You can create an identity assertion trust by using the Admin Console or CLI.
In the Admin Console, expand the Configurations node and select a configuration. Expand the Security node, click Trust Configurations and then click New.
Alternatively, you can use the asadmin create-trusted-entity and asadmin create-trust-config command. See TBDlink for more details about this command.
You can associate trusted entities (trusted hosts/domains) with a trust configuration or you can select a Trust Handler to have custom implementations to determine trust.