I have a Java application that runs on Windows Mobile devices using a 3rd Party JVM. The application communicates with an Apache Tomcat server over HTTP. We have also used HTTPS for some connections and the certificates were created using the Sun keytool utility. First a keystore was created using genkey, then the certificate exported using export and finally that was imported into another keystore using import. The file created by genkey was loaded into the Apache server and the keystore created using import was loaded into the JVM on the PDA. Everything works as expected.

I am now working with a new JVM on the PDA and (for whatever reason) I have established that this JVM requires the keystore to be in X509 (DER) format. I started working on this about a month ago and had it working, but stupidly never wrote down the steps I took, and now I can't for the life of me remember what I did. I seem to remember using openssl but other than that I am totally lost. Anything I create now using openssl and try to load into Apache causes an error at startup (Invalid Keystore Format) so I am probably missing something out entirely.

Does anyone have any ideas how I should be going about creating this self-signed X509 certificate that can be loaded into Apache server and JVM running on a PDA?