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 1.8.
  • The Legion of the Bouncy Castle Inc. 
package org.bouncycastle.asn1.pkcs;

import org.bouncycastle.asn1.ASN1Encodable;
import org.bouncycastle.asn1.ASN1EncodableVector;
import org.bouncycastle.asn1.ASN1Object;
import org.bouncycastle.asn1.ASN1ObjectIdentifier;
import org.bouncycastle.asn1.ASN1Primitive;
import org.bouncycastle.asn1.ASN1Sequence;
import org.bouncycastle.asn1.ASN1Set;
import org.bouncycastle.asn1.ASN1TaggedObject;
import org.bouncycastle.asn1.DLSequence;
import org.bouncycastle.asn1.DLTaggedObject;

public class SafeBag
    extends ASN1Object
{
    private ASN1ObjectIdentifier bagId;
    private ASN1Encodable bagValue;
    private ASN1Set                     bagAttributes;

    public SafeBag(
        ASN1ObjectIdentifier oid,
        ASN1Encodable obj)
    {
        this.bagId = oid;
        this.bagValue = obj;
        this.bagAttributes = null;
    }

    public SafeBag(
        ASN1ObjectIdentifier oid,
        ASN1Encodable obj,
        ASN1Set                 bagAttributes)
    {
        this.bagId = oid;
        this.bagValue = obj;
        this.bagAttributes = bagAttributes;
    }

    public static SafeBag getInstance(
        Object  obj)
    {
        if (obj instanceof SafeBag)
        {
            return (SafeBag)obj;
        }

        if (obj != null)
        {
            return new SafeBag(ASN1Sequence.getInstance(obj));
        }

        return null;
    }

    private SafeBag(
        ASN1Sequence    seq)
    {
        this.bagId = (ASN1ObjectIdentifier)seq.getObjectAt(0);
        this.bagValue = ((ASN1TaggedObject)seq.getObjectAt(1)).getObject();
        if (seq.size() == 3)
        {
            this.bagAttributes = (ASN1Set)seq.getObjectAt(2);
        }
    }

    public ASN1ObjectIdentifier getBagId()
    {
        return bagId;
    }

    public ASN1Encodable getBagValue()
    {
        return bagValue;
    }

    public ASN1Set getBagAttributes()
    {
        return bagAttributes;
    }

    public ASN1Primitive toASN1Primitive()
    {
        ASN1EncodableVector v = new ASN1EncodableVector();

        v.add(bagId);
        v.add(new DLTaggedObject(true, 0, bagValue));

        if (bagAttributes != null)
        {
            v.add(bagAttributes);
        }

        return new DLSequence(v);
    }
}