initial

defendnot-loader/core/inject.cpp

@@ -0,0 +1,58 @@
+#include "core/core.hpp"
+
+#include "shared/defer.hpp"
+#include <print>
+#include <stdexcept>
+
+#include <Windows.h>
+
+namespace loader {
+    [[nodiscard]] HANDLE inject(std::string_view dll_path, std::string_view proc_name) {
+        STARTUPINFOA si = {
+            .cb = sizeof(si),
+        };
+        PROCESS_INFORMATION pi = {
+            0,
+        };
+        SECURITY_ATTRIBUTES sa = {
+            .nLength = sizeof(sa),
+            .bInheritHandle = TRUE,
+        };
+
+        std::println("** booting {}", proc_name);
+        if (!CreateProcessA(nullptr, const_cast<char*>(proc_name.data()), &sa, &sa, FALSE, CREATE_SUSPENDED, nullptr, nullptr, &si, &pi)) {
+            throw std::runtime_error(std::format("unable to create process: {}", GetLastError()));
+        }
+
+        defer->void {
+            CloseHandle(pi.hThread);
+            /// Not closing hProcess because we return it
+        };
+
+        LPVOID mem = VirtualAllocEx(pi.hProcess, nullptr, dll_path.size() + 1, MEM_COMMIT | MEM_RESERVE, PAGE_READWRITE);
+        if (mem == nullptr) {
+            throw std::runtime_error(std::format("unable to allocate memory: {}", GetLastError()));
+        }
+
+        defer->void {
+            VirtualFreeEx(pi.hProcess, mem, 0, MEM_RELEASE);
+        };
+
+        if (!WriteProcessMemory(pi.hProcess, mem, dll_path.data(), dll_path.size() + 1, nullptr)) {
+            throw std::runtime_error(std::format("unable to write memory: {}", GetLastError()));
+        }
+
+        HANDLE thread = CreateRemoteThread(pi.hProcess, nullptr, 0, reinterpret_cast<LPTHREAD_START_ROUTINE>(LoadLibraryA), mem, 0, nullptr);
+        if (thread == NULL) {
+            throw std::runtime_error(std::format("unable to create thread: {}", GetLastError()));
+        }
+
+        defer->void {
+            CloseHandle(thread);
+        };
+
+        /// Wait for DllMain to complete
+        WaitForSingleObject(thread, INFINITE);
+        return pi.hProcess;
+    }
+} // namespace loader