sslClient: the certificate is selectable by the client
the certificate can be used for mime encryption.
(perhaps the above should be settable. It is not clear that most certs should be used that way, as their life
span could be very short)
*/
certGenerator.addExtension(MiscObjectIdentifiers.netscapeCertType,
false, new NetscapeCertType(NetscapeCertType.sslClient
| NetscapeCertType.smime));
/*
* Adds the authority key identifier extension.