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-rw-r--r--.travis.yml10
-rw-r--r--CONTRIBUTING.rst20
-rw-r--r--MANIFEST.in3
-rw-r--r--changelog.d/3324.removal1
-rw-r--r--changelog.d/3327.bugfix1
-rw-r--r--changelog.d/3332.misc0
-rw-r--r--changelog.d/3334.feature1
-rw-r--r--changelog.d/3340.doc1
-rw-r--r--changelog.d/3341.misc0
-rw-r--r--changelog.d/3344.feature1
-rw-r--r--changelog.d/3347.misc0
-rw-r--r--changelog.d/3348.misc0
-rw-r--r--changelog.d/3349.bugfix1
-rw-r--r--changelog.d/3355.bugfix1
-rw-r--r--changelog.d/3356.misc0
-rw-r--r--changelog.d/3363.bugfix1
-rw-r--r--changelog.d/3371.bugfix1
-rw-r--r--changelog.d/3372.feature1
-rw-r--r--pyproject.toml5
-rw-r--r--synapse/handlers/deactivate_account.py11
-rw-r--r--synapse/handlers/e2e_keys.py2
-rw-r--r--synapse/handlers/federation.py54
-rw-r--r--synapse/handlers/message.py12
-rw-r--r--synapse/handlers/presence.py4
-rw-r--r--synapse/handlers/sync.py2
-rw-r--r--synapse/http/endpoint.py18
-rw-r--r--synapse/push/emailpusher.py4
-rw-r--r--synapse/push/httppusher.py6
-rw-r--r--synapse/replication/slave/storage/events.py2
-rw-r--r--synapse/replication/tcp/client.py6
-rw-r--r--synapse/replication/tcp/resource.py4
-rw-r--r--synapse/rest/client/v1/admin.py4
-rw-r--r--synapse/rest/client/v2_alpha/account.py13
-rw-r--r--synapse/storage/__init__.py2
-rw-r--r--synapse/storage/schema/delta/50/erasure_store.sql21
-rw-r--r--synapse/storage/user_erasure_store.py103
-rw-r--r--synapse/util/__init__.py3
-rw-r--r--synapse/visibility.py77
-rw-r--r--tox.ini8
39 files changed, 350 insertions, 54 deletions
diff --git a/.travis.yml b/.travis.yml
index e6ba6f4752..a98d547978 100644
--- a/.travis.yml
+++ b/.travis.yml
@@ -4,7 +4,12 @@ language: python
 # tell travis to cache ~/.cache/pip
 cache: pip
 
+before_script:
+  - git remote set-branches --add origin develop
+  - git fetch origin develop
+
 matrix:
+  fast_finish: true
   include:
   - python: 2.7
     env: TOX_ENV=packaging
@@ -14,10 +19,13 @@ matrix:
 
   - python: 2.7
     env: TOX_ENV=py27
-    
+
   - python: 3.6
     env: TOX_ENV=py36
 
+  - python: 3.6
+    env: TOX_ENV=check-newsfragment
+
 install:
   - pip install tox
 
diff --git a/CONTRIBUTING.rst b/CONTRIBUTING.rst
index c6ee16efc7..954758afdc 100644
--- a/CONTRIBUTING.rst
+++ b/CONTRIBUTING.rst
@@ -48,6 +48,26 @@ Please ensure your changes match the cosmetic style of the existing project,
 and **never** mix cosmetic and functional changes in the same commit, as it
 makes it horribly hard to review otherwise.
 
+Changelog
+~~~~~~~~~
+
+All changes, even minor ones, need a corresponding changelog
+entry. These are managed by Towncrier
+(https://github.com/hawkowl/towncrier).
+
+To create a changelog entry, make a new file in the ``changelog.d``
+file named in the format of ``issuenumberOrPR.type``. The type can be
+one of ``feature``, ``bugfix``, ``removal`` (also used for
+deprecations), or ``misc`` (for internal-only changes). The content of
+the file is your changelog entry, which can contain RestructuredText
+formatting. A note of contributors is welcomed in changelogs for
+non-misc changes (the content of misc changes is not displayed).
+
+For example, a fix for a bug reported in #1234 would have its
+changelog entry in ``changelog.d/1234.bugfix``, and contain content
+like "The security levels of Florbs are now validated when
+recieved over federation. Contributed by Jane Matrix".
