Question

I have a probelm 🙁 i wanna make a program wich gives a random number 🙂 i don’t want use rand() function 🙂 i wanna make one for me then turn it to a function 😉 for educational purpose 🙂
but i have a problem 🙁 see my code 🙂

#include <stdio.h>
#include <iostream>
#include <conio.h>
#include <windows.h>

#define MIN 0
#define MAX 99999

using namespace std;

typedef struct _RANDOM_INFO{
    DWORD random;
    DWORD min;
    DWORD max;
} RANDOM_INFO, * LPRANDOM_INFO;

void Error(LPSTR lpErrorMessage){
    cout << lpErrorMessage << endl;
    exit(EXIT_FAILURE);
}

void GetRandom(LPVOID lpParam){

    DWORD dwListSize = 10000, min = 0, max = 99999;
    LPDWORD lpRandom = (LPDWORD)lpParam;
    LPSTR lpFileSelf, lpKernel, lpNtdll;    
    HMODULE hFileSelf = NULL, hKernel = NULL, hNtdll = NULL;

    hFileSelf = (HMODULE) GetModuleHandle(NULL);
    hKernel = (HMODULE) GetModuleHandle("kernel.dll");
    hNtdll = (HMODULE) GetModuleHandle("ntdll.dll");

    lpFileSelf = (LPSTR) hFileSelf;
    lpKernel = (LPSTR) hKernel;
    lpNtdll = (LPSTR) hNtdll;

    while(1){
        DWORD i;
        for(i = 0; i <= dwListSize; i++){
            *lpRandom = (DWORD)lpFileSelf[i];   
        }
        i = 0;
    }

    return;
}

int main(int argc, char **argv)
{
    DWORD random = 0;

    DWORD getRandomThreadId = 0;

    HANDLE hGetRandomThread = CreateThread(NULL, 0, (LPTHREAD_START_ROUTINE)GetRandom, &random, 0, &getRandomThreadId);
    if(hGetRandomThread == INVALID_HANDLE_VALUE)
        Error("Cannot make a random list.");

    getch();

    cout << random << endl;
    Sleep(1500);

    return 0;
}

The variable should get a value when and print it but i always i get 0 and a windows error can someone tell me why??? and another problem when i try to use the variable hKernel in the GetRandom function i get an error too 🙁 but it works fine whith hFileSelf and hNtdll !!!! is kernel protected from reading???

Note : this is not a random number generation 🙂 its just a way to get a number from the memory when the user click on the enter on his keyboard :), and its not always the same time for all users so its not always the same pointer in memory 🙂 i hope u understand what i want do 🙂 sorry for my bad englush 🙂 just help me to fix the problem 🙂

Thank u 🙂

Answer 1

Your GetRandom() function does not have the correct signature for a CreateThread() callback procedure. Try this instead:

#include <stdio.h>
#include <iostream>
#include <conio.h>
#include <windows.h>

#define MIN 0
#define MAX 99999

using namespace std;

typedef struct _RANDOM_INFO
{
    DWORD random;
    DWORD min;
    DWORD max;
} RANDOM_INFO, * LPRANDOM_INFO;

void Error(LPSTR lpErrorMessage)
{
    cout << lpErrorMessage << endl;
    exit(EXIT_FAILURE);
}

HMODULE hFileSelf = (HMODULE) GetModuleHandle(NULL);

DWORD WINAPI GetRandomThreadProc(LPVOID lpParam)
{
    LPDWORD lpRandom = (LPDWORD) lpParam;

    DWORD dwListSize = 10000, min = 0, max = 99999;
    LPBYTE lpFileSelf = (LPBYTE) hFileSelf;

    while (1)
    {
        for (DWORD i = 0; i <= dwListSize; ++i)
        {
            *lpRandom = (DWORD) lpFileSelf[i];   
        }

        Sleep(0);
    }

    return 0;
}

int main(int argc, char **argv)
{
    DWORD dwRandom = 0;
    DWORD dwRandomThreadId = 0;

    HANDLE hGetRandomThread = CreateThread(NULL, 0, &GetRandomThreadProc, &dwRandom, 0, &dwRandomThreadId);
    if (hGetRandomThread == INVALID_HANDLE_VALUE)
        Error("Cannot make a random list.");

    do
    {
        getch();
        cout << dwRandom << endl;
    }
    while (WaitForSingleObject(hGetRandomThread, 0) == WAIT_TIMEOUT);

    CloseHandle(hGetRandomThread);

    return 0;
}