How can I determine the name of the OLE object to create in order to retrieve KBs through WMI?

Question

I am trying to rewrite a C++ program that that retrieves all installed and superseded KBs on a Windows computer in Go.

The C++ program retrieves these KBs by querying for KBs from two different sources:

1. WMI, with the query SELECT * FROM Win32_QuickFixEngineering
2. Update history, with IUpdateSearcher::GetTotalHistoryCount and IUpdateSearcher::QueryHistory

I am seeking help with translating #1 to Go.

I thought the best library I could use for this is go-ole. As an example that uses this library, I looked at the source code for github.com/ceshihao/windowsupdate. I found that this library has the following in order to create an object for querying the update history (source):

unknown, err := oleutil.CreateObject("Microsoft.Update.Session")

I believe this is roughly equivalent to this part of the C++ program I am rewriting (this is from the part that corresponds to item 2 in the list at the beginning of this post):

result = updateSession.CoCreateInstance(CLSID_UpdateSession, nullptr, CLSCTX_INPROC_SERVER);

However, I do not know how to translate this line from a different part of the C++ program (this is from the part that corresponds to item 1 in the list at the beginning of this post):

CComPtr<IWbemLocator> pLoc;

// <...>

// Obtain the initial locator to Windows Management
// on a particular host computer.
hres = pLoc.CoCreateInstance(CLSID_WbemLocator, nullptr, CLSCTX_INPROC_SERVER);

I assume the equivalent Go will be something like this:

unknown, err := oleutil.CreateObject("<mystery string>")

I tried looking at CLSID_WbemLocator's definition using Visual Studio's "Go To Definition" feature, but it is just declared as

EXTERN_C const CLSID CLSID_WbemLocator;

which isn't very helpful.

My question is this: How can I determine what I should use as "<mystery string>" in order to create an object that is equivalent to what the C++ code creates with CLSID_WbemLocator?

Answer 1

Here is the link to IWbemLocator interface documentation.

CLSID_WbemLocator is declared as extern in Wbemcli.h header file for C programs and the CLSID (GUID) constant itself is stored in the library file Wbemuuid.lib. However, for C++ programs it is also defined in Wbemcli.h header file.

From the Wbemcli.h header file:

EXTERN_C const CLSID CLSID_WbemLocator;

#ifdef __cplusplus

class DECLSPEC_UUID("4590f811-1d3a-11d0-891f-00aa004b2e24")
WbemLocator;
#endif

From the Wbemuuid.lib library (file wbemcli_i.obj):

From the registry key HKEY_CLASSES_ROOT\CLSID\{4590F811-1D3A-11D0-891F-00AA004B2E24}:

So the name is simply WBEM Locator.