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-rw-r--r--synapse/app/frontend_proxy.py10
-rwxr-xr-xsynapse/app/homeserver.py120
-rw-r--r--synapse/appservice/api.py10
-rw-r--r--synapse/config/cas.py2
-rw-r--r--synapse/config/logger.py6
-rw-r--r--synapse/config/password_auth_providers.py39
-rw-r--r--synapse/config/server.py7
-rw-r--r--synapse/config/tls.py6
-rw-r--r--synapse/federation/federation_server.py8
-rw-r--r--synapse/federation/transport/client.py9
-rw-r--r--synapse/federation/transport/server.py4
-rw-r--r--synapse/groups/attestations.py54
-rw-r--r--synapse/groups/groups_server.py183
-rw-r--r--synapse/handlers/auth.py273
-rw-r--r--synapse/handlers/device.py7
-rw-r--r--synapse/handlers/groups_local.py4
-rw-r--r--synapse/handlers/register.py3
-rw-r--r--synapse/handlers/room_list.py9
-rw-r--r--synapse/handlers/sync.py6
-rw-r--r--synapse/http/additional_resource.py55
-rw-r--r--synapse/http/client.py127
-rw-r--r--synapse/module_api/__init__.py113
-rw-r--r--synapse/rest/client/v1/admin.py9
-rw-r--r--synapse/rest/client/v1/login.py71
-rw-r--r--synapse/rest/client/v1/logout.py8
-rw-r--r--synapse/rest/client/v2_alpha/account.py47
-rw-r--r--synapse/rest/client/v2_alpha/devices.py20
-rw-r--r--synapse/rest/client/v2_alpha/groups.py97
-rw-r--r--synapse/rest/client/v2_alpha/keys.py18
-rw-r--r--synapse/rest/client/v2_alpha/notifications.py2
-rw-r--r--synapse/rest/client/v2_alpha/register.py29
-rw-r--r--synapse/rest/client/v2_alpha/sendtodevice.py2
-rw-r--r--synapse/rest/client/v2_alpha/thirdparty.py11
-rw-r--r--synapse/rest/media/v1/preview_url_resource.py9
-rw-r--r--synapse/storage/group_server.py45
-rw-r--r--synapse/storage/prepare_database.py72
-rw-r--r--synapse/storage/registration.py48
-rw-r--r--synapse/storage/schema/delta/23/refresh_tokens.sql21
-rw-r--r--synapse/storage/schema/delta/33/refreshtoken_device_index.sql17
-rw-r--r--synapse/storage/schema/delta/46/drop_refresh_tokens.sql (renamed from synapse/storage/schema/delta/33/refreshtoken_device.sql)5
-rw-r--r--synapse/storage/schema/delta/46/group_server.sql32
-rw-r--r--synapse/storage/schema/schema_version.sql7
-rw-r--r--synapse/util/async.py24
43 files changed, 1135 insertions, 514 deletions
diff --git a/synapse/app/frontend_proxy.py b/synapse/app/frontend_proxy.py
index bee4c47498..abc7ef5725 100644
--- a/synapse/app/frontend_proxy.py
+++ b/synapse/app/frontend_proxy.py
@@ -50,8 +50,7 @@ logger = logging.getLogger("synapse.app.frontend_proxy")
 
 
 class KeyUploadServlet(RestServlet):
-    PATTERNS = client_v2_patterns("/keys/upload(/(?P<device_id>[^/]+))?$",
-                                  releases=())
+    PATTERNS = client_v2_patterns("/keys/upload(/(?P<device_id>[^/]+))?$")
 
     def __init__(self, hs):
         """
@@ -89,9 +88,16 @@ class KeyUploadServlet(RestServlet):
 
         if body:
             # They're actually trying to upload something, proxy to main synapse.
+            # Pass through the auth headers, if any, in case the access token
+            # is there.
+            auth_headers = request.requestHeaders.getRawHeaders("Authorization", [])
+            headers = {
+                "Authorization": auth_headers,
+            }
             result = yield self.http_client.post_json_get_json(
                 self.main_uri + request.uri,
                 body,
+                headers=headers,
             )
 
             defer.returnValue((200, result))
diff --git a/synapse/app/homeserver.py b/synapse/app/homeserver.py
index 3adf72e141..9e26146338 100755
--- a/synapse/app/homeserver.py
+++ b/synapse/app/homeserver.py
@@ -30,6 +30,8 @@ from synapse.config._base import ConfigError
 from synapse.config.homeserver import HomeServerConfig
 from synapse.crypto import context_factory
 from synapse.federation.transport.server import TransportLayerServer
+from synapse.module_api import ModuleApi
+from synapse.http.additional_resource import AdditionalResource
 from synapse.http.server import RootRedirect
 from synapse.http.site import SynapseSite
 from synapse.metrics import register_memory_metrics
@@ -49,6 +51,7 @@ from synapse.storage.prepare_database import UpgradeDatabaseException, prepare_d
 from synapse.util.httpresourcetree import create_resource_tree
 from synapse.util.logcontext import LoggingContext
 from synapse.util.manhole import manhole
+from synapse.util.module_loader import load_module
 from synapse.util.rlimit import change_resource_limit
 from synapse.util.versionstring import get_version_string
 from twisted.application import service
@@ -107,52 +110,18 @@ class SynapseHomeServer(HomeServer):
         resources = {}
         for res in listener_config["resources"]:
             for name in res["names"]:
-                if name == "client":
-                    client_resource = ClientRestResource(self)
-                    if res["compress"]:
-                        client_resource = gz_wrap(client_resource)
-
-                    resources.update({
-                        "/_matrix/client/api/v1": client_resource,
-                        "/_matrix/client/r0": client_resource,
-                        "/_matrix/client/unstable": client_resource,
-                        "/_matrix/client/v2_alpha": client_resource,
-                        "/_matrix/client/versions": client_resource,
-                    })
-
-                if name == "federation":
-                    resources.update({
-                        FEDERATION_PREFIX: TransportLayerServer(self),
-                    })
-
-                if name in ["static", "client"]:
-                    resources.update({
-                        STATIC_PREFIX: File(
-                            os.path.join(os.path.dirname(synapse.__file__), "static")
-                        ),
-                    })
-
-                if name in ["media", "federation", "client"]:
-                    media_repo = MediaRepositoryResource(self)
-                    resources.update({
-                        MEDIA_PREFIX: media_repo,
-                        LEGACY_MEDIA_PREFIX: media_repo,
-                        CONTENT_REPO_PREFIX: ContentRepoResource(
-                            self, self.config.uploads_path
-                        ),
-                    })
-
-                if name in ["keys", "federation"]:
-                    resources.update({
-                        SERVER_KEY_PREFIX: LocalKey(self),
-                        SERVER_KEY_V2_PREFIX: KeyApiV2Resource(self),
-                    })
-
-                if name == "webclient":
-                    resources[WEB_CLIENT_PREFIX] = build_resource_for_web_client(self)
+                resources.update(self._configure_named_resource(
+                    name, res.get("compress", False),
+                ))
 
-                if name == "metrics" and self.get_config().enable_metrics:
-                    resources[METRICS_PREFIX] = MetricsResource(self)
+        additional_resources = listener_config.get("additional_resources", {})
+        logger.debug("Configuring additional resources: %r",
+                     additional_resources)
+        module_api = ModuleApi(self, self.get_auth_handler())
+        for path, resmodule in additional_resources.items():
+            handler_cls, config = load_module(resmodule)
+            handler = handler_cls(config, module_api)
+            resources[path] = AdditionalResource(self, handler.handle_request)
 
         if WEB_CLIENT_PREFIX in resources:
             root_resource = RootRedirect(WEB_CLIENT_PREFIX)
@@ -188,6 +157,67 @@ class SynapseHomeServer(HomeServer):
                 )
         logger.info("Synapse now listening on port %d", port)
 
+    def _configure_named_resource(self, name, compress=False):
+        """Build a resource map for a named resource
+
+        Args:
+            name (str): named resource: one of "client", "federation", etc
+            compress (bool): whether to enable gzip compression for this
+                resource
+
+        Returns:
+            dict[str, Resource]: map from path to HTTP resource
+        """
+        resources = {}
+        if name == "client":
+            client_resource = ClientRestResource(self)
+            if compress:
+                client_resource = gz_wrap(client_resource)
+
+            resources.update({
+                "/_matrix/client/api/v1": client_resource,
+                "/_matrix/client/r0": client_resource,
+                "/_matrix/client/unstable": client_resource,
+                "/_matrix/client/v2_alpha": client_resource,
+                "/_matrix/client/versions": client_resource,
+            })
+
+        if name == "federation":
+            resources.update({
+                FEDERATION_PREFIX: TransportLayerServer(self),
+            })
+
+        if name in ["static", "client"]:
+            resources.update({
+                STATIC_PREFIX: File(
+                    os.path.join(os.path.dirname(synapse.__file__), "static")
+                ),
+            })
+
+        if name in ["media", "federation", "client"]:
+            media_repo = MediaRepositoryResource(self)
+            resources.update({
+                MEDIA_PREFIX: media_repo,
+                LEGACY_MEDIA_PREFIX: media_repo,
+                CONTENT_REPO_PREFIX: ContentRepoResource(
+                    self, self.config.uploads_path
+                ),
+            })
+
+        if name in ["keys", "federation"]:
+            resources.update({
+                SERVER_KEY_PREFIX: LocalKey(self),
+                SERVER_KEY_V2_PREFIX: KeyApiV2Resource(self),
+            })
+
+        if name == "webclient":
+            resources[WEB_CLIENT_PREFIX] = build_resource_for_web_client(self)
+
+        if name == "metrics" and self.get_config().enable_metrics:
+            resources[METRICS_PREFIX] = MetricsResource(self)
+
+        return resources
+
     def start_listening(self):
         config = self.get_config()
 
diff --git a/synapse/appservice/api.py b/synapse/appservice/api.py
index 6893610e71..40c433d7ae 100644
--- a/synapse/appservice/api.py
+++ b/synapse/appservice/api.py
@@ -18,6 +18,7 @@ from synapse.api.constants import ThirdPartyEntityKind
 from synapse.api.errors import CodeMessageException
 from synapse.http.client import SimpleHttpClient
 from synapse.events.utils import serialize_event
+from synapse.util.logcontext import preserve_fn, make_deferred_yieldable
 from synapse.util.caches.response_cache import ResponseCache
 from synapse.types import ThirdPartyInstanceID
 
@@ -192,9 +193,12 @@ class ApplicationServiceApi(SimpleHttpClient):
                 defer.returnValue(None)
 
         key = (service.id, protocol)
-        return self.protocol_meta_cache.get(key) or (
-            self.protocol_meta_cache.set(key, _get())
-        )
+        result = self.protocol_meta_cache.get(key)
+        if not result:
+            result = self.protocol_meta_cache.set(
+                key, preserve_fn(_get)()
+            )
+        return make_deferred_yieldable(result)
 
     @defer.inlineCallbacks
     def push_bulk(self, service, events, txn_id=None):
diff --git a/synapse/config/cas.py b/synapse/config/cas.py
index 938f6f25f8..8109e5f95e 100644
--- a/synapse/config/cas.py
+++ b/synapse/config/cas.py
@@ -41,7 +41,7 @@ class CasConfig(Config):
         #cas_config:
         #   enabled: true
         #   server_url: "https://cas-server.com"
-        #   service_url: "https://homesever.domain.com:8448"
+        #   service_url: "https://homeserver.domain.com:8448"
         #   #required_attributes:
         #   #    name: value
         """
diff --git a/synapse/config/logger.py b/synapse/config/logger.py
index 2dbeafa9dd..a1d6e4d4f7 100644
--- a/synapse/config/logger.py
+++ b/synapse/config/logger.py
@@ -148,8 +148,8 @@ def setup_logging(config, use_worker_options=False):
         "%(asctime)s - %(name)s - %(lineno)d - %(levelname)s - %(request)s"
         " - %(message)s"
     )
-    if log_config is None:
 
+    if log_config is None:
         level = logging.INFO
         level_for_storage = logging.INFO
         if config.verbosity:
@@ -176,6 +176,10 @@ def setup_logging(config, use_worker_options=False):
                 logger.info("Opened new log file due to SIGHUP")
         else:
             handler = logging.StreamHandler()
+
+            def sighup(signum, stack):
+                pass
+
         handler.setFormatter(formatter)
 
         handler.addFilter(LoggingContextFilter(request=""))
diff --git a/synapse/config/password_auth_providers.py b/synapse/config/password_auth_providers.py
index 90824cab7f..e9828fac17 100644
--- a/synapse/config/password_auth_providers.py
+++ b/synapse/config/password_auth_providers.py
@@ -13,41 +13,40 @@
 # See the License for the specific language governing permissions and
 # limitations under the License.
 
