I need to restrict certain application features based on the location of the current user. Since I have to implement this logic in Delphi, I would prefer not to go overboard with full active directory requests / LDAP.
My current thought is to use DsGetDcName and use the GUID returned in the DOMAIN_CONTROLLER_INFO structure and compare it with a hard-coded constant. It looks like the domain GUID will only change if the domain is recreated, so this will provide the functionality that I want with limited overhead. My only problem is that I cannot find the MSDN documentation that confirms my assumption.
type
EAccessDenied = Exception;
EInvalidOwner = Exception;
EInsufficientBuffer = Exception;
ELibraryNotFound = Exception;
NET_API_STATUS = Integer;
TDomainControllerInfoA = record
DomainControllerName: LPSTR;
DomainControllerAddress: LPSTR;
DomainControllerAddressType: ULONG;
DomainGuid: TGUID;
DomainName: LPSTR;
DnsForestName: LPSTR;
Flags: ULONG;
DcSiteName: LPSTR;
ClientSiteName: LPSTR;
end;
PDomainControllerInfoA = ^TDomainControllerInfoA;
const
NERR_Success = 0;
procedure NetCheck(ErrCode: NET_API_STATUS);
begin
if ErrCode <> NERR_Success then
begin
case ErrCode of
ERROR_ACCESS_DENIED:
raise EAccessDenied.Create('Access is Denied');
ERROR_INVALID_OWNER:
raise EInvalidOwner.Create('Cannot assign the owner of this object.');
ERROR_INSUFFICIENT_BUFFER:
raise EInsufficientBuffer.Create('Buffer passed was too small');
else
raise Exception.Create('Error Code: ' + IntToStr(ErrCode) +
SysErrorMessage(ErrCode));
end;
end;
end;
function IsInternalDomain: Boolean;
var
NTNetDsGetDcName: function(ComputerName, DomainName: PChar; DomainGuid: PGUID; SiteName: PChar; Flags: ULONG; var DomainControllerInfo: PDomainControllerInfoA): NET_API_STATUS; stdcall;
NTNetApiBufferFree: function (lpBuffer: Pointer): NET_API_STATUS; stdcall;
LibHandle: THandle;
DomainControllerInfo: PDomainControllerInfoA;
ErrMode: Word;
const
NTlib = 'NETAPI32.DLL';
DS_IS_FLAT_NAME = $00010000;
DS_RETURN_DNS_NAME = $40000000;
INTERNAL_DOMAIN_GUID: TGUID = '{????????-????-????-????-????????????}';
begin
if Win32Platform = VER_PLATFORM_WIN32_NT then
begin
ErrMode := SetErrorMode(SEM_NOOPENFILEERRORBOX);
LibHandle := LoadLibrary(NTlib);
SetErrorMode(ErrMode);
if LibHandle = 0 then
raise ELibraryNotFound.Create('Unable to map library: ' + NTlib);
try
@NTNetDsGetDcName := GetProcAddress(Libhandle, 'DsGetDcNameA');
@NTNetApiBufferFree := GetProcAddress(Libhandle,'NetApiBufferFree');
try
NetCheck(NTNetDsGetDcName(nil, nil, nil, nil, DS_IS_FLAT_NAME or DS_RETURN_DNS_NAME, DomainControllerInfo));
Result := (DomainControllerInfo.DomainName = 'foo.com') and (CompareMem(@DomainControllerInfo.DomainGuid,@INTERNAL_DOMAIN_GUID, SizeOf(TGuid)));//WideCharToString(pDomain);
finally
NetCheck(NTNetApiBufferFree(DomainControllerInfo));
end;
finally
FreeLibrary(LibHandle);
end;
end
else
Result := False;
end;
ServerFault, .
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