diff options
Diffstat (limited to 'synapse/rest/key/v2/remote_key_resource.py')
| -rw-r--r-- | synapse/rest/key/v2/remote_key_resource.py | 242 |
1 files changed, 242 insertions, 0 deletions
diff --git a/synapse/rest/key/v2/remote_key_resource.py b/synapse/rest/key/v2/remote_key_resource.py new file mode 100644 index 0000000000..e434847b45 --- /dev/null +++ b/synapse/rest/key/v2/remote_key_resource.py @@ -0,0 +1,242 @@ +# Copyright 2015 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. + +from synapse.http.server import request_handler, respond_with_json_bytes +from synapse.http.servlet import parse_integer +from synapse.api.errors import SynapseError, Codes + +from twisted.web.resource import Resource +from twisted.web.server import NOT_DONE_YET +from twisted.internet import defer + + +from io import BytesIO +import json +import logging +logger = logging.getLogger(__name__) + + +class RemoteKey(Resource): + """HTTP resource for retreiving the TLS certificate and NACL signature + verification keys for a collection of servers. Checks that the reported + X.509 TLS certificate matches the one used in the HTTPS connection. Checks + that the NACL signature for the remote server is valid. Returns a dict of + JSON signed by both the remote server and by this server. + + Supports individual GET APIs and a bulk query POST API. + + Requsts: + + GET /_matrix/key/v2/query/remote.server.example.com HTTP/1.1 + + GET /_matrix/key/v2/query/remote.server.example.com/a.key.id HTTP/1.1 + + POST /_matrix/v2/query HTTP/1.1 + Content-Type: application/json + { + "server_keys": { + "remote.server.example.com": { + "a.key.id": { + "minimum_valid_until_ts": 1234567890123 + } + } + } + } + + Response: + + HTTP/1.1 200 OK + Content-Type: application/json + { + "server_keys": [ + { + "server_name": "remote.server.example.com" + "valid_until_ts": # posix timestamp + "verify_keys": { + "a.key.id": { # The identifier for a key. + key: "" # base64 encoded verification key. + } + } + "old_verify_keys": { + "an.old.key.id": { # The identifier for an old key. + key: "", # base64 encoded key + "expired_ts": 0, # when the key stop being used. + } + } + "tls_fingerprints": [ + { "sha256": # fingerprint } + ] + "signatures": { + "remote.server.example.com": {...} + "this.server.example.com": {...} + } + } + ] + } + """ + + isLeaf = True + + def __init__(self, hs): + self.keyring = hs.get_keyring() + self.store = hs.get_datastore() + self.version_string = hs.version_string + self.clock = hs.get_clock() + + def render_GET(self, request): + self.async_render_GET(request) + return NOT_DONE_YET + + @request_handler + @defer.inlineCallbacks + def async_render_GET(self, request): + if len(request.postpath) == 1: + server, = request.postpath + query = {server: {}} + elif len(request.postpath) == 2: + server, key_id = request.postpath + minimum_valid_until_ts = parse_integer( + request, "minimum_valid_until_ts" + ) + arguments = {} + if minimum_valid_until_ts is not None: + arguments["minimum_valid_until_ts"] = minimum_valid_until_ts + query = {server: {key_id: arguments}} + else: + raise SynapseError( + 404, "Not found %r" % request.postpath, Codes.NOT_FOUND + ) + yield self.query_keys(request, query, query_remote_on_cache_miss=True) + + def render_POST(self, request): + self.async_render_POST(request) + return NOT_DONE_YET + + @request_handler + @defer.inlineCallbacks + def async_render_POST(self, request): + try: + content = json.loads(request.content.read()) + if type(content) != dict: + raise ValueError() + except ValueError: + raise SynapseError( + 400, "Content must be JSON object.", errcode=Codes.NOT_JSON + ) + + query = content["server_keys"] + + yield self.query_keys(request, query, query_remote_on_cache_miss=True) + + @defer.inlineCallbacks + def query_keys(self, request, query, query_remote_on_cache_miss=False): + logger.info("Handling query for keys %r", query) + store_queries = [] + for server_name, key_ids in query.items(): + if not key_ids: + key_ids = (None,) + for key_id in key_ids: + store_queries.append((server_name, key_id, None)) + + cached = yield self.store.get_server_keys_json(store_queries) + + json_results = set() + + time_now_ms = self.clock.time_msec() + + cache_misses = dict() + for (server_name, key_id, from_server), results in cached.items(): + results = [ + (result["ts_added_ms"], result) for result in results + ] + + if not results and key_id is not None: + cache_misses.setdefault(server_name, set()).add(key_id) + continue + + if key_id is not None: + ts_added_ms, most_recent_result = max(results) + ts_valid_until_ms = most_recent_result["ts_valid_until_ms"] + req_key = query.get(server_name, {}).get(key_id, {}) + req_valid_until = req_key.get("minimum_valid_until_ts") + miss = False + if req_valid_until is not None: + if ts_valid_until_ms < req_valid_until: + logger.debug( + "Cached response for %r/%r is older than requested" + ": valid_until (%r) < minimum_valid_until (%r)", + server_name, key_id, + ts_valid_until_ms, req_valid_until + ) + miss = True + else: + logger.debug( + "Cached response for %r/%r is newer than requested" + ": valid_until (%r) >= minimum_valid_until (%r)", + server_name, key_id, + ts_valid_until_ms, req_valid_until + ) + elif (ts_added_ms + ts_valid_until_ms) / 2 < time_now_ms: + logger.debug( + "Cached response for %r/%r is too old" + ": (added (%r) + valid_until (%r)) / 2 < now (%r)", + server_name, key_id, + ts_added_ms, ts_valid_until_ms, time_now_ms + ) + # We more than half way through the lifetime of the + # response. We should fetch a fresh copy. + miss = True + else: + logger.debug( + "Cached response for %r/%r is still valid" + ": (added (%r) + valid_until (%r)) / 2 < now (%r)", + server_name, key_id, + ts_added_ms, ts_valid_until_ms, time_now_ms + ) + + if miss: + cache_misses.setdefault(server_name, set()).add(key_id) + json_results.add(bytes(most_recent_result["key_json"])) + else: + for ts_added, result in results: + json_results.add(bytes(result["key_json"])) + + if cache_misses and query_remote_on_cache_miss: + for server_name, key_ids in cache_misses.items(): + try: + yield self.keyring.get_server_verify_key_v2_direct( + server_name, key_ids + ) + except: + logger.exception("Failed to get key for %r", server_name) + pass + yield self.query_keys( + request, query, query_remote_on_cache_miss=False + ) + else: + result_io = BytesIO() + result_io.write(b"{\"server_keys\":") + sep = b"[" + for json_bytes in json_results: + result_io.write(sep) + result_io.write(json_bytes) + sep = b"," + if sep == b"[": + result_io.write(sep) + result_io.write(b"]}") + + respond_with_json_bytes( + request, 200, result_io.getvalue(), + version_string=self.version_string + ) |