Merge branch 'develop' of github.com:matrix-org/synapse into anoa/user_param_ui_auth github/anoa/user_param_ui_auth anoa/user_param_ui_auth

* 'develop' of github.com:matrix-org/synapse: (369 commits)
  Add functions to `MultiWriterIdGen` used by events stream (#8164)
  Do not allow send_nonmember_event to be called with shadow-banned users. (#8158)
  Changelog fixes
  1.19.1rc1
  Make StreamIdGen `get_next` and `get_next_mult` async  (#8161)
  Wording fixes to 'name' user admin api filter (#8163)
  Fix missing double-backtick in RST document
  Search in columns 'name' and 'displayname' in the admin users endpoint (#7377)
  Add type hints for state. (#8140)
  Stop shadow-banned users from sending non-member events. (#8142)
  Allow capping a room's retention policy (#8104)
  Add healthcheck for default localhost 8008 port on /health endpoint. (#8147)
  Fix flaky shadow-ban tests. (#8152)
  Fix join ratelimiter breaking profile updates and idempotency (#8153)
  Do not apply ratelimiting on joins to appservices (#8139)
  Don't fail /submit_token requests on incorrect session ID if request_token_inhibit_3pid_errors is turned on (#7991)
  Do not apply ratelimiting on joins to appservices (#8139)
  Micro-optimisations to get_auth_chain_ids (#8132)
  Allow denying or shadow banning registrations via the spam checker (#8034)
  Stop shadow-banned users from sending invites. (#8095)
  ...

7 files changed, 273 insertions, 150 deletions

diff --git a/synapse/api/auth.py b/synapse/api/auth.py
index 06ade25674..7aab764360 100644
--- a/synapse/api/auth.py
+++ b/synapse/api/auth.py
@@ -12,19 +12,14 @@
 # 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 logging
-from typing import Optional
-
-from six import itervalues
+from typing import List, Optional, Tuple
 
 import pymacaroons
 from netaddr import IPAddress
 
-from twisted.internet import defer
 from twisted.web.server import Request
 
-import synapse.logging.opentracing as opentracing
 import synapse.types
 from synapse import event_auth
 from synapse.api.auth_blocking import AuthBlocking
@@ -37,6 +32,7 @@ from synapse.api.errors import (
 )
 from synapse.api.room_versions import KNOWN_ROOM_VERSIONS
 from synapse.events import EventBase
+from synapse.logging import opentracing as opentracing
 from synapse.types import StateMap, UserID
 from synapse.util.caches import register_cache
 from synapse.util.caches.lrucache import LruCache
@@ -83,28 +79,28 @@ class Auth(object):
         self._track_appservice_user_ips = hs.config.track_appservice_user_ips
         self._macaroon_secret_key = hs.config.macaroon_secret_key
 
-    @defer.inlineCallbacks
-    def check_from_context(self, room_version: str, event, context, do_sig_check=True):
-        prev_state_ids = yield context.get_prev_state_ids()
-        auth_events_ids = yield self.compute_auth_events(
+    async def check_from_context(
+        self, room_version: str, event, context, do_sig_check=True
+    ):
+        prev_state_ids = await context.get_prev_state_ids()
+        auth_events_ids = self.compute_auth_events(
             event, prev_state_ids, for_verification=True
         )
-        auth_events = yield self.store.get_events(auth_events_ids)
-        auth_events = {(e.type, e.state_key): e for e in itervalues(auth_events)}
+        auth_events = await self.store.get_events(auth_events_ids)
+        auth_events = {(e.type, e.state_key): e for e in auth_events.values()}
 
         room_version_obj = KNOWN_ROOM_VERSIONS[room_version]
         event_auth.check(
             room_version_obj, event, auth_events=auth_events, do_sig_check=do_sig_check
         )
 
-    @defer.inlineCallbacks
-    def check_user_in_room(
+    async def check_user_in_room(
         self,
         room_id: str,
         user_id: str,
         current_state: Optional[StateMap[EventBase]] = None,
         allow_departed_users: bool = False,
-    ):
+    ) -> EventBase:
         """Check if the user is in the room, or was at some point.
         Args:
             room_id: The room to check.
@@ -122,35 +118,35 @@ class Auth(object):
         Raises:
             AuthError if the user is/was not in the room.
         Returns:
-            Deferred[Optional[EventBase]]:
-                Membership event for the user if the user was in the
-                room. This will be the join event if they are currently joined to
-                the room. This will be the leave event if they have left the room.
+            Membership event for the user if the user was in the
+            room. This will be the join event if they are currently joined to
+            the room. This will be the leave event if they have left the room.
         """
         if current_state:
             member = current_state.get((EventTypes.Member, user_id), None)
         else:
-            member = yield self.state.get_current_state(
+            member = await self.state.get_current_state(
                 room_id=room_id, event_type=EventTypes.Member, state_key=user_id
             )
-        membership = member.membership if member else None
 
