Source code for plaso.parsers.fseventsd

# -*- coding: utf-8 -*-
"""Parsers for MacOS fseventsd files."""

from __future__ import unicode_literals

from dfdatetime import semantic_time as dfdatetime_semantic_time

from dfvfs.resolver import resolver as path_spec_resolver

from plaso.containers import events
from plaso.containers import time_events
from plaso.lib import definitions
from plaso.lib import errors
from plaso.lib import specification
from plaso.parsers import dtfabric_parser
from plaso.parsers import manager


[docs]class FseventsdEventData(events.EventData): """MacOS file system event (fseventsd) event data Attributes: event_identifier (int): the record event identifier. flags (int): flags stored in the record. node_identifier (int): file system node identifier related to the file system event. path (str): path recorded in the fseventsd record. """ DATA_TYPE = 'macos:fseventsd:record' def __init__(self): """Initializes an Fseventsd event data.""" super(FseventsdEventData, self).__init__(data_type=self.DATA_TYPE) self.event_identifier = None self.flags = None self.node_identifier = None self.path = None
[docs]class FseventsdParser(dtfabric_parser.DtFabricBaseParser): """Parser for fseventsd files. This parser supports both version 1 and version 2 fseventsd files. Refer to http://nicoleibrahim.com/apple-fsevents-forensics/ for details. """ NAME = 'fseventsd' DESCRIPTION = 'Parser for fseventsd files.' # The version 1 format was used in Mac OS X 10.5 (Leopard) through macOS 10.12 # (Sierra). _DLS_V1_SIGNATURE = b'1SLD' # The version 2 format was introduced in MacOS High Sierra (10.13). _DLS_V2_SIGNATURE = b'2SLD' _DLS_SIGNATURES = [_DLS_V1_SIGNATURE, _DLS_V2_SIGNATURE] _DEFINITION_FILE = 'fseventsd.yaml'
[docs] @classmethod def GetFormatSpecification(cls): """Retrieves the format specification. Returns: FormatSpecification: format specification. """ format_specification = specification.FormatSpecification(cls.NAME) format_specification.AddNewSignature(cls._DLS_V1_SIGNATURE, offset=0) format_specification.AddNewSignature(cls._DLS_V2_SIGNATURE, offset=0) return format_specification
def _ParseDLSPageHeader(self, file_object, page_offset): """Parses a DLS page header from a file-like object. Args: file_object (file): file-like object to read the header from. page_offset (int): offset of the start of the page header, relative to the start of the file. Returns: tuple: containing: dls_page_header: parsed record structure. int: header size. Raises: ParseError: when the header cannot be parsed. """ page_header_map = self._GetDataTypeMap('dls_page_header') try: page_header, page_size = self._ReadStructureFromFileObject( file_object, page_offset, page_header_map) except (ValueError, errors.ParseError) as exception: raise errors.ParseError( 'Unable to parse page header at offset: 0x{0:08x} ' 'with error: {1!s}'.format(page_offset, exception)) if page_header.signature not in self._DLS_SIGNATURES: raise errors.UnableToParseFile( 'Unsupported page header signature at offset: 0x{0:08x}'.format( page_offset)) return page_header, page_size def _BuildEventData(self, record): """Builds an FseventsdData object from a parsed structure. Args: record (dls_record_v1|dls_record_v2): parsed record structure. Returns: FseventsdEventData: event data attribute container. """ event_data = FseventsdEventData() event_data.path = record.path event_data.flags = record.event_flags event_data.event_identifier = record.event_identifier # Node identifier is only set in DLS V2 records. event_data.node_identifier = getattr(record, 'node_identifier', None) return event_data def _GetParentModificationTime(self, gzip_file_entry): """Retrieves the modification time of the file entry's parent file. Note that this retrieves the time from the file entry of the parent of the gzip file entry's path spec, which is different from trying to retrieve it from the gzip file entry's parent file entry. It would be preferable to retrieve the modification time from the metadata in the gzip file itself, but it appears to not be set when the file is written by fseventsd. Args: gzip_file_entry (dfvfs.FileEntry): file entry of the gzip file containing the fseventsd data. Returns: dfdatetime.DateTimeValues: parent modification time, or None if not available. """ parent_file_entry = path_spec_resolver.Resolver.OpenFileEntry( gzip_file_entry.path_spec.parent) if not parent_file_entry: return None return parent_file_entry.modification_time
[docs] def ParseFileObject(self, parser_mediator, file_object): """Parses an fseventsd file. Args: parser_mediator (ParserMediator): parser mediator. file_object (dfvfs.FileIO): a file-like object. Raises: UnableToParseFile: when the header cannot be parsed. """ page_header_map = self._GetDataTypeMap('dls_page_header') try: page_header, file_offset = self._ReadStructureFromFileObject( file_object, 0, page_header_map) except (ValueError, errors.ParseError) as exception: raise errors.UnableToParseFile( 'Unable to parse page header with error: {0!s}'.format( exception)) if page_header.signature not in self._DLS_SIGNATURES: raise errors.UnableToParseFile('Invalid file signature') current_page_end = page_header.page_size file_entry = parser_mediator.GetFileEntry() date_time = self._GetParentModificationTime(file_entry) # TODO: Change this to use a more representative time definition (time span) # when https://github.com/log2timeline/dfdatetime/issues/65 is resolved. if date_time: timestamp_description = definitions.TIME_DESCRIPTION_RECORDED else: date_time = dfdatetime_semantic_time.SemanticTime('Not set') timestamp_description = definitions.TIME_DESCRIPTION_NOT_A_TIME event = time_events.DateTimeValuesEvent(date_time, timestamp_description) file_size = file_object.get_size() while file_offset < file_size: if file_offset >= current_page_end: try: page_header, header_size = self._ParseDLSPageHeader( file_object, file_offset) except errors.ParseError as exception: parser_mediator.ProduceExtractionWarning( 'Unable to parse page header with error: {0!s}'.format( exception)) break current_page_end += page_header.page_size file_offset += header_size continue if page_header.signature == self._DLS_V1_SIGNATURE: record_map = self._GetDataTypeMap('dls_record_v1') else: record_map = self._GetDataTypeMap('dls_record_v2') try: record, record_length = self._ReadStructureFromFileObject( file_object, file_offset, record_map) file_offset += record_length except (ValueError, errors.ParseError) as exception: parser_mediator.ProduceExtractionWarning( 'Unable to parse page record with error: {0!s}'.format( exception)) break event_data = self._BuildEventData(record) parser_mediator.ProduceEventWithEventData(event, event_data)
manager.ParsersManager.RegisterParser(FseventsdParser)