243 lines
		
	
	
		
			8.7 KiB
		
	
	
	
		
			Python
		
	
	
			
		
		
	
	
			243 lines
		
	
	
		
			8.7 KiB
		
	
	
	
		
			Python
		
	
	
# Copyright 2015, 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.
 | 
						|
 | 
						|
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
 | 
						|
            )
 |