forked-synapse/synapse/handlers/room_member.py

802 lines
29 KiB
Python

# -*- coding: utf-8 -*-
# Copyright 2016 OpenMarket Ltd
#
# 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 logging
from signedjson.key import decode_verify_key_bytes
from signedjson.sign import verify_signed_json
from twisted.internet import defer
from unpaddedbase64 import decode_base64
import synapse.types
from synapse.api.constants import (
EventTypes, Membership,
)
from synapse.api.errors import AuthError, SynapseError, Codes
from synapse.types import UserID, RoomID
from synapse.util.async import Linearizer
from synapse.util.distributor import user_left_room, user_joined_room
from ._base import BaseHandler
logger = logging.getLogger(__name__)
id_server_scheme = "https://"
class RoomMemberHandler(BaseHandler):
# TODO(paul): This handler currently contains a messy conflation of
# low-level API that works on UserID objects and so on, and REST-level
# API that takes ID strings and returns pagination chunks. These concerns
# ought to be separated out a lot better.
def __init__(self, hs):
super(RoomMemberHandler, self).__init__(hs)
self.member_linearizer = Linearizer(name="member")
self.clock = hs.get_clock()
self.spam_checker = hs.get_spam_checker()
self.distributor = hs.get_distributor()
self.distributor.declare("user_joined_room")
self.distributor.declare("user_left_room")
@defer.inlineCallbacks
def _local_membership_update(
self, requester, target, room_id, membership,
prev_event_ids,
txn_id=None,
ratelimit=True,
content=None,
):
if content is None:
content = {}
msg_handler = self.hs.get_handlers().message_handler
content["membership"] = membership
if requester.is_guest:
content["kind"] = "guest"
event, context = yield msg_handler.create_event(
requester,
{
"type": EventTypes.Member,
"content": content,
"room_id": room_id,
"sender": requester.user.to_string(),
"state_key": target.to_string(),
# For backwards compatibility:
"membership": membership,
},
token_id=requester.access_token_id,
txn_id=txn_id,
prev_event_ids=prev_event_ids,
)
# Check if this event matches the previous membership event for the user.
duplicate = yield msg_handler.deduplicate_state_event(event, context)
if duplicate is not None:
# Discard the new event since this membership change is a no-op.
defer.returnValue(duplicate)
yield msg_handler.handle_new_client_event(
requester,
event,
context,
extra_users=[target],
ratelimit=ratelimit,
)
prev_member_event_id = context.prev_state_ids.get(
(EventTypes.Member, target.to_string()),
None
)
if event.membership == Membership.JOIN:
# Only fire user_joined_room if the user has acutally joined the
# room. Don't bother if the user is just changing their profile
# info.
newly_joined = True
if prev_member_event_id:
prev_member_event = yield self.store.get_event(prev_member_event_id)
newly_joined = prev_member_event.membership != Membership.JOIN
if newly_joined:
yield user_joined_room(self.distributor, target, room_id)
elif event.membership == Membership.LEAVE:
if prev_member_event_id:
prev_member_event = yield self.store.get_event(prev_member_event_id)
if prev_member_event.membership == Membership.JOIN:
user_left_room(self.distributor, target, room_id)
defer.returnValue(event)
@defer.inlineCallbacks
def remote_join(self, remote_room_hosts, room_id, user, content):
if len(remote_room_hosts) == 0:
raise SynapseError(404, "No known servers")
# We don't do an auth check if we are doing an invite
# join dance for now, since we're kinda implicitly checking
# that we are allowed to join when we decide whether or not we
# need to do the invite/join dance.
yield self.hs.get_handlers().federation_handler.do_invite_join(
remote_room_hosts,
room_id,
user.to_string(),
content,
)
yield user_joined_room(self.distributor, user, room_id)
@defer.inlineCallbacks
def update_membership(
self,
requester,
target,
room_id,
action,
txn_id=None,
remote_room_hosts=None,
third_party_signed=None,
ratelimit=True,
content=None,
):
key = (room_id,)
with (yield self.member_linearizer.queue(key)):
result = yield self._update_membership(
requester,
target,
room_id,
action,
txn_id=txn_id,
remote_room_hosts=remote_room_hosts,
third_party_signed=third_party_signed,
ratelimit=ratelimit,
content=content,
)
defer.returnValue(result)
@defer.inlineCallbacks
def _update_membership(
self,
requester,
target,
room_id,
action,
txn_id=None,
remote_room_hosts=None,
third_party_signed=None,
ratelimit=True,
content=None,
):
content_specified = bool(content)
if content is None:
content = {}
effective_membership_state = action
if action in ["kick", "unban"]:
effective_membership_state = "leave"
