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 java.io.OutputStream;

import org.bouncycastle.asn1.ASN1ObjectIdentifier;
import org.bouncycastle.asn1.cms.CMSObjectIdentifiers;
import org.bouncycastle.util.Arrays;


a holding class for a byte array of data to be processed.

/**
 * a holding class for a byte array of data to be processed.
 */
public class CMSProcessableByteArray
    implements CMSTypedData, CMSReadable
{
    private final ASN1ObjectIdentifier type;
    private final byte[]  bytes;

    public CMSProcessableByteArray(
        byte[]  bytes)
    {
        this(CMSObjectIdentifiers.data, bytes);
    }

    public CMSProcessableByteArray(
        ASN1ObjectIdentifier type,
        byte[]  bytes)
    {
        this.type = type;
        this.bytes = bytes;
    }

    public InputStream getInputStream()
    {
        return new ByteArrayInputStream(bytes);
    }

    public void write(OutputStream zOut)
        throws IOException, CMSException
    {
        zOut.write(bytes);
    }

    public Object getContent()
    {
        return Arrays.clone(bytes);
    }

    public ASN1ObjectIdentifier getContentType()
    {
        return type;
    }
}