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.ByteArrayOutputStream;
import java.io.IOException;
import java.io.OutputStream;

import org.bouncycastle.asn1.ASN1OctetString;
import org.bouncycastle.asn1.BEROctetString;
import org.bouncycastle.asn1.cms.CMSObjectIdentifiers;
import org.bouncycastle.asn1.cms.CompressedData;
import org.bouncycastle.asn1.cms.ContentInfo;
import org.bouncycastle.asn1.x509.AlgorithmIdentifier;
import org.bouncycastle.operator.OutputCompressor;


General class for generating a compressed CMS message.


A simple example of usage.



     CMSCompressedDataGenerator  fact = new CMSCompressedDataGenerator();
     CMSCompressedData           data = fact.generate(content, new ZlibCompressor());



/**
 * General class for generating a compressed CMS message.
 * <p>
 * A simple example of usage.
 * <p>
 * <pre>
 *      CMSCompressedDataGenerator  fact = new CMSCompressedDataGenerator();
 *
 *      CMSCompressedData           data = fact.generate(content, new ZlibCompressor());
 * </pre>
 */
public class CMSCompressedDataGenerator
{
    public static final String  ZLIB    = "1.2.840.113549.1.9.16.3.8";

    
base constructor

/**
     * base constructor
     */
    public CMSCompressedDataGenerator()
    {
    }

    
generate an object that contains an CMS Compressed Data

/**
     * generate an object that contains an CMS Compressed Data
     */
    public CMSCompressedData generate(
        CMSTypedData content,
        OutputCompressor compressor)
        throws CMSException
    {
        AlgorithmIdentifier     comAlgId;
        ASN1OctetString         comOcts;

        try
        {
            ByteArrayOutputStream bOut = new ByteArrayOutputStream();
            OutputStream zOut = compressor.getOutputStream(bOut);

            content.write(zOut);

            zOut.close();

            comAlgId = compressor.getAlgorithmIdentifier();
            comOcts = new BEROctetString(bOut.toByteArray());
        }
        catch (IOException e)
        {
            throw new CMSException("exception encoding data.", e);
        }

        ContentInfo     comContent = new ContentInfo(
                                    content.getContentType(), comOcts);

        ContentInfo     contentInfo = new ContentInfo(
                                    CMSObjectIdentifiers.compressedData,
                                    new CompressedData(comAlgId, comContent));

        return new CMSCompressedData(contentInfo);
    }
}