CoInitializeSecurity: Impersonation level for code hosted in a surrogate

From:

Ihab Hanna

Newsgroups:

microsoft.public.vc.language

Date:

Wed, 07 Jan 2009 15:16:09 -0800

Message-ID:

<20091718168i_benjamin_hanna@yahoo.com>

Using C#, I have come across a similar problem and tried the following
---------------------------------------------------
static class Program
{
//**** Program Initialization ****

       [System.Runtime.InteropServices.DllImport("ole32.dll")]
        public static extern int CoInitializeSecurity(IntPtr pVoid, int
            cAuthSvc, IntPtr asAuthSvc, IntPtr pReserved1, xmSam.Defs.RpcAuthnLevel level,
            xmSam.Defs.RpcImpLevel impers, IntPtr pAuthList, xmSam.Defs.EoAuthnCap dwCapabilities, IntPtr
            pReserved3);

        [STAThread]
        static void Main()
        {

            CSecurityManager SecurityManager = new CSecurityManager();

            SecurityManager.Run();

            long nHResult ;

            nHResult = CoInitializeSecurity(IntPtr.Zero,
                     -1,
                     IntPtr.Zero,
                     IntPtr.Zero,
                     RpcAuthnLevel.None,
                     RpcImpLevel.Impersonate,
                     IntPtr.Zero,
                     EoAuthnCap.None,
                     IntPtr.Zero));
#if DEBUG
            if (xmSam.Defs.S_OK != nHResult)
            {

                MessageBox.Show("Security failed to initialize");
            }
            else
            {
                MessageBox.Show("Security has been initialized successfully");
            }
#endif

//******* the rest of my main function in Program.cs **********************

--------------------------------------------------- to overwrite the security level using my .Net application which calls my COM Object (DLL in VC++) but I failed but finally I managed to achieve the impersonation from within the COM itself. In other words,
My C# .Net application has already called CoInitializeSecurity during start up, and since
you can only call this API once during the life of a process, you won't be able to change any settings from your code.
So this is how I did it from my COM using CoSetProxyBlanket().

-----------------------------------------------------
bool MyClass::OverwiteSecurity()
{
    try
    {
        CoInitializeEx(NULL, COINIT_MULTITHREADED);

        CComPtr< IWbemServices > pWbemServices ;
        //IWbemServices*
        CComPtr< IWbemLocator > locator;
        HRESULT hr = CoCreateInstance( CLSID_WbemAdministrativeLocator, NULL,
            CLSCTX_INPROC_SERVER, IID_IWbemLocator,
            reinterpret_cast< void** >( &locator ) );

        if ( FAILED( hr ) )
        {
#ifdef _DEBUG
            MessageBox(NULL, L"Failed to Obtain the initial locator to WMI" , L"MyDllName", MB_OK);
#else
            return false;
#endif
        }

        //CComPtr< IWbemServices > service;
        hr = locator->ConnectServer( L"root\\cimv2", NULL, NULL, NULL,
            WBEM_FLAG_CONNECT_USE_MAX_WAIT, NULL, NULL, &pWbemServices );

        if ( FAILED( hr ) )
        {
#ifdef _DEBUG
            MessageBox(NULL, L"Failed to Connect to WMI through the IWbemLocator" , L"MyDllName", MB_OK);
#else
            return false;
#endif

        }

        // Set proxy security for pWbemServices interface to RPC_C_IMP_LEVEL_IMPERSONATE
        hr = CoSetProxyBlanket(pWbemServices,
          RPC_C_AUTHN_DEFAULT,
          RPC_C_AUTHZ_NONE,
          COLE_DEFAULT_PRINCIPAL,
          RPC_C_AUTHN_LEVEL_DEFAULT,
          RPC_C_IMP_LEVEL_IMPERSONATE,
          NULL,
          EOAC_NONE);
        if (FAILED(hr))
        {
#ifdef _DEBUG
            wchar_t buf[100];
            swprintf( buf, 100, L"%s: %u", L"Count not set proxy blanket1. Error code = ", hr );
            MessageBox(NULL, L"Failed to ConnectServer" , L"MyDllName", MB_OK);
#else
            return false;
#endif
        }

// by now you have overwritten the security level
// and have full control through pWbemServices.
// For example the following piece of code access
// one of WMI database tables to determine whether // a device with a Name like "TECHLOG USB Serial
// Port" is plugged into your one of PC serial
// ports and if so it will retreive the full name of the device which include the COM port # as well.

        CComPtr< IEnumWbemClassObject > enumerator;

        hr = pWbemServices->ExecQuery( L"WQL", L"SELECT * FROM CIM_LogicalDevice where Name like 'TECHLOG USB Serial Port (COM%'",
            WBEM_FLAG_FORWARD_ONLY, NULL, &enumerator );

        if ( SUCCEEDED( hr ) )
        {
            // read the first instance from the enumeration (only one Device)
            CComPtr< IWbemClassObject > Device = NULL;
            ULONG retcnt;
            hr = enumerator->Next( WBEM_INFINITE, 1L, reinterpret_cast<IWbemClassObject**>( &Device ), &retcnt );
            if ( SUCCEEDED( hr ) )
            {
                _variant_t var_val;
                hr = Device->Get( L"Name", 0, &var_val, NULL, NULL );
                if ( SUCCEEDED( hr ) )
                {
                    strDeviceDetails = var_val;
                }
                else
                {
#ifdef _DEBUG
                    MessageBox(NULL, L"Failed to retreive the Name of the Device" , L"MyDllName", MB_OK);
#else
            return false;
#endif
                }
            }
        }
        else
        {
#ifdef _DEBUG
            MessageBox(NULL, L"ID_TECH Card Reder Device not found" , L"MyDllName", MB_OK);
#else
            return false;
#endif
        }

        return true;
    }
    catch(...)
    {
    }

}
-----------------------------------------------------
Hope this answer may help.

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