# if this is a join with a 3pid signature, we may need to turn a 3pid
# invite into a normal invite before we can handle the join.
if third_party_signed is not None:
replication = self.hs.get_replication_layer()
yield replication.exchange_third_party_invite(
third_party_signed["sender"],
target.to_string(),
room_id,
third_party_signed,
)
if not remote_room_hosts:
remote_room_hosts = []
if effective_membership_state not in ("leave", "ban",):
is_blocked = yield self.store.is_room_blocked(room_id)
if is_blocked:
raise SynapseError(403, "This room has been blocked on this server")
if effective_membership_state == "invite":
block_invite = False
is_requester_admin = yield self.auth.is_server_admin(
requester.user,
)
if not is_requester_admin:
if self.hs.config.block_non_admin_invites:
logger.info(
"Blocking invite: user is not admin and non-admin "
"invites disabled"
)
block_invite = True
if not self.spam_checker.user_may_invite(
requester.user.to_string(), target.to_string(), room_id,
):
logger.info("Blocking invite due to spam checker")
block_invite = True
if block_invite:
raise SynapseError(
403, "Invites have been disabled on this server",
)
latest_event_ids = yield self.store.get_latest_event_ids_in_room(room_id)
current_state_ids = yield self.state_handler.get_current_state_ids(
room_id, latest_event_ids=latest_event_ids,
)
old_state_id = current_state_ids.get((EventTypes.Member, target.to_string()))
if old_state_id:
old_state = yield self.store.get_event(old_state_id, allow_none=True)
old_membership = old_state.content.get("membership") if old_state else None
if action == "unban" and old_membership != "ban":
raise SynapseError(
403,
"Cannot unban user who was not banned"
" (membership=%s)" % old_membership,
errcode=Codes.BAD_STATE
)
if old_membership == "ban" and action != "unban":
raise SynapseError(
403,
"Cannot %s user who was banned" % (action,),
errcode=Codes.BAD_STATE
)
if old_state:
same_content = content == old_state.content
same_membership = old_membership == effective_membership_state
same_sender = requester.user.to_string() == old_state.sender
if same_sender and same_membership and same_content:
defer.returnValue(old_state)
is_host_in_room = yield self._is_host_in_room(current_state_ids)
if effective_membership_state == Membership.JOIN:
if requester.is_guest:
guest_can_join = yield self._can_guest_join(current_state_ids)
if not guest_can_join:
# This should be an auth check, but guests are a local concept,
# so don't really fit into the general auth process.
raise AuthError(403, "Guest access not allowed")
if not is_host_in_room:
inviter = yield self.get_inviter(target.to_string(), room_id)
if inviter and not self.hs.is_mine(inviter):
remote_room_hosts.append(inviter.domain)
content["membership"] = Membership.JOIN
profile = self.hs.get_handlers().profile_handler
if not content_specified:
content["displayname"] = yield profile.get_displayname(target)
content["avatar_url"] = yield profile.get_avatar_url(target)
if requester.is_guest:
content["kind"] = "guest"
ret = yield self.remote_join(
remote_room_hosts, room_id, target, content
)
defer.returnValue(ret)
elif effective_membership_state == Membership.LEAVE:
if not is_host_in_room:
# perhaps we've been invited
inviter = yield self.get_inviter(target.to_string(), room_id)
if not inviter:
raise SynapseError(404, "Not a known room")
if self.hs.is_mine(inviter):
# the inviter was on our server, but has now left. Carry on
# with the normal rejection codepath.
#
# This is a bit of a hack, because the room might still be
# active on other servers.
pass
else:
# send the rejection to the inviter's HS.
remote_room_hosts = remote_room_hosts + [inviter.domain]
fed_handler = self.hs.get_handlers().federation_handler
try:
ret = yield fed_handler.do_remotely_reject_invite(
remote_room_hosts,
room_id,
target.to_string(),
)
defer.returnValue(ret)
except Exception as e:
# if we were unable to reject the exception, just mark
# it as rejected on our end and plough ahead.
#
# The 'except' clause is very broad, but we need to
# capture everything from DNS failures upwards
#
logger.warn("Failed to reject invite: %s", e)
yield self.store.locally_reject_invite(
target.to_string(), room_id
)
defer.returnValue({})
res = yield self._local_membership_update(
requester=requester,
target=target,
room_id=room_id,
membership=effective_membership_state,
txn_id=txn_id,
ratelimit=ratelimit,
prev_event_ids=latest_event_ids,
content=content,
)
defer.returnValue(res)
@defer.inlineCallbacks
def send_membership_event(
self,
requester,
event,
context,
remote_room_hosts=None,
ratelimit=True,
):
"""
Change the membership status of a user in a room.
