private X509Certificate getRecipient() throws Exception {
GetCaCertRequest req = new GetCaCertRequest();
Transport transport = new HttpGetTransport(getURL());
CertStore store = transport.sendRequest(req,
new GetCaCertResponseHandler());
Collection<? extends Certificate> certs = store.getCertificates(null);
if (certs.size() > 0) {
return (X509Certificate) certs.iterator().next();
} else {