def event_from_pdu_json(
pdu_json: JsonDict, room_version: RoomVersion, outlier: bool = False
) -> EventBase:
"""Construct an EventBase from an event json received over federation
Args:
pdu_json: pdu as received over federation
room_version: The version of the room this event belongs to
outlier: True to mark this event as an outlier
Raises:
SynapseError: if the pdu is missing required fields or is otherwise
not a valid matrix event
"""
# we could probably enforce a bunch of other fields here (room_id, sender,
# origin, etc etc)
assert_params_in_dict(pdu_json, ("type", "depth"))
depth = pdu_json["depth"]
if not isinstance(depth, int):
raise SynapseError(400, "Depth %r not an intger" % (depth,), Codes.BAD_JSON)
if depth < 0:
raise SynapseError(400, "Depth too small", Codes.BAD_JSON)
elif depth > MAX_DEPTH:
raise SynapseError(400, "Depth too large", Codes.BAD_JSON)
# Validate that the JSON conforms to the specification.
if room_version.strict_canonicaljson:
validate_canonicaljson(pdu_json)
event = make_event_from_dict(pdu_json, room_version)
event.internal_metadata.outlier = outlier
return event
def validate_new(self, event: EventBase, config: HomeServerConfig):
"""Validates the event has roughly the right format
Args:
event: The event to validate.
config: The homeserver's configuration.
"""
self.validate_builder(event)
if event.format_version == EventFormatVersions.V1:
EventID.from_string(event.event_id)
required = [
"auth_events",
"content",
"hashes",
"origin",
"prev_events",
"sender",
"type",
]
for k in required:
if not hasattr(event, k):
raise SynapseError(400, "Event does not have key %s" % (k,))
# Check that the following keys have string values
event_strings = ["origin"]
for s in event_strings:
if not isinstance(getattr(event, s), str):
raise SynapseError(400, "'%s' not a string type" % (s,))
# Depending on the room version, ensure the data is spec compliant JSON.
if event.room_version.strict_canonicaljson:
# Note that only the client controlled portion of the event is
# checked, since we trust the portions of the event we created.
validate_canonicaljson(event.content)
if event.type == EventTypes.Aliases:
if "aliases" in event.content:
for alias in event.content["aliases"]:
if len(alias) > MAX_ALIAS_LENGTH:
raise SynapseError(
400,
(
"Can't create aliases longer than"
" %d characters" % (MAX_ALIAS_LENGTH,)
),
Codes.INVALID_PARAM,
)
if event.type == EventTypes.Retention:
self._validate_retention(event)
if event.type == EventTypes.ServerACL:
if not server_matches_acl_event(config.server_name, event):
raise SynapseError(
400, "Can't create an ACL event that denies the local server"
)
def event_from_pdu_json(pdu_json: JsonDict, room_version: RoomVersion) -> EventBase:
"""Construct an EventBase from an event json received over federation
Args:
pdu_json: pdu as received over federation
room_version: The version of the room this event belongs to
Raises:
SynapseError: if the pdu is missing required fields or is otherwise
not a valid matrix event
"""
# we could probably enforce a bunch of other fields here (room_id, sender,
# origin, etc etc)
assert_params_in_dict(pdu_json, ("type", "depth"))
# Strip any unauthorized values from "unsigned" if they exist
if "unsigned" in pdu_json:
_strip_unsigned_values(pdu_json)
depth = pdu_json["depth"]
if not isinstance(depth, int):
raise SynapseError(400, "Depth %r not an intger" % (depth,), Codes.BAD_JSON)
if depth < 0:
raise SynapseError(400, "Depth too small", Codes.BAD_JSON)
elif depth > MAX_DEPTH:
raise SynapseError(400, "Depth too large", Codes.BAD_JSON)
# Validate that the JSON conforms to the specification.
if room_version.strict_canonicaljson:
validate_canonicaljson(pdu_json)
event = make_event_from_dict(pdu_json, room_version)
return event
def validate_new(self, event: EventBase, config: HomeServerConfig) -> None:
"""Validates the event has roughly the right format
Suitable for checking a locally-created event. It has stricter checks than
is appropriate for an event received over federation (for which, see
event_auth.validate_event_for_room_version)
Args:
event: The event to validate.
config: The homeserver's configuration.
"""
self.validate_builder(event)
if event.format_version == EventFormatVersions.V1:
EventID.from_string(event.event_id)
required = [
"auth_events",
"content",
"hashes",
"origin",
"prev_events",
"sender",
"type",
]
for k in required:
if k not in event:
raise SynapseError(400, "Event does not have key %s" % (k, ))
# Check that the following keys have string values
event_strings = ["origin"]
for s in event_strings:
if not isinstance(getattr(event, s), str):
raise SynapseError(400, "'%s' not a string type" % (s, ))
# Depending on the room version, ensure the data is spec compliant JSON.
if event.room_version.strict_canonicaljson:
# Note that only the client controlled portion of the event is
# checked, since we trust the portions of the event we created.
validate_canonicaljson(event.content)
if event.type == EventTypes.Aliases:
if "aliases" in event.content:
for alias in event.content["aliases"]:
if len(alias) > MAX_ALIAS_LENGTH:
raise SynapseError(
400,
("Can't create aliases longer than"
" %d characters" % (MAX_ALIAS_LENGTH, )),
Codes.INVALID_PARAM,
)
if event.type == EventTypes.Retention:
self._validate_retention(event)
if event.type == EventTypes.ServerACL:
if not server_matches_acl_event(config.server.server_name, event):
raise SynapseError(
400,
"Can't create an ACL event that denies the local server")
if event.type == EventTypes.PowerLevels:
try:
jsonschema.validate(
instance=event.content,
schema=POWER_LEVELS_SCHEMA,
cls=plValidator,
)
except jsonschema.ValidationError as e:
if e.path:
# example: "users_default": '0' is not of type 'integer'
# cast safety: path entries can be integers, if we fail to validate
# items in an array. However the POWER_LEVELS_SCHEMA doesn't expect
# to see any arrays.
message = (
'"' + cast(str, e.path[-1]) + '": ' +
e.message # noqa: B306
)
# jsonschema.ValidationError.message is a valid attribute
else:
# example: '0' is not of type 'integer'
message = e.message # noqa: B306
# jsonschema.ValidationError.message is a valid attribute
raise SynapseError(
code=400,
msg=message,
errcode=Codes.BAD_JSON,
)
