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.io.ByteArrayInputStream;
import java.io.IOException;

import org.bouncycastle.asn1.cms.ContentInfo;
import org.bouncycastle.asn1.cms.EncryptedContentInfo;
import org.bouncycastle.asn1.cms.EncryptedData;
import org.bouncycastle.operator.InputDecryptor;
import org.bouncycastle.operator.InputDecryptorProvider;

public class CMSEncryptedData
{
    private ContentInfo contentInfo;
    private EncryptedData encryptedData;

    public CMSEncryptedData(ContentInfo contentInfo)
    {
        this.contentInfo = contentInfo;

        this.encryptedData = EncryptedData.getInstance(contentInfo.getContent());
    }

    public byte[] getContent(InputDecryptorProvider inputDecryptorProvider)
        throws CMSException
    {
        try
        {
            return CMSUtils.streamToByteArray(getContentStream(inputDecryptorProvider).getContentStream());
        }
        catch (IOException e)
        {
            throw new CMSException("unable to parse internal stream: " + e.getMessage(), e);
        }
    }

    public CMSTypedStream getContentStream(InputDecryptorProvider inputDecryptorProvider)
        throws CMSException
    {
        try
        {
            EncryptedContentInfo encContentInfo = encryptedData.getEncryptedContentInfo();
            InputDecryptor decrytor = inputDecryptorProvider.get(encContentInfo.getContentEncryptionAlgorithm());

            ByteArrayInputStream encIn = new ByteArrayInputStream(encContentInfo.getEncryptedContent().getOctets());

            return new CMSTypedStream(encContentInfo.getContentType(), decrytor.getInputStream(encIn));
        }
        catch (Exception e)
        {
            throw new CMSException("unable to create stream: " + e.getMessage(), e);
        }
    }

    
return the ContentInfo

/**
     * return the ContentInfo
     */
    public ContentInfo toASN1Structure()
    {
        return contentInfo;
    }
}