-from ._base import Config, ConfigError
+from ._base import Config
 
 from synapse.util.module_loader import load_module
 
+LDAP_PROVIDER = 'ldap_auth_provider.LdapAuthProvider'
+
 
 class PasswordAuthProviderConfig(Config):
     def read_config(self, config):
         self.password_providers = []
-
-        provider_config = None
+        providers = []
 
         # We want to be backwards compatible with the old `ldap_config`
         # param.
         ldap_config = config.get("ldap_config", {})
-        self.ldap_enabled = ldap_config.get("enabled", False)
-        if self.ldap_enabled:
-            from ldap_auth_provider import LdapAuthProvider
-            parsed_config = LdapAuthProvider.parse_config(ldap_config)
-            self.password_providers.append((LdapAuthProvider, parsed_config))
+        if ldap_config.get("enabled", False):
+            providers.append[{
+                'module': LDAP_PROVIDER,
+                'config': ldap_config,
+            }]
 
-        providers = config.get("password_providers", [])
+        providers.extend(config.get("password_providers", []))
         for provider in providers:
+            mod_name = provider['module']
+
             # This is for backwards compat when the ldap auth provider resided
             # in this package.
-            if provider['module'] == "synapse.util.ldap_auth_provider.LdapAuthProvider":
-                from ldap_auth_provider import LdapAuthProvider
-                provider_class = LdapAuthProvider
-                try:
-                    provider_config = provider_class.parse_config(provider["config"])
-                except Exception as e:
-                    raise ConfigError(
-                        "Failed to parse config for %r: %r" % (provider['module'], e)
-                    )
-            else:
-                (provider_class, provider_config) = load_module(provider)
+            if mod_name == "synapse.util.ldap_auth_provider.LdapAuthProvider":
+                mod_name = LDAP_PROVIDER
+
+            (provider_class, provider_config) = load_module({
+                "module": mod_name,
+                "config": provider['config'],
+            })
 
             self.password_providers.append((provider_class, provider_config))
 
diff --git a/synapse/config/server.py b/synapse/config/server.py
index b66993dab9..4d9193536d 100644
--- a/synapse/config/server.py
+++ b/synapse/config/server.py
@@ -247,6 +247,13 @@ class ServerConfig(Config):
               - names: [federation]  # Federation APIs
                 compress: false
 
+            # optional list of additional endpoints which can be loaded via
+            # dynamic modules
+            # additional_resources:
+            #   "/_matrix/my/custom/endpoint":
+            #     module: my_module.CustomRequestHandler
+            #     config: {}
+
           # Unsecure HTTP listener,
           # For when matrix traffic passes through loadbalancer that unwraps TLS.
           - port: %(unsecure_port)s
diff --git a/synapse/config/tls.py b/synapse/config/tls.py
index 247f18f454..4748f71c2f 100644
--- a/synapse/config/tls.py
+++ b/synapse/config/tls.py
@@ -109,6 +109,12 @@ class TlsConfig(Config):
         # key. It may be necessary to publish the fingerprints of a new
         # certificate and wait until the "valid_until_ts" of the previous key
         # responses have passed before deploying it.
+        #
+        # You can calculate a fingerprint from a given TLS listener via:
+        # openssl s_client -connect $host:$port < /dev/null 2> /dev/null |
+        #   openssl x509 -outform DER | openssl sha256 -binary | base64 | tr -d '='
+        # or by checking matrix.org/federationtester/api/report?server_name=$host
+        #
         tls_fingerprints: []
         # tls_fingerprints: [{"sha256": "<base64_encoded_sha256_fingerprint>"}]
         """ % locals()
diff --git a/synapse/federation/federation_server.py b/synapse/federation/federation_server.py
index e15228e70b..a2327f24b6 100644
--- a/synapse/federation/federation_server.py
+++ b/synapse/federation/federation_server.py
@@ -18,6 +18,7 @@ from .federation_base import FederationBase
 from .units import Transaction, Edu
 
 from synapse.util import async
+from synapse.util.logcontext import make_deferred_yieldable, preserve_fn
 from synapse.util.logutils import log_function
 from synapse.util.caches.response_cache import ResponseCache
 from synapse.events import FrozenEvent
@@ -253,12 +254,13 @@ class FederationServer(FederationBase):
         result = self._state_resp_cache.get((room_id, event_id))
         if not result:
             with (yield self._server_linearizer.queue((origin, room_id))):
-                resp = yield self._state_resp_cache.set(
+                d = self._state_resp_cache.set(
                     (room_id, event_id),
-                    self._on_context_state_request_compute(room_id, event_id)
+                    preserve_fn(self._on_context_state_request_compute)(room_id, event_id)
                 )
+                resp = yield make_deferred_yieldable(d)
         else:
-            resp = yield result
+            resp = yield make_deferred_yieldable(result)
 
         defer.returnValue((200, resp))
 
diff --git a/synapse/federation/transport/client.py b/synapse/federation/transport/client.py
index d25ae1b282..ed41dfc7ee 100644
--- a/synapse/federation/transport/client.py
+++ b/synapse/federation/transport/client.py
@@ -531,9 +531,9 @@ class TransportLayerClient(object):
             ignore_backoff=True,
         )
 
-    def add_room_to_group(self, destination, group_id, requester_user_id, room_id,
-                          content):
-        """Add a room to a group
+    def update_room_group_association(self, destination, group_id, requester_user_id,
+                                      room_id, content):
+        """Add or update an association between room and group
         """
         path = PREFIX + "/groups/%s/room/%s" % (group_id, room_id,)
 
@@ -545,7 +545,8 @@ class TransportLayerClient(object):
             ignore_backoff=True,
         )
 
-    def remove_room_from_group(self, destination, group_id, requester_user_id, room_id):
+    def delete_room_group_association(self, destination, group_id, requester_user_id,
+                                      room_id):
         """Remove a room from a group
         """
         path = PREFIX + "/groups/%s/room/%s" % (group_id, room_id,)
diff --git a/synapse/federation/transport/server.py b/synapse/federation/transport/server.py
index 8f3c14c303..ded6d4edc9 100644
--- a/synapse/federation/transport/server.py
+++ b/synapse/federation/transport/server.py
@@ -684,7 +684,7 @@ class FederationGroupsAddRoomsServlet(BaseFederationServlet):
         if get_domain_from_id(requester_user_id) != origin:
             raise SynapseError(403, "requester_user_id doesn't match origin")
 
-        new_content = yield self.handler.add_room_to_group(
+        new_content = yield self.handler.update_room_group_association(
             group_id, requester_user_id, room_id, content
         )
 
@@ -696,7 +696,7 @@ class FederationGroupsAddRoomsServlet(BaseFederationServlet):
         if get_domain_from_id(requester_user_id) != origin:
             raise SynapseError(403, "requester_user_id doesn't match origin")
 
-        new_content = yield self.handler.remove_room_from_group(
+        new_content = yield self.handler.delete_room_group_association(
             group_id, requester_user_id, room_id,
         )
 
diff --git a/synapse/groups/attestations.py b/synapse/groups/attestations.py
index b751cf5e43..1fb709e6c3 100644
--- a/synapse/groups/attestations.py
+++ b/synapse/groups/attestations.py
@@ -13,6 +13,31 @@
 # See the License for the specific language governing permissions and
 # limitations under the License.
 
+"""Attestations ensure that users and groups can't lie about their memberships.
+
+When a user joins a group the HS and GS swap attestations, which allow them
+both to independently prove to third parties their membership.These
+attestations have a validity period so need to be periodically renewed.
+
+If a user leaves (or gets kicked out of) a group, either side can still use
+their attestation to "prove" their membership, until the attestation expires.
+Therefore attestations shouldn't be relied on to prove membership in important
+cases, but can for less important situtations, e.g. showing a users membership
+of groups on their profile, showing flairs, etc.abs
+
+An attestsation is a signed blob of json that looks like:
+
+    {
+        "user_id": "@foo:a.example.com",
+        "group_id": "+bar:b.example.com",
+        "valid_until_ms": 1507994728530,
+        "signatures":{"matrix.org":{"ed25519:auto":"..."}}
+    }
+"""
+
+import logging
+import random
+
 from twisted.internet import defer
 
 from synapse.api.errors import SynapseError
@@ -22,9 +47,17 @@ from synapse.util.logcontext import preserve_fn
 from signedjson.sign import sign_json
 
 
+logger = logging.getLogger(__name__)
+
+
 # Default validity duration for new attestations we create
 DEFAULT_ATTESTATION_LENGTH_MS = 3 * 24 * 60 * 60 * 1000
 
+# We add some jitter to the validity duration of attestations so that if we
+# add lots of users at once we don't need to renew them all at once.
+# The jitter is a multiplier picked randomly between the first and second number
+DEFAULT_ATTESTATION_JITTER = (0.9, 1.3)
+
 # Start trying to update our attestations when they come this close to expiring
 UPDATE_ATTESTATION_TIME_MS = 1 * 24 * 60 * 60 * 1000
 
@@ -73,10 +106,14 @@ class GroupAttestationSigning(object):
         """Create an attestation for the group_id and user_id with default
         validity length.
         """
+        validity_period = DEFAULT_ATTESTATION_LENGTH_MS
+        validity_period *= random.uniform(*DEFAULT_ATTESTATION_JITTER)
+        valid_until_ms = int(self.clock.time_msec() + validity_period)
+
         return sign_json({
             "group_id": group_id,
             "user_id": user_id,
-            "valid_until_ms": self.clock.time_msec() + DEFAULT_ATTESTATION_LENGTH_MS,
+            "valid_until_ms": valid_until_ms,
         }, self.server_name, self.signing_key)
 
 
@@ -128,12 +165,19 @@ class GroupAttestionRenewer(object):
 
         @defer.inlineCallbacks
         def _renew_attestation(group_id, user_id):
-            attestation = self.attestations.create_attestation(group_id, user_id)
-
-            if self.is_mine_id(group_id):
+            if not self.is_mine_id(group_id):
+                destination = get_domain_from_id(group_id)
+            elif not self.is_mine_id(user_id):
                 destination = get_domain_from_id(user_id)
             else:
-                destination = get_domain_from_id(group_id)
+                logger.warn(
+                    "Incorrectly trying to do attestations for user: %r in %r",
+                    user_id, group_id,
+                )
+                yield self.store.remove_attestation_renewal(group_id, user_id)
+                return
+
+            attestation = self.attestations.create_attestation(group_id, user_id)
 
             yield self.transport_client.renew_group_attestation(
                 destination, group_id, user_id,
diff --git a/synapse/groups/groups_server.py b/synapse/groups/groups_server.py
index 23beb3187e..11199dd215 100644
--- a/synapse/groups/groups_server.py
+++ b/synapse/groups/groups_server.py
@@ -49,7 +49,8 @@ class GroupsServerHandler(object):
         hs.get_groups_attestation_renewer()
 
     @defer.inlineCallbacks
-    def check_group_is_ours(self, group_id, and_exists=False, and_is_admin=None):
+    def check_group_is_ours(self, group_id, requester_user_id,
+                            and_exists=False, and_is_admin=None):
         """Check that the group is ours, and optionally if it exists.
 
