POC delete stale non-e2e devices for users (#14038)

This should help reduce the number of devices e.g. simple bots the repeatedly login rack up.

We only delete non-e2e devices as they should be safe to delete, whereas if we delete e2e devices for a user we may accidentally break their ability to receive e2e keys for a message.

Co-authored-by: Patrick Cloke <clokep@users.noreply.github.com>
Co-authored-by: Sean Quah <8349537+squahtx@users.noreply.github.com>
This commit is contained in:
Erik Johnston 2022-11-29 10:36:41 +00:00 committed by GitHub
parent 72f3e38137
commit c7e29ca277
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5 changed files with 83 additions and 4 deletions

1
changelog.d/14038.misc Normal file
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@ -0,0 +1 @@
Prune user's old devices on login if they have too many.

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@ -421,6 +421,9 @@ class DeviceHandler(DeviceWorkerHandler):
self._check_device_name_length(initial_device_display_name)
# Prune the user's device list if they already have a lot of devices.
await self._prune_too_many_devices(user_id)
if device_id is not None:
new_device = await self.store.store_device(
user_id=user_id,
@ -452,6 +455,14 @@ class DeviceHandler(DeviceWorkerHandler):
raise errors.StoreError(500, "Couldn't generate a device ID.")
async def _prune_too_many_devices(self, user_id: str) -> None:
"""Delete any excess old devices this user may have."""
device_ids = await self.store.check_too_many_devices_for_user(user_id)
if not device_ids:
return
await self.delete_devices(user_id, device_ids)
async def _delete_stale_devices(self) -> None:
"""Background task that deletes devices which haven't been accessed for more than
a configured time period.
@ -481,7 +492,7 @@ class DeviceHandler(DeviceWorkerHandler):
device_ids = [d for d in device_ids if d != except_device_id]
await self.delete_devices(user_id, device_ids)
async def delete_devices(self, user_id: str, device_ids: List[str]) -> None:
async def delete_devices(self, user_id: str, device_ids: Collection[str]) -> None:
"""Delete several devices
Args:

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@ -1533,6 +1533,70 @@ class DeviceBackgroundUpdateStore(SQLBaseStore):
return rows
async def check_too_many_devices_for_user(self, user_id: str) -> Collection[str]:
"""Check if the user has a lot of devices, and if so return the set of
devices we can prune.
This does *not* return hidden devices or devices with E2E keys.
"""
num_devices = await self.db_pool.simple_select_one_onecol(
table="devices",
keyvalues={"user_id": user_id, "hidden": False},
retcol="COALESCE(COUNT(*), 0)",
desc="count_devices",
)
# We let users have up to ten devices without pruning.
if num_devices <= 10:
return ()
# We prune everything older than N days.
max_last_seen = self._clock.time_msec() - 14 * 24 * 60 * 60 * 1000
if num_devices > 50:
# If the user has more than 50 devices, then we chose a last seen
# that ensures we keep at most 50 devices.
sql = """
SELECT last_seen FROM devices
WHERE
user_id = ?
AND NOT hidden
AND last_seen IS NOT NULL
AND key_json IS NULL
ORDER BY last_seen DESC
LIMIT 1
OFFSET 50
"""
rows = await self.db_pool.execute(
"check_too_many_devices_for_user_last_seen", None, sql, (user_id,)
)
if rows:
max_last_seen = max(rows[0][0], max_last_seen)
# Now fetch the devices to delete.
sql = """
SELECT DISTINCT device_id FROM devices
LEFT JOIN e2e_device_keys_json USING (user_id, device_id)
WHERE
user_id = ?
AND NOT hidden
AND last_seen < ?
AND key_json IS NULL
"""
def check_too_many_devices_for_user_txn(
txn: LoggingTransaction,
) -> Collection[str]:
txn.execute(sql, (user_id, max_last_seen))
return {device_id for device_id, in txn}
return await self.db_pool.runInteraction(
"check_too_many_devices_for_user",
check_too_many_devices_for_user_txn,
)
class DeviceStore(DeviceWorkerStore, DeviceBackgroundUpdateStore):
# Because we have write access, this will be a StreamIdGenerator
@ -1591,6 +1655,7 @@ class DeviceStore(DeviceWorkerStore, DeviceBackgroundUpdateStore):
values={},
insertion_values={
"display_name": initial_device_display_name,
"last_seen": self._clock.time_msec(),
"hidden": False,
},
desc="store_device",
@ -1636,7 +1701,7 @@ class DeviceStore(DeviceWorkerStore, DeviceBackgroundUpdateStore):
)
raise StoreError(500, "Problem storing device.")
async def delete_devices(self, user_id: str, device_ids: List[str]) -> None:
async def delete_devices(self, user_id: str, device_ids: Collection[str]) -> None:
"""Deletes several devices.
Args:

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@ -115,7 +115,7 @@ class DeviceTestCase(unittest.HomeserverTestCase):
"device_id": "xyz",
"display_name": "display 0",
"last_seen_ip": None,
"last_seen_ts": None,
"last_seen_ts": 1000000,
},
device_map["xyz"],
)

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@ -169,6 +169,8 @@ class ClientIpStoreTestCase(unittest.HomeserverTestCase):
)
)
last_seen = self.clock.time_msec()
if after_persisting:
# Trigger the storage loop
self.reactor.advance(10)
@ -189,7 +191,7 @@ class ClientIpStoreTestCase(unittest.HomeserverTestCase):
"device_id": device_id,
"ip": None,
"user_agent": None,
"last_seen": None,
"last_seen": last_seen,
},
],
)