148 lines
4.9 KiB
Python
148 lines
4.9 KiB
Python
# -*- coding: utf-8 -*-
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# Copyright 2014-2016 OpenMarket Ltd
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#
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# Licensed under the Apache License, Version 2.0 (the "License");
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# you may not use this file except in compliance with the License.
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# You may obtain a copy of the License at
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#
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# http://www.apache.org/licenses/LICENSE-2.0
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#
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# Unless required by applicable law or agreed to in writing, software
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# distributed under the License is distributed on an "AS IS" BASIS,
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# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
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# See the License for the specific language governing permissions and
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# limitations under the License.
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import logging
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from canonicaljson import json
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from twisted.internet import defer, reactor
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from twisted.internet.error import ConnectError
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from twisted.internet.protocol import Factory
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from twisted.names.error import DomainError
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from twisted.web.http import HTTPClient
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from synapse.http.endpoint import matrix_federation_endpoint
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from synapse.util import logcontext
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logger = logging.getLogger(__name__)
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KEY_API_V1 = b"/_matrix/key/v1/"
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@defer.inlineCallbacks
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def fetch_server_key(server_name, tls_client_options_factory, path=KEY_API_V1):
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"""Fetch the keys for a remote server."""
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factory = SynapseKeyClientFactory()
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factory.path = path
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factory.host = server_name
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endpoint = matrix_federation_endpoint(
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reactor, server_name, tls_client_options_factory, timeout=30
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)
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for i in range(5):
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try:
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with logcontext.PreserveLoggingContext():
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protocol = yield endpoint.connect(factory)
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server_response, server_certificate = yield protocol.remote_key
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defer.returnValue((server_response, server_certificate))
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except SynapseKeyClientError as e:
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logger.warn("Error getting key for %r: %s", server_name, e)
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if e.status.startswith(b"4"):
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# Don't retry for 4xx responses.
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raise IOError("Cannot get key for %r" % server_name)
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except (ConnectError, DomainError) as e:
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logger.warn("Error getting key for %r: %s", server_name, e)
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except Exception as e:
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logger.exception("Error getting key for %r", server_name)
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raise IOError("Cannot get key for %r" % server_name)
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class SynapseKeyClientError(Exception):
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"""The key wasn't retrieved from the remote server."""
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status = None
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pass
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class SynapseKeyClientProtocol(HTTPClient):
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"""Low level HTTPS client which retrieves an application/json response from
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the server and extracts the X.509 certificate for the remote peer from the
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SSL connection."""
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timeout = 30
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def __init__(self):
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self.remote_key = defer.Deferred()
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self.host = None
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self._peer = None
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def connectionMade(self):
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self._peer = self.transport.getPeer()
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logger.debug("Connected to %s", self._peer)
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if not isinstance(self.path, bytes):
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self.path = self.path.encode('ascii')
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if not isinstance(self.host, bytes):
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self.host = self.host.encode('ascii')
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self.sendCommand(b"GET", self.path)
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if self.host:
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self.sendHeader(b"Host", self.host)
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self.endHeaders()
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self.timer = reactor.callLater(
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self.timeout,
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self.on_timeout
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)
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def errback(self, error):
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if not self.remote_key.called:
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self.remote_key.errback(error)
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def callback(self, result):
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if not self.remote_key.called:
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self.remote_key.callback(result)
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def handleStatus(self, version, status, message):
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if status != b"200":
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# logger.info("Non-200 response from %s: %s %s",
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# self.transport.getHost(), status, message)
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error = SynapseKeyClientError(
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"Non-200 response %r from %r" % (status, self.host)
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)
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error.status = status
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self.errback(error)
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self.transport.abortConnection()
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def handleResponse(self, response_body_bytes):
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try:
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json_response = json.loads(response_body_bytes)
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except ValueError:
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# logger.info("Invalid JSON response from %s",
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# self.transport.getHost())
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self.transport.abortConnection()
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return
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certificate = self.transport.getPeerCertificate()
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self.callback((json_response, certificate))
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self.transport.abortConnection()
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self.timer.cancel()
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def on_timeout(self):
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logger.debug(
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"Timeout waiting for response from %s: %s",
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self.host, self._peer,
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)
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self.errback(IOError("Timeout waiting for response"))
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self.transport.abortConnection()
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class SynapseKeyClientFactory(Factory):
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def protocol(self):
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protocol = SynapseKeyClientProtocol()
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protocol.path = self.path
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protocol.host = self.host
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return protocol
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