From 46d21e6c1ba7a7da363589d747c5e6a8793cd7bf Mon Sep 17 00:00:00 2001
From: killerwife <killerwife@gmail.com>
Date: Sun, 10 Sep 2023 22:12:42 +0200
Subject: [PATCH] Fix warden scans terminator logic.

https://github.com/vmangos/core/commit/eeb6d45574e2666ac62dc8fec0d8e9b83584cc65 - all credit goes to this
---
 .../Anticheat/module/Warden/WardenModule.hpp    |  3 +++
 src/game/Anticheat/module/Warden/warden.cpp     |  2 +-
 .../Anticheat/module/Warden/wardenmodule.cpp    | 17 +++++++++++++++++
 3 files changed, 21 insertions(+), 1 deletion(-)

diff --git a/src/game/Anticheat/module/Warden/WardenModule.hpp b/src/game/Anticheat/module/Warden/WardenModule.hpp
index 0ba273554f..921791b41d 100644
--- a/src/game/Anticheat/module/Warden/WardenModule.hpp
+++ b/src/game/Anticheat/module/Warden/WardenModule.hpp
@@ -57,6 +57,9 @@ class WardenModule
     // mapping of scan function to the numerical value of the opcode
     uint8_t opcodes[ScanTypeCount];
 
+    // invalid opcode value that signifies scans are over
+    uint8 scanTerminator;
+
     // pregenerated challenge, responses, and encryption keys for this module
     std::vector<ChallengeResponseEntry> crk;
 };
diff --git a/src/game/Anticheat/module/Warden/warden.cpp b/src/game/Anticheat/module/Warden/warden.cpp
index ca31c6042b..d4036e3a80 100644
--- a/src/game/Anticheat/module/Warden/warden.cpp
+++ b/src/game/Anticheat/module/Warden/warden.cpp
@@ -259,7 +259,7 @@ void Warden::RequestScans(std::vector<std::shared_ptr<const Scan>> &&scans)
     if (_session->GetOS() == CLIENT_OS_WIN)
     {
         // indicates to the client that there are no further requests in this packet
-        buff << _xor;
+        buff << uint8(_module->scanTerminator ^ _xor);
     }
 
     BeginTimeoutClock();
diff --git a/src/game/Anticheat/module/Warden/wardenmodule.cpp b/src/game/Anticheat/module/Warden/wardenmodule.cpp
index f106d3fc29..74003a030d 100644
--- a/src/game/Anticheat/module/Warden/wardenmodule.cpp
+++ b/src/game/Anticheat/module/Warden/wardenmodule.cpp
@@ -81,6 +81,23 @@ WardenModule::WardenModule(std::string const &bin, std::string const &kf, std::s
 
     if (Windows())
     {
+        for (uint8 i = 0; i <= UINT8_MAX; i++)
+        {
+            if (opcodes[0] != i &&
+                opcodes[1] != i &&
+                opcodes[2] != i &&
+                opcodes[3] != i &&
+                opcodes[4] != i &&
+                opcodes[5] != i &&
+                opcodes[6] != i &&
+                opcodes[7] != i &&
+                opcodes[8] != i)
+            {
+                scanTerminator = i;
+                break;
+            }
+        }
+
         if (!memoryRead)
             throw std::runtime_error("Module data does not include memory read information");