Question

I am trying to get a value which i had set on registry key “userpath” of type ‘REG_SZ’. Simplified version of code is below.

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

const static char* SrvKey= "System\\CurrentControlSet\\Services\\LanmanServer\\Parameters";
const static char* sVal = "I am probably \a good boy\0";
const static char* keyName = "userpath";

using namespace std;

int main(int argc, char* argv[]){

    HKEY hkey;
    LONG status;
    DWORD wstatus;
    DWORD dwCtype;
    DWORD dwClen;
    DWORD dwSetStatus;
    status = RegCreateKeyEx(
                HKEY_LOCAL_MACHINE, 
                SrvKey,
                (DWORD) 0,
                NULL,
                REG_OPTION_NON_VOLATILE,
                (KEY_READ | KEY_WRITE),
                NULL,
                &hkey,
                NULL
             );

    if(status != ERROR_SUCCESS){
        printf("Error [%d] on creating key handle\n", status);
        return status;
    }

    //RegFlushKey(hkey);
    dwClen = strlen(sVal);
    dwCtype = REG_SZ;

    dwSetStatus = RegSetValueEx(hkey,
                  keyName,
                  0,
                  dwCtype,
                  (BYTE*)sVal,
                  dwClen);  

    if(dwSetStatus != 0){
                   printf("\nError in setting value in registry. Error [%d]", dwSetStatus);
                   return dwSetStatus;
    }

    RegFlushKey(hkey);

    DWORD dwCheckType = 0;
    DWORD dwCheckLen = 0;
    DWORD dwStatus;
    dwStatus = RegQueryValueEx( hkey,
                               keyName,
                               NULL,
                               &dwCheckType,
                               NULL,
                               &dwCheckLen);
    if(dwStatus != 0){
                printf("\nError in queering registry for length and type. Error [%d]", dwStatus);
                return dwStatus;
    }

    LPBYTE lpbCheckValue = (LPBYTE) malloc(dwCheckLen);

     //dwStatus not check at the moment.
    dwStatus = RegQueryValueEx( hkey,
                                keyName,
                                NULL,
                                &dwCheckType,
                                lpbCheckValue,
                                &dwCheckLen);
    if(dwStatus != 0){
                printf("\nError in queering registry for length and type. Error [%d]", dwStatus);
                return dwStatus;
    }
    printf("queried calue is : [%s]", lpbCheckValue);

    printf("\n\nEndofProgram\n");
    system("PAUSE");
    return 0;
}

I am getting junk value for ‘lpbCheckValue’ after second RegQueryValueE winapi. Please point me what i am doing wrong?

Answer 1

What does sizeof(sVal) give? 4? I’m not sure why you’re using wcslen instead of strlen because sVal is a char*, not wchar_t*.