SSLServerSocket problem

Question

I am trying to write a stand alone SSLSocket application. I created the certificate with this line:
keytool -genkey -keystore serverkeys -keyalg rsa -alias chat
The SSLServerSocket gets created with no issues. The server accepts connections from the client without complaint. The problem is when I try and create the IO streams. On the server side this is the exception:
javax.net.ssl.SSLHandshakeException: Received fatal alert: certificate_unknown
     at com.sun.net.ssl.internal.ssl.Alerts.getSSLException(Alerts.java:150)
     at com.sun.net.ssl.internal.ssl.Alerts.getSSLException(Alerts.java:117)
     at com.sun.net.ssl.internal.ssl.SSLSocketImpl.recvAlert(SSLSocketImpl.java:1584)
     at com.sun.net.ssl.internal.ssl.SSLSocketImpl.readRecord(SSLSocketImpl.java:866)
     at com.sun.net.ssl.internal.ssl.SSLSocketImpl.performInitialHandshake(SSLSocketImpl.java:1030)
     at com.sun.net.ssl.internal.ssl.SSLSocketImpl.readDataRecord(SSLSocketImpl.java:678)
     at com.sun.net.ssl.internal.ssl.AppInputStream.read(AppInputStream.java:75)
     at java.io.ObjectInputStream$PeekInputStream.read(ObjectInputStream.java:2213)
     at java.io.ObjectInputStream$PeekInputStream.readFully(ObjectInputStream.java:2226)
     at java.io.ObjectInputStream$BlockDataInputStream.readShort(ObjectInputStream.java:2694)
     at java.io.ObjectInputStream.readStreamHeader(ObjectInputStream.java:761)
     at java.io.ObjectInputStream.<init>(ObjectInputStream.java:277)
     at secureChatServer.network.SecureServer.createIOStreams(SecureServer.java:131)
     at secureChatServer.network.ControllerServer.run(ControllerServer.java:50)
     at java.lang.Thread.run(Thread.java:595)here is the relevant code:
public SecureServer(String IPAddress, int port, int backlog)throws SecureChatException
          try
               //set up public private key
               kStore = KeyStore.getInstance("JKS");
               kStore.load(new FileInputStream(KEY), KP);
               keyFactory = KeyManagerFactory.getInstance("SunX509");
               keyFactory.init(kStore, KP);
               sc = SSLContext.getInstance(PROTOCOL);
               sc.init(keyFactory.getKeyManagers(), null,null);
               //set up server factory and socket
               servFactory= sc.getServerSocketFactory();
               servSock = (SSLServerSocket)servFactory.createServerSocket(port, backlog, InetAddress.getByName(IPAddress));
               and
public void run()
          short val;
          int timeout=2000;
          while(!stop)
               try
                    sock = (SSLSocket)servSock.accept();
                    createIOStreams();
public void createIOStreams() throws IOException
          read = new ObjectInputStream(sock.getInputStream());
          write = new ObjectOutputStream(sock.getOutputStream());
On the client side, I get this exception:
secureChat.exception.SecureChatException: sun.security.validator.ValidatorException: PKIX path building failed: sun.security.provider.certpath.SunCertPathBuilderException: unable to find valid certification path to requested target
     at secureChat.network.SecureConnection.connect(SecureConnection.java:69)
     at secureChat.network.RoutineBase.connect(RoutineBase.java:42)
     at secureChat.network.SignUp.<init>(SignUp.java:34)
     at secureChat.listeners.SignUpFormListener.actionPerformed(SignUpFormListener.java:39)
     at javax.swing.AbstractButton.fireActionPerformed(AbstractButton.java:1849)
     at javax.swing.AbstractButton$Handler.actionPerformed(AbstractButton.java:2169)
     at javax.swing.DefaultButtonModel.fireActionPerformed(DefaultButtonModel.java:420)
     at javax.swing.DefaultButtonModel.setPressed(DefaultButtonModel.java:258)
     at javax.swing.plaf.basic.BasicButtonListener.mouseReleased(BasicButtonListener.java:236)
     at java.awt.Component.processMouseEvent(Component.java:5488)
     at javax.swing.JComponent.processMouseEvent(JComponent.java:3126)
     at java.awt.Component.processEvent(Component.java:5253)
     at java.awt.Container.processEvent(Container.java:1966)
     at java.awt.Component.dispatchEventImpl(Component.java:3955)
     at java.awt.Container.dispatchEventImpl(Container.java:2024)
     at java.awt.Component.dispatchEvent(Component.java:3803)
     at java.awt.LightweightDispatcher.retargetMouseEvent(Container.java:4212)
     at java.awt.LightweightDispatcher.processMouseEvent(Container.java:3892)
     at java.awt.LightweightDispatcher.dispatchEvent(Container.java:3822)
     at java.awt.Container.dispatchEventImpl(Container.java:2010)
     at java.awt.Window.dispatchEventImpl(Window.java:1778)
     at java.awt.Component.dispatchEvent(Component.java:3803)
     at java.awt.EventQueue.dispatchEvent(EventQueue.java:463)
     at java.awt.EventDispatchThread.pumpOneEventForHierarchy(EventDispatchThread.java:242)
     at java.awt.EventDispatchThread.pumpEventsForHierarchy(EventDispatchThread.java:163)
     at java.awt.EventDispatchThread.pumpEvents(EventDispatchThread.java:157)
     at java.awt.EventDispatchThread.pumpEvents(EventDispatchThread.java:149)
     at java.awt.EventDispatchThread.run(EventDispatchThread.java:110)
The code:
sock = (SSLSocket)sockFactory.createSocket(Properties.getIPAddress(),Properties.getPort());
               write=new ObjectOutputStream(sock.getOutputStream());
               read=new ObjectInputStream(sock.getInputStream());What am I missing?

Answer 1

The SSL handshake only happens when you do the first I/O, not at the accept stage.
Your client doesn't trust the server's certificate. You need to export the server's certificate and import it into the client's truststore.
Or have the server's certificate signed by a CA that the client already trusts.