Args:
requester (Requester): The local user who requested the membership
event. If None, certain checks, like whether this homeserver can
act as the sender, will be skipped.
event (SynapseEvent): The membership event.
context: The context of the event.
is_guest (bool): Whether the sender is a guest.
room_hosts ([str]): Homeservers which are likely to already be in
the room, and could be danced with in order to join this
homeserver for the first time.
ratelimit (bool): Whether to rate limit this request.
Raises:
SynapseError if there was a problem changing the membership.
"""
remote_room_hosts = remote_room_hosts or []
target_user = UserID.from_string(event.state_key)
room_id = event.room_id
if requester is not None:
sender = UserID.from_string(event.sender)
assert sender == requester.user, (
"Sender (%s) must be same as requester (%s)" %
(sender, requester.user)
)
assert self.hs.is_mine(sender), "Sender must be our own: %s" % (sender,)
else:
requester = synapse.types.create_requester(target_user)
message_handler = self.hs.get_handlers().message_handler
prev_event = yield message_handler.deduplicate_state_event(event, context)
if prev_event is not None:
return
if event.membership == Membership.JOIN:
if requester.is_guest:
guest_can_join = yield self._can_guest_join(context.prev_state_ids)
if not guest_can_join:
# This should be an auth check, but guests are a local concept,
# so don't really fit into the general auth process.
raise AuthError(403, "Guest access not allowed")
if event.membership not in (Membership.LEAVE, Membership.BAN):
is_blocked = yield self.store.is_room_blocked(room_id)
if is_blocked:
raise SynapseError(403, "This room has been blocked on this server")
yield message_handler.handle_new_client_event(
requester,
event,
context,
extra_users=[target_user],
ratelimit=ratelimit,
)
prev_member_event_id = context.prev_state_ids.get(
(EventTypes.Member, event.state_key),
None
)
if event.membership == Membership.JOIN:
# Only fire user_joined_room if the user has acutally joined the
# room. Don't bother if the user is just changing their profile
# info.
newly_joined = True
if prev_member_event_id:
prev_member_event = yield self.store.get_event(prev_member_event_id)
newly_joined = prev_member_event.membership != Membership.JOIN
if newly_joined:
yield user_joined_room(self.distributor, target_user, room_id)
elif event.membership == Membership.LEAVE:
if prev_member_event_id:
prev_member_event = yield self.store.get_event(prev_member_event_id)
if prev_member_event.membership == Membership.JOIN:
user_left_room(self.distributor, target_user, room_id)
@defer.inlineCallbacks
def _can_guest_join(self, current_state_ids):
"""
Returns whether a guest can join a room based on its current state.
"""
guest_access_id = current_state_ids.get((EventTypes.GuestAccess, ""), None)
if not guest_access_id:
defer.returnValue(False)
guest_access = yield self.store.get_event(guest_access_id)
defer.returnValue(
guest_access
and guest_access.content
and "guest_access" in guest_access.content
and guest_access.content["guest_access"] == "can_join"
)
@defer.inlineCallbacks
def lookup_room_alias(self, room_alias):
"""
Get the room ID associated with a room alias.
Args:
room_alias (RoomAlias): The alias to look up.
Returns:
A tuple of:
The room ID as a RoomID object.
Hosts likely to be participating in the room ([str]).
Raises:
SynapseError if room alias could not be found.
