[FEATURE] Support subject key in a nested claim within JWT #5430
Description
Similar to how we support abstraction of the roles_key configuration as list for config to get roles, we can also add abstraction for subject_key 5355
What solution would you like?
Abstracts the sub_key configuration from jwt-backed auth backends to handle a list as config to get sub within nested claims of a JWT payload similar to the abstracts roles_key.
#5355
Do you have any additional context?
https://forum.opensearch.org/t/access-nested-fields-in-jwt-token-for-subject-key-roles-key/811/7
subject_key: context.user.name
roles_key: context.user.policies