From 4c27eb415c5a5370418b66ce998292ae8545c37c Mon Sep 17 00:00:00 2001
From: Ray Koopa <ray@syroot.com>
Date: Sun, 12 Jul 2020 21:27:32 +0200
Subject: [PATCH] Read packets more strictly to prevent crashes from bogus
 data.

---
 src/tool/Syroot.Worms.Worms2.GameServer/Packet.cs | 15 ++++++++++-----
 .../Syroot.Worms.Worms2.GameServer.csproj         |  2 +-
 2 files changed, 11 insertions(+), 6 deletions(-)

diff --git a/src/tool/Syroot.Worms.Worms2.GameServer/Packet.cs b/src/tool/Syroot.Worms.Worms2.GameServer/Packet.cs
index f66f724..b6d7f73 100644
--- a/src/tool/Syroot.Worms.Worms2.GameServer/Packet.cs
+++ b/src/tool/Syroot.Worms.Worms2.GameServer/Packet.cs
@@ -11,6 +11,10 @@ namespace Syroot.Worms.Worms2.GameServer
     /// </summary>
     internal class Packet
     {
+        // ---- CONSTANTS ----------------------------------------------------------------------------------------------
+
+        private const int _maxDataSize = 0x1000;
+
         // ---- CONSTRUCTORS & DESTRUCTOR ------------------------------------------------------------------------------
 
         /// <summary>
@@ -138,8 +142,8 @@ namespace Syroot.Worms.Worms2.GameServer
         internal void Receive(Stream stream)
         {
             int dataLength = 0;
-            Code = (PacketCode)stream.ReadInt32();
-            Flags flags = (Flags)stream.ReadInt32();
+            Code = stream.ReadEnum<PacketCode>(true);
+            Flags flags = stream.ReadEnum<Flags>(true);
             if (flags.HasFlag(Flags.Value0)) Value0 = stream.ReadInt32();
             if (flags.HasFlag(Flags.Value1)) Value1 = stream.ReadInt32();
             if (flags.HasFlag(Flags.Value2)) Value2 = stream.ReadInt32();
@@ -147,7 +151,8 @@ namespace Syroot.Worms.Worms2.GameServer
             if (flags.HasFlag(Flags.Value4)) Value4 = stream.ReadInt32();
             if (flags.HasFlag(Flags.Value10)) Value10 = stream.ReadInt32();
             if (flags.HasFlag(Flags.DataLength)) dataLength = stream.ReadInt32();
-            if (flags.HasFlag(Flags.Data) && dataLength != 0) Data = stream.ReadFixedString(dataLength, Encodings.Windows1252);
+            if (flags.HasFlag(Flags.Data) && dataLength >= 0 && dataLength <= _maxDataSize)
+                Data = stream.ReadFixedString(dataLength, Encodings.Windows1252);
             if (flags.HasFlag(Flags.Error)) Error = stream.ReadInt32();
             if (flags.HasFlag(Flags.Name)) Name = stream.ReadFixedString(20, Encodings.Windows1252);
             if (flags.HasFlag(Flags.Session)) Session = stream.ReadStruct<SessionInfo>();
@@ -159,8 +164,8 @@ namespace Syroot.Worms.Worms2.GameServer
         /// <param name="stream">The <see cref="Stream"/> to write the packet data to.</param>
         internal void Send(Stream stream)
         {
-            stream.WriteInt32((int)Code);
-            stream.WriteInt32((int)GetFlags());
+            stream.WriteEnum(Code);
+            stream.WriteEnum(GetFlags());
             if (Value0.HasValue) stream.WriteInt32(Value0.Value);
             if (Value1.HasValue) stream.WriteInt32(Value1.Value);
             if (Value2.HasValue) stream.WriteInt32(Value2.Value);
diff --git a/src/tool/Syroot.Worms.Worms2.GameServer/Syroot.Worms.Worms2.GameServer.csproj b/src/tool/Syroot.Worms.Worms2.GameServer/Syroot.Worms.Worms2.GameServer.csproj
index 99247e9..ac75ecb 100644
--- a/src/tool/Syroot.Worms.Worms2.GameServer/Syroot.Worms.Worms2.GameServer.csproj
+++ b/src/tool/Syroot.Worms.Worms2.GameServer/Syroot.Worms.Worms2.GameServer.csproj
@@ -7,7 +7,7 @@
     <Authors>Syroot</Authors>
     <Copyright>(c) Syroot, licensed under MIT</Copyright>
     <Description>Worms 2 Game Server</Description>
-    <Version>1.0.0</Version>
+    <Version>1.0.1</Version>
   </PropertyGroup>
 
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