Excuse me if this is a silly question, but you are able to secure Elasticsearch using SSL certificate and authorities rather than keystores, but it seems you can't set up Logstash to talk to Elasticsearch in the same way.
I currently have ES using SSL certificate, ca and key and want to have Logstash to be able to talk to the cluster in the same manner but these docs don't list parameters for crt, key:
https://www.elastic.co/guide/en/logstash/current/plugins-outputs-elasticsearch.html
Can anyone confirm if you can only use trust stores with logstash > elasticsearch?