diff --git a/changelog.d/8104.bugfix b/changelog.d/8104.bugfix
new file mode 100644
index 0000000000..e32e2996c4
--- /dev/null
+++ b/changelog.d/8104.bugfix
@@ -0,0 +1 @@
+Fix a bug introduced in v1.7.2 impacting message retention policies that would allow federated homeservers to dictate a retention period that's lower than the configured minimum allowed duration in the configuration file.
diff --git a/docs/sample_config.yaml b/docs/sample_config.yaml
index f168853f67..3528d9e11f 100644
--- a/docs/sample_config.yaml
+++ b/docs/sample_config.yaml
@@ -378,11 +378,10 @@ retention:
# min_lifetime: 1d
# max_lifetime: 1y
- # Retention policy limits. If set, a user won't be able to send a
- # 'm.room.retention' event which features a 'min_lifetime' or a 'max_lifetime'
- # that's not within this range. This is especially useful in closed federations,
- # in which server admins can make sure every federating server applies the same
- # rules.
+ # Retention policy limits. If set, and the state of a room contains a
+ # 'm.room.retention' event in its state which contains a 'min_lifetime' or a
+ # 'max_lifetime' that's out of these bounds, Synapse will cap the room's policy
+ # to these limits when running purge jobs.
#
#allowed_lifetime_min: 1d
#allowed_lifetime_max: 1y
@@ -408,12 +407,19 @@ retention:
# (e.g. every 12h), but not want that purge to be performed by a job that's
# iterating over every room it knows, which could be heavy on the server.
#
+ # If any purge job is configured, it is strongly recommended to have at least
+ # a single job with neither 'shortest_max_lifetime' nor 'longest_max_lifetime'
+ # set, or one job without 'shortest_max_lifetime' and one job without
+ # 'longest_max_lifetime' set. Otherwise some rooms might be ignored, even if
+ # 'allowed_lifetime_min' and 'allowed_lifetime_max' are set, because capping a
+ # room's policy to these values is done after the policies are retrieved from
+ # Synapse's database (which is done using the range specified in a purge job's
+ # configuration).
+ #
#purge_jobs:
- # - shortest_max_lifetime: 1d
- # longest_max_lifetime: 3d
+ # - longest_max_lifetime: 3d
# interval: 12h
# - shortest_max_lifetime: 3d
- # longest_max_lifetime: 1y
# interval: 1d
# Inhibits the /requestToken endpoints from returning an error that might leak
diff --git a/synapse/config/server.py b/synapse/config/server.py
index ed66f3eba1..526a90b26a 100644
--- a/synapse/config/server.py
+++ b/synapse/config/server.py
@@ -961,11 +961,10 @@ class ServerConfig(Config):
# min_lifetime: 1d
# max_lifetime: 1y
- # Retention policy limits. If set, a user won't be able to send a
- # 'm.room.retention' event which features a 'min_lifetime' or a 'max_lifetime'
- # that's not within this range. This is especially useful in closed federations,
- # in which server admins can make sure every federating server applies the same
- # rules.
+ # Retention policy limits. If set, and the state of a room contains a
+ # 'm.room.retention' event in its state which contains a 'min_lifetime' or a
+ # 'max_lifetime' that's out of these bounds, Synapse will cap the room's policy
+ # to these limits when running purge jobs.
#
#allowed_lifetime_min: 1d
#allowed_lifetime_max: 1y
@@ -991,12 +990,19 @@ class ServerConfig(Config):
# (e.g. every 12h), but not want that purge to be performed by a job that's
# iterating over every room it knows, which could be heavy on the server.
#
+ # If any purge job is configured, it is strongly recommended to have at least
+ # a single job with neither 'shortest_max_lifetime' nor 'longest_max_lifetime'
+ # set, or one job without 'shortest_max_lifetime' and one job without
+ # 'longest_max_lifetime' set. Otherwise some rooms might be ignored, even if
+ # 'allowed_lifetime_min' and 'allowed_lifetime_max' are set, because capping a
+ # room's policy to these values is done after the policies are retrieved from
+ # Synapse's database (which is done using the range specified in a purge job's
+ # configuration).
