
  "id" : 1,
  "accessStrategy" : {
    "@class" : "org.jasig.cas.services.DefaultRegisteredServiceAccessStrategy",
    "enabled" : true,
    "ssoEnabled" : true,
    "requiredAttributes" : {
      "@class" : "java.util.HashMap",
      "cn" : [ "java.util.HashSet", [ "admin, Admin, TheAdmin" ] ]
    }
  }
}
  • To access the service, the principal must have a cn attribute whose value is either of admin, Admin or TheAdmin, OR the principal must have a member attribute whose value is either of admins, adminGroup or staff.
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{
  "@class" : "org.jasig.cas.services.RegexRegisteredService",
  "serviceId" : "testId",
  "name" : "testId",
  "id" : 1,
  "accessStrategy" : {
    "@class" : "org.jasig.cas.services.DefaultRegisteredServiceAccessStrategy",
    "enabled" : true,
    "requireAllAttributes" : false,
    "ssoEnabled" : true,
    "requiredAttributes" : {
      "@class" : "java.util.HashMap",
      "cn" : [ "java.util.HashSet", [ "admin, Admin, TheAdmin" ] ],
      "member" : [ "java.util.HashSet", [ "admins, adminGroup, staff" ] ]
    }
  }
}
  • Service access is only allowed within startingDateTime and endingDateTime:
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{
  "@class" : "org.jasig.cas.services.RegexRegisteredService",
  "serviceId" : "^https://.+",
  "name" : "test",
  "id" : 62,
  "accessStrategy" : {
    "@class" : "org.jasig.cas.services.TimeBasedRegisteredServiceAccessStrategy",
    "enabled" : true,
    "ssoEnabled" : true,
    "unauthorizedRedirectUrl" : "https://www.github.com",
    "startingDateTime" : "2015-11-01T13:19:54.132-07:00",
    "endingDateTime" : "2015-11-10T13:19:54.248-07:00"
  }
}
  • Grouper access strategy based on group’s display extension:
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{
  "@class" : "org.jasig.cas.services.RegexRegisteredService",
  "serviceId" : "^https://.+",
  "name" : "test",
  "id" : 62,
  "accessStrategy" : {
    "@class" : "org.jasig.cas.grouper.services.GrouperRegisteredServiceAccessStrategy",
    "enabled" : true,
    "ssoEnabled" : true,
    "requireAllAttributes" : true,
    "requiredAttributes" : {
      "@class" : "java.util.HashMap",
      "memberOf" : [ "java.util.HashSet", [ "admin" ] ]
    },
    "groupField" : "DISPLAY_EXTENSION"
  }
}