"""
directory_handler = self.hs.get_handlers().directory_handler
mapping = yield directory_handler.get_association(room_alias)
if not mapping:
raise SynapseError(404, "No such room alias")
room_id = mapping["room_id"]
servers = mapping["servers"]
defer.returnValue((RoomID.from_string(room_id), servers))
@defer.inlineCallbacks
def get_inviter(self, user_id, room_id):
invite = yield self.store.get_invite_for_user_in_room(
user_id=user_id,
room_id=room_id,
)
if invite:
defer.returnValue(UserID.from_string(invite.sender))
@defer.inlineCallbacks
def do_3pid_invite(
self,
room_id,
inviter,
medium,
address,
id_server,
requester,
txn_id
):
if self.hs.config.block_non_admin_invites:
is_requester_admin = yield self.auth.is_server_admin(
requester.user,
)
if not is_requester_admin:
raise SynapseError(
403, "Invites have been disabled on this server",
Codes.FORBIDDEN,
)
invitee = yield self._lookup_3pid(
id_server, medium, address
)
if invitee:
yield self.update_membership(
requester,
UserID.from_string(invitee),
room_id,
"invite",
txn_id=txn_id,
)
else:
yield self._make_and_store_3pid_invite(
requester,
id_server,
medium,
address,
room_id,
inviter,
txn_id=txn_id
)
@defer.inlineCallbacks
def _lookup_3pid(self, id_server, medium, address):
"""Looks up a 3pid in the passed identity server.
Args:
id_server (str): The server name (including port, if required)
of the identity server to use.
medium (str): The type of the third party identifier (e.g. "email").
address (str): The third party identifier (e.g. "foo@example.com").
Returns:
str: the matrix ID of the 3pid, or None if it is not recognized.
"""
try:
data = yield self.hs.get_simple_http_client().get_json(
"%s%s/_matrix/identity/api/v1/lookup" % (id_server_scheme, id_server,),
{
"medium": medium,
"address": address,
}
)
if "mxid" in data:
if "signatures" not in data:
raise AuthError(401, "No signatures on 3pid binding")
self.verify_any_signature(data, id_server)
defer.returnValue(data["mxid"])
except IOError as e:
logger.warn("Error from identity server lookup: %s" % (e,))
defer.returnValue(None)
@defer.inlineCallbacks
def verify_any_signature(self, data, server_hostname):
if server_hostname not in data["signatures"]:
raise AuthError(401, "No signature from server %s" % (server_hostname,))
for key_name, signature in data["signatures"][server_hostname].items():
key_data = yield self.hs.get_simple_http_client().get_json(
"%s%s/_matrix/identity/api/v1/pubkey/%s" %
(id_server_scheme, server_hostname, key_name,),
)
if "public_key" not in key_data:
raise AuthError(401, "No public key named %s from %s" %
(key_name, server_hostname,))
verify_signed_json(
data,
server_hostname,
decode_verify_key_bytes(key_name, decode_base64(key_data["public_key"]))
)
return
@defer.inlineCallbacks
def _make_and_store_3pid_invite(
self,
requester,
id_server,
medium,
address,
room_id,
user,
txn_id
):
room_state = yield self.hs.get_state_handler().get_current_state(room_id)
inviter_display_name = ""
inviter_avatar_url = ""
member_event = room_state.get((EventTypes.Member, user.to_string()))
if member_event:
inviter_display_name = member_event.content.get("displayname", "")
inviter_avatar_url = member_event.content.get("avatar_url", "")
canonical_room_alias = ""
canonical_alias_event = room_state.get((EventTypes.CanonicalAlias, ""))
if canonical_alias_event:
canonical_room_alias = canonical_alias_event.content.get("alias", "")
room_name = ""
room_name_event = room_state.get((EventTypes.Name, ""))
if room_name_event:
room_name = room_name_event.content.get("name", "")
room_join_rules = ""
join_rules_event = room_state.get((EventTypes.JoinRules, ""))
if join_rules_event:
room_join_rules = join_rules_event.content.get("join_rule", "")
room_avatar_url = ""
room_avatar_event = room_state.get((EventTypes.RoomAvatar, ""))
if room_avatar_event:
room_avatar_url = room_avatar_event.content.get("url", "")
token, public_keys, fallback_public_key, display_name = (
yield self._ask_id_server_for_third_party_invite(
id_server=id_server,
medium=medium,
address=address,
room_id=room_id,
inviter_user_id=user.to_string(),
room_alias=canonical_room_alias,
room_avatar_url=room_avatar_url,
room_join_rules=room_join_rules,
room_name=room_name,
inviter_display_name=inviter_display_name,
inviter_avatar_url=inviter_avatar_url
)
)
msg_handler = self.hs.get_handlers().message_handler
yield msg_handler.create_and_send_nonmember_event(
requester,
{
"type": EventTypes.ThirdPartyInvite,
"content": {
"display_name": display_name,
"public_keys": public_keys,
# For backwards compatibility:
"key_validity_url": fallback_public_key["key_validity_url"],
"public_key": fallback_public_key["public_key"],
},
"room_id": room_id,
"sender": user.to_string(),
"state_key": token,
},
txn_id=txn_id,
)
@defer.inlineCallbacks
def _ask_id_server_for_third_party_invite(
self,
id_server,
medium,
address,
room_id,
inviter_user_id,
room_alias,
room_avatar_url,
room_join_rules,
room_name,
inviter_display_name,
inviter_avatar_url
):
"""
Asks an identity server for a third party invite.
