Added password authentication with OBS websocket server.

Author: sampie777

README.md

@@ -18,7 +18,6 @@ First include the library in your project using Maven:
 To get started just instantiate the OBSRemoteController:
 
 ```java
-
 OBSRemoteController controller = new OBSRemoteController("ws://localhost:4444", false);
 
 if (controller.isFailed()) { // Awaits response from OBS
@@ -37,6 +36,21 @@ controller.registerConnectCallback(response -> {
 	// Other requests...
 });
 ```
+
+#### Websocket server with authentication
+
+If your OBS websocket server is secured with a password, pass the password as a string to the controller:
+```java
+OBSRemoteController controller = new OBSRemoteController("ws://localhost:4444", false, "myPassword");
+```
+
+Catch any authentication errors by registering a callback for this:
+```java
+controller.registerConnectionFailedCallback(message -> {
+    System.err.println("Failed to connect: " + message);
+})
+```
+
 ---
 ## Supported requests and events 
 

src/main/java/net/twasi/obsremotejava/OBSCommunicator.java

@@ -9,6 +9,8 @@
 import net.twasi.obsremotejava.events.responses.SwitchScenesResponse;
 import net.twasi.obsremotejava.events.responses.TransitionBeginResponse;
 import net.twasi.obsremotejava.events.responses.TransitionEndResponse;
+import net.twasi.obsremotejava.requests.Authenticate.AuthenticateRequest;
+import net.twasi.obsremotejava.requests.Authenticate.AuthenticateResponse;
 import net.twasi.obsremotejava.requests.GetAuthRequired.GetAuthRequiredRequest;
 import net.twasi.obsremotejava.requests.GetAuthRequired.GetAuthRequiredResponse;
 import net.twasi.obsremotejava.requests.GetCurrentProfile.GetCurrentProfileRequest;
@@ -75,6 +77,10 @@
 import org.eclipse.jetty.websocket.api.annotations.OnWebSocketMessage;
 import org.eclipse.jetty.websocket.api.annotations.WebSocket;
 
+import java.nio.charset.StandardCharsets;
+import java.security.MessageDigest;
+import java.security.NoSuchAlgorithmException;
+import java.util.Base64;
 import java.util.HashMap;
 import java.util.Map;
 import java.util.concurrent.CountDownLatch;
@@ -84,6 +90,7 @@
 @WebSocket(maxTextMessageSize = 64 * 1024, maxIdleTime = 360000000)
 public class OBSCommunicator {
     private boolean debug;
+    private final String password;
     private final CountDownLatch closeLatch;
     public final Map<String, Class> messageTypes = new HashMap<>();
 
@@ -93,8 +100,9 @@ public class OBSCommunicator {
 
     private Callback onConnect;
     private Callback onDisconnect;
+    private StringCallback onConnectionFailed;
 
-    // Optinal callbacks
+    // Optional callbacks
     private Callback onReplayStarted;
     private Callback onReplayStarting;
     private Callback onReplayStopped;
@@ -106,9 +114,14 @@ public class OBSCommunicator {
 
     private GetVersionResponse versionInfo;
 
-    public OBSCommunicator(boolean debug) {
+    public OBSCommunicator(boolean debug, String password) {
         this.closeLatch = new CountDownLatch(1);
         this.debug = debug;
+        this.password = password;
+    }
+
+    public OBSCommunicator(boolean debug) {
+        this(debug, null);
     }
 
     public boolean awaitClose(int duration, TimeUnit unit) throws InterruptedException {
@@ -166,12 +179,23 @@ public void onMessage(String msg) {
                         GetAuthRequiredResponse authRequiredResponse = (GetAuthRequiredResponse) responseBase;
                         if (authRequiredResponse.isAuthRequired()) {
                             System.out.println("Authentication is required.");
-                            // TODO support authentication
+                            authenticateWithServer(authRequiredResponse.getChallenge(), authRequiredResponse.getSalt());
                         } else {
                             System.out.println("Authentication is not required. You're ready to go!");
                             this.onConnect.run(versionInfo);
                         }
                         break;
+
+                    case "AuthenticateResponse":
+                        AuthenticateResponse authenticateResponse = (AuthenticateResponse) responseBase;
+
+                        if ("ok".equals(authenticateResponse.getStatus())) {
+                            this.onConnect.run(versionInfo);
+                        } else {
+                            this.onConnectionFailed.run("Failed to authenticate with password. Error: " + authenticateResponse.getError());
+                        }
+
+                        break;
                     default:
                         if (callbacks.containsKey(type)) {
                             callbacks.get(type).run(responseBase);
@@ -233,6 +257,37 @@ public void onMessage(String msg) {
         }
     }
 
