526互联

每日随笔——工厂方法模式

发布时间 2023-11-09 09:43:42作者: 伽澄

[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；

3.注意编程规范。

 源代码：

Test1

package test;
import java.util.Scanner;

public class test1{

    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: {

                        des.work("1787878787878787", "0E329232EA6D0D73");
                        break;
                    }
                    case 2: {
                        idea.work("8787878787878787", "0E329232EA6D0D73");
                        break;
                    }
                }
            }
        } catch (Exception e) {
            System.out.println(e.getMessage());
        }
    }
}

Method


package test;

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


MethodFactory


package test;

public interface MethodFactory {
    public Method produceMethod();
}

DES


package test;

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 = "信2105-3 20213892 刘家诚"; // 要加密的明文
        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();
        }
    }

    public static void main(String[] args) {
        // TODO Auto-generated method stub
        System.out.println("DES加密算法");
        DES des = new DES();
        try {
            des.work("8787878787878787", "0E329232EA6D0D73");

        } catch (Exception e) {
            System.out.println(e.getMessage());
        }
    }

}

DES Factory


package test;

public class DESFactory implements MethodFactory {
    public DES produceMethod() {
        System.out.println("使用DES算法");
        return new DES();
    }
}

IDEA


package test;

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;
import java.util.Scanner;

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 = "20213892刘家诚";
        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);
    }

    public static void main(String[] args) {
        // TODO Auto-generated method stub
        System.out.println("IDEA加密算法");
        IDEA idea = new IDEA();
        try {
            idea.work("8787878787878787", "0E329232EA6D0D73");
        } catch (Exception e) {
            System.out.println(e.getMessage());
        }
    }

}

IDEAFastory

package test;

public class IDEAFactory implements MethodFactory {
    public IDEA produceMethod() {
        System.out.println("使用IDEA算法");
        return new IDEA();
    }
}