I'm writing a Client Server application with RMI and I want to secure the traffic between Client and Server. I want to use the SslRMIClientSocketFactory and SslRMIServerSocketFactory for this.
I've created a keypair for the Client and for the Server (client.private and server.private) and also a certificate for the Client and for the Server (client.public and server.public).
I think I'm correctly adding the keypair to the keystore and the certificate to the truststore. I only use the custom Socket Factory's when exporting my objects, not when I'm creating the RMI Registry. Here's my code:
Server:
public class Server implements ServerProtocol {
public Server() {
super();
SecureRandom sr = new SecureRandom();
sr.nextInt();
KeyStore clientKeyStore = KeyStore.getInstance("JKS");
FileInputStream client = new FileInputStream("src/client.public");
String passphrase = //
clientKeyStore.load(client, passphrase.toCharArray());
client.close();
KeyStore serverKeyStore = KeyStore.getInstance("JKS");
FileInputStream server = new FileInputStream("src/server.private");
String password = //
serverKeyStore.load(server, password.toCharArray());
server.close();
TrustManagerFactory tmf = TrustManagerFactory.getInstance("SunX509");
tmf.init(clientKeyStore);
KeyManagerFactory kmf = KeyManagerFactory.getInstance("SunX509");
kmf.init(serverKeyStore, password.toCharArray());
SSLContext SSLC = SSLContext.getInstance("TLS");
SSLC.init(kmf.getKeyManagers(), tmf.getTrustManagers(), sr);
SslRMIClientSocketFactory csf = new SslRMIClientSocketFactory();
SslRMIServerSocketFactory ssf = new SslRMIServerSocketFactory(null, null, true);
LocateRegistry.createRegistry(2020).rebind("server", this);
UnicastRemoteObject.exportObject(this, 2020, csf, ssf);
}
public void sayHello() {
System.out.println("Hello");
}
}
Client:
public class Client implements ClientProtocol {
public Client() {
SecureRandom sr = new SecureRandom();
sr.nextInt();
KeyStore serverKeyStore = KeyStore.getInstance("JKS");
FileInputStream server = new FileInputStream("src/server.public");
String passphrase = //
serverKeyStore.load(server, passphrase.toCharArray());
server.close();
KeyStore clientKeyStore = KeyStore.getInstance("JKS");
FileInputStream client = new FileInputStream("src/client.private");
String password = //
clientKeyStore.load(client, password.toCharArray());
client.close();
TrustManagerFactory tmf = TrustManagerFactory.getInstance("SunX509");
tmf.init(serverKeyStore);
KeyManagerFactory kmf = KeyManagerFactory.getInstance("SunX509");
kmf.init(clientKeyStore, password.toCharArray());
SSLContext SSLC = SSLContext.getInstance("TLS");
SSLC.init(kmf.getKeyManagers(), tmf.getTrustManagers(), sr);
SslRMIClientSocketFactory csf = new SslRMIClientSocketFactory();
SslRMIServerSocketFactory ssf = new SslRMIServerSocketFactory(null, null, true);
Registry reg = LocateRegistry.getRegistry("localhost", 2020);
serverStub = (ServerService) reg.lookup("server");
stub = (ClientService) UnicastRemoteObject.exportObject(this, 2020, csf, ssf);
serverStub.sayHello();
}
}
When I run this, I get the following error message:
javax.net.ssl.SSLHandshakeException: Received fatal alert: handshake_failure
at com.sun.net.ssl.internal.ssl.Alerts.getSSLException(Alerts.java:174)
at com.sun.net.ssl.internal.ssl.Alerts.getSSLException(Alerts.java:136)
at com.sun.net.ssl.internal.ssl.SSLSocketImpl.recvAlert(SSLSocketImpl.java:1822)
at com.sun.net.ssl.internal.ssl.SSLSocketImpl.readRecord(SSLSocketImpl.java:1004)
at com.sun.net.ssl.internal.ssl.SSLSocketImpl.performInitialHandshake(SSLSocketImpl.java:1188)
at com.sun.net.ssl.internal.ssl.SSLSocketImpl.writeRecord(SSLSocketImpl.java:654)
at com.sun.net.ssl.internal.ssl.AppOutputStream.write(AppOutputStream.java:100)
at java.io.BufferedOutputStream.flushBuffer(BufferedOutputStream.java:65)
at java.io.BufferedOutputStream.flush(BufferedOutputStream.java:123)
at java.io.DataOutputStream.flush(DataOutputStream.java:106)
at sun.rmi.transport.tcp.TCPChannel.createConnection(TCPChannel.java:211)
at sun.rmi.transport.tcp.TCPChannel.newConnection(TCPChannel.java:184)
at sun.rmi.server.UnicastRef.invoke(UnicastRef.java:110)
at java.rmi.server.RemoteObjectInvocationHandler.invokeRemoteMethod(RemoteObjectInvocationHandler.java:178)
