QueryUsersOnEncryptedFile function (winefs.h)

Retrieves a list of users for the specified file.


DWORD QueryUsersOnEncryptedFile(
  LPCWSTR                           lpFileName,



The name of the file.


A pointer to a ENCRYPTION_CERTIFICATE_HASH_LIST structure that receives the list of users.

Return value

If the function succeeds, the return value is ERROR_SUCCESS.

If the function fails, the return value is a system error code. For a complete list of error codes, see System Error Codes or the header file WinError.h.


When the list of users is no longer needed, call the FreeEncryptionCertificateHashList function to free the list.

In Windows 8, Windows Server 2012, and later, this function is supported by the following technologies.

Technology Supported
Server Message Block (SMB) 3.0 protocol Yes
SMB 3.0 Transparent Failover (TFO) No
SMB 3.0 with Scale-out File Shares (SO) No
Cluster Shared Volume File System (CsvFS) No
Resilient File System (ReFS) No

SMB 3.0 does not support EFS on shares with continuous availability capability.


Minimum supported client Windows XP Professional [desktop apps only]
Minimum supported server Windows Server 2003 [desktop apps only]
Target Platform Windows
Header winefs.h (include Windows.h)
Library Advapi32.lib
DLL Advapi32.dll
API set ext-ms-win-advapi32-encryptedfile-l1-1-0 (introduced in Windows 8)

See also


File Encryption

File Management Functions