source: other-projects/trunk/gs3-release-maker/tasks/sshtaskdef/src/mindbright/security/Cipher.java@ 14627

/******************************************************************************
 *
 * Copyright (c) 1998,99 by Mindbright Technology AB, Stockholm, Sweden.
 *                 www.mindbright.se, [email protected]
 *
 * 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.
 *
 *****************************************************************************
 * $Author: mats $
 * $Date: 1999/08/16 18:49:30 $
 * $Name: rel1-2-1 $
 *****************************************************************************/
package mindbright.security;

public abstract class Cipher {

  public static Cipher getInstance(String algorithm) {
    Class c;
    try {
      c = Class.forName("mindbright.security." + algorithm);
      return (Cipher)c.newInstance();
    } catch(Throwable t) {
      return null;
    }
  }

  public byte[] encrypt(byte[] src) { byte[] dest = new byte[src.length];
                                      encrypt(src, 0, dest, 0, src.length); 
                      return dest; }
  public abstract void encrypt(byte[] src, int srcOff, byte[] dest, int destOff, int len);
  public byte[] decrypt(byte[] src) { byte[] dest = new byte[src.length];
                                      decrypt(src, 0, dest, 0, src.length);
                                      return dest; }
  public abstract void decrypt(byte[] src, int srcOff, byte[] dest, int destOff, int len);
  public abstract void   setKey(byte[] key);

  public void setKey(String key) {
    MessageDigest md5;
    byte[] mdKey = new byte[32];
    try {
      md5 = MessageDigest.getInstance("MD5");
      md5.update(key.getBytes());
      byte[] digest = md5.digest();
      System.arraycopy(digest, 0, mdKey, 0, 16);
      System.arraycopy(digest, 0, mdKey, 16, 16);
    } catch(Exception e) {
      // !!!
      System.out.println("MD5 not implemented, can't generate key out of string!");
      System.exit(1);
    }
    setKey(mdKey);
  }

}