-        if membership == Membership.JOIN:
-            return member
+        if member:
+            membership = member.membership
 
-        # XXX this looks totally bogus. Why do we not allow users who have been banned,
-        # or those who were members previously and have been re-invited?
-        if allow_departed_users and membership == Membership.LEAVE:
-            forgot = yield self.store.did_forget(user_id, room_id)
-            if not forgot:
+            if membership == Membership.JOIN:
                 return member
 
+            # XXX this looks totally bogus. Why do we not allow users who have been banned,
+            # or those who were members previously and have been re-invited?
+            if allow_departed_users and membership == Membership.LEAVE:
+                forgot = await self.store.did_forget(user_id, room_id)
+                if not forgot:
+                    return member
+
         raise AuthError(403, "User %s not in room %s" % (user_id, room_id))
 
-    @defer.inlineCallbacks
-    def check_host_in_room(self, room_id, host):
+    async def check_host_in_room(self, room_id, host):
         with Measure(self.clock, "check_host_in_room"):
-            latest_event_ids = yield self.store.is_host_joined(room_id, host)
+            latest_event_ids = await self.store.is_host_joined(room_id, host)
             return latest_event_ids
 
     def can_federate(self, event, auth_events):
@@ -161,14 +157,13 @@ class Auth(object):
     def get_public_keys(self, invite_event):
         return event_auth.get_public_keys(invite_event)
 
-    @defer.inlineCallbacks
-    def get_user_by_req(
+    async def get_user_by_req(
         self,
         request: Request,
         allow_guest: bool = False,
         rights: str = "access",
         allow_expired: bool = False,
-    ):
+    ) -> synapse.types.Requester:
         """ Get a registered user's ID.
 
         Args:
@@ -181,7 +176,7 @@ class Auth(object):
                 /login will deliver access tokens regardless of expiration.
 
         Returns:
-            defer.Deferred: resolves to a `synapse.types.Requester` object
+            Resolves to the requester
         Raises:
             InvalidClientCredentialsError if no user by that token exists or the token
                 is invalid.
@@ -195,14 +190,14 @@ class Auth(object):
 
             access_token = self.get_access_token_from_request(request)
 
-            user_id, app_service = yield self._get_appservice_user_id(request)
+            user_id, app_service = await self._get_appservice_user_id(request)
             if user_id:
                 request.authenticated_entity = user_id
                 opentracing.set_tag("authenticated_entity", user_id)
                 opentracing.set_tag("appservice_id", app_service.id)
 
                 if ip_addr and self._track_appservice_user_ips:
-                    yield self.store.insert_client_ip(
+                    await self.store.insert_client_ip(
                         user_id=user_id,
                         access_token=access_token,
                         ip=ip_addr,
@@ -212,17 +207,18 @@ class Auth(object):
 
                 return synapse.types.create_requester(user_id, app_service=app_service)
 
-            user_info = yield self.get_user_by_access_token(
+            user_info = await self.get_user_by_access_token(
                 access_token, rights, allow_expired=allow_expired
             )
             user = user_info["user"]
             token_id = user_info["token_id"]
             is_guest = user_info["is_guest"]
+            shadow_banned = user_info["shadow_banned"]
 
             # Deny the request if the user account has expired.
             if self._account_validity.enabled and not allow_expired:
                 user_id = user.to_string()
-                expiration_ts = yield self.store.get_expiration_ts_for_user(user_id)
+                expiration_ts = await self.store.get_expiration_ts_for_user(user_id)
                 if (
                     expiration_ts is not None
                     and self.clock.time_msec() >= expiration_ts
@@ -236,7 +232,7 @@ class Auth(object):
             device_id = user_info.get("device_id")
 
             if user and access_token and ip_addr:
-                yield self.store.insert_client_ip(
+                await self.store.insert_client_ip(
                     user_id=user.to_string(),
                     access_token=access_token,
                     ip=ip_addr,
@@ -257,13 +253,17 @@ class Auth(object):
                 opentracing.set_tag("device_id", device_id)
 
             return synapse.types.create_requester(
-                user, token_id, is_guest, device_id, app_service=app_service
+                user,
+                token_id,
+                is_guest,
+                shadow_banned,
+                device_id,
+                app_service=app_service,
             )
         except KeyError:
             raise MissingClientTokenError()
 