at java.rmi.server.RemoteObjectInvocationHandler.invoke(RemoteObjectInvocationHandler.java:132)
at com.sun.proxy.$Proxy0.sayHello(Unknown Source)
at project.Client.<init>(Client.java:100)
at project.Client.main(Client.java:785)
I used the following commands to create the keys, export and import them:
keytool -genkey -alias clientprivate -keystore client.private -storetype JKS -keyalg rsa -storepass * -keypass * -validity 360
keytool -genkey -alias serverprivate -keystore server.private -storetype JKS -keyalg rsa -storepass * -keypass * -validity 360
keytool -export -alias clientprivate -keystore client.private -file temp.key -storepass *
keytool -import -noprompt -alias clientpublic -keystore client.public -file temp.key -storepass *
keytool -export -alias serverprivate -keystore server.private -file temp.key -storepass *
keytool -import -noprompt -alias serverpublic -keystore server.public -file temp.key -storepass *
Do I need to configure something else to make this work? Something in Eclipse?
You're creating the Registry with SSL socket factories but you're not supplying a socket factory to getRegistry().
I was able to solve this by avoiding the build-in Java classes SslRMIClientSocketFactory and SslRMIServerSocketFactory and creating my own classes which implement the RMIClientSocketFactory and RMIServerSocketFactory interfaces.
RMIClientSocketFactory
public class MyClientSocketFactory implements RMIClientSocketFactory, Serializable {
public MyClientSocketFactory() {}
public Socket createSocket(String host, int port) {
SecureRandom sr = new SecureRandom();
sr.nextInt();
KeyStore serverKeyStore = KeyStore.getInstance("JKS");
FileInputStream server = new FileInputStream("src/server.public");
String passphrase = //
serverKeyStore.load(server, passphrase.toCharArray());
server.close();
KeyStore clientKeyStore = KeyStore.getInstance("JKS");
FileInputStream client = new FileInputStream("src/client.private");
String password = //
clientKeyStore.load(client, password.toCharArray());
client.close();
TrustManagerFactory tmf = TrustManagerFactory.getInstance("SunX509");
tmf.init(serverKeyStore);
KeyManagerFactory kmf = KeyManagerFactory.getInstance("SunX509");
kmf.init(clientKeyStore, password.toCharArray());
SSLContext SSLC = SSLContext.getInstance("TLS");
SSLC.init(kmf.getKeyManagers(), tmf.getTrustManagers(), sr);
SSLSocketFactory sf = SSLC.getSocketFactory();
SSLSocket socket = (SSLSocket) sf.createSocket(host, port);
return socket;
}
public int hashCode() {
return getClass().hashCode();
}
public boolean equals(Object obj) {
if (obj == this) {
return true;
} else if (obj == null || getClass() != obj.getClass()) {
return false;
}
return true;
}
}
RMIServerSocketFactory
public class MyServerSocketFactory implements RMIClientSocketFactory, Serializable {
public MyServerSocketFactory() {}
public Socket createSocket(String host, int port) {
SecureRandom sr = new SecureRandom();
sr.nextInt();
KeyStore clientKeyStore = KeyStore.getInstance("JKS");
FileInputStream client = new FileInputStream("src/client.public");
String passphrase = //
clientKeyStore.load(client, passphrase.toCharArray());
client.close();
KeyStore serverKeyStore = KeyStore.getInstance("JKS");
FileInputStream server = new FileInputStream("src/server.private");
String password = //
serverKeyStore.load(server, password.toCharArray());
server.close();
TrustManagerFactory tmf = TrustManagerFactory.getInstance("SunX509");
tmf.init(serverKeyStore);
KeyManagerFactory kmf = KeyManagerFactory.getInstance("SunX509");
kmf.init(clientKeyStore, password.toCharArray());
SSLContext SSLC = SSLContext.getInstance("TLS");
SSLC.init(kmf.getKeyManagers(), tmf.getTrustManagers(), sr);
SSLServerSocketFactory sf = SSLC.getServerSocketFactory();
SSLServerSocket socket = (SSLServerSocket) sf.createServerSocket(host, port);
return socket;
}
public int hashCode() {
return getClass().hashCode();
}
public boolean equals(Object obj) {
if (obj == this) {
return true;
} else if (obj == null || getClass() != obj.getClass()) {
return false;
}
return true;
}
}
Related
I want to load KeyStore certificate from X509Certificate[] object but for now, I just load the certificate from Assets. I don't want to load the certificate from the file but from X509Certificate object. Any solutions?
