Merge branch 'master' of https://github.com/PlexDevelopment/Blackout

src/main/java/dev/plex/Blackout.java

@@ -2,10 +2,7 @@ package dev.plex;
 
 import dev.plex.listener.PlayerListener;
 import dev.plex.packet.PacketManager;
-import dev.plex.packet.impl.EndermanPotionPatch;
+import dev.plex.packet.impl.*;
-import dev.plex.packet.impl.KnowledgeBookPatch;
-import dev.plex.packet.impl.LecternPatch;
-import dev.plex.packet.impl.PaintingPatch;
 import lombok.Getter;
 import net.kyori.adventure.text.Component;
 import net.kyori.adventure.text.format.NamedTextColor;
@@ -41,6 +38,7 @@ public class Blackout extends JavaPlugin
         this.packetManager.registerListener(ServerboundUseItemOnPacket.class, new PaintingPatch());
         this.packetManager.registerListener(ServerboundUseItemOnPacket.class, new LecternPatch());
         this.packetManager.registerListener(ServerboundUseItemOnPacket.class, new KnowledgeBookPatch());
+        this.packetManager.registerListener(ServerboundSetCreativeModeSlotPacket.class, new SkullOwnerPatch());
         this.packetManager.registerListener(ClientboundUpdateMobEffectPacket.class, new EndermanPotionPatch());
 
         this.getServer().getPluginManager().registerEvents(new PlayerListener(), this);

src/main/java/dev/plex/packet/IPacketListener.java

@@ -5,6 +5,8 @@ import net.minecraft.network.protocol.Packet;
 import net.minecraft.world.entity.player.Player;
 import org.bukkit.event.Listener;
 
+import java.lang.reflect.Field;
+
 public interface IPacketListener<T extends Packet<?>> extends Listener
 {
     default boolean onReceive(Player player, T t)
@@ -16,4 +18,18 @@ public interface IPacketListener<T extends Packet<?>> extends Listener
     {
         return Blackout.getPlugin();
     }
+
+    default <J> J getFromField(Object object, String name)
+    {
+        try
+        {
+            Field field = object.getClass().getDeclaredField(name);
+            field.setAccessible(true);
+            return (J) field.get(object);
+        } catch (NoSuchFieldException | IllegalAccessException e)
+        {
+            e.printStackTrace();
+        }
+        return null;
+    }
 }

src/main/java/dev/plex/packet/impl/SkullOwnerPatch.java

@@ -0,0 +1,96 @@
+package dev.plex.packet.impl;
+
+import com.mojang.authlib.GameProfile;
+import dev.plex.Blackout;
+import dev.plex.packet.IPacketListener;
+import net.minecraft.nbt.CompoundTag;
+import net.minecraft.network.protocol.game.ServerboundSetCreativeModeSlotPacket;
+import net.minecraft.world.entity.player.Player;
+import net.minecraft.world.item.ItemStack;
+import org.bukkit.Material;
+import org.bukkit.craftbukkit.v1_18_R1.entity.CraftPlayer;
+import org.bukkit.craftbukkit.v1_18_R1.inventory.CraftItemStack;
+import org.bukkit.entity.EntityType;
+import org.bukkit.event.EventHandler;
+import org.bukkit.event.inventory.InventoryClickEvent;
+import org.bukkit.event.inventory.InventoryOpenEvent;
+import org.bukkit.event.inventory.InventoryType;
+import org.bukkit.inventory.meta.SkullMeta;
+
+import java.util.Arrays;
+
+public class SkullOwnerPatch implements IPacketListener<ServerboundSetCreativeModeSlotPacket>
+{
+    @EventHandler
+    public void onInventoryClick(InventoryClickEvent event)
+    {
+        org.bukkit.inventory.ItemStack bukkitItem = event.getCurrentItem();
+
+        if (bukkitItem == null) return;
+        if (event.getWhoClicked().getType() != EntityType.PLAYER) return;
+
+        checkItem(((CraftPlayer)event.getWhoClicked()).getHandle(), bukkitItem);
+    }
+
+    @EventHandler
+    public void onInventoryOpen(InventoryOpenEvent event)
+    {
+        if (event.getView().getType() == InventoryType.PLAYER)
+        {
+            Blackout.debug("Checking all items...");
+            Arrays.stream(event.getInventory().getContents()).forEach(item -> checkItem(((CraftPlayer)event.getPlayer()).getHandle(), item));
+        }
+    }
+
+    @Override
+    public boolean onReceive(Player player, ServerboundSetCreativeModeSlotPacket serverboundSetCreativeModeSlotPacket)
+    {
+        return checkItem(player, serverboundSetCreativeModeSlotPacket.getItem().getBukkitStack());
+    }
+
+    private boolean checkItem(Player player, org.bukkit.inventory.ItemStack bukkitItem)
+    {
+        Blackout.debug("Starting skull owner exploit patch...");
+        if (bukkitItem == null) return true;
+        ItemStack item = ((CraftItemStack)bukkitItem).handle;
+        if (item.getBukkitStack().getType() != Material.PLAYER_HEAD) return true;
+
+        SkullMeta meta = (SkullMeta) item.getBukkitStack().getItemMeta();
+        GameProfile profile = getFromField(meta, "profile");
+        Blackout.debug(String.valueOf(profile == null));
+        if (profile == null) return true;
+        if (profile.getName() == null && profile.getId() == null) return true;
+        if (profile.getName().isEmpty())
+        {
+            Blackout.debug("Patching invalid skull owner exploit!");
+            player.getInventory().removeItem(item);
+            return false;
+        }
+        if (!profile.getName().matches("\\p{Alpha}"))
+        {
+            Blackout.debug("Patching invalid skull owner exploit!");
+            player.getInventory().removeItem(item);
+            return false;
+        }
+        if (profile.getId().toString().isEmpty())
+        {
+            Blackout.debug("Patching invalid skull owner exploit!");
+            player.getInventory().removeItem(item);
+            return false;
+        }
+
+        if (!item.hasTag()) return true;
+
+        CompoundTag tag = item.getTag();
+        if (!tag.contains("SkullOwner")) return true;
+        String owner = tag.getString("SkullOwner");
+        if (!owner.matches("\\p{Alpha}"))
+        {
+            Blackout.debug("Patching invalid skull owner exploit!");
+            player.getInventory().removeItem(item);
+            return false;
+        }
+
+        return true;
+    }
+}