-    @defer.inlineCallbacks
-    def _get_appservice_user_id(self, request):
+    async def _get_appservice_user_id(self, request):
         app_service = self.store.get_app_service_by_token(
             self.get_access_token_from_request(request)
         )
@@ -284,14 +284,13 @@ class Auth(object):
 
         if not app_service.is_interested_in_user(user_id):
             raise AuthError(403, "Application service cannot masquerade as this user.")
-        if not (yield self.store.get_user_by_id(user_id)):
+        if not (await self.store.get_user_by_id(user_id)):
             raise AuthError(403, "Application service has not registered this user")
         return user_id, app_service
 
-    @defer.inlineCallbacks
-    def get_user_by_access_token(
+    async def get_user_by_access_token(
         self, token: str, rights: str = "access", allow_expired: bool = False,
-    ):
+    ) -> dict:
         """ Validate access token and get user_id from it
 
         Args:
@@ -301,9 +300,10 @@ class Auth(object):
             allow_expired: If False, raises an InvalidClientTokenError
                 if the token is expired
         Returns:
-            Deferred[dict]: dict that includes:
+            dict that includes:
                `user` (UserID)
                `is_guest` (bool)
+               `shadow_banned` (bool)
                `token_id` (int|None): access token id. May be None if guest
                `device_id` (str|None): device corresponding to access token
         Raises:
@@ -315,7 +315,7 @@ class Auth(object):
 
         if rights == "access":
             # first look in the database
-            r = yield self._look_up_user_by_access_token(token)
+            r = await self._look_up_user_by_access_token(token)
             if r:
                 valid_until_ms = r["valid_until_ms"]
                 if (
@@ -353,7 +353,7 @@ class Auth(object):
                 # It would of course be much easier to store guest access
                 # tokens in the database as well, but that would break existing
                 # guest tokens.
-                stored_user = yield self.store.get_user_by_id(user_id)
+                stored_user = await self.store.get_user_by_id(user_id)
                 if not stored_user:
                     raise InvalidClientTokenError("Unknown user_id %s" % user_id)
                 if not stored_user["is_guest"]:
@@ -363,6 +363,7 @@ class Auth(object):
                 ret = {
                     "user": user,
                     "is_guest": True,
+                    "shadow_banned": False,
                     "token_id": None,
                     # all guests get the same device id
                     "device_id": GUEST_DEVICE_ID,
@@ -372,6 +373,7 @@ class Auth(object):
                 ret = {
                     "user": user,
                     "is_guest": False,
+                    "shadow_banned": False,
                     "token_id": None,
                     "device_id": None,
                 }
@@ -483,9 +485,8 @@ class Auth(object):
         now = self.hs.get_clock().time_msec()
         return now < expiry
 
-    @defer.inlineCallbacks
-    def _look_up_user_by_access_token(self, token):
-        ret = yield self.store.get_user_by_access_token(token)
+    async def _look_up_user_by_access_token(self, token):
+        ret = await self.store.get_user_by_access_token(token)
         if not ret:
             return None
 
@@ -496,6 +497,7 @@ class Auth(object):
             "user": UserID.from_string(ret.get("name")),
             "token_id": ret.get("token_id", None),
             "is_guest": False,
+            "shadow_banned": ret.get("shadow_banned"),
             "device_id": ret.get("device_id"),
             "valid_until_ms": ret.get("valid_until_ms"),
         }
@@ -508,7 +510,7 @@ class Auth(object):
             logger.warning("Unrecognised appservice access token.")
             raise InvalidClientTokenError()
         request.authenticated_entity = service.sender
-        return defer.succeed(service)
+        return service
 
     async def is_server_admin(self, user: UserID) -> bool:
         """ Check if the given user is a local server admin.
@@ -523,7 +525,7 @@ class Auth(object):
 
     def compute_auth_events(
         self, event, current_state_ids: StateMap[str], for_verification: bool = False,
-    ):
+    ) -> List[str]:
         """Given an event and current state return the list of event IDs used
         to auth an event.
 
@@ -531,16 +533,16 @@ class Auth(object):
         should be added to the event's `auth_events`.
 
         Returns:
-            defer.Deferred(list[str]): List of event IDs.
+            List of event IDs.
         """
 
         if event.type == EventTypes.Create:
-            return defer.succeed([])
+            return []
 
         # Currently we ignore the `for_verification` flag even though there are
         # some situations where we can drop particular auth events when adding
         # to the event's `auth_events` (e.g. joins pointing to previous joins
-        # when room is publically joinable). Dropping event IDs has the
+        # when room is publicly joinable). Dropping event IDs has the
         # advantage that the auth chain for the room grows slower, but we use
         # the auth chain in state resolution v2 to order events, which means
         # care must be taken if dropping events to ensure that it doesn't
@@ -554,7 +556,7 @@ class Auth(object):
             if auth_ev_id:
                 auth_ids.append(auth_ev_id)
 
-        return defer.succeed(auth_ids)
+        return auth_ids
 
     async def check_can_change_room_list(self, room_id: str, user: UserID):
         """Determine whether the user is allowed to edit the room's entry in the
@@ -637,10 +639,9 @@ class Auth(object):
 
             return query_params[0].decode("ascii")
 
-    @defer.inlineCallbacks
-    def check_user_in_room_or_world_readable(
+    async def check_user_in_room_or_world_readable(
         self, room_id: str, user_id: str, allow_departed_users: bool = False
-    ):
+    ) -> Tuple[str, Optional[str]]:
         """Checks that the user is or was in the room or the room is world
         readable. If it isn't then an exception is raised.
 