GetCertificateChain:
private X509Certificate[] GetCertificateChain(string alias)
{
try
{
return KeyChain.GetCertificateChain(this, alias);
}
catch (KeyChainException e)
{
}
return null;
}
Load certificate:
Stream iss = Application.Context.Assets.Open("badssl.com-cuient.p12");
hchandler.SetClientCertificate(iss, "badssl.com".ToCharArray());
private IKeyManager[] GetKeyManagersFromClientCert(Stream pkcs12, char[] password)
{
if (pkcs12 != null)
{
KeyStore keyStore = KeyStore.GetInstance("pkcs12");
keyStore.Load(pkcs12, password);
KeyManagerFactory kmf = KeyManagerFactory.GetInstance("x509");
kmf.Init(keyStore, password);
return kmf.GetKeyManagers();
}
return null;
}
I've already saw this question: Need to do a GET&POST HTTPS Request using a .cer certificate
Mine is quite different:
It is possible to make an HTTPS request using Java (vanilla, or using any library), trusting a server certificate and providing a client certificate, without using a keystore but using plain certificates?
I have both certs in X.509 format, and I don't want to have every certificate in a keystore.
This is a rough example. Represents the X509KeyManager decorator.
KeyManagerFactory kmf = KeyManagerFactory.getInstance(KeyManagerFactory.getDefaultAlgorithm());
kmf.init(null, null);
X509KeyManager manager = (X509KeyManager) kmf.getKeyManagers()[0];
KeyManager km = new X509KeyManager() {
#Override
public String[] getClientAliases(String s, Principal[] principals) {
return manager.getServerAliases(s, principals);
}
#Override
public String chooseClientAlias(String[] strings, Principal[] principals, Socket socket) {
return manager.chooseClientAlias(strings, principals, socket);
}
#Override
public String[] getServerAliases(String s, Principal[] principals) {
return manager.getServerAliases(s, principals);
}
#Override
public String chooseServerAlias(String s, Principal[] principals, Socket socket) {
return manager.chooseServerAlias(s, principals, socket);
}
#Override
public X509Certificate[] getCertificateChain(String s) {
// You can use `s` to select the appropriate file
try {
File file = new File("path to certificate");
try(InputStream is = new FileInputStream(file)) {
CertificateFactory factory = CertificateFactory.getInstance("X.509");
return new X509Certificate[] {
(X509Certificate) factory.generateCertificate(is)
};
}
}
catch (CertificateException| IOException e) {
e.printStackTrace();
}
return null;
}
#Override
public PrivateKey getPrivateKey(String s) {
// You can use `s` to select the appropriate file
// load and private key from selected certificate
// this use for certificate authorisation
try {
File file = new File("private key file");
byte buffer[] = Files.readAllBytes(file.toPath());
KeySpec keySpec = new PKCS8EncodedKeySpec(buffer);
KeyFactory factory = KeyFactory.getInstance("RSA");
return factory.generatePrivate(keySpec);
}
catch (NoSuchAlgorithmException | IOException | InvalidKeySpecException e) {
e.printStackTrace();
}
return null;
}
};
TrustManager tm = new X509TrustManager() {
#Override
public void checkClientTrusted(X509Certificate[] x509Certificates, String s) throws CertificateException {
}
#Override
public void checkServerTrusted(X509Certificate[] x509Certificates, String s) throws CertificateException {
}
#Override
public X509Certificate[] getAcceptedIssuers() {
try {
File file = new File("path to certificate");
try(InputStream is = new FileInputStream(file)) {
CertificateFactory factory = CertificateFactory.getInstance("X.509");
return new X509Certificate[] {
(X509Certificate) factory.generateCertificate(is)
};
}
}
catch (CertificateException| IOException e) {
e.printStackTrace();
}
return null;
}
};
TrustManagerFactory tmf = TrustManagerFactory.getInstance(TrustManagerFactory.getDefaultAlgorithm());
tmf.init((KeyStore)null); //use java system trust certificates
TrustManager managers[] = new TrustManager[tmf.getTrustManagers().length + 1];
System.arraycopy(tmf.getTrustManagers(), 0, managers, 0, tmf.getTrustManagers().length);
managers[managers.length - 1] = tm;
SSLContext context = SSLContext.getInstance("TLS");
context.init(new KeyManager[]{ km }, managers, new SecureRandom());
URL url = new URL("https://............/");
HttpsURLConnection connection = (HttpsURLConnection) url.openConnection();
connection.setSSLSocketFactory(connection.getSSLSocketFactory());
connection.connect();
If you really don't want to create a new keystore file, then can use KeyStore API to create in memory and load certificate directly.
