desencrypter.java

来自「java语言开发的P2P流媒体系统」· Java 代码 · 共 77 行

/* Stream-2-Stream - Peer to peer television and radio
 * Project homepage: http://s2s.sourceforge.net/
 * Copyright (C) 2005-2006 Jason Hooks
 * ---------------------------------------------------------------------------
 * 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., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
 * ---------------------------------------------------------------------------
 */
package stream2stream.XML;
import java.io.UnsupportedEncodingException;

import javax.crypto.*;
public class DesEncrypter {
	  Cipher ecipher;
      Cipher dcipher;
  
      public DesEncrypter(SecretKey key) {
          try {
              ecipher = Cipher.getInstance("DES");
              dcipher = Cipher.getInstance("DES");
              ecipher.init(Cipher.ENCRYPT_MODE, key);
              dcipher.init(Cipher.DECRYPT_MODE, key);
  
          } catch (javax.crypto.NoSuchPaddingException e) {
          } catch (java.security.NoSuchAlgorithmException e) {
          } catch (java.security.InvalidKeyException e) {System.out.println("invalid key");
          }
      }
  
      public String encrypt(String str) {
          try {
              // Encode the string into bytes using utf-8
              byte[] utf8 = str.getBytes("UTF8");
  
              // Encrypt
              byte[] enc = ecipher.doFinal(utf8);
  
              // Encode bytes to base64 to get a string
              return new sun.misc.BASE64Encoder().encode(enc);
          } catch (javax.crypto.BadPaddingException e) {
          } catch (IllegalBlockSizeException e) {
          } catch (UnsupportedEncodingException e) {
          } catch (java.io.IOException e) {
          }
          return null;
      }
  
      public String decrypt(String str) {
          try {
              // Decode base64 to get bytes
              byte[] dec = new sun.misc.BASE64Decoder().decodeBuffer(str);
  
              // Decrypt
              byte[] utf8 = dcipher.doFinal(dec);
  
              // Decode using utf-8
              return new String(utf8, "UTF8");
          } catch (javax.crypto.BadPaddingException e) {System.out.println("1");
          } catch (IllegalBlockSizeException e) {System.out.println("2");
          } catch (UnsupportedEncodingException e) {System.out.println("3");
          } catch (java.io.IOException e) {System.out.println("4");
          }
          return null;
      }
}