Please refer this document - https://dev.liferay.com/en/discover/deployment/-/knowledge_base/7-1/token-based-single-sign-on-authentication
Where to find Siteminder Configurations:
"Token based authentication is disabled by default. To manage token based SSO authentication, navigate to Liferay Portal’s Control Panel, click on System Settings, → Security → SSO. Token Based SSO appears in the list at the bottom. Alternately, you can search for Token in the Search field."
According to above document link - there are various token based options to integrate with SSO solutions. One of the Siteminder supported mechanism is "HTTP request header" based.
This is how your configuration should look like on LifeRay Portal:
Authentication cookies: SMIDENTITY
, SMSESSION
Enabled: Checked
Import from LDAP: < Check this box to automatically import users from LDAP if they do not exist in the portal. (This may not be required, but you need to understand the requirement and make decision). >
Logout redirect URL: <When user logs out of Liferay Portal, the user is redirected to this URL.>
Token location: HTTP request header
User token name: SM_USER
Additional info:
On siteminder/SSO side -you need to take care of Userdirectory/Agent/ACO/Domain/Realm/Rules/Policies...etc.
SM_USER is a default HTTP header set by Siteminder webagent for applications to make use of it.
Default HTTP Headers Used by the Product - CA Single Sign-On - 12.7 - CA Technologies Documentation
Hope this helps !!!, Let me know, if you have further questions on this.
Regards
Ashok