DER.java

/*
 * Copyright (C) 2006-2008 Alfresco Software Limited.
 *
 * This program is free software; you can redistribute it and/or
 * modify it under the terms of the GNU General Public License
 * as published by the Free Software Foundation; either version 2
 * of the License, or (at your option) any later version.

 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.

 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.

 * As a special exception to the terms and conditions of version 2.0 of 
 * the GPL, you may redistribute this Program in connection with Free/Libre 
 * and Open Source Software ("FLOSS") applications as described in Alfresco's 
 * FLOSS exception.  You should have recieved a copy of the text describing 
 * the FLOSS exception, and it is also available here: 
 * http://www.alfresco.com/legal/licensing"
 */

package org.alfresco.jlan.server.auth.asn;

/**
 * DER Class
 * 
 * <p>Contains constants for ASN.1 DER encoding.
 *
 * @author gkspencer
 */
public class DER {
  
  // Object types
  
  public static final int Boolean             = 0x01;
  public static final int Integer             = 0x02;
  public static final int BitString           = 0x03;
  public static final int OctetString         = 0x04;
  public static final int Null                = 0x05;
  public static final int ObjectIdentifier    = 0x06;
  public static final int External            = 0x08;
  public static final int Enumerated          = 0x0A;
  public static final int UTF8String          = 0x0C;
  public static final int Sequence            = 0x10;
  public static final int NumericString       = 0x12;
  public static final int PrintableString     = 0x13;
  public static final int GeneralizedTime     = 0x18;
  public static final int GeneralString       = 0x1B;
  public static final int UniversalString     = 0x1C;

  // Type mask
  
  public static final int TypeMask            = 0x1F;
  
  // Tag class
  
  public static final int Universal           = 0x00;
  public static final int Application         = 0x40;
  public static final int ContextSpecific     = 0x80;
  public static final int Private             = 0xC0;
  
  public static final int Constructed         = 0x20;
  public static final int Tagged              = 0x80;
  
  /**
   * Return the type field
   * 
   * @param typ int
   * @return int
   */
  public static final int isType(int typ) {
    return typ & TypeMask;
  }
  
  /**
   * Check if a type is constructed
   * 
   * @param typ int
   * @return boolean
   */
  public final static boolean isConstructed(int typ) {
    return ( typ & Constructed) != 0 ? true : false;
  }
  
  /**
   * Check if a type is tagged
   * 
   * @param typ int
   * @return boolean
   */
  public final static boolean isTagged(int typ) {
    return ( typ & Tagged) != 0 ? true : false;
  }

  /**
   * Check for context specific flag
   * 
   * @param typ int
   * @return boolean
   */
  public final static boolean isContextSpecific(int typ) {
    return ( typ & ContextSpecific) != 0 ? true : false;
  }

  /**
   * Check for the application flag
   * 
   * @param typ int
   * @return boolean
   */
  public final static boolean isApplicationSpecific(int typ) {
    return ( typ & Application) != 0 ? true : false;
  }
  
  /**
   * Return the type as a string
   * 
   * @param typ int
   * @return String
   */
  public final static String isTypeString(int typ) {
	  String typStr = null;
	  
	  switch ( typ) {
		  case Boolean:
			  typStr = "Boolean";
			  break;
		  case Integer:
			  typStr = "Integer";
			  break;
		  case BitString:
			  typStr = "BitString";
			  break;
		  case OctetString:
			  typStr = "OctetString";
			  break;
		  case Null:
			  typStr = "Null";
			  break;
		  case ObjectIdentifier:
			  typStr = "ObjectIdentifier";
			  break;
		  case External:
			  typStr = "External";
			  break;
		  case Enumerated:
			  typStr = "Enumerated";
			  break;
		  case UTF8String:
			  typStr = "UTF8String";
			  break;
		  case Sequence:
			  typStr = "Sequence";
			  break;
		  case NumericString:
			  typStr = "NumericString";
			  break;
		  case PrintableString:
			  typStr = "PrintableString";
			  break;
		  case GeneralizedTime:
			  typStr = "GeneralizedTime";
			  break;
		  case GeneralString:
			  typStr = "GeneralString";
			  break;
		  case UniversalString:
			  typStr = "UniversalString";
			  break;
		  default:
			  typStr = "UnknownType (" + typ + ")";
		  	  break;
	  }
	  
	  return typStr;
  }
}