Merge branch 'develop' into babolivier/mark_unread

1 files changed, 107 insertions, 57 deletions

diff --git a/synapse/event_auth.py b/synapse/event_auth.py
index 4e91df60e6..c582355146 100644
--- a/synapse/event_auth.py
+++ b/synapse/event_auth.py
@@ -1,5 +1,6 @@
 # -*- coding: utf-8 -*-
 # Copyright 2014 - 2016 OpenMarket Ltd
+# Copyright 2020 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.
@@ -14,6 +15,7 @@
 # limitations under the License.
 
 import logging
+from typing import List, Optional, Set, Tuple
 
 from canonicaljson import encode_canonical_json
 from signedjson.key import decode_verify_key_bytes
@@ -22,17 +24,28 @@ from unpaddedbase64 import decode_base64
 
 from synapse.api.constants import EventTypes, JoinRules, Membership
 from synapse.api.errors import AuthError, EventSizeError, SynapseError
-from synapse.api.room_versions import KNOWN_ROOM_VERSIONS, EventFormatVersions
-from synapse.types import UserID, get_domain_from_id
+from synapse.api.room_versions import (
+    KNOWN_ROOM_VERSIONS,
+    EventFormatVersions,
+    RoomVersion,
+)
+from synapse.events import EventBase
+from synapse.types import StateMap, UserID, get_domain_from_id
 
 logger = logging.getLogger(__name__)
 
 
-def check(room_version, event, auth_events, do_sig_check=True, do_size_check=True):
+def check(
+    room_version_obj: RoomVersion,
+    event: EventBase,
+    auth_events: StateMap[EventBase],
+    do_sig_check: bool = True,
+    do_size_check: bool = True,
+) -> None:
     """ Checks if this event is correctly authed.
 
     Args:
-        room_version (str): the version of the room
+        room_version_obj: the version of the room
         event: the event being checked.
         auth_events (dict: event-key -> event): the existing room state.
 
@@ -42,12 +55,26 @@ def check(room_version, event, auth_events, do_sig_check=True, do_size_check=Tru
     Returns:
          if the auth checks pass.
     """
+    assert isinstance(auth_events, dict)
+
     if do_size_check:
         _check_size_limits(event)
 
     if not hasattr(event, "room_id"):
         raise AuthError(500, "Event has no room_id: %s" % event)
 
+    room_id = event.room_id
+
+    # I'm not really expecting to get auth events in the wrong room, but let's
+    # sanity-check it
+    for auth_event in auth_events.values():
+        if auth_event.room_id != room_id:
+            raise Exception(
+                "During auth for event %s in room %s, found event %s in the state "
+                "which is in room %s"
+                % (event.event_id, room_id, auth_event.event_id, auth_event.room_id)
+            )
+
     if do_sig_check:
         sender_domain = get_domain_from_id(event.sender)
 
@@ -74,13 +101,12 @@ def check(room_version, event, auth_events, do_sig_check=True, do_size_check=Tru
             if not event.signatures.get(event_id_domain):
                 raise AuthError(403, "Event not signed by sending server")
 
-    if auth_events is None:
-        # Oh, we don't know what the state of the room was, so we
-        # are trusting that this is allowed (at least for now)
-        logger.warn("Trusting event: %s", event.event_id)
-        return
-
+    # Implementation of https://matrix.org/docs/spec/rooms/v1#authorization-rules
+    #
+    # 1. If type is m.room.create:
     if event.type == EventTypes.Create:
+        # 1b. If the domain of the room_id does not match the domain of the sender,
+        # reject.
         sender_domain = get_domain_from_id(event.sender)
         room_id_domain = get_domain_from_id(event.room_id)
         if room_id_domain != sender_domain:
@@ -88,37 +114,45 @@ def check(room_version, event, auth_events, do_sig_check=True, do_size_check=Tru
                 403, "Creation event's room_id domain does not match sender's"
             )
 
