forked-synapse/synapse/rest/media/v1/download_resource.py
Jérémy Farnaud 6cf261930a added "media-src: 'self'" to CSP for resources (#3578)
Synapse doesn’t allow for media resources to be played directly from
Chrome. It is a problem for users on other networks (e.g. IRC)
communicating with Matrix users through a gateway. The gateway sends
them the raw URL for the resource when a Matrix user uploads a video
and the video cannot be played directly in Chrome using that URL.

Chrome argues it is not authorized to play the video because of the
Content Security Policy. Chrome checks for the "media-src" policy which
is missing, and defauts to the "default-src" policy which is "none".

As Synapse already sends "object-src: 'self'" I thought it wouldn’t be
a problem to add "media-src: 'self'" to the CSP to fix this problem.
2018-09-25 11:55:02 +01:00

73 lines
2.4 KiB
Python

# -*- coding: utf-8 -*-
# Copyright 2014-2016 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 twisted.internet import defer
from twisted.web.resource import Resource
from twisted.web.server import NOT_DONE_YET
import synapse.http.servlet
from synapse.http.server import set_cors_headers, wrap_json_request_handler
from ._base import parse_media_id, respond_404
logger = logging.getLogger(__name__)
class DownloadResource(Resource):
isLeaf = True
def __init__(self, hs, media_repo):
Resource.__init__(self)
self.media_repo = media_repo
self.server_name = hs.hostname
# this is expected by @wrap_json_request_handler
self.clock = hs.get_clock()
def render_GET(self, request):
self._async_render_GET(request)
return NOT_DONE_YET
@wrap_json_request_handler
@defer.inlineCallbacks
def _async_render_GET(self, request):
set_cors_headers(request)
request.setHeader(
b"Content-Security-Policy",
b"default-src 'none';"
b" script-src 'none';"
b" plugin-types application/pdf;"
b" style-src 'unsafe-inline';"
b" media-src 'self';"
b" object-src 'self';"
)
server_name, media_id, name = parse_media_id(request)
if server_name == self.server_name:
yield self.media_repo.get_local_media(request, media_id, name)
else:
allow_remote = synapse.http.servlet.parse_boolean(
request, "allow_remote", default=True)
if not allow_remote:
logger.info(
"Rejecting request for remote media %s/%s due to allow_remote",
server_name, media_id,
)
respond_404(request)
return
yield self.media_repo.get_remote_media(request, server_name, media_id, name)