Thanks for your help, but it does not suffice to return persistentId only in subject (username) section of saml response.
I need also to return eduPersonTargetedID as a separate attribute in the AttributeStatement section like this:
{
"@class": "org.apereo.cas.support.saml.services.SamlRegisteredService",
"serviceId": "^https://.+$",
"name": "federation",
"id": 1999,
"evaluationOrder": 1999,
"metadataLocation": "
https://aai.pionier.net.pl/pionierid-edugain-sp-feed.xml",
"usernameAttributeProvider" : {
"@class" : "org.apereo.cas.services.AnonymousRegisteredServiceUsernameAttributeProvider",
"persistentIdGenerator" : {
"@class" : "org.apereo.cas.authentication.principal.ShibbolethCompatiblePersistentIdGenerator",
"salt" : "abc",
"attribute": "uidNumber"
}
},
"attributeReleasePolicy": {
"@class": "org.apereo.cas.services.ChainingAttributeReleasePolicy",
"policies": [ "java.util.ArrayList",
[
{
"@class": "org.apereo.cas.support.saml.services.EduPersonTargetedIdAttributeReleasePolicy",
"salt" : "abc",
"attribute": "uidNumber"
}
]
]
}
}