+
 Attribution
 ~~~~~~~~~~~
 
diff --git a/MANIFEST.in b/MANIFEST.in
index e2a6623a63..97f57f443f 100644
--- a/MANIFEST.in
+++ b/MANIFEST.in
@@ -29,5 +29,8 @@ exclude Dockerfile
 exclude .dockerignore
 recursive-exclude jenkins *.sh
 
+include pyproject.toml
+recursive-include changelog.d *
+
 prune .github
 prune demo/etc
diff --git a/changelog.d/3324.removal b/changelog.d/3324.removal
new file mode 100644
index 0000000000..11dc6a3d74
--- /dev/null
+++ b/changelog.d/3324.removal
@@ -0,0 +1 @@
+Remove was_forgotten_at
diff --git a/changelog.d/3327.bugfix b/changelog.d/3327.bugfix
new file mode 100644
index 0000000000..97e8c0a990
--- /dev/null
+++ b/changelog.d/3327.bugfix
@@ -0,0 +1 @@
+Strip access_token from outgoing requests 
diff --git a/changelog.d/3332.misc b/changelog.d/3332.misc
new file mode 100644
index 0000000000..e69de29bb2
--- /dev/null
+++ b/changelog.d/3332.misc
diff --git a/changelog.d/3334.feature b/changelog.d/3334.feature
new file mode 100644
index 0000000000..71c98f7262
--- /dev/null
+++ b/changelog.d/3334.feature
@@ -0,0 +1 @@
+Cache factor override system for specific caches
\ No newline at end of file
diff --git a/changelog.d/3340.doc b/changelog.d/3340.doc
new file mode 100644
index 0000000000..8395564ec7
--- /dev/null
+++ b/changelog.d/3340.doc
@@ -0,0 +1 @@
+``doc/postgres.rst``: fix display of the last command block. Thanks to @ArchangeGabriel!
diff --git a/changelog.d/3341.misc b/changelog.d/3341.misc
new file mode 100644
index 0000000000..e69de29bb2
--- /dev/null
+++ b/changelog.d/3341.misc
diff --git a/changelog.d/3344.feature b/changelog.d/3344.feature
new file mode 100644
index 0000000000..ab2e4fcef4
--- /dev/null
+++ b/changelog.d/3344.feature
@@ -0,0 +1 @@
+Add metrics to track appservice transactions
diff --git a/changelog.d/3347.misc b/changelog.d/3347.misc
new file mode 100644
index 0000000000..e69de29bb2
--- /dev/null
+++ b/changelog.d/3347.misc
diff --git a/changelog.d/3348.misc b/changelog.d/3348.misc
new file mode 100644
index 0000000000..e69de29bb2
--- /dev/null
+++ b/changelog.d/3348.misc
diff --git a/changelog.d/3349.bugfix b/changelog.d/3349.bugfix
new file mode 100644
index 0000000000..aa45bab3ba
--- /dev/null
+++ b/changelog.d/3349.bugfix
@@ -0,0 +1 @@
+Redact AS tokens in logs
diff --git a/changelog.d/3355.bugfix b/changelog.d/3355.bugfix
new file mode 100644
index 0000000000..80105a0e95
--- /dev/null
+++ b/changelog.d/3355.bugfix
@@ -0,0 +1 @@
+Fix federation backfill from SQLite servers
diff --git a/changelog.d/3356.misc b/changelog.d/3356.misc
new file mode 100644
index 0000000000..e69de29bb2
--- /dev/null
+++ b/changelog.d/3356.misc
diff --git a/changelog.d/3363.bugfix b/changelog.d/3363.bugfix
new file mode 100644
index 0000000000..d8895195c2
--- /dev/null
+++ b/changelog.d/3363.bugfix
@@ -0,0 +1 @@
+Fix event-purge-by-ts admin API
diff --git a/changelog.d/3371.bugfix b/changelog.d/3371.bugfix
new file mode 100644
index 0000000000..553f2b126e
--- /dev/null
+++ b/changelog.d/3371.bugfix
@@ -0,0 +1 @@
+Fix event filtering in get_missing_events handler
diff --git a/changelog.d/3372.feature b/changelog.d/3372.feature
new file mode 100644
index 0000000000..7f58f3ccac
--- /dev/null
+++ b/changelog.d/3372.feature
@@ -0,0 +1 @@
+Try to log more helpful info when a sig verification fails
diff --git a/pyproject.toml b/pyproject.toml
new file mode 100644
index 0000000000..d1603b5d8b
--- /dev/null
+++ b/pyproject.toml
@@ -0,0 +1,5 @@
+[tool.towncrier]
+    package = "synapse"
+    filename = "CHANGES.rst"
+    directory = "changelog.d"
+    issue_format = "`#{issue} <https://github.com/matrix-org/synapse/issues/{issue}>`_"
diff --git a/synapse/handlers/deactivate_account.py b/synapse/handlers/deactivate_account.py