+ #
#purge_jobs:
- # - shortest_max_lifetime: 1d
- # longest_max_lifetime: 3d
+ # - longest_max_lifetime: 3d
# interval: 12h
# - shortest_max_lifetime: 3d
- # longest_max_lifetime: 1y
# interval: 1d
# Inhibits the /requestToken endpoints from returning an error that might leak
diff --git a/synapse/events/validator.py b/synapse/events/validator.py
index 588d222f36..5ce3874fba 100644
--- a/synapse/events/validator.py
+++ b/synapse/events/validator.py
@@ -74,15 +74,14 @@ class EventValidator(object):
)
if event.type == EventTypes.Retention:
- self._validate_retention(event, config)
+ self._validate_retention(event)
- def _validate_retention(self, event, config):
+ def _validate_retention(self, event):
"""Checks that an event that defines the retention policy for a room respects the
- boundaries imposed by the server's administrator.
+ format enforced by the spec.
Args:
event (FrozenEvent): The event to validate.
- config (Config): The homeserver's configuration.
"""
min_lifetime = event.content.get("min_lifetime")
max_lifetime = event.content.get("max_lifetime")
@@ -95,32 +94,6 @@ class EventValidator(object):
errcode=Codes.BAD_JSON,
)
- if (
- config.retention_allowed_lifetime_min is not None
- and min_lifetime < config.retention_allowed_lifetime_min
- ):
- raise SynapseError(
- code=400,
- msg=(
- "'min_lifetime' can't be lower than the minimum allowed"
- " value enforced by the server's administrator"
- ),
- errcode=Codes.BAD_JSON,
- )
-
- if (
- config.retention_allowed_lifetime_max is not None
- and min_lifetime > config.retention_allowed_lifetime_max
- ):
- raise SynapseError(
- code=400,
- msg=(
- "'min_lifetime' can't be greater than the maximum allowed"
- " value enforced by the server's administrator"
- ),
- errcode=Codes.BAD_JSON,
- )
-
if max_lifetime is not None:
if not isinstance(max_lifetime, int):
raise SynapseError(
@@ -129,32 +102,6 @@ class EventValidator(object):
errcode=Codes.BAD_JSON,
)
- if (
- config.retention_allowed_lifetime_min is not None
- and max_lifetime < config.retention_allowed_lifetime_min
- ):
- raise SynapseError(
- code=400,
- msg=(
- "'max_lifetime' can't be lower than the minimum allowed value"
- " enforced by the server's administrator"
- ),
- errcode=Codes.BAD_JSON,
- )
-
- if (
- config.retention_allowed_lifetime_max is not None
- and max_lifetime > config.retention_allowed_lifetime_max
- ):
- raise SynapseError(
- code=400,
- msg=(
- "'max_lifetime' can't be greater than the maximum allowed"
- " value enforced by the server's administrator"
- ),
- errcode=Codes.BAD_JSON,
- )
-
if (
min_lifetime is not None
and max_lifetime is not None
diff --git a/synapse/handlers/pagination.py b/synapse/handlers/pagination.py
index 487420bb5d..ac3418d69d 100644
--- a/synapse/handlers/pagination.py
+++ b/synapse/handlers/pagination.py
@@ -82,6 +82,9 @@ class PaginationHandler(object):
self._retention_default_max_lifetime = hs.config.retention_default_max_lifetime
+ self._retention_allowed_lifetime_min = hs.config.retention_allowed_lifetime_min
+ self._retention_allowed_lifetime_max = hs.config.retention_allowed_lifetime_max
+
if hs.config.retention_enabled:
# Run the purge jobs described in the configuration file.
for job in hs.config.retention_purge_jobs:
@@ -111,7 +114,7 @@ class PaginationHandler(object):
the range to handle (inclusive). If None, it means that the range has no
upper limit.
"""
- # We want the storage layer to to include rooms with no retention policy in its
+ # We want the storage layer to include rooms with no retention policy in its
# return value only if a default retention policy is defined in the server's
# configuration and that policy's 'max_lifetime' is either lower (or equal) than
# max_ms or higher than min_ms (or both).
@@ -152,13 +155,32 @@ class PaginationHandler(object):
)
continue
- max_lifetime = retention_policy["max_lifetime"]
+ # If max_lifetime is None, it means that the room has no retention policy.
