10.23

[实验任务一]：加密算法

目前常用的加密算法有DES（Data Encryption Standard）和IDEA（International Data Encryption Algorithm）国际数据加密算法等，请用工厂方法实现加密算法系统。

实验要求：

1. 画出对应的类图；

 

 

 

2. 提交该系统的代码，该系统务必是一个可以能够直接使用的系统，查阅资料完成相应加密算法的实现；

package org.example;

/*
* Copyright 2001-2005 The Apache Software Foundation.
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
*      http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/

import java.io.IOException;
import javax.portlet.PortletConfig;
import javax.portlet.GenericPortlet;
import javax.portlet.PortletException;
import javax.portlet.PortletRequestDispatcher;
import javax.portlet.RenderRequest;
import javax.portlet.RenderResponse;
import javax.portlet.WindowState;

public class MyPortlet extends GenericPortlet {

   private static final String NORMAL_VIEW = "/normal.jsp";
   private static final String MAXIMIZED_VIEW = "/maximized.jsp";
   private static final String HELP_VIEW = "/help.jsp";

   private PortletRequestDispatcher normalView;
   private PortletRequestDispatcher maximizedView;
   private PortletRequestDispatcher helpView;

   public void doView( RenderRequest request, RenderResponse response )
       throws PortletException, IOException {

       if( WindowState.MINIMIZED.equals( request.getWindowState() ) ) {
           return;
       }

       if ( WindowState.NORMAL.equals( request.getWindowState() ) ) {
           normalView.include( request, response );
       } else {
           maximizedView.include( request, response );
       }
   }

   protected void doHelp( RenderRequest request, RenderResponse response )
       throws PortletException, IOException {

       helpView.include( request, response );

   }

   public void init( PortletConfig config ) throws PortletException {
       super.init( config );
       normalView = config.getPortletContext().getRequestDispatcher( NORMAL_VIEW );
       maximizedView = config.getPortletContext().getRequestDispatcher( MAXIMIZED_VIEW );
       helpView = config.getPortletContext().getRequestDispatcher( HELP_VIEW );
   }

   public void destroy() {
       normalView = null;
       maximizedView = null;
       helpView = null;
       super.destroy();
   }

}

import javax.crypto.Cipher;

import javax.crypto.KeyGenerator;

import javax.crypto.SecretKey;

 

 

public class DES  implements Method {

 

    public  void work(String str,String password,String codeStringBegin) {

        String codeStringEnd=null;             //加密后的密文

        String decodeString=null;  //密文解密后得到的明文

        System.out.println("要加密的明文:20223867 尹丹彤"+codeStringBegin);

        String cipherType = "DESede"; //加密算法类型，可设置为DES、DESede、AES等字符串

        try

        {

            //获取密钥生成器

            KeyGenerator keyGen=KeyGenerator.getInstance(cipherType);

            //初始化密钥生成器，不同的加密算法其密钥长度可能不同

            keyGen.init(112);

            //生成密钥

            SecretKey key=keyGen.generateKey();

 

            //得到密钥字节码

            byte[] keyByte=key.getEncoded();

            //输出密钥的字节码

            System.out.println("密钥是：");

            for(int i=0;i<keyByte.length;i++)

            {

                System.out.print(keyByte[i]+",");

            }

            System.out.println("");

            //创建密码器

            Cipher cp=Cipher.getInstance(cipherType);

            //初始化密码器

            cp.init(Cipher.ENCRYPT_MODE,key);

            System.out.println("要加密的字符串是："+ codeStringBegin);

            byte[] codeStringByte=codeStringBegin.getBytes("UTF8");

            System.out.println("要加密的字符串对应的字节码是：");

            for(int i=0;i<codeStringByte.length;i++)

            {

                System.out.print(codeStringByte[i]+",");

            }

            System.out.println("");

            //开始加密

            byte[] codeStringByteEnd=cp.doFinal(codeStringByte);

            System.out.println("加密后的字符串对应的字节码是：");

            for(int i=0;i<codeStringByteEnd.length;i++)

            {

                System.out.print(codeStringByteEnd[i]+",");

            }

            System.out.println("");

            codeStringEnd=new String(codeStringByteEnd);

            System.out.println("加密后的字符串是：" + codeStringEnd);

            System.out.println("");

            //重新初始化密码器

            cp.init(Cipher.DECRYPT_MODE,key);

            //开始解密

            byte[] decodeStringByteEnd=cp.doFinal(codeStringByteEnd);

            System.out.println("解密后的字符串对应的字节码是：");

            for(int i=0;i<decodeStringByteEnd.length;i++)

            {

                System.out.print(decodeStringByteEnd[i]+",");

            }

            System.out.println("");

            decodeString=new String(decodeStringByteEnd);

            System.out.println("解密后的字符串是：" + decodeString);

            System.out.println("");

        }

        catch(Exception e)

        {

            e.printStackTrace();

        }

    }

 

 

}

import javax.crypto.Cipher;

import javax.crypto.KeyGenerator;

import javax.crypto.SecretKey;

import org.apache.commons.codec.binary.Base64;

import org.bouncycastle.jce.provider.BouncyCastleProvider;