index 8ec5ba2012..a18d95397c 100644
--- a/synapse/handlers/deactivate_account.py
+++ b/synapse/handlers/deactivate_account.py
@@ -12,7 +12,7 @@
 # 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.
-from twisted.internet import defer, reactor
+from twisted.internet import defer
 
 from ._base import BaseHandler
 from synapse.types import UserID, create_requester
@@ -39,10 +39,10 @@ class DeactivateAccountHandler(BaseHandler):
 
         # Start the user parter loop so it can resume parting users from rooms where
         # it left off (if it has work left to do).
-        reactor.callWhenRunning(self._start_user_parting)
+        hs.get_reactor().callWhenRunning(self._start_user_parting)
 
     @defer.inlineCallbacks
-    def deactivate_account(self, user_id):
+    def deactivate_account(self, user_id, erase_data):
         """Deactivate a user's account
 
         Args:
@@ -92,6 +92,11 @@ class DeactivateAccountHandler(BaseHandler):
         # delete from user directory
         yield self.user_directory_handler.handle_user_deactivated(user_id)
 
+        # Mark the user as erased, if they asked for that
+        if erase_data:
+            logger.info("Marking %s as erased", user_id)
+            yield self.store.mark_user_erased(user_id)
+
         # Now start the process that goes through that list and
         # parts users from rooms (if it isn't already running)
         self._start_user_parting()
diff --git a/synapse/handlers/e2e_keys.py b/synapse/handlers/e2e_keys.py
index 8a2d177539..4d7bf5defd 100644
--- a/synapse/handlers/e2e_keys.py
+++ b/synapse/handlers/e2e_keys.py
@@ -80,7 +80,7 @@ class E2eKeysHandler(object):
             else:
                 remote_queries[user_id] = device_ids
 
-        # Firt get local devices.
+        # First get local devices.
         failures = {}
         results = {}
         if local_query:
diff --git a/synapse/handlers/federation.py b/synapse/handlers/federation.py
index 2571758284..b6f8d4cf82 100644
--- a/synapse/handlers/federation.py
+++ b/synapse/handlers/federation.py
@@ -460,6 +460,47 @@ class FederationHandler(BaseHandler):
     @measure_func("_filter_events_for_server")
     @defer.inlineCallbacks
     def _filter_events_for_server(self, server_name, room_id, events):
+        """Filter the given events for the given server, redacting those the
+        server can't see.
+
+        Assumes the server is currently in the room.
+
+        Returns
+            list[FrozenEvent]
+        """
+        # First lets check to see if all the events have a history visibility
+        # of "shared" or "world_readable". If thats the case then we don't
+        # need to check membership (as we know the server is in the room).
+        event_to_state_ids = yield self.store.get_state_ids_for_events(
+            frozenset(e.event_id for e in events),
+            types=(
+                (EventTypes.RoomHistoryVisibility, ""),
+            )
+        )
+
+        visibility_ids = set()
+        for sids in event_to_state_ids.itervalues():
+            hist = sids.get((EventTypes.RoomHistoryVisibility, ""))
+            if hist:
+                visibility_ids.add(hist)
+
+        # If we failed to find any history visibility events then the default
+        # is "shared" visiblity.
+        if not visibility_ids:
+            defer.returnValue(events)
+
+        event_map = yield self.store.get_events(visibility_ids)
+        all_open = all(
+            e.content.get("history_visibility") in (None, "shared", "world_readable")
+            for e in event_map.itervalues()
+        )
+
+        if all_open:
+            defer.returnValue(events)
+
+        # Ok, so we're dealing with events that have non-trivial visibility
+        # rules, so we need to also get the memberships of the room.
+
         event_to_state_ids = yield self.store.get_state_ids_for_events(
             frozenset(e.event_id for e in events),
             types=(
@@ -495,7 +536,20 @@ class FederationHandler(BaseHandler):
             for e_id, key_to_eid in event_to_state_ids.iteritems()
         }
 
+        erased_senders = yield self.store.are_users_erased(
+            e.sender for e in events,
+        )
+
         def redact_disallowed(event, state):
+            # if the sender has been gdpr17ed, always return a redacted
+            # copy of the event.
