http://www.bouncycastle.org/java.html: The Bouncy Castle Java APIs for CMS, PKCS, EAC, TSP, CMP, CRMF, OCSP, and certificate generation. This jar contains APIs for JDK 1.5 to JDK 1.8. The APIs can be used in conjunction with a JCE/JCA provider such as the one provided with the Bouncy Castle Cryptography APIs.
  • The Legion of the Bouncy Castle Inc. 
package org.bouncycastle.cms.bc;

import java.io.IOException;

import org.bouncycastle.asn1.x509.AlgorithmIdentifier;
import org.bouncycastle.cert.X509CertificateHolder;
import org.bouncycastle.crypto.params.AsymmetricKeyParameter;
import org.bouncycastle.operator.bc.BcRSAAsymmetricKeyWrapper;

public class BcRSAKeyTransRecipientInfoGenerator
    extends BcKeyTransRecipientInfoGenerator
{
    public BcRSAKeyTransRecipientInfoGenerator(byte[] subjectKeyIdentifier, AlgorithmIdentifier encAlgId, AsymmetricKeyParameter publicKey)
    {
        super(subjectKeyIdentifier, new BcRSAAsymmetricKeyWrapper(encAlgId, publicKey));
    }

    public BcRSAKeyTransRecipientInfoGenerator(X509CertificateHolder recipientCert)
        throws IOException
    {
        super(recipientCert, new BcRSAAsymmetricKeyWrapper(recipientCert.getSubjectPublicKeyInfo().getAlgorithm(), recipientCert.getSubjectPublicKeyInfo()));
    }
}