         If group does exist then return group.
@@ -67,6 +68,10 @@ class GroupsServerHandler(object):
         if and_exists and not group:
             raise SynapseError(404, "Unknown group")
 
+        is_user_in_group = yield self.store.is_user_in_group(requester_user_id, group_id)
+        if group and not is_user_in_group and not group["is_public"]:
+            raise SynapseError(404, "Unknown group")
+
         if and_is_admin:
             is_admin = yield self.store.is_user_admin_in_group(group_id, and_is_admin)
             if not is_admin:
@@ -84,7 +89,7 @@ class GroupsServerHandler(object):
 
         A user/room may appear in multiple roles/categories.
         """
-        yield self.check_group_is_ours(group_id, and_exists=True)
+        yield self.check_group_is_ours(group_id, requester_user_id, and_exists=True)
 
         is_user_in_group = yield self.store.is_user_in_group(requester_user_id, group_id)
 
@@ -153,10 +158,16 @@ class GroupsServerHandler(object):
         })
 
     @defer.inlineCallbacks
-    def update_group_summary_room(self, group_id, user_id, room_id, category_id, content):
+    def update_group_summary_room(self, group_id, requester_user_id,
+                                  room_id, category_id, content):
         """Add/update a room to the group summary
         """
-        yield self.check_group_is_ours(group_id, and_exists=True, and_is_admin=user_id)
+        yield self.check_group_is_ours(
+            group_id,
+            requester_user_id,
+            and_exists=True,
+            and_is_admin=requester_user_id,
+        )
 
         RoomID.from_string(room_id)  # Ensure valid room id
 
@@ -175,10 +186,16 @@ class GroupsServerHandler(object):
         defer.returnValue({})
 
     @defer.inlineCallbacks
-    def delete_group_summary_room(self, group_id, user_id, room_id, category_id):
+    def delete_group_summary_room(self, group_id, requester_user_id,
+                                  room_id, category_id):
         """Remove a room from the summary
         """
-        yield self.check_group_is_ours(group_id, and_exists=True, and_is_admin=user_id)
+        yield self.check_group_is_ours(
+            group_id,
+            requester_user_id,
+            and_exists=True,
+            and_is_admin=requester_user_id,
+        )
 
         yield self.store.remove_room_from_summary(
             group_id=group_id,
@@ -189,10 +206,10 @@ class GroupsServerHandler(object):
         defer.returnValue({})
 
     @defer.inlineCallbacks
-    def get_group_categories(self, group_id, user_id):
+    def get_group_categories(self, group_id, requester_user_id):
         """Get all categories in a group (as seen by user)
         """
-        yield self.check_group_is_ours(group_id, and_exists=True)
+        yield self.check_group_is_ours(group_id, requester_user_id, and_exists=True)
 
         categories = yield self.store.get_group_categories(
             group_id=group_id,
@@ -200,10 +217,10 @@ class GroupsServerHandler(object):
         defer.returnValue({"categories": categories})
 
     @defer.inlineCallbacks
-    def get_group_category(self, group_id, user_id, category_id):
+    def get_group_category(self, group_id, requester_user_id, category_id):
         """Get a specific category in a group (as seen by user)
         """
-        yield self.check_group_is_ours(group_id, and_exists=True)
+        yield self.check_group_is_ours(group_id, requester_user_id, and_exists=True)
 
         res = yield self.store.get_group_category(
             group_id=group_id,
@@ -213,10 +230,15 @@ class GroupsServerHandler(object):
         defer.returnValue(res)
 
     @defer.inlineCallbacks
-    def update_group_category(self, group_id, user_id, category_id, content):
+    def update_group_category(self, group_id, requester_user_id, category_id, content):
         """Add/Update a group category
         """
-        yield self.check_group_is_ours(group_id, and_exists=True, and_is_admin=user_id)
+        yield self.check_group_is_ours(
+            group_id,
+            requester_user_id,
+            and_exists=True,
+            and_is_admin=requester_user_id,
+        )
 
         is_public = _parse_visibility_from_contents(content)
         profile = content.get("profile")
@@ -231,10 +253,15 @@ class GroupsServerHandler(object):
         defer.returnValue({})
 
     @defer.inlineCallbacks
-    def delete_group_category(self, group_id, user_id, category_id):
+    def delete_group_category(self, group_id, requester_user_id, category_id):
         """Delete a group category
         """
-        yield self.check_group_is_ours(group_id, and_exists=True, and_is_admin=user_id)
+        yield self.check_group_is_ours(
+            group_id,
+            requester_user_id,
+            and_exists=True,
+            and_is_admin=requester_user_id
+        )
 
         yield self.store.remove_group_category(
             group_id=group_id,
@@ -244,10 +271,10 @@ class GroupsServerHandler(object):
         defer.returnValue({})
 
     @defer.inlineCallbacks
-    def get_group_roles(self, group_id, user_id):
+    def get_group_roles(self, group_id, requester_user_id):
         """Get all roles in a group (as seen by user)
         """
-        yield self.check_group_is_ours(group_id, and_exists=True)
+        yield self.check_group_is_ours(group_id, requester_user_id, and_exists=True)
 
         roles = yield self.store.get_group_roles(
             group_id=group_id,
@@ -255,10 +282,10 @@ class GroupsServerHandler(object):
         defer.returnValue({"roles": roles})
 
     @defer.inlineCallbacks
-    def get_group_role(self, group_id, user_id, role_id):
+    def get_group_role(self, group_id, requester_user_id, role_id):
         """Get a specific role in a group (as seen by user)
         """
-        yield self.check_group_is_ours(group_id, and_exists=True)
+        yield self.check_group_is_ours(group_id, requester_user_id, and_exists=True)
 
         res = yield self.store.get_group_role(
             group_id=group_id,
@@ -267,10 +294,15 @@ class GroupsServerHandler(object):
         defer.returnValue(res)
 
     @defer.inlineCallbacks
-    def update_group_role(self, group_id, user_id, role_id, content):
+    def update_group_role(self, group_id, requester_user_id, role_id, content):
         """Add/update a role in a group
         """
-        yield self.check_group_is_ours(group_id, and_exists=True, and_is_admin=user_id)
+        yield self.check_group_is_ours(
+            group_id,
+            requester_user_id,
+            and_exists=True,
+            and_is_admin=requester_user_id,
+        )
 
         is_public = _parse_visibility_from_contents(content)
 
@@ -286,10 +318,15 @@ class GroupsServerHandler(object):
         defer.returnValue({})
 
     @defer.inlineCallbacks
-    def delete_group_role(self, group_id, user_id, role_id):
+    def delete_group_role(self, group_id, requester_user_id, role_id):
         """Remove role from group
         """
-        yield self.check_group_is_ours(group_id, and_exists=True, and_is_admin=user_id)
+        yield self.check_group_is_ours(
+            group_id,
+            requester_user_id,
+            and_exists=True,
+            and_is_admin=requester_user_id,
+        )
 
         yield self.store.remove_group_role(
             group_id=group_id,
@@ -304,7 +341,7 @@ class GroupsServerHandler(object):
         """Add/update a users entry in the group summary
         """
         yield self.check_group_is_ours(
-            group_id, and_exists=True, and_is_admin=requester_user_id,
+            group_id, requester_user_id, and_exists=True, and_is_admin=requester_user_id,
         )
 
         order = content.get("order", None)
@@ -326,7 +363,7 @@ class GroupsServerHandler(object):
         """Remove a user from the group summary
         """
         yield self.check_group_is_ours(
-            group_id, and_exists=True, and_is_admin=requester_user_id,
+            group_id, requester_user_id, and_exists=True, and_is_admin=requester_user_id,
         )
 
         yield self.store.remove_user_from_summary(
@@ -342,7 +379,7 @@ class GroupsServerHandler(object):
         """Get the group profile as seen by requester_user_id
         """
 
-        yield self.check_group_is_ours(group_id)
+        yield self.check_group_is_ours(group_id, requester_user_id)
 
         group_description = yield self.store.get_group(group_id)
 
@@ -356,7 +393,7 @@ class GroupsServerHandler(object):
         """Update the group profile
         """
         yield self.check_group_is_ours(
-            group_id, and_exists=True, and_is_admin=requester_user_id,
+            group_id, requester_user_id, and_exists=True, and_is_admin=requester_user_id,
         )
 
         profile = {}
@@ -377,7 +414,7 @@ class GroupsServerHandler(object):
         The ordering is arbitrary at the moment
         """
 
-        yield self.check_group_is_ours(group_id, and_exists=True)
+        yield self.check_group_is_ours(group_id, requester_user_id, and_exists=True)
 
         is_user_in_group = yield self.store.is_user_in_group(requester_user_id, group_id)
 
@@ -389,14 +426,15 @@ class GroupsServerHandler(object):
         for user_result in user_results:
             g_user_id = user_result["user_id"]
             is_public = user_result["is_public"]
+            is_privileged = user_result["is_admin"]
 
             entry = {"user_id": g_user_id}
 
             profile = yield self.profile_handler.get_profile_from_cache(g_user_id)
             entry.update(profile)
 
-            if not is_public:
-                entry["is_public"] = False
+            entry["is_public"] = bool(is_public)
+            entry["is_privileged"] = bool(is_privileged)
 
             if not self.is_mine_id(g_user_id):
                 attestation = yield self.store.get_remote_attestation(group_id, g_user_id)
@@ -425,7 +463,7 @@ class GroupsServerHandler(object):
         The ordering is arbitrary at the moment
         """
 
-        yield self.check_group_is_ours(group_id, and_exists=True)
+        yield self.check_group_is_ours(group_id, requester_user_id, and_exists=True)
 
         is_user_in_group = yield self.store.is_user_in_group(requester_user_id, group_id)
 
@@ -459,7 +497,7 @@ class GroupsServerHandler(object):
         This returns rooms in order of decreasing number of joined users
         """
 
-        yield self.check_group_is_ours(group_id, and_exists=True)
+        yield self.check_group_is_ours(group_id, requester_user_id, and_exists=True)
 
         is_user_in_group = yield self.store.is_user_in_group(requester_user_id, group_id)
 
@@ -470,7 +508,6 @@ class GroupsServerHandler(object):
         chunk = []
         for room_result in room_results:
             room_id = room_result["room_id"]
-            is_public = room_result["is_public"]
 
             joined_users = yield self.store.get_users_in_room(room_id)
             entry = yield self.room_list_handler.generate_room_entry(
@@ -481,8 +518,7 @@ class GroupsServerHandler(object):
             if not entry:
                 continue
 
-            if not is_public:
-                entry["is_public"] = False
+            entry["is_public"] = bool(room_result["is_public"])
 
             chunk.append(entry)
 
