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Exploring Delphi XE3 – WinApi Additions – Winapi.Wbem

9 Comments

Delphi XE3 introduces a lot of new WinApi headers translations, between them is the Winapi.Wbem unit which is the Delphi (object pascal) translation for the wbemidl.h file which contains the WMI Component Object Model (COM) interface definitions. This means that from now you can access the WMI in a fastest way and directly using COM avoiding the use of the Microsoft WMIScripting Library and third party libraries.

Try this sample Delphi XE3 console application which access the Win32_Process WMI Class using the Winapi.Wbem unit.

{$APPTYPE CONSOLE}

{$R *.res}

uses
  Winapi.Windows,
  System.SysUtils,
  Winapi.ActiveX,
  Winapi.Wbem;

const
  //Impersonation Level Constants
  //http://msdn.microsoft.com/en-us/library/ms693790%28v=vs.85%29.aspx
  RPC_C_AUTHN_LEVEL_DEFAULT   = 0;
  RPC_C_IMP_LEVEL_ANONYMOUS   = 1;
  RPC_C_IMP_LEVEL_IDENTIFY    = 2;
  RPC_C_IMP_LEVEL_IMPERSONATE = 3;
  RPC_C_IMP_LEVEL_DELEGATE    = 4;

  //Authentication Service Constants
  //http://msdn.microsoft.com/en-us/library/ms692656%28v=vs.85%29.aspx
  RPC_C_AUTHN_WINNT      = 10;
  RPC_C_AUTHN_LEVEL_CALL = 3;
  RPC_C_AUTHN_DEFAULT    = Longint($FFFFFFFF);
  EOAC_NONE              = 0;

  //Authorization Constants
  //http://msdn.microsoft.com/en-us/library/ms690276%28v=vs.85%29.aspx
  RPC_C_AUTHZ_NONE       = 0;
  RPC_C_AUTHZ_NAME       = 1;
  RPC_C_AUTHZ_DCE        = 2;
  RPC_C_AUTHZ_DEFAULT    = Longint($FFFFFFFF);

  //Authentication-Level Constants
  //http://msdn.microsoft.com/en-us/library/aa373553%28v=vs.85%29.aspx
  RPC_C_AUTHN_LEVEL_PKT_PRIVACY   = 6;
  SEC_WINNT_AUTH_IDENTITY_UNICODE = 2;

 //COAUTHIDENTITY Structure
 //http://msdn.microsoft.com/en-us/library/ms693358%28v=vs.85%29.aspx
 type
    PCOAUTHIDENTITY    = ^TCOAUTHIDENTITY;
    _COAUTHIDENTITY    = Record
                          User           : PChar;
                          UserLength     : ULONG;
                          Domain         : PChar;
                          DomainLength   : ULONG;
                          Password       : PChar;
                          PassWordLength : ULONG;
                          Flags          : ULONG;
                          End;

   COAUTHIDENTITY      = _COAUTHIDENTITY;
   TCOAUTHIDENTITY     = _COAUTHIDENTITY;



function GetExtendedErrorInfo(hresErr: HRESULT):Boolean;
var
 pStatus    : IWbemStatusCodeText;
 hres       : HRESULT;
 MessageText: WideString;
begin
  Result:=False;
    hres := CoCreateInstance(CLSID_WbemStatusCodeText, nil, CLSCTX_INPROC_SERVER, IID_IWbemStatusCodeText, pStatus);
    if (hres = S_OK) then
    begin
     hres := pStatus.GetErrorCodeText(hresErr, 0, 0, MessageText);
     if(hres <> S_OK) then
       MessageText := 'Get last error failed';

     Result:=(hres = S_OK);
     if Result then
      Writeln(Format( 'ErrorCode %x Description %s',[hresErr,MessageText]));
    end;
end;


procedure  TestWbem;
const
  WbemUser            ='';
  WbemPassword        ='';
  WbemComputer        ='localhost';
  WbemLocale          ='';
  WbemAuthority       ='kERBEROS:'+WbemComputer;
var
  LWbemLocator         : IWbemLocator;
  LWbemServices        : IWbemServices;
  LUnsecuredApartment  : IUnsecuredApartment;
  ppEnum               : IEnumWbemClassObject;
  apObjects            : IWbemClassObject;
  puReturned           : ULONG;
  pVal                 : Variant;
  pType                : PCIMTYPE;
  plFlavor             : PInteger;
  OpResult             : HRESULT;
  LocalConnection      : Boolean;
  AuthInfo             : TCOAUTHIDENTITY;
begin
  ZeroMemory(@AuthInfo, 0);
  with AuthInfo do
  begin
    User           := PChar(WbemUser);
    UserLength     := Length(WbemUser);
    Domain         := '';
    DomainLength   := 0;
    Password       := PChar(WbemPassword);
    PasswordLength := Length(WbemPassword);
    Flags          := SEC_WINNT_AUTH_IDENTITY_UNICODE;
  end;

  LocalConnection:=WbemComputer.IsEmpty or (WbemComputer.CompareTo('localhost')=0);
  if LocalConnection then
   if Failed(CoInitializeSecurity(nil, -1, nil, nil, RPC_C_AUTHN_LEVEL_DEFAULT, RPC_C_IMP_LEVEL_IMPERSONATE, nil, EOAC_NONE, nil)) then Exit
   else
  else
   if Failed(CoInitializeSecurity(nil, -1, nil, nil, RPC_C_AUTHN_LEVEL_DEFAULT, RPC_C_IMP_LEVEL_IDENTIFY, nil, EOAC_NONE, nil)) then Exit;


