Fix logcontexts in _check_sigs_and_hashes

This commit is contained in:
Richard van der Hoff 2017-09-20 01:32:42 +01:00
parent 72472456d8
commit 6de74ea6d7
2 changed files with 59 additions and 57 deletions

View file

@ -18,8 +18,7 @@ from synapse.api.errors import SynapseError
from synapse.crypto.event_signing import check_event_content_hash
from synapse.events import spamcheck
from synapse.events.utils import prune_event
from synapse.util import unwrapFirstError
from synapse.util.logcontext import preserve_context_over_deferred
from synapse.util import unwrapFirstError, logcontext
from twisted.internet import defer
logger = logging.getLogger(__name__)
@ -51,56 +50,52 @@ class FederationBase(object):
"""
deferreds = self._check_sigs_and_hashes(pdus)
def callback(pdu):
return pdu
@defer.inlineCallbacks
def handle_check_result(pdu, deferred):
try:
res = yield logcontext.make_deferred_yieldable(deferred)
except SynapseError:
res = None
def errback(failure, pdu):
failure.trap(SynapseError)
return None
def try_local_db(res, pdu):
if not res:
# Check local db.
return self.store.get_event(
res = yield self.store.get_event(
pdu.event_id,
allow_rejected=True,
allow_none=True,
)
return res
def try_remote(res, pdu):
if not res and pdu.origin != origin:
return self.get_pdu(
destinations=[pdu.origin],
event_id=pdu.event_id,
outlier=outlier,
timeout=10000,
).addErrback(lambda e: None)
return res
try:
res = yield self.get_pdu(
destinations=[pdu.origin],
event_id=pdu.event_id,
outlier=outlier,
timeout=10000,
)
except SynapseError:
pass
def warn(res, pdu):
if not res:
logger.warn(
"Failed to find copy of %s with valid signature",
pdu.event_id,
)
return res
for pdu, deferred in zip(pdus, deferreds):
deferred.addCallbacks(
callback, errback, errbackArgs=[pdu]
).addCallback(
try_local_db, pdu
).addCallback(
try_remote, pdu
).addCallback(
warn, pdu
defer.returnValue(res)
handle = logcontext.preserve_fn(handle_check_result)
deferreds2 = [
handle(pdu, deferred)
for pdu, deferred in zip(pdus, deferreds)
]
valid_pdus = yield logcontext.make_deferred_yieldable(
defer.gatherResults(
deferreds2,
consumeErrors=True,
)
valid_pdus = yield preserve_context_over_deferred(defer.gatherResults(
deferreds,
consumeErrors=True
)).addErrback(unwrapFirstError)
).addErrback(unwrapFirstError)
if include_none:
defer.returnValue(valid_pdus)
@ -108,7 +103,9 @@ class FederationBase(object):
defer.returnValue([p for p in valid_pdus if p])
def _check_sigs_and_hash(self, pdu):
return self._check_sigs_and_hashes([pdu])[0]
return logcontext.make_deferred_yieldable(
self._check_sigs_and_hashes([pdu])[0],
)
def _check_sigs_and_hashes(self, pdus):
"""Checks that each of the received events is correctly signed by the
@ -123,6 +120,7 @@ class FederationBase(object):
* returns a redacted version of the event (if the signature
matched but the hash did not)
* throws a SynapseError if the signature check failed.
The deferreds run their callbacks in the sentinel logcontext.
"""
redacted_pdus = [
@ -135,29 +133,33 @@ class FederationBase(object):
for p in redacted_pdus
])
ctx = logcontext.LoggingContext.current_context()
def callback(_, pdu, redacted):
if not check_event_content_hash(pdu):
logger.warn(
"Event content has been tampered, redacting %s: %s",
pdu.event_id, pdu.get_pdu_json()
)
return redacted
with logcontext.PreserveLoggingContext(ctx):
if not check_event_content_hash(pdu):
logger.warn(
"Event content has been tampered, redacting %s: %s",
pdu.event_id, pdu.get_pdu_json()
)
return redacted
if spamcheck.check_event_for_spam(pdu):
logger.warn(
"Event contains spam, redacting %s: %s",
pdu.event_id, pdu.get_pdu_json()
)
return redacted
if spamcheck.check_event_for_spam(pdu):
logger.warn(
"Event contains spam, redacting %s: %s",
pdu.event_id, pdu.get_pdu_json()
)
return redacted
return pdu
return pdu
def errback(failure, pdu):
failure.trap(SynapseError)
logger.warn(
"Signature check failed for %s",
pdu.event_id,
)
with logcontext.PreserveLoggingContext(ctx):
logger.warn(
"Signature check failed for %s",
pdu.event_id,
)
return failure
for deferred, pdu, redacted in zip(deferreds, pdus, redacted_pdus):

View file

@ -22,7 +22,7 @@ from synapse.api.constants import Membership
from synapse.api.errors import (
CodeMessageException, HttpResponseException, SynapseError,
)
from synapse.util import unwrapFirstError
from synapse.util import unwrapFirstError, logcontext
from synapse.util.caches.expiringcache import ExpiringCache
from synapse.util.logutils import log_function
from synapse.util.logcontext import preserve_fn, preserve_context_over_deferred
@ -189,10 +189,10 @@ class FederationClient(FederationBase):
]
# FIXME: We should handle signature failures more gracefully.
pdus[:] = yield preserve_context_over_deferred(defer.gatherResults(
pdus[:] = yield logcontext.make_deferred_yieldable(defer.gatherResults(
self._check_sigs_and_hashes(pdus),
consumeErrors=True,
)).addErrback(unwrapFirstError)
).addErrback(unwrapFirstError))
defer.returnValue(pdus)
@ -252,7 +252,7 @@ class FederationClient(FederationBase):
pdu = pdu_list[0]
# Check signatures are correct.
signed_pdu = yield self._check_sigs_and_hashes([pdu])[0]
signed_pdu = yield self._check_sigs_and_hash(pdu)
break