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. 
package org.bouncycastle.asn1;

import java.io.InputStream;

public interface ASN1OctetStringParser
    extends DEREncodable, InMemoryRepresentable
{
    public InputStream getOctetStream();
}