Sudoers Time Stamp file: Python parsing library

This spec can be used to parse sudo time stamp files located in directories such as /run/sudo/ts/$USER or /var/lib/sudo/ts/$USER.

KS implementation details

License: CC0-1.0

This page hosts a formal specification of Sudoers Time Stamp 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 = SudoersTs.from_file("path/to/local/file.bin")

Or parse structure from a bytes:

from kaitaistruct import KaitaiStream, BytesIO

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

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

data.records # => get records

Python source code to parse Sudoers Time Stamp file

sudoers_ts.py

Download 

# 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
from enum import Enum


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 SudoersTs(KaitaiStruct):
    """This spec can be used to parse sudo time stamp files located in directories
    such as /run/sudo/ts/$USER or /var/lib/sudo/ts/$USER.
    
    .. seealso::
       Source - https://www.sudo.ws/docs/man/1.8.27/sudoers_timestamp.man/
    """

    class TsType(Enum):
        global = 1
        tty = 2
        ppid = 3
        lockexcl = 4
    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.records = []
        i = 0
        while not self._io.is_eof():
            self.records.append(SudoersTs.Record(self._io, self, self._root))
            i += 1


    class RecordV2(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.type = KaitaiStream.resolve_enum(SudoersTs.TsType, self._io.read_u2le())
            self.flags = SudoersTs.TsFlag(self._io, self, self._root)
            self.auth_uid = self._io.read_u4le()
            self.sid = self._io.read_u4le()
            self.start_time = SudoersTs.Timespec(self._io, self, self._root)
            self.ts = SudoersTs.Timespec(self._io, self, self._root)
            if self.type == SudoersTs.TsType.tty:
                self.ttydev = self._io.read_u4le()

            if self.type == SudoersTs.TsType.ppid:
                self.ppid = self._io.read_u4le()



    class TsFlag(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.reserved0 = self._io.read_bits_int_be(6)
            self.anyuid = self._io.read_bits_int_be(1) != 0
            self.disabled = self._io.read_bits_int_be(1) != 0
            self.reserved1 = self._io.read_bits_int_be(8)


    class RecordV1(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.type = KaitaiStream.resolve_enum(SudoersTs.TsType, self._io.read_u2le())
            self.flags = SudoersTs.TsFlag(self._io, self, self._root)
            self.auth_uid = self._io.read_u4le()
            self.sid = self._io.read_u4le()
            self.ts = SudoersTs.Timespec(self._io, self, self._root)
            if self.type == SudoersTs.TsType.tty:
                self.ttydev = self._io.read_u4le()

            if self.type == SudoersTs.TsType.ppid:
                self.ppid = self._io.read_u4le()



    class Timespec(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.sec = self._io.read_s8le()
            self.nsec = self._io.read_s8le()


    class Record(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.version = self._io.read_u2le()
            self.len_record = self._io.read_u2le()
            _on = self.version
            if _on == 1:
                self._raw_payload = self._io.read_bytes((self.len_record - 4))
                _io__raw_payload = KaitaiStream(BytesIO(self._raw_payload))
                self.payload = SudoersTs.RecordV1(_io__raw_payload, self, self._root)
            elif _on == 2:
                self._raw_payload = self._io.read_bytes((self.len_record - 4))
                _io__raw_payload = KaitaiStream(BytesIO(self._raw_payload))
                self.payload = SudoersTs.RecordV2(_io__raw_payload, self, self._root)
            else:
                self.payload = self._io.read_bytes((self.len_record - 4))