@@ -494,30 +530,33 @@ class GroupsServerHandler(object):
         })
 
     @defer.inlineCallbacks
-    def add_room_to_group(self, group_id, requester_user_id, room_id, content):
-        """Add room to group
+    def update_room_group_association(self, group_id, requester_user_id, room_id,
+                                      content):
+        """Add or update an association between room and group
         """
         RoomID.from_string(room_id)  # Ensure valid room id
 
         yield self.check_group_is_ours(
-            group_id, and_exists=True, and_is_admin=requester_user_id
+            group_id, requester_user_id, and_exists=True, and_is_admin=requester_user_id
         )
 
         is_public = _parse_visibility_from_contents(content)
 
-        yield self.store.add_room_to_group(group_id, room_id, is_public=is_public)
+        yield self.store.update_room_group_association(
+            group_id, room_id, is_public=is_public
+        )
 
         defer.returnValue({})
 
     @defer.inlineCallbacks
-    def remove_room_from_group(self, group_id, requester_user_id, room_id):
+    def delete_room_group_association(self, group_id, requester_user_id, room_id):
         """Remove room from group
         """
         yield self.check_group_is_ours(
-            group_id, and_exists=True, and_is_admin=requester_user_id
+            group_id, requester_user_id, and_exists=True, and_is_admin=requester_user_id
         )
 
-        yield self.store.remove_room_from_group(group_id, room_id)
+        yield self.store.delete_room_group_association(group_id, room_id)
 
         defer.returnValue({})
 
@@ -527,7 +566,7 @@ class GroupsServerHandler(object):
         """
 
         group = yield self.check_group_is_ours(
-            group_id, and_exists=True, and_is_admin=requester_user_id
+            group_id, requester_user_id, and_exists=True, and_is_admin=requester_user_id
         )
 
         # TODO: Check if user knocked
@@ -596,35 +635,40 @@ class GroupsServerHandler(object):
             raise SynapseError(502, "Unknown state returned by HS")
 
     @defer.inlineCallbacks
-    def accept_invite(self, group_id, user_id, content):
+    def accept_invite(self, group_id, requester_user_id, content):
         """User tries to accept an invite to the group.
 
         This is different from them asking to join, and so should error if no
         invite exists (and they're not a member of the group)
         """
 
-        yield self.check_group_is_ours(group_id, and_exists=True)
+        yield self.check_group_is_ours(group_id, requester_user_id, and_exists=True)
 
-        if not self.store.is_user_invited_to_local_group(group_id, user_id):
+        is_invited = yield self.store.is_user_invited_to_local_group(
+            group_id, requester_user_id,
+        )
+        if not is_invited:
             raise SynapseError(403, "User not invited to group")
 
-        if not self.hs.is_mine_id(user_id):
+        if not self.hs.is_mine_id(requester_user_id):
+            local_attestation = self.attestations.create_attestation(
+                group_id, requester_user_id,
+            )
             remote_attestation = content["attestation"]
 
             yield self.attestations.verify_attestation(
                 remote_attestation,
-                user_id=user_id,
+                user_id=requester_user_id,
                 group_id=group_id,
             )
         else:
+            local_attestation = None
             remote_attestation = None
 
-        local_attestation = self.attestations.create_attestation(group_id, user_id)
-
         is_public = _parse_visibility_from_contents(content)
 
         yield self.store.add_user_to_group(
-            group_id, user_id,
+            group_id, requester_user_id,
             is_admin=False,
             is_public=is_public,
             local_attestation=local_attestation,
@@ -637,31 +681,31 @@ class GroupsServerHandler(object):
         })
 
     @defer.inlineCallbacks
-    def knock(self, group_id, user_id, content):
+    def knock(self, group_id, requester_user_id, content):
         """A user requests becoming a member of the group
         """
-        yield self.check_group_is_ours(group_id, and_exists=True)
+        yield self.check_group_is_ours(group_id, requester_user_id, and_exists=True)
 
         raise NotImplementedError()
 
     @defer.inlineCallbacks
-    def accept_knock(self, group_id, user_id, content):
+    def accept_knock(self, group_id, requester_user_id, content):
         """Accept a users knock to the room.
 
         Errors if the user hasn't knocked, rather than inviting them.
         """
 
-        yield self.check_group_is_ours(group_id, and_exists=True)
+        yield self.check_group_is_ours(group_id, requester_user_id, and_exists=True)
 
         raise NotImplementedError()
 
     @defer.inlineCallbacks
     def remove_user_from_group(self, group_id, user_id, requester_user_id, content):
-        """Remove a user from the group; either a user is leaving or and admin
-        kicked htem.
+        """Remove a user from the group; either a user is leaving or an admin
+        kicked them.
         """
 
-        yield self.check_group_is_ours(group_id, and_exists=True)
+        yield self.check_group_is_ours(group_id, requester_user_id, and_exists=True)
 
         is_kick = False
         if requester_user_id != user_id:
@@ -692,8 +736,8 @@ class GroupsServerHandler(object):
         defer.returnValue({})
 
     @defer.inlineCallbacks
-    def create_group(self, group_id, user_id, content):
-        group = yield self.check_group_is_ours(group_id)
+    def create_group(self, group_id, requester_user_id, content):
+        group = yield self.check_group_is_ours(group_id, requester_user_id)
 
         logger.info("Attempting to create group with ID: %r", group_id)
 
@@ -703,11 +747,11 @@ class GroupsServerHandler(object):
         if group:
             raise SynapseError(400, "Group already exists")
 
-        is_admin = yield self.auth.is_server_admin(UserID.from_string(user_id))
+        is_admin = yield self.auth.is_server_admin(UserID.from_string(requester_user_id))
         if not is_admin:
             if not self.hs.config.enable_group_creation:
                 raise SynapseError(
-                    403, "Only server admin can create group on this server",
+                    403, "Only a server admin can create groups on this server",
                 )
             localpart = group_id_obj.localpart
             if not localpart.startswith(self.hs.config.group_creation_prefix):
@@ -727,38 +771,41 @@ class GroupsServerHandler(object):
 
         yield self.store.create_group(
             group_id,
-            user_id,
+            requester_user_id,
             name=name,
             avatar_url=avatar_url,
             short_description=short_description,
             long_description=long_description,
         )
 
-        if not self.hs.is_mine_id(user_id):
+        if not self.hs.is_mine_id(requester_user_id):
             remote_attestation = content["attestation"]
 
             yield self.attestations.verify_attestation(
                 remote_attestation,
-                user_id=user_id,
+                user_id=requester_user_id,
                 group_id=group_id,
             )
 
-            local_attestation = self.attestations.create_attestation(group_id, user_id)
+            local_attestation = self.attestations.create_attestation(
+                group_id,
+                requester_user_id,
+            )
         else:
             local_attestation = None
             remote_attestation = None
 
         yield self.store.add_user_to_group(
-            group_id, user_id,
+            group_id, requester_user_id,
             is_admin=True,
             is_public=True,  # TODO
             local_attestation=local_attestation,
             remote_attestation=remote_attestation,
         )
 
-        if not self.hs.is_mine_id(user_id):
+        if not self.hs.is_mine_id(requester_user_id):
             yield self.store.add_remote_profile_cache(
-                user_id,
+                requester_user_id,
                 displayname=user_profile.get("displayname"),
                 avatar_url=user_profile.get("avatar_url"),
             )
diff --git a/synapse/handlers/auth.py b/synapse/handlers/auth.py
index 9cef9d184b..7a0ba6ef35 100644
--- a/synapse/handlers/auth.py
+++ b/synapse/handlers/auth.py
@@ -13,13 +13,13 @@
 # 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
 
 from ._base import BaseHandler
 from synapse.api.constants import LoginType
-from synapse.types import UserID
 from synapse.api.errors import AuthError, LoginError, Codes, StoreError, SynapseError
+from synapse.module_api import ModuleApi
+from synapse.types import UserID
 from synapse.util.async import run_on_reactor
 from synapse.util.caches.expiringcache import ExpiringCache
 
@@ -63,10 +63,7 @@ class AuthHandler(BaseHandler):
             reset_expiry_on_get=True,
         )
 
-        account_handler = _AccountHandler(
-            hs, check_user_exists=self.check_user_exists
-        )
-
+        account_handler = ModuleApi(hs, self)
         self.password_providers = [
             module(config=config, account_handler=account_handler)
             for module, config in hs.config.password_providers
@@ -75,14 +72,24 @@ class AuthHandler(BaseHandler):
         logger.info("Extra password_providers: %r", self.password_providers)
 
         self.hs = hs  # FIXME better possibility to access registrationHandler later?
-        self.device_handler = hs.get_device_handler()
         self.macaroon_gen = hs.get_macaroon_generator()
+        self._password_enabled = hs.config.password_enabled
+
+        login_types = set()
+        if self._password_enabled:
+            login_types.add(LoginType.PASSWORD)
+        for provider in self.password_providers:
+            if hasattr(provider, "get_supported_login_types"):
+                login_types.update(
+                    provider.get_supported_login_types().keys()
+                )
+        self._supported_login_types = frozenset(login_types)
 
     @defer.inlineCallbacks
     def check_auth(self, flows, clientdict, clientip):
         """
         Takes a dictionary sent by the client in the login / registration
-        protocol and handles the login flow.
+        protocol and handles the User-Interactive Auth flow.
 
         As a side effect, this function fills in the 'creds' key on the user's
         session with a map, which maps each auth-type (str) to the relevant
@@ -260,16 +267,19 @@ class AuthHandler(BaseHandler):
         sess = self._get_session_info(session_id)
         return sess.setdefault('serverdict', {}).get(key, default)
 
+    @defer.inlineCallbacks
     def _check_password_auth(self, authdict, _):
         if "user" not in authdict or "password" not in authdict:
             raise LoginError(400, "", Codes.MISSING_PARAM)
 
         user_id = authdict["user"]
         password = authdict["password"]
-        if not user_id.startswith('@'):
-            user_id = UserID(user_id, self.hs.hostname).to_string()
 
-        return self._check_password(user_id, password)
+        (canonical_id, callback) = yield self.validate_login(user_id, {
+            "type": LoginType.PASSWORD,
+            "password": password,
+        })
+        defer.returnValue(canonical_id)
 
     @defer.inlineCallbacks
     def _check_recaptcha(self, authdict, clientip):
@@ -398,26 +408,8 @@ class AuthHandler(BaseHandler):
 
         return self.sessions[session_id]
 
-    def validate_password_login(self, user_id, password):
-        """
-        Authenticates the user with their username and password.
-
-        Used only by the v1 login API.
-
-        Args:
-            user_id (str): complete @user:id
-            password (str): Password
-        Returns:
-            defer.Deferred: (str) canonical user id
-        Raises:
-            StoreError if there was a problem accessing the database
-            LoginError if there was an authentication problem.
-        """
-        return self._check_password(user_id, password)
-
     @defer.inlineCallbacks
-    def get_access_token_for_user_id(self, user_id, device_id=None,
-                                     initial_display_name=None):
+    def get_access_token_for_user_id(self, user_id, device_id=None):
         """
         Creates a new access token for the user with the given user ID.
 
