desengine.java

这是linux下ssl vpn的实现程序

/*
 *  SSL-Explorer
 *
 *  Copyright (C) 2003-2006 3SP LTD. All Rights Reserved
 *
 *  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., 675 Mass Ave, Cambridge, MA 02139, USA.
 */
			
package com.maverick.crypto.engines;

import java.io.IOException;

/**
 * a class that provides a basic DES engine.
 */
public class DESEngine
    implements CipherEngine {
  protected static final int BLOCK_SIZE = 8;

  private int[] workingKey = null;

  /**
   * standard constructor.
   */
  public DESEngine() {
  }

  /**
   * initialise a DES cipher.
   *
   * @param forEncryption whether or not we are for encryption.
   * @param params the parameters required to set up the cipher.
   * @exception IllegalArgumentException if the params argument is
   * inappropriate.
   */
  public void init(
      boolean encrypting,
      byte[] key) {
    workingKey = generateWorkingKey(encrypting,
                                    key);

  }

  public String getAlgorithmName() {
    return "DES";
  }

  public byte[] doFinal(byte[] input) throws IOException {

      if(input.length % BLOCK_SIZE != 0)
          throw new IOException("Invalid block size on input data");

      byte[] output = new byte[input.length];
      for(int i=0;i<input.length;i+=BLOCK_SIZE)
          processBlock(input, i, output, i);

      return output;
  }

  public int getBlockSize() {
    return BLOCK_SIZE;
  }

  public int processBlock(
      byte[] in,
      int inOff,
      byte[] out,
      int outOff) throws IOException {
    if (workingKey == null) {
      throw new IllegalStateException("DES engine not initialised");
    }

    if ( (inOff + BLOCK_SIZE) > in.length) {
      throw new IOException("input buffer too short");
    }

    if ( (outOff + BLOCK_SIZE) > out.length) {
      throw new IOException("output buffer too short");
    }

    desFunc(workingKey, in, inOff, out, outOff);

    return BLOCK_SIZE;
  }

  public void reset() {
  }

  /**
   * what follows is mainly taken from "Applied Cryptography", by
   * Bruce Schneier, however it also bears great resemblance to Richard
   * Outerbridge's D3DES...
   */

  static short[] Df_Key = {
      0x01, 0x23, 0x45, 0x67, 0x89, 0xab, 0xcd, 0xef,
      0xfe, 0xdc, 0xba, 0x98, 0x76, 0x54, 0x32, 0x10,
      0x89, 0xab, 0xcd, 0xef, 0x01, 0x23, 0x45, 0x67
  };

  static short[] bytebit = {
      0200, 0100, 040, 020, 010, 04, 02, 01
  };

  static int[] bigbyte = {
      0x800000, 0x400000, 0x200000, 0x100000,
      0x80000, 0x40000, 0x20000, 0x10000,
      0x8000, 0x4000, 0x2000, 0x1000,
      0x800, 0x400, 0x200, 0x100,
      0x80, 0x40, 0x20, 0x10,
      0x8, 0x4, 0x2, 0x1
  };

  /*
   * Use the key schedule specified in the Standard (ANSI X3.92-1981).
   */

  static byte[] pc1 = {
      56, 48, 40, 32, 24, 16, 8, 0, 57, 49, 41, 33, 25, 17,
      9, 1, 58, 50, 42, 34, 26, 18, 10, 2, 59, 51, 43, 35,
      62, 54, 46, 38, 30, 22, 14, 6, 61, 53, 45, 37, 29, 21,
      13, 5, 60, 52, 44, 36, 28, 20, 12, 4, 27, 19, 11, 3
  };

  static byte[] totrot = {
      1, 2, 4, 6, 8, 10, 12, 14,
      15, 17, 19, 21, 23, 25, 27, 28
  };

  static byte[] pc2 = {
      13, 16, 10, 23, 0, 4, 2, 27, 14, 5, 20, 9,
      22, 18, 11, 3, 25, 7, 15, 6, 26, 19, 12, 1,
      40, 51, 30, 36, 46, 54, 29, 39, 50, 44, 32, 47,
      43, 48, 38, 55, 33, 52, 45, 41, 49, 35, 28, 31
  };

  static int[] SP1 = {
      0x01010400, 0x00000000, 0x00010000, 0x01010404,
      0x01010004, 0x00010404, 0x00000004, 0x00010000,
      0x00000400, 0x01010400, 0x01010404, 0x00000400,
      0x01000404, 0x01010004, 0x01000000, 0x00000004,
      0x00000404, 0x01000400, 0x01000400, 0x00010400,
      0x00010400, 0x01010000, 0x01010000, 0x01000404,
      0x00010004, 0x01000004, 0x01000004, 0x00010004,
      0x00000000, 0x00000404, 0x00010404, 0x01000000,
      0x00010000, 0x01010404, 0x00000004, 0x01010000,
      0x01010400, 0x01000000, 0x01000000, 0x00000400,
      0x01010004, 0x00010000, 0x00010400, 0x01000004,
      0x00000400, 0x00000004, 0x01000404, 0x00010404,
      0x01010404, 0x00010004, 0x01010000, 0x01000404,
      0x01000004, 0x00000404, 0x00010404, 0x01010400,
      0x00000404, 0x01000400, 0x01000400, 0x00000000,
      0x00010004, 0x00010400, 0x00000000, 0x01010004
  };

