Using LUA/UAP in custom applicatons

Using LUA/UAP in custom applicatons

• VB 2005 User

  If you're not using a real proxy/stub DLL, then you need to merge the proxy/stub code into your type library. The easiest way to do this is to make create a new ATL project in Visual Studio, and make sure you check the "Allow merging of proxy/stub code" checkbox in the ATL Project Wizard.

  After you do this, you also need to define _MERGE_PROXYSTUB in the project settings, the wizard doesn't do this for you for some reason.

  Since you're creating an instance of your COM object in a different process, Windows needs the proxy/stub code to marshal parameters across process boundaries.

  If you merge the proxy/stub code into your type library, then simply registering your DLL with regsvr32 should create all the correct registry entries. If you create a separate proxy/stub DLL, you will need to register that as well.

  
  

• Martin Flores

  Please, can anybody from MS help us with CoCreateInstanceAdmin() or is it CoCreateInstanceAsAdmin() It is mentioned here http://msdn.microsoft.com/windowsvista/default.aspx pull=/library/en-us/dnlong/html/AccProtVista.asp in both forms, but SDK doesn't define anything like this.
  
  

• chuck620

  I agree, I wish there were some code samples for this. I'm trying to use an elevated out-of-process COM object to perform operations that require administrative priviliges, but I've been unable to get this to work. The Best practices and guidelines article you refer to talks about a new API called CoCreateInstanceAsAdmin(). I've since been told that there isn't going to be a new API for this, instead the moniker syntax for CoGetObject() will be enhanced so you can implement this routine yourself:

  inline HRESULT
  CoCreateInstanceAsAdmin(
  __in_opt HWND hwndParent,
  __in REFCLSID rclsid,
  __in REFIID riid,
  __deref_out PVOID *ppv
  )
  {
  HRESULT hr;
  BIND_OPTS3 bo;
  WCHAR wszCLSID[50];
  WCHAR wszMonikerName[300];

  *ppv = NULL;

  if (0 == StringFromGUID2(rclsid, wszCLSID, RTL_NUMBER_OF(wszCLSID)))
  {
  return E_OUTOFMEMORY;
  }

  hr = StringCchPrintf(wszMonikerName,
  RTL_NUMBER_OF(wszMonikerName),
  L"Elevation:Administrator!new:%s",
  wszCLSID);
  if (FAILED(hr))
  {
  return hr;
  }
  
  RtlZeroMemory(&bo, sizeof(bo));
  
  bo.cbStruct = sizeof(bo);
  bo.hwnd = hwndParent;
  bo.dwClassContext = CLSCTX_LOCAL_SERVER;
  return CoGetObject(wszMonikerName, &bo, riid, ppv);
  }

  I still can't get this to work, CoGetObject() fails with CO_E_MISSING_DISPLAYNAME (0x80080015L), a new error in WinError.h in the Vista SDK that's described as "The activation requires a display name to be present under the CLSID key." Even with a DisplayName string under my CLSID key, I still get this error with the 5270 build of VIsta.

  Anyway, maybe this information will be helpful to you.

  
  

• velt

  
  Guess it pays to read the blogs frequently :)

  Add the LUA/UAP (now called UAC, user account control) team's blog to your bookmarks! Got a link from their old blog that points to excellent papers on this topic.

  Getting started with UAP
  http://www.microsoft.com/technet/windowsvista/evaluate/feat/uaprot.mspx

  Gaming with Least-priviliged user accounts
  http://msdn.microsoft.com/library/default.asp url=/library/en-us/directx9_c/Gaming_with_Least_Privileged_User_Accounts.asp

  Best practices and guidelines
  http://msdn.microsoft.com/windowsvista/default.aspx pull=/library/en-us/dnlong/html/AccProtVista.asp

  The papers (specially the getting started and best practices) are really really helpful, but are painfully long and hard to understand at first pass. I did see references to functions and IDs that developers can use in their apps and achive what I was asking in the above message. This is really great, and I hope they extend the API to work from both unmanaged C++ apps, as well as applications that use the .net framework (including WinFx).

  I don't think the December CTP SDK has any samples on this API set, but would be intersting to see a simple demo app that can mimic say the date/time settings dialog (UAP dialog pops up when the settings button is clicked, etc).

   

   

   

  
  

• Damodarnet

  Hi all,

  I have tried to implement CoCreateInstanceAsAdmin too.

  I have already implement the Elevation in my COM Dll  foo.rgs as follow:

     Elevation
     {
        val Enabled = d 1
     }
     val LocalizedString = s 'Elevation AppReg.dll'

  However I still got  (0x80080017L) error when I call CoGetObject()

  Does anyone know what error means

  (P.S. I use the Vista beta 2 build 5472.)

