Java client certificates over HTTPS/SSL

Question

I am using Java 6 and am trying to create an HttpsURLConnection against a remote server, using a client certificate.
The server is using an selfsigned root

Answer 1

Finally solved it ;). Got a strong hint here (Gandalfs answer touched a bit on it as well). The missing links was (mostly) the first of the parameters below, and to some extent that I overlooked the difference between keystores and truststores.

The self-signed server certificate must be imported into a truststore:

keytool -import -alias gridserver -file gridserver.crt -storepass $PASS -keystore gridserver.keystore

These properties need to be set (either on the commandline, or in code):

-Djavax.net.ssl.keyStoreType=pkcs12
-Djavax.net.ssl.trustStoreType=jks
-Djavax.net.ssl.keyStore=clientcertificate.p12
-Djavax.net.ssl.trustStore=gridserver.keystore
-Djavax.net.debug=ssl # very verbose debug
-Djavax.net.ssl.keyStorePassword=$PASS
-Djavax.net.ssl.trustStorePassword=$PASS

Working example code:

SSLSocketFactory sslsocketfactory = (SSLSocketFactory) SSLSocketFactory.getDefault();
URL url = new URL("https://gridserver:3049/cgi-bin/ls.py");
HttpsURLConnection conn = (HttpsURLConnection)url.openConnection();
conn.setSSLSocketFactory(sslsocketfactory);
InputStream inputstream = conn.getInputStream();
InputStreamReader inputstreamreader = new InputStreamReader(inputstream);
BufferedReader bufferedreader = new BufferedReader(inputstreamreader);

String string = null;
while ((string = bufferedreader.readLine()) != null) {
    System.out.println("Received " + string);
}