Windows shell link file: Python parsing library

Windows .lnk files (AKA "shell link" file) are most frequently used in Windows shell to create "shortcuts" to another files, usually for purposes of running a program from some other directory, sometimes with certain preconfigured arguments and some other options.

This page hosts a formal specification of Windows shell link file using Kaitai Struct. This specification can be automatically translated into a variety of programming languages to get a parsing library.

Usage

Runtime 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 kaitaistruct

Code

Parse a local file and get structure in memory:

data = WindowsLnkFile.from_file("path/to/local/file.lnk")

Or parse structure from a bytes:

from kaitaistruct import KaitaiStream, BytesIO

raw = b"\x00\x01\x02..."
data = WindowsLnkFile(KaitaiStream(BytesIO(raw)))

After that, one can get various attributes from the structure by invoking getter methods like:

data.header # => get header

Python source code to parse Windows shell link file

windows_lnk_file.py

# This is a generated file! Please edit source .ksy file and use kaitai-struct-compiler to rebuild
# type: ignore

import kaitaistruct
from kaitaistruct import KaitaiStruct, KaitaiStream, BytesIO
import windows_shell_items
from enum import IntEnum


if getattr(kaitaistruct, 'API_VERSION', (0, 9)) < (0, 11):
    raise Exception("Incompatible Kaitai Struct Python API: 0.11 or later is required, but you have %s" % (kaitaistruct.__version__))

class WindowsLnkFile(KaitaiStruct):
    """Windows .lnk files (AKA "shell link" file) are most frequently used
    in Windows shell to create "shortcuts" to another files, usually for
    purposes of running a program from some other directory, sometimes
    with certain preconfigured arguments and some other options.
    
    .. seealso::
       Source - https://winprotocoldoc.blob.core.windows.net/productionwindowsarchives/MS-SHLLINK/[MS-SHLLINK].pdf
    """

    class DriveTypes(IntEnum):
        unknown = 0
        no_root_dir = 1
        removable = 2
        fixed = 3
        remote = 4
        cdrom = 5
        ramdisk = 6

    class WindowState(IntEnum):
        normal = 1
        maximized = 3
        min_no_active = 7
    def __init__(self, _io, _parent=None, _root=None):
        super(WindowsLnkFile, self).__init__(_io)
        self._parent = _parent
        self._root = _root or self
        self._read()

    def _read(self):
        self.header = WindowsLnkFile.FileHeader(self._io, self, self._root)
        if self.header.flags.has_link_target_id_list:
            pass
            self.target_id_list = WindowsLnkFile.LinkTargetIdList(self._io, self, self._root)

        if self.header.flags.has_link_info:
            pass
            self.info = WindowsLnkFile.LinkInfo(self._io, self, self._root)

        if self.header.flags.has_name:
            pass
            self.name = WindowsLnkFile.StringData(self._io, self, self._root)

        if self.header.flags.has_rel_path:
            pass
            self.rel_path = WindowsLnkFile.StringData(self._io, self, self._root)

        if self.header.flags.has_work_dir:
            pass
            self.work_dir = WindowsLnkFile.StringData(self._io, self, self._root)

        if self.header.flags.has_arguments:
            pass
            self.arguments = WindowsLnkFile.StringData(self._io, self, self._root)

        if self.header.flags.has_icon_location:
            pass
            self.icon_location = WindowsLnkFile.StringData(self._io, self, self._root)



    def _fetch_instances(self):
        pass
        self.header._fetch_instances()
        if self.header.flags.has_link_target_id_list:
            pass
            self.target_id_list._fetch_instances()

        if self.header.flags.has_link_info:
            pass
            self.info._fetch_instances()

        if self.header.flags.has_name:
            pass
            self.name._fetch_instances()

        if self.header.flags.has_rel_path:
            pass
            self.rel_path._fetch_instances()

        if self.header.flags.has_work_dir:
            pass
            self.work_dir._fetch_instances()

        if self.header.flags.has_arguments:
            pass
            self.arguments._fetch_instances()

        if self.header.flags.has_icon_location:
            pass
            self.icon_location._fetch_instances()