+            if erased_senders[event.sender]:
+                logger.info(
+                    "Sender of %s has been erased, redacting",
+                    event.event_id,
+                )
+                return prune_event(event)
+
             if not state:
                 return event
 
diff --git a/synapse/handlers/message.py b/synapse/handlers/message.py
index 7b9946ab91..8467284758 100644
--- a/synapse/handlers/message.py
+++ b/synapse/handlers/message.py
@@ -20,7 +20,7 @@ import sys
 from canonicaljson import encode_canonical_json
 import six
 from six import string_types, itervalues, iteritems
-from twisted.internet import defer, reactor
+from twisted.internet import defer
 from twisted.internet.defer import succeed
 from twisted.python.failure import Failure
 
@@ -157,7 +157,7 @@ class MessageHandler(BaseHandler):
             # remove the purge from the list 24 hours after it completes
             def clear_purge():
                 del self._purges_by_id[purge_id]
-            reactor.callLater(24 * 3600, clear_purge)
+            self.hs.get_reactor().callLater(24 * 3600, clear_purge)
 
     def get_purge_status(self, purge_id):
         """Get the current status of an active purge
@@ -491,7 +491,7 @@ class EventCreationHandler(object):
                         target, e
                     )
 
-        is_exempt = yield self._is_exempt_from_privacy_policy(builder)
+        is_exempt = yield self._is_exempt_from_privacy_policy(builder, requester)
         if not is_exempt:
             yield self.assert_accepted_privacy_policy(requester)
 
@@ -509,12 +509,13 @@ class EventCreationHandler(object):
 
         defer.returnValue((event, context))
 
-    def _is_exempt_from_privacy_policy(self, builder):
+    def _is_exempt_from_privacy_policy(self, builder, requester):
         """"Determine if an event to be sent is exempt from having to consent
         to the privacy policy
 
         Args:
             builder (synapse.events.builder.EventBuilder): event being created
+            requester (Requster): user requesting this event
 
         Returns:
             Deferred[bool]: true if the event can be sent without the user
@@ -525,6 +526,9 @@ class EventCreationHandler(object):
             membership = builder.content.get("membership", None)
             if membership == Membership.JOIN:
                 return self._is_server_notices_room(builder.room_id)
+            elif membership == Membership.LEAVE:
+                # the user is always allowed to leave (but not kick people)
+                return builder.state_key == requester.user.to_string()
         return succeed(False)
 
     @defer.inlineCallbacks
diff --git a/synapse/handlers/presence.py b/synapse/handlers/presence.py
index 7fe568132f..7db59fba00 100644
--- a/synapse/handlers/presence.py
+++ b/synapse/handlers/presence.py
@@ -22,7 +22,7 @@ The methods that define policy are:
     - should_notify
 """
 
-from twisted.internet import defer, reactor
+from twisted.internet import defer
 from contextlib import contextmanager
 
 from six import itervalues, iteritems
@@ -179,7 +179,7 @@ class PresenceHandler(object):
         # have not yet been persisted
         self.unpersisted_users_changes = set()
 
-        reactor.addSystemEventTrigger("before", "shutdown", self._on_shutdown)
+        hs.get_reactor().addSystemEventTrigger("before", "shutdown", self._on_shutdown)
 
         self.serial_to_user = {}
         self._next_serial = 1
diff --git a/synapse/handlers/sync.py b/synapse/handlers/sync.py
index 51ec727df0..7f486e48e5 100644
--- a/synapse/handlers/sync.py
+++ b/synapse/handlers/sync.py
@@ -145,7 +145,7 @@ class SyncResult(collections.namedtuple("SyncResult", [
     "invited",  # InvitedSyncResult for each invited room.
     "archived",  # ArchivedSyncResult for each archived room.
     "to_device",  # List of direct messages for the device.
-    "device_lists",  # List of user_ids whose devices have chanegd
+    "device_lists",  # List of user_ids whose devices have changed
     "device_one_time_keys_count",  # Dict of algorithm to count for one time keys
                                    # for this device
     "groups",
diff --git a/synapse/http/endpoint.py b/synapse/http/endpoint.py
index 87a482650d..80da870584 100644
--- a/synapse/http/endpoint.py
+++ b/synapse/http/endpoint.py
@@ -13,7 +13,7 @@
 # See the License for the specific language governing permissions and
 # limitations under the License.
 from twisted.internet.endpoints import HostnameEndpoint, wrapClientTLS
-from twisted.internet import defer, reactor
+from twisted.internet import defer
 from twisted.internet.error import ConnectError
 from twisted.names import client, dns
 from twisted.names.error import DNSNameError, DomainError
@@ -74,21 +74,22 @@ def matrix_federation_endpoint(reactor, destination, ssl_context_factory=None,
             reactor, "matrix", domain, protocol="tcp",
             default_port=default_port, endpoint=transport_endpoint,
             endpoint_kw_args=endpoint_kw_args
-        ))
+        ), reactor)
     else:
         return _WrappingEndpointFac(transport_endpoint(
             reactor, domain, port, **endpoint_kw_args
-        ))
+        ), reactor)
 
 
 class _WrappingEndpointFac(object):
-    def __init__(self, endpoint_fac):
+    def __init__(self, endpoint_fac, reactor):
         self.endpoint_fac = endpoint_fac
+        self.reactor = reactor
 
     @defer.inlineCallbacks
     def connect(self, protocolFactory):
         conn = yield self.endpoint_fac.connect(protocolFactory)
-        conn = _WrappedConnection(conn)
+        conn = _WrappedConnection(conn, self.reactor)
         defer.returnValue(conn)
 
 
@@ -98,9 +99,10 @@ class _WrappedConnection(object):
     """
     __slots__ = ["conn", "last_request"]
 
-    def __init__(self, conn):
+    def __init__(self, conn, reactor):
         object.__setattr__(self, "conn", conn)
         object.__setattr__(self, "last_request", time.time())
+        self._reactor = reactor
 
     def __getattr__(self, name):
         return getattr(self.conn, name)
@@ -131,14 +133,14 @@ class _WrappedConnection(object):