@@ -431,13 +423,10 @@ class AuthHandler(BaseHandler):
             device_id (str|None): the device ID to associate with the tokens.
                None to leave the tokens unassociated with a device (deprecated:
                we should always have a device ID)
-            initial_display_name (str): display name to associate with the
-               device if it needs re-registering
         Returns:
               The access token for the user's session.
         Raises:
             StoreError if there was a problem storing the token.
-            LoginError if there was an authentication problem.
         """
         logger.info("Logging in user %s on device %s", user_id, device_id)
         access_token = yield self.issue_access_token(user_id, device_id)
@@ -447,9 +436,11 @@ class AuthHandler(BaseHandler):
         # really don't want is active access_tokens without a record of the
         # device, so we double-check it here.
         if device_id is not None:
-            yield self.device_handler.check_device_registered(
-                user_id, device_id, initial_display_name
-            )
+            try:
+                yield self.store.get_device(user_id, device_id)
+            except StoreError:
+                yield self.store.delete_access_token(access_token)
+                raise StoreError(400, "Login raced against device deletion")
 
         defer.returnValue(access_token)
 
@@ -501,29 +492,115 @@ class AuthHandler(BaseHandler):
             )
         defer.returnValue(result)
 
+    def get_supported_login_types(self):
+        """Get a the login types supported for the /login API
+
+        By default this is just 'm.login.password' (unless password_enabled is
+        False in the config file), but password auth providers can provide
+        other login types.
+
+        Returns:
+            Iterable[str]: login types
+        """
+        return self._supported_login_types
+
     @defer.inlineCallbacks
-    def _check_password(self, user_id, password):
-        """Authenticate a user against the LDAP and local databases.
+    def validate_login(self, username, login_submission):
+        """Authenticates the user for the /login API
 
-        user_id is checked case insensitively against the local database, but
-        will throw if there are multiple inexact matches.
+        Also used by the user-interactive auth flow to validate
+        m.login.password auth types.
 
         Args:
-            user_id (str): complete @user:id
+            username (str): username supplied by the user
+            login_submission (dict): the whole of the login submission
+                (including 'type' and other relevant fields)
         Returns:
-            (str) the canonical_user_id
+            Deferred[str, func]: canonical user id, and optional callback
+                to be called once the access token and device id are issued
         Raises:
-            LoginError if login fails
+            StoreError if there was a problem accessing the database
+            SynapseError if there was a problem with the request
+            LoginError if there was an authentication problem.
         """
+
+        if username.startswith('@'):
+            qualified_user_id = username
+        else:
+            qualified_user_id = UserID(
+                username, self.hs.hostname
+            ).to_string()
+
+        login_type = login_submission.get("type")
+        known_login_type = False
+
+        # special case to check for "password" for the check_password interface
+        # for the auth providers
+        password = login_submission.get("password")
+        if login_type == LoginType.PASSWORD:
+            if not self._password_enabled:
+                raise SynapseError(400, "Password login has been disabled.")
+            if not password:
+                raise SynapseError(400, "Missing parameter: password")
+
         for provider in self.password_providers:
-            is_valid = yield provider.check_password(user_id, password)
-            if is_valid:
-                defer.returnValue(user_id)
+            if (hasattr(provider, "check_password")
+                    and login_type == LoginType.PASSWORD):
+                known_login_type = True
+                is_valid = yield provider.check_password(
+                    qualified_user_id, password,
+                )
+                if is_valid:
+                    defer.returnValue(qualified_user_id)
+
+            if (not hasattr(provider, "get_supported_login_types")
+                    or not hasattr(provider, "check_auth")):
+                # this password provider doesn't understand custom login types
+                continue
+
+            supported_login_types = provider.get_supported_login_types()
+            if login_type not in supported_login_types:
+                # this password provider doesn't understand this login type
+                continue
+
+            known_login_type = True
+            login_fields = supported_login_types[login_type]
+
+            missing_fields = []
+            login_dict = {}
+            for f in login_fields:
+                if f not in login_submission:
+                    missing_fields.append(f)
+                else:
+                    login_dict[f] = login_submission[f]
+            if missing_fields:
+                raise SynapseError(
+                    400, "Missing parameters for login type %s: %s" % (
+                        login_type,
+                        missing_fields,
+                    ),
+                )
+
+            result = yield provider.check_auth(
+                username, login_type, login_dict,
+            )
+            if result:
+                if isinstance(result, str):
+                    result = (result, None)
+                defer.returnValue(result)
+
+        if login_type == LoginType.PASSWORD:
+            known_login_type = True
+
+            canonical_user_id = yield self._check_local_password(
+                qualified_user_id, password,
+            )
 
-        canonical_user_id = yield self._check_local_password(user_id, password)
+            if canonical_user_id:
+                defer.returnValue((canonical_user_id, None))
 
-        if canonical_user_id:
-            defer.returnValue(canonical_user_id)
+        if not known_login_type:
+            raise SynapseError(400, "Unknown login type %s" % login_type)
 
         # unknown username or invalid password. We raise a 403 here, but note
         # that if we're doing user-interactive login, it turns all LoginErrors
@@ -584,14 +661,81 @@ class AuthHandler(BaseHandler):
             if e.code == 404:
                 raise SynapseError(404, "Unknown user", Codes.NOT_FOUND)
             raise e
-        yield self.store.user_delete_access_tokens(
-            user_id, except_access_token_id
+        yield self.delete_access_tokens_for_user(
+            user_id, except_token_id=except_access_token_id,
         )
         yield self.hs.get_pusherpool().remove_pushers_by_user(
             user_id, except_access_token_id
         )
 
     @defer.inlineCallbacks
+    def deactivate_account(self, user_id):
+        """Deactivate a user's account
+
+        Args:
+            user_id (str): ID of user to be deactivated
+
+        Returns:
+            Deferred
+        """
+        # FIXME: Theoretically there is a race here wherein user resets
+        # password using threepid.
+        yield self.delete_access_tokens_for_user(user_id)
+        yield self.store.user_delete_threepids(user_id)
+        yield self.store.user_set_password_hash(user_id, None)
+
+    @defer.inlineCallbacks
+    def delete_access_token(self, access_token):
+        """Invalidate a single access token
+
+        Args:
+            access_token (str): access token to be deleted
+
+        Returns:
+            Deferred
+        """
+        user_info = yield self.auth.get_user_by_access_token(access_token)
+        yield self.store.delete_access_token(access_token)
+
+        # see if any of our auth providers want to know about this
+        for provider in self.password_providers:
+            if hasattr(provider, "on_logged_out"):
+                yield provider.on_logged_out(
+                    user_id=str(user_info["user"]),
+                    device_id=user_info["device_id"],
+                    access_token=access_token,
+                )
+
+    @defer.inlineCallbacks
+    def delete_access_tokens_for_user(self, user_id, except_token_id=None,
+                                      device_id=None):
+        """Invalidate access tokens belonging to a user
+
+        Args:
+            user_id (str):  ID of user the tokens belong to
+            except_token_id (str|None): access_token ID which should *not* be
+                deleted
+            device_id (str|None):  ID of device the tokens are associated with.
+                If None, tokens associated with any device (or no device) will
+                be deleted
+        Returns:
+            Deferred
+        """
+        tokens_and_devices = yield self.store.user_delete_access_tokens(
+            user_id, except_token_id=except_token_id, device_id=device_id,
+        )
+
+        # see if any of our auth providers want to know about this
+        for provider in self.password_providers:
+            if hasattr(provider, "on_logged_out"):
+                for token, device_id in tokens_and_devices:
+                    yield provider.on_logged_out(
+                        user_id=user_id,
+                        device_id=device_id,
+                        access_token=token,
+                    )
+
+    @defer.inlineCallbacks
     def add_threepid(self, user_id, medium, address, validated_at):
         # 'Canonicalise' email addresses down to lower case.
         # We've now moving towards the Home Server being the entity that
@@ -696,30 +840,3 @@ class MacaroonGeneartor(object):
         macaroon.add_first_party_caveat("gen = 1")
         macaroon.add_first_party_caveat("user_id = %s" % (user_id,))
         return macaroon
-
-
-class _AccountHandler(object):
-    """A proxy object that gets passed to password auth providers so they
-    can register new users etc if necessary.
-    """
-    def __init__(self, hs, check_user_exists):
-        self.hs = hs
-
-        self._check_user_exists = check_user_exists
-
-    def check_user_exists(self, user_id):
-        """Check if user exissts.
-
-        Returns:
-            Deferred(bool)
-        """
-        return self._check_user_exists(user_id)
-
-    def register(self, localpart):
-        """Registers a new user with given localpart
-
-        Returns:
-            Deferred: a 2-tuple of (user_id, access_token)
-        """
-        reg = self.hs.get_handlers().registration_handler
-        return reg.register(localpart=localpart)
diff --git a/synapse/handlers/device.py b/synapse/handlers/device.py
index dac4b3f4e0..579d8477ba 100644
--- a/synapse/handlers/device.py
+++ b/synapse/handlers/device.py
@@ -34,6 +34,7 @@ class DeviceHandler(BaseHandler):
 
         self.hs = hs
         self.state = hs.get_state_handler()
+        self._auth_handler = hs.get_auth_handler()
         self.federation_sender = hs.get_federation_sender()
         self.federation = hs.get_replication_layer()
 
@@ -159,9 +160,8 @@ class DeviceHandler(BaseHandler):
             else:
                 raise
 
-        yield self.store.user_delete_access_tokens(
+        yield self._auth_handler.delete_access_tokens_for_user(
             user_id, device_id=device_id,
-            delete_refresh_tokens=True,
         )
 
         yield self.store.delete_e2e_keys_by_device(
@@ -194,9 +194,8 @@ class DeviceHandler(BaseHandler):
         # Delete access tokens and e2e keys for each device. Not optimised as it is not
         # considered as part of a critical path.
         for device_id in device_ids:
-            yield self.store.user_delete_access_tokens(
+            yield self._auth_handler.delete_access_tokens_for_user(
                 user_id, device_id=device_id,
-                delete_refresh_tokens=True,
             )
             yield self.store.delete_e2e_keys_by_device(
                 user_id=user_id, device_id=device_id
diff --git a/synapse/handlers/groups_local.py b/synapse/handlers/groups_local.py
index 6699d0888f..dabc2a3fbb 100644
--- a/synapse/handlers/groups_local.py
+++ b/synapse/handlers/groups_local.py
@@ -70,8 +70,8 @@ class GroupsLocalHandler(object):
 
     get_invited_users_in_group = _create_rerouter("get_invited_users_in_group")
 
-    add_room_to_group = _create_rerouter("add_room_to_group")
-    remove_room_from_group = _create_rerouter("remove_room_from_group")
+    update_room_group_association = _create_rerouter("update_room_group_association")
+    delete_room_group_association = _create_rerouter("delete_room_group_association")
 
     update_group_summary_room = _create_rerouter("update_group_summary_room")
     delete_group_summary_room = _create_rerouter("delete_group_summary_room")
diff --git a/synapse/handlers/register.py b/synapse/handlers/register.py
index 49dc33c147..f6e7e58563 100644
--- a/synapse/handlers/register.py
+++ b/synapse/handlers/register.py
@@ -36,6 +36,7 @@ class RegistrationHandler(BaseHandler):
         super(RegistrationHandler, self).__init__(hs)
 
         self.auth = hs.get_auth()
+        self._auth_handler = hs.get_auth_handler()
         self.profile_handler = hs.get_profile_handler()
         self.captcha_client = CaptchaServerHttpClient(hs)
 