 

import javax.crypto.Cipher;

import javax.crypto.KeyGenerator;

import javax.crypto.SecretKey;

import javax.crypto.spec.SecretKeySpec;

import java.security.Key;

import java.security.Security;

 

 

public class IDEA implements Method{

 

    public static final String KEY_ALGORITHM="IDEA";

 

    public static final String CIPHER_ALGORITHM="IDEA/ECB/ISO10126Padding";

    public static byte[] initkey() throws Exception{

        //加入bouncyCastle支持

        Security.addProvider(new BouncyCastleProvider());

 

        //实例化密钥生成器

        KeyGenerator kg=KeyGenerator.getInstance(KEY_ALGORITHM);

        //初始化密钥生成器，IDEA要求密钥长度为128位

        kg.init(128);

        //生成密钥

        SecretKey secretKey=kg.generateKey();

        //获取二进制密钥编码形式

        return secretKey.getEncoded();

    }

    /**

     * 转换密钥

     * @param key 二进制密钥

     * @return Key 密钥

     * */

    private static Key toKey(byte[] key) throws Exception{

        //实例化DES密钥

        //生成密钥

        SecretKey secretKey=new SecretKeySpec(key,KEY_ALGORITHM);

        return secretKey;

    }

 

    /**

     * 加密数据

     * @param data 待加密数据

     * @param key 密钥

     * @return byte[] 加密后的数据

     * */

    private static byte[] encrypt(byte[] data,byte[] key) throws Exception{

        //加入bouncyCastle支持

        Security.addProvider(new BouncyCastleProvider());

        //还原密钥

        Key k=toKey(key);

        //实例化

        Cipher cipher=Cipher.getInstance(CIPHER_ALGORITHM);

        //初始化，设置为加密模式

        cipher.init(Cipher.ENCRYPT_MODE, k);

        //执行操作

        return cipher.doFinal(data);

    }

    /**

     * 解密数据

     * @param data 待解密数据

     * @param key 密钥

     * @return byte[] 解密后的数据

     * */

    private static byte[] decrypt(byte[] data,byte[] key) throws Exception{

        //加入bouncyCastle支持

        Security.addProvider(new BouncyCastleProvider());

        //还原密钥

        Key k =toKey(key);

        Cipher cipher=Cipher.getInstance(CIPHER_ALGORITHM);

        //初始化，设置为解密模式

        cipher.init(Cipher.DECRYPT_MODE, k);

        //执行操作

        return cipher.doFinal(data);

    }

    public static String getKey(){

        String result = null;

        try {

            result = Base64.encodeBase64String(initkey());

        } catch (Exception e) {

            e.printStackTrace();

        }

        return result;

    }

    public static String ideaEncrypt(String data, String key) {

        String result = null;

        try {

            byte[] data_en = encrypt(data.getBytes(), Base64.decodeBase64(key));

            result = Base64.encodeBase64String(data_en);

        } catch (Exception e) {

            e.printStackTrace();

        }

        return result;

    }

 

    public static String ideaDecrypt(String data, String key) {

        String result = null;

        try {

            byte[] data_de =decrypt(Base64.decodeBase64(data), Base64.decodeBase64(key));;

            result = new String(data_de);

        } catch (Exception e) {

            e.printStackTrace();

        }

        return result;

    }

 

    public  void work(String str,String password,String data) {

        String key = getKey();

        System.out.println("要加密的原文："+data);

        System.out.println("密钥：" + key);

        String data_en = ideaEncrypt(data, key);

        System.out.println("密文："+data_en);

        String data_de = ideaDecrypt(data_en, key);

        System.out.println("原文："+data_de);

    }

 

}

mport java.util.Scanner;

 

public class Main {

 

    public static void main(String[] args) {

 

        DES des=new DES();

        IDEA idea=new IDEA();

        try {

            int n = 0;

 

            Scanner in = new Scanner(System.in);

            while (n != 3) {

                System.out.println("请选择要使用的加密算法 1.DES加密算法 2.IDEA加密算法");

                System.out.println("3.退出");

                System.out.println("请选择：");

                if (in.hasNextInt()) {

                    n = in.nextInt();

                } else {

                    System.out.println("输入的不是整数，请重新输入：");

                    continue;

                }

                switch (n) {

                    case 1: {

                        String a;

                        Scanner in1 = new Scanner(System.in);

                        System.out.println("选择加密文件：");

                        a = in1.nextLine();

                        des.work("1787878787878787","0E329232EA6D0D73",a);

                        break;

                    }

                    case 2: {

                        String b;

                        Scanner in2 = new Scanner(System.in);

                        System.out.println("选择加密文件：");

                        b = in2.nextLine();

                        idea.work("8787878787878787","0E329232EA6D0D73",b);

                        break;

                    }

                }

            }

        }

 

 

        catch(Exception e)

        {

            System.out.println(e.getMessage());

        }

    }

 

}

public interface Method {

    public abstract void work(String str,String password,String codeStringBegin);

}

3.注意编程规范。