-        room_version = event.content.get("room_version", "1")
-        if room_version not in KNOWN_ROOM_VERSIONS:
+        # 1c. If content.room_version is present and is not a recognised version, reject
+        room_version_prop = event.content.get("room_version", "1")
+        if room_version_prop not in KNOWN_ROOM_VERSIONS:
             raise AuthError(
-                403, "room appears to have unsupported version %s" % (room_version,)
+                403,
+                "room appears to have unsupported version %s" % (room_version_prop,),
             )
-        # FIXME
+
         logger.debug("Allowing! %s", event)
         return
 
+    # 3. If event does not have a m.room.create in its auth_events, reject.
     creation_event = auth_events.get((EventTypes.Create, ""), None)
-
     if not creation_event:
         raise AuthError(403, "No create event in auth events")
 
+    # additional check for m.federate
     creating_domain = get_domain_from_id(event.room_id)
     originating_domain = get_domain_from_id(event.sender)
     if creating_domain != originating_domain:
         if not _can_federate(event, auth_events):
             raise AuthError(403, "This room has been marked as unfederatable.")
 
-    # FIXME: Temp hack
-    if event.type == EventTypes.Aliases:
+    # 4. If type is m.room.aliases
+    if event.type == EventTypes.Aliases and room_version_obj.special_case_aliases_auth:
+        # 4a. If event has no state_key, reject
         if not event.is_state():
             raise AuthError(403, "Alias event must be a state event")
         if not event.state_key:
             raise AuthError(403, "Alias event must have non-empty state_key")
+
+        # 4b. If sender's domain doesn't matches [sic] state_key, reject
         sender_domain = get_domain_from_id(event.sender)
         if event.state_key != sender_domain:
             raise AuthError(
                 403, "Alias event's state_key does not match sender's domain"
             )
+
+        # 4c. Otherwise, allow.
         logger.debug("Allowing! %s", event)
         return
 
@@ -148,15 +182,15 @@ def check(room_version, event, auth_events, do_sig_check=True, do_size_check=Tru
     _can_send_event(event, auth_events)
 
     if event.type == EventTypes.PowerLevels:
-        _check_power_levels(event, auth_events)
+        _check_power_levels(room_version_obj, event, auth_events)
 
     if event.type == EventTypes.Redaction:
-        check_redaction(room_version, event, auth_events)
+        check_redaction(room_version_obj, event, auth_events)
 
     logger.debug("Allowing! %s", event)
 
 
-def _check_size_limits(event):
+def _check_size_limits(event: EventBase) -> None:
     def too_big(field):
         raise EventSizeError("%s too large" % (field,))
 
@@ -174,13 +208,18 @@ def _check_size_limits(event):
         too_big("event")
 
 
-def _can_federate(event, auth_events):
+def _can_federate(event: EventBase, auth_events: StateMap[EventBase]) -> bool:
     creation_event = auth_events.get((EventTypes.Create, ""))
+    # There should always be a creation event, but if not don't federate.
+    if not creation_event:
+        return False
 
     return creation_event.content.get("m.federate", True) is True
 
 
-def _is_membership_change_allowed(event, auth_events):
+def _is_membership_change_allowed(
+    event: EventBase, auth_events: StateMap[EventBase]
+) -> None:
     membership = event.content["membership"]
 
     # Check if this is the room creator joining:
@@ -306,21 +345,25 @@ def _is_membership_change_allowed(event, auth_events):
         raise AuthError(500, "Unknown membership %s" % membership)
 
 
-def _check_event_sender_in_room(event, auth_events):
+def _check_event_sender_in_room(
+    event: EventBase, auth_events: StateMap[EventBase]
+) -> None:
     key = (EventTypes.Member, event.user_id)
     member_event = auth_events.get(key)
 
-    return _check_joined_room(member_event, event.user_id, event.room_id)
+    _check_joined_room(member_event, event.user_id, event.room_id)
 