@@ -416,7 +417,7 @@ class RegistrationHandler(BaseHandler):
                 create_profile_with_localpart=user.localpart,
             )
         else:
-            yield self.store.user_delete_access_tokens(user_id=user_id)
+            yield self._auth_handler.delete_access_tokens_for_user(user_id)
             yield self.store.add_access_token_to_user(user_id=user_id, token=token)
 
         if displayname is not None:
diff --git a/synapse/handlers/room_list.py b/synapse/handlers/room_list.py
index 41e1781df7..2cf34e51cb 100644
--- a/synapse/handlers/room_list.py
+++ b/synapse/handlers/room_list.py
@@ -20,6 +20,7 @@ from ._base import BaseHandler
 from synapse.api.constants import (
     EventTypes, JoinRules,
 )
+from synapse.util.logcontext import make_deferred_yieldable, preserve_fn
 from synapse.util.async import concurrently_execute
 from synapse.util.caches.descriptors import cachedInlineCallbacks
 from synapse.util.caches.response_cache import ResponseCache
@@ -70,6 +71,7 @@ class RoomListHandler(BaseHandler):
         if search_filter:
             # We explicitly don't bother caching searches or requests for
             # appservice specific lists.
+            logger.info("Bypassing cache as search request.")
             return self._get_public_room_list(
                 limit, since_token, search_filter, network_tuple=network_tuple,
             )
@@ -77,13 +79,16 @@ class RoomListHandler(BaseHandler):
         key = (limit, since_token, network_tuple)
         result = self.response_cache.get(key)
         if not result:
+            logger.info("No cached result, calculating one.")
             result = self.response_cache.set(
                 key,
-                self._get_public_room_list(
+                preserve_fn(self._get_public_room_list)(
                     limit, since_token, network_tuple=network_tuple
                 )
             )
-        return result
+        else:
+            logger.info("Using cached deferred result.")
+        return make_deferred_yieldable(result)
 
     @defer.inlineCallbacks
     def _get_public_room_list(self, limit=None, since_token=None,
diff --git a/synapse/handlers/sync.py b/synapse/handlers/sync.py
index 219529936f..b12988f3c9 100644
--- a/synapse/handlers/sync.py
+++ b/synapse/handlers/sync.py
@@ -15,7 +15,7 @@
 
 from synapse.api.constants import Membership, EventTypes
 from synapse.util.async import concurrently_execute
-from synapse.util.logcontext import LoggingContext
+from synapse.util.logcontext import LoggingContext, make_deferred_yieldable, preserve_fn
 from synapse.util.metrics import Measure, measure_func
 from synapse.util.caches.response_cache import ResponseCache
 from synapse.push.clientformat import format_push_rules_for_user
@@ -184,11 +184,11 @@ class SyncHandler(object):
         if not result:
             result = self.response_cache.set(
                 sync_config.request_key,
-                self._wait_for_sync_for_user(
+                preserve_fn(self._wait_for_sync_for_user)(
                     sync_config, since_token, timeout, full_state
                 )
             )
-        return result
+        return make_deferred_yieldable(result)
 
     @defer.inlineCallbacks
     def _wait_for_sync_for_user(self, sync_config, since_token, timeout,
diff --git a/synapse/http/additional_resource.py b/synapse/http/additional_resource.py
new file mode 100644
index 0000000000..343e932cb1
--- /dev/null
+++ b/synapse/http/additional_resource.py
@@ -0,0 +1,55 @@
+# -*- coding: utf-8 -*-
+# Copyright 2017 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.
+
+from synapse.http.server import wrap_request_handler
+from twisted.web.resource import Resource
+from twisted.web.server import NOT_DONE_YET
+
+
+class AdditionalResource(Resource):
+    """Resource wrapper for additional_resources
+
+    If the user has configured additional_resources, we need to wrap the
+    handler class with a Resource so that we can map it into the resource tree.
+
+    This class is also where we wrap the request handler with logging, metrics,
+    and exception handling.
+    """
+    def __init__(self, hs, handler):
+        """Initialise AdditionalResource
+
+        The ``handler`` should return a deferred which completes when it has
+        done handling the request. It should write a response with
+        ``request.write()``, and call ``request.finish()``.
+
+        Args:
+            hs (synapse.server.HomeServer): homeserver
+            handler ((twisted.web.server.Request) -> twisted.internet.defer.Deferred):
+                function to be called to handle the request.
+        """
+        Resource.__init__(self)
+        self._handler = handler
+
+        # these are required by the request_handler wrapper
+        self.version_string = hs.version_string
+        self.clock = hs.get_clock()
+
+    def render(self, request):
+        self._async_render(request)
+        return NOT_DONE_YET
+
+    @wrap_request_handler
+    def _async_render(self, request):
+        return self._handler(request)
diff --git a/synapse/http/client.py b/synapse/http/client.py
index 9eba046bbf..4abb479ae3 100644
--- a/synapse/http/client.py
+++ b/synapse/http/client.py
@@ -18,7 +18,7 @@ from OpenSSL.SSL import VERIFY_NONE
 from synapse.api.errors import (
     CodeMessageException, MatrixCodeMessageException, SynapseError, Codes,
 )
-from synapse.util.logcontext import preserve_context_over_fn
+from synapse.util.logcontext import make_deferred_yieldable
 from synapse.util import logcontext
 import synapse.metrics
 from synapse.http.endpoint import SpiderEndpoint
@@ -114,43 +114,73 @@ class SimpleHttpClient(object):
             raise e
 
     @defer.inlineCallbacks
-    def post_urlencoded_get_json(self, uri, args={}):
+    def post_urlencoded_get_json(self, uri, args={}, headers=None):
+        """
+        Args:
+            uri (str):
+            args (dict[str, str|List[str]]): query params
+            headers (dict[str, List[str]]|None): If not None, a map from
+               header name to a list of values for that header
+
+        Returns:
+            Deferred[object]: parsed json
+        """
+
         # TODO: Do we ever want to log message contents?
         logger.debug("post_urlencoded_get_json args: %s", args)
 
         query_bytes = urllib.urlencode(encode_urlencode_args(args), True)
 
+        actual_headers = {
+            b"Content-Type": [b"application/x-www-form-urlencoded"],
+            b"User-Agent": [self.user_agent],
+        }
+        if headers:
+            actual_headers.update(headers)
+
         response = yield self.request(
             "POST",
             uri.encode("ascii"),
-            headers=Headers({
-                b"Content-Type": [b"application/x-www-form-urlencoded"],
-                b"User-Agent": [self.user_agent],
-            }),
+            headers=Headers(actual_headers),
             bodyProducer=FileBodyProducer(StringIO(query_bytes))
         )
 
-        body = yield preserve_context_over_fn(readBody, response)
+        body = yield make_deferred_yieldable(readBody(response))
 
         defer.returnValue(json.loads(body))
 
     @defer.inlineCallbacks
-    def post_json_get_json(self, uri, post_json):
+    def post_json_get_json(self, uri, post_json, headers=None):
+        """
+
+        Args:
+            uri (str):
+            post_json (object):
+            headers (dict[str, List[str]]|None): If not None, a map from
+               header name to a list of values for that header
+
+        Returns:
+            Deferred[object]: parsed json
+        """
         json_str = encode_canonical_json(post_json)
 
         logger.debug("HTTP POST %s -> %s", json_str, uri)
 
+        actual_headers = {
+            b"Content-Type": [b"application/json"],
+            b"User-Agent": [self.user_agent],
+        }
+        if headers:
+            actual_headers.update(headers)
+
         response = yield self.request(
             "POST",
             uri.encode("ascii"),
-            headers=Headers({
-                b"Content-Type": [b"application/json"],
-                b"User-Agent": [self.user_agent],
-            }),
+            headers=Headers(actual_headers),
             bodyProducer=FileBodyProducer(StringIO(json_str))
         )
 
-        body = yield preserve_context_over_fn(readBody, response)
+        body = yield make_deferred_yieldable(readBody(response))
 
         if 200 <= response.code < 300:
             defer.returnValue(json.loads(body))
@@ -160,7 +190,7 @@ class SimpleHttpClient(object):
         defer.returnValue(json.loads(body))
 
     @defer.inlineCallbacks
-    def get_json(self, uri, args={}):
+    def get_json(self, uri, args={}, headers=None):
         """ Gets some json from the given URI.
 
         Args:
@@ -169,6 +199,8 @@ class SimpleHttpClient(object):
                 None.
                 **Note**: The value of each key is assumed to be an iterable
                 and *not* a string.
+            headers (dict[str, List[str]]|None): If not None, a map from
+               header name to a list of values for that header
         Returns:
             Deferred: Succeeds when we get *any* 2xx HTTP response, with the
             HTTP body as JSON.
@@ -177,13 +209,13 @@ class SimpleHttpClient(object):
             error message.
         """
         try:
-            body = yield self.get_raw(uri, args)
+            body = yield self.get_raw(uri, args, headers=headers)
             defer.returnValue(json.loads(body))
         except CodeMessageException as e:
             raise self._exceptionFromFailedRequest(e.code, e.msg)
 
     @defer.inlineCallbacks
-    def put_json(self, uri, json_body, args={}):
+    def put_json(self, uri, json_body, args={}, headers=None):
         """ Puts some json to the given URI.
 
         Args:
@@ -193,6 +225,8 @@ class SimpleHttpClient(object):
                 None.
                 **Note**: The value of each key is assumed to be an iterable
                 and *not* a string.
+            headers (dict[str, List[str]]|None): If not None, a map from
+               header name to a list of values for that header
         Returns:
             Deferred: Succeeds when we get *any* 2xx HTTP response, with the
             HTTP body as JSON.
@@ -205,17 +239,21 @@ class SimpleHttpClient(object):
 
         json_str = encode_canonical_json(json_body)
 
+        actual_headers = {
+            b"Content-Type": [b"application/json"],
+            b"User-Agent": [self.user_agent],
+        }
+        if headers:
+            actual_headers.update(headers)
+
         response = yield self.request(
             "PUT",
             uri.encode("ascii"),
-            headers=Headers({
-                b"User-Agent": [self.user_agent],
-                "Content-Type": ["application/json"]
-            }),
+            headers=Headers(actual_headers),
             bodyProducer=FileBodyProducer(StringIO(json_str))
         )
 
-        body = yield preserve_context_over_fn(readBody, response)
+        body = yield make_deferred_yieldable(readBody(response))
 
         if 200 <= response.code < 300:
             defer.returnValue(json.loads(body))
@@ -226,7 +264,7 @@ class SimpleHttpClient(object):
             raise CodeMessageException(response.code, body)
 
     @defer.inlineCallbacks
-    def get_raw(self, uri, args={}):
+    def get_raw(self, uri, args={}, headers=None):
         """ Gets raw text from the given URI.
 
         Args:
@@ -235,6 +273,8 @@ class SimpleHttpClient(object):
                 None.
                 **Note**: The value of each key is assumed to be an iterable
                 and *not* a string.
+            headers (dict[str, List[str]]|None): If not None, a map from
+               header name to a list of values for that header
         Returns:
             Deferred: Succeeds when we get *any* 2xx HTTP response, with the
             HTTP body at text.
@@ -246,15 +286,19 @@ class SimpleHttpClient(object):
             query_bytes = urllib.urlencode(args, True)
             uri = "%s?%s" % (uri, query_bytes)
 
+        actual_headers = {
+            b"User-Agent": [self.user_agent],
+        }
+        if headers:
+            actual_headers.update(headers)
+
         response = yield self.request(
             "GET",
             uri.encode("ascii"),
-            headers=Headers({
-                b"User-Agent": [self.user_agent],
-            })
+            headers=Headers(actual_headers),
         )
 
-        body = yield preserve_context_over_fn(readBody, response)
+        body = yield make_deferred_yieldable(readBody(response))
 
         if 200 <= response.code < 300:
             defer.returnValue(body)
@@ -274,27 +318,33 @@ class SimpleHttpClient(object):
     # The two should be factored out.
 
