diff options
Diffstat (limited to 'synapse/http')
| -rw-r--r-- | synapse/http/client.py | 46 | ||||
| -rw-r--r-- | synapse/http/federation/matrix_federation_agent.py | 16 | ||||
| -rw-r--r-- | synapse/http/matrixfederationclient.py | 26 |
3 files changed, 52 insertions, 36 deletions
diff --git a/synapse/http/client.py b/synapse/http/client.py index e5b13593f2..df7730078f 100644 --- a/synapse/http/client.py +++ b/synapse/http/client.py @@ -125,7 +125,7 @@ def _make_scheduler(reactor): return _scheduler -class IPBlacklistingResolver: +class _IPBlacklistingResolver: """ A proxy for reactor.nameResolver which only produces non-blacklisted IP addresses, preventing DNS rebinding attacks on URL preview. @@ -199,6 +199,35 @@ class IPBlacklistingResolver: return r +@implementer(IReactorPluggableNameResolver) +class BlacklistingReactorWrapper: + """ + A Reactor wrapper which will prevent DNS resolution to blacklisted IP + addresses, to prevent DNS rebinding. + """ + + def __init__( + self, + reactor: IReactorPluggableNameResolver, + ip_whitelist: Optional[IPSet], + ip_blacklist: IPSet, + ): + self._reactor = reactor + + # We need to use a DNS resolver which filters out blacklisted IP + # addresses, to prevent DNS rebinding. + self._nameResolver = _IPBlacklistingResolver( + self._reactor, ip_whitelist, ip_blacklist + ) + + def __getattr__(self, attr: str) -> Any: + # Passthrough to the real reactor except for the DNS resolver. + if attr == "nameResolver": + return self._nameResolver + else: + return getattr(self._reactor, attr) + + class BlacklistingAgentWrapper(Agent): """ An Agent wrapper which will prevent access to IP addresses being accessed @@ -292,22 +321,11 @@ class SimpleHttpClient: self.user_agent = self.user_agent.encode("ascii") if self._ip_blacklist: - real_reactor = hs.get_reactor() # If we have an IP blacklist, we need to use a DNS resolver which # filters out blacklisted IP addresses, to prevent DNS rebinding. - nameResolver = IPBlacklistingResolver( - real_reactor, self._ip_whitelist, self._ip_blacklist + self.reactor = BlacklistingReactorWrapper( + hs.get_reactor(), self._ip_whitelist, self._ip_blacklist ) - - @implementer(IReactorPluggableNameResolver) - class Reactor: - def __getattr__(_self, attr): - if attr == "nameResolver": - return nameResolver - else: - return getattr(real_reactor, attr) - - self.reactor = Reactor() else: self.reactor = hs.get_reactor() diff --git a/synapse/http/federation/matrix_federation_agent.py b/synapse/http/federation/matrix_federation_agent.py index e77f9587d0..3b756a7dc2 100644 --- a/synapse/http/federation/matrix_federation_agent.py +++ b/synapse/http/federation/matrix_federation_agent.py @@ -16,7 +16,7 @@ import logging import urllib.parse from typing import List, Optional -from netaddr import AddrFormatError, IPAddress +from netaddr import AddrFormatError, IPAddress, IPSet from zope.interface import implementer from twisted.internet import defer @@ -31,6 +31,7 @@ from twisted.web.http_headers import Headers from twisted.web.iweb import IAgent, IAgentEndpointFactory, IBodyProducer from synapse.crypto.context_factory import FederationPolicyForHTTPS +from synapse.http.client import BlacklistingAgentWrapper from synapse.http.federation.srv_resolver import Server, SrvResolver from synapse.http.federation.well_known_resolver import WellKnownResolver from synapse.logging.context import make_deferred_yieldable, run_in_background @@ -70,6 +71,7 @@ class MatrixFederationAgent: reactor: IReactorCore, tls_client_options_factory: Optional[FederationPolicyForHTTPS], user_agent: bytes, + ip_blacklist: IPSet, _srv_resolver: Optional[SrvResolver] = None, _well_known_resolver: Optional[WellKnownResolver] = None, ): @@ -90,12 +92,18 @@ class MatrixFederationAgent: self.user_agent = user_agent if _well_known_resolver is None: + # Note that the name resolver has already been wrapped in a + # IPBlacklistingResolver by MatrixFederationHttpClient. _well_known_resolver = WellKnownResolver( self._reactor, - agent=Agent( + agent=BlacklistingAgentWrapper( + Agent( + self._reactor, + pool=self._pool, + contextFactory=tls_client_options_factory, + ), self._reactor, - pool=self._pool, - contextFactory=tls_client_options_factory, + ip_blacklist=ip_blacklist, ), user_agent=self.user_agent, ) diff --git a/synapse/http/matrixfederationclient.py b/synapse/http/matrixfederationclient.py index 4e27f93b7a..c962994727 100644 --- a/synapse/http/matrixfederationclient.py +++ b/synapse/http/matrixfederationclient.py @@ -26,11 +26,10 @@ import treq from canonicaljson import encode_canonical_json from prometheus_client import Counter from signedjson.sign import sign_json -from zope.interface import implementer from twisted.internet import defer from twisted.internet.error import DNSLookupError -from twisted.internet.interfaces import IReactorPluggableNameResolver, IReactorTime +from twisted.internet.interfaces import IReactorTime from twisted.internet.task import _EPSILON, Cooperator from twisted.web.http_headers import Headers from twisted.web.iweb import IBodyProducer, IResponse @@ -45,7 +44,7 @@ from synapse.api.errors import ( from synapse.http import QuieterFileBodyProducer from synapse.http.client import ( BlacklistingAgentWrapper, - IPBlacklistingResolver, + BlacklistingReactorWrapper, encode_query_args, readBodyToFile, ) @@ -221,31 +220,22 @@ class MatrixFederationHttpClient: self.signing_key = hs.signing_key self.server_name = hs.hostname - real_reactor = hs.get_reactor() - # We need to use a DNS resolver which filters out blacklisted IP # addresses, to prevent DNS rebinding. - nameResolver = IPBlacklistingResolver( - real_reactor, None, hs.config.federation_ip_range_blacklist + self.reactor = BlacklistingReactorWrapper( + hs.get_reactor(), None, hs.config.federation_ip_range_blacklist ) - @implementer(IReactorPluggableNameResolver) - class Reactor: - def __getattr__(_self, attr): - if attr == "nameResolver": - return nameResolver - else: - return getattr(real_reactor, attr) - - self.reactor = Reactor() - user_agent = hs.version_string if hs.config.user_agent_suffix: user_agent = "%s %s" % (user_agent, hs.config.user_agent_suffix) user_agent = user_agent.encode("ascii") self.agent = MatrixFederationAgent( - self.reactor, tls_client_options_factory, user_agent + self.reactor, + tls_client_options_factory, + user_agent, + hs.config.federation_ip_range_blacklist, ) # Use a BlacklistingAgentWrapper to prevent circumventing the IP |