 
-def _check_joined_room(member, user_id, room_id):
+def _check_joined_room(member: Optional[EventBase], user_id: str, room_id: str) -> None:
     if not member or member.membership != Membership.JOIN:
         raise AuthError(
             403, "User %s not in room %s (%s)" % (user_id, room_id, repr(member))
         )
 
 
-def get_send_level(etype, state_key, power_levels_event):
+def get_send_level(
+    etype: str, state_key: Optional[str], power_levels_event: Optional[EventBase]
+) -> int:
     """Get the power level required to send an event of a given type
 
     The federation spec [1] refers to this as "Required Power Level".
@@ -328,13 +371,13 @@ def get_send_level(etype, state_key, power_levels_event):
     https://matrix.org/docs/spec/server_server/unstable.html#definitions
 
     Args:
-        etype (str): type of event
-        state_key (str|None): state_key of state event, or None if it is not
+        etype: type of event
+        state_key: state_key of state event, or None if it is not
             a state event.
-        power_levels_event (synapse.events.EventBase|None): power levels event
+        power_levels_event: power levels event
             in force at this point in the room
     Returns:
-        int: power level required to send this event.
+        power level required to send this event.
     """
 
     if power_levels_event:
@@ -355,7 +398,7 @@ def get_send_level(etype, state_key, power_levels_event):
     return int(send_level)
 
 
-def _can_send_event(event, auth_events):
+def _can_send_event(event: EventBase, auth_events: StateMap[EventBase]) -> bool:
     power_levels_event = _get_power_level_event(auth_events)
 
     send_level = get_send_level(event.type, event.get("state_key"), power_levels_event)
@@ -377,7 +420,9 @@ def _can_send_event(event, auth_events):
     return True
 
 
-def check_redaction(room_version, event, auth_events):
+def check_redaction(
+    room_version_obj: RoomVersion, event: EventBase, auth_events: StateMap[EventBase],
+) -> bool:
     """Check whether the event sender is allowed to redact the target event.
 
     Returns:
@@ -397,11 +442,7 @@ def check_redaction(room_version, event, auth_events):
     if user_level >= redact_level:
         return False
 
-    v = KNOWN_ROOM_VERSIONS.get(room_version)
-    if not v:
-        raise RuntimeError("Unrecognized room version %r" % (room_version,))
-
-    if v.event_format == EventFormatVersions.V1:
+    if room_version_obj.event_format == EventFormatVersions.V1:
         redacter_domain = get_domain_from_id(event.event_id)
         redactee_domain = get_domain_from_id(event.redacts)
         if redacter_domain == redactee_domain:
@@ -413,7 +454,9 @@ def check_redaction(room_version, event, auth_events):
     raise AuthError(403, "You don't have permission to redact events")
 
 
-def _check_power_levels(event, auth_events):
+def _check_power_levels(
+    room_version_obj: RoomVersion, event: EventBase, auth_events: StateMap[EventBase],
+) -> None:
     user_list = event.content.get("users", {})
     # Validate users
     for k, v in user_list.items():
@@ -444,7 +487,7 @@ def _check_power_levels(event, auth_events):
         ("redact", None),
         ("kick", None),
         ("invite", None),
-    ]
+    ]  # type: List[Tuple[str, Optional[str]]]
 
     old_list = current_state.content.get("users", {})
     for user in set(list(old_list) + list(user_list)):
@@ -455,6 +498,14 @@ def _check_power_levels(event, auth_events):
     for ev_id in set(list(old_list) + list(new_list)):
         levels_to_check.append((ev_id, "events"))
 
+    # MSC2209 specifies these checks should also be done for the "notifications"
+    # key.
+    if room_version_obj.limit_notifications_power_levels:
+        old_list = current_state.content.get("notifications", {})
+        new_list = event.content.get("notifications", {})
+        for ev_id in set(list(old_list) + list(new_list)):
+            levels_to_check.append((ev_id, "notifications"))
+
     old_state = current_state.content
     new_state = event.content
 