         # Time this connection out if we haven't send a request in the last
         # N minutes
         # TODO: Cancel the previous callLater?
-        reactor.callLater(3 * 60, self._time_things_out_maybe)
+        self._reactor.callLater(3 * 60, self._time_things_out_maybe)
 
         d = self.conn.request(request)
 
         def update_request_time(res):
             self.last_request = time.time()
             # TODO: Cancel the previous callLater?
-            reactor.callLater(3 * 60, self._time_things_out_maybe)
+            self._reactor.callLater(3 * 60, self._time_things_out_maybe)
             return res
 
         d.addCallback(update_request_time)
diff --git a/synapse/push/emailpusher.py b/synapse/push/emailpusher.py
index ba7286cb72..52d4f087ee 100644
--- a/synapse/push/emailpusher.py
+++ b/synapse/push/emailpusher.py
@@ -13,7 +13,7 @@
 # See the License for the specific language governing permissions and
 # limitations under the License.
 
-from twisted.internet import defer, reactor
+from twisted.internet import defer
 from twisted.internet.error import AlreadyCalled, AlreadyCancelled
 
 import logging
@@ -199,7 +199,7 @@ class EmailPusher(object):
                     self.timed_call = None
 
         if soonest_due_at is not None:
-            self.timed_call = reactor.callLater(
+            self.timed_call = self.hs.get_reactor().callLater(
                 self.seconds_until(soonest_due_at), self.on_timer
             )
 
diff --git a/synapse/push/httppusher.py b/synapse/push/httppusher.py
index bf7ff74a1a..7a481b5a1e 100644
--- a/synapse/push/httppusher.py
+++ b/synapse/push/httppusher.py
@@ -15,7 +15,7 @@
 # limitations under the License.
 import logging
 
-from twisted.internet import defer, reactor
+from twisted.internet import defer
 from twisted.internet.error import AlreadyCalled, AlreadyCancelled
 
 from . import push_rule_evaluator
@@ -220,7 +220,9 @@ class HttpPusher(object):
                     )
                 else:
                     logger.info("Push failed: delaying for %ds", self.backoff_delay)
-                    self.timed_call = reactor.callLater(self.backoff_delay, self.on_timer)
+                    self.timed_call = self.hs.get_reactor().callLater(
+                        self.backoff_delay, self.on_timer
+                    )
                     self.backoff_delay = min(self.backoff_delay * 2, self.MAX_BACKOFF_SEC)
                     break
 
diff --git a/synapse/replication/slave/storage/events.py b/synapse/replication/slave/storage/events.py
index b1f64ef0d8..97d3196633 100644
--- a/synapse/replication/slave/storage/events.py
+++ b/synapse/replication/slave/storage/events.py
@@ -23,6 +23,7 @@ from synapse.storage.roommember import RoomMemberWorkerStore
 from synapse.storage.state import StateGroupWorkerStore
 from synapse.storage.stream import StreamWorkerStore
 from synapse.storage.signatures import SignatureWorkerStore
+from synapse.storage.user_erasure_store import UserErasureWorkerStore
 from ._base import BaseSlavedStore
 from ._slaved_id_tracker import SlavedIdTracker
 
@@ -45,6 +46,7 @@ class SlavedEventStore(EventFederationWorkerStore,
                        EventsWorkerStore,
                        StateGroupWorkerStore,
                        SignatureWorkerStore,
+                       UserErasureWorkerStore,
                        BaseSlavedStore):
 
     def __init__(self, db_conn, hs):
diff --git a/synapse/replication/tcp/client.py b/synapse/replication/tcp/client.py
index 6d2513c4e2..bb852b00af 100644
--- a/synapse/replication/tcp/client.py
+++ b/synapse/replication/tcp/client.py
@@ -15,7 +15,7 @@
 """A replication client for use by synapse workers.
