工厂方法实现DES和IDEA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，我现在使用工厂方法模式来实现加密算法系统。

main.java

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("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());
             }
        }
    }

主界面用于调用Method接口下的DES.java和IDEA.java

Method.java

public interface Method {
    public abstract void work(String str,String password,String codeStringBegin);
}

DES.java

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();
        }
    }


}

IDEA.java

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);
        }

}