+    private void authenticateWithServer(String challenge, String salt) {
+        if (password == null) {
+            System.err.println("Authentication required by server but no password set for client");
+            this.onConnectionFailed.run("Authentication required by server but no password set for client");
+            return;
+        }
+
+        MessageDigest digest;
+        try {
+            digest = MessageDigest.getInstance("SHA-256");
+        } catch (NoSuchAlgorithmException e) {
+            System.err.println("Failed to perform password authentication with server");
+            e.printStackTrace();
+            this.onConnectionFailed.run("Failed to perform password authentication with server");
+            return;
+        }
+
+        // Generate authentication response secret
+        String secretString = password + salt;
+        byte[] secretHash = digest.digest(secretString.getBytes(StandardCharsets.UTF_8));
+        String encodedSecret = Base64.getEncoder().encodeToString(secretHash);
+
+        String authResponseString = encodedSecret + challenge;
+        byte[] authResponseHash = digest.digest(authResponseString.getBytes(StandardCharsets.UTF_8));
+        String authResponse = Base64.getEncoder().encodeToString(authResponseHash);
+
+        // Send authentication response secret to server
+        session.getRemote()
+                .sendStringByFuture(new Gson().toJson(new AuthenticateRequest(this, authResponse)));
+    }
+
     public void registerOnConnect(Callback onConnect) {
         this.onConnect = onConnect;
     }
@@ -241,6 +296,10 @@ public void registerOnDisconnect(Callback onDisconnect) {
         this.onDisconnect = onDisconnect;
     }
 
+    public void registerOnConnectionFailed(StringCallback onConnectionFailed) {
+        this.onConnectionFailed = onConnectionFailed;
+    }
+
     public void registerOnReplayStarted(Callback onReplayStarted) {
         this.onReplayStarted = onReplayStarted;
     }

src/main/java/net/twasi/obsremotejava/OBSRemoteController.java

@@ -18,17 +18,17 @@ public class OBSRemoteController {
 
     private boolean failed;
 
-    public OBSRemoteController(String address, boolean debug) {
+    public OBSRemoteController(String address, boolean debug, String password) {
         this.address = address;
-        communicator = new OBSCommunicator(debug);
+        communicator = new OBSCommunicator(debug, password);
         client = new WebSocketClient();
         try {
             client.start();
 
             URI uri = new URI(address);
             ClientUpgradeRequest request = new ClientUpgradeRequest();
             Future<Session> connection = client.connect(communicator, uri, request);
-            System.out.printf("Connecting to: %s%n", uri);
+            System.out.printf("Connecting to: %s%s%n", uri, (password != null ? " with password" : ""));
 
             try {
                 connection.get();
@@ -63,6 +63,10 @@ public void run() {
         }
     }
 
+    public OBSRemoteController(String address, boolean debug) {
+        this(address, debug, null);
+    }
+
     public boolean isFailed() {
         return failed;
     }
@@ -79,6 +83,10 @@ public void registerDisconnectCallback(Callback onDisconnect) {
         communicator.registerOnDisconnect(onDisconnect);
     }
 
+    public void registerConnectionFailedCallback(StringCallback onConnectionFailed) {
+        communicator.registerOnConnectionFailed(onConnectionFailed);
+    }
+
     public void registerReplayStartedCallback(Callback onReplayStarted) {
         communicator.registerOnReplayStarted(onReplayStarted);
     }

src/main/java/net/twasi/obsremotejava/StringCallback.java

@@ -0,0 +1,5 @@
+package net.twasi.obsremotejava;
+
+public interface StringCallback {
+    void run(String message);
+}

src/main/java/net/twasi/obsremotejava/requests/Authenticate/AuthenticateRequest.java

@@ -0,0 +1,21 @@
+package net.twasi.obsremotejava.requests.Authenticate;
+
+import net.twasi.obsremotejava.OBSCommunicator;
+import net.twasi.obsremotejava.requests.BaseRequest;
+import net.twasi.obsremotejava.requests.RequestType;
+
+public class AuthenticateRequest extends BaseRequest {
+    private String auth;
+
+    public AuthenticateRequest(OBSCommunicator com, String auth) {
+        super(RequestType.Authenticate);
+
+        this.auth = auth;
+
+        com.messageTypes.put(getMessageId(), AuthenticateResponse.class);
+    }
+
+    public String getAuth() {
+        return auth;
+    }
+}

src/main/java/net/twasi/obsremotejava/requests/Authenticate/AuthenticateResponse.java

@@ -0,0 +1,5 @@
+package net.twasi.obsremotejava.requests.Authenticate;
+
+import net.twasi.obsremotejava.requests.ResponseBase;
+
+public class AuthenticateResponse extends ResponseBase {}

src/main/java/net/twasi/obsremotejava/requests/RequestType.java

@@ -3,6 +3,7 @@
 public enum RequestType {
     GetVersion,
     GetAuthRequired,
+    Authenticate,
 
     SetCurrentScene,
     GetSceneList,