#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <time.h>
#include <windows.h>

const char MUTEX[] = "keygen";

void payload()
{
	for (int i = 0; i < 60; ++i)
	{
		printf("\b\b\b\b%is", i++);
		Sleep(1000);
	}
}

void message()
{
	const int N = 35;
	const char alpha[] = "ABCDEFGHIJKLMNOPQRSTUVWXYZ0123456789";
	char key[N];

	srand(time(NULL));

	strcpy(key, "key: ");
	do {
		for (int i = 5; i < N; ++i)
			key[i] = alpha[rand() % strlen(alpha)];
		for (int i = 10; i < N; i += 6)
			key[i] = '-';
		key[N - 1] = '\0';
	} while(MessageBoxA(0, key, MUTEX, MB_ICONINFORMATION|MB_RETRYCANCEL) == IDRETRY);
}

int main(int argc, char *argv[])
{
	HANDLE mutex = OpenMutexA(SYNCHRONIZE, FALSE, MUTEX);

	if (mutex == NULL)
	{
		STARTUPINFO si;
		PROCESS_INFORMATION pi;
		mutex = CreateMutexA(NULL, FALSE, MUTEX);
		CreateProcessA(NULL, argv[0], NULL, NULL, FALSE, 0, NULL, NULL, &si, &pi);
		CloseHandle(pi.hThread);
		CloseHandle(pi.hProcess);
		message();
		ReleaseMutex(mutex);
	}
	else
	{
		payload();
	}

	CloseHandle(mutex);
}