InputStream is = new FileInputStream("somecert.cer");
// You could get a resource as a stream instead.
CertificateFactory cf = CertificateFactory.getInstance("X.509");
X509Certificate caCert = (X509Certificate)cf.generateCertificate(is);
TrustManagerFactory tmf = TrustManagerFactory
.getInstance(TrustManagerFactory.getDefaultAlgorithm());
KeyStore ks = KeyStore.getInstance(KeyStore.getDefaultType());
ks.load(null); // You don't need the KeyStore instance to come from a file.
ks.setCertificateEntry("caCert", caCert);
tmf.init(ks);
SSLContext sslContext = SSLContext.getInstance("TLS");
sslContext.init(null, tmf.getTrustManagers(), null);
Alternatively, if you want to avoid modifying your default cacerts file, then you'll need to implement your own TrustManager. However a TrustManager needs a keystore to load, so you can either create a new keystore file importing just your certificate.
keytool -import -alias ca -file somecert.cer -keystore truststore.jks -storepass changeit
And use something like following snippet to load the keystore file.
TrustManagerFactory tmf = TrustManagerFactory
.getInstance(TrustManagerFactory.getDefaultAlgorithm());
// Using null here initialises the TMF with the default trust store.
tmf.init((KeyStore) null);
// Get hold of the default trust manager
X509TrustManager defaultTm = null;
for (TrustManager tm : tmf.getTrustManagers()) {
if (tm instanceof X509TrustManager) {
defaultTm = (X509TrustManager) tm;
break;
}
}
FileInputStream myKeys = new FileInputStream("truststore.jks");
// Do the same with your trust store this time
// Adapt how you load the keystore to your needs
KeyStore myTrustStore = KeyStore.getInstance(KeyStore.getDefaultType());
myTrustStore.load(myKeys, "password".toCharArray());
myKeys.close();
tmf = TrustManagerFactory
.getInstance(TrustManagerFactory.getDefaultAlgorithm());
tmf.init(myTrustStore);
SSLContext sslContext = SSLContext.getInstance("TLS");
sslContext.init(null, tmf.getTrustManagers(), null);
I'm making a custom HTTP/1.1 server implementation in Java. It's working fine in HTTP mode, but I also want to support HTTPS. I haven't generated a certificate for the server yet, but it should at least be trying to connect. I set the protocol and cipher suite to the same settings as google.com (TLS 1.2, ECDHE_RSA, AES_128_GCM), so I know Chrome supports them.
But when I try to connect to https://localhost in Chrome, it gives ERR_SSL_VERSION_OR_CIPHER_MISMATCH (localhost uses an unsupported protocol) error. On the Java side, I get "no cipher suites in common" error.
