Source code for plaso.parsers.text_plugins.vsftpd

# -*- coding: utf-8 -*-
"""Text parser plugin for vsftpd log files."""

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 VsftpdLogEventData(events.EventData): """vsftpd log event data. Attributes: added_time (dfdatetime.DateTimeValues): date and time the log entry was added. text (str): vsftpd log message. """ DATA_TYPE = 'vsftpd:log' def __init__(self): """Initializes event data.""" super(VsftpdLogEventData, self).__init__(data_type=self.DATA_TYPE) self.added_time = None self.text = None
[docs]class VsftpdLogTextPlugin(interface.TextPlugin): """Text parser plugin for vsftpd log files.""" NAME = 'vsftpd' DATA_FORMAT = 'vsftpd log file' _MONTH_DICT = { 'jan': 1, 'feb': 2, 'mar': 3, 'apr': 4, 'may': 5, 'jun': 6, 'jul': 7, 'aug': 8, 'sep': 9, 'oct': 10, 'nov': 11, 'dec': 12} _ONE_OR_TWO_DIGITS = pyparsing.Word(pyparsing.nums, max=2).setParseAction( lambda tokens: int(tokens[0], 10)) _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)) _THREE_LETTERS = pyparsing.Word(pyparsing.alphas, exact=3) # Date and time values are formatted as: Mon Jun 6 18:43:28 2016 _DATE_TIME = pyparsing.Group( _THREE_LETTERS + _THREE_LETTERS + _ONE_OR_TWO_DIGITS + _TWO_DIGITS + pyparsing.Suppress(':') + _TWO_DIGITS + pyparsing.Suppress(':') + _TWO_DIGITS + _FOUR_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 = VsftpdLogEventData() event_data.added_time = self._ParseTimeElements(time_elements_structure) # TODO: extract pid and username. 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: _, month_string, day_of_month, hours, minutes, seconds, year = ( time_elements_structure) month = self._MONTH_DICT.get(month_string.lower(), 0) time_elements_tuple = (year, month, day_of_month, hours, minutes, seconds) date_time = dfdatetime_time_elements.TimeElements( time_elements_tuple=time_elements_tuple) 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 errors.ParseError: return False return True