@@ -651,10 +652,9 @@ class Auth(object):
                 members but have now departed
 
         Returns:
-            Deferred[tuple[str, str|None]]: Resolves to the current membership of
-                the user in the room and the membership event ID of the user. If
-                the user is not in the room and never has been, then
-                `(Membership.JOIN, None)` is returned.
+            Resolves to the current membership of the user in the room and the
+            membership event ID of the user. If the user is not in the room and
+            never has been, then `(Membership.JOIN, None)` is returned.
         """
 
         try:
@@ -663,12 +663,12 @@ class Auth(object):
             #  * The user is a non-guest user, and was ever in the room
             #  * The user is a guest user, and has joined the room
             # else it will throw.
-            member_event = yield self.check_user_in_room(
+            member_event = await self.check_user_in_room(
                 room_id, user_id, allow_departed_users=allow_departed_users
             )
             return member_event.membership, member_event.event_id
         except AuthError:
-            visibility = yield self.state.get_current_state(
+            visibility = await self.state.get_current_state(
                 room_id, EventTypes.RoomHistoryVisibility, ""
             )
             if (
diff --git a/synapse/api/auth_blocking.py b/synapse/api/auth_blocking.py
index 5c499b6b4e..49093bf181 100644
--- a/synapse/api/auth_blocking.py
+++ b/synapse/api/auth_blocking.py
@@ -15,8 +15,6 @@
 
 import logging
 
-from twisted.internet import defer
-
 from synapse.api.constants import LimitBlockingTypes, UserTypes
 from synapse.api.errors import Codes, ResourceLimitError
 from synapse.config.server import is_threepid_reserved
@@ -36,8 +34,7 @@ class AuthBlocking(object):
         self._limit_usage_by_mau = hs.config.limit_usage_by_mau
         self._mau_limits_reserved_threepids = hs.config.mau_limits_reserved_threepids
 
-    @defer.inlineCallbacks
-    def check_auth_blocking(self, user_id=None, threepid=None, user_type=None):
+    async def check_auth_blocking(self, user_id=None, threepid=None, user_type=None):
         """Checks if the user should be rejected for some external reason,
         such as monthly active user limiting or global disable flag
 
@@ -60,7 +57,7 @@ class AuthBlocking(object):
         if user_id is not None:
             if user_id == self._server_notices_mxid:
                 return
-            if (yield self.store.is_support_user(user_id)):
+            if await self.store.is_support_user(user_id):
                 return
 
         if self._hs_disabled:
@@ -76,11 +73,11 @@ class AuthBlocking(object):
 
             # If the user is already part of the MAU cohort or a trial user
             if user_id:
-                timestamp = yield self.store.user_last_seen_monthly_active(user_id)
+                timestamp = await self.store.user_last_seen_monthly_active(user_id)
                 if timestamp:
                     return
 
-                is_trial = yield self.store.is_trial_user(user_id)
+                is_trial = await self.store.is_trial_user(user_id)
                 if is_trial:
                     return
             elif threepid:
@@ -93,7 +90,7 @@ class AuthBlocking(object):
                 # allow registration. Support users are excluded from MAU checks.
                 return
             # Else if there is no room in the MAU bucket, bail
-            current_mau = yield self.store.get_monthly_active_count()
+            current_mau = await self.store.get_monthly_active_count()
             if current_mau >= self._max_mau_value:
                 raise ResourceLimitError(
                     403,
diff --git a/synapse/api/errors.py b/synapse/api/errors.py
index d54dfb385d..4888c0ec4d 100644
--- a/synapse/api/errors.py
+++ b/synapse/api/errors.py
@@ -17,14 +17,16 @@
 """Contains exceptions and error codes."""
 
 import logging
-from typing import Dict, List
+import typing
+from http import HTTPStatus
+from typing import Dict, List, Optional, Union
 
-from six import iteritems
-from six.moves import http_client
+from twisted.web import http
 
-from canonicaljson import json
+from synapse.util import json_decoder
 
-from twisted.web import http
+if typing.TYPE_CHECKING:
+    from synapse.types import JsonDict
 
 logger = logging.getLogger(__name__)
 
@@ -80,11 +82,11 @@ class CodeMessageException(RuntimeError):
     """An exception with integer code and message string attributes.
 