Java Code:
public class Server {
private final String dir;
private final ServerSocket server;
private final SSLServerSocket sslServer;
public static String jarDir() {
String uri = ClassLoader.getSystemClassLoader().getResource(".").getPath();
try { return new File(URLDecoder.decode(uri,"UTF-8")).getPath()+File.separator; }
catch (Exception e) { return null; }
}
private static SSLContext createSSLContext(String cert, char[] pass) throws Exception {
/*//Load KeyStore in JKS format:
KeyStore keyStore = KeyStore.getInstance("jks");
keyStore.load(new FileInputStream(cert), pass);
//Create key manager:
KeyManagerFactory kmFactory = KeyManagerFactory.getInstance("SunX509");
kmFactory.init(keyStore, pass); KeyManager[] km = kmFactory.getKeyManagers();
//Create trust manager:
TrustManagerFactory tmFactory = TrustManagerFactory.getInstance("SunX509");
tmFactory.init(keyStore); TrustManager[] tm = tmFactory.getTrustManagers();
//Create SSLContext with protocol:
SSLContext ctx = SSLContext.getInstance("TLSv1.2");
ctx.init(km, tm, null); return ctx;*/
SSLContext ctx = SSLContext.getInstance("TLSv1.2");
ctx.init(null, null, null); return ctx;
}
Server(String localPath, int port) throws Exception {
this(localPath, port, 0);
}
//Server is being initialized with:
//new Server("root", 80, 443);
Server(String localPath, int port, int httpsPort) throws Exception {
dir = localPath; File fdir = new File(jarDir(), dir);
if(!fdir.isDirectory()) throw new Exception("No such directory '"+fdir.getAbsolutePath()+"'!");
//Init Server:
server = new ServerSocket(port);
if(httpsPort > 0) {
SSLContext ctx = createSSLContext("cert.jks", "pass".toCharArray());
sslServer = (SSLServerSocket)ctx.getServerSocketFactory().createServerSocket(httpsPort);
//TLS_DH_anon_WITH_AES_128_GCM_SHA256
sslServer.setEnabledCipherSuites(new String[]{"TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256"});
sslServer.setEnabledProtocols(new String[]{"TLSv1.2"});
//Also does not work, same error:
//sslServer.setEnabledCipherSuites(sslServer.getSupportedCipherSuites());
//sslServer.setEnabledProtocols(sslServer.getSupportedProtocols());
} else sslServer = null;
/*new Thread(() -> { while(true) try {
new HTTPSocket(server.accept(), this);
} catch(Exception e) { Main.err("HTTP Server Error",e); }}).start();*/
if(httpsPort > 0) new Thread(() -> { while(true) try {
new HTTPSocket(sslServer.accept(), this);
} catch(Exception e) { Main.err("HTTPS Server Error",e); }}).start();
}
/* ... Other Stuff ... */
}
EDIT: I generated a certificate using keytool -genkey -keyalg RSA -alias selfsigned -keystore cert.jks -storepass password -validity 360 -keysize 2048, but now Java throws Keystore was tampered with, or password was incorrect error.
Like I said in the comments, using "password" in keyStore.load solved the issue.
private static SSLContext createSSLContext(String cert, char[] pass) throws Exception {
//Load KeyStore in JKS format:
KeyStore keyStore = KeyStore.getInstance("jks");
keyStore.load(new FileInputStream(cert), "password".toCharArray());
//Create key manager:
KeyManagerFactory kmFactory = KeyManagerFactory.getInstance("SunX509");
kmFactory.init(keyStore, pass); KeyManager[] km = kmFactory.getKeyManagers();
//Create trust manager:
TrustManagerFactory tmFactory = TrustManagerFactory.getInstance("SunX509");
tmFactory.init(keyStore); TrustManager[] tm = tmFactory.getTrustManagers();
//Create SSLContext with protocol:
SSLContext ctx = SSLContext.getInstance("TLSv1.2");
ctx.init(km, tm, null); return ctx;
}
Can anybody tell me what exactly is the cause of the error?. Am trying to establish an SSL connection to a server. But connection is always failing. After requesting for logs from the server guys, i can see javax.net.ssl.SSLHandshakeException: null cert chain on their error logs. i have been trying to research what this error is and what could cause it but to no avail. i would appreciate it if someone could give me a detailed explanation on what this error is and what could cause it.
