Source code for plaso.parsers.bencode_parser

# -*- coding: utf-8 -*-
"""This file contains the Bencode Parser.

Plaso's engine calls BencodeParser when it encounters bencoded files to be
processed, typically seen for BitTorrent data.

from __future__ import unicode_literals

import re
import os

import bencode

from plaso.lib import errors
from plaso.parsers import interface
from plaso.parsers import logger
from plaso.parsers import manager

[docs]class BencodeParser(interface.FileObjectParser): """Deserializes bencoded file; produces a dictionary containing bencoded data. The Plaso engine calls parsers by their Parse() method. The Parse() function deserializes bencoded files using the BitTorrent-bencode library and calls plugins (BencodePlugin) registered through the interface by their Process() to produce event objects. Plugins are how this parser understands the content inside a bencoded file, each plugin holds logic specific to a particular bencoded file. See the bencode_plugins / directory for examples of how bencode plugins are implemented. """ _INITIAL_FILE_OFFSET = None # Regex match for a bencode dictionary followed by a field size. BENCODE_RE = re.compile(b'd[0-9]') NAME = 'bencode' DESCRIPTION = 'Parser for bencoded files.' _plugin_classes = {}
[docs] def ParseFileObject(self, parser_mediator, file_object): """Parses a bencoded file-like object. Args: parser_mediator (ParserMediator): mediates interactions between parsers and other components, such as storage and dfvfs. file_object (dfvfs.FileIO): a file-like object. Raises: UnableToParseFile: when the file cannot be parsed. """, os.SEEK_SET) header = if not self.BENCODE_RE.match(header): raise errors.UnableToParseFile('Not a valid Bencoded file.'), os.SEEK_SET) try: data_object = bencode.bdecode( except (IOError, bencode.BTFailure) as exception: raise errors.UnableToParseFile( '[{0:s}] unable to parse file: {1:s} with error: {2!s}'.format( self.NAME, parser_mediator.GetDisplayName(), exception)) if not data_object: raise errors.UnableToParseFile( '[{0:s}] missing decoded data for file: {1:s}'.format( self.NAME, parser_mediator.GetDisplayName())) for plugin in self._plugins: try: plugin.UpdateChainAndProcess(parser_mediator, data=data_object) except errors.WrongBencodePlugin as exception: logger.debug('[{0:s}] wrong plugin: {1!s}'.format(
self.NAME, exception)) manager.ParsersManager.RegisterParser(BencodeParser)