工厂方法模式实现DES和IDEA加密算法

1、类图

 

2、代码：

（1）MethodFactory.java

package bean;

 

public interface MethodFactory {

    public Method produceMethod();

}

（2）Method.java

package bean;

 

public interface Method {

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

}

（3）DESFactory.java

package bean;

 

public class DESFactory implements MethodFactory {

    public DES produceMethod() {

        System.out.println("使用DES算法");

        return new DES();

    }

}

（4）IDEAFactory.java

package bean;

 

public class IDEAFactory implements MethodFactory {

    public IDEA produceMethod() {

        System.out.println("使用IDEA算法");

        return new IDEA();

    }

}

（5）DES.java

package bean;

 

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:"+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();

        }

    }

 

}

（6）IDEA.java

package bean;

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.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);

        }

 

}

（7）main.java

package bean;

import 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("************************************");

                System.out.println("请选择要使用的加密算法：");

                System.out.println("1.DES加密算法");

                System.out.println("2.IDEA加密算法");

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

                System.out.println("************************************");

                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());

             }

        }

    }

 

3、结果截图：