Hi,
You can use the CertificateGenerator program in UniversalMessaging\server\umserver\bin to generate the client/server/nirvanacerts jks files (check the docs and the necessary adjustments to the client installations).
I usually use the KeyStore Explorer to create my keys and customize it to my needs (adding CA, setting a different CN, etc.). It also helps to convert jks files to p12 files needed by Windows.
Best Regards,
#webMethods#Universal-Messaging-Broker#Integration-Server-and-ESB