Generate key pair, pass phrase will be asked
openssl genrsa -aes128 -out jetty.key
Generate a certificate for the key generated above (you should know the pass phrase for the key).
You will be asked to enter some info about you/your org to build a Distinguished Name (DN).
The only mandatory response to provide is the fully qualified host name of the server at the "Common Name".
Note that i used -days 365
option to make certificate valid for one year, change as needed