How To Use ADSI to Set Automatic Inheritance of File/Folder Permissions


Summary


File permissions that are set on files and folders using Active Directory Services Interface (ADSI) and the ADSI resource kit utility, ADsSecurity.DLL, do not automatically propagate down the subtree to the existing folders and files.

To accomplish automatic propagation of inheritable Access Control Entries (ACEs) using ADSI, you need to enumerate existing subfolders and files yourself and apply the inheritable ACEs. Alternatively, you can call the SetSecurityInfo or SetNamedSecurityInfo function directly instead of using ADSI.

More Information


The reason that you cannot use ADSI to set ACEs to propagate down to existing files and folders is because ADSSecurity.dll uses the low-level SetFileSecurity function to set the security descriptor on a folder. There is no flag that can be set by using SetFileSecurity to automatically propagate the ACEs down to existing files and folders. The SE_DACL_AUTO_INHERIT_REQ control flag will only set the SE_DACL_AUTO_INHERITED flag in the security descriptor that is associated with the folder.

Automatic propagation of inheritable ACEs is done only when using the high-level SetSecurityInfo or SetNamedSecurityInfo function. These functions propagate the inheritable ACEs (CONTAINER_INHERIT_ACE or OBJECT_INHERIT_ACE) set on a folder to all existing subfolders and files, as long as the child object's DACL is not SE_DACL_PROTECTED. This is done only in the high-level access control implementation by enumerating the subfolders as well as files, and applying all of the inheritable ACEs.

The following sample VB Script demonstrates how to enumerate folders and files and set file permissions using ADSI and ADsSecurity.DLL:
  1. Create a file called SetPerms.vbs and paste the following code:
    '====================================================================
    'SetPerms.vbs
    '====================================================================
    'Variable Declarations
    Dim sec
    Dim sd
    Dim Dacl
    Dim ace
    Dim ace1
    Dim ace2
    Dim oSid
    Dim sidHex

    'Option Explicit

    'Flags: Specifies Inheritance
    const ADS_ACEFLAG_INHERIT_ACE = &h2
    const ADS_ACEFLAG_NO_PROPAGATE_INHERIT_ACE = &h4
    const ADS_ACEFLAG_INHERIT_ONLY_ACE = &h8
    const ADS_ACEFLAG_INHERITED_ACE = &h10
    const ADS_ACEFLAG_VALID_INHERIT_FLAGS = &h1f
    const ADS_ACEFLAG_SUCCESSFUL_ACCESS = &h40
    const ADS_ACEFLAG_FAILED_ACCESS = &h80

    'Permission Type: Allow or Deny
    const ADS_ACETYPE_ACCESS_ALLOWED = &h0
    const ADS_ACETYPE_ACCESS_DENIED = &h1

    'Permissions: Read, Write, FullControl
    const ADS_RIGHT_GENERIC_READ = &h80000000
    const ADS_RIGHT_GENERIC_WRITE = &h40000000
    const ADS_RIGHT_GENERIC_EXECUTE = &h20000000
    const ADS_RIGHT_GENERIC_ALL = &h10000000

    const ADS_SID_RAW = 0
    const ADS_SID_HEXSTRING= 1
    const ADS_SID_SAM = 2
    const ADS_SID_UPN = 3
    const ADS_SID_SDDL = 4
    const ADS_SID_WINNT_PATH = 5
    const ADS_SID_ACTIVE_DIRECTORY_PATH= 6
    const ADS_SID_SID_BINDING = 7
    const fldname = "C:\test2" '<----Change this to the top folder name
    const usrname = "Domain\User" '<---Change this to the user you want to add permissions for

    Dim fso, fldr, fc, f1', fldname, usrname

    ' Get instance of FileSystemObject.
    Set fso = CreateObject("Scripting.FileSystemObject")
    Call ApplyPerms (fldname)
    Set fldr = fso.GetFolder(fldname)

    Recurse fldr ',usrname

    Set fldr = Nothing
    Set fso = Nothing
    wscript.echo "done"
    Wscript.Quit


    Public Sub Recurse( ByRef fldr)', ByRef usrname )
    dim subfolders,files,folder,file
    Set subfolders = fldr.SubFolders
    Set files = fldr.Files

    'Display the path and all of the folders.
    Wscript.Echo ""
    Wscript.Echo fldr.Path

    For Each folder in subfolders
    Wscript.Echo folder.Name

    Call ApplyPerms (folder.path)', usrname)
    Next

    'Display all of the files.
    For Each file in files
    wscript.echo file.name

    Call ApplyPerms (file.path)', usrname)
    Next

    'Recurse all of the subfolders.
    For Each folder in subfolders
    Recurse folder', usrname
    Next

    Set subfolders = Nothing
    Set files = Nothing

    End Sub

    Sub ApplyPerms(ByRef path)' , Byref usrname)

    Set sec = CreateObject("AdsSecurity")
    Set sd = sec.GetSecurityDescriptor("FILE://" & path)
    Set Dacl = sd.DiscretionaryAcl

    Set oSid = CreateObject("AdsSid")
    oSid.SetAs ADS_SID_SAM, Cstr(usrname)
    sidHex = oSid.GetAs(ADS_SID_SDDL)
    Wscript.Echo sidHex

    '----Add a new ACE so User has Full Control on Files.
    Set ace1 = CreateObject ("AccessControlEntry")
    ace1.Trustee = sidHex
    ace1.AccessMask = ADS_RIGHT_GENERIC_ALL
    ace1.AceType = ADS_ACETYPE_ACCESS_ALLOWED
    ace1.AceFlags = ADS_ACEFLAG_INHERIT_ACE Or ADS_ACEFLAG_INHERIT_ONLY_ACE Or 1
    dacl.AddAce ace1

    '----Add a new ACE so User has Full Control on Folders.
    Set ace2 = CreateObject ("AccessControlEntry")
    ace2.Trustee = sidHex
    ace2.AccessMask = ADS_RIGHT_GENERIC_ALL
    ace2.AceType = ADS_ACETYPE_ACCESS_ALLOWED
    ace2.AceFlags = ADS_ACEFLAG_INHERIT_ACE Or 1
    dacl.AddAce ace2


    sd.DiscretionaryAcl = dacl
    sec.SetSecurityDescriptor sd

    End Sub
  2. Set the constant "fldname" to the folder where you want to start applying the permissions.
  3. Set the constant "usrname" to the name of the Domain account that you are adding the permissions for.
  4. Register ADsSecurity.dll (which is in the Platform SDK) by running regsvr32 ADsSecurity.dll at a command prompt.
  5. Run SetPerms.vbs by double-clicking it on a computer that has Windows Scripting Host (WSH) installed.

References


For operating system specific ADSI run-time downloads and additional information, see the following Microsoft Web site: The ADsSecurity.dll file is available as a resource kit object at the Platform SDK documentation in the ADSI SDK.

For more information on Windows Scripting Host, see the following article:
188135 Description of Windows Script Host (WSH)