From 5cef220e9f2b4d1278a53c07ced5b6ffb319ff2f Mon Sep 17 00:00:00 2001
From: Sajid <sajidur78@gmail.com>
Date: Fri, 13 Sep 2024 16:13:19 +0600
Subject: [PATCH] Implement xex imports

---
 PowerUtils/xex.cpp | 33 +++++++++++++++++++++++++++++-
 PowerUtils/xex.h   | 51 ++++++++++++++++++++++++++++++++++++++++++++--
 2 files changed, 81 insertions(+), 3 deletions(-)

diff --git a/PowerUtils/xex.cpp b/PowerUtils/xex.cpp
index dc658c3..721c1a4 100644
--- a/PowerUtils/xex.cpp
+++ b/PowerUtils/xex.cpp
@@ -1,6 +1,7 @@
 #include "xex.h"
 #include "image.h"
 #include <cassert>
+#include <vector>
 
 Image Xex2LoadImage(const uint8_t* data)
 {
@@ -79,5 +80,35 @@ Image Xex2LoadImage(const uint8_t* data)
             section.Misc.VirtualSize, flags, image.data.get() + section.VirtualAddress);
     }
 
+    auto* imports = Xex2FindOptionalHeader<XEX_IMPORT_HEADER>(header, XEX_HEADER_IMPORT_LIBRARIES);
+    if (imports != nullptr)
+    {
+        std::vector<std::string_view> stringTable;
+        auto* pStrTable = reinterpret_cast<const char*>(imports + 1);
+
+        for (size_t i = 0; i < imports->NumImports; i++)
+        {
+            stringTable.emplace_back(pStrTable);
+            pStrTable += strlen(pStrTable) + 1;
+        }
+
+        auto* library = (XEX_IMPORT_LIBRARY*)(((char*)imports) + sizeof(XEX_IMPORT_HEADER) + imports->SizeOfStringTable);
+        for (size_t i = 0; i < stringTable.size(); i++)
+        {
+            auto* descriptors = (XEX_IMPORT_DESCRIPTOR*)(library + 1);
+            for (size_t im = 0; im < library->NumberOfImports; im++)
+            {
+                auto originalThunk = (XEX_THUNK_DATA*)image.Find(descriptors[im].FirstThunk);
+                auto thunkType = originalThunk->Function >> 24;
+
+                if (thunkType == 1)
+                {
+                    uint32_t thunk[4] = { 0x00000060, 0x00000060, 0x00000060, 0x2000804E };
+                    memcpy(originalThunk, thunk, sizeof(thunk));
+                }
+            }
+        }
+    }
+
     return image;
-}
\ No newline at end of file
+}
diff --git a/PowerUtils/xex.h b/PowerUtils/xex.h
index 0ff0a5e..eb82e54 100644
--- a/PowerUtils/xex.h
+++ b/PowerUtils/xex.h
@@ -7,6 +7,12 @@
 
 #define XEX_ENCRYPTION_NONE 0
 
+enum _XEX_THUNK_TYPES
+{
+    XEX_THUNK_VARIABLE = 0,
+    XEX_THUNK_FUNCTION = 1,
+};
+
 enum _XEX_OPTIONAL_HEADER_TYPES
 {
     XEX_HEADER_RESOURCE_INFO = 0x000002FF,
@@ -54,10 +60,51 @@ typedef struct _XEX_BASIC_FILE_COMPRESSION_INFO
     be<uint32_t> SizeOfPadding;
 } XEX_BASIC_FILE_COMPRESSION_INFO;
 
+typedef struct _XEX_THUNK_DATA {
+    union
+    {
+        struct
+        {
+            WORD Ordinal : 16;
+            WORD Hint : 8;
+            WORD Type : 8;
+        } OriginalData;
+
+        XDWORD Ordinal;
+        XDWORD Function;
+        XDWORD AddressOfData;
+
+        // For easier swapping
+        DWORD Data;
+    };
+} XEX_THUNK_DATA;
+
+typedef struct _XEX_IMPORT_HEADER {
+    XDWORD SizeOfHeader;
+    XDWORD SizeOfStringTable;
+    XDWORD NumImports;
+} XEX_IMPORT_HEADER;
+
+typedef struct _XEX_IMPORT_LIBRARY {
+    XDWORD Size;
+    char NextImportDigest[0x14];
+    XDWORD ID;
+    XDWORD Version;
+    XDWORD MinVersion;
+    XWORD Name;
+    XWORD NumberOfImports;
+} XEX_IMPORT_LIBRARY;
+
+static_assert(sizeof(XEX_IMPORT_LIBRARY) == 0x28);
+
+typedef struct _XEX_IMPORT_DESCRIPTOR {
+    XDWORD FirstThunk; // VA XEX_THUNK_DATA
+} XEX_IMPORT_DESCRIPTOR;
+
 typedef struct _XEX_OPTIONAL_HEADER
 {
-    be<uint32_t> Type;
-    be<uint32_t> Address;
+    XDWORD Type;
+    XDWORD Address;
 } XEX_OPTIONAL_HEADER;
 
 typedef struct _XEX2_SECURITY_INFO