SYN-75 Verify signatures on server to server transactions

This commit is contained in:
Mark Haines 2014-09-30 15:15:10 +01:00
parent 52ca867670
commit b95a178584
14 changed files with 245 additions and 235 deletions

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@ -15,9 +15,10 @@
from twisted.web.http import HTTPClient
from twisted.internet.protocol import Factory
from twisted.internet import defer, reactor
from twisted.internet.protocol import ClientFactory
from twisted.names.srvconnect import SRVConnector
from twisted.internet.endpoints import connectProtocol
from synapse.http.endpoint import matrix_endpoint
import json
import logging
@ -30,15 +31,19 @@ def fetch_server_key(server_name, ssl_context_factory):
"""Fetch the keys for a remote server."""
factory = SynapseKeyClientFactory()
endpoint = matrix_endpoint(
reactor, server_name, ssl_context_factory, timeout=30
)
SRVConnector(
reactor, "matrix", server_name, factory,
protocol="tcp", connectFuncName="connectSSL", defaultPort=443,
connectFuncKwArgs=dict(contextFactory=ssl_context_factory)).connect()
server_key, server_certificate = yield factory.remote_key
defer.returnValue((server_key, server_certificate))
for i in range(5):
try:
protocol = yield endpoint.connect(factory)
server_response, server_certificate = yield protocol.remote_key
defer.returnValue((server_response, server_certificate))
return
except Exception as e:
logger.exception(e)
raise IOError("Cannot get key for " % server_name)
class SynapseKeyClientError(Exception):
@ -51,69 +56,47 @@ class SynapseKeyClientProtocol(HTTPClient):
the server and extracts the X.509 certificate for the remote peer from the
SSL connection."""
timeout = 30
def __init__(self):
self.remote_key = defer.Deferred()
def connectionMade(self):
logger.debug("Connected to %s", self.transport.getHost())
self.sendCommand(b"GET", b"/key")
self.sendCommand(b"GET", b"/_matrix/key/v1/")
self.endHeaders()
self.timer = reactor.callLater(
self.factory.timeout_seconds,
self.timeout,
self.on_timeout
)
def handleStatus(self, version, status, message):
if status != b"200":
logger.info("Non-200 response from %s: %s %s",
self.transport.getHost(), status, message)
#logger.info("Non-200 response from %s: %s %s",
# self.transport.getHost(), status, message)
self.transport.abortConnection()
def handleResponse(self, response_body_bytes):
try:
json_response = json.loads(response_body_bytes)
except ValueError:
logger.info("Invalid JSON response from %s",
self.transport.getHost())
#logger.info("Invalid JSON response from %s",
# self.transport.getHost())
self.transport.abortConnection()
return
certificate = self.transport.getPeerCertificate()
self.factory.on_remote_key((json_response, certificate))
self.remote_key.callback((json_response, certificate))
self.transport.abortConnection()
self.timer.cancel()
def on_timeout(self):
logger.debug("Timeout waiting for response from %s",
self.transport.getHost())
self.on_remote_key.errback(IOError("Timeout waiting for response"))
self.transport.abortConnection()
class SynapseKeyClientFactory(ClientFactory):
class SynapseKeyClientFactory(Factory):
protocol = SynapseKeyClientProtocol
max_retries = 5
timeout_seconds = 30
def __init__(self):
self.succeeded = False
self.retries = 0
self.remote_key = defer.Deferred()
def on_remote_key(self, key):
self.succeeded = True
self.remote_key.callback(key)
def retry_connection(self, connector):
self.retries += 1
if self.retries < self.max_retries:
connector.connector = None
connector.connect()
else:
self.remote_key.errback(
SynapseKeyClientError("Max retries exceeded"))
def clientConnectionFailed(self, connector, reason):
logger.info("Connection failed %s", reason)
self.retry_connection(connector)
def clientConnectionLost(self, connector, reason):
logger.info("Connection lost %s", reason)
if not self.succeeded:
self.retry_connection(connector)

125
synapse/crypto/keyring.py Normal file
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@ -0,0 +1,125 @@
# -*- coding: utf-8 -*-
# Copyright 2014 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.crypto.keyclient import fetch_server_key
from twisted.internet import defer
from syutil.crypto.jsonsign import verify_signed_json, signature_ids
from syutil.crypto.signing_key import (
is_signing_algorithm_supported, decode_verify_key_bytes
)
from syutil.base64util import decode_base64, encode_base64
from OpenSSL import crypto
import logging
logger = logging.getLogger(__name__)
class Keyring(object):
def __init__(self, hs):
self.store = hs.get_datastore()
self.clock = hs.get_clock()
self.hs = hs
@defer.inlineCallbacks
def verify_json_for_server(self, server_name, json_object):
key_ids = signature_ids(json_object, server_name)
verify_key = yield self.get_server_verify_key(server_name, key_ids)
verify_signed_json(json_object, server_name, verify_key)
@defer.inlineCallbacks
def get_server_verify_key(self, server_name, key_ids):
"""Finds a verification key for the server with one of the key ids.
Args:
server_name (str): The name of the server to fetch a key for.
keys_ids (list of str): The key_ids to check for.
"""
# Check the datastore to see if we have one cached.
cached = yield self.store.get_server_verify_keys(server_name, key_ids)
if cached:
defer.returnValue(cached[0])
return
# Try to fetch the key from the remote server.
# TODO(markjh): Ratelimit requests to a given server.
(response, tls_certificate) = yield fetch_server_key(
server_name, self.hs.tls_context_factory
)
# Check the response.
x509_certificate_bytes = crypto.dump_certificate(
crypto.FILETYPE_ASN1, tls_certificate
)
if ("signatures" not in response
or server_name not in response["signatures"]):
raise ValueError("Key response not signed by remote server")
if "tls_certificate" not in response:
raise ValueError("Key response missing TLS certificate")
tls_certificate_b64 = response["tls_certificate"]
if encode_base64(x509_certificate_bytes) != tls_certificate_b64:
raise ValueError("TLS certificate doesn't match")
verify_keys = {}
for key_id, key_base64 in response["verify_keys"].items():
if is_signing_algorithm_supported(key_id):
key_bytes = decode_base64(key_base64)
verify_key = decode_verify_key_bytes(key_id, key_bytes)
verify_keys[key_id] = verify_key
for key_id in response["signatures"][server_name]:
if key_id not in response["verify_keys"]:
raise ValueError(
"Key response must include verification keys for all"
" signatures"
)
if key_id in verify_keys:
verify_signed_json(
response,
server_name,
verify_keys[key_id]
)
# Cache the result in the datastore.
time_now_ms = self.clock.time_msec()
self.store.store_server_certificate(
server_name,
server_name,
time_now_ms,
tls_certificate,
)
for key_id, key in verify_keys.items():
self.store.store_server_verify_key(
server_name, server_name, time_now_ms, key
)
for key_id in key_ids:
if key_id in verify_keys:
defer.returnValue(verify_keys[key_id])
return
raise ValueError("No verification key found for given key ids")

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@ -1,111 +0,0 @@
# -*- coding: utf-8 -*-
# Copyright 2014 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 twisted.internet import reactor, ssl
from twisted.web import server
from twisted.web.resource import Resource
from twisted.python.log import PythonLoggingObserver
from synapse.crypto.resource.key import LocalKey
from synapse.crypto.config import load_config
from syutil.base64util import decode_base64
from OpenSSL import crypto, SSL
import logging
import nacl.signing
import sys
class KeyServerSSLContextFactory(ssl.ContextFactory):
"""Factory for PyOpenSSL SSL contexts that are used to handle incoming
connections and to make connections to remote servers."""
def __init__(self, key_server):
self._context = SSL.Context(SSL.SSLv23_METHOD)
self.configure_context(self._context, key_server)
@staticmethod
def configure_context(context, key_server):
context.set_options(SSL.OP_NO_SSLv2 | SSL.OP_NO_SSLv3)
context.use_certificate(key_server.tls_certificate)
context.use_privatekey(key_server.tls_private_key)
context.load_tmp_dh(key_server.tls_dh_params_path)
context.set_cipher_list("!ADH:HIGH+kEDH:!AECDH:HIGH+kEECDH")
def getContext(self):
return self._context
class KeyServer(object):
"""An HTTPS server serving LocalKey and RemoteKey resources."""
def __init__(self, server_name, tls_certificate_path, tls_private_key_path,
tls_dh_params_path, signing_key_path, bind_host, bind_port):
self.server_name = server_name
self.tls_certificate = self.read_tls_certificate(tls_certificate_path)
self.tls_private_key = self.read_tls_private_key(tls_private_key_path)
self.tls_dh_params_path = tls_dh_params_path
self.signing_key = self.read_signing_key(signing_key_path)
self.bind_host = bind_host
self.bind_port = int(bind_port)
self.ssl_context_factory = KeyServerSSLContextFactory(self)
@staticmethod
def read_tls_certificate(cert_path):
with open(cert_path) as cert_file:
cert_pem = cert_file.read()
return crypto.load_certificate(crypto.FILETYPE_PEM, cert_pem)
@staticmethod
def read_tls_private_key(private_key_path):
with open(private_key_path) as private_key_file:
private_key_pem = private_key_file.read()
return crypto.load_privatekey(crypto.FILETYPE_PEM, private_key_pem)
@staticmethod
def read_signing_key(signing_key_path):
with open(signing_key_path) as signing_key_file:
signing_key_b64 = signing_key_file.read()
signing_key_bytes = decode_base64(signing_key_b64)
return nacl.signing.SigningKey(signing_key_bytes)
def run(self):
root = Resource()
root.putChild("key", LocalKey(self))
site = server.Site(root)
reactor.listenSSL(
self.bind_port,
site,
self.ssl_context_factory,
interface=self.bind_host
)
logging.basicConfig(level=logging.DEBUG)
observer = PythonLoggingObserver()
observer.start()
reactor.run()
def main():
key_server = KeyServer(**load_config(__doc__, sys.argv[1:]))
key_server.run()
if __name__ == "__main__":
main()

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@ -1,15 +0,0 @@
# -*- coding: utf-8 -*-
# Copyright 2014 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.

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@ -66,6 +66,8 @@ class ReplicationLayer(object):
hs, self.transaction_actions, transport_layer
)
self.keyring = hs.get_keyring()
self.handler = None
self.edu_handlers = {}
self.query_handlers = {}
@ -291,6 +293,10 @@ class ReplicationLayer(object):
@defer.inlineCallbacks
@log_function
def on_incoming_transaction(self, transaction_data):
yield self.keyring.verify_json_for_server(
transaction_data["origin"], transaction_data
)
transaction = Transaction(**transaction_data)
for p in transaction.pdus:
@ -590,7 +596,7 @@ class _TransactionQueue(object):
transaction = Transaction.create_new(
ts=self._clock.time_msec(),
transaction_id=self._next_txn_id,
transaction_id=str(self._next_txn_id),
origin=self.server_name,
destination=destination,
pdus=pdus,
@ -611,20 +617,18 @@ class _TransactionQueue(object):
# FIXME (erikj): This is a bit of a hack to make the Pdu age
# keys work
def cb(transaction):
def json_data_cb():
data = transaction.get_dict()
now = int(self._clock.time_msec())
if "pdus" in transaction:
for p in transaction["pdus"]:
if "pdus" in data:
for p in data["pdus"]:
if "age_ts" in p:
p["age"] = now - int(p["age_ts"])
transaction = sign_json(transaction, server_name, signing_key)
return transaction
data = sign_json(data, server_name, signing_key)
return data
code, response = yield self.transport_layer.send_transaction(
transaction,
on_send_callback=cb,
transaction, json_data_cb
)
logger.debug("TX [%s] Sent transaction", destination)

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@ -144,7 +144,7 @@ class TransportLayer(object):
@defer.inlineCallbacks
@log_function
def send_transaction(self, transaction, on_send_callback=None):
def send_transaction(self, transaction, json_data_callback=None):
""" Sends the given Transaction to it's destination
Args:
@ -163,24 +163,26 @@ class TransportLayer(object):
if transaction.destination == self.server_name:
raise RuntimeError("Transport layer cannot send to itself!")
data = transaction.get_dict()
if json_data_callback is None:
def json_data_callback():
return transaction.get_dict()
# FIXME (erikj): This is a bit of a hack to make the Pdu age
# keys work
def cb(destination, method, path_bytes, producer):
if not on_send_callback:
return
json_data = json_data_callback()
del json_data["destination"]
del json_data["transaction_id"]
producer.reset(json_data)
transaction = json.loads(producer.body)
new_transaction = on_send_callback(transaction)
producer.reset(new_transaction)
json_data = transaction.get_dict()
del json_data["destination"]
del json_data["transaction_id"]
code, response = yield self.client.put_json(
transaction.destination,
path=PREFIX + "/send/%s/" % transaction.transaction_id,
data=data,
data=json_data,
on_send_callback=cb,
)

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@ -186,9 +186,6 @@ class Transaction(JsonEncodedObject):
"previous_ids",
"pdus",
"edus",
]
internal_keys = [
"transaction_id",
"destination",
]

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@ -34,6 +34,7 @@ from synapse.util.distributor import Distributor
from synapse.util.lockutils import LockManager
from synapse.streams.events import EventSources
from synapse.api.ratelimiting import Ratelimiter
from synapse.crypto.keyring import Keyring
class BaseHomeServer(object):
@ -78,6 +79,7 @@ class BaseHomeServer(object):
'resource_for_server_key',
'event_sources',
'ratelimiter',
'keyring',
]
def __init__(self, hostname, **kwargs):
@ -201,6 +203,9 @@ class HomeServer(BaseHomeServer):
def build_ratelimiter(self):
return Ratelimiter()
def build_keyring(self):
return Keyring(self)
def register_servlets(self):
""" Register all servlets associated with this HomeServer.
"""

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@ -56,6 +56,7 @@ SCHEMAS = [
"presence",
"im",
"room_aliases",
"keys",
]

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@ -18,7 +18,8 @@ from _base import SQLBaseStore
from twisted.internet import defer
import OpenSSL
import nacl.signing
from syutil.crypto.signing_key import decode_verify_key_bytes
import hashlib
class KeyStore(SQLBaseStore):
"""Persistence for signature verification keys and tls X.509 certificates
@ -42,62 +43,74 @@ class KeyStore(SQLBaseStore):
)
defer.returnValue(tls_certificate)
def store_server_certificate(self, server_name, key_server, ts_now_ms,
def store_server_certificate(self, server_name, from_server, time_now_ms,
tls_certificate):
"""Stores the TLS X.509 certificate for the given server
Args:
server_name (bytes): The name of the server.
key_server (bytes): Where the certificate was looked up
ts_now_ms (int): The time now in milliseconds
server_name (str): The name of the server.
from_server (str): Where the certificate was looked up
time_now_ms (int): The time now in milliseconds
tls_certificate (OpenSSL.crypto.X509): The X.509 certificate.
"""
tls_certificate_bytes = OpenSSL.crypto.dump_certificate(
OpenSSL.crypto.FILETYPE_ASN1, tls_certificate
)
fingerprint = hashlib.sha256(tls_certificate_bytes).hexdigest()
return self._simple_insert(
table="server_tls_certificates",
keyvalues={
values={
"server_name": server_name,
"key_server": key_server,
"ts_added_ms": ts_now_ms,
"tls_certificate": tls_certificate_bytes,
"fingerprint": fingerprint,
"from_server": from_server,
"ts_added_ms": time_now_ms,
"tls_certificate": buffer(tls_certificate_bytes),
},
)
@defer.inlineCallbacks
def get_server_verification_key(self, server_name):
"""Retrieve the NACL verification key for a given server
def get_server_verify_keys(self, server_name, key_ids):
"""Retrieve the NACL verification key for a given server for the given
key_ids
Args:
server_name (bytes): The name of the server.
server_name (str): The name of the server.
key_ids (list of str): List of key_ids to try and look up.
Returns:
(nacl.signing.VerifyKey): The verification key.
(list of VerifyKey): The verification keys.
"""
verification_key_bytes, = yield self._simple_select_one(
table="server_signature_keys",
key_values={"server_name": server_name},
retcols=("tls_certificate",),
sql = (
"SELECT key_id, verify_key FROM server_signature_keys"
" WHERE server_name = ?"
" AND key_id in (" + ",".join("?" for key_id in key_ids) + ")"
)
verification_key = nacl.signing.VerifyKey(verification_key_bytes)
defer.returnValue(verification_key)
def store_server_verification_key(self, server_name, key_version,
key_server, ts_now_ms, verification_key):
rows = yield self._execute_and_decode(sql, server_name, *key_ids)
keys = []
for row in rows:
key_id = row["key_id"]
key_bytes = row["verify_key"]
key = decode_verify_key_bytes(key_id, str(key_bytes))
keys.append(key)
defer.returnValue(keys)
def store_server_verify_key(self, server_name, from_server, time_now_ms,
verify_key):
"""Stores a NACL verification key for the given server.
Args:
server_name (bytes): The name of the server.
key_version (bytes): The version of the key for the server.
key_server (bytes): Where the verification key was looked up
server_name (str): The name of the server.
key_id (str): The version of the key for the server.
from_server (str): Where the verification key was looked up
ts_now_ms (int): The time now in milliseconds
verification_key (nacl.signing.VerifyKey): The NACL verify key.
verification_key (VerifyKey): The NACL verify key.
"""
verification_key_bytes = verification_key.encode()
verify_key_bytes = verify_key.encode()
return self._simple_insert(
table="server_signature_keys",
key_values={
values={
"server_name": server_name,
"key_version": key_version,
"key_server": key_server,
"ts_added_ms": ts_now_ms,
"verification_key": verification_key_bytes,
"key_id": "%s:%s" % (verify_key.alg, verify_key.version),
"from_server": from_server,
"ts_added_ms": time_now_ms,
"verify_key": buffer(verify_key.encode()),
},
)

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@ -14,17 +14,18 @@
*/
CREATE TABLE IF NOT EXISTS server_tls_certificates(
server_name TEXT, -- Server name.
key_server TEXT, -- Which key server the certificate was fetched from.
fingerprint TEXT, -- Certificate fingerprint.
from_server TEXT, -- Which key server the certificate was fetched from.
ts_added_ms INTEGER, -- When the certifcate was added.
tls_certificate BLOB, -- DER encoded x509 certificate.
CONSTRAINT uniqueness UNIQUE (server_name)
CONSTRAINT uniqueness UNIQUE (server_name, fingerprint)
);
CREATE TABLE IF NOT EXISTS server_signature_keys(
server_name TEXT, -- Server name.
key_version TEXT, -- Key version.
key_server TEXT, -- Which key server the key was fetched form.
key_id TEXT, -- Key version.
from_server TEXT, -- Which key server the key was fetched form.
ts_added_ms INTEGER, -- When the key was added.
verification_key BLOB, -- NACL verification key.
CONSTRAINT uniqueness UNIQUE (server_name, key_version)
verify_key BLOB, -- NACL verification key.
CONSTRAINT uniqueness UNIQUE (server_name, key_id)
);

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@ -74,6 +74,7 @@ class FederationTestCase(unittest.TestCase):
datastore=self.mock_persistence,
clock=self.clock,
config=self.mock_config,
keyring=Mock(),
)
self.federation = initialize_http_replication(hs)
self.distributor = hs.get_distributor()

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@ -17,7 +17,7 @@
from tests import unittest
from twisted.internet import defer, reactor
from mock import Mock, call, ANY, NonCallableMock
from mock import Mock, call, ANY, NonCallableMock, patch
import json
from tests.utils import (
@ -59,7 +59,6 @@ class JustPresenceHandlers(object):
def __init__(self, hs):
self.presence_handler = PresenceHandler(hs)
class PresenceStateTestCase(unittest.TestCase):
""" Tests presence management. """
@ -78,6 +77,7 @@ class PresenceStateTestCase(unittest.TestCase):
resource_for_federation=Mock(),
http_client=None,
config=self.mock_config,
keyring=Mock(),
)
hs.handlers = JustPresenceHandlers(hs)
@ -230,6 +230,7 @@ class PresenceInvitesTestCase(unittest.TestCase):
resource_for_federation=self.mock_federation_resource,
http_client=self.mock_http_client,
config=self.mock_config,
keyring=Mock(),
)
hs.handlers = JustPresenceHandlers(hs)
@ -533,6 +534,7 @@ class PresencePushTestCase(unittest.TestCase):
resource_for_federation=self.mock_federation_resource,
http_client=self.mock_http_client,
config=self.mock_config,
keyring=Mock(),
)
hs.handlers = JustPresenceHandlers(hs)
@ -1026,6 +1028,7 @@ class PresencePollingTestCase(unittest.TestCase):
resource_for_federation=self.mock_federation_resource,
http_client=self.mock_http_client,
config=self.mock_config,
keyring=Mock(),
)
hs.handlers = JustPresenceHandlers(hs)

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@ -79,6 +79,7 @@ class TypingNotificationsTestCase(unittest.TestCase):
resource_for_federation=self.mock_federation_resource,
http_client=self.mock_http_client,
config=self.mock_config,
keyring=Mock(),
)
hs.handlers = JustTypingNotificationHandlers(hs)