It seems that currently HttpConnector reacts on trust store defined via "-Djavax.net.ssl.trustStore" so one can call HTTPS server which uses custom certificate. But when HTTPS server requires client certificate it seems that option "-Djavax.net.ssl.keyStore" is ignored. This should be improved.
Also, we should consider adding key/trust store path and password as HttpConnector properties. This way is much more safe than defining this parameters in scope of application server.