From 0bfeaed44a8d669d4d292bc1a2caf75cdf3d50e9 Mon Sep 17 00:00:00 2001
From: nithax <43627008+nithax@users.noreply.github.com>
Date: Fri, 4 Apr 2025 10:01:18 -0400
Subject: [PATCH] XEX2 Loading Fixes (#51)

* Fixes loading .xex import table names when a name is not aligned to 4
  bytes.
* Fixes loading .xex optional headers, adds missing case when the
  header_key & 0xFF == 1
* Fixes loading .xex base address and entry point to be the XEX2
  base/entry to successfully resolve all import thunks.
---
 XenonUtils/xex.cpp | 20 ++++++++++++++++----
 XenonUtils/xex.h   | 10 +++++++---
 2 files changed, 23 insertions(+), 7 deletions(-)

diff --git a/XenonUtils/xex.cpp b/XenonUtils/xex.cpp
index d1972c0..c12d63c 100644
--- a/XenonUtils/xex.cpp
+++ b/XenonUtils/xex.cpp
@@ -201,8 +201,17 @@ Image Xex2LoadImage(const uint8_t* data, size_t dataSize)
     const auto* dosHeader = reinterpret_cast<IMAGE_DOS_HEADER*>(image.data.get());
     const auto* ntHeaders = reinterpret_cast<IMAGE_NT_HEADERS32*>(image.data.get() + dosHeader->e_lfanew);
 
-    image.base = ntHeaders->OptionalHeader.ImageBase;
-    image.entry_point = image.base + ntHeaders->OptionalHeader.AddressOfEntryPoint;
+    image.base = security->loadAddress;
+    const void* xex2BaseAddressPtr = getOptHeaderPtr(data, XEX_HEADER_IMAGE_BASE_ADDRESS);
+    if (xex2BaseAddressPtr != nullptr)
+    {
+        image.base = *reinterpret_cast<const be<uint32_t>*>(xex2BaseAddressPtr);
+    }
+    const void* xex2EntryPointPtr = getOptHeaderPtr(data, XEX_HEADER_ENTRY_POINT);
+    if (xex2EntryPointPtr != nullptr)
+    {
+        image.entry_point = *reinterpret_cast<const be<uint32_t>*>(xex2EntryPointPtr);
+    }
 
     const auto numSections = ntHeaders->FileHeader.NumberOfSections;
     const auto* sections = reinterpret_cast<const IMAGE_SECTION_HEADER*>(ntHeaders + 1);
@@ -227,10 +236,13 @@ Image Xex2LoadImage(const uint8_t* data, size_t dataSize)
         std::vector<std::string_view> stringTable;
         auto* pStrTable = reinterpret_cast<const char*>(imports + 1);
 
+        size_t paddedStringOffset = 0;
         for (size_t i = 0; i < imports->numImports; i++)
         {
-            stringTable.emplace_back(pStrTable);
-            pStrTable += strlen(pStrTable) + 1;
+            stringTable.emplace_back(pStrTable + paddedStringOffset);
+            
+            // pad the offset to the next multiple of 4
+            paddedStringOffset += ((stringTable.back().length() + 1) + 3) & ~3;
         }
 
         auto* library = (Xex2ImportLibrary*)(((char*)imports) + sizeof(Xex2ImportHeader) + imports->sizeOfStringTable);
diff --git a/XenonUtils/xex.h b/XenonUtils/xex.h
index 9ab831e..363efff 100644
--- a/XenonUtils/xex.h
+++ b/XenonUtils/xex.h
@@ -245,13 +245,17 @@ inline const void* getOptHeaderPtr(const uint8_t* moduleBytes, uint32_t headerKe
         const Xex2OptHeader& optHeader = ((const Xex2OptHeader*)(xex2Header + 1))[i];
         if (optHeader.key == headerKey)
         {
-            if ((headerKey & 0xFF) == 0)
+            if((headerKey & 0xFF) == 0)
             {
-                return &optHeader.value;
+                return reinterpret_cast<const uint32_t *>(&optHeader.value);
+            }
+            else if ((headerKey & 0xFF) == 1)
+            {
+                return reinterpret_cast<const void *>(&optHeader.value);
             }
             else
             {
-                return &moduleBytes[optHeader.offset];
+                return reinterpret_cast<const void *>(reinterpret_cast<uintptr_t>(moduleBytes) + optHeader.offset);
             }
         }
     }