使用RSA创建公钥/私钥对服务器套接字 -Java实例教程集册

Creates a Public/Private Key pair using RSA
transmits the RSA asymmetric public key to the Server
receives data (AES symmetric key) which is encrypted with the RSA asymmetric public key
decrypts the data using the RSA asymmetric private key
has access to AES symmetric key, which was generated on the server




import org.apache.logging.log4j.LogManager;/*时代Java公众号 提 供*/

import org.apache.logging.log4j.Logger;


import javax.crypto.*;

import javax.crypto.spec.IvParameterSpec;

import javax.crypto.spec.SecretKeySpec;

import java.io.*;

import java.net.InetSocketAddress;

import java.net.Socket;

import java.security.*;


public class SecureClient {


    private static final Logger logger = LogManager.getLogger(SecureClient.class);


    public static void main(String [] args) throws NoSuchProviderException, NoSuchAlgorithmException, InvalidAlgorithmParameterException {

        if (args.length != 2) {

            System.err.println(//来自 N  o w  J a v a . c o m

                    "Usage: java SecureClient <host name> <port number>");

            System.exit(1);

        }


        String hostName = args[0];

        int portNumber = Integer.parseInt(args[1]);

        String message = "Just Read the Instructions";


        // generate Public and Private Key

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

        SecureRandom random = SecureRandom.getInstanceStrong();


        keyPairGenerator.initialize(2048, random);

        KeyPair keyPair = keyPairGenerator.generateKeyPair();

        PublicKey publicKey = keyPair.getPublic();

        PrivateKey privateKey = keyPair.getPrivate();


        logger.trace("Public Key: " + publicKey.toString());


        try{

            // Sockets

//            Socket socket = new Socket(hostName, portNumber);

            Socket socket = new Socket();

            socket.connect(new InetSocketAddress(hostName, portNumber), 5000);

            ObjectOutputStream objectOutputStream = new ObjectOutputStream(

                    socket.getOutputStream());

            objectOutputStream.writeObject(publicKey);

            objectOutputStream.flush();


            logger.trace("sent public key");


            InputStream in = socket.getInputStream();

            DataInputStream dis = new DataInputStream(in);


            int len = dis.readInt();

            byte[] encryptedData = new byte[len];

            if (len > 0) {

                dis.readFully(encryptedData);

            }


            logger.trace("received encrypted data");


            // DECRYPTION of AES Key

            Cipher cipher = Cipher.getInstance("RSA/ECB/PKCS1Padding");

            cipher.init(Cipher.DECRYPT_MODE, privateKey);

            SecretKey aesKey = new SecretKeySpec(cipher.doFinal(encryptedData), "AES");


            logger.trace("decrypted the following AES symmetric key: " + aesKey.toString());


            // use the AES key for encrypting a message

            cipher = Cipher.getInstance("AES/CBC/PKCS5Padding");

            byte[] iv = new byte[16];

            random = new SecureRandom();

            random.nextBytes(iv);

            IvParameterSpec ivParameterSpec = new IvParameterSpec(iv);

            cipher.init(Cipher.ENCRYPT_MODE, aesKey, ivParameterSpec);

            encryptedData = cipher.doFinal(message.getBytes("UTF-8"));

            String encrypted =

使用RSA创建公钥/私钥对

在这篇文章中：

目录