 """
 
-from twisted.internet import reactor, defer
+from twisted.internet import defer
 from twisted.internet.protocol import ReconnectingClientFactory
 
 from .commands import (
@@ -44,7 +44,7 @@ class ReplicationClientFactory(ReconnectingClientFactory):
         self.server_name = hs.config.server_name
         self._clock = hs.get_clock()  # As self.clock is defined in super class
 
-        reactor.addSystemEventTrigger("before", "shutdown", self.stopTrying)
+        hs.get_reactor().addSystemEventTrigger("before", "shutdown", self.stopTrying)
 
     def startedConnecting(self, connector):
         logger.info("Connecting to replication: %r", connector.getDestination())
@@ -95,7 +95,7 @@ class ReplicationClientHandler(object):
         factory = ReplicationClientFactory(hs, client_name, self)
         host = hs.config.worker_replication_host
         port = hs.config.worker_replication_port
-        reactor.connectTCP(host, port, factory)
+        hs.get_reactor().connectTCP(host, port, factory)
 
     def on_rdata(self, stream_name, token, rows):
         """Called when we get new replication data. By default this just pokes
diff --git a/synapse/replication/tcp/resource.py b/synapse/replication/tcp/resource.py
index 63bd6d2652..95ad8c1b4c 100644
--- a/synapse/replication/tcp/resource.py
+++ b/synapse/replication/tcp/resource.py
@@ -15,7 +15,7 @@
 """The server side of the replication stream.
 """
 
-from twisted.internet import defer, reactor
+from twisted.internet import defer
 from twisted.internet.protocol import Factory
 
 from .streams import STREAMS_MAP, FederationStream
@@ -109,7 +109,7 @@ class ReplicationStreamer(object):
         self.is_looping = False
         self.pending_updates = False
 
-        reactor.addSystemEventTrigger("before", "shutdown", self.on_shutdown)
+        hs.get_reactor().addSystemEventTrigger("before", "shutdown", self.on_shutdown)
 
     def on_shutdown(self):
         # close all connections on shutdown
diff --git a/synapse/rest/client/v1/admin.py b/synapse/rest/client/v1/admin.py
index b8665a45eb..ddaedb2a8c 100644
--- a/synapse/rest/client/v1/admin.py
+++ b/synapse/rest/client/v1/admin.py
@@ -254,7 +254,9 @@ class DeactivateAccountRestServlet(ClientV1RestServlet):
         if not is_admin:
             raise AuthError(403, "You are not a server admin")
 
-        yield self._deactivate_account_handler.deactivate_account(target_user_id)
+        yield self._deactivate_account_handler.deactivate_account(
+            target_user_id, False,
+        )
         defer.returnValue((200, {}))
 
 
diff --git a/synapse/rest/client/v2_alpha/account.py b/synapse/rest/client/v2_alpha/account.py
index e1281cfbb6..80dbc3c92e 100644
--- a/synapse/rest/client/v2_alpha/account.py
+++ b/synapse/rest/client/v2_alpha/account.py
@@ -1,6 +1,7 @@
 # -*- coding: utf-8 -*-
 # Copyright 2015, 2016 OpenMarket Ltd
 # Copyright 2017 Vector Creations Ltd
+# Copyright 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.
@@ -15,6 +16,7 @@
 # limitations under the License.
 import logging
 
+from six.moves import http_client
 from twisted.internet import defer
 
 from synapse.api.auth import has_access_token
@@ -186,13 +188,20 @@ class DeactivateAccountRestServlet(RestServlet):
     @defer.inlineCallbacks
     def on_POST(self, request):
         body = parse_json_object_from_request(request)
+        erase = body.get("erase", False)
+        if not isinstance(erase, bool):
+            raise SynapseError(
+                http_client.BAD_REQUEST,
+                "Param 'erase' must be a boolean, if given",
+                Codes.BAD_JSON,
+            )
 
         requester = yield self.auth.get_user_by_req(request)
 
         # allow ASes to dectivate their own users
         if requester.app_service:
             yield self._deactivate_account_handler.deactivate_account(
-                requester.user.to_string()
+                requester.user.to_string(), erase,
             )
             defer.returnValue((200, {}))
 
@@ -200,7 +209,7 @@ class DeactivateAccountRestServlet(RestServlet):
             requester, body, self.hs.get_ip_from_request(request),
         )
         yield self._deactivate_account_handler.deactivate_account(
-            requester.user.to_string(),
+            requester.user.to_string(), erase,
         )
         defer.returnValue((200, {}))
 
diff --git a/synapse/storage/__init__.py b/synapse/storage/__init__.py
index 979fa22438..e843b702b9 100644
--- a/synapse/storage/__init__.py
+++ b/synapse/storage/__init__.py
@@ -20,6 +20,7 @@ import time
 import logging
 
 from synapse.storage.devices import DeviceStore
+from synapse.storage.user_erasure_store import UserErasureStore
 from .appservice import (
     ApplicationServiceStore, ApplicationServiceTransactionStore
 )
@@ -88,6 +89,7 @@ class DataStore(RoomMemberStore, RoomStore,
                 DeviceInboxStore,
                 UserDirectoryStore,
                 GroupServerStore,
+                UserErasureStore,
                 ):
 
     def __init__(self, db_conn, hs):
diff --git a/synapse/storage/schema/delta/50/erasure_store.sql b/synapse/storage/schema/delta/50/erasure_store.sql
new file mode 100644
index 0000000000..5d8641a9ab
--- /dev/null
+++ b/synapse/storage/schema/delta/50/erasure_store.sql
@@ -0,0 +1,21 @@
+/* Copyright 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.
