http://www.bouncycastle.org/java.html: The Bouncy Castle Crypto package is a Java implementation of cryptographic algorithms. This jar contains JCE provider and lightweight API for the Bouncy Castle Cryptography APIs for JDK 1.5 to JDK 1.7. 
package org.bouncycastle.asn1;

import java.io.OutputStream;

public abstract class ASN1Generator
{
    protected OutputStream _out;
    
    public ASN1Generator(OutputStream out)
    {
        _out = out;
    }
    
    public abstract OutputStream getRawOutputStream();
}