@@ -466,12 +517,12 @@ def _check_power_levels(event, auth_events):
             new_loc = new_loc.get(dir, {})
 
         if level_to_check in old_loc:
-            old_level = int(old_loc[level_to_check])
+            old_level = int(old_loc[level_to_check])  # type: Optional[int]
         else:
             old_level = None
 
         if level_to_check in new_loc:
-            new_level = int(new_loc[level_to_check])
+            new_level = int(new_loc[level_to_check])  # type: Optional[int]
         else:
             new_level = None
 
@@ -493,26 +544,25 @@ def _check_power_levels(event, auth_events):
         new_level_too_big = new_level is not None and new_level > user_level
         if old_level_too_big or new_level_too_big:
             raise AuthError(
-                403,
-                "You don't have permission to add ops level greater " "than your own",
+                403, "You don't have permission to add ops level greater than your own"
             )
 
 
-def _get_power_level_event(auth_events):
+def _get_power_level_event(auth_events: StateMap[EventBase]) -> Optional[EventBase]:
     return auth_events.get((EventTypes.PowerLevels, ""))
 
 
-def get_user_power_level(user_id, auth_events):
+def get_user_power_level(user_id: str, auth_events: StateMap[EventBase]) -> int:
     """Get a user's power level
 
     Args:
-        user_id (str): user's id to look up in power_levels
-        auth_events (dict[(str, str), synapse.events.EventBase]):
+        user_id: user's id to look up in power_levels
+        auth_events:
             state in force at this point in the room (or rather, a subset of
             it including at least the create event and power levels event.
 
     Returns:
-        int: the user's power level in this room.
+        the user's power level in this room.
     """
     power_level_event = _get_power_level_event(auth_events)
     if power_level_event:
@@ -538,7 +588,7 @@ def get_user_power_level(user_id, auth_events):
             return 0
 
 
-def _get_named_level(auth_events, name, default):
+def _get_named_level(auth_events: StateMap[EventBase], name: str, default: int) -> int:
     power_level_event = _get_power_level_event(auth_events)
 
     if not power_level_event:
@@ -551,7 +601,7 @@ def _get_named_level(auth_events, name, default):
         return default
 
 
-def _verify_third_party_invite(event, auth_events):
+def _verify_third_party_invite(event: EventBase, auth_events: StateMap[EventBase]):
     """
     Validates that the invite event is authorized by a previous third-party invite.
 
@@ -626,7 +676,7 @@ def get_public_keys(invite_event):
     return public_keys
 
 
-def auth_types_for_event(event):
+def auth_types_for_event(event: EventBase) -> Set[Tuple[str, str]]:
     """Given an event, return a list of (EventType, StateKey) that may be
     needed to auth the event. The returned list may be a superset of what
     would actually be required depending on the full state of the room.
@@ -635,20 +685,20 @@ def auth_types_for_event(event):
     actually auth the event.
     """
     if event.type == EventTypes.Create:
-        return []
+        return set()
 
-    auth_types = [
+    auth_types = {
         (EventTypes.PowerLevels, ""),
         (EventTypes.Member, event.sender),
         (EventTypes.Create, ""),
-    ]
+    }
 
     if event.type == EventTypes.Member:
         membership = event.content["membership"]
         if membership in [Membership.JOIN, Membership.INVITE]:
-            auth_types.append((EventTypes.JoinRules, ""))
+            auth_types.add((EventTypes.JoinRules, ""))
 
-        auth_types.append((EventTypes.Member, event.state_key))
+        auth_types.add((EventTypes.Member, event.state_key))
 
         if membership == Membership.INVITE:
             if "third_party_invite" in event.content:
@@ -656,6 +706,6 @@ def auth_types_for_event(event):
                     EventTypes.ThirdPartyInvite,
                     event.content["third_party_invite"]["signed"]["token"],
                 )
-                auth_types.append(key)
+                auth_types.add(key)
 
     return auth_types