Implement proper handbook authentication (pt. 1)

src/main/java/emu/grasscutter/server/dispatch/DispatchClient.java

@@ -1,7 +1,5 @@
 package emu.grasscutter.server.dispatch;
 
-import static emu.grasscutter.config.Configuration.DISPATCH_INFO;
-
 import com.google.gson.JsonElement;
 import com.google.gson.JsonObject;
 import emu.grasscutter.Grasscutter;
@@ -12,21 +10,25 @@ import emu.grasscutter.utils.Crypto;
 import emu.grasscutter.utils.DispatchUtils;
 import emu.grasscutter.utils.JsonUtils;
 import emu.grasscutter.utils.objects.HandbookBody;
-import java.net.ConnectException;
-import java.net.URI;
-import java.nio.ByteBuffer;
-import java.nio.charset.StandardCharsets;
-import java.util.HashMap;
-import java.util.List;
-import java.util.Map;
-import java.util.function.BiConsumer;
-import java.util.function.Consumer;
 import lombok.Getter;
 import org.java_websocket.WebSocket;
 import org.java_websocket.client.WebSocketClient;
 import org.java_websocket.handshake.ServerHandshake;
 import org.slf4j.Logger;
 
+import java.net.ConnectException;
+import java.net.URI;
+import java.nio.ByteBuffer;
+import java.nio.charset.StandardCharsets;
+import java.util.ArrayList;
+import java.util.HashMap;
+import java.util.List;
+import java.util.Map;
+import java.util.function.BiConsumer;
+import java.util.function.Consumer;
+
+import static emu.grasscutter.config.Configuration.DISPATCH_INFO;
+
 public final class DispatchClient extends WebSocketClient implements IDispatcher {
     @Getter private final Logger logger = Grasscutter.getLogger();
     @Getter private final Map<Integer, BiConsumer<WebSocket, JsonElement>> handlers = new HashMap<>();
@@ -41,6 +43,7 @@ public final class DispatchClient extends WebSocketClient implements IDispatcher
 
         this.registerHandler(PacketIds.GachaHistoryReq, this::fetchGachaHistory);
         this.registerHandler(PacketIds.GmTalkReq, this::handleHandbookAction);
+        this.registerHandler(PacketIds.GetPlayerFieldsReq, this::fetchPlayerFields);
     }
 
     /**
@@ -105,6 +108,32 @@ public final class DispatchClient extends WebSocketClient implements IDispatcher
         this.sendMessage(PacketIds.GmTalkRsp, response);
     }
 
+    /**
+     * Fetches the fields of an online player.
+     *
+     * @param socket The socket the packet was received from.
+     * @param object The packet data.
+     */
+    private void fetchPlayerFields(WebSocket socket, JsonElement object) {
+        var message = IDispatcher.decode(object);
+        var playerId = message.get("playerId").getAsInt();
+        var fieldsRaw = message.get("fields").getAsJsonArray();
+
+        // Get the player with the specified ID.
+        var player = Grasscutter.getGameServer().getPlayerByUid(playerId, true);
+        if (player == null) return;
+
+        // Convert the fields array.
+        var fieldsList = new ArrayList<String>();
+        for (var field : fieldsRaw)
+            fieldsList.add(field.getAsString());
+        var fields = fieldsList.toArray(new String[0]);
+
+        // Return the response object.
+        this.sendMessage(PacketIds.GetPlayerFieldsRsp,
+            DispatchUtils.getPlayerFields(playerId, fields));
+    }
+
     /**
      * Sends a serialized encrypted message to the server.
      *

src/main/java/emu/grasscutter/server/dispatch/DispatchServer.java

@@ -1,12 +1,16 @@
 package emu.grasscutter.server.dispatch;
 
-import static emu.grasscutter.config.Configuration.DISPATCH_INFO;
-
 import com.google.gson.JsonElement;
 import com.google.gson.JsonObject;
 import emu.grasscutter.Grasscutter;
 import emu.grasscutter.database.DatabaseHelper;
 import emu.grasscutter.utils.Crypto;
+import lombok.Getter;
+import org.java_websocket.WebSocket;
+import org.java_websocket.handshake.ClientHandshake;
+import org.java_websocket.server.WebSocketServer;
+import org.slf4j.Logger;
+
 import java.net.InetSocketAddress;
 import java.nio.ByteBuffer;
 import java.nio.charset.StandardCharsets;
@@ -15,11 +19,8 @@ import java.util.List;
 import java.util.Map;
 import java.util.function.BiConsumer;
 import java.util.function.Consumer;
-import lombok.Getter;
-import org.java_websocket.WebSocket;
-import org.java_websocket.handshake.ClientHandshake;
-import org.java_websocket.server.WebSocketServer;
-import org.slf4j.Logger;
+
+import static emu.grasscutter.config.Configuration.DISPATCH_INFO;
 
