Feature: Support download payload from http(s) server

server/2015Remote/file_server.h

@@ -0,0 +1,91 @@
+#include <Windows.h>
+#include <string>
+#include <thread>
+#include <filesystem>
+#include <fstream>
+
+#undef min
+#undef max
+#include "httplib.h"
+#ifndef max
+#define max(a,b) (((a) > (b)) ? (a) : (b))
+#endif
+#ifndef min
+#define min(a,b) (((a) < (b)) ? (a) : (b))
+#endif
+
+#pragma comment(lib, "ws2_32.lib")
+
+namespace fs = std::filesystem;
+
+class FileDownloadServer {
+public:
+    FileDownloadServer(int port = 8080) : port_(port) {
+        char exe_path[MAX_PATH];
+        GetModuleFileNameA(NULL, exe_path, MAX_PATH);
+        root_dir_ = fs::path(exe_path).parent_path() / "Payloads";
+        fs::create_directories(root_dir_);
+    }
+
+    bool Start() {
+        server_.Get("/payloads/(.*)", [this](const httplib::Request& req, httplib::Response& res) {
+            std::string filename = req.matches[1];
+
+            if (filename.empty() || filename.find("..") != std::string::npos) {
+                res.status = 403;
+                return;
+            }
+
+            fs::path filepath = root_dir_ / filename;
+
+            if (!fs::exists(filepath) || !fs::is_regular_file(filepath)) {
+                res.status = 404;
+                return;
+            }
+
+            auto filesize = fs::file_size(filepath);
+            std::string path_str = filepath.string();
+
+            res.set_header("Content-Disposition",
+                "attachment; filename=\"" + filename + "\"");
+
+            res.set_content_provider(filesize, "application/octet-stream",
+                [path_str](size_t offset, size_t length, httplib::DataSink& sink) {
+                    std::ifstream file(path_str, std::ios::binary);
+                    if (!file) return false;
+                    file.seekg(offset);
+
+                    char buffer[65536];
+                    size_t remaining = length;
+                    while (remaining > 0 && file) {
+                        size_t to_read = (std::min)(remaining, sizeof(buffer));
+                        file.read(buffer, to_read);
+                        size_t n = (size_t)file.gcount();
+                        if (n == 0) break;
+                        sink.write(buffer, n);
+                        remaining -= n;
+                    }
+                    return true;
+                }
+            );
+            });
+
+        server_thread_ = std::thread([this]() {
+            server_.listen("0.0.0.0", port_);
+            });
+
+        std::this_thread::sleep_for(std::chrono::milliseconds(100));
+        return server_.is_running();
+    }
+
+    void Stop() {
+        server_.stop();
+        if (server_thread_.joinable()) server_thread_.join();
+    }
+
+private:
+    httplib::Server server_;
+    fs::path root_dir_;
+    int port_;
+    std::thread server_thread_;
+};