     @defer.inlineCallbacks
-    def get_file(self, url, output_stream, max_size=None):
+    def get_file(self, url, output_stream, max_size=None, headers=None):
         """GETs a file from a given URL
         Args:
             url (str): The URL to GET
             output_stream (file): File to write the response body to.
+            headers (dict[str, List[str]]|None): If not None, a map from
+               header name to a list of values for that header
         Returns:
             A (int,dict,string,int) tuple of the file length, dict of the response
             headers, absolute URI of the response and HTTP response code.
         """
 
+        actual_headers = {
+            b"User-Agent": [self.user_agent],
+        }
+        if headers:
+            actual_headers.update(headers)
+
         response = yield self.request(
             "GET",
             url.encode("ascii"),
-            headers=Headers({
-                b"User-Agent": [self.user_agent],
-            })
+            headers=Headers(actual_headers),
         )
 
-        headers = dict(response.headers.getAllRawHeaders())
+        resp_headers = dict(response.headers.getAllRawHeaders())
 
-        if 'Content-Length' in headers and headers['Content-Length'] > max_size:
+        if 'Content-Length' in resp_headers and resp_headers['Content-Length'] > max_size:
             logger.warn("Requested URL is too large > %r bytes" % (self.max_size,))
             raise SynapseError(
                 502,
@@ -315,10 +365,9 @@ class SimpleHttpClient(object):
         # straight back in again
 
         try:
-            length = yield preserve_context_over_fn(
-                _readBodyToFile,
-                response, output_stream, max_size
-            )
+            length = yield make_deferred_yieldable(_readBodyToFile(
+                response, output_stream, max_size,
+            ))
         except Exception as e:
             logger.exception("Failed to download body")
             raise SynapseError(
@@ -327,7 +376,9 @@ class SimpleHttpClient(object):
                 Codes.UNKNOWN,
             )
 
-        defer.returnValue((length, headers, response.request.absoluteURI, response.code))
+        defer.returnValue(
+            (length, resp_headers, response.request.absoluteURI, response.code),
+        )
 
 
 # XXX: FIXME: This is horribly copy-pasted from matrixfederationclient.
@@ -395,7 +446,7 @@ class CaptchaServerHttpClient(SimpleHttpClient):
         )
 
         try:
-            body = yield preserve_context_over_fn(readBody, response)
+            body = yield make_deferred_yieldable(readBody(response))
             defer.returnValue(body)
         except PartialDownloadError as e:
             # twisted dislikes google's response, no content length.
diff --git a/synapse/module_api/__init__.py b/synapse/module_api/__init__.py
new file mode 100644
index 0000000000..dc680ddf43
--- /dev/null
+++ b/synapse/module_api/__init__.py
@@ -0,0 +1,113 @@
+# -*- coding: utf-8 -*-
+# Copyright 2017 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.
+
+from synapse.types import UserID
+
+
+class ModuleApi(object):
+    """A proxy object that gets passed to password auth providers so they
+    can register new users etc if necessary.
+    """
+    def __init__(self, hs, auth_handler):
+        self.hs = hs
+
+        self._store = hs.get_datastore()
+        self._auth = hs.get_auth()
+        self._auth_handler = auth_handler
+
+    def get_user_by_req(self, req, allow_guest=False):
+        """Check the access_token provided for a request
+
+        Args:
+            req (twisted.web.server.Request): Incoming HTTP request
+            allow_guest (bool): True if guest users should be allowed. If this
+                is False, and the access token is for a guest user, an
+                AuthError will be thrown
+        Returns:
+            twisted.internet.defer.Deferred[synapse.types.Requester]:
+                the requester for this request
+        Raises:
+            synapse.api.errors.AuthError: if no user by that token exists,
+                or the token is invalid.
+        """
+        return self._auth.get_user_by_req(req, allow_guest)
+
+    def get_qualified_user_id(self, username):
+        """Qualify a user id, if necessary
+
+        Takes a user id provided by the user and adds the @ and :domain to
+        qualify it, if necessary
+
+        Args:
+            username (str): provided user id
+
+        Returns:
+            str: qualified @user:id
+        """
+        if username.startswith('@'):
+            return username
+        return UserID(username, self.hs.hostname).to_string()
+
+    def check_user_exists(self, user_id):
+        """Check if user exists.
+
+        Args:
+            user_id (str): Complete @user:id
+
+        Returns:
+            Deferred[str|None]: Canonical (case-corrected) user_id, or None
+               if the user is not registered.
+        """
+        return self._auth_handler.check_user_exists(user_id)
+
+    def register(self, localpart):
+        """Registers a new user with given localpart
+
+        Returns:
+            Deferred: a 2-tuple of (user_id, access_token)
+        """
+        reg = self.hs.get_handlers().registration_handler
+        return reg.register(localpart=localpart)
+
+    def invalidate_access_token(self, access_token):
+        """Invalidate an access token for a user
+
+        Args:
+            access_token(str): access token
+
+        Returns:
+            twisted.internet.defer.Deferred - resolves once the access token
+               has been removed.
+
+        Raises:
+            synapse.api.errors.AuthError: the access token is invalid
+        """
+
+        return self._auth_handler.delete_access_token(access_token)
+
+    def run_db_interaction(self, desc, func, *args, **kwargs):
+        """Run a function with a database connection
+
+        Args:
+            desc (str): description for the transaction, for metrics etc
+            func (func): function to be run. Passed a database cursor object
+                as well as *args and **kwargs
+            *args: positional args to be passed to func
+            **kwargs: named args to be passed to func
+
+        Returns:
+            Deferred[object]: result of func
+        """
+        return self._store.runInteraction(desc, func, *args, **kwargs)
diff --git a/synapse/rest/client/v1/admin.py b/synapse/rest/client/v1/admin.py
index 465b25033d..1197158fdc 100644
--- a/synapse/rest/client/v1/admin.py
+++ b/synapse/rest/client/v1/admin.py
@@ -137,7 +137,7 @@ class DeactivateAccountRestServlet(ClientV1RestServlet):
     PATTERNS = client_path_patterns("/admin/deactivate/(?P<target_user_id>[^/]*)")
 
     def __init__(self, hs):
-        self.store = hs.get_datastore()
+        self._auth_handler = hs.get_auth_handler()
         super(DeactivateAccountRestServlet, self).__init__(hs)
 
     @defer.inlineCallbacks
@@ -149,12 +149,7 @@ class DeactivateAccountRestServlet(ClientV1RestServlet):
         if not is_admin:
             raise AuthError(403, "You are not a server admin")
 
-        # FIXME: Theoretically there is a race here wherein user resets password
-        # using threepid.
-        yield self.store.user_delete_access_tokens(target_user_id)
-        yield self.store.user_delete_threepids(target_user_id)
-        yield self.store.user_set_password_hash(target_user_id, None)
-
+        yield self._auth_handler.deactivate_account(target_user_id)
         defer.returnValue((200, {}))
 
 
diff --git a/synapse/rest/client/v1/login.py b/synapse/rest/client/v1/login.py
index 9536e8ade6..5669ecb724 100644
--- a/synapse/rest/client/v1/login.py
+++ b/synapse/rest/client/v1/login.py
@@ -85,7 +85,6 @@ def login_id_thirdparty_from_phone(identifier):
 
 class LoginRestServlet(ClientV1RestServlet):
     PATTERNS = client_path_patterns("/login$")
-    PASS_TYPE = "m.login.password"
     SAML2_TYPE = "m.login.saml2"
     CAS_TYPE = "m.login.cas"
     TOKEN_TYPE = "m.login.token"
@@ -94,7 +93,6 @@ class LoginRestServlet(ClientV1RestServlet):
     def __init__(self, hs):
         super(LoginRestServlet, self).__init__(hs)
         self.idp_redirect_url = hs.config.saml2_idp_redirect_url
-        self.password_enabled = hs.config.password_enabled
         self.saml2_enabled = hs.config.saml2_enabled
         self.jwt_enabled = hs.config.jwt_enabled
         self.jwt_secret = hs.config.jwt_secret
@@ -121,8 +119,10 @@ class LoginRestServlet(ClientV1RestServlet):
             # fall back to the fallback API if they don't understand one of the
             # login flow types returned.
             flows.append({"type": LoginRestServlet.TOKEN_TYPE})
-        if self.password_enabled:
-            flows.append({"type": LoginRestServlet.PASS_TYPE})
+
+        flows.extend((
+            {"type": t} for t in self.auth_handler.get_supported_login_types()
+        ))
 
         return (200, {"flows": flows})
 
@@ -133,14 +133,8 @@ class LoginRestServlet(ClientV1RestServlet):
     def on_POST(self, request):
         login_submission = parse_json_object_from_request(request)
         try:
-            if login_submission["type"] == LoginRestServlet.PASS_TYPE:
-                if not self.password_enabled:
-                    raise SynapseError(400, "Password login has been disabled.")
-
-                result = yield self.do_password_login(login_submission)
-                defer.returnValue(result)
-            elif self.saml2_enabled and (login_submission["type"] ==
-                                         LoginRestServlet.SAML2_TYPE):
+            if self.saml2_enabled and (login_submission["type"] ==
+                                       LoginRestServlet.SAML2_TYPE):
                 relay_state = ""
                 if "relay_state" in login_submission:
                     relay_state = "&RelayState=" + urllib.quote(
@@ -157,15 +151,31 @@ class LoginRestServlet(ClientV1RestServlet):
                 result = yield self.do_token_login(login_submission)
                 defer.returnValue(result)
             else:
-                raise SynapseError(400, "Bad login type.")
+                result = yield self._do_other_login(login_submission)
+                defer.returnValue(result)
         except KeyError:
             raise SynapseError(400, "Missing JSON keys.")
 