+ * 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.
+ */
+
+-- a table of users who have requested that their details be erased
+CREATE TABLE erased_users (
+    user_id TEXT NOT NULL
+);
+
+CREATE UNIQUE INDEX erased_users_user ON erased_users(user_id);
diff --git a/synapse/storage/user_erasure_store.py b/synapse/storage/user_erasure_store.py
new file mode 100644
index 0000000000..47bfc01e84
--- /dev/null
+++ b/synapse/storage/user_erasure_store.py
@@ -0,0 +1,103 @@
+# -*- coding: utf-8 -*-
+# Copyright 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.
+# 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 operator
+
+from twisted.internet import defer
+
+from synapse.storage._base import SQLBaseStore
+from synapse.util.caches.descriptors import cachedList, cached
+
+
+class UserErasureWorkerStore(SQLBaseStore):
+    @cached()
+    def is_user_erased(self, user_id):
+        """
+        Check if the given user id has requested erasure
+
+        Args:
+            user_id (str): full user id to check
+
+        Returns:
+            Deferred[bool]: True if the user has requested erasure
+        """
+        return self._simple_select_onecol(
+            table="erased_users",
+            keyvalues={"user_id": user_id},
+            retcol="1",
+            desc="is_user_erased",
+        ).addCallback(operator.truth)
+
+    @cachedList(
+        cached_method_name="is_user_erased",
+        list_name="user_ids",
+        inlineCallbacks=True,
+    )
+    def are_users_erased(self, user_ids):
+        """
+        Checks which users in a list have requested erasure
+
+        Args:
+            user_ids (iterable[str]): full user id to check
+
+        Returns:
+            Deferred[dict[str, bool]]:
+                for each user, whether the user has requested erasure.
+        """
+        # this serves the dual purpose of (a) making sure we can do len and
+        # iterate it multiple times, and (b) avoiding duplicates.
+        user_ids = tuple(set(user_ids))
+
+        def _get_erased_users(txn):
+            txn.execute(
+                "SELECT user_id FROM erased_users WHERE user_id IN (%s)" % (
+                    ",".join("?" * len(user_ids))
+                ),
+                user_ids,
+            )
+            return set(r[0] for r in txn)
+
+        erased_users = yield self.runInteraction(
+            "are_users_erased", _get_erased_users,
+        )
+        res = dict((u, u in erased_users) for u in user_ids)
+        defer.returnValue(res)
+
+
+class UserErasureStore(UserErasureWorkerStore):
+    def mark_user_erased(self, user_id):
+        """Indicate that user_id wishes their message history to be erased.
+
+        Args:
+            user_id (str): full user_id to be erased
+        """
+        def f(txn):
+            # first check if they are already in the list
+            txn.execute(
+                "SELECT 1 FROM erased_users WHERE user_id = ?",
+                (user_id, )
+            )
+            if txn.fetchone():
+                return
+
+            # they are not already there: do the insert.
+            txn.execute(
+                "INSERT INTO erased_users (user_id) VALUES (?)",
+                (user_id, )
+            )
+
+            self._invalidate_cache_and_stream(
+                txn, self.is_user_erased, (user_id,)
+            )
+        return self.runInteraction("mark_user_erased", f)
diff --git a/synapse/util/__init__.py b/synapse/util/__init__.py
index 2a3df7c71d..e9886ef299 100644
--- a/synapse/util/__init__.py
+++ b/synapse/util/__init__.py
@@ -34,6 +34,9 @@ def unwrapFirstError(failure):
 class Clock(object):
     """
     A Clock wraps a Twisted reactor and provides utilities on top of it.
+
+    Args:
+        reactor: The Twisted reactor to use.
