package gnu.crypto.jce.spec;

// --------------------------------------------------------------------------
// $Id: BlockCipherParameterSpec.java,v 1.2 2005/10/06 04:24:16 rsdio Exp $
//
// Copyright (C) 2002 Free Software Foundation, Inc.
//
// This file is part of GNU Crypto.
//
// GNU Crypto 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.
//
// GNU Crypto 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
//
// Linking this library statically or dynamically with other modules is
// making a combined work based on this library.  Thus, the terms and
// conditions of the GNU General Public License cover the whole
// combination.
//
// As a special exception, the copyright holders of this library give
// you permission to link this library with independent modules to
// produce an executable, regardless of the license terms of these
// independent modules, and to copy and distribute the resulting
// executable under terms of your choice, provided that you also meet,
// for each linked independent module, the terms and conditions of the
// license of that module.  An independent module is a module which is
// not derived from or based on this library.  If you modify this
// library, you may extend this exception to your version of the
// library, but you are not obligated to do so.  If you do not wish to
// do so, delete this exception statement from your version.
//
// --------------------------------------------------------------------------

import gnu.crypto.util.Util;

import java.security.spec.AlgorithmParameterSpec;

/**
 * Block cipher parameters in GNU Crypto are the cipher's name, its block
 * and key sizes, and an optional initialization vector.
 *
 * @version $Revision: 1.2 $
 */
public class BlockCipherParameterSpec implements AlgorithmParameterSpec {

   // Constants and variables.
   // -----------------------------------------------------------------------

   /**
    * The initialization vector.
    */
   protected byte[] iv;

   /**
    * The cipher's block size, in bytes.
    */
   protected int blockSize;

   /**
    * The cipher's key size, in bytes.
    */
   protected int keySize;

   // Constructors.
   // -----------------------------------------------------------------------

   /**
    * Create a new parameter specification.
    *
    * @param iv        The initialization vector, or <code>null</code> if
    *                  there is no IV.
    * @param blockSize The cipher's block size, in bytes.
    * @param keySize   The cipher's key size, in bytes.
    */
   public BlockCipherParameterSpec(byte[] iv, int blockSize, int keySize) {
      this.iv = (iv != null) ? (byte[]) iv.clone() : null;
      this.blockSize = blockSize;
      this.keySize = keySize;
   }

   /**
    * Create a new parameter specification with no IV.
    *
    * @param blockSize The cipher's block size, in bytes.
    * @param keySize   The cipher's key size, in bytes.
    */
   public
   BlockCipherParameterSpec(int blockSize, int keySize) {
      this(null, blockSize, keySize);
   }

   // Instance methods.
   // -----------------------------------------------------------------------

   /**
    * Get the initialization vector for the cipher, or <code>null</code>
    * if there is no IV.
    *
    * @return The IV.
    */
   public byte[] getIV() {
      return iv;
   }

   /**
    * Get the block size of the cipher these parameters are for.
    *
    * @return The block size.
    */
   public int getBlockSize() {
      return blockSize;
   }

   /**
    * Get the key size of the cipher these parameters are for.
    *
    * @return The block size.
    */
   public int getKeySize() {
      return keySize;
   }

   public String toString() {
      return getClass().getName() + " { " + 
         ((iv != null) ? ("IV=" + Util.toString(iv)) + ", " : "")
         + "BS=" + blockSize + ", KS=" + keySize + " }";
   }
}