    class FileHeader(KaitaiStruct):
        """
        .. seealso::
           Section 2.1 - https://winprotocoldoc.blob.core.windows.net/productionwindowsarchives/MS-SHLLINK/[MS-SHLLINK].pdf
        """
        def __init__(self, _io, _parent=None, _root=None):
            super(WindowsLnkFile.FileHeader, self).__init__(_io)
            self._parent = _parent
            self._root = _root
            self._read()

        def _read(self):
            self.len_header = self._io.read_bytes(4)
            if not self.len_header == b"\x4C\x00\x00\x00":
                raise kaitaistruct.ValidationNotEqualError(b"\x4C\x00\x00\x00", self.len_header, self._io, u"/types/file_header/seq/0")
            self.link_clsid = self._io.read_bytes(16)
            if not self.link_clsid == b"\x01\x14\x02\x00\x00\x00\x00\x00\xC0\x00\x00\x00\x00\x00\x00\x46":
                raise kaitaistruct.ValidationNotEqualError(b"\x01\x14\x02\x00\x00\x00\x00\x00\xC0\x00\x00\x00\x00\x00\x00\x46", self.link_clsid, self._io, u"/types/file_header/seq/1")
            self._raw_flags = self._io.read_bytes(4)
            _io__raw_flags = KaitaiStream(BytesIO(self._raw_flags))
            self.flags = WindowsLnkFile.LinkFlags(_io__raw_flags, self, self._root)
            self.file_attrs = self._io.read_u4le()
            self.time_creation = self._io.read_u8le()
            self.time_access = self._io.read_u8le()
            self.time_write = self._io.read_u8le()
            self.target_file_size = self._io.read_u4le()
            self.icon_index = self._io.read_s4le()
            self.show_command = KaitaiStream.resolve_enum(WindowsLnkFile.WindowState, self._io.read_u4le())
            self.hotkey = self._io.read_u2le()
            self.reserved = self._io.read_bytes(10)
            if not self.reserved == b"\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00":
                raise kaitaistruct.ValidationNotEqualError(b"\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00", self.reserved, self._io, u"/types/file_header/seq/11")


        def _fetch_instances(self):
            pass
            self.flags._fetch_instances()


    class LinkFlags(KaitaiStruct):
        """
        .. seealso::
           Section 2.1.1 - https://winprotocoldoc.blob.core.windows.net/productionwindowsarchives/MS-SHLLINK/[MS-SHLLINK].pdf
        """
        def __init__(self, _io, _parent=None, _root=None):
            super(WindowsLnkFile.LinkFlags, self).__init__(_io)
            self._parent = _parent
            self._root = _root
            self._read()

        def _read(self):
            self.is_unicode = self._io.read_bits_int_be(1) != 0
            self.has_icon_location = self._io.read_bits_int_be(1) != 0
            self.has_arguments = self._io.read_bits_int_be(1) != 0
            self.has_work_dir = self._io.read_bits_int_be(1) != 0
            self.has_rel_path = self._io.read_bits_int_be(1) != 0
            self.has_name = self._io.read_bits_int_be(1) != 0
            self.has_link_info = self._io.read_bits_int_be(1) != 0
            self.has_link_target_id_list = self._io.read_bits_int_be(1) != 0
            self._unnamed8 = self._io.read_bits_int_be(16)
            self.reserved = self._io.read_bits_int_be(5)
            self.keep_local_id_list_for_unc_target = self._io.read_bits_int_be(1) != 0
            self._unnamed11 = self._io.read_bits_int_be(2)


        def _fetch_instances(self):
            pass


    class LinkInfo(KaitaiStruct):
        """
        .. seealso::
           Section 2.3 - https://winprotocoldoc.blob.core.windows.net/productionwindowsarchives/MS-SHLLINK/[MS-SHLLINK].pdf
        """
        def __init__(self, _io, _parent=None, _root=None):
            super(WindowsLnkFile.LinkInfo, self).__init__(_io)
            self._parent = _parent
            self._root = _root
            self._read()

        def _read(self):
            self.len_all = self._io.read_u4le()
            self._raw_all = self._io.read_bytes(self.len_all - 4)
            _io__raw_all = KaitaiStream(BytesIO(self._raw_all))
            self.all = WindowsLnkFile.LinkInfo.All(_io__raw_all, self, self._root)


