Windows Shell Items (AKA "shellbags") is an undocumented set of structures used internally within Windows to identify paths in Windows Folder Hierarchy. It is widely used in Windows Shell (and most visible in File Explorer), both as in-memory and in-file structures. Some formats embed them, namely:
The format is mostly undocumented, and is known to vary between various Windows versions.
This page hosts a formal specification of Windows Shell Items using Kaitai Struct. This specification can be automatically translated into a variety of programming languages to get a parsing library.
All parsing code for Python generated by Kaitai Struct depends on the Python runtime library. You have to install it before you can parse data.
The Python runtime library can be installed from PyPI:
python3 -m pip install kaitaistructParse a local file and get structure in memory:
data = WindowsShellItems.from_file("path/to/local/file.bin")
Or parse structure from a bytes:
from kaitaistruct import KaitaiStream, BytesIO
raw = b"\x00\x01\x02..."
data = WindowsShellItems(KaitaiStream(BytesIO(raw)))
After that, one can get various attributes from the structure by invoking getter methods like:
data.items # => get items
# This is a generated file! Please edit source .ksy file and use kaitai-struct-compiler to rebuild
import kaitaistruct
from kaitaistruct import KaitaiStruct, KaitaiStream, BytesIO
if getattr(kaitaistruct, 'API_VERSION', (0, 9)) < (0, 9):
raise Exception("Incompatible Kaitai Struct Python API: 0.9 or later is required, but you have %s" % (kaitaistruct.__version__))
class WindowsShellItems(KaitaiStruct):
"""Windows Shell Items (AKA "shellbags") is an undocumented set of
structures used internally within Windows to identify paths in
Windows Folder Hierarchy. It is widely used in Windows Shell (and
most visible in File Explorer), both as in-memory and in-file
structures. Some formats embed them, namely:
* Windows Shell link files (.lnk) Windows registry
* Windows registry "ShellBags" keys
The format is mostly undocumented, and is known to vary between
various Windows versions.
.. seealso::
Source - https://github.com/libyal/libfwsi/blob/main/documentation/Windows%20Shell%20Item%20format.asciidoc
"""
def __init__(self, _io, _parent=None, _root=None):
self._io = _io
self._parent = _parent
self._root = _root if _root else self
self._read()
def _read(self):
self.items = []
i = 0
while True:
_ = WindowsShellItems.ShellItem(self._io, self, self._root)
self.items.append(_)
if _.len_data == 0:
break
i += 1
class ShellItemData(KaitaiStruct):
def __init__(self, _io, _parent=None, _root=None):
self._io = _io
self._parent = _parent
self._root = _root if _root else self
self._read()
def _read(self):
self.code = self._io.read_u1()
_on = self.code
if _on == 31:
self.body1 = WindowsShellItems.RootFolderBody(self._io, self, self._root)
_on = (self.code & 112)
if _on == 32:
self.body2 = WindowsShellItems.VolumeBody(self._io, self, self._root)
elif _on == 48:
self.body2 = WindowsShellItems.FileEntryBody(self._io, self, self._root)
class ShellItem(KaitaiStruct):
"""
.. seealso::
Section 2.2.2 - https://winprotocoldoc.blob.core.windows.net/productionwindowsarchives/MS-SHLLINK/[MS-SHLLINK].pdf
"""
def __init__(self, _io, _parent=None, _root=None):
self._io = _io
self._parent = _parent
self._root = _root if _root else self
self._read()
def _read(self):
self.len_data = self._io.read_u2le()
if self.len_data >= 2:
self._raw_data = self._io.read_bytes((self.len_data - 2))
_io__raw_data = KaitaiStream(BytesIO(self._raw_data))
self.data = WindowsShellItems.ShellItemData(_io__raw_data, self, self._root)
class RootFolderBody(KaitaiStruct):
"""
.. seealso::
Source - https://github.com/libyal/libfwsi/blob/main/documentation/Windows%20Shell%20Item%20format.asciidoc#32-root-folder-shell-item
"""
def __init__(self, _io, _parent=None, _root=None):
self._io = _io
self._parent = _parent
self._root = _root if _root else self
self._read()
def _read(self):
self.sort_index = self._io.read_u1()
self.shell_folder_id = self._io.read_bytes(16)
class VolumeBody(KaitaiStruct):
"""
.. seealso::
Source - https://github.com/libyal/libfwsi/blob/main/documentation/Windows%20Shell%20Item%20format.asciidoc#33-volume-shell-item
"""
def __init__(self, _io, _parent=None, _root=None):
self._io = _io
self._parent = _parent
self._root = _root if _root else self
self._read()
def _read(self):
self.flags = self._io.read_u1()
class FileEntryBody(KaitaiStruct):
"""
.. seealso::
Source - https://github.com/libyal/libfwsi/blob/main/documentation/Windows%20Shell%20Item%20format.asciidoc#34-file-entry-shell-item
"""
def __init__(self, _io, _parent=None, _root=None):
self._io = _io
self._parent = _parent
self._root = _root if _root else self
self._read()
def _read(self):
self._unnamed0 = self._io.read_u1()
self.file_size = self._io.read_u4le()
self.last_mod_time = self._io.read_u4le()
self.file_attrs = self._io.read_u2le()
@property
def is_dir(self):
if hasattr(self, '_m_is_dir'):
return self._m_is_dir
self._m_is_dir = (self._parent.code & 1) != 0
return getattr(self, '_m_is_dir', None)
@property
def is_file(self):
if hasattr(self, '_m_is_file'):
return self._m_is_file
self._m_is_file = (self._parent.code & 2) != 0
return getattr(self, '_m_is_file', None)