  OpResult:=CoCreateInstance(CLSID_WbemLocator, nil, CLSCTX_INPROC_SERVER, IID_IWbemLocator, LWbemLocator);
  if Succeeded(OpResult) then
  begin
    try
      Writeln('Connecting to the WMI Service');
      if LocalConnection then
        OpResult:=LWbemLocator.ConnectServer(Format('\\%s\root\CIMV2',[WbemComputer]), WbemUser, WbemPassword, WbemLocale,  WBEM_FLAG_CONNECT_USE_MAX_WAIT, '', nil, LWbemServices)
      else
        OpResult:=LWbemLocator.ConnectServer(Format('\\%s\root\CIMV2',[WbemComputer]), WbemUser, WbemPassword, WbemLocale,  WBEM_FLAG_CONNECT_USE_MAX_WAIT, '', nil, LWbemServices);


      if Succeeded(OpResult) then
      begin
        Writeln('Connected');
        try
          // Set security levels on a WMI connection
          if LocalConnection then
            if Failed(CoSetProxyBlanket(LWbemServices, RPC_C_AUTHN_WINNT, RPC_C_AUTHZ_NONE, nil, RPC_C_AUTHN_LEVEL_CALL, RPC_C_IMP_LEVEL_IMPERSONATE, nil, EOAC_NONE)) then Exit
             else
          else
            if Failed(CoSetProxyBlanket(LWbemServices, RPC_C_AUTHN_DEFAULT, RPC_C_AUTHZ_DEFAULT, PWideChar(Format('\\%s',[WbemComputer])), RPC_C_AUTHN_LEVEL_PKT_PRIVACY, RPC_C_IMP_LEVEL_IMPERSONATE, @AuthInfo, EOAC_NONE)) then Exit;

          if Succeeded(CoCreateInstance(CLSID_UnsecuredApartment, nil, CLSCTX_LOCAL_SERVER, IID_IUnsecuredApartment, LUnsecuredApartment)) then
          try
            Writeln('Running Wmi Query');
            OpResult := LWbemServices.ExecQuery('WQL', 'SELECT Name, ProcessId FROM Win32_Process', WBEM_FLAG_FORWARD_ONLY, nil, ppEnum);
            if Succeeded(OpResult) then
            begin
               // Set security for the enumerator proxy
               if not LocalConnection then
                if Failed(CoSetProxyBlanket(ppEnum, RPC_C_AUTHN_DEFAULT, RPC_C_AUTHZ_DEFAULT, PWideChar(Format('\\%s',[WbemComputer])), RPC_C_AUTHN_LEVEL_PKT_PRIVACY, RPC_C_IMP_LEVEL_IMPERSONATE, @AuthInfo, EOAC_NONE)) then Exit;

               while (ppEnum.Next(Integer(WBEM_INFINITE), 1, apObjects, puReturned)=0) do
               begin
                 pType:=nil;
                 plFlavor:=nil;

                 apObjects.Get('Name', 0, pVal, pType, plFlavor);// String
                 Writeln(Format('Name         %s',[String(pVal)]));//String
                 VarClear(pVal);

                 apObjects.Get('ProcessId', 0, pVal, pType, plFlavor);// Uint32
                 Writeln(Format('ProcessId    %d',[Integer(pVal)]));//Uint32
                 VarClear(pVal);
               end;
            end
            else
            if not GetExtendedErrorInfo(OpResult) then
            Writeln(Format('Error executing WQL sentence %x',[OpResult]));
          finally
            LUnsecuredApartment := nil;
          end;
        finally
          LWbemServices := nil;
        end;
      end
      else
        if not GetExtendedErrorInfo(OpResult) then
        Writeln(Format('Error Connecting to the Server %x',[OpResult]));
    finally
      LWbemLocator := nil;
    end;
  end
  else
   if not GetExtendedErrorInfo(OpResult) then
     Writeln(Format('Failed to create IWbemLocator object %x',[OpResult]));

end;


begin
 try
    if Succeeded(CoInitializeEx(nil, COINIT_MULTITHREADED)) then
    try
      TestWbem;
    finally
      CoUninitialize;
    end;
 except
    on E:Exception do
        Writeln(E.Classname, ':', E.Message);
 end;
 Writeln('Press Enter to exit');
 Readln;
end.

Author: Rodrigo

Just another Delphi guy.

9 thoughts on “Exploring Delphi XE3 – WinApi Additions – Winapi.Wbem

  1. Very nice indeed.

    Are there any other particularly interesting new header translations?

    • This is the full list of the new WinApi headers included in Delphi XE3

      Function Discovery API – functiondiscoverycategories.h – Winapi.Functiondiscovery
      Location API – locationapi.h – Winapi.Locationapi
      Shell Functions functions from the Userenv.dll library – userenv.h – Winapi.UserEnv
      Sensor API – sensorsapi.h – Winapi.Sensorsapi
      Sensor API – Sensors.h – Winapi.Sensors
      Windows Portable Devices (WPD) – portabledevicetypes.h – Winapi.Portabledevicetypes
      PenInputPanel interfaces – peninputpanel.h – Winapi.PenInputPanel

  2. CryptoApi is not there again?!

  3. Cool, making things simple has always been one of Delphi’s strengths.

  4. Note that you don’t need to call CoInitializeSecurity, CoSetProxyBlanket does the right job for the IWbemServices interface without side effects on the other COM interfaces.

    Michel

  5. Pingback: Michael Swindell » Exploring XE3 Win API Additions

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