     @defer.inlineCallbacks
-    def do_password_login(self, login_submission):
-        if "password" not in login_submission:
-            raise SynapseError(400, "Missing parameter: password")
+    def _do_other_login(self, login_submission):
+        """Handle non-token/saml/jwt logins
 
+        Args:
+            login_submission:
+
+        Returns:
+            (int, object): HTTP code/response
+        """
+        # Log the request we got, but only certain fields to minimise the chance of
+        # logging someone's password (even if they accidentally put it in the wrong
+        # field)
+        logger.info(
+            "Got login request with identifier: %r, medium: %r, address: %r, user: %r",
+            login_submission.get('identifier'),
+            login_submission.get('medium'),
+            login_submission.get('address'),
+            login_submission.get('user'),
+        )
         login_submission_legacy_convert(login_submission)
 
         if "identifier" not in login_submission:
@@ -208,30 +218,29 @@ class LoginRestServlet(ClientV1RestServlet):
         if "user" not in identifier:
             raise SynapseError(400, "User identifier is missing 'user' key")
 
-        user_id = identifier["user"]
-
-        if not user_id.startswith('@'):
-            user_id = UserID(
-                user_id, self.hs.hostname
-            ).to_string()
-
         auth_handler = self.auth_handler
-        user_id = yield auth_handler.validate_password_login(
-            user_id=user_id,
-            password=login_submission["password"],
+        canonical_user_id, callback = yield auth_handler.validate_login(
+            identifier["user"],
+            login_submission,
+        )
+
+        device_id = yield self._register_device(
+            canonical_user_id, login_submission,
         )
-        device_id = yield self._register_device(user_id, login_submission)
         access_token = yield auth_handler.get_access_token_for_user_id(
-            user_id, device_id,
-            login_submission.get("initial_device_display_name"),
+            canonical_user_id, device_id,
         )
+
         result = {
-            "user_id": user_id,  # may have changed
+            "user_id": canonical_user_id,
             "access_token": access_token,
             "home_server": self.hs.hostname,
             "device_id": device_id,
         }
 
+        if callback is not None:
+            yield callback(result)
+
         defer.returnValue((200, result))
 
     @defer.inlineCallbacks
@@ -244,7 +253,6 @@ class LoginRestServlet(ClientV1RestServlet):
         device_id = yield self._register_device(user_id, login_submission)
         access_token = yield auth_handler.get_access_token_for_user_id(
             user_id, device_id,
-            login_submission.get("initial_device_display_name"),
         )
         result = {
             "user_id": user_id,  # may have changed
@@ -287,7 +295,6 @@ class LoginRestServlet(ClientV1RestServlet):
             )
             access_token = yield auth_handler.get_access_token_for_user_id(
                 registered_user_id, device_id,
-                login_submission.get("initial_device_display_name"),
             )
 
             result = {
diff --git a/synapse/rest/client/v1/logout.py b/synapse/rest/client/v1/logout.py
index 1358d0acab..6add754782 100644
--- a/synapse/rest/client/v1/logout.py
+++ b/synapse/rest/client/v1/logout.py
@@ -30,7 +30,7 @@ class LogoutRestServlet(ClientV1RestServlet):
 
     def __init__(self, hs):
         super(LogoutRestServlet, self).__init__(hs)
-        self.store = hs.get_datastore()
+        self._auth_handler = hs.get_auth_handler()
 
     def on_OPTIONS(self, request):
         return (200, {})
@@ -38,7 +38,7 @@ class LogoutRestServlet(ClientV1RestServlet):
     @defer.inlineCallbacks
     def on_POST(self, request):
         access_token = get_access_token_from_request(request)
-        yield self.store.delete_access_token(access_token)
+        yield self._auth_handler.delete_access_token(access_token)
         defer.returnValue((200, {}))
 
 
@@ -47,8 +47,8 @@ class LogoutAllRestServlet(ClientV1RestServlet):
 
     def __init__(self, hs):
         super(LogoutAllRestServlet, self).__init__(hs)
-        self.store = hs.get_datastore()
         self.auth = hs.get_auth()
+        self._auth_handler = hs.get_auth_handler()
 
     def on_OPTIONS(self, request):
         return (200, {})
@@ -57,7 +57,7 @@ class LogoutAllRestServlet(ClientV1RestServlet):
     def on_POST(self, request):
         requester = yield self.auth.get_user_by_req(request)
         user_id = requester.user.to_string()
-        yield self.store.user_delete_access_tokens(user_id)
+        yield self._auth_handler.delete_access_tokens_for_user(user_id)
         defer.returnValue((200, {}))
 
 
diff --git a/synapse/rest/client/v2_alpha/account.py b/synapse/rest/client/v2_alpha/account.py
index 4990b22b9f..3062e04c59 100644
--- a/synapse/rest/client/v2_alpha/account.py
+++ b/synapse/rest/client/v2_alpha/account.py
@@ -13,22 +13,21 @@
 # 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 twisted.internet import defer
 
+from synapse.api.auth import has_access_token
 from synapse.api.constants import LoginType
-from synapse.api.errors import LoginError, SynapseError, Codes
+from synapse.api.errors import Codes, LoginError, SynapseError
 from synapse.http.servlet import (
-    RestServlet, parse_json_object_from_request, assert_params_in_request
+    RestServlet, assert_params_in_request,
+    parse_json_object_from_request,
 )
 from synapse.util.async import run_on_reactor
 from synapse.util.msisdn import phone_number_to_msisdn
-
 from ._base import client_v2_patterns
 
-import logging
-
-
 logger = logging.getLogger(__name__)
 
 
@@ -163,7 +162,6 @@ class DeactivateAccountRestServlet(RestServlet):
 
     def __init__(self, hs):
         self.hs = hs
-        self.store = hs.get_datastore()
         self.auth = hs.get_auth()
         self.auth_handler = hs.get_auth_handler()
         super(DeactivateAccountRestServlet, self).__init__()
@@ -172,6 +170,20 @@ class DeactivateAccountRestServlet(RestServlet):
     def on_POST(self, request):
         body = parse_json_object_from_request(request)
 
+        # if the caller provides an access token, it ought to be valid.
+        requester = None
+        if has_access_token(request):
+            requester = yield self.auth.get_user_by_req(
+                request,
+            )  # type: synapse.types.Requester
+
+        # allow ASes to dectivate their own users
+        if requester and requester.app_service:
+            yield self.auth_handler.deactivate_account(
+                requester.user.to_string()
+            )
+            defer.returnValue((200, {}))
+
         authed, result, params, _ = yield self.auth_handler.check_auth([
             [LoginType.PASSWORD],
         ], body, self.hs.get_ip_from_request(request))
@@ -179,25 +191,22 @@ class DeactivateAccountRestServlet(RestServlet):
         if not authed:
             defer.returnValue((401, result))
 
-        user_id = None
-        requester = None
-
         if LoginType.PASSWORD in result:
+            user_id = result[LoginType.PASSWORD]
             # if using password, they should also be logged in
-            requester = yield self.auth.get_user_by_req(request)
-            user_id = requester.user.to_string()
-            if user_id != result[LoginType.PASSWORD]:
+            if requester is None:
+                raise SynapseError(
+                    400,
+                    "Deactivate account requires an access_token",
+                    errcode=Codes.MISSING_TOKEN
+                )
+            if requester.user.to_string() != user_id:
                 raise LoginError(400, "", Codes.UNKNOWN)
         else:
             logger.error("Auth succeeded but no known type!", result.keys())
             raise SynapseError(500, "", Codes.UNKNOWN)
 
-        # FIXME: Theoretically there is a race here wherein user resets password
-        # using threepid.
-        yield self.store.user_delete_access_tokens(user_id)
-        yield self.store.user_delete_threepids(user_id)
-        yield self.store.user_set_password_hash(user_id, None)
-
+        yield self.auth_handler.deactivate_account(user_id)
         defer.returnValue((200, {}))
 
 
diff --git a/synapse/rest/client/v2_alpha/devices.py b/synapse/rest/client/v2_alpha/devices.py
index b57ba95d24..5321e5abbb 100644
--- a/synapse/rest/client/v2_alpha/devices.py
+++ b/synapse/rest/client/v2_alpha/devices.py
@@ -25,7 +25,7 @@ logger = logging.getLogger(__name__)
 
 
 class DevicesRestServlet(servlet.RestServlet):
-    PATTERNS = client_v2_patterns("/devices$", releases=[], v2_alpha=False)
+    PATTERNS = client_v2_patterns("/devices$", v2_alpha=False)
 
     def __init__(self, hs):
         """
@@ -51,7 +51,7 @@ class DeleteDevicesRestServlet(servlet.RestServlet):
     API for bulk deletion of devices. Accepts a JSON object with a devices
     key which lists the device_ids to delete. Requires user interactive auth.
     """
-    PATTERNS = client_v2_patterns("/delete_devices", releases=[], v2_alpha=False)
+    PATTERNS = client_v2_patterns("/delete_devices", v2_alpha=False)
 
     def __init__(self, hs):
         super(DeleteDevicesRestServlet, self).__init__()
@@ -93,8 +93,7 @@ class DeleteDevicesRestServlet(servlet.RestServlet):
 
 
 class DeviceRestServlet(servlet.RestServlet):
-    PATTERNS = client_v2_patterns("/devices/(?P<device_id>[^/]*)$",
-                                  releases=[], v2_alpha=False)
+    PATTERNS = client_v2_patterns("/devices/(?P<device_id>[^/]*)$", v2_alpha=False)
 
     def __init__(self, hs):
         """
@@ -118,6 +117,8 @@ class DeviceRestServlet(servlet.RestServlet):
 
     @defer.inlineCallbacks
     def on_DELETE(self, request, device_id):
+        requester = yield self.auth.get_user_by_req(request)
+
         try:
             body = servlet.parse_json_object_from_request(request)
 
@@ -136,11 +137,12 @@ class DeviceRestServlet(servlet.RestServlet):
         if not authed:
             defer.returnValue((401, result))
 
-        requester = yield self.auth.get_user_by_req(request)
-        yield self.device_handler.delete_device(
-            requester.user.to_string(),
-            device_id,
-        )
+        # check that the UI auth matched the access token
+        user_id = result[constants.LoginType.PASSWORD]
+        if user_id != requester.user.to_string():
+            raise errors.AuthError(403, "Invalid auth")
+
+        yield self.device_handler.delete_device(user_id, device_id)
         defer.returnValue((200, {}))
 
     @defer.inlineCallbacks
diff --git a/synapse/rest/client/v2_alpha/groups.py b/synapse/rest/client/v2_alpha/groups.py
index 100f47ca9e..792608cd48 100644
--- a/synapse/rest/client/v2_alpha/groups.py
+++ b/synapse/rest/client/v2_alpha/groups.py
@@ -39,20 +39,23 @@ class GroupServlet(RestServlet):
     @defer.inlineCallbacks
     def on_GET(self, request, group_id):
         requester = yield self.auth.get_user_by_req(request)
-        user_id = requester.user.to_string()
+        requester_user_id = requester.user.to_string()
 
-        group_description = yield self.groups_handler.get_group_profile(group_id, user_id)
+        group_description = yield self.groups_handler.get_group_profile(
+            group_id,
+            requester_user_id,
+        )
 
         defer.returnValue((200, group_description))
 
     @defer.inlineCallbacks
     def on_POST(self, request, group_id):
         requester = yield self.auth.get_user_by_req(request)
-        user_id = requester.user.to_string()
+        requester_user_id = requester.user.to_string()
 
         content = parse_json_object_from_request(request)
         yield self.groups_handler.update_group_profile(
-            group_id, user_id, content,
+            group_id, requester_user_id, content,
         )
 
         defer.returnValue((200, {}))
@@ -72,9 +75,12 @@ class GroupSummaryServlet(RestServlet):
     @defer.inlineCallbacks
     def on_GET(self, request, group_id):
         requester = yield self.auth.get_user_by_req(request)
-        user_id = requester.user.to_string()
+        requester_user_id = requester.user.to_string()
 
-        get_group_summary = yield self.groups_handler.get_group_summary(group_id, user_id)
+        get_group_summary = yield self.groups_handler.get_group_summary(
+            group_id,
+            requester_user_id,
+        )
 
         defer.returnValue((200, get_group_summary))
 
@@ -101,11 +107,11 @@ class GroupSummaryRoomsCatServlet(RestServlet):
     @defer.inlineCallbacks
     def on_PUT(self, request, group_id, category_id, room_id):
         requester = yield self.auth.get_user_by_req(request)
-        user_id = requester.user.to_string()
+        requester_user_id = requester.user.to_string()
 
         content = parse_json_object_from_request(request)
         resp = yield self.groups_handler.update_group_summary_room(
-            group_id, user_id,
+            group_id, requester_user_id,
             room_id=room_id,
             category_id=category_id,
             content=content,
@@ -116,10 +122,10 @@ class GroupSummaryRoomsCatServlet(RestServlet):
     @defer.inlineCallbacks
     def on_DELETE(self, request, group_id, category_id, room_id):
         requester = yield self.auth.get_user_by_req(request)
-        user_id = requester.user.to_string()
+        requester_user_id = requester.user.to_string()
 
         resp = yield self