Args:
id_server (str): hostname + optional port for the identity server.
medium (str): The literal string "email".
address (str): The third party address being invited.
room_id (str): The ID of the room to which the user is invited.
inviter_user_id (str): The user ID of the inviter.
room_alias (str): An alias for the room, for cosmetic notifications.
room_avatar_url (str): The URL of the room's avatar, for cosmetic
notifications.
room_join_rules (str): The join rules of the email (e.g. "public").
room_name (str): The m.room.name of the room.
inviter_display_name (str): The current display name of the
inviter.
inviter_avatar_url (str): The URL of the inviter's avatar.
Returns:
A deferred tuple containing:
token (str): The token which must be signed to prove authenticity.
public_keys ([{"public_key": str, "key_validity_url": str}]):
public_key is a base64-encoded ed25519 public key.
fallback_public_key: One element from public_keys.
display_name (str): A user-friendly name to represent the invited
user.
"""
is_url = "%s%s/_matrix/identity/api/v1/store-invite" % (
id_server_scheme, id_server,
)
invite_config = {
"medium": medium,
"address": address,
"room_id": room_id,
"room_alias": room_alias,
"room_avatar_url": room_avatar_url,
"room_join_rules": room_join_rules,
"room_name": room_name,
"sender": inviter_user_id,
"sender_display_name": inviter_display_name,
"sender_avatar_url": inviter_avatar_url,
}
if self.hs.config.invite_3pid_guest:
registration_handler = self.hs.get_handlers().registration_handler
guest_access_token = yield registration_handler.guest_access_token_for(
medium=medium,
address=address,
inviter_user_id=inviter_user_id,
)
guest_user_info = yield self.hs.get_auth().get_user_by_access_token(
guest_access_token
)
invite_config.update({
"guest_access_token": guest_access_token,
"guest_user_id": guest_user_info["user"].to_string(),
})
data = yield self.hs.get_simple_http_client().post_urlencoded_get_json(
is_url,
invite_config
)
# TODO: Check for success
token = data["token"]
public_keys = data.get("public_keys", [])
if "public_key" in data:
fallback_public_key = {
"public_key": data["public_key"],
"key_validity_url": "%s%s/_matrix/identity/api/v1/pubkey/isvalid" % (
id_server_scheme, id_server,
),
}
else:
fallback_public_key = public_keys[0]
if not public_keys:
public_keys.append(fallback_public_key)
display_name = data["display_name"]
defer.returnValue((token, public_keys, fallback_public_key, display_name))
@defer.inlineCallbacks
def forget(self, user, room_id):
user_id = user.to_string()
member = yield self.state_handler.get_current_state(
room_id=room_id,
event_type=EventTypes.Member,
state_key=user_id
)
membership = member.membership if member else None
if membership is not None and membership not in [
Membership.LEAVE, Membership.BAN
]:
raise SynapseError(400, "User %s in room %s" % (
user_id, room_id
))
if membership:
yield self.store.forget(user_id, room_id)
@defer.inlineCallbacks
def _is_host_in_room(self, current_state_ids):
# Have we just created the room, and is this about to be the very
# first member event?
create_event_id = current_state_ids.get(("m.room.create", ""))
if len(current_state_ids) == 1 and create_event_id:
defer.returnValue(self.hs.is_mine_id(create_event_id))
for etype, state_key in current_state_ids:
if etype != EventTypes.Member or not self.hs.is_mine_id(state_key):
continue
event_id = current_state_ids[(etype, state_key)]
event = yield self.store.get_event(event_id, allow_none=True)
if not event:
continue
if event.membership == Membership.JOIN:
defer.returnValue(True)
defer.returnValue(False)