steamwrap/main.cpp

#include <cstdlib>
#include <iostream>
#include <steam/steam_api.h>
#include <steam/steamclientpublic.h>

#include "httplib.h"

static bool isInitialized = false;

// from https://stackoverflow.com/a/53966346
void btox(char *xp, const char *bb, int n)
{
	const char xx[]= "0123456789ABCDEF";
	while (--n >= 0) xp[n] = xx[(bb[n>>1] >> ((1 - (n&1)) << 2)) & 0xF];
}

int main(int argc, char *argv[]) {
	httplib::Server server;

	server.Post("/init", [] (const httplib::Request &req, httplib::Response &) {
		if (isInitialized) {
			return;
		}

		const bool freeTrial = req.get_param_value("ft") == "1";

		if (freeTrial) {
			putenv("SteamAppId=312060");
			putenv("SteamGameId=312060");
		} else {
			putenv("SteamAppId=39210");
			putenv("SteamGameId=39210");
		}

		if (!SteamAPI_Init()) {
			std::cerr << "Failed to initialize Steam API!" << std::endl;
			return;
		}

		std::cout << "Initialized Steam API..." << std::endl;

		isInitialized = true;
	});
	server.Post("/shutdown", [] (const httplib::Request &, httplib::Response &) {
		if (!isInitialized) {
			return;
		}

		SteamAPI_Shutdown();
	});
	server.Get("/ticket", [] (const httplib::Request &, httplib::Response &res) {
		auto user = SteamAPI_GetHSteamUser();

		const int bufsize = 1024;
		char* buf = new char[bufsize];

		unsigned int length = 0;
		HAuthTicket ret = SteamUser()->GetAuthSessionTicket(buf, bufsize, &length, nullptr);

		char hexstr[length * 2 + 1];
		btox(hexstr, buf, length * 2);
		hexstr[length * 2] = 0;

		res.set_content("{\"ticket\":\"" + std::string(hexstr) + "\",\"time\":" + std::to_string(SteamUtils()->GetServerRealTime()) + "}", "application/json");
	});

    server.listen("0.0.0.0", 50481);

    return 0;
}