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.ess;

import org.bouncycastle.asn1.ASN1Object;
import org.bouncycastle.asn1.ASN1OctetString;
import org.bouncycastle.asn1.ASN1Primitive;
import org.bouncycastle.asn1.DEROctetString;

public class ContentIdentifier
    extends ASN1Object
{
     ASN1OctetString value;

    public static ContentIdentifier getInstance(Object o)
    {
        if (o instanceof ContentIdentifier)
        {
            return (ContentIdentifier) o;
        }
        else if (o != null)
        {
            return new ContentIdentifier(ASN1OctetString.getInstance(o));
        }

        return null;
    }

    
Create from OCTET STRING whose octets represent the identifier.

/**
     * Create from OCTET STRING whose octets represent the identifier.
     */
    private ContentIdentifier(
        ASN1OctetString value)
    {
        this.value = value;
    }

    
Create from byte array representing the identifier.

/**
     * Create from byte array representing the identifier.
     */
    public ContentIdentifier(
        byte[] value)
    {
        this(new DEROctetString(value));
    }
    
    public ASN1OctetString getValue()
    {
        return value;
    }

    
The definition of ContentIdentifier is

ContentIdentifier ::=  OCTET STRING


id-aa-contentIdentifier OBJECT IDENTIFIER ::= { iso(1)
 member-body(2) us(840) rsadsi(113549) pkcs(1) pkcs9(9)
 smime(16) id-aa(2) 7 }

/**
     * The definition of ContentIdentifier is
     * <pre>
     * ContentIdentifier ::=  OCTET STRING
     * </pre>
     * id-aa-contentIdentifier OBJECT IDENTIFIER ::= { iso(1)
     *  member-body(2) us(840) rsadsi(113549) pkcs(1) pkcs9(9)
     *  smime(16) id-aa(2) 7 }
     */
    public ASN1Primitive toASN1Primitive()
    {
        return value;
    }
}