how to get PSID from TOKEN_INFORMATION_CLASS?

Question

I try to use information from this post: https://stackoverflow.com/a/251267/393087

And the code I came up with is:

HANDLE hToken;
OpenProcessToken(GetCurrentProcess(),TOKEN_ADJUST_PRIVILEGES, &hToken);
DWORD dwSize;
TOKEN_INFORMATION_CLASS tokenInformationClass;
GetTokenInformation(hToken, tokenInformationClass, NULL, sizeof(TOKEN_INFORMATION_CLASS), &dwSize);

Ok, so I got TOKEN_INFORMATION_CLASS, but how to get from this to PSID that ConvertSidToStringSid() needs ? There is nowhere PSID word in tic manual page ( http://msdn.microsoft.com/en-us/library/windows/desktop/aa379626(v=vs.85).aspx ).

Answer 1

Well actually this is trivial. Pick whatever token information class you want (my guess is you want TokenUser) and then make sure you pass the matching TOKEN_USER struct to GetTokenInformation, then reach into the TOKEN_USER struct to access TOKEN_USER::User::Sid to get the PSID.

Of course you may also want another token information class, but the principle is the same. Complete sample program (compiled as .cpp file in MSVC):

#ifndef _WIN32_WINNT
#define _WIN32_WINNT 0x0500
#endif                      
#include <stdio.h>
#include <tchar.h>
#include <Windows.h>
#include <Sddl.h> // for ConvertSidToStringSid()

BOOL printTokenUserSid(HANDLE hToken)
{
    PTOKEN_USER ptu = NULL;
    DWORD dwSize = 0;
    if(!GetTokenInformation(hToken, TokenUser, NULL, 0, &dwSize)
        && ERROR_INSUFFICIENT_BUFFER != GetLastError())
    {
        return FALSE;
    }
    if(NULL != (ptu = (PTOKEN_USER)LocalAlloc(LPTR, dwSize)))
    {
        LPTSTR StringSid = NULL;
        if(!GetTokenInformation(hToken, TokenUser, ptu, dwSize, &dwSize))
        {
            LocalFree((HLOCAL)ptu);
            return FALSE;
        }
        if(ConvertSidToStringSid(ptu->User.Sid, &StringSid))
        {
            _tprintf(_T("%s\n"), StringSid);
            LocalFree((HLOCAL)StringSid);
            LocalFree((HLOCAL)ptu);
            return TRUE;
        }
        LocalFree((HLOCAL)ptu);
    }
    return FALSE;
}

int _tmain(int argc, _TCHAR* argv[])
{
    HANDLE hToken = NULL;
    if(OpenThreadToken(GetCurrentThread(), TOKEN_QUERY, FALSE, &hToken)
        || OpenProcessToken(GetCurrentProcess(), TOKEN_QUERY, &hToken))
    {
        if(!printTokenUserSid(hToken))
        {
            _tprintf(_T("Something failed, Win32 error: %d\n"), GetLastError());
        }
        CloseHandle(hToken);
    }
    return 0;
}