/mandos/trunk

# -*- mode: python; coding: utf-8; after-save-hook: (lambda () (let ((command (if (and (boundp 'tramp-file-name-structure) (string-match (car tramp-file-name-structure) (buffer-file-name))) (tramp-file-name-localname (tramp-dissect-file-name (buffer-file-name))) (buffer-file-name)))) (if (= (shell-command (format "%s --check" (shell-quote-argument command)) "*Test*") 0) (let ((w (get-buffer-window "*Test*"))) (if w (delete-window w)) (kill-buffer "*Test*")) (display-buffer "*Test*")))); -*-

#

#

# Copyright © 2008-2019 Teddy Hogeborn

# Copyright © 2008-2019 Björn Påhlsson

#

# This file is part of Mandos.

#

# Mandos is free software: you can redistribute it and/or modify it

# under the terms of the GNU General Public License as published by

#     Mandos is distributed in the hope that it will be useful, but

#     WITHOUT ANY WARRANTY; without even the implied warranty of

#

# along with Mandos.  If not, see <http://www.gnu.org/licenses/>.

#

#

try:

    from future_builtins import *

except ImportError:

    pass

import collections

import json

import unittest

import logging

 

import dbus

 

# Show warnings by default

if not sys.warnoptions:

    import warnings

    warnings.simplefilter("default")

 

log = logging.getLogger(sys.argv[0])

logging.basicConfig(level="INFO", # Show info level messages

                    format="%(message)s") # Show basic log messages

 

logging.captureWarnings(True)   # Show warnings via the logging system

 

if sys.version_info.major == 2:

    str = unicode

version = "1.8.3"

 

 

try:

    dbus.OBJECT_MANAGER_IFACE

except AttributeError:

    dbus.OBJECT_MANAGER_IFACE = "org.freedesktop.DBus.ObjectManager"

 

            .format(days="{}T".format(td.days) if td.days else "",

                    hours=td.seconds // 3600,

                    minutes=(td.seconds % 3600) // 60,

                    seconds=td.seconds % 60))

 

 

def rfc3339_duration_to_delta(duration):

    """Parse an RFC 3339 "duration" and return a datetime.timedelta

 

    >>> rfc3339_duration_to_delta("P7D")

    datetime.timedelta(7)

    >>> rfc3339_duration_to_delta("PT60S")

    datetime.timedelta(0, 60)

    >>> rfc3339_duration_to_delta("PT60M")

    datetime.timedelta(0, 3600)

    >>> rfc3339_duration_to_delta("P60M")

    datetime.timedelta(1680)

    >>> rfc3339_duration_to_delta("PT24H")

    datetime.timedelta(1)

    >>> rfc3339_duration_to_delta("P1W")

    datetime.timedelta(7)

    >>> rfc3339_duration_to_delta("PT5M30S")

    datetime.timedelta(0, 330)

    >>> rfc3339_duration_to_delta("P1DT3M20S")

    datetime.timedelta(1, 200)

    >>> # Can not be empty:

    >>> rfc3339_duration_to_delta("")

    Traceback (most recent call last):

    ...

    ValueError: Invalid RFC 3339 duration: u''

    >>> # Must start with "P":

    >>> rfc3339_duration_to_delta("1D")

    Traceback (most recent call last):

    ...

    ValueError: Invalid RFC 3339 duration: u'1D'

    >>> # Must use correct order

    >>> rfc3339_duration_to_delta("PT1S2M")

    Traceback (most recent call last):

    ...

    ValueError: Invalid RFC 3339 duration: u'PT1S2M'

    >>> # Time needs time marker

    >>> rfc3339_duration_to_delta("P1H2S")

    Traceback (most recent call last):

    ...

    ValueError: Invalid RFC 3339 duration: u'P1H2S'

    >>> # Weeks can not be combined with anything else

    >>> rfc3339_duration_to_delta("P1D2W")

    Traceback (most recent call last):

    ...

    ValueError: Invalid RFC 3339 duration: u'P1D2W'

    >>> rfc3339_duration_to_delta("P2W2H")

    Traceback (most recent call last):

    ...

    ValueError: Invalid RFC 3339 duration: u'P2W2H'

    """

 

    # Parsing an RFC 3339 duration with regular expressions is not

    # possible - there would have to be multiple places for the same

    # values, like seconds.  The current code, while more esoteric, is

    # cleaner without depending on a parsing library.  If Python had a

    # built-in library for parsing we would use it, but we'd like to

    # avoid excessive use of external libraries.

 

    # New type for defining tokens, syntax, and semantics all-in-one

    Token = collections.namedtuple("Token", (

        "regexp",  # To match token; if "value" is not None, must have

                   # a "group" containing digits

        "value",   # datetime.timedelta or None

        "followers"))           # Tokens valid after this token

    # RFC 3339 "duration" tokens, syntax, and semantics; taken from

    # the "duration" ABNF definition in RFC 3339, Appendix A.

    token_end = Token(re.compile(r"$"), None, frozenset())

    token_second = Token(re.compile(r"(\d+)S"),

                         datetime.timedelta(seconds=1),

                         frozenset((token_end, )))

    token_minute = Token(re.compile(r"(\d+)M"),

                         datetime.timedelta(minutes=1),

                         frozenset((token_second, token_end)))

    token_hour = Token(re.compile(r"(\d+)H"),

                       datetime.timedelta(hours=1),

                       frozenset((token_minute, token_end)))

    token_time = Token(re.compile(r"T"),

                       None,

                       frozenset((token_hour, token_minute,

                                  token_second)))

    token_day = Token(re.compile(r"(\d+)D"),

                      datetime.timedelta(days=1),

                      frozenset((token_time, token_end)))

    token_month = Token(re.compile(r"(\d+)M"),

                        datetime.timedelta(weeks=4),

                        frozenset((token_day, token_end)))

    token_year = Token(re.compile(r"(\d+)Y"),

                       datetime.timedelta(weeks=52),

                       frozenset((token_month, token_end)))

    token_week = Token(re.compile(r"(\d+)W"),

                       datetime.timedelta(weeks=1),

                       frozenset((token_end, )))

    token_duration = Token(re.compile(r"P"), None,

                           frozenset((token_year, token_month,

                                      token_day, token_time,

                                      token_week)))

    # Define starting values:

    # Value so far

    value = datetime.timedelta()

    found_token = None

    # Following valid tokens

    followers = frozenset((token_duration, ))

    # String left to parse

    s = duration

    # Loop until end token is found

    while found_token is not token_end:

        # Search for any currently valid tokens

        for token in followers:

            match = token.regexp.match(s)

            if match is not None:

                # Token found

                if token.value is not None:

                    # Value found, parse digits

                    factor = int(match.group(1), 10)

                    # Add to value so far

                    value += factor * token.value

                # Strip token from string

                s = token.regexp.sub("", s, 1)

                # Go to found token

                found_token = token

                # Set valid next tokens

                followers = found_token.followers

                break

        else:

            # No currently valid tokens were found

            raise ValueError("Invalid RFC 3339 duration: {!r}"

                             .format(duration))

    # End token found

    return value

 

    """Parse a string and return a datetime.timedelta"""

 

    try:

        return rfc3339_duration_to_delta(interval)

    except ValueError as e:

        log.warning("%s - Parsing as pre-1.6.1 interval instead",

                    ' '.join(e.args))

    return parse_pre_1_6_1_interval(interval)

 

 

def parse_pre_1_6_1_interval(interval):

    """Parse an interval string as documented by Mandos before 1.6.1,

    and return a datetime.timedelta

 

    >>> parse_pre_1_6_1_interval('7d')

    >>> parse_pre_1_6_1_interval('60s')

    >>> parse_pre_1_6_1_interval('60m')

    >>> parse_pre_1_6_1_interval('24h')

    >>> parse_pre_1_6_1_interval('1w')

    >>> parse_pre_1_6_1_interval('5m 30s')

    >>> parse_pre_1_6_1_interval('')

    datetime.timedelta(0)

    >>> # Ignore unknown characters, allow any order and repetitions

    >>> parse_pre_1_6_1_interval('2dxy7zz11y3m5m')

    datetime.timedelta(2, 480, 18000)

 

 

    regexp = re.compile(r"(\d+)([dsmhw]?)")

 

 

class TableOfClients(object):

    tablewords = {

        "Name": "Name",

        "Enabled": "Enabled",

        "Timeout": "Timeout",

        "LastCheckedOK": "Last Successful Check",

        "LastApprovalRequest": "Last Approval Request",

        "Created": "Created",

        "Interval": "Interval",

        "Host": "Host",

        "Fingerprint": "Fingerprint",

        "KeyID": "Key ID",

        "CheckerRunning": "Check Is Running",

        "LastEnabled": "Last Enabled",

        "ApprovalPending": "Approval Is Pending",

        "ApprovedByDefault": "Approved By Default",

        "ApprovalDelay": "Approval Delay",

        "ApprovalDuration": "Approval Duration",

        "Checker": "Checker",

        "ExtendedTimeout": "Extended Timeout",

        "Expires": "Expires",

        "LastCheckerStatus": "Last Checker Status",

    }

 

    def __init__(self, clients, keywords, tablewords=None):

        self.clients = clients

        self.keywords = keywords

        if tablewords is not None:

            self.tablewords = tablewords

 

    def __str__(self):

        return "\n".join(self.rows())

 

    if sys.version_info.major == 2:

        __unicode__ = __str__

        def __str__(self):

            return str(self).encode(locale.getpreferredencoding())

 

    def rows(self):

        format_string = self.row_formatting_string()

        rows = [self.header_line(format_string)]

        rows.extend(self.client_line(client, format_string)

                    for client in self.clients)

        return rows

 

    def row_formatting_string(self):

        "Format string used to format table rows"

        return " ".join("{{{key}:{width}}}".format(

            width=max(len(self.tablewords[key]),

                      *(len(self.string_from_client(client, key))

                        for client in self.clients)),

            key=key)

                        for key in self.keywords)

 

    def string_from_client(self, client, key):

        return self.valuetostring(client[key], key)

 

    @staticmethod

        if isinstance(value, dbus.Boolean):

        return str(value)

 

    def header_line(self, format_string):

        return format_string.format(**self.tablewords)

 

    def client_line(self, client, format_string):

        return format_string.format(

            **{key: self.string_from_client(client, key)

               for key in self.keywords})

 

 

## Classes for commands.

 

# Abstract classes first

class Command(object):

    """Abstract class for commands"""

    def run(self, clients):

        """Normal commands should implement run_on_one_client(), but

        commands which want to operate on all clients at the same time

        can override this run() method instead."""

        for client in clients:

            self.run_on_one_client(client)

 

class PrintCmd(Command):

    """Abstract class for commands printing client details"""

    all_keywords = ("Name", "Enabled", "Timeout", "LastCheckedOK",

                    "Created", "Interval", "Host", "KeyID",

                    "Fingerprint", "CheckerRunning", "LastEnabled",

                    "ApprovalPending", "ApprovedByDefault",

                    "LastApprovalRequest", "ApprovalDelay",

                    "ApprovalDuration", "Checker", "ExtendedTimeout",

                    "Expires", "LastCheckerStatus")

    def run(self, clients):

        print(self.output(clients))

 

class PropertyCmd(Command):

    """Abstract class for Actions for setting one client property"""

    def run_on_one_client(self, client):

        """Set the Client's D-Bus property"""

        client.Set(client_interface, self.property, self.value_to_set,

                   dbus_interface=dbus.PROPERTIES_IFACE)

 

class ValueArgumentMixIn(object):

    """Mixin class for commands taking a value as argument"""

    def __init__(self, value):

        self.value_to_set = value

 

class MillisecondsValueArgumentMixIn(ValueArgumentMixIn):

    """Mixin class for commands taking a value argument as

    milliseconds."""

    @property

    def value_to_set(self):

        return self._vts

    @value_to_set.setter

    def value_to_set(self, value):

        """When setting, convert value to a datetime.timedelta"""

        self._vts = string_to_delta(value).total_seconds() * 1000

 

# Actual (non-abstract) command classes

 

class PrintTableCmd(PrintCmd):

    def __init__(self, verbose=False):

        self.verbose = verbose

    def output(self, clients):

        if self.verbose:

            keywords = self.all_keywords

        else:

            keywords = ("Name", "Enabled", "Timeout", "LastCheckedOK")

        return str(TableOfClients(clients.values(), keywords))

 

class DumpJSONCmd(PrintCmd):

    def output(self, clients):

        data = {client["Name"]:

                {key: self.dbus_boolean_to_bool(client[key])

                 for key in self.all_keywords}

                for client in clients.values()}

        return json.dumps(data, indent=4, separators=(',', ': '))

    @staticmethod

    def dbus_boolean_to_bool(value):

        if isinstance(value, dbus.Boolean):

            value = bool(value)

        return value

 

class IsEnabledCmd(Command):

    def run_on_one_client(self, client):

        if self.is_enabled(client):

            sys.exit(0)

        sys.exit(1)

    def is_enabled(self, client):

        return client.Get(client_interface, "Enabled",

                          dbus_interface=dbus.PROPERTIES_IFACE)

 

class RemoveCmd(Command):

    def __init__(self, mandos):

        self.mandos = mandos

    def run_on_one_client(self, client):

        self.mandos.RemoveClient(client.__dbus_object_path__)

 

class ApproveCmd(Command):

    def run_on_one_client(self, client):

        client.Approve(dbus.Boolean(True),

                       dbus_interface=client_interface)

 

class DenyCmd(Command):

    def run_on_one_client(self, client):

        client.Approve(dbus.Boolean(False),

                       dbus_interface=client_interface)

 

class EnableCmd(PropertyCmd):

    property = "Enabled"

    value_to_set = dbus.Boolean(True)

 

class DisableCmd(PropertyCmd):

    property = "Enabled"

    value_to_set = dbus.Boolean(False)

 

class BumpTimeoutCmd(PropertyCmd):

    property = "LastCheckedOK"

    value_to_set = ""

 

class StartCheckerCmd(PropertyCmd):

    property = "CheckerRunning"

    value_to_set = dbus.Boolean(True)

 

class StopCheckerCmd(PropertyCmd):

    property = "CheckerRunning"

    value_to_set = dbus.Boolean(False)

 

class ApproveByDefaultCmd(PropertyCmd):

    property = "ApprovedByDefault"

    value_to_set = dbus.Boolean(True)

 

class DenyByDefaultCmd(PropertyCmd):

    property = "ApprovedByDefault"

    value_to_set = dbus.Boolean(False)

 

class SetCheckerCmd(PropertyCmd, ValueArgumentMixIn):

    property = "Checker"

 

class SetHostCmd(PropertyCmd, ValueArgumentMixIn):

    property = "Host"

 

class SetSecretCmd(PropertyCmd, ValueArgumentMixIn):

    property = "Secret"

 

class SetTimeoutCmd(PropertyCmd, MillisecondsValueArgumentMixIn):

    property = "Timeout"

 

class SetExtendedTimeoutCmd(PropertyCmd,

                            MillisecondsValueArgumentMixIn):

    property = "ExtendedTimeout"

 

class SetIntervalCmd(PropertyCmd, MillisecondsValueArgumentMixIn):

    property = "Interval"

 

class SetApprovalDelayCmd(PropertyCmd,

                          MillisecondsValueArgumentMixIn):

    property = "ApprovalDelay"

 

class SetApprovalDurationCmd(PropertyCmd,

                             MillisecondsValueArgumentMixIn):

    property = "ApprovalDuration"

 

                        version="%(prog)s {}".format(version),

    parser.add_argument("-j", "--dump-json", action="store_true",

                        help="Dump client data in JSON format")

    enable_disable = parser.add_mutually_exclusive_group()

    enable_disable.add_argument("-e", "--enable", action="store_true",

                                help="Enable client")

    enable_disable.add_argument("-d", "--disable",

                                action="store_true",

                                help="disable client")

    start_stop_checker = parser.add_mutually_exclusive_group()

    start_stop_checker.add_argument("--start-checker",

                                    action="store_true",

                                    help="Start checker for client")

    start_stop_checker.add_argument("--stop-checker",

                                    action="store_true",

                                    help="Stop checker for client")

    approve_deny_default = parser.add_mutually_exclusive_group()

    approve_deny_default.add_argument(

        "--approve-by-default", action="store_true",

        default=None, dest="approved_by_default",

        help="Set client to be approved by default")

    approve_deny_default.add_argument(

        "--deny-by-default", action="store_false",

        dest="approved_by_default",

        help="Set client to be denied by default")

    parser.add_argument("-s", "--secret",

                        type=argparse.FileType(mode="rb"),

    approve_deny = parser.add_mutually_exclusive_group()

    approve_deny.add_argument(

        "-A", "--approve", action="store_true",

        help="Approve any current client request")

    approve_deny.add_argument("-D", "--deny", action="store_true",

                              help="Deny any current client request")

    parser.add_argument("--check", action="store_true",

                        help="Run self-test")

 

        parser.error("--verbose can only be used alone.")

    if options.dump_json and (options.verbose

                              or has_actions(options)):

        parser.error("--dump-json can only be used alone.")

    if options.is_enabled and len(options.client) > 1:

            parser.error("--is-enabled requires exactly one client")

 

        log.critical("Could not connect to Mandos server")

 

                                 dbus_interface=server_interface)

    mandos_serv_object_manager = dbus.Interface(

        mandos_dbus_objc, dbus_interface=dbus.OBJECT_MANAGER_IFACE)

 

    commands = []

 

    if options.dump_json:

        commands.append(DumpJSONCmd())

 

    if options.enable:

        commands.append(EnableCmd())

 

    if options.disable:

        commands.append(DisableCmd())

 

    if options.bump_timeout:

        commands.append(BumpTimeoutCmd(options.bump_timeout))

 

    if options.start_checker:

        commands.append(StartCheckerCmd())

 

    if options.stop_checker:

        commands.append(StopCheckerCmd())

 

    if options.is_enabled:

        commands.append(IsEnabledCmd())

 

    if options.remove:

        commands.append(RemoveCmd(mandos_serv))

 

    if options.checker is not None:

        commands.append(SetCheckerCmd())

 

    if options.timeout is not None:

        commands.append(SetTimeoutCmd(options.timeout))

 

    if options.extended_timeout:

        commands.append(

            SetExtendedTimeoutCmd(options.extended_timeout))

 

    if options.interval is not None:

        command.append(SetIntervalCmd(options.interval))

 

    if options.approved_by_default is not None:

        if options.approved_by_default:

            command.append(ApproveByDefaultCmd())

        else:

            command.append(DenyByDefaultCmd())

 

    if options.approval_delay is not None:

        command.append(SetApprovalDelayCmd(options.approval_delay))

 

    if options.approval_duration is not None:

        command.append(

            SetApprovalDurationCmd(options.approval_duration))

 

    if options.host is not None:

        command.append(SetHostCmd(options.host))

 

    if options.secret is not None:

        command.append(SetSecretCmd(options.secret))

 

    if options.approve:

        commands.append(ApproveCmd())

 

    if options.deny:

        commands.append(DenyCmd())

 

    # If no command option has been given, show table of clients,

    # optionally verbosely

    if not commands:

        commands.append(PrintTableCmd(verbose=options.verbose))

 

    # block stderr since dbus library prints to stderr

            mandos_clients = {path: ifs_and_props[client_interface]

                              for path, ifs_and_props in

                              mandos_serv_object_manager

                              .GetManagedObjects().items()

                              if client_interface in ifs_and_props}

            # restore stderr

    except dbus.exceptions.DBusException as e:

        log.critical("Failed to access Mandos server through D-Bus:"

                     "\n%s", e)

 

    clients = {}

 

        clients = {bus.get_object(busname, path): properties

                   for path, properties in mandos_clients.items()}

            for path, client in mandos_clients.items():

                log.critical("Client not found on server: %r", name)

 

    # Run all commands on clients

    for command in commands:

        command.run(clients)

 

 

class Test_milliseconds_to_string(unittest.TestCase):

    def test_all(self):

        self.assertEqual(milliseconds_to_string(93785000),

                         "1T02:03:05")

    def test_no_days(self):

        self.assertEqual(milliseconds_to_string(7385000), "02:03:05")

    def test_all_zero(self):

        self.assertEqual(milliseconds_to_string(0), "00:00:00")

    def test_no_fractional_seconds(self):

        self.assertEqual(milliseconds_to_string(400), "00:00:00")

        self.assertEqual(milliseconds_to_string(900), "00:00:00")

        self.assertEqual(milliseconds_to_string(1900), "00:00:01")

 

class Test_string_to_delta(unittest.TestCase):

    def test_handles_basic_rfc3339(self):

        self.assertEqual(string_to_delta("PT2H"),

                         datetime.timedelta(0, 7200))

    def test_falls_back_to_pre_1_6_1_with_warning(self):

        # assertLogs only exists in Python 3.4

        if hasattr(self, "assertLogs"):

            with self.assertLogs(log, logging.WARNING):

                value = string_to_delta("2h")

            value = string_to_delta("2h")

        self.assertEqual(value, datetime.timedelta(0, 7200))

 

class Test_TableOfClients(unittest.TestCase):

    def setUp(self):

        self.tablewords = {

            "Attr1": "X",

            "AttrTwo": "Yy",

            "AttrThree": "Zzz",

            "Bool": "A D-BUS Boolean",

            "NonDbusBoolean": "A Non-D-BUS Boolean",

            "Integer": "An Integer",

            "Timeout": "Timedelta 1",

            "Interval": "Timedelta 2",

            "ApprovalDelay": "Timedelta 3",

            "ApprovalDuration": "Timedelta 4",

            "ExtendedTimeout": "Timedelta 5",

            "String": "A String",

        }

        self.keywords = ["Attr1", "AttrTwo"]

        self.clients = [

            {

                "Attr1": "x1",

                "AttrTwo": "y1",

                "AttrThree": "z1",

                "Bool": dbus.Boolean(False),

                "NonDbusBoolean": False,

                "Integer": 0,

                "Timeout": 0,

                "Interval": 1000,

                "ApprovalDelay": 2000,

                "ApprovalDuration": 3000,

                "ExtendedTimeout": 4000,

                "String": "",

            },

            {

                "Attr1": "x2",

                "AttrTwo": "y2",

                "AttrThree": "z2",

                "Bool": dbus.Boolean(True),

                "NonDbusBoolean": True,

                "Integer": 1,

                "Timeout": 93785000,

                "Interval": 93786000,

                "ApprovalDelay": 93787000,

                "ApprovalDuration": 93788000,

                "ExtendedTimeout": 93789000,

                "String": "A huge string which will not fit," * 10,

            },

        ]

    def test_short_header(self):

        text = str(TableOfClients(self.clients, self.keywords,

                                  self.tablewords))

        expected_text = """

X  Yy

x1 y1

x2 y2

"""[1:-1]

        self.assertEqual(text, expected_text)

    def test_booleans(self):

        keywords = ["Bool", "NonDbusBoolean"]

        text = str(TableOfClients(self.clients, keywords,

                                  self.tablewords))

        expected_text = """

A D-BUS Boolean A Non-D-BUS Boolean

No              False              

Yes             True               

"""[1:-1]

        self.assertEqual(text, expected_text)

    def test_milliseconds_detection(self):

        keywords = ["Integer", "Timeout", "Interval", "ApprovalDelay",

                    "ApprovalDuration", "ExtendedTimeout"]

        text = str(TableOfClients(self.clients, keywords,

                                  self.tablewords))

        expected_text = """

An Integer Timedelta 1 Timedelta 2 Timedelta 3 Timedelta 4 Timedelta 5

0          00:00:00    00:00:01    00:00:02    00:00:03    00:00:04   

1          1T02:03:05  1T02:03:06  1T02:03:07  1T02:03:08  1T02:03:09 

"""[1:-1]

        self.assertEqual(text, expected_text)

    def test_empty_and_long_string_values(self):

        keywords = ["String"]

        text = str(TableOfClients(self.clients, keywords,

                                  self.tablewords))

        expected_text = """

A String                                                                                                                                                                                                                                                                                                                                  

                                                                                                                                                                                                                                                                                                                                          

A huge string which will not fit,A huge string which will not fit,A huge string which will not fit,A huge string which will not fit,A huge string which will not fit,A huge string which will not fit,A huge string which will not fit,A huge string which will not fit,A huge string which will not fit,A huge string which will not fit,

"""[1:-1]

        self.assertEqual(text, expected_text)

 

 

 

def should_only_run_tests():

    parser = argparse.ArgumentParser(add_help=False)

    parser.add_argument("--check", action='store_true')

    args, unknown_args = parser.parse_known_args()

    run_tests = args.check

    if run_tests:

        # Remove --check argument from sys.argv

        sys.argv[1:] = unknown_args

    return run_tests

 

# Add all tests from doctest strings

def load_tests(loader, tests, none):

    import doctest

    tests.addTests(doctest.DocTestSuite())

    return tests

    if should_only_run_tests():

        # Call using ./tdd-python-script --check [--verbose]

        unittest.main()

    else:

        main()