  
  

• avidan

  Cool! I was getting the same Invalid Data error code and after fixed the LocalizedString, bingo! It works. There sure need better documentation on this. Otherwise, how can one figure it out
  
  

• lavasurfer

  <bump>
  
  Can you go over the steps you had to take to get elevation to work on your COM DLL I'm a little ticked that there still isn't solid, easily found documentation on this when MS expects developers to get their apps Vista/UAC compliant. I'm glad you were able to get it to work.
  
  I've tried the steps in the elevation moniker topic, using MSDN's sample CoCreateInstanceAsAdmin but I keep getting a COM variation of ERROR_INVALID_DATA. What does this mean I can do a regular CoCreateInstance just fine, with both CLSCTX_INPROC_SERVER and CLSCTX_LOCAL_SERVER. I'm not using a real proxy/stub DLL, I'm just using the DllSurrogate registry entry and generic marshalling. Is that an issue I set the registry settings as indicated on MSDN, for Elevation\Enabled and LocalizedString.
  
  I've tried using their version of CoCreateInstanceAsAdmin, which uses CoGetObject (relatively high-level function), and I also tried making a longer brute-force version that calls all the APIs that CoGetObject calls. Both versions choke with ERROR_INVALID_DATA, from CoGetObject in the first version and BindToObject in the 2nd.
  
  Do you think you can post some sample code and registry settings It would be much appreciated.
  
  

• Tony Castagno

  Thanks. The specific web page is:

  http://msdn.microsoft.com/library/default.asp url=/library/en-us/com/html/1595ebb8-65af-4609-b3e7-a21209e64391.asp

  Now that I know about the LocalizedString and Elevation\Enabled keys, I've almost got this working. Vista prompts me with the elevation UI using the display name I specified, but then the CoGetObject() call fails with REGDB_E_CLASSNOTREG. Obviously, it knows the class is implemented by my DLL, since it's showing me my display name. I can successfully create an instance of my COM object using CoCreateInstance(). I'm not sure what's wrong.

  
  

• binks120

  you can find it in Feb CTP PSDK
  

• RonRandall

  The documentation is incorrect, in that LocalizedString is not merely a displayname. Make sure you use a resource DLL, and code in the value as something like this:
  
  @path\to\your\dll,-1000
  
  Where 1000 is the string resource ID for the localized string to be displayed in the elevation dialog.
  
  

• newbied

  Hi,

  I get this working as PA only (consent prompt). As limited User the Elevation UI is displayed, logon succeeds, however my method returns "Access denied". What am I doing wrong

  Regards,

  AGDD

  
  

• Andrew Tregonning

  I've got it working now, the problem was that my COM DLL wasn't configured to run out-of-process. Specifically, I needed to add an empty DllSurrogate key under my AppID in the registry, and register the proxy/stub DLL. With those changes, I was able to successfully instantiate an out-of-process COM object with elevated priviliges.
  

• Philip Painter

  Can you go over the steps you had to take to get elevation to work on your COM DLL I'm a little ticked that there still isn't solid, easily found documentation on this when MS expects developers to get their apps Vista/UAC compliant. I'm glad you were able to get it to work.
  
  I've tried the steps in the elevation moniker topic, using MSDN's sample CoCreateInstanceAsAdmin but I keep getting a COM variation of ERROR_INVALID_DATA. What does this mean I can do a regular CoCreateInstance just fine, with both CLSCTX_INPROC_SERVER and CLSCTX_LOCAL_SERVER. I'm not using a real proxy/stub DLL, I'm just using the DllSurrogate registry entry and generic marshalling. Is that an issue I set the registry settings as indicated on MSDN, for Elevation\Enabled and LocalizedString.
  
  I've tried using their version of CoCreateInstanceAsAdmin, which uses CoGetObject (relatively high-level function), and I also tried making a longer brute-force version that calls all the APIs that CoGetObject calls. Both versions choke with ERROR_INVALID_DATA, from CoGetObject in the first version and BindToObject in the 2nd.
  
  Do you think you can post some sample code and registry settings It would be much appreciated.
  
  

• Talonius

  Did you set the key

  HKEY_LOCAL_MACHINE\Software\Classes\CLSID\

  {CLSID}\LocalizedString = <displayname>

  If this entry is missing, the activation returns the error CO_E_MISSING_DISPLAYNAME.

  
  
• Using LUA/UAP in custom applicatons