checking file premission c/cpp windows

Question

i am working on a visual studio project in windows. i want to check what privileges a file has (special write), for now i am using :

hFile = CreateFile(wtext,           // name of the write
            GENERIC_WRITE,          // open for writing
            0,                      // do not share
            NULL,                   // default security
            OPEN_EXISTING,          // open only if exists
            FILE_ATTRIBUTE_NORMAL,  // normal file
            NULL);                  // no attr. template

i dont want to use CreateFile because for some files i need to run my prog as Administrator to get the results.

how do i check file access details without using CreateFile?

Your code doesn't check privileges. It opens a file. What are you actually trying to do? — David Heffernan, Mar 11 '15 at 12:50
i know, i want to check write privileges on a file and because i dont know how to do it , i use the CreateFile function with the generic_write and open_existing and after use if (hFile == INVALID_HANDLE_VALUE) to manipulate and see if i had write privileges — Omega Doe, Mar 11 '15 at 12:56
Define what you mean by "check write privileges". Do you mean whether or not the current process user token has sufficient rights to perform that action? — David Heffernan, Mar 11 '15 at 13:01
If the user session has write privileges on a file. for example, some dll in c:\program files has RW access to SERVICE\TrustedInstaller while BUILTIN\Users has only R access — Omega Doe, Mar 11 '15 at 13:03

score 0 · Answer 1 · answered Mar 11 '15 at 12:18

Why not checking if the user has Administrator rights ?

BOOL CYourClass::IsElevated(void)
{
    BOOL ret = FALSE;
    HANDLE hToken = nullptr;
    if (OpenProcessToken(GetCurrentProcess(), TOKEN_QUERY, &hToken))
    {
        TOKEN_ELEVATION Elevation = {0};
        DWORD dwSize = sizeof(TOKEN_ELEVATION);
        if (GetTokenInformation(hToken, TokenElevation, &Elevation, sizeof(Elevation), &dwSize))
        {
            ret = Elevation.TokenIsElevated;
        }
    }
    if (hToken)
        CloseHandle(hToken);
    return ret;
}

i want to active it also if the user logged on has no admin rights — Omega Doe, Mar 11 '15 at 12:26

checking file premission c/cpp windows

1 Answers1