valiate tp packets (#128)

* validate tp packets

Signed-off-by: Glease <4586901+Glease@users.noreply.github.com>

* spotless

Signed-off-by: Glease <4586901+Glease@users.noreply.github.com>

---------

Signed-off-by: Glease <4586901+Glease@users.noreply.github.com>

src/main/java/crazypants/enderio/api/teleport/IItemOfTravel.java

@@ -4,10 +4,20 @@ import net.minecraft.entity.player.EntityPlayer;
 import net.minecraft.item.ItemStack;
 
 import cofh.api.energy.IEnergyContainerItem;
+import crazypants.enderio.config.Config;
 
 public interface IItemOfTravel extends IEnergyContainerItem {
 
     boolean isActive(EntityPlayer ep, ItemStack equipped);
 
     void extractInternal(ItemStack equipped, int power);
+
+    /**
+     * @param equipped player who is currently holding this item. caller will ensure the item held has your Item as item
+     *                 type
+     * @return -1 if method not supported, or max(can extract, power), e.g. 0 if item is empty.
+     */
+    default int canExtractInternal(ItemStack equipped, int power) {
+        return Config.strictTPItemChecking ? 0 : -1;
+    }
 }

src/main/java/crazypants/enderio/config/Config.java

@@ -563,6 +563,8 @@ public final class Config {
     public static float inventoryPanelExtractCostPerItem = 12.0f;
     public static float inventoryPanelExtractCostPerOperation = 32.0f;
 
+    public static boolean strictTPItemChecking = true;
+
     public static void load(FMLPreInitializationEvent event) {
         PacketHandler.INSTANCE
                 .registerMessage(PacketConfigSync.class, PacketConfigSync.class, PacketHandler.nextID(), Side.CLIENT);
@@ -2884,6 +2886,12 @@ public final class Config {
                 0.0f,
                 10000.0f,
                 "Internal power used per extract operation (independent of stack size)");
+        strictTPItemChecking = config.get(
+                sectionMisc.name,
+                "strictTPItemChecking",
+                strictTPItemChecking,
+                "If true, turn on strict checking of item energy checking. This might cause traveling tools from third party mods to fire fake security warnings on server side and not function correctly.")
+                .getBoolean(strictTPItemChecking);
     }
 
     public static void checkYetaAccess() {

src/main/java/crazypants/enderio/item/darksteel/ItemDarkSteelPickaxe.java

@@ -331,6 +331,11 @@ public class ItemDarkSteelPickaxe extends ItemPickaxe
         extractEnergy(equipped, power, false);
     }
 
+    @Override
+    public int canExtractInternal(ItemStack equipped, int power) {
+        return extractEnergy(equipped, power, true);
+    }
+
     private boolean isTravelUpgradeActive(EntityPlayer ep, ItemStack equipped) {
         return isEquipped(ep) && ep.isSneaking() && TravelUpgrade.loadFromItem(equipped) != null;
     }

src/main/java/crazypants/enderio/item/darksteel/ItemDarkSteelSword.java

@@ -394,6 +394,11 @@ public class ItemDarkSteelSword extends ItemSword
         extractEnergy(equipped, power, false);
     }
 
+    @Override
+    public int canExtractInternal(ItemStack equipped, int power) {
+        return extractEnergy(equipped, power, true);
+    }
+
     private boolean isTravelUpgradeActive(EntityPlayer ep, ItemStack equipped) {
         return isEquipped(ep) && ep.isSneaking() && TravelUpgrade.loadFromItem(equipped) != null;
     }

src/main/java/crazypants/enderio/teleport/ItemTeleportStaff.java

@@ -84,6 +84,11 @@ public class ItemTeleportStaff extends ItemTravelStaff {
         // Do nothing, as we have infinite energy.
     }
 
+    @Override
+    public int canExtractInternal(ItemStack equipped, int power) {
+        return power;
+    }
+
     @Override
     @SideOnly(Side.CLIENT)
     public void getSubItems(Item item, CreativeTabs par2CreativeTabs, List par3List) {

src/main/java/crazypants/enderio/teleport/ItemTravelStaff.java

@@ -132,6 +132,11 @@ public class ItemTravelStaff extends ItemEnergyContainer implements IItemOfTrave
         setEnergy(item, res);
     }
 
