LsaEnumerateLogonSessions   

Hi,

I need an unique identifier for all loggon sessions. For that I use 
LsaEnumerateLogonSessions and LsaEnumerateLogonSessions.

I've tried microsofts sample code to enumerate logon sessions which can be 
found under: http://msdn.microsoft.com/en-us/library/aa375400(VS.85).aspx

When I start the program on a terminal server, I see all current sessions 
and some previouly logged off. It seems that windows cleans up this 
structure not directly after a logoff.

I need the LUID of the current session. As the LogonSessions struct could 
hold overaged data, a user with the same sessionID could by found more than 
once.

What is the best way, to find out the current LUID? Ignore overaged data and 
just use the newest entry for duplicate entries?
Or is there a better way to get the LUID of the current user?

Thanxs
Dieter

date: Tue, 17 Jun 2008 10:21:05 +0200   author:   Dieter Schmitz

Re: LsaEnumerateLogonSessions   

I've found the solution for my problem.
To determine the current LUID I use the following code:
BOOL GetLUIDOfCurrentUser(void)
{
DWORD dwSize = 0, dwResult = 0;
HANDLE hToken;
PTOKEN_STATISTICS pLUIDInfo;

    // Open a handle to the access token for the calling process.
    if (!OpenProcessToken( GetCurrentProcess(), TOKEN_QUERY, &hToken ))
    {
        printf( "OpenProcessToken Error %u\n", GetLastError() );
        return FALSE;
    }

    // Call GetTokenInformation to get the buffer size.
    if (!GetTokenInformation(hToken, TokenStatistics, NULL, dwSize, 
&dwSize))
    {
        dwResult = GetLastError();
        if( dwResult != ERROR_INSUFFICIENT_BUFFER )
        {
            printf( "GetTokenInformation Error %u\n", dwResult );
            return FALSE;
        }
    }

    // Allocate the buffer.
    pLUIDInfo = (PTOKEN_STATISTICS) GlobalAlloc( GPTR, dwSize );

    // Call GetTokenInformation again to get the token information (LUID).
    if (! GetTokenInformation(hToken, TokenStatistics, pLUIDInfo, dwSize, 
&dwSize ) )
    {
        printf( "GetTokenInformation Error %u\n", GetLastError() );
        return FALSE;
    }

CString sHelp;
sHelp.Format(TEXT("LUID of current user\n\n")
                        TEXT("LowPart: %d\n")
                        TEXT("HighPart: %d\n\n")
                    TEXT("Value: %I64d"), 
pLUIDInfo->AuthenticationId.LowPart, pLUIDInfo->AuthenticationId.HighPart, 
pLUIDInfo->AuthenticationId.LowPart + 
(__int64)((__int64)pLUIDInfo->AuthenticationId.HighPart << 32));
AfxMessageBox(sHelp);

    if ( pLUIDInfo )
   {
        GlobalFree( pLUIDInfo );
   }

    return TRUE;
}

Dieter



"Dieter Schmitz"  schrieb im Newsbeitrag 
news:uuNiXMF0IHA.2312@TK2MSFTNGP05.phx.gbl...
> Hi,
>
> I need an unique identifier for all loggon sessions. For that I use 
> LsaEnumerateLogonSessions and LsaEnumerateLogonSessions.
>
> I've tried microsofts sample code to enumerate logon sessions which can be 
> found under: http://msdn.microsoft.com/en-us/library/aa375400(VS.85).aspx
>
> When I start the program on a terminal server, I see all current sessions 
> and some previouly logged off. It seems that windows cleans up this 
> structure not directly after a logoff.
>
> I need the LUID of the current session. As the LogonSessions struct could 
> hold overaged data, a user with the same sessionID could by found more 
> than once.
>
> What is the best way, to find out the current LUID? Ignore overaged data 
> and just use the newest entry for duplicate entries?
> Or is there a better way to get the LUID of the current user?
>
> Thanxs
> Dieter

date: Tue, 17 Jun 2008 11:25:52 +0200   author:   Dieter Schmitz