        def _fetch_instances(self):
            pass
            self.all._fetch_instances()

        class All(KaitaiStruct):
            """
            .. seealso::
               Section 2.3 - https://winprotocoldoc.blob.core.windows.net/productionwindowsarchives/MS-SHLLINK/[MS-SHLLINK].pdf
            """
            def __init__(self, _io, _parent=None, _root=None):
                super(WindowsLnkFile.LinkInfo.All, self).__init__(_io)
                self._parent = _parent
                self._root = _root
                self._read()

            def _read(self):
                self.len_header = self._io.read_u4le()
                self._raw_header = self._io.read_bytes(self.len_header - 8)
                _io__raw_header = KaitaiStream(BytesIO(self._raw_header))
                self.header = WindowsLnkFile.LinkInfo.Header(_io__raw_header, self, self._root)


            def _fetch_instances(self):
                pass
                self.header._fetch_instances()
                _ = self.local_base_path
                if hasattr(self, '_m_local_base_path'):
                    pass

                _ = self.volume_id
                if hasattr(self, '_m_volume_id'):
                    pass
                    self._m_volume_id._fetch_instances()


            @property
            def local_base_path(self):
                if hasattr(self, '_m_local_base_path'):
                    return self._m_local_base_path

                if self.header.flags.has_volume_id_and_local_base_path:
                    pass
                    _pos = self._io.pos()
                    self._io.seek(self.header.ofs_local_base_path - 4)
                    self._m_local_base_path = self._io.read_bytes_term(0, False, True, True)
                    self._io.seek(_pos)

                return getattr(self, '_m_local_base_path', None)

            @property
            def volume_id(self):
                if hasattr(self, '_m_volume_id'):
                    return self._m_volume_id

                if self.header.flags.has_volume_id_and_local_base_path:
                    pass
                    _pos = self._io.pos()
                    self._io.seek(self.header.ofs_volume_id - 4)
                    self._m_volume_id = WindowsLnkFile.LinkInfo.VolumeIdSpec(self._io, self, self._root)
                    self._io.seek(_pos)

                return getattr(self, '_m_volume_id', None)


        class Header(KaitaiStruct):
            """
            .. seealso::
               Section 2.3 - https://winprotocoldoc.blob.core.windows.net/productionwindowsarchives/MS-SHLLINK/[MS-SHLLINK].pdf
            """
            def __init__(self, _io, _parent=None, _root=None):
                super(WindowsLnkFile.LinkInfo.Header, self).__init__(_io)
                self._parent = _parent
                self._root = _root
                self._read()

            def _read(self):
                self.flags = WindowsLnkFile.LinkInfo.LinkInfoFlags(self._io, self, self._root)
                self.ofs_volume_id = self._io.read_u4le()
                self.ofs_local_base_path = self._io.read_u4le()
                self.ofs_common_net_rel_link = self._io.read_u4le()
                self.ofs_common_path_suffix = self._io.read_u4le()
                if (not (self._io.is_eof())):
                    pass
                    self.ofs_local_base_path_unicode = self._io.read_u4le()

                if (not (self._io.is_eof())):
                    pass
                    self.ofs_common_path_suffix_unicode = self._io.read_u4le()



            def _fetch_instances(self):
                pass
                self.flags._fetch_instances()
                if (not (self._io.is_eof())):
                    pass

                if (not (self._io.is_eof())):
                    pass



        class LinkInfoFlags(KaitaiStruct):
            """
            .. seealso::
               Section 2.3 - https://winprotocoldoc.blob.core.windows.net/productionwindowsarchives/MS-SHLLINK/[MS-SHLLINK].pdf
            """
            def __init__(self, _io, _parent=None, _root=None):
                super(WindowsLnkFile.LinkInfo.LinkInfoFlags, self).__init__(_io)
                self._parent = _parent
                self._root = _root
                self._read()

            def _read(self):
                self.reserved1 = self._io.read_bits_int_be(6)
                self.has_common_net_rel_link = self._io.read_bits_int_be(1) != 0
                self.has_volume_id_and_local_base_path = self._io.read_bits_int_be(1) != 0
                self.reserved2 = self._io.read_bits_int_be(24)