     Attributes:
-        code (int): HTTP error code
-        msg (str): string describing the error
+        code: HTTP error code
+        msg: string describing the error
     """
 
-    def __init__(self, code, msg):
+    def __init__(self, code: Union[int, HTTPStatus], msg: str):
         super(CodeMessageException, self).__init__("%d: %s" % (code, msg))
 
         # Some calls to this method pass instances of http.HTTPStatus for `code`.
@@ -125,16 +127,16 @@ class SynapseError(CodeMessageException):
     message (as well as an HTTP status code).
 
     Attributes:
-        errcode (str): Matrix error code e.g 'M_FORBIDDEN'
+        errcode: Matrix error code e.g 'M_FORBIDDEN'
     """
 
-    def __init__(self, code, msg, errcode=Codes.UNKNOWN):
+    def __init__(self, code: int, msg: str, errcode: str = Codes.UNKNOWN):
         """Constructs a synapse error.
 
         Args:
-            code (int): The integer error code (an HTTP response code)
-            msg (str): The human-readable error message.
-            errcode (str): The matrix error code e.g 'M_FORBIDDEN'
+            code: The integer error code (an HTTP response code)
+            msg: The human-readable error message.
+            errcode: The matrix error code e.g 'M_FORBIDDEN'
         """
         super(SynapseError, self).__init__(code, msg)
         self.errcode = errcode
@@ -147,10 +149,16 @@ class ProxiedRequestError(SynapseError):
     """An error from a general matrix endpoint, eg. from a proxied Matrix API call.
 
     Attributes:
-        errcode (str): Matrix error code e.g 'M_FORBIDDEN'
+        errcode: Matrix error code e.g 'M_FORBIDDEN'
     """
 
-    def __init__(self, code, msg, errcode=Codes.UNKNOWN, additional_fields=None):
+    def __init__(
+        self,
+        code: int,
+        msg: str,
+        errcode: str = Codes.UNKNOWN,
+        additional_fields: Optional[Dict] = None,
+    ):
         super(ProxiedRequestError, self).__init__(code, msg, errcode)
         if additional_fields is None:
             self._additional_fields = {}  # type: Dict
@@ -166,15 +174,15 @@ class ConsentNotGivenError(SynapseError):
     privacy policy.
     """
 
-    def __init__(self, msg, consent_uri):
+    def __init__(self, msg: str, consent_uri: str):
         """Constructs a ConsentNotGivenError
 
         Args:
-            msg (str): The human-readable error message
-            consent_url (str): The URL where the user can give their consent
+            msg: The human-readable error message
+            consent_url: The URL where the user can give their consent
         """
         super(ConsentNotGivenError, self).__init__(
-            code=http_client.FORBIDDEN, msg=msg, errcode=Codes.CONSENT_NOT_GIVEN
+            code=HTTPStatus.FORBIDDEN, msg=msg, errcode=Codes.CONSENT_NOT_GIVEN
         )
         self._consent_uri = consent_uri
 
@@ -187,14 +195,14 @@ class UserDeactivatedError(SynapseError):
     authenticated endpoint, but the account has been deactivated.
     """
 
-    def __init__(self, msg):
+    def __init__(self, msg: str):
         """Constructs a UserDeactivatedError
 
         Args:
-            msg (str): The human-readable error message
+            msg: The human-readable error message
         """
         super(UserDeactivatedError, self).__init__(
-            code=http_client.FORBIDDEN, msg=msg, errcode=Codes.USER_DEACTIVATED
+            code=HTTPStatus.FORBIDDEN, msg=msg, errcode=Codes.USER_DEACTIVATED
         )
 
 
@@ -203,16 +211,16 @@ class FederationDeniedError(SynapseError):
     is not on its federation whitelist.
 
     Attributes:
-        destination (str): The destination which has been denied
+        destination: The destination which has been denied
     """
 
-    def __init__(self, destination):
+    def __init__(self, destination: Optional[str]):
         """Raised by federation client or server to indicate that we are
         are deliberately not attempting to contact a given server because it is
         not on our federation whitelist.
 
