package gnu.crypto.jce.spec;

// --------------------------------------------------------------------------
// $Id: TMMHParameterSpec.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
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// 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
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// 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.prng.IRandom;

import java.security.spec.AlgorithmParameterSpec;

/**
 * This class represents the algorithm parameters for the Truncated
 * Multi-Modular Hash function for use with JCE-derived instances of
 * {@link gnu.crypto.mac.TMMH16}.
 *
 * <p>This class is little more than a container for the key stream, tag
 * length, and prefix parameters for the TMMH algorithm.
 *
 * @version $Revision: 1.2 $
 */
public class TMMHParameterSpec implements AlgorithmParameterSpec {

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

   /** The keystream. */
   protected IRandom keystream;

   /** The tag length. */
   protected Integer tagLength;

   /** The prefix. */
   protected byte[] prefix;

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

   /**
    * Create a new parameter specification.
    *
    * @param keystream The (PRNG) key stream.
    * @param tagLength The tag length.
    * @param prefix    The prefix.
    */
   public
   TMMHParameterSpec(IRandom keystream, Integer tagLength, byte[] prefix) {
      this.keystream = keystream;
      this.tagLength = tagLength;
      this.prefix = prefix;
   }

   /**
    * Create a new parameter specification with no prefix.
    *
    * @param keystream The (PRNG) key stream.
    * @param tagLength The tag length.
    */
   public TMMHParameterSpec(IRandom keystream, Integer tagLength) {
      this(keystream, tagLength, null);
   }

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

   /**
    * Return the key stream this specification was initialized with.
    *
    * @return The key stream.
    */
   public IRandom getKeystream() {
      return keystream;
   }

   /**
    * Return the tag length this specification was initialized with.
    *
    * @return The tag length.
    */
   public Integer getTagLength() {
      return tagLength;
   }

   /**
    * Return the prefix, or <code>null</code> if no prefix was
    * specified.
    *
    * @return The prefix.
    */
   public byte[] getPrefix() {
      return prefix;
   }
}
