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;

import java.util.HashSet;
import java.util.Set;

import org.bouncycastle.asn1.DERNull;
import org.bouncycastle.asn1.oiw.OIWObjectIdentifiers;
import org.bouncycastle.asn1.pkcs.PKCSObjectIdentifiers;
import org.bouncycastle.asn1.teletrust.TeleTrusTObjectIdentifiers;
import org.bouncycastle.asn1.x509.AlgorithmIdentifier;

public class DefaultCMSSignatureEncryptionAlgorithmFinder
    implements CMSSignatureEncryptionAlgorithmFinder
{
    private static final Set RSA_PKCS1d5 = new HashSet();

    static
    {
        RSA_PKCS1d5.add(PKCSObjectIdentifiers.md2WithRSAEncryption);
        RSA_PKCS1d5.add(PKCSObjectIdentifiers.md4WithRSAEncryption);
        RSA_PKCS1d5.add(PKCSObjectIdentifiers.md5WithRSAEncryption);
        RSA_PKCS1d5.add(PKCSObjectIdentifiers.sha1WithRSAEncryption);
        RSA_PKCS1d5.add(OIWObjectIdentifiers.md4WithRSAEncryption);
        RSA_PKCS1d5.add(OIWObjectIdentifiers.md4WithRSA);
        RSA_PKCS1d5.add(OIWObjectIdentifiers.md5WithRSA);
        RSA_PKCS1d5.add(OIWObjectIdentifiers.sha1WithRSA);
        RSA_PKCS1d5.add(TeleTrusTObjectIdentifiers.rsaSignatureWithripemd128);
        RSA_PKCS1d5.add(TeleTrusTObjectIdentifiers.rsaSignatureWithripemd160);
        RSA_PKCS1d5.add(TeleTrusTObjectIdentifiers.rsaSignatureWithripemd256);
    }

    public AlgorithmIdentifier findEncryptionAlgorithm(AlgorithmIdentifier signatureAlgorithm)
    {
               // RFC3370 section 3.2 with RFC 5754 update
        if (RSA_PKCS1d5.contains(signatureAlgorithm.getAlgorithm()))
        {
            return new AlgorithmIdentifier(PKCSObjectIdentifiers.rsaEncryption, DERNull.INSTANCE);
        }

        return signatureAlgorithm;
    }
}