  static int[] SP2 = {
      0x80108020, 0x80008000, 0x00008000, 0x00108020,
      0x00100000, 0x00000020, 0x80100020, 0x80008020,
      0x80000020, 0x80108020, 0x80108000, 0x80000000,
      0x80008000, 0x00100000, 0x00000020, 0x80100020,
      0x00108000, 0x00100020, 0x80008020, 0x00000000,
      0x80000000, 0x00008000, 0x00108020, 0x80100000,
      0x00100020, 0x80000020, 0x00000000, 0x00108000,
      0x00008020, 0x80108000, 0x80100000, 0x00008020,
      0x00000000, 0x00108020, 0x80100020, 0x00100000,
      0x80008020, 0x80100000, 0x80108000, 0x00008000,
      0x80100000, 0x80008000, 0x00000020, 0x80108020,
      0x00108020, 0x00000020, 0x00008000, 0x80000000,
      0x00008020, 0x80108000, 0x00100000, 0x80000020,
      0x00100020, 0x80008020, 0x80000020, 0x00100020,
      0x00108000, 0x00000000, 0x80008000, 0x00008020,
      0x80000000, 0x80100020, 0x80108020, 0x00108000
  };

  static int[] SP3 = {
      0x00000208, 0x08020200, 0x00000000, 0x08020008,
      0x08000200, 0x00000000, 0x00020208, 0x08000200,
      0x00020008, 0x08000008, 0x08000008, 0x00020000,
      0x08020208, 0x00020008, 0x08020000, 0x00000208,
      0x08000000, 0x00000008, 0x08020200, 0x00000200,
      0x00020200, 0x08020000, 0x08020008, 0x00020208,
      0x08000208, 0x00020200, 0x00020000, 0x08000208,
      0x00000008, 0x08020208, 0x00000200, 0x08000000,
      0x08020200, 0x08000000, 0x00020008, 0x00000208,
      0x00020000, 0x08020200, 0x08000200, 0x00000000,
      0x00000200, 0x00020008, 0x08020208, 0x08000200,
      0x08000008, 0x00000200, 0x00000000, 0x08020008,
      0x08000208, 0x00020000, 0x08000000, 0x08020208,
      0x00000008, 0x00020208, 0x00020200, 0x08000008,
      0x08020000, 0x08000208, 0x00000208, 0x08020000,
      0x00020208, 0x00000008, 0x08020008, 0x00020200
  };

  static int[] SP4 = {
      0x00802001, 0x00002081, 0x00002081, 0x00000080,
      0x00802080, 0x00800081, 0x00800001, 0x00002001,
      0x00000000, 0x00802000, 0x00802000, 0x00802081,
      0x00000081, 0x00000000, 0x00800080, 0x00800001,
      0x00000001, 0x00002000, 0x00800000, 0x00802001,
      0x00000080, 0x00800000, 0x00002001, 0x00002080,
      0x00800081, 0x00000001, 0x00002080, 0x00800080,
      0x00002000, 0x00802080, 0x00802081, 0x00000081,
      0x00800080, 0x00800001, 0x00802000, 0x00802081,
      0x00000081, 0x00000000, 0x00000000, 0x00802000,
      0x00002080, 0x00800080, 0x00800081, 0x00000001,
      0x00802001, 0x00002081, 0x00002081, 0x00000080,
      0x00802081, 0x00000081, 0x00000001, 0x00002000,
      0x00800001, 0x00002001, 0x00802080, 0x00800081,
      0x00002001, 0x00002080, 0x00800000, 0x00802001,
      0x00000080, 0x00800000, 0x00002000, 0x00802080
  };

  static int[] SP5 = {
      0x00000100, 0x02080100, 0x02080000, 0x42000100,
      0x00080000, 0x00000100, 0x40000000, 0x02080000,
      0x40080100, 0x00080000, 0x02000100, 0x40080100,
      0x42000100, 0x42080000, 0x00080100, 0x40000000,
      0x02000000, 0x40080000, 0x40080000, 0x00000000,
      0x40000100, 0x42080100, 0x42080100, 0x02000100,
      0x42080000, 0x40000100, 0x00000000, 0x42000000,
      0x02080100, 0x02000000, 0x42000000, 0x00080100,
      0x00080000, 0x42000100, 0x00000100, 0x02000000,
      0x40000000, 0x02080000, 0x42000100, 0x40080100,
      0x02000100, 0x40000000, 0x42080000, 0x02080100,
      0x40080100, 0x00000100, 0x02000000, 0x42080000,
      0x42080100, 0x00080100, 0x42000000, 0x42080100,
      0x02080000, 0x00000000, 0x40080000, 0x42000000,
      0x00080100, 0x02000100, 0x40000100, 0x00080000,
      0x00000000, 0x40080000, 0x02080100, 0x40000100