 /* Internal communications server. */
 public final class DispatchServer extends WebSocketServer implements IDispatcher {
@@ -39,6 +40,7 @@ public final class DispatchServer extends WebSocketServer implements IDispatcher
 
         this.registerHandler(PacketIds.LoginNotify, this::handleLogin);
         this.registerHandler(PacketIds.TokenValidateReq, this::validateToken);
+        this.registerHandler(PacketIds.GetAccountReq, this::fetchAccount);
     }
 
     /**
@@ -84,6 +86,23 @@ public final class DispatchServer extends WebSocketServer implements IDispatcher
         this.sendMessage(socket, PacketIds.TokenValidateRsp, response);
     }
 
+    /**
+     * Fetches an account by its ID.
+     *
+     * @param socket The socket the packet was received from.
+     * @param object The packet data.
+     */
+    private void fetchAccount(WebSocket socket, JsonElement object) {
+        var message = IDispatcher.decode(object);
+        var accountId = message.get("accountId").getAsString();
+
+        // Get the account from the database.
+        var account = DatabaseHelper.getAccountById(accountId);
+        // Send the account.
+        this.sendMessage(socket, PacketIds.GetAccountRsp,
+            JSON.toJsonTree(account));
+    }
+
     /**
      * Broadcasts an encrypted message to all connected clients.
      *

src/main/java/emu/grasscutter/server/dispatch/IDispatcher.java

@@ -1,21 +1,25 @@
 package emu.grasscutter.server.dispatch;
 
-import static emu.grasscutter.config.Configuration.DISPATCH_INFO;
-
 import com.google.gson.Gson;
 import com.google.gson.GsonBuilder;
 import com.google.gson.JsonElement;
 import com.google.gson.JsonObject;
 import emu.grasscutter.utils.Crypto;
 import emu.grasscutter.utils.JsonAdapters.ByteArrayAdapter;
+import org.java_websocket.WebSocket;
+import org.slf4j.Logger;
+
 import java.nio.charset.StandardCharsets;
 import java.util.LinkedList;
 import java.util.List;
 import java.util.Map;
+import java.util.concurrent.CompletableFuture;
+import java.util.concurrent.TimeUnit;
 import java.util.function.BiConsumer;
 import java.util.function.Consumer;
-import org.java_websocket.WebSocket;
-import org.slf4j.Logger;
+import java.util.function.Function;
+
+import static emu.grasscutter.config.Configuration.DISPATCH_INFO;
 
 public interface IDispatcher {
     Gson JSON =
@@ -24,6 +28,9 @@ public interface IDispatcher {
                     .registerTypeAdapter(byte[].class, new ByteArrayAdapter())
                     .create();
 
+    Function<JsonElement, JsonObject> DEFAULT_PARSER = (packet) ->
+        IDispatcher.decode(packet, JsonObject.class);
+
     /**
      * Decodes an escaped JSON message.
      *
@@ -61,6 +68,75 @@ public interface IDispatcher {
         }
     }
 
+    /**
+     * Waits for a request from the other server to be fulfilled.
+     *
+     * @param request The request data.
+     * @param requestId The request packet ID.
+     * @param responseId the response packet ID.
+     * @param parser The parser for the response data.
+     * @return The fulfilled data, or null.
+     * @param <T> The type of data to be returned.
+     */
+    default <T> T await(JsonObject request, int requestId, int responseId,
+                        Function<JsonElement, T> parser) {
+        // Perform the setup for the request.
+        var future = this.async(request, requestId, responseId, parser);
+
+        try {
+            // Try to return the value.
+            return future.get(5L, TimeUnit.SECONDS);
+        } catch (Exception ignored) {
+            return null;
+        }
+    }
+
+    /**
+     * Registers a callback for a packet to be received.
+     * Sends a packet with the provided request.
+     *
+     * @param request The request object.
+     * @param requestId The packet ID of the request packet.
+     * @param responseId The packet ID of the response packet.
+     * @return A promise containing the parsed JSON data.
+     */
+    default CompletableFuture<JsonObject> async(JsonObject request, int requestId, int responseId) {
+        return this.async(request, requestId, responseId, DEFAULT_PARSER);
+    }
+
+    /**
+     * Registers a callback for a packet to be received.
+     * Sends a packet with the provided request.
+     *
+     * @param request The request object.
+     * @param requestId The packet ID of the request packet.
+     * @param responseId The packet ID of the response packet.
+     * @param parser The parser for the received data.
+     * @return A promise containing the parsed JSON data.
+     */
+    default <T> CompletableFuture<T> async(
+        JsonObject request, int requestId, int responseId,
+        Function<JsonElement, T> parser
+    ) {
+        // Create the future.
+        var future = new CompletableFuture<T>();
+        // Listen for the response.
+        this.registerCallback(responseId, packet ->
+            future.complete(parser.apply(packet)));
+        // Broadcast the packet.
+        this.sendMessage(requestId, request);
+
+        return future;
+    }
+
+    /**
+     * Internally used method to broadcast a packet.
+     *
+     * @param packetId The packet ID.
+     * @param message The packet data.
+     */
+    void sendMessage(int packetId, Object message);
+
     /**
      * Decodes a message from the client.
      *

src/main/java/emu/grasscutter/server/dispatch/PacketIds.java

@@ -11,4 +11,8 @@ public interface PacketIds {
     int GachaHistoryRsp = 5;
     int GmTalkReq = PacketOpcodes.GmTalkReq;
     int GmTalkRsp = PacketOpcodes.GmTalkRsp;
+    int GetAccountReq = 6;
+    int GetAccountRsp = 7;
+    int GetPlayerFieldsReq = 8;
+    int GetPlayerFieldsRsp = 9;
 }

src/main/java/emu/grasscutter/server/http/HttpServer.java

@@ -5,6 +5,7 @@ import emu.grasscutter.Grasscutter.ServerDebugMode;
 import emu.grasscutter.utils.FileUtils;
 import io.javalin.Javalin;
 import io.javalin.http.ContentType;
+import io.javalin.json.JavalinGson;
 import org.eclipse.jetty.server.Server;
 import org.eclipse.jetty.server.ServerConnector;
 import org.eclipse.jetty.util.ssl.SslContextFactory;
@@ -57,6 +58,9 @@ public final class HttpServer {
             if (DISPATCH_INFO.logRequests == ServerDebugMode.ALL)
                 config.plugins.enableDevLogging();
 
+            // Set the JSON mapper.
+            config.jsonMapper(new JavalinGson());
+
             // Static files should be added like this https://javalin.io/documentation#static-files
         });
 

src/main/java/emu/grasscutter/server/http/documentation/HandbookHandler.java

@@ -1,15 +1,18 @@
 package emu.grasscutter.server.http.documentation;
 
-import static emu.grasscutter.config.Configuration.HANDBOOK;
-
+import emu.grasscutter.Grasscutter;
+import emu.grasscutter.auth.AuthenticationSystem.AuthenticationRequest;
 import emu.grasscutter.server.http.Router;
 import emu.grasscutter.utils.DispatchUtils;
 import emu.grasscutter.utils.FileUtils;
 import emu.grasscutter.utils.objects.HandbookBody;
 import emu.grasscutter.utils.objects.HandbookBody.Action;
 import io.javalin.Javalin;
+import io.javalin.http.ContentType;
 import io.javalin.http.Context;
 
+import static emu.grasscutter.config.Configuration.HANDBOOK;
+
 /** Handles requests for the new GM Handbook. */
 public final class HandbookHandler implements Router {
     private final byte[] handbook;
@@ -20,7 +23,7 @@ public final class HandbookHandler implements Router {
      * found.
      */
     public HandbookHandler() {
-        this.handbook = FileUtils.readResource("/handbook.html");
+        this.handbook = FileUtils.readResource("/html/handbook.html");
         this.serve = HANDBOOK.enable && this.handbook.length > 0;
     }
 
@@ -30,6 +33,9 @@ public final class HandbookHandler implements Router {
 
         // The handbook content. (built from src/handbook)
         javalin.get("/handbook", this::serveHandbook);
+        // The handbook authentication page.
+        javalin.get("/handbook/authenticate", this::authenticate);
+        javalin.post("/handbook/authenticate", this::performAuthentication);
 
         // Handbook control routes.
         javalin.post("/handbook/avatar", this::grantAvatar);
@@ -59,6 +65,49 @@ public final class HandbookHandler implements Router {
         }
     }
 
+    /**
+     * Serves the handbook authentication page.
+     *
+     * @route GET /handbook/authenticate
+     * @param ctx The Javalin request context.
+     */
+    private void authenticate(Context ctx) {
+        if (!this.serve) {
+            ctx.status(500).result("Handbook not found.");
+        } else {
+            // Pass the request to the authenticator.
+            Grasscutter.getAuthenticationSystem()
+                .getHandbookAuthenticator().presentPage(
+                    AuthenticationRequest.builder().context(ctx).build());
+        }
+    }
+
+    /**
+     * Performs authentication for the handbook.
+     *
+     * @route POST /handbook/authenticate
+     * @param ctx The Javalin request context.
+     */
+    private void performAuthentication(Context ctx) {
+        if (!this.serve) {
+            ctx.status(500).result("Handbook not found.");
+        } else {
+            // Pass the request to the authenticator.
+            var result = Grasscutter.getAuthenticationSystem()
+                .getHandbookAuthenticator().authenticate(
+                    AuthenticationRequest.builder().context(ctx).build());
+            if (result == null) {
+                ctx.status(500).result("Authentication failed.");
+            } else {
+                ctx
+                    .status(result.getStatus())
+                    .result(result.getBody())
+                    .contentType(result.getBody().contains("html") ?
+                        ContentType.TEXT_HTML : ContentType.TEXT_PLAIN);
+            }
+        }
+    }
+
     /**
      * Grants the avatar to the user.
      *