SubSonic is a pretty sweet application for streaming your music collection remotely to any browser, Android/iPhone device and more. FreeNAS is one of the best, if not the best, options for running a NAS in your home. However, you want to be secure so this will show you the not so straightforward setup to add SSL to your SubSonic install.
Make sure you have both a CA and a certificate (can be generated in System > CAs / System > Certificates). Download the .key and .crt for both and move them somewhere you can access them (in storage on your subsonic jail)
jlsto view jails which will return all your active jails with ids
jexec IDreplacing ID with the appropriate number
cat SubSonic.crt SubSonic.key SSH-CA.crt > subsonic.crt
openssl pkcs12 -in subsonic.crt -export -out subsonic.pkcs12
/usr/pbi/subsonic-amd64/bin/keytool -importkeystore -srckeystore subsonic.pkcs12 -destkeystore subsonic.keystore -srcstoretype PKCS12 -srcstorepass subsonic -srcalias 1 -destalias subsonic
cp subsonic.keystore /subsonic.keystore