GetHandleCreatorToken Method

Retrieves the security token associated with the process that opened the file handle.

Syntax

ANSI (Cross Platform)
int64 GetHandleCreatorToken();

Unicode (Windows)
LONG64 GetHandleCreatorToken();
#define MID_CBFILTER_GETHANDLECREATORTOKEN 31

CBFSFILTER_EXTERNAL int CBFSFILTER_CALL CBFSFilter_CBFilter_Do(void *lpObj, int methid, int cparam, void *param[], int cbparam[], int64 *lpllVal);

Remarks

This method can be called within certain events to retrieve the security token associated with the process that opened the file handle. If the query fails, this method returns INVALID_HANDLE_VALUE.

The security token returned by this method can be passed to the Windows API's GetTokenInformation function to obtain more information about the process.

Important: When applications are finished using the returned security token, they must close it using the Windows API's CloseHandle function.

Network Access Notes

Applications monitoring a drive shared on the network may wish to obtain information about the network users accessing it (e.g., account names). Drives can be shared in several modes in Windows, which can affect the information retrievable via the security token this method returns:

  • Authenticated mode, in which case the network redirector (which, in general, is responsible for relaying remote drive requests to and from the system driver) will impersonate the network user, allowing that account's actual information to be retrieved.
  • Guest mode, in which case the retrievable information is for the system's GUEST account.
  • Administrative shares (those which exist by default and whose names end with '$'; e.g., C$, ADMIN$, etc.), in which case the retrievable information is for the LOCAL_SYSTEM account.

Note: This method can only be called within the AfterCreateFile and AfterOpenFile events, and must be called in the same thread that the event was originally fired on. Applications that need the information that this method returns during other events can do the following:

  1. Call this method within the AfterCreateFile or AfterOpenFile event.
  2. Store the information somewhere, and store a reference to it in the event's HandleContext parameter.
  3. In a later event, access the information via the reference stored in HandleContext.
Please refer to the Contexts topic for more information on how to use events' context parameters.

Note: This method cannot be used from CleanupContext event handlers.

Error Handling (C++)

This method returns a Long64 value; after it returns, call the GetLastErrorCode() method to obtain its result code; 0 indicates success, while a non-zero error code indicates that this method encountered an error during its execution. If an error occurs, the GetLastError() method can be called to retrieve the associated error message.

Copyright (c) 2022 Callback Technologies, Inc. - All rights reserved.
CBFS Filter 2020 C++ Edition - Version 20.0 [Build 8317]