         Args:
-            destination (str): the domain in question
+            destination: the domain in question
         """
 
         self.destination = destination
@@ -230,14 +238,16 @@ class InteractiveAuthIncompleteError(Exception):
     (This indicates we should return a 401 with 'result' as the body)
 
     Attributes:
-        result (dict): the server response to the request, which should be
+        session_id: The ID of the ongoing interactive auth session.
+        result: the server response to the request, which should be
             passed back to the client
     """
 
-    def __init__(self, result):
+    def __init__(self, session_id: str, result: "JsonDict"):
         super(InteractiveAuthIncompleteError, self).__init__(
             "Interactive auth not yet complete"
         )
+        self.session_id = session_id
         self.result = result
 
 
@@ -247,7 +257,6 @@ class UnrecognizedRequestError(SynapseError):
     def __init__(self, *args, **kwargs):
         if "errcode" not in kwargs:
             kwargs["errcode"] = Codes.UNRECOGNIZED
-        message = None
         if len(args) == 0:
             message = "Unrecognized request"
         else:
@@ -258,7 +267,7 @@ class UnrecognizedRequestError(SynapseError):
 class NotFoundError(SynapseError):
     """An error indicating we can't find the thing you asked for"""
 
-    def __init__(self, msg="Not found", errcode=Codes.NOT_FOUND):
+    def __init__(self, msg: str = "Not found", errcode: str = Codes.NOT_FOUND):
         super(NotFoundError, self).__init__(404, msg, errcode=errcode)
 
 
@@ -284,21 +293,23 @@ class InvalidClientCredentialsError(SynapseError):
     M_UNKNOWN_TOKEN respectively.
     """
 
-    def __init__(self, msg, errcode):
+    def __init__(self, msg: str, errcode: str):
         super().__init__(code=401, msg=msg, errcode=errcode)
 
 
 class MissingClientTokenError(InvalidClientCredentialsError):
     """Raised when we couldn't find the access token in a request"""
 
-    def __init__(self, msg="Missing access token"):
+    def __init__(self, msg: str = "Missing access token"):
         super().__init__(msg=msg, errcode="M_MISSING_TOKEN")
 
 
 class InvalidClientTokenError(InvalidClientCredentialsError):
     """Raised when we didn't understand the access token in a request"""
 
-    def __init__(self, msg="Unrecognised access token", soft_logout=False):
+    def __init__(
+        self, msg: str = "Unrecognised access token", soft_logout: bool = False
+    ):
         super().__init__(msg=msg, errcode="M_UNKNOWN_TOKEN")
         self._soft_logout = soft_logout
 
@@ -316,11 +327,11 @@ class ResourceLimitError(SynapseError):
 
     def __init__(
         self,
-        code,
-        msg,
-        errcode=Codes.RESOURCE_LIMIT_EXCEEDED,
-        admin_contact=None,
-        limit_type=None,
+        code: int,
+        msg: str,
+        errcode: str = Codes.RESOURCE_LIMIT_EXCEEDED,
+        admin_contact: Optional[str] = None,
+        limit_type: Optional[str] = None,
     ):
         self.admin_contact = admin_contact
         self.limit_type = limit_type
@@ -368,10 +379,10 @@ class StoreError(SynapseError):
 class InvalidCaptchaError(SynapseError):
     def __init__(
         self,
-        code=400,
-        msg="Invalid captcha.",
-        error_url=None,
-        errcode=Codes.CAPTCHA_INVALID,
+        code: int = 400,
+        msg: str = "Invalid captcha.",
+        error_url: Optional[str] = None,
+        errcode: str = Codes.CAPTCHA_INVALID,
     ):
         super(InvalidCaptchaError, self).__init__(code, msg, errcode)
         self.error_url = error_url
@@ -386,10 +397,10 @@ class LimitExceededError(SynapseError):
 
     def __init__(
         self,
-        code=429,
-        msg="Too Many Requests",
-        retry_after_ms=None,
-        errcode=Codes.LIMIT_EXCEEDED,
+        code: int = 429,
+        msg: str = "Too Many Requests",
+        retry_after_ms: Optional[int] = None,
+        errcode: str = Codes.LIMIT_EXCEEDED,
     ):
         super(LimitExceededError, self).__init__(code, msg, errcode)
         self.retry_after_ms = retry_after_ms
@@ -402,10 +413,10 @@ class RoomKeysVersionError(SynapseError):
     """A client has tried to upload to a non-current version of the room_keys store
     """
 
-    def __init__(self, current_version):
+    def __init__(self, current_version: str):
         """
         Args:
-            current_version (str): the current version of the store they should have used
+            current_version: the current version of the store they should have used
         """
         super(RoomKeysVersionError, self).__init__(
             403, "Wrong room_keys version", Codes.WRONG_ROOM_KEYS_VERSION
@@ -417,7 +428,7 @@ class UnsupportedRoomVersionError(SynapseError):
     """The client's request to create a room used a room version that the server does
     not support."""
 