+    @Override
+    public int canExtractInternal(ItemStack equipped, int power) {
+        return Math.min(getEnergyStored(equipped), power);
+    }
+
     void setEnergy(ItemStack container, int energy) {
         if (container.stackTagCompound == null) {
             container.stackTagCompound = new NBTTagCompound();

src/main/java/crazypants/enderio/teleport/TravelController.java

@@ -111,6 +111,47 @@ public class TravelController {
         }
     }
 
+    public boolean validatePacketTravelEvent(EntityPlayerMP toTp, int x, int y, int z, int powerUse,
+            boolean conserveMotion, TravelSource source) {
+        BlockCoord target = new BlockCoord(x, y, z);
+        double dist = getDistanceSquared(toTp, target);
+        // allow 15% overshoot to account for rounding
+        if (dist * 100 > source.getMaxDistanceTravelledSq() * 115) return false;
+        if (powerUse < getRequiredPower(toTp, source, target)) return false;
+        ItemStack equippedItem = toTp.getCurrentEquippedItem();
+        switch (source) {
+            case TELEPAD:
+                // this source is invalid for this type of packet
+                return false;
+            case BLOCK:
+                // this source is only triggered when player is on any active travel anchor
+                BlockCoord on = getActiveTravelBlock(toTp);
+                if (on == null) return false;
+                // target must be a valid selectedCoord
+                // selectedCoord can either be a block right above/below when the player is on anchor...
+                if (on.x == x && on.z == z) return true;
+                // or another anchor
+                TileEntity maybeAnchor = target.getTileEntity(toTp.worldObj);
+                if (!(maybeAnchor instanceof ITravelAccessable)) return false;
+                ITravelAccessable anchor = (ITravelAccessable) maybeAnchor;
+                return anchor.canBlockBeAccessed(toTp) || !isValidTarget(toTp, target, TravelSource.BLOCK);
+            case STAFF:
+            case STAFF_BLINK:
+                if (equippedItem == null || !(equippedItem.getItem() instanceof IItemOfTravel)) return false;
+                if (!((IItemOfTravel) equippedItem.getItem()).isActive(toTp, equippedItem)) return false;
+                int energy = ((IItemOfTravel) equippedItem.getItem()).canExtractInternal(equippedItem, powerUse);
+                return energy == -1 || energy == powerUse;
+            case TELEPORT_STAFF_BLINK:
+            case TELEPORT_STAFF:
+                // tp staff is creative version of traveling staff
+                // no energy check or anything else needed
+                // but the player must actually be equipped with one of these
+                return equippedItem != null && equippedItem.getItem() instanceof ItemTeleportStaff;
+            default:
+                throw new AssertionError("unidentified travel source");
+        }
+    }
+
     public void addBlockToBlinkBlackList(String blockName) {
         blackList.add(new UniqueIdentifier(blockName));
     }
@@ -733,35 +774,41 @@ public class TravelController {
                 && y <= 255; i++, y += direction) {
 
             // Circumvents the raytracing used to find candidates on the y axis
-            TileEntity selectedBlock = world.getTileEntity(currentBlock.x, y, currentBlock.z);
-
-            if (selectedBlock instanceof ITravelAccessable) {
-                ITravelAccessable travelBlock = (ITravelAccessable) selectedBlock;
-                BlockCoord targetBlock = new BlockCoord(currentBlock.x, y, currentBlock.z);
-
-                if (Config.travelAnchorSkipWarning) {
-                    if (travelBlock.getRequiresPassword(player)) {
-                        showMessage(player, new ChatComponentTranslation("enderio.gui.travelAccessable.skipLocked"));
-                    }
-
-                    if (travelBlock.getAccessMode() == ITravelAccessable.AccessMode.PRIVATE
-                            && !travelBlock.canUiBeAccessed(player)) {
-                        showMessage(player, new ChatComponentTranslation("enderio.gui.travelAccessable.skipPrivate"));
-                    }
-                    if (!isValidTarget(player, targetBlock, TravelSource.BLOCK)) {
-                        showMessage(
-                                player,
-                                new ChatComponentTranslation("enderio.gui.travelAccessable.skipObstructed"));
-                    }
-                }
-                if (travelBlock.canBlockBeAccessed(player) && isValidTarget(player, targetBlock, TravelSource.BLOCK)) {
-                    selectedCoord = targetBlock;
-                    return;
-                }
+            BlockCoord targetBlock = getValidVerticalTarget(player, currentBlock, world, y);
+            if (targetBlock != null) {
+                selectedCoord = targetBlock;
+                return;
             }
         }
     }
 
