# -*- coding: utf-8 -*-
"""Text plugin for MacOS Application firewall log (appfirewall.log) files."""
import pyparsing
from dfdatetime import time_elements as dfdatetime_time_elements
from plaso.containers import events
from plaso.lib import dateless_helper
from plaso.lib import errors
from plaso.parsers import text_parser
from plaso.parsers.text_plugins import interface
[docs]
class MacOSAppFirewallLogEventData(events.EventData):
"""MacOS Application firewall log (appfirewall.log) file event data.
Attributes:
action (str): action.
added_time (dfdatetime.DateTimeValues): date and time the log entry
was added.
agent (str): agent that save the log.
computer_name (str): name of the computer.
process_name (str): name of the entity that tried to do the action.
status (str): saved status action.
"""
DATA_TYPE = 'macos:appfirewall_log:entry'
[docs]
def __init__(self):
"""Initializes event data."""
super(MacOSAppFirewallLogEventData, self).__init__(data_type=self.DATA_TYPE)
self.action = None
self.added_time = None
self.agent = None
self.computer_name = None
self.process_name = None
self.status = None
[docs]
class MacOSAppFirewallTextPlugin(
interface.TextPlugin, dateless_helper.DateLessLogFormatHelper):
"""Text plugin for MacOS Application firewall log (appfirewall.log) files."""
NAME = 'mac_appfirewall_log'
DATA_FORMAT = 'MacOS Application firewall log (appfirewall.log) file'
ENCODING = 'utf-8'
_ONE_OR_TWO_DIGITS = pyparsing.Word(pyparsing.nums, max=2).set_parse_action(
lambda tokens: int(tokens[0], 10))
_TWO_DIGITS = pyparsing.Word(pyparsing.nums, exact=2).set_parse_action(
lambda tokens: int(tokens[0], 10))
_THREE_LETTERS = pyparsing.Word(pyparsing.alphas, exact=3)
# Define how a log line should look like.
# Example: 'Nov 2 04:07:35 DarkTemplar-2.local socketfilterfw[112] '
# '<Info>: Dropbox: Allow (in:0 out:2)'
# INFO: process_name is going to have a white space at the beginning.
_DATE_TIME = (
_THREE_LETTERS +
_ONE_OR_TWO_DIGITS +
_TWO_DIGITS + pyparsing.Suppress(':') +
_TWO_DIGITS + pyparsing.Suppress(':') + _TWO_DIGITS)
_REPORTER_CHARACTERS = ''.join(
[c for c in pyparsing.printables if c not in [':', '[', '<']])
_PROCESS_IDENTIFIER = pyparsing.Word(pyparsing.nums, max=5).set_parse_action(
lambda tokens: int(tokens[0], 10))
_AGENT = pyparsing.Combine(
pyparsing.Word(_REPORTER_CHARACTERS) + pyparsing.Literal('[') +
_PROCESS_IDENTIFIER + pyparsing.Literal(']'))
_LOG_LINE_START = (
_DATE_TIME.set_results_name('date_time') +
pyparsing.Word(pyparsing.printables).set_results_name('computer_name') +
_AGENT.set_results_name('agent'))
_END_OF_LINE = pyparsing.Suppress(pyparsing.LineEnd())
_LOG_LINE = (
_LOG_LINE_START +
pyparsing.Suppress('<') +
pyparsing.CharsNotIn('>').set_results_name('status') +
pyparsing.Suppress('>:') +
pyparsing.CharsNotIn(':').set_results_name('process_name') +
pyparsing.Suppress(': ') +
pyparsing.restOfLine().set_results_name('action') + _END_OF_LINE)
# Repeated line.
# Example: Nov 29 22:18:29 --- last message repeated 1 time ---
_REPEATED_LOG_LINE_END = pyparsing.Suppress('---') + _END_OF_LINE
_REPEATED_LOG_LINE = (
_DATE_TIME.set_results_name('date_time') +
pyparsing.Suppress('---') + pyparsing.SkipTo(_REPEATED_LOG_LINE_END) +
_REPEATED_LOG_LINE_END)
_LINE_STRUCTURES = [
('log_line', _LOG_LINE),
('repeated_log_line', _REPEATED_LOG_LINE)]
VERIFICATION_GRAMMAR = _LOG_LINE_START + pyparsing.Literal(
'<Error>: Logging: creating /var/log/appfirewall.log') + _END_OF_LINE
[docs]
def __init__(self):
"""Initializes a text parser plugin."""
super(MacOSAppFirewallTextPlugin, self).__init__()
self._repeated_structure = None
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')
# If the actual entry is a repeated entry, we take the basic information
# from the previous entry, but use the timestamp from the actual entry.
if key == 'log_line':
self._repeated_structure = structure
else:
structure = self._repeated_structure
event_data = MacOSAppFirewallLogEventData()
event_data.action = self._GetValueFromStructure(structure, 'action')
event_data.added_time = self._ParseTimeElements(time_elements_structure)
event_data.agent = self._GetValueFromStructure(structure, 'agent')
event_data.computer_name = self._GetValueFromStructure(
structure, 'computer_name')
event_data.process_name = self._GetStringValueFromStructure(
structure, 'process_name')
event_data.status = self._GetValueFromStructure(structure, 'status')
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 = (
time_elements_structure)
month = self._GetMonthFromString(month_string)
self._UpdateYear(month)
relative_year = self._GetRelativeYear()
time_elements_tuple = (
relative_year, month, day_of_month, hours, minutes, seconds)
return dfdatetime_time_elements.TimeElements(
is_delta=True, time_elements_tuple=time_elements_tuple)
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 plugin, False otherwise.
"""
try:
structure = self._VerifyString(text_reader.lines)
except errors.ParseError:
return False
self._SetEstimatedYear(parser_mediator)
time_elements_structure = self._GetValueFromStructure(
structure, 'date_time')
try:
self._ParseTimeElements(time_elements_structure)
except errors.ParseError:
return False
self._repeated_structure = None
return True
text_parser.TextLogParser.RegisterPlugin(MacOSAppFirewallTextPlugin)