private KeyTransRecipientInfo computeRecipientInfo(X509Certificate x509certificate, byte[] abyte0)
throws GeneralSecurityException, IOException {
ASN1InputStream asn1inputstream =
new ASN1InputStream(new ByteArrayInputStream(x509certificate.getTBSCertificate()));
TBSCertificateStructure tbscertificatestructure =
TBSCertificateStructure.getInstance(asn1inputstream.readObject());
AlgorithmIdentifier algorithmidentifier =
tbscertificatestructure.getSubjectPublicKeyInfo().getAlgorithmId();
IssuerAndSerialNumber issuerandserialnumber =
new IssuerAndSerialNumber(
tbscertificatestructure.getIssuer(),
tbscertificatestructure.getSerialNumber().getValue());
Cipher cipher = Cipher.getInstance(algorithmidentifier.getObjectId().getId());
cipher.init(1, x509certificate.getPublicKey());
DEROctetString deroctetstring = new DEROctetString(cipher.doFinal(abyte0));
RecipientIdentifier recipId = new RecipientIdentifier(issuerandserialnumber);
return new KeyTransRecipientInfo(recipId, algorithmidentifier, deroctetstring);
}
/**
* Extracts the TBS certificate from the given certificate.
*
* @param cert the X.509 certificate to extract the TBS certificate from.
* @return the TBS certificate
* @throws IOException if extraction fails.
* @throws CertificateEncodingException if extraction fails.
*/
public static TBSCertificateStructure getTBSCertificateStructure(X509Certificate cert)
throws CertificateEncodingException, IOException {
DERObject obj = toDERObject(cert.getTBSCertificate());
return TBSCertificateStructure.getInstance(obj);
}
