20145325张梓靖 实验五 "JAVA的网络编程"

实验内容

使用 JVAV语言 进行网络编程

对明文进行加密

设计过程

• 我完成的是客户端，服务端同伴 20145308刘昊阳 地址为：http://www.cnblogs.com/yg961022/p/5471201.html

• 先生成 DES 秘钥

 KeyPairGenerator kpg=KeyPairGenerator.getInstance("RSA");

        kpg.initialize(1024);

        KeyPair kp=kpg.genKeyPair();

        PublicKey pbkey=kp.getPublic();

        PrivateKey prkey=kp.getPrivate();

        FileOutputStream  f1=new FileOutputStream("Skey_RSA_pub.dat");

        ObjectOutputStream b1=new  ObjectOutputStream(f1);

        b1.writeObject(pbkey);

        FileOutputStream  f2=new FileOutputStream("Skey_RSA_priv.dat");

        ObjectOutputStream b2=new  ObjectOutputStream(f2);

        b2.writeObject(prkey);

FileInputStream f=new FileInputStream("key1.dat");

	ObjectInputStream b=new ObjectInputStream(f);

	Key k=(Key)b.readObject( );

        byte[ ] kb=k.getEncoded( );

        FileOutputStream  f2=new FileOutputStream("keykb1.dat");

	   f2.write(kb);

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

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

        }

• 将输入的明文"Hello World! 20145325"进行加密

	    String s="Hello World! 20145325";

		FileInputStream f=new FileInputStream("key1.dat");

		ObjectInputStream b=new ObjectInputStream(f);

		Key k=(Key)b.readObject( );

		Cipher cp=Cipher.getInstance("DESede");

        cp.init(Cipher.ENCRYPT_MODE, k);

        byte ptext[]=s.getBytes("UTF8");

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

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

        }

        System.out.println("");

        byte ctext[]=cp.doFinal(ptext);

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

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

        }

		FileOutputStream f2=new FileOutputStream("SEnc.dat");

        f2.write(ctext);

• 将 DES 的秘钥用服务端的公钥进行 RSA 加密：

FileInputStream f = new FileInputStream("Skey_RSA_pub.dat");

        ObjectInputStream b = new ObjectInputStream(f);

        RSAPublicKey pbk = (RSAPublicKey) b.readObject();

        BigInteger e = pbk.getPublicExponent();

        BigInteger n = pbk.getModulus();

        System.out.println("e= " + e);

        System.out.println("n= " + n);

        byte ptext[] = s.getBytes("UTF8");

        BigInteger m = new BigInteger(ptext);

        BigInteger c = m.modPow(e, n);

        System.out.println("c= " + c);

        String cs = c.toString();

        BufferedWriter out =

                new BufferedWriter(new OutputStreamWriter(

                        new FileOutputStream("Enc_RSA.dat")));

        out.write(cs, 0, cs.length());

        out.close();

• 将密文和加密的秘钥通过网络编程传输过去：

Socket socket = null;

        InputStream is = null;

        OutputStream os = null;

        //服务器端IP地址

        String serverIP = "192.168.199.107";

        //服务器端端口号

        int port = 10000;

        //发送内容

        String data[] ={"**"，"**"};

        try {

            //建立连接

            socket = new Socket(serverIP,port);

            //初始化流

            os = socket.getOutputStream();

            is = socket.getInputStream();

            byte[] b = new byte[1024];

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

                //发送数据

                os.write(data[i].getBytes());

                //接收数据

                int n = is.read(b);

                //输出反馈数据

                System.out.println("服务器反馈：" + new String(b,0,n));

            }

        } catch (Exception e) {

            e.printStackTrace(); //打印异常信息

        }finally{

            try {

                //关闭流和连接

                is.close();

                os.close();

                socket.close();

            } catch (Exception e2) {}

        }

• 服务端打开监听，客户端进行传输，服务端收到数据，然后再进行解密