+ # Given we only retrieve such rooms when there's a default retention policy
+ # defined in the server's configuration, we can safely assume that's the
+ # case and use it for this room.
+ max_lifetime = (
+ retention_policy["max_lifetime"] or self._retention_default_max_lifetime
+ )
- if max_lifetime is None:
- # If max_lifetime is None, it means that include_null equals True,
- # therefore we can safely assume that there is a default policy defined
- # in the server's configuration.
- max_lifetime = self._retention_default_max_lifetime
+ # Cap the effective max_lifetime to be within the range allowed in the
+ # config.
+ # We do this in two steps:
+ # 1. Make sure it's higher or equal to the minimum allowed value, and if
+ # it's not replace it with that value. This is because the server
+ # operator can be required to not delete information before a given
+ # time, e.g. to comply with freedom of information laws.
+ # 2. Make sure the resulting value is lower or equal to the maximum allowed
+ # value, and if it's not replace it with that value. This is because the
+ # server operator can be required to delete any data after a specific
+ # amount of time.
+ if self._retention_allowed_lifetime_min is not None:
+ max_lifetime = max(self._retention_allowed_lifetime_min, max_lifetime)
+
+ if self._retention_allowed_lifetime_max is not None:
+ max_lifetime = min(max_lifetime, self._retention_allowed_lifetime_max)
+
+ logger.debug("[purge] max_lifetime for room %s: %s", room_id, max_lifetime)
# Figure out what token we should start purging at.
ts = self.clock.time_msec() - max_lifetime
diff --git a/tests/rest/client/test_retention.py b/tests/rest/client/test_retention.py
index 0b191d13c6..d4e7fa1293 100644
--- a/tests/rest/client/test_retention.py
+++ b/tests/rest/client/test_retention.py
@@ -45,50 +45,63 @@ class RetentionTestCase(unittest.HomeserverTestCase):
}
self.hs = self.setup_test_homeserver(config=config)
+
return self.hs
def prepare(self, reactor, clock, homeserver):
self.user_id = self.register_user("user", "password")
self.token = self.login("user", "password")
- def test_retention_state_event(self):
- """Tests that the server configuration can limit the values a user can set to the
- room's retention policy.
+ self.store = self.hs.get_datastore()
+ self.serializer = self.hs.get_event_client_serializer()
+ self.clock = self.hs.get_clock()
+
+ def test_retention_event_purged_with_state_event(self):
+ """Tests that expired events are correctly purged when the room's retention policy
+ is defined by a state event.
"""
room_id = self.helper.create_room_as(self.user_id, tok=self.token)
+ # Set the room's retention period to 2 days.
+ lifetime = one_day_ms * 2
self.helper.send_state(
room_id=room_id,
event_type=EventTypes.Retention,
- body={"max_lifetime": one_day_ms * 4},
+ body={"max_lifetime": lifetime},
tok=self.token,
- expect_code=400,
)
+ self._test_retention_event_purged(room_id, one_day_ms * 1.5)
+
+ def test_retention_event_purged_with_state_event_outside_allowed(self):
+ """Tests that the server configuration can override the policy for a room when
+ running the purge jobs.
+ """
+ room_id = self.helper.create_room_as(self.user_id, tok=self.token)
+
+ # Set a max_lifetime higher than the maximum allowed value.
self.helper.send_state(
room_id=room_id,
event_type=EventTypes.Retention,
- body={"max_lifetime": one_hour_ms},
+ body={"max_lifetime": one_day_ms * 4},
tok=self.token,
- expect_code=400,
)
- def test_retention_event_purged_with_state_event(self):
- """Tests that expired events are correctly purged when the room's retention policy
- is defined by a state event.
- """
- room_id = self.helper.create_room_as(self.user_id, tok=self.token)
+ # Check that the event is purged after waiting for the maximum allowed duration
+ # instead of the one specified in the room's policy.
+ self._test_retention_event_purged(room_id, one_day_ms * 1.5)
- # Set the room's retention period to 2 days.
