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NessieHashTVEmitter.java

package gnu.crypto.tool;

// ----------------------------------------------------------------------------
// $Id: NessieHashTVEmitter.java,v 1.3 2002/11/07 17:17:46 raif Exp $
//
// Copyright (C) 2001, 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, 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; see the file COPYING.  If not, write to the
//
//    Free Software Foundation Inc.,
//    59 Temple Place - Suite 330,
//    Boston, MA 02111-1307
//    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.hash.HashFactory;
import gnu.crypto.hash.IMessageDigest;
import gnu.crypto.util.Util;

/**
 * A utility class to generate NESSIE test vectors for a designated hash
 * algorithm.<p>
 *
 * <b>NOTE</b>: The <i>test3</i> test vector will be generated iff the global
 * system environment variable named "TORTURE" is set. It is skipped otherwise.
 *
 * @version $Revision: 1.3 $
 */
00059 public class NessieHashTVEmitter {

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

   // Constructor(s)
   // -------------------------------------------------------------------------

   /** Trivial 0-arguments constructor to enforce Singleton pattern. */
00068    private NessieHashTVEmitter() {
      super();
   }

   // Class methods
   // -------------------------------------------------------------------------

   public static final void main(String[] args) {
      try {
         IMessageDigest md = HashFactory.getInstance(args[0]);

         long time = -System.currentTimeMillis();

         test1(md);
         test2(md);
         test3(md);

         time += System.currentTimeMillis();
         System.out.println();
         System.out.println("End of test vectors");
         System.out.println();
         System.out.println("*** Tests lasted "+time+" ms...");

      } catch (Exception x) {
         x.printStackTrace(System.err);
      }
   }

   private static void test1(IMessageDigest md) {
      byte[] data = new byte[128];
      byte[] result;

      System.out.println("Message digests of strings of 0-bits and length L:");
      for (int i = 0; i < 128; i++) {
         System.out.print("    L = ");
         String s = "    "+String.valueOf(8*i);
         System.out.print(s.substring(s.length()-4));
         System.out.print(": ");
         md.update(data, 0, i);
         result = md.digest();
         System.out.println(Util.toString(result));
      }
   }

   private static void test2(IMessageDigest md) {
      int bl = md.hashSize();
      byte[] data = new byte[bl];
      byte[] result;

      System.out.println("Message digests of all "+(String.valueOf(8*bl))
         +"-bit strings S containing a single 1-bit:");
      for (int i = 0; i < bl; i++)
         for (int j = 0; j < 8; j++) {
            data[i] = (byte)(1 << (7-j));
            System.out.print("    S = "+Util.toString(data)+": ");
            md.update(data, 0, bl);
            result = md.digest();
            System.out.println(Util.toString(result));
            data[i] = 0x00;
         }
   }

   private static void test3(IMessageDigest md) {
      // this is torture for low-speed CPUs. only execute if global env var
      // TORTURE is set!
      String dummy = System.getProperty("TORTURE");
      if (dummy == null) {
         return;
      }

      int bl = md.hashSize();
      byte[] data = new byte[bl];
      int limit = 100000000;

      System.out.print("Iterated message digest computation ("
         +String.valueOf(limit)+" times): ");
      for (int i = 0; i < limit; i++) {
         md.update(data, 0, bl);
         data = md.digest();
      }

      System.out.println(Util.toString(data));
   }
}

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