-    def __init__(self, msg="Homeserver does not support this room version"):
+    def __init__(self, msg: str = "Homeserver does not support this room version"):
         super(UnsupportedRoomVersionError, self).__init__(
             code=400, msg=msg, errcode=Codes.UNSUPPORTED_ROOM_VERSION,
         )
@@ -439,7 +450,7 @@ class IncompatibleRoomVersionError(SynapseError):
     failing.
     """
 
-    def __init__(self, room_version):
+    def __init__(self, room_version: str):
         super(IncompatibleRoomVersionError, self).__init__(
             code=400,
             msg="Your homeserver does not support the features required to "
@@ -459,8 +470,8 @@ class PasswordRefusedError(SynapseError):
 
     def __init__(
         self,
-        msg="This password doesn't comply with the server's policy",
-        errcode=Codes.WEAK_PASSWORD,
+        msg: str = "This password doesn't comply with the server's policy",
+        errcode: str = Codes.WEAK_PASSWORD,
     ):
         super(PasswordRefusedError, self).__init__(
             code=400, msg=msg, errcode=errcode,
@@ -485,19 +496,19 @@ class RequestSendFailed(RuntimeError):
         self.can_retry = can_retry
 
 
-def cs_error(msg, code=Codes.UNKNOWN, **kwargs):
+def cs_error(msg: str, code: str = Codes.UNKNOWN, **kwargs):
     """ Utility method for constructing an error response for client-server
     interactions.
 
     Args:
-        msg (str): The error message.
-        code (str): The error code.
-        kwargs : Additional keys to add to the response.
+        msg: The error message.
+        code: The error code.
+        kwargs: Additional keys to add to the response.
     Returns:
         A dict representing the error response JSON.
     """
     err = {"error": msg, "errcode": code}
-    for key, value in iteritems(kwargs):
+    for key, value in kwargs.items():
         err[key] = value
     return err
 
@@ -514,7 +525,14 @@ class FederationError(RuntimeError):
         is wrong (e.g., it referred to an invalid event)
     """
 
-    def __init__(self, level, code, reason, affected, source=None):
+    def __init__(
+        self,
+        level: str,
+        code: int,
+        reason: str,
+        affected: str,
+        source: Optional[str] = None,
+    ):
         if level not in ["FATAL", "ERROR", "WARN"]:
             raise ValueError("Level is not valid: %s" % (level,))
         self.level = level
@@ -541,16 +559,16 @@ class HttpResponseException(CodeMessageException):
     Represents an HTTP-level failure of an outbound request
 
     Attributes:
-        response (bytes): body of response
+        response: body of response
     """
 
-    def __init__(self, code, msg, response):
+    def __init__(self, code: int, msg: str, response: bytes):
         """
 
         Args:
-            code (int): HTTP status code
-            msg (str): reason phrase from HTTP response status line
-            response (bytes): body of response
+            code: HTTP status code
+            msg: reason phrase from HTTP response status line
+            response: body of response
         """
         super(HttpResponseException, self).__init__(code, msg)
         self.response = response
@@ -575,7 +593,7 @@ class HttpResponseException(CodeMessageException):
         # try to parse the body as json, to get better errcode/msg, but
         # default to M_UNKNOWN with the HTTP status as the error text
         try:
-            j = json.loads(self.response)
+            j = json_decoder.decode(self.response.decode("utf-8"))
         except ValueError:
             j = {}
 
@@ -586,3 +604,11 @@ class HttpResponseException(CodeMessageException):
         errmsg = j.pop("error", self.msg)
 
         return ProxiedRequestError(self.code, errmsg, errcode, j)
+
+
+class ShadowBanError(Exception):
+    """
+    Raised when a shadow-banned user attempts to perform an action.
+
+    This should be caught and a proper "fake" success response sent to the user.
+    """
diff --git a/synapse/api/filtering.py b/synapse/api/filtering.py
index 8b64d0a285..a8937d2595 100644
--- a/synapse/api/filtering.py
+++ b/synapse/api/filtering.py
@@ -17,17 +17,13 @@
 # limitations under the License.
 from typing import List
 
-from six import text_type
-
 import jsonschema
 from canonicaljson import json
 from jsonschema import FormatChecker
 
-from twisted.internet import defer
-
 from synapse.api.constants import EventContentFields
 from synapse.api.errors import SynapseError
-from synapse.storage.presence import UserPresenceState
+from synapse.api.presence import UserPresenceState
 from synapse.types import RoomID, UserID
 
 FILTER_SCHEMA = {
@@ -139,9 +135,8 @@ class Filtering(object):
         super(Filtering, self).__init__()
         self.store = hs.get_datastore()
 