Between here is my client code i am using to connect to the server
import java.io.*;
import java.net.*;
import java.security.*;
import java.util.Enumeration;
import javax.net.ssl.*;
public class SSLConnect {
public String MakeSSlCall(String meternum) {
String message = "";
FileWriter file = null;
try {
file = new FileWriter("C:\\SSLCERT\\ClientJavalog.txt");
} catch (Exception ee) {
message = ee.getMessage();
}
//writer = new BufferedWriter(file );
try {
file.write("KeyStore Generated\r\n");
KeyStore keystore = KeyStore.getInstance("JKS");
keystore.load(new FileInputStream("C:\\SSLCERT\\newclientkeystore"), "client".toCharArray());
file.write("KeyStore Generated\r\n");
Enumeration enumeration = keystore.aliases();
while (enumeration.hasMoreElements()) {
String alias = (String) enumeration.nextElement();
file.write("alias name: " + alias + "\r\n");
keystore.getCertificate(alias);
file.write(keystore.getCertificate(alias).toString() + "\r\n");
}
TrustManagerFactory tmf =TrustManagerFactory.getInstance("SunX509");
tmf.init(keystore);
file.write("KeyStore Stored\r\n");
SSLContext context = SSLContext.getInstance("SSL");
TrustManager[] trustManagers = tmf.getTrustManagers();
context.init(null, trustManagers, null);
SSLSocketFactory f = context.getSocketFactory();
file.write("About to Connect to Ontech\r\n");
SSLSocket c = (SSLSocket) f.createSocket("192.168.1.16", 4447);
file.write("Connection Established to 196.14.30.33 Port: 8462\r\n");
file.write("About to Start Handshake\r\n");
c.startHandshake();
file.write("Handshake Established\r\n");
file.flush();
file.close();
return "Connection Established";
}
catch (Exception e) {
try {
file.write("An Error Occured\r\n");
file.write(e.getMessage() + "\r\n");
file.flush();
file.close();
} catch (Exception eee) {
message = eee.getMessage();
}
return "Connection Failed";
}
}
}
My Keytool commands for generating a Truststore and importing the servers certificate and my own certificate
Keytool commands for creating my truststore
keytool -import -alias client -file client.cer -keystore MyKeystore -storepass mystore
keytool -import -alias server -file server.cer -keystore MyKeystore -storepass mystore
I am trying to create web socket server in Java which can accept connections from web clients (using Https). When open URL "https://localhost:8887" in chrome, Java application throws error: javax.net.ssl.SSLHandshakeException: no cipher suites in common. Below are the steps I have followed.
1) First I have created a keystore using following command (as mentioned # https://github.com/TooTallNate/Java-WebSocket/issues/160):
keytool -genkey -validity 3650 -keystore "keystore.jks" -storepass "storepassword" -keypass "keypassword" -alias "default" -dname "CN=127.0.0.1, OU=MyOrgUnit, O=MyOrg, L=MyCity, S=MyRegion, C=MyCountry"
2) Below is my Java web socket server creation code:
public class SocketServer extends WebSocketServer {
/** The web socket port number */
private static int PORT = 8887;
private static volatile SocketServer socketServer = null;
/**
* private constructor Creates a new WebSocketServer with the wildcard IP
* accepting all connections.
*/
private SocketServer() {
super(new InetSocketAddress(PORT));
}
/**
* Get singleton instance of Socket Server class
*/
public static SocketServer getInstance() {
if (socketServer == null) {
synchronized (SocketServer.class) {
// Double check
if (socketServer == null) {
WebSocketImpl.DEBUG = true;
socketServer = new SocketServer();
// load up the key store
String STORETYPE = "JKS";
String KEYSTORE = "keystore.jks";
String STOREPASSWORD = "storepassword";
String KEYPASSWORD = "keypassword";
try {
KeyStore ks = KeyStore.getInstance( STORETYPE );
File kf = new File( KEYSTORE );
ks.load( new FileInputStream( kf ), STOREPASSWORD.toCharArray() );
KeyManagerFactory kmf = KeyManagerFactory.getInstance( "SunX509" );
kmf.init( ks, KEYPASSWORD.toCharArray() );
TrustManagerFactory tmf = TrustManagerFactory.getInstance( "SunX509" );
tmf.init( ks );
SSLContext sslContext = null;
sslContext = SSLContext.getInstance( "TLS" );
sslContext.init( kmf.getKeyManagers(), tmf.getTrustManagers(), null );
socketServer.setWebSocketFactory( new DefaultSSLWebSocketServerFactory( sslContext ) );
} catch (Exception e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
socketServer.start();
}
}
}
return socketServer;
}
Please suggest what could be the issue?
Thanks in advance!