Source code for plaso.parsers.text_plugins.sophos_av

# -*- coding: utf-8 -*-
"""Text parser plugin for Sophos anti-virus logs (SAV.txt) files.

Also see:

import pyparsing

from dfdatetime import time_elements as dfdatetime_time_elements

from plaso.containers import events
from plaso.lib import errors
from plaso.parsers import text_parser
from plaso.parsers.text_plugins import interface

[docs]class SophosAVLogEventData(events.EventData): """Sophos anti-virus log event data. Attributes: added_time (dfdatetime.DateTimeValues): date and time the log entry was added. text (str): Sophos anti-virus log message. """ DATA_TYPE = 'sophos:av:log' def __init__(self): """Initializes event data.""" super(SophosAVLogEventData, self).__init__(data_type=self.DATA_TYPE) self.added_time = None self.text = None
[docs]class SophosAVLogTextPlugin(interface.TextPlugin): """Text parser plugin for Sophos anti-virus logs (SAV.txt) files.""" NAME = 'sophos_av' DATA_FORMAT = 'Sophos anti-virus log file (SAV.txt) file' ENCODING = 'utf-16-le' _TWO_DIGITS = pyparsing.Word(pyparsing.nums, exact=2).setParseAction( lambda tokens: int(tokens[0], 10)) _FOUR_DIGITS = pyparsing.Word(pyparsing.nums, exact=4).setParseAction( lambda tokens: int(tokens[0], 10)) # Date and time values are formatted as: YYYYMMDD hhmmss # For example: 20100720 183814 _DATE_TIME = pyparsing.Group( _FOUR_DIGITS + _TWO_DIGITS + _TWO_DIGITS + _TWO_DIGITS + _TWO_DIGITS + _TWO_DIGITS) _END_OF_LINE = pyparsing.Suppress(pyparsing.LineEnd()) _LOG_LINE = ( _DATE_TIME.setResultsName('date_time') + pyparsing.restOfLine().setResultsName('text') + _END_OF_LINE) _LINE_STRUCTURES = [('log_line', _LOG_LINE)] VERIFICATION_GRAMMAR = _LOG_LINE def _ParseRecord(self, parser_mediator, key, structure): """Parses a pyparsing structure. Args: parser_mediator (ParserMediator): mediates interactions between parsers and other components, such as storage and dfVFS. key (str): name of the parsed structure. structure (pyparsing.ParseResults): tokens from a parsed log line. Raises: ParseError: if the structure cannot be parsed. """ time_elements_structure = self._GetValueFromStructure( structure, 'date_time') event_data = SophosAVLogEventData() event_data.added_time = self._ParseTimeElements(time_elements_structure) event_data.text = self._GetStringValueFromStructure(structure, 'text') parser_mediator.ProduceEventData(event_data) def _ParseTimeElements(self, time_elements_structure): """Parses date and time elements of a log line. Args: time_elements_structure (pyparsing.ParseResults): date and time elements of a log line. Returns: dfdatetime.TimeElements: date and time value. Raises: ParseError: if a valid date and time value cannot be derived from the time elements. """ try: # Ensure time_elements_tuple is not a pyparsing.ParseResults otherwise # copy.deepcopy() of the dfDateTime object will fail on Python 3.8 with: # "TypeError: 'str' object is not callable" due to pyparsing.ParseResults # overriding __getattr__ with a function that returns an empty string # when named token does not exists. year, month, day_of_month, hours, minutes, seconds = ( time_elements_structure) time_elements_tuple = (year, month, day_of_month, hours, minutes, seconds) date_time = dfdatetime_time_elements.TimeElements( time_elements_tuple=time_elements_tuple) # TODO: check if date and time values are local time or in UTC. date_time.is_local_time = True return date_time except (TypeError, ValueError) as exception: raise errors.ParseError( 'Unable to parse time elements with error: {0!s}'.format(exception))
[docs] def CheckRequiredFormat(self, parser_mediator, text_reader): """Check if the log record has the minimal structure required by the plugin. Args: parser_mediator (ParserMediator): mediates interactions between parsers and other components, such as storage and dfVFS. text_reader (EncodedTextReader): text reader. Returns: bool: True if this is the correct parser, False otherwise. """ try: structure = self._VerifyString(text_reader.lines) except errors.ParseError: return False time_elements_structure = self._GetValueFromStructure( structure, 'date_time') try: self._ParseTimeElements(time_elements_structure) except ValueError: return False return True