-    @defer.inlineCallbacks
-    def get_user_filter(self, user_localpart, filter_id):
-        result = yield self.store.get_user_filter(user_localpart, filter_id)
+    async def get_user_filter(self, user_localpart, filter_id):
+        result = await self.store.get_user_filter(user_localpart, filter_id)
         return FilterCollection(result)
 
     def add_user_filter(self, user_localpart, user_filter):
@@ -313,7 +308,7 @@ class Filter(object):
 
             content = event.get("content", {})
             # check if there is a string url field in the content for filtering purposes
-            contains_url = isinstance(content.get("url"), text_type)
+            contains_url = isinstance(content.get("url"), str)
             labels = content.get(EventContentFields.LABELS, [])
 
         return self.check_fields(room_id, sender, ev_type, labels, contains_url)
diff --git a/synapse/api/presence.py b/synapse/api/presence.py
new file mode 100644
index 0000000000..18a462f0ee
--- /dev/null
+++ b/synapse/api/presence.py
@@ -0,0 +1,69 @@
+# -*- coding: utf-8 -*-
+# Copyright 2014-2016 OpenMarket 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.
+
+from collections import namedtuple
+
+from synapse.api.constants import PresenceState
+
+
+class UserPresenceState(
+    namedtuple(
+        "UserPresenceState",
+        (
+            "user_id",
+            "state",
+            "last_active_ts",
+            "last_federation_update_ts",
+            "last_user_sync_ts",
+            "status_msg",
+            "currently_active",
+        ),
+    )
+):
+    """Represents the current presence state of the user.
+
+    user_id (str)
+    last_active (int): Time in msec that the user last interacted with server.
+    last_federation_update (int): Time in msec since either a) we sent a presence
+        update to other servers or b) we received a presence update, depending
+        on if is a local user or not.
+    last_user_sync (int): Time in msec that the user last *completed* a sync
+        (or event stream).
+    status_msg (str): User set status message.
+    """
+
+    def as_dict(self):
+        return dict(self._asdict())
+
+    @staticmethod
+    def from_dict(d):
+        return UserPresenceState(**d)
+
+    def copy_and_replace(self, **kwargs):
+        return self._replace(**kwargs)
+
+    @classmethod
+    def default(cls, user_id):
+        """Returns a default presence state.
+        """
+        return cls(
+            user_id=user_id,
+            state=PresenceState.OFFLINE,
+            last_active_ts=0,
+            last_federation_update_ts=0,
+            last_user_sync_ts=0,
+            status_msg=None,
+            currently_active=False,
+        )
diff --git a/synapse/api/ratelimiting.py b/synapse/api/ratelimiting.py
index ec6b3a69a2..e62ae50ac2 100644
--- a/synapse/api/ratelimiting.py
+++ b/synapse/api/ratelimiting.py
@@ -17,6 +17,7 @@ from collections import OrderedDict
 from typing import Any, Optional, Tuple
 
 from synapse.api.errors import LimitExceededError
+from synapse.types import Requester
 from synapse.util import Clock
 
 
@@ -43,6 +44,42 @@ class Ratelimiter(object):
         #   * The rate_hz of this particular entry. This can vary per request
         self.actions = OrderedDict()  # type: OrderedDict[Any, Tuple[float, int, float]]
 
+    def can_requester_do_action(
+        self,
+        requester: Requester,
+        rate_hz: Optional[float] = None,
+        burst_count: Optional[int] = None,
+        update: bool = True,
+        _time_now_s: Optional[int] = None,
+    ) -> Tuple[bool, float]:
+        """Can the requester perform the action?
+
+        Args:
+            requester: The requester to key off when rate limiting. The user property
+                will be used.
+            rate_hz: The long term number of actions that can be performed in a second.
+                Overrides the value set during instantiation if set.
+            burst_count: How many actions that can be performed before being limited.
+                Overrides the value set during instantiation if set.
+            update: Whether to count this check as performing the action
+            _time_now_s: The current time. Optional, defaults to the current time according
+                to self.clock. Only used by tests.
+
+        Returns:
+            A tuple containing:
+                * A bool indicating if they can perform the action now
+                * The reactor timestamp for when the action can be performed next.
+                  -1 if rate_hz is less than or equal to zero
+        """
+        # Disable rate limiting of users belonging to any AS that is configured
+        # not to be rate limited in its registration file (rate_limited: true|false).
+        if requester.app_service and not requester.app_service.is_rate_limited():
+            return True, -1.0
+
+        return self.can_do_action(
+            requester.user.to_string(), rate_hz, burst_count, update, _time_now_s
+        )
+
     def can_do_action(
         self,
         key: Any,
diff --git a/synapse/api/urls.py b/synapse/api/urls.py
index f34434bd67..bd03ebca5a 100644
--- a/synapse/api/urls.py
+++ b/synapse/api/urls.py
@@ -17,8 +17,7 @@
 """Contains the URL paths to prefix various aspects of the server with. """
 import hmac
 from hashlib import sha256
-
-from six.moves.urllib.parse import urlencode
+from urllib.parse import urlencode
 
 from synapse.config import ConfigError