The Elasticsearch Destination for Elasticsearch 1.x includes Shield 1.3 support.
The Additional Configuration section of the stage configuration allows you to add the following properties:
shield.user = <username>:<password>
If you're using SSL/TLS, you will also need to specify these options as well:
shield.transport.ssl = true
Shield enables client cert verification by default if you enable SSL/TLS, so you need to specify these:
shield.ssl.keystore.path = /path/to/client.jks
shield.ssl.keystore.password = password
If you need to disable cert verification there's additional instructions about which properties to specify here: