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# Copyright (C) 2017 Jan Jancar
#
# This file is a part of the Mailman PGP plugin.
#
# This program is free software; you can redistribute it and/or modify it under
# the terms of the GNU General Public License as published by the Free
# Software Foundation, either version 3 of the License, or (at your option)
# any later version.
#
# This program is distributed in the hope that it will be useful, but WITHOUT
# ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
# FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for
# more details.
#
# You should have received a copy of the GNU General Public License along with
# this program. If not, see <http://www.gnu.org/licenses/>.
"""Signature checking rule for the pgp-posting-chain."""
from mailman.core.i18n import _
from mailman.interfaces.action import Action
from mailman.interfaces.rules import IRule
from mailman.interfaces.usermanager import IUserManager
from public import public
from zope.component import getUtility
from zope.interface import implementer
from mailman_pgp.database import query
from mailman_pgp.model.address import PGPAddress
from mailman_pgp.model.list import PGPMailingList
from mailman_pgp.pgp.wrapper import PGPWrapper
def record_action(msgdata, action, sender, reason):
msgdata['moderation_action'] = action
msgdata['moderation_sender'] = sender
msgdata.setdefault('moderation_reasons', []).append(reason)
@public
@implementer(IRule)
class Signature:
"""The signature checking rule."""
name = 'signature'
description = _(
"A rule which enforces PGP enabled list signature configuration.")
record = True
def check(self, mlist, msg, msgdata):
"""See `IRule`."""
# Find the `PGPMailingList` this is for.
enc_list = query(PGPMailingList).filter_by(
list_id=mlist.list_id).first()
if enc_list is None:
raise ValueError('PGP enabled mailing list not found.')
# Wrap the message to work with it.
wrapped = PGPWrapper(msg)
# Take unsigned_msg_action if unsigned.
if not wrapped.is_signed():
action = enc_list.unsigned_msg_action
if action != Action.defer:
record_action(msgdata, action, msg.sender,
'The message is unsigned.')
return True
# Take `inline_pgp_action` if inline signed.
if wrapped.inline.is_signed():
action = enc_list.inline_pgp_action
if action != Action.defer:
record_action(msgdata, action, msg.sender,
'Inline PGP is not allowed.')
return True
# Lookup the address by sender, and its corresponding `PGPAddress`.
user_manager = getUtility(IUserManager)
sender = msg.sender
address = user_manager.get_address(sender)
enc_address = PGPAddress.query().filter_by(
email=address.email).first()
if enc_address is None:
raise ValueError('PGP enabled address not found.')
# See if we have a key.
key = enc_address.key
if key is None:
raise ValueError('No key?')
# Take the `invalid_sig_action` if the verification failed.
if not wrapped.verifies(key):
action = enc_list.invalid_sig_action
if action != Action.defer:
record_action(msgdata, action, msg.sender,
'Signature did not verify.')
return True
# # TODO: handle more signatures here?
# sig_obj = next(verification.good_signatures)
# sig_key = sig_obj.by
# sig_sig = sig_obj.signature
#
# # Take the `expired_sig_action` if either he signature or the key
# # is expired.
# if sig_sig.is_expired or sig_key.is_expired:
# action = enc_list.expired_sig_action
# if action is not None:
# _record_action(msgdata, action, msg.sender,
# 'Signature or key expired.')
# return True
# XXX: we need to track key revocation separately to use it here
# TODO: check key revocation here
return False
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