encGen.addKeyTransRecipient(origCert);
MimeBodyPart mp = encGen.generate(msg, SMIMEEnvelopedGenerator.AES128_CBC, "BC");
SMIMEEnveloped env = new SMIMEEnveloped(mp);
RecipientInformation ri = (RecipientInformation)env.getRecipientInfos().getRecipients().iterator().next();
MimeBodyPart mm = SMIMEUtil.toMimeBodyPart(ri.getContentStream(origKP.getPrivate(), "BC"));
SMIMESigned s = new SMIMESigned((MimeMultipart)mm.getContent());
Collection c = s.getSignerInfos().getSigners();
Iterator it = c.iterator();
CertStore certs = s.getCertificatesAndCRLs("Collection", "BC");