Java SSL Socket通讯示例

上一篇《OpenSSL与KeyStore指令小集》里面说到，最近研究SSL加密，会给出一个Java的小示例。复制一份可以运行的代码到生产上是非常不负责任的行为，不过小示例可以带我们入门，快速看清事物的本质。罗马不是一天建成的。

本文将给出一个Java SSL Socket的小例子，包括了Server和Client。希望大家上手之后，要多去研究相关的资料，理解基础概念。Java的优点是封装得比较彻底，需要介入的地方比较少，缺点是随着Java版本的升级和发展，会有很多新的概念和类涌出来，都要搞清楚要费不少力，另外代码量也比较大(生产级别的代码)。

具体代码

从最简单来说，Java里面只需要配置几个系统属性，创建及调用几个SSL相关的对象即可。这四个属性分别是:

javax.net.ssl.keyStore
本方的密码，证书等存放地点(KeyStore文件地址)。
javax.net.ssl.keyStorePassword
KeyStore的密码。没有密码可以不填。
javax.net.ssl.trustStore
受信任证书的存放地点(TrustKeyStore文件地址)。
javax.net.ssl.trustStorePassword
TrustKeyStore的密码。没有密码可以不填。

KeyStore类型默认是JKS类型的，不是的话，还需要设置 javax.net.ssl.keyStoreType和javax.net.ssl.trustStoreType。

Server端代码

每一次收新的连接，都新开一个线程接待。生产上请用线程池等技术。更推荐用Netty或Mina等框架处理。

[java] view plain copy print?

public class SslServer {
public static void main(String[] args) throws Exception {
System.setProperty("javax.net.debug", "ssl,handshake");
System.setProperty("javax.net.ssl.keyStore", "./cfg/server.jks");
System.setProperty("javax.net.ssl.keyStorePassword", "123456");
System.setProperty("javax.net.ssl.trustStore", "./cfg/clienttrust.jks");
System.setProperty("javax.net.ssl.trustStorePassword", "123456");
SSLServerSocketFactory serverSocketFactory = (SSLServerSocketFactory) SSLServerSocketFactory
.getDefault();
SSLServerSocket serverSocket = (SSLServerSocket) serverSocketFactory
.createServerSocket(9100);
// 要求客户端身份验证
serverSocket.setNeedClientAuth(true);
while (true) {
SSLSocket socket = (SSLSocket) serverSocket.accept();
Accepter accepter = new Accepter(socket);
accepter.service();
}
}
static class Accepter implements Runnable {
private SSLSocket socket;
public Accepter(SSLSocket socket) {
this.socket = socket;
}
public void service() {
Thread thread = new Thread(this);
thread.start();
}
@Override
public void run() {
try {
InputStream inputStream = socket.getInputStream();
InputStreamReader inputstreamreader = new InputStreamReader(
inputStream);
BufferedReader bufferedreader = new BufferedReader(
inputstreamreader);
String string = null;
while ((string = bufferedreader.readLine()) != null) {
System.out.println(string);
System.out.flush();
}
} catch (Exception e) {
// replace with other code
e.printStackTrace();
}
}
}
}

public class SslServer {
  public static void main(String[] args) throws Exception {
   System.setProperty("javax.net.debug", "ssl,handshake");

   System.setProperty("javax.net.ssl.keyStore", "./cfg/server.jks");
   System.setProperty("javax.net.ssl.keyStorePassword", "123456");
   System.setProperty("javax.net.ssl.trustStore", "./cfg/clienttrust.jks");
   System.setProperty("javax.net.ssl.trustStorePassword", "123456");

   SSLServerSocketFactory serverSocketFactory = (SSLServerSocketFactory) SSLServerSocketFactory
     .getDefault();
   SSLServerSocket serverSocket = (SSLServerSocket) serverSocketFactory
     .createServerSocket(9100);
   // 要求客户端身份验证
   serverSocket.setNeedClientAuth(true);

   while (true) {
    SSLSocket socket = (SSLSocket) serverSocket.accept();
    Accepter accepter = new Accepter(socket);
    accepter.service();
   }
  }

  static class Accepter implements Runnable {
   private SSLSocket socket;

   public Accepter(SSLSocket socket) {
    this.socket = socket;
   }

   public void service() {
    Thread thread = new Thread(this);
    thread.start();
   }

   @Override
   public void run() {
    try {
     InputStream inputStream = socket.getInputStream();

     InputStreamReader inputstreamreader = new InputStreamReader(
       inputStream);
     BufferedReader bufferedreader = new BufferedReader(
       inputstreamreader);

     String string = null;
     while ((string = bufferedreader.readLine()) != null) {
      System.out.println(string);
      System.out.flush();
     }
    } catch (Exception e) {
     // replace with other code
     e.printStackTrace();
    }
   }
  }
 }

Client代码

建立连接，并发一个消息给Server。很简单。记得换行符以及调用flush方法。

[java] view plain copy print?

public class SslClient {
public static void main(String[] args) throws Exception {
System.setProperty("javax.net.debug", "ssl,handshake");
System.setProperty("javax.net.ssl.keyStore", "./cfg/client.jks");
System.setProperty("javax.net.ssl.keyStorePassword", "123456");
System.setProperty("javax.net.ssl.trustStore", "./cfg/servertrust.jks");
System.setProperty("javax.net.ssl.trustStorePassword", "123456");
SSLSocketFactory sslsocketfactory = (SSLSocketFactory) SSLSocketFactory
.getDefault();
SSLSocket sslsocket = (SSLSocket) sslsocketfactory.createSocket(
"127.0.0.1", 9100);
OutputStream outputStream = sslsocket.getOutputStream();
BufferedWriter bufferedWriter = new BufferedWriter(
new OutputStreamWriter(outputStream));
bufferedWriter.write("沉睡的雄狮\n");
bufferedWriter.flush();
TimeUnit.SECONDS.sleep(2000);
}
}

public class SslClient {
  public static void main(String[] args) throws Exception {
   System.setProperty("javax.net.debug", "ssl,handshake");

   System.setProperty("javax.net.ssl.keyStore", "./cfg/client.jks");
   System.setProperty("javax.net.ssl.keyStorePassword", "123456");
   System.setProperty("javax.net.ssl.trustStore", "./cfg/servertrust.jks");
   System.setProperty("javax.net.ssl.trustStorePassword", "123456");

   SSLSocketFactory sslsocketfactory = (SSLSocketFactory) SSLSocketFactory
     .getDefault();
   SSLSocket sslsocket = (SSLSocket) sslsocketfactory.createSocket(
     "127.0.0.1", 9100);

   OutputStream outputStream = sslsocket.getOutputStream();
   BufferedWriter bufferedWriter = new BufferedWriter(
     new OutputStreamWriter(outputStream));
   bufferedWriter.write("沉睡的雄狮\n");
   bufferedWriter.flush();

   TimeUnit.SECONDS.sleep(2000);
  }
 }

结束语

JDK后来加了SSLEngine这个类，具有异步通讯的能力。不过看官方文档，给出的代码很长。还是那句话，有条件的推荐用Netty或者Mina来处理通讯的问题，应该会比自己写的性能好一些。

Java官方SSL Socket文档

原文地址：http://blog.csdn.net/kimylrong/article/details/43603815

Java SSL Socket通讯示例

具体代码

Server端代码

Client代码

结束语

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