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.IOException;
import java.io.InputStream;
import java.io.OutputStream;

import org.bouncycastle.util.io.Streams;

class CMSProcessableInputStream implements CMSProcessable, CMSReadable
{
    private InputStream input;
    private boolean used = false;

    public CMSProcessableInputStream(
        InputStream input)
    {
        this.input = input;
    }

    public InputStream getInputStream()
    {
        checkSingleUsage();

        return input;
    }

    public void write(OutputStream zOut)
        throws IOException, CMSException
    {
        checkSingleUsage();

        Streams.pipeAll(input, zOut);
        input.close();
    }

    public Object getContent()
    {
        return getInputStream();
    }

    private synchronized void checkSingleUsage()
    {
        if (used)
        {
            throw new IllegalStateException("CMSProcessableInputStream can only be used once");
        }

        used = true;
    }
}