+    private BlockCoord getValidVerticalTarget(EntityPlayer player, BlockCoord currentBlock, World world, int y) {
+        TileEntity selectedBlock = world.getTileEntity(currentBlock.x, y, currentBlock.z);
+
+        if (selectedBlock instanceof ITravelAccessable) {
+            ITravelAccessable travelBlock = (ITravelAccessable) selectedBlock;
+            BlockCoord targetBlock = new BlockCoord(currentBlock.x, y, currentBlock.z);
+
+            if (Config.travelAnchorSkipWarning) {
+                if (travelBlock.getRequiresPassword(player)) {
+                    showMessage(player, new ChatComponentTranslation("enderio.gui.travelAccessable.skipLocked"));
+                }
+
+                if (travelBlock.getAccessMode() == ITravelAccessable.AccessMode.PRIVATE
+                        && !travelBlock.canUiBeAccessed(player)) {
+                    showMessage(player, new ChatComponentTranslation("enderio.gui.travelAccessable.skipPrivate"));
+                }
+                if (!isValidTarget(player, targetBlock, TravelSource.BLOCK)) {
+                    showMessage(player, new ChatComponentTranslation("enderio.gui.travelAccessable.skipObstructed"));
+                }
+            }
+            if (travelBlock.canBlockBeAccessed(player) && isValidTarget(player, targetBlock, TravelSource.BLOCK)) {
+                return targetBlock;
+            }
+        }
+        return null;
+    }
+
     @SideOnly(Side.CLIENT)
     private void updateSelectedTarget(EntityPlayer player) {
         selectedCoord = null;
@@ -923,19 +970,16 @@ public class TravelController {
         return true;
     }
 
-    @SideOnly(Side.CLIENT)
     private BlockCoord getActiveTravelBlock(EntityPlayer player) {
-        World world = Minecraft.getMinecraft().theWorld;
-        if (world != null && player != null) {
-            int x = MathHelper.floor_double(player.posX);
-            int y = MathHelper.floor_double(player.boundingBox.minY) - 1;
-            int z = MathHelper.floor_double(player.posZ);
-            TileEntity tileEntity = world.getTileEntity(x, y, z);
-            if (tileEntity instanceof ITravelAccessable) {
-                if (((ITravelAccessable) tileEntity).isTravelSource()) {
-                    return new BlockCoord(x, y, z);
-                }
-            }
+        if (player == null) return null;
+        World world = player.worldObj;
+        if (world == null) return null;
+        int x = MathHelper.floor_double(player.posX);
+        int y = MathHelper.floor_double(player.boundingBox.minY) - 1;
+        int z = MathHelper.floor_double(player.posZ);
+        TileEntity tileEntity = world.getTileEntity(x, y, z);
+        if (tileEntity instanceof ITravelAccessable && ((ITravelAccessable) tileEntity).isTravelSource()) {
+            return new BlockCoord(x, y, z);
         }
         return null;
     }

src/main/java/crazypants/enderio/teleport/packet/PacketLongDistanceTravelEvent.java

@@ -16,9 +16,11 @@ import com.enderio.core.common.vecmath.Vector3d;
 import cpw.mods.fml.common.network.simpleimpl.IMessage;
 import cpw.mods.fml.common.network.simpleimpl.IMessageHandler;
 import cpw.mods.fml.common.network.simpleimpl.MessageContext;
+import crazypants.enderio.Log;
 import crazypants.enderio.api.teleport.IItemOfTravel;
 import crazypants.enderio.api.teleport.TeleportEntityEvent;
 import crazypants.enderio.api.teleport.TravelSource;
+import crazypants.enderio.teleport.ItemTeleportStaff;
 import crazypants.enderio.teleport.TravelController;
 import io.netty.buffer.ByteBuf;
 
@@ -53,16 +55,50 @@ public class PacketLongDistanceTravelEvent
 
     @Override
     public IMessage onMessage(PacketLongDistanceTravelEvent message, MessageContext ctx) {
-        Entity toTp = message.entityId == -1 ? ctx.getServerHandler().playerEntity
-                : ctx.getServerHandler().playerEntity.worldObj.getEntityByID(message.entityId);
+        if (message.entityId != -1) {
+            // after checking the code base, this type of packet won't be sent at all,
+            // so we can assume this to be an attempt to hack
+            Log.LOGGER.warn(
+                    Log.securityMarker,
+                    "Player {} tried to illegally tp other entity {}.",
+                    ctx.getServerHandler().playerEntity.getGameProfile(),
+                    message.entityId);
+            return null;
+        }
+        EntityPlayerMP toTp = ctx.getServerHandler().playerEntity;
 
         TravelSource source = TravelSource.values()[message.source];
 
