WIP Patch

patcher/patcher.cpp

@@ -139,5 +139,58 @@ int main(int argc, char *argv[]) {
   spdlog::info(".text section RVA: 0x{:x}, size: 0x{:x}", textSectionRVA, textSectionSize);
   spdlog::info(".text section VA: 0x{:x} - 0x{:x}", textSectionVA, textSectionEndVA);
 
+  // Find available space at the end of .text section (look for null bytes)
+  auto textSectionData = textSection->get_data();
+  uint32_t originalTextSize = textSection->get_data_size();
+  
+  // Search backwards from the end to find contiguous null bytes
+  uint32_t availableSpace = 0;
+  for (int32_t i = originalTextSize - 1; i >= 0; i--) {
+    if (reinterpret_cast<const uint8_t*>(textSectionData)[i] == 0x00) {
+      availableSpace++;
+    } else {
+      break; // Found non-null byte, stop counting
+    }
+  }
+  
+  spdlog::info("Found {} bytes of available space (null bytes) at end of .text section", availableSpace);
+  
+  if (availableSpace < mainSize) {
+    spdlog::error("Not enough space in .text section! Need {} bytes, found {} bytes", 
+                  mainSize, availableSpace);
+    return 1;
+  }
+  
+  // Calculate injection offset (place code at start of null space)
+  uint32_t injectionOffset = originalTextSize - availableSpace;
+  uint64_t injectionVA = textSectionVA + injectionOffset;
+  
+  spdlog::info("Injecting {} bytes at .text section offset 0x{:x} (VA: 0x{:x})", 
+               mainSize, injectionOffset, injectionVA);
+
+  // Copy the main function code into the available space
+  const uint8_t* mainCode = reinterpret_cast<const uint8_t*>(mainCodeData) + mainOffset;
+  
+  // Create a copy of the section data to modify
+  std::vector<uint8_t> newTextData(reinterpret_cast<const uint8_t*>(textSectionData), 
+                                   reinterpret_cast<const uint8_t*>(textSectionData) + originalTextSize);
+  
+  // Copy our code into the null space
+  std::memcpy(newTextData.data() + injectionOffset, mainCode, mainSize);
+  
+  // Update the .text section with modified data (same size)
+  textSection->set_data(reinterpret_cast<const char*>(newTextData.data()), newTextData.size());
+  
+  spdlog::info("Injected code into existing .text section space (size unchanged: 0x{:x})", originalTextSize);
+  
+  // Save the modified PE file to output path
+  spdlog::info("Saving patched PE file to: {}", outputFile);
+  if (!peReader.save(outputFile)) {
+    spdlog::error("Failed to save patched PE file to: {}", outputFile);
+    return 1;
+  }
+  
+  spdlog::info("Successfully patched PE file! Main function injected at VA: 0x{:x}", injectionVA);
+
   return 0;
 }