            def _fetch_instances(self):
                pass


        class VolumeIdBody(KaitaiStruct):
            """
            .. seealso::
               Section 2.3.1 - https://winprotocoldoc.blob.core.windows.net/productionwindowsarchives/MS-SHLLINK/[MS-SHLLINK].pdf
            """
            def __init__(self, _io, _parent=None, _root=None):
                super(WindowsLnkFile.LinkInfo.VolumeIdBody, self).__init__(_io)
                self._parent = _parent
                self._root = _root
                self._read()

            def _read(self):
                self.drive_type = KaitaiStream.resolve_enum(WindowsLnkFile.DriveTypes, self._io.read_u4le())
                self.drive_serial_number = self._io.read_u4le()
                self.ofs_volume_label = self._io.read_u4le()
                if self.is_unicode:
                    pass
                    self.ofs_volume_label_unicode = self._io.read_u4le()



            def _fetch_instances(self):
                pass
                if self.is_unicode:
                    pass

                _ = self.volume_label_ansi
                if hasattr(self, '_m_volume_label_ansi'):
                    pass


            @property
            def is_unicode(self):
                if hasattr(self, '_m_is_unicode'):
                    return self._m_is_unicode

                self._m_is_unicode = self.ofs_volume_label == 20
                return getattr(self, '_m_is_unicode', None)

            @property
            def volume_label_ansi(self):
                if hasattr(self, '_m_volume_label_ansi'):
                    return self._m_volume_label_ansi

                if (not (self.is_unicode)):
                    pass
                    _pos = self._io.pos()
                    self._io.seek(self.ofs_volume_label - 4)
                    self._m_volume_label_ansi = (self._io.read_bytes_term(0, False, True, True)).decode(u"IBM437")
                    self._io.seek(_pos)

                return getattr(self, '_m_volume_label_ansi', None)


        class VolumeIdSpec(KaitaiStruct):
            """
            .. seealso::
               Section 2.3.1 - https://winprotocoldoc.blob.core.windows.net/productionwindowsarchives/MS-SHLLINK/[MS-SHLLINK].pdf
            """
            def __init__(self, _io, _parent=None, _root=None):
                super(WindowsLnkFile.LinkInfo.VolumeIdSpec, self).__init__(_io)
                self._parent = _parent
                self._root = _root
                self._read()

            def _read(self):
                self.len_all = self._io.read_u4le()
                self._raw_body = self._io.read_bytes(self.len_all - 4)
                _io__raw_body = KaitaiStream(BytesIO(self._raw_body))
                self.body = WindowsLnkFile.LinkInfo.VolumeIdBody(_io__raw_body, self, self._root)


            def _fetch_instances(self):
                pass
                self.body._fetch_instances()



    class LinkTargetIdList(KaitaiStruct):
        """
        .. seealso::
           Section 2.2 - https://winprotocoldoc.blob.core.windows.net/productionwindowsarchives/MS-SHLLINK/[MS-SHLLINK].pdf
        """
        def __init__(self, _io, _parent=None, _root=None):
            super(WindowsLnkFile.LinkTargetIdList, self).__init__(_io)
            self._parent = _parent
            self._root = _root
            self._read()

        def _read(self):
            self.len_id_list = self._io.read_u2le()
            self._raw_id_list = self._io.read_bytes(self.len_id_list)
            _io__raw_id_list = KaitaiStream(BytesIO(self._raw_id_list))
            self.id_list = windows_shell_items.WindowsShellItems(_io__raw_id_list)


        def _fetch_instances(self):
            pass
            self.id_list._fetch_instances()


    class StringData(KaitaiStruct):
        def __init__(self, _io, _parent=None, _root=None):
            super(WindowsLnkFile.StringData, self).__init__(_io)
            self._parent = _parent
            self._root = _root
            self._read()

        def _read(self):
            self.chars_str = self._io.read_u2le()
            self.str = (self._io.read_bytes(self.chars_str * 2)).decode(u"UTF-16LE")


        def _fetch_instances(self):
            pass