+        if (!validate(toTp, source)) {
+            Log.LOGGER.warn(
+                    Log.securityMarker,
+                    "Player {} tried to tp without valid prereq.",
+                    ctx.getServerHandler().playerEntity.getGameProfile());
+            return null;
+        }
+
         doServerTeleport(toTp, message.conserveMotion, source);
 
         return null;
     }
 
+    private static boolean validate(EntityPlayerMP toTp, TravelSource source) {
+        ItemStack equippedItem = toTp.getCurrentEquippedItem();
+        switch (source) {
+            case STAFF:
+                return equippedItem != null && equippedItem.getItem() instanceof IItemOfTravel
+                        && ((IItemOfTravel) equippedItem.getItem()).isActive(toTp, equippedItem);
+            case TELEPORT_STAFF:
+                // tp staff is creative version of traveling staff
+                // no energy check or anything else needed
+                // but the player must actually be equipped with one of these
+                return equippedItem != null && equippedItem.getItem() instanceof ItemTeleportStaff;
+            default:
+                // all other types are not allowed
+                return false;
+        }
+    }
+
     public static boolean doServerTeleport(Entity toTp, boolean conserveMotion, TravelSource source) {
         EntityPlayer player = toTp instanceof EntityPlayer ? (EntityPlayer) toTp : null;
         Optional<BlockCoord> travelDestination = TravelController.instance.findTravelDestination(player, source);
@@ -77,6 +113,14 @@ public class PacketLongDistanceTravelEvent
         if (powerUse < 0) {
             return false;
         }
+        if (player != null && player.getCurrentEquippedItem() != null
+                && player.getCurrentEquippedItem().getItem() instanceof IItemOfTravel) {
+            int used = ((IItemOfTravel) player.getCurrentEquippedItem().getItem())
+                    .canExtractInternal(player.getCurrentEquippedItem(), powerUse);
+            if (used != -1 && used != powerUse) {
+                return false;
+            }
+        }
 
         TeleportEntityEvent evt = new TeleportEntityEvent(toTp, source, x, y, z);
         if (MinecraftForge.EVENT_BUS.post(evt)) {

src/main/java/crazypants/enderio/teleport/packet/PacketTravelEvent.java

@@ -13,9 +13,11 @@ import com.enderio.core.common.vecmath.Vector3d;
 import cpw.mods.fml.common.network.simpleimpl.IMessage;
 import cpw.mods.fml.common.network.simpleimpl.IMessageHandler;
 import cpw.mods.fml.common.network.simpleimpl.MessageContext;
+import crazypants.enderio.Log;
 import crazypants.enderio.api.teleport.IItemOfTravel;
 import crazypants.enderio.api.teleport.TeleportEntityEvent;
 import crazypants.enderio.api.teleport.TravelSource;
+import crazypants.enderio.teleport.TravelController;
 import io.netty.buffer.ByteBuf;
 
 public class PacketTravelEvent implements IMessage, IMessageHandler<PacketTravelEvent, IMessage> {
@@ -65,13 +67,31 @@ public class PacketTravelEvent implements IMessage, IMessageHandler<PacketTravel
 
     @Override
     public IMessage onMessage(PacketTravelEvent message, MessageContext ctx) {
-        Entity toTp = message.entityId == -1 ? ctx.getServerHandler().playerEntity
-                : ctx.getServerHandler().playerEntity.worldObj.getEntityByID(message.entityId);
+        if (message.entityId != -1) {
+            // after checking the code base, this type of packet won't be sent at all,
+            // so we can assume this to be an attempt to hack
+            Log.LOGGER.warn(
+                    Log.securityMarker,
+                    "Player {} tried to illegally tp other entity {}.",
+                    ctx.getServerHandler().playerEntity.getGameProfile(),
+                    message.entityId);
+            return null;
+        }
+        EntityPlayerMP toTp = ctx.getServerHandler().playerEntity;
 
         int x = message.x, y = message.y, z = message.z;
 
         TravelSource source = TravelSource.values()[message.source];
 
+        if (!TravelController.instance
+                .validatePacketTravelEvent(toTp, x, y, z, message.powerUse, message.conserveMotion, source)) {
+            Log.LOGGER.warn(
+                    Log.securityMarker,
+                    "Player {} tried to tp without valid prereq.",
+                    ctx.getServerHandler().playerEntity.getGameProfile());
+            return null;
+        }
+
         doServerTeleport(toTp, x, y, z, message.powerUse, message.conserveMotion, source);
 
         return null;