[Pki-users] Export keyPair and certificate to .p12 (private key with certificate) and .der (public key and certificate)

After creation certficate in application I have to return a certificate with private key. That file could be in .p12 format, am I right? Can I found example of create that file in existing code? there is a PKCS12Export command line tool but it propably works with existing creditentials on nssdatabase. Eventually I can get code from PKCS12Export and make addKeyBag() and few other methods public. Ok soo i have first part. And second part .der file is the same as certificate.getEncoded() if yes, thats allready done^^