     """
     _reactor = attr.ib()
 
diff --git a/synapse/visibility.py b/synapse/visibility.py
index aef4953c1d..65d79cf0d0 100644
--- a/synapse/visibility.py
+++ b/synapse/visibility.py
@@ -12,15 +12,17 @@
 # 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 itertools
 import logging
+import operator
 
 from twisted.internet import defer
 
-from synapse.api.constants import Membership, EventTypes
-
-from synapse.util.logcontext import make_deferred_yieldable, preserve_fn
-
+from synapse.api.constants import EventTypes, Membership
+from synapse.events.utils import prune_event
+from synapse.util.logcontext import (
+    make_deferred_yieldable, preserve_fn,
+)
 
 logger = logging.getLogger(__name__)
 
@@ -95,16 +97,27 @@ def filter_events_for_client(store, user_id, events, is_peeking=False,
         if ignore_dict_content else []
     )
 
+    erased_senders = yield store.are_users_erased((e.sender for e in events))
+
     def allowed(event):
         """
         Args:
             event (synapse.events.EventBase): event to check
+
+        Returns:
+            None|EventBase:
+               None if the user cannot see this event at all
+
+               a redacted copy of the event if they can only see a redacted
+               version
+
+               the original event if they can see it as normal.
         """
         if not event.is_state() and event.sender in ignore_list:
-            return False
+            return None
 
         if event.event_id in always_include_ids:
-            return True
+            return event
 
         state = event_id_to_state[event.event_id]
 
@@ -118,10 +131,6 @@ def filter_events_for_client(store, user_id, events, is_peeking=False,
         if visibility not in VISIBILITY_PRIORITY:
             visibility = "shared"
 
-        # if it was world_readable, it's easy: everyone can read it
-        if visibility == "world_readable":
-            return True
-
         # Always allow history visibility events on boundaries. This is done
         # by setting the effective visibility to the least restrictive
         # of the old vs new.
@@ -155,7 +164,7 @@ def filter_events_for_client(store, user_id, events, is_peeking=False,
             if membership == "leave" and (
                 prev_membership == "join" or prev_membership == "invite"
             ):
-                return True
+                return event
 
             new_priority = MEMBERSHIP_PRIORITY.index(membership)
             old_priority = MEMBERSHIP_PRIORITY.index(prev_membership)
@@ -166,31 +175,55 @@ def filter_events_for_client(store, user_id, events, is_peeking=False,
         if membership is None:
             membership_event = state.get((EventTypes.Member, user_id), None)
             if membership_event:
+                # XXX why do we do this?
+                # https://github.com/matrix-org/synapse/issues/3350
                 if membership_event.event_id not in event_id_forgotten:
                     membership = membership_event.membership
 
         # if the user was a member of the room at the time of the event,
         # they can see it.
         if membership == Membership.JOIN:
-            return True
+            return event
+
+        # otherwise, it depends on the room visibility.
 
         if visibility == "joined":
             # we weren't a member at the time of the event, so we can't
             # see this event.
-            return False
+            return None
 
         elif visibility == "invited":
             # user can also see the event if they were *invited* at the time
             # of the event.
-            return membership == Membership.INVITE
-
-        else:
-            # visibility is shared: user can also see the event if they have
-            # become a member since the event
+            return (
+                event if membership == Membership.INVITE else None
+            )
+
+        elif visibility == "shared" and is_peeking:
+            # if the visibility is shared, users cannot see the event unless
+            # they have *subequently* joined the room (or were members at the
+            # time, of course)
             #
             # XXX: if the user has subsequently joined and then left again,
             # ideally we would share history up to the point they left. But
-            # we don't know when they left.
-            return not is_peeking
+            # we don't know when they left. We just treat it as though they
+            # never joined, and restrict access.
+            return None
+
+        # the visibility is either shared or world_readable, and the user was
+        # not a member at the time. We allow it, provided the original sender
+        # has not requested their data to be erased, in which case, we return
+        # a redacted version.
+        if erased_senders[event.sender]:
+            return prune_event(event)
+
+        return event
+
+    # check each event: gives an iterable[None|EventBase]
+    filtered_events = itertools.imap(allowed, events)
+
+    # remove the None entries
+    filtered_events = filter(operator.truth, filtered_events)
 
-    defer.returnValue(list(filter(allowed, events)))
+    # we turn it into a list before returning it.
+    defer.returnValue(list(filtered_events))
diff --git a/tox.ini b/tox.ini
index 5d79098d2f..61a20a10cb 100644
--- a/tox.ini
+++ b/tox.ini
@@ -102,3 +102,11 @@ basepython = python2.7
 deps =
     flake8
 commands = /bin/sh -c "flake8 synapse tests {env:PEP8SUFFIX:}"
+
+
+[testenv:check-newsfragment]
+skip_install = True
+deps = towncrier>=18.6.0rc1
+commands =
+   python -m towncrier.check --compare-with=origin/develop
+basepython = python3.6
\ No newline at end of file