- lifetime = one_day_ms * 2
+ # Set a max_lifetime lower than the minimum allowed value.
self.helper.send_state(
room_id=room_id,
event_type=EventTypes.Retention,
- body={"max_lifetime": lifetime},
+ body={"max_lifetime": one_hour_ms},
tok=self.token,
)
- self._test_retention_event_purged(room_id, one_day_ms * 1.5)
+ # Check that the event is purged after waiting for the minimum allowed duration
+ # instead of the one specified in the room's policy.
+ self._test_retention_event_purged(room_id, one_day_ms * 0.5)
def test_retention_event_purged_without_state_event(self):
"""Tests that expired events are correctly purged when the room's retention policy
@@ -140,7 +153,27 @@ class RetentionTestCase(unittest.HomeserverTestCase):
# That event should be the second, not outdated event.
self.assertEqual(filtered_events[0].event_id, valid_event_id, filtered_events)
- def _test_retention_event_purged(self, room_id, increment):
+ def _test_retention_event_purged(self, room_id: str, increment: float):
+ """Run the following test scenario to test the message retention policy support:
+
+ 1. Send event 1
+ 2. Increment time by `increment`
+ 3. Send event 2
+ 4. Increment time by `increment`
+ 5. Check that event 1 has been purged
+ 6. Check that event 2 has not been purged
+ 7. Check that state events that were sent before event 1 aren't purged.
+ The main reason for sending a second event is because currently Synapse won't
+ purge the latest message in a room because it would otherwise result in a lack of
+ forward extremities for this room. It's also a good thing to ensure the purge jobs
+ aren't too greedy and purge messages they shouldn't.
+
+ Args:
+ room_id: The ID of the room to test retention in.
+ increment: The number of milliseconds to advance the clock each time. Must be
+ defined so that events in the room aren't purged if they are `increment`
+ old but are purged if they are `increment * 2` old.
+ """
# Get the create event to, later, check that we can still access it.
message_handler = self.hs.get_message_handler()
create_event = self.get_success(
@@ -156,7 +189,7 @@ class RetentionTestCase(unittest.HomeserverTestCase):
expired_event_id = resp.get("event_id")
# Check that we can retrieve the event.
- expired_event = self.get_event(room_id, expired_event_id)
+ expired_event = self.get_event(expired_event_id)
self.assertEqual(
expired_event.get("content", {}).get("body"), "1", expired_event
)
@@ -174,26 +207,31 @@ class RetentionTestCase(unittest.HomeserverTestCase):
# one should still be kept.
self.reactor.advance(increment / 1000)
- # Check that the event has been purged from the database.
- self.get_event(room_id, expired_event_id, expected_code=404)
+ # Check that the first event has been purged from the database, i.e. that we
+ # can't retrieve it anymore, because it has expired.
+ self.get_event(expired_event_id, expect_none=True)
- # Check that the event that hasn't been purged can still be retrieved.
- valid_event = self.get_event(room_id, valid_event_id)
+ # Check that the event that hasn't expired can still be retrieved.
+ valid_event = self.get_event(valid_event_id)
self.assertEqual(valid_event.get("content", {}).get("body"), "2", valid_event)
# Check that we can still access state events that were sent before the event that
# has been purged.
self.get_event(room_id, create_event.event_id)
- def get_event(self, room_id, event_id, expected_code=200):
- url = "/_matrix/client/r0/rooms/%s/event/%s" % (room_id, event_id)
+ def get_event(self, event_id, expect_none=False):
+ event = self.get_success(self.store.get_event(event_id, allow_none=True))
- request, channel = self.make_request("GET", url, access_token=self.token)
- self.render(request)
+ if expect_none:
+ self.assertIsNone(event)
+ return {}
- self.assertEqual(channel.code, expected_code, channel.result)
+ self.assertIsNotNone(event)
- return channel.json_body
+ time_now = self.clock.time_msec()
+ serialized = self.get_success(self.serializer.serialize_event(event, time_now))
+
+ return serialized
class RetentionNoDefaultPolicyTestCase(unittest.HomeserverTestCase):
|
