Paper/CraftBukkit-Patches/0038-Prevent-handshake-spam-from-invalid-names.patch

From 7371e8acd34c5e462e59f990240dc52e44aeb962 Mon Sep 17 00:00:00 2001
From: Benjamin James Harrison-Sims <tehrainbowguy@gmail.com>
Date: Sun, 14 Apr 2013 21:19:57 +0500
Subject: [PATCH] Prevent handshake spam from invalid names.


diff --git a/src/main/java/net/minecraft/server/Packet2Handshake.java b/src/main/java/net/minecraft/server/Packet2Handshake.java
index 343af93..aa6609b 100644
--- a/src/main/java/net/minecraft/server/Packet2Handshake.java
+++ b/src/main/java/net/minecraft/server/Packet2Handshake.java
@@ -1,5 +1,7 @@
 package net.minecraft.server;
 
+import org.bukkit.craftbukkit.Spigot;
+
 import java.io.DataInputStream;
 import java.io.DataOutputStream;
 
@@ -19,6 +21,7 @@ public class Packet2Handshake extends Packet {
         this.b = a(datainputstream, 16);
         this.c = a(datainputstream, 255);
         this.d = datainputstream.readInt();
+        if(!Spigot.validName.matcher(this.b).matches()) throw new IOException("Invalid name!"); // Spigot
     }
 
     public void a(DataOutputStream dataoutputstream) throws IOException { // CraftBukkit - throws IOException
diff --git a/src/main/java/org/bukkit/craftbukkit/Spigot.java b/src/main/java/org/bukkit/craftbukkit/Spigot.java
index 9ac137a..8772350 100644
--- a/src/main/java/org/bukkit/craftbukkit/Spigot.java
+++ b/src/main/java/org/bukkit/craftbukkit/Spigot.java
@@ -6,6 +6,7 @@ import java.net.InetAddress;
 import java.util.ArrayList;
 import java.util.List;
 import java.util.logging.Level;
+import java.util.regex.Pattern;
 import net.minecraft.server.AxisAlignedBB;
 import net.minecraft.server.Chunk;
 import net.minecraft.server.Entity;
@@ -56,6 +57,7 @@ public class Spigot {
     private static Metrics metrics;
     public static List<String> bungeeIPs;
     public static int textureResolution = 16;
+    public static final Pattern validName = Pattern.compile("^[a-zA-Z0-9_-]{2,16}$");
 
     public static void initialize(CraftServer server, SimpleCommandMap commandMap, YamlConfiguration configuration) {
         commandMap.register("bukkit", new org.bukkit.craftbukkit.command.TicksPerSecondCommand("tps"));
@@ -380,7 +382,9 @@ public class Spigot {
     }
 
     /**
-     * Gets the range an entity should be 'tracked' by players and visible in the client.
+     * Gets the range an entity should be 'tracked' by players and visible in
+     * the client.
+     *
      * @param entity
      * @param defaultRange Default range defined by Mojang
      * @return
-- 
1.8.1.2