diff options
Diffstat (limited to 'synapse/crypto')
| -rw-r--r-- | synapse/crypto/context_factory.py | 39 | ||||
| -rw-r--r-- | synapse/crypto/event_signing.py | 109 | ||||
| -rw-r--r-- | synapse/crypto/keyclient.py | 147 | ||||
| -rw-r--r-- | synapse/crypto/keyring.py | 138 |
4 files changed, 108 insertions, 325 deletions
diff --git a/synapse/crypto/context_factory.py b/synapse/crypto/context_factory.py index 02b76dfcfb..49cbc7098f 100644 --- a/synapse/crypto/context_factory.py +++ b/synapse/crypto/context_factory.py @@ -1,4 +1,5 @@ # Copyright 2014-2016 OpenMarket Ltd +# Copyright 2019 New Vector Ltd # # Licensed under the Apache License, Version 2.0 (the "License"); # you may not use this file except in compliance with the License. @@ -11,12 +12,14 @@ # 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 zope.interface import implementer from OpenSSL import SSL, crypto from twisted.internet._sslverify import _defaultCurveName +from twisted.internet.abstract import isIPAddress, isIPv6Address from twisted.internet.interfaces import IOpenSSLClientConnectionCreator from twisted.internet.ssl import CertificateOptions, ContextFactory from twisted.python.failure import Failure @@ -42,12 +45,12 @@ class ServerContextFactory(ContextFactory): logger.exception("Failed to enable elliptic curve for TLS") context.set_options(SSL.OP_NO_SSLv2 | SSL.OP_NO_SSLv3) context.use_certificate_chain_file(config.tls_certificate_file) + context.use_privatekey(config.tls_private_key) - if not config.no_tls: - context.use_privatekey(config.tls_private_key) - - context.load_tmp_dh(config.tls_dh_params_path) - context.set_cipher_list("!ADH:HIGH+kEDH:!AECDH:HIGH+kEECDH") + # https://hynek.me/articles/hardening-your-web-servers-ssl-ciphers/ + context.set_cipher_list( + "ECDH+AESGCM:ECDH+CHACHA20:ECDH+AES256:ECDH+AES128:!aNULL:!SHA1" + ) def getContext(self): return self._context @@ -96,11 +99,15 @@ class ClientTLSOptions(object): def __init__(self, hostname, ctx): self._ctx = ctx - self._hostname = hostname - self._hostnameBytes = _idnaBytes(hostname) - ctx.set_info_callback( - _tolerateErrors(self._identityVerifyingInfoCallback) - ) + + if isIPAddress(hostname) or isIPv6Address(hostname): + self._hostnameBytes = hostname.encode('ascii') + self._sendSNI = False + else: + self._hostnameBytes = _idnaBytes(hostname) + self._sendSNI = True + + ctx.set_info_callback(_tolerateErrors(self._identityVerifyingInfoCallback)) def clientConnectionForTLS(self, tlsProtocol): context = self._ctx @@ -109,7 +116,9 @@ class ClientTLSOptions(object): return connection def _identityVerifyingInfoCallback(self, connection, where, ret): - if where & SSL.SSL_CB_HANDSHAKE_START: + # Literal IPv4 and IPv6 addresses are not permitted + # as host names according to the RFCs + if where & SSL.SSL_CB_HANDSHAKE_START and self._sendSNI: connection.set_tlsext_host_name(self._hostnameBytes) @@ -119,10 +128,8 @@ class ClientTLSOptionsFactory(object): def __init__(self, config): # We don't use config options yet - pass + self._options = CertificateOptions(verify=False) def get_options(self, host): - return ClientTLSOptions( - host, - CertificateOptions(verify=False).getContext() - ) + # Use _makeContext so that we get a fresh OpenSSL CTX each time. + return ClientTLSOptions(host, self._options._makeContext()) diff --git a/synapse/crypto/event_signing.py b/synapse/crypto/event_signing.py index 8774b28967..1dfa727fcf 100644 --- a/synapse/crypto/event_signing.py +++ b/synapse/crypto/event_signing.py @@ -23,14 +23,14 @@ from signedjson.sign import sign_json from unpaddedbase64 import decode_base64, encode_base64 from synapse.api.errors import Codes, SynapseError -from synapse.events.utils import prune_event +from synapse.events.utils import prune_event, prune_event_dict logger = logging.getLogger(__name__) def check_event_content_hash(event, hash_algorithm=hashlib.sha256): """Check whether the hash for this PDU matches the contents""" - name, expected_hash = compute_content_hash(event, hash_algorithm) + name, expected_hash = compute_content_hash(event.get_pdu_json(), hash_algorithm) logger.debug("Expecting hash: %s", encode_base64(expected_hash)) # some malformed events lack a 'hashes'. Protect against it being missing @@ -59,35 +59,70 @@ def check_event_content_hash(event, hash_algorithm=hashlib.sha256): return message_hash_bytes == expected_hash -def compute_content_hash(event, hash_algorithm): - event_json = event.get_pdu_json() - event_json.pop("age_ts", None) - event_json.pop("unsigned", None) - event_json.pop("signatures", None) - event_json.pop("hashes", None) - event_json.pop("outlier", None) - event_json.pop("destinations", None) +def compute_content_hash(event_dict, hash_algorithm): + """Compute the content hash of an event, which is the hash of the + unredacted event. - event_json_bytes = encode_canonical_json(event_json) + Args: + event_dict (dict): The unredacted event as a dict + hash_algorithm: A hasher from `hashlib`, e.g. hashlib.sha256, to use + to hash the event + + Returns: + tuple[str, bytes]: A tuple of the name of hash and the hash as raw + bytes. + """ + event_dict = dict(event_dict) + event_dict.pop("age_ts", None) + event_dict.pop("unsigned", None) + event_dict.pop("signatures", None) + event_dict.pop("hashes", None) + event_dict.pop("outlier", None) + event_dict.pop("destinations", None) + + event_json_bytes = encode_canonical_json(event_dict) hashed = hash_algorithm(event_json_bytes) return (hashed.name, hashed.digest()) def compute_event_reference_hash(event, hash_algorithm=hashlib.sha256): + """Computes the event reference hash. This is the hash of the redacted + event. + + Args: + event (FrozenEvent) + hash_algorithm: A hasher from `hashlib`, e.g. hashlib.sha256, to use + to hash the event + + Returns: + tuple[str, bytes]: A tuple of the name of hash and the hash as raw + bytes. + """ tmp_event = prune_event(event) - event_json = tmp_event.get_pdu_json() - event_json.pop("signatures", None) - event_json.pop("age_ts", None) - event_json.pop("unsigned", None) - event_json_bytes = encode_canonical_json(event_json) + event_dict = tmp_event.get_pdu_json() + event_dict.pop("signatures", None) + event_dict.pop("age_ts", None) + event_dict.pop("unsigned", None) + event_json_bytes = encode_canonical_json(event_dict) hashed = hash_algorithm(event_json_bytes) return (hashed.name, hashed.digest()) -def compute_event_signature(event, signature_name, signing_key): - tmp_event = prune_event(event) - redact_json = tmp_event.get_pdu_json() +def compute_event_signature(event_dict, signature_name, signing_key): + """Compute the signature of the event for the given name and key. + + Args: + event_dict (dict): The event as a dict + signature_name (str): The name of the entity signing the event + (typically the server's hostname). + signing_key (syutil.crypto.SigningKey): The key to sign with + + Returns: + dict[str, dict[str, str]]: Returns a dictionary in the same format of + an event's signatures field. + """ + redact_json = prune_event_dict(event_dict) redact_json.pop("age_ts", None) redact_json.pop("unsigned", None) logger.debug("Signing event: %s", encode_canonical_json(redact_json)) @@ -96,25 +131,25 @@ def compute_event_signature(event, signature_name, signing_key): return redact_json["signatures"] -def add_hashes_and_signatures(event, signature_name, signing_key, +def add_hashes_and_signatures(event_dict, signature_name, signing_key, hash_algorithm=hashlib.sha256): - # if hasattr(event, "old_state_events"): - # state_json_bytes = encode_canonical_json( - # [e.event_id for e in event.old_state_events.values()] - # ) - # hashed = hash_algorithm(state_json_bytes) - # event.state_hash = { - # hashed.name: encode_base64(hashed.digest()) - # } - - name, digest = compute_content_hash(event, hash_algorithm=hash_algorithm) - - if not hasattr(event, "hashes"): - event.hashes = {} - event.hashes[name] = encode_base64(digest) - - event.signatures = compute_event_signature( - event, + """Add content hash and sign the event + + Args: + event_dict (dict): The event to add hashes to and sign + signature_name (str): The name of the entity signing the event + (typically the server's hostname). + signing_key (syutil.crypto.SigningKey): The key to sign with + hash_algorithm: A hasher from `hashlib`, e.g. hashlib.sha256, to use + to hash the event + """ + + name, digest = compute_content_hash(event_dict, hash_algorithm=hash_algorithm) + + event_dict.setdefault("hashes", {})[name] = encode_base64(digest) + + event_dict["signatures"] = compute_event_signature( + event_dict, signature_name=signature_name, signing_key=signing_key, ) diff --git a/synapse/crypto/keyclient.py b/synapse/crypto/keyclient.py deleted file mode 100644 index 080c81f14b..0000000000 --- a/synapse/crypto/keyclient.py +++ /dev/null @@ -1,147 +0,0 @@ -# -*- 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 canonicaljson import json - -from twisted.internet import defer, reactor -from twisted.internet.error import ConnectError -from twisted.internet.protocol import Factory -from twisted.names.error import DomainError -from twisted.web.http import HTTPClient - -from synapse.http.endpoint import matrix_federation_endpoint -from synapse.util import logcontext - -logger = logging.getLogger(__name__) - -KEY_API_V1 = b"/_matrix/key/v1/" - - -@defer.inlineCallbacks -def fetch_server_key(server_name, tls_client_options_factory, path=KEY_API_V1): - """Fetch the keys for a remote server.""" - - factory = SynapseKeyClientFactory() - factory.path = path - factory.host = server_name - endpoint = matrix_federation_endpoint( - reactor, server_name, tls_client_options_factory, timeout=30 - ) - - for i in range(5): - try: - with logcontext.PreserveLoggingContext(): - protocol = yield endpoint.connect(factory) - server_response, server_certificate = yield protocol.remote_key - defer.returnValue((server_response, server_certificate)) - except SynapseKeyClientError as e: - logger.warn("Error getting key for %r: %s", server_name, e) - if e.status.startswith(b"4"): - # Don't retry for 4xx responses. - raise IOError("Cannot get key for %r" % server_name) - except (ConnectError, DomainError) as e: - logger.warn("Error getting key for %r: %s", server_name, e) - except Exception: - logger.exception("Error getting key for %r", server_name) - raise IOError("Cannot get key for %r" % server_name) - - -class SynapseKeyClientError(Exception): - """The key wasn't retrieved from the remote server.""" - status = None - pass - - -class SynapseKeyClientProtocol(HTTPClient): - """Low level HTTPS client which retrieves an application/json response from - 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() - self.host = None - self._peer = None - - def connectionMade(self): - self._peer = self.transport.getPeer() - logger.debug("Connected to %s", self._peer) - - if not isinstance(self.path, bytes): - self.path = self.path.encode('ascii') - - if not isinstance(self.host, bytes): - self.host = self.host.encode('ascii') - - self.sendCommand(b"GET", self.path) - if self.host: - self.sendHeader(b"Host", self.host) - self.endHeaders() - self.timer = reactor.callLater( - self.timeout, - self.on_timeout - ) - - def errback(self, error): - if not self.remote_key.called: - self.remote_key.errback(error) - - def callback(self, result): - if not self.remote_key.called: - self.remote_key.callback(result) - - def handleStatus(self, version, status, message): - if status != b"200": - # logger.info("Non-200 response from %s: %s %s", - # self.transport.getHost(), status, message) - error = SynapseKeyClientError( - "Non-200 response %r from %r" % (status, self.host) - ) - error.status = status - self.errback(error) - 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()) - self.transport.abortConnection() - return - - certificate = self.transport.getPeerCertificate() - self.callback((json_response, certificate)) - self.transport.abortConnection() - self.timer.cancel() - - def on_timeout(self): - logger.debug( - "Timeout waiting for response from %s: %s", - self.host, self._peer, - ) - self.errback(IOError("Timeout waiting for response")) - self.transport.abortConnection() - - -class SynapseKeyClientFactory(Factory): - def protocol(self): - protocol = SynapseKeyClientProtocol() - protocol.path = self.path - protocol.host = self.host - return protocol diff --git a/synapse/crypto/keyring.py b/synapse/crypto/keyring.py index d89f94c219..cce40fdd2d 100644 --- a/synapse/crypto/keyring.py +++ b/synapse/crypto/keyring.py @@ -1,6 +1,6 @@ # -*- coding: utf-8 -*- # Copyright 2014-2016 OpenMarket Ltd -# Copyright 2017 New Vector Ltd. +# Copyright 2017, 2018 New Vector Ltd. # # Licensed under the Apache License, Version 2.0 (the "License"); # you may not use this file except in compliance with the License. @@ -14,7 +14,6 @@ # See the License for the specific language governing permissions and # limitations under the License. -import hashlib import logging from collections import namedtuple @@ -32,13 +31,11 @@ from signedjson.sign import ( signature_ids, verify_signed_json, ) -from unpaddedbase64 import decode_base64, encode_base64 +from unpaddedbase64 import decode_base64 -from OpenSSL import crypto from twisted.internet import defer -from synapse.api.errors import Codes, SynapseError -from synapse.crypto.keyclient import fetch_server_key +from synapse.api.errors import Codes, RequestSendFailed, SynapseError from synapse.util import logcontext, unwrapFirstError from synapse.util.logcontext import ( LoggingContext, @@ -395,32 +392,13 @@ class Keyring(object): @defer.inlineCallbacks def get_keys_from_server(self, server_name_and_key_ids): - @defer.inlineCallbacks - def get_key(server_name, key_ids): - keys = None - try: - keys = yield self.get_server_verify_key_v2_direct( - server_name, key_ids - ) - except Exception as e: - logger.info( - "Unable to get key %r for %r directly: %s %s", - key_ids, server_name, - type(e).__name__, str(e), - ) - - if not keys: - keys = yield self.get_server_verify_key_v1_direct( - server_name, key_ids - ) - - keys = {server_name: keys} - - defer.returnValue(keys) - results = yield logcontext.make_deferred_yieldable(defer.gatherResults( [ - run_in_background(get_key, server_name, key_ids) + run_in_background( + self.get_server_verify_key_v2_direct, + server_name, + key_ids, + ) for server_name, key_ids in server_name_and_key_ids ], consumeErrors=True, @@ -524,34 +502,16 @@ class Keyring(object): if requested_key_id in keys: continue - (response, tls_certificate) = yield fetch_server_key( - server_name, self.hs.tls_client_options_factory, - path=("/_matrix/key/v2/server/%s" % ( - urllib.parse.quote(requested_key_id), - )).encode("ascii"), + response = yield self.client.get_json( + destination=server_name, + path="/_matrix/key/v2/server/" + urllib.parse.quote(requested_key_id), + ignore_backoff=True, ) if (u"signatures" not in response or server_name not in response[u"signatures"]): raise KeyLookupError("Key response not signed by remote server") - if "tls_fingerprints" not in response: - raise KeyLookupError("Key response missing TLS fingerprints") - - certificate_bytes = crypto.dump_certificate( - crypto.FILETYPE_ASN1, tls_certificate - ) - sha256_fingerprint = hashlib.sha256(certificate_bytes).digest() - sha256_fingerprint_b64 = encode_base64(sha256_fingerprint) - - response_sha256_fingerprints = set() - for fingerprint in response[u"tls_fingerprints"]: - if u"sha256" in fingerprint: - response_sha256_fingerprints.add(fingerprint[u"sha256"]) - - if sha256_fingerprint_b64 not in response_sha256_fingerprints: - raise KeyLookupError("TLS certificate not allowed by fingerprints") - response_keys = yield self.process_v2_response( from_server=server_name, requested_ids=[requested_key_id], @@ -657,78 +617,6 @@ class Keyring(object): defer.returnValue(results) - @defer.inlineCallbacks - def get_server_verify_key_v1_direct(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. - """ - - # Try to fetch the key from the remote server. - - (response, tls_certificate) = yield fetch_server_key( - server_name, self.hs.tls_client_options_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 KeyLookupError("Key response not signed by remote server") - - if "tls_certificate" not in response: - raise KeyLookupError("Key response missing TLS certificate") - - tls_certificate_b64 = response["tls_certificate"] - - if encode_base64(x509_certificate_bytes) != tls_certificate_b64: - raise KeyLookupError("TLS certificate doesn't match") - - # Cache the result in the datastore. - - time_now_ms = self.clock.time_msec() - - 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_key.time_added = time_now_ms - verify_keys[key_id] = verify_key - - for key_id in response["signatures"][server_name]: - if key_id not in response["verify_keys"]: - raise KeyLookupError( - "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] - ) - - yield self.store.store_server_certificate( - server_name, - server_name, - time_now_ms, - tls_certificate, - ) - - yield self.store_keys( - server_name=server_name, - from_server=server_name, - verify_keys=verify_keys, - ) - - defer.returnValue(verify_keys) - def store_keys(self, server_name, from_server, verify_keys): """Store a collection of verify keys for a given server Args: @@ -768,7 +656,7 @@ def _handle_key_deferred(verify_request): try: with PreserveLoggingContext(): _, key_id, verify_key = yield verify_request.deferred - except IOError as e: + except (IOError, RequestSendFailed) as e: logger.warn( "Got IOError when downloading keys for %s: %s %s", server_name, type(e).__name__, str(e), |