summary refs log tree commit diff
path: root/synapse/events/spamcheck.py
blob: a23b6b7b6137b6d4b6af1be1e1103885a19ba573 (plain) (blame)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
# -*- coding: utf-8 -*-
# Copyright 2017 New Vector Ltd
# Copyright 2019 The Matrix.org Foundation C.I.C.
#
# Licensed under the Apache License, Version 2.0 (the "License");
# you may not use this file except in compliance with the License.
# You may obtain a copy of the License at
#
#     http://www.apache.org/licenses/LICENSE-2.0
#
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS,
# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
# See the License for the specific language governing permissions and
# limitations under the License.

import inspect
from typing import Dict

from synapse.spam_checker_api import SpamCheckerApi

MYPY = False
if MYPY:
    import synapse.server


class SpamChecker(object):
    def __init__(self, hs: "synapse.server.HomeServer"):
        self.spam_checker = None

        module = None
        config = None
        try:
            module, config = hs.config.spam_checker
        except Exception:
            pass

        if module is not None:
            # Older spam checkers don't accept the `api` argument, so we
            # try and detect support.
            spam_args = inspect.getfullargspec(module)
            if "api" in spam_args.args:
                api = SpamCheckerApi(hs)
                self.spam_checker = module(config=config, api=api)
            else:
                self.spam_checker = module(config=config)

    def check_event_for_spam(self, event: "synapse.events.EventBase") -> bool:
        """Checks if a given event is considered "spammy" by this server.

        If the server considers an event spammy, then it will be rejected if
        sent by a local user. If it is sent by a user on another server, then
        users receive a blank event.

        Args:
            event: the event to be checked

        Returns:
            True if the event is spammy.
        """
        if self.spam_checker is None:
            return False

        return self.spam_checker.check_event_for_spam(event)

    def user_may_invite(
        self, inviter_userid: str, invitee_userid: str, room_id: str
    ) -> bool:
        """Checks if a given user may send an invite

        If this method returns false, the invite will be rejected.

        Args:
            inviter_userid: The user ID of the sender of the invitation
            invitee_userid: The user ID targeted in the invitation
            room_id: The room ID

        Returns:
            True if the user may send an invite, otherwise False
        """
        if self.spam_checker is None:
            return True

        return self.spam_checker.user_may_invite(
            inviter_userid, invitee_userid, room_id
        )

    def user_may_create_room(self, userid: str) -> bool:
        """Checks if a given user may create a room

        If this method returns false, the creation request will be rejected.

        Args:
            userid: The ID of the user attempting to create a room

        Returns:
            True if the user may create a room, otherwise False
        """
        if self.spam_checker is None:
            return True

        return self.spam_checker.user_may_create_room(userid)

    def user_may_create_room_alias(self, userid: str, room_alias: str) -> bool:
        """Checks if a given user may create a room alias

        If this method returns false, the association request will be rejected.

        Args:
            userid: The ID of the user attempting to create a room alias
            room_alias: The alias to be created

        Returns:
            True if the user may create a room alias, otherwise False
        """
        if self.spam_checker is None:
            return True

        return self.spam_checker.user_may_create_room_alias(userid, room_alias)

    def user_may_publish_room(self, userid: str, room_id: str) -> bool:
        """Checks if a given user may publish a room to the directory

        If this method returns false, the publish request will be rejected.

        Args:
            userid: The user ID attempting to publish the room
            room_id: The ID of the room that would be published

        Returns:
            True if the user may publish the room, otherwise False
        """
        if self.spam_checker is None:
            return True

        return self.spam_checker.user_may_publish_room(userid, room_id)

    def check_username_for_spam(self, user_profile: Dict[str, str]) -> bool:
        """Checks if a user ID or display name are considered "spammy" by this server.

        If the server considers a username spammy, then it will not be included in
        user directory results.

        Args:
            user_profile: The user information to check, it contains the keys:
                * user_id
                * display_name
                * avatar_url

        Returns:
            True if the user is spammy.
        """
        if self.spam_checker is None:
            return False

        # For backwards compatibility, if the method does not exist on the spam checker, fallback to not interfering.
        checker = getattr(self.spam_checker, "check_username_for_spam", None)
        if not checker:
            return False
        # Make a copy of the user profile object to ensure the spam checker
        # cannot modify it.
        return checker(user_profile.copy())