189 lines
		
	
	
		
			6.9 KiB
		
	
	
	
		
			Python
		
	
	
			
		
		
	
	
			189 lines
		
	
	
		
			6.9 KiB
		
	
	
	
		
			Python
		
	
	
| # -*- coding: utf-8 -*-
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| # Copyright 2014-2016 OpenMarket Ltd
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| #
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| # Licensed under the Apache License, Version 2.0 (the "License");
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| # you may not use this file except in compliance with the License.
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| # You may obtain a copy of the License at
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| #
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| #     http://www.apache.org/licenses/LICENSE-2.0
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| #
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| # Unless required by applicable law or agreed to in writing, software
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| # distributed under the License is distributed on an "AS IS" BASIS,
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| # WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
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| # See the License for the specific language governing permissions and
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| # limitations under the License.
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| 
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| from typing import Union
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| 
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| from synapse.api.constants import MAX_ALIAS_LENGTH, EventTypes, Membership
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| from synapse.api.errors import Codes, SynapseError
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| from synapse.api.room_versions import EventFormatVersions
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| from synapse.config.homeserver import HomeServerConfig
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| from synapse.events import EventBase
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| from synapse.events.builder import EventBuilder
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| from synapse.events.utils import validate_canonicaljson
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| from synapse.federation.federation_server import server_matches_acl_event
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| from synapse.types import EventID, RoomID, UserID
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| 
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| 
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| class EventValidator:
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|     def validate_new(self, event: EventBase, config: HomeServerConfig):
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|         """Validates the event has roughly the right format
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| 
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|         Args:
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|             event: The event to validate.
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|             config: The homeserver's configuration.
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|         """
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|         self.validate_builder(event)
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| 
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|         if event.format_version == EventFormatVersions.V1:
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|             EventID.from_string(event.event_id)
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| 
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|         required = [
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|             "auth_events",
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|             "content",
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|             "hashes",
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|             "origin",
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|             "prev_events",
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|             "sender",
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|             "type",
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|         ]
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| 
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|         for k in required:
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|             if not hasattr(event, k):
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|                 raise SynapseError(400, "Event does not have key %s" % (k,))
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| 
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|         # Check that the following keys have string values
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|         event_strings = ["origin"]
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| 
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|         for s in event_strings:
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|             if not isinstance(getattr(event, s), str):
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|                 raise SynapseError(400, "'%s' not a string type" % (s,))
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| 
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|         # Depending on the room version, ensure the data is spec compliant JSON.
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|         if event.room_version.strict_canonicaljson:
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|             # Note that only the client controlled portion of the event is
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|             # checked, since we trust the portions of the event we created.
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|             validate_canonicaljson(event.content)
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| 
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|         if event.type == EventTypes.Aliases:
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|             if "aliases" in event.content:
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|                 for alias in event.content["aliases"]:
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|                     if len(alias) > MAX_ALIAS_LENGTH:
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|                         raise SynapseError(
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|                             400,
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|                             (
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|                                 "Can't create aliases longer than"
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|                                 " %d characters" % (MAX_ALIAS_LENGTH,)
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|                             ),
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|                             Codes.INVALID_PARAM,
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|                         )
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| 
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|         if event.type == EventTypes.Retention:
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|             self._validate_retention(event)
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| 
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|         if event.type == EventTypes.ServerACL:
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|             if not server_matches_acl_event(config.server_name, event):
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|                 raise SynapseError(
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|                     400, "Can't create an ACL event that denies the local server"
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|                 )
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| 
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|     def _validate_retention(self, event: EventBase):
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|         """Checks that an event that defines the retention policy for a room respects the
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|         format enforced by the spec.
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| 
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|         Args:
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|             event: The event to validate.
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|         """
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|         if not event.is_state():
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|             raise SynapseError(code=400, msg="must be a state event")
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| 
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|         min_lifetime = event.content.get("min_lifetime")
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|         max_lifetime = event.content.get("max_lifetime")
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| 
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|         if min_lifetime is not None:
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|             if not isinstance(min_lifetime, int):
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|                 raise SynapseError(
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|                     code=400,
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|                     msg="'min_lifetime' must be an integer",
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|                     errcode=Codes.BAD_JSON,
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|                 )
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| 
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|         if max_lifetime is not None:
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|             if not isinstance(max_lifetime, int):
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|                 raise SynapseError(
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|                     code=400,
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|                     msg="'max_lifetime' must be an integer",
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|                     errcode=Codes.BAD_JSON,
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|                 )
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| 
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|         if (
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|             min_lifetime is not None
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|             and max_lifetime is not None
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|             and min_lifetime > max_lifetime
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|         ):
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|             raise SynapseError(
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|                 code=400,
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|                 msg="'min_lifetime' can't be greater than 'max_lifetime",
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|                 errcode=Codes.BAD_JSON,
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|             )
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| 
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|     def validate_builder(self, event: Union[EventBase, EventBuilder]):
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|         """Validates that the builder/event has roughly the right format. Only
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|         checks values that we expect a proto event to have, rather than all the
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|         fields an event would have
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|         """
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| 
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|         strings = ["room_id", "sender", "type"]
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| 
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|         if hasattr(event, "state_key"):
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|             strings.append("state_key")
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| 
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|         for s in strings:
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|             if not isinstance(getattr(event, s), str):
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|                 raise SynapseError(400, "Not '%s' a string type" % (s,))
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| 
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|         RoomID.from_string(event.room_id)
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|         UserID.from_string(event.sender)
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| 
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|         if event.type == EventTypes.Message:
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|             strings = ["body", "msgtype"]
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| 
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|             self._ensure_strings(event.content, strings)
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| 
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|         elif event.type == EventTypes.Topic:
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|             self._ensure_strings(event.content, ["topic"])
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|             self._ensure_state_event(event)
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|         elif event.type == EventTypes.Name:
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|             self._ensure_strings(event.content, ["name"])
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|             self._ensure_state_event(event)
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|         elif event.type == EventTypes.Member:
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|             if "membership" not in event.content:
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|                 raise SynapseError(400, "Content has not membership key")
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| 
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|             if event.content["membership"] not in Membership.LIST:
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|                 raise SynapseError(400, "Invalid membership key")
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| 
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|             self._ensure_state_event(event)
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|         elif event.type == EventTypes.Tombstone:
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|             if "replacement_room" not in event.content:
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|                 raise SynapseError(400, "Content has no replacement_room key")
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| 
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|             if event.content["replacement_room"] == event.room_id:
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|                 raise SynapseError(
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|                     400, "Tombstone cannot reference the room it was sent in"
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|                 )
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| 
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|             self._ensure_state_event(event)
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| 
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|     def _ensure_strings(self, d, keys):
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|         for s in keys:
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|             if s not in d:
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|                 raise SynapseError(400, "'%s' not in content" % (s,))
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|             if not isinstance(d[s], str):
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|                 raise SynapseError(400, "'%s' not a string type" % (s,))
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| 
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|     def _ensure_state_event(self, event):
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|         if not event.is_state():
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|             raise SynapseError(400, "'%s' must be state events" % (event.type,))
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