Implement server time spoofer

src/main/java/emu/lunarcore/Config.java

@@ -1,5 +1,6 @@
 package emu.lunarcore;
 
+import java.util.Date;
 import java.util.List;
 import java.util.Set;
 
@@ -22,6 +23,7 @@ public class Config {
     public GameServerConfig gameServer = new GameServerConfig(23301);
     
     public ServerOptions serverOptions = new ServerOptions();
+    public ServerTime serverTime = new ServerTime();
     public ServerRates serverRates = new ServerRates();
     public LogOptions logOptions = new LogOptions();
     public DownloadData downloadData = new DownloadData();
@@ -107,6 +109,12 @@ public class Config {
         }
     }
     
+    @Getter 
+    public static class ServerTime {
+        public boolean spoofTime = false;
+        public Date spoofDate = new Date(1705276800000L); // January 15, 2024 12:00:00 AM (GMT)
+    }
+    
     @Getter
     public static class ServerOptions {
         public boolean autoCreateAccount = true;

src/main/java/emu/lunarcore/LunarCore.java

@@ -44,6 +44,8 @@ public class LunarCore {
     private static LineReaderImpl reader;
     @Getter private static boolean usingDumbTerminal;
     
+    private static long timeOffset = 0;
+
     static {
         // Setup console reader
         try {
@@ -58,6 +60,7 @@ public class LunarCore {
 
         // Load config
         LunarCore.loadConfig();
+        LunarCore.updateServerTimeOffset();
     }
 
     public static void main(String[] args) {
@@ -195,7 +198,12 @@ public class LunarCore {
 
     public static void saveConfig() {
         try (FileWriter file = new FileWriter(configFile)) {
-            Gson gson = new GsonBuilder().setPrettyPrinting().serializeNulls().create();
+            Gson gson = new GsonBuilder()
+                    .setDateFormat("dd-MM-yyyy hh:mm:ss")
+                    .setPrettyPrinting()
+                    .serializeNulls()
+                    .create();
+            
             file.write(gson.toJson(config));
         } catch (Exception e) {
             getLogger().error("Config save error");
@@ -242,6 +250,22 @@ public class LunarCore {
         }
     }
     
+    /**
+     * Returns the current server's time in milliseconds to send to the client. Can be used to spoof server time.
+     */
+    public static long currentServerTime() {
+        return System.currentTimeMillis() + timeOffset;
+    }
+    
+    private static void updateServerTimeOffset() {
+        var timeOptions = LunarCore.getConfig().getServerTime();
+        if (timeOptions.isSpoofTime() && timeOptions.getSpoofDate() != null) {
+            timeOffset = timeOptions.getSpoofDate().getTime() - System.currentTimeMillis();
+        } else {
+            timeOffset = 0;
+        }
+    }
+
     // Server console
 
     private static void startConsole() {

src/main/java/emu/lunarcore/server/packet/send/PacketPlayerHeartBeatScRsp.java

@@ -1,5 +1,6 @@
 package emu.lunarcore.server.packet.send;
 
+import emu.lunarcore.LunarCore;
 import emu.lunarcore.proto.PlayerHeartbeatScRspOuterClass.PlayerHeartbeatScRsp;
 import emu.lunarcore.server.packet.BasePacket;
 import emu.lunarcore.server.packet.CmdId;
@@ -11,7 +12,7 @@ public class PacketPlayerHeartBeatScRsp extends BasePacket {
 
         var data = PlayerHeartbeatScRsp.newInstance()
                 .setClientTimeMs(clientTime)
-                .setServerTimeMs(System.currentTimeMillis());
+                .setServerTimeMs(LunarCore.currentServerTime());
 
         this.setData(data);
     }

src/main/java/emu/lunarcore/server/packet/send/PacketPlayerLoginScRsp.java

@@ -1,6 +1,7 @@
 package emu.lunarcore.server.packet.send;
 
 import emu.lunarcore.GameConstants;
+import emu.lunarcore.LunarCore;
 import emu.lunarcore.proto.PlayerLoginScRspOuterClass.PlayerLoginScRsp;
 import emu.lunarcore.server.game.GameSession;
 import emu.lunarcore.server.packet.BasePacket;
@@ -14,7 +15,7 @@ public class PacketPlayerLoginScRsp extends BasePacket {
         var data = PlayerLoginScRsp.newInstance()
                 .setBasicInfo(session.getPlayer().toProto())
                 .setCurTimezone(GameConstants.CURRENT_TIMEZONE)
-                .setServerTimestampMs(System.currentTimeMillis())
+                .setServerTimestampMs(LunarCore.currentServerTime())
                 .setStamina(session.getPlayer().getStamina());
 
         this.setData(data);

src/main/java/emu/lunarcore/util/JsonUtils.java

@@ -13,7 +13,7 @@ import com.google.gson.reflect.TypeToken;
 import emu.lunarcore.LunarCore;
 
 public class JsonUtils {
-    private static final Gson gson = new GsonBuilder().setPrettyPrinting().create();
+    private static final Gson gson = new GsonBuilder().setDateFormat("dd-MM-yyyy hh:mm:ss").setPrettyPrinting().create();
     private static final Gson gsonCompact = new GsonBuilder().create();
 
     public static Gson getGsonFactory() {