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 java.io.InputStream;

import org.bouncycastle.asn1.ASN1OctetStringParser;
import org.bouncycastle.asn1.ASN1SequenceParser;
import org.bouncycastle.asn1.BERTags;
import org.bouncycastle.asn1.cms.CompressedDataParser;
import org.bouncycastle.asn1.cms.ContentInfoParser;
import org.bouncycastle.operator.InputExpander;
import org.bouncycastle.operator.InputExpanderProvider;


Class for reading a CMS Compressed Data stream.

    CMSCompressedDataParser cp = new CMSCompressedDataParser(inputStream);
     
    process(cp.getContent(new ZlibExpanderProvider()).getContentStream());


 Note: this class does not introduce buffering - if you are processing large files you should create
 the parser with:
 
     CMSCompressedDataParser     ep = new CMSCompressedDataParser(new BufferedInputStream(inputStream, bufSize));
 

 where bufSize is a suitably large buffer size.

/**
 * Class for reading a CMS Compressed Data stream.
 * <pre>
 *     CMSCompressedDataParser cp = new CMSCompressedDataParser(inputStream);
 *      
 *     process(cp.getContent(new ZlibExpanderProvider()).getContentStream());
 * </pre>
 *  Note: this class does not introduce buffering - if you are processing large files you should create
 *  the parser with:
 *  <pre>
 *      CMSCompressedDataParser     ep = new CMSCompressedDataParser(new BufferedInputStream(inputStream, bufSize));
 *  </pre>
 *  where bufSize is a suitably large buffer size.
 */
public class CMSCompressedDataParser
    extends CMSContentInfoParser
{
    public CMSCompressedDataParser(
        byte[]    compressedData) 
        throws CMSException
    {
        this(new ByteArrayInputStream(compressedData));
    }

    public CMSCompressedDataParser(
        InputStream    compressedData) 
        throws CMSException
    {
        super(compressedData);
    }

    
Return a typed stream which will allow the reading of the compressed content in
expanded form.

Params:
  • expanderProvider – a provider of expander algorithm implementations.
Throws:
  • CMSException – if there is an exception parsing the CompressedData object.
Returns:a type stream which will yield the un-compressed content.
/**
     * Return a typed stream which will allow the reading of the compressed content in
     * expanded form.
     *
     * @param expanderProvider a provider of expander algorithm implementations.
     * @return a type stream which will yield the un-compressed content.
     * @throws CMSException if there is an exception parsing the CompressedData object.
     */
    public CMSTypedStream  getContent(InputExpanderProvider expanderProvider)
        throws CMSException
    {
        try
        {
            CompressedDataParser  comData = new CompressedDataParser((ASN1SequenceParser)_contentInfo.getContent(BERTags.SEQUENCE));
            ContentInfoParser     content = comData.getEncapContentInfo();
            InputExpander expander = expanderProvider.get(comData.getCompressionAlgorithmIdentifier());

            ASN1OctetStringParser bytes = (ASN1OctetStringParser)content.getContent(BERTags.OCTET_STRING);

            return new CMSTypedStream(content.getContentType().getId(), expander.getInputStream(bytes.getOctetStream()));
        }
        catch (IOException e)
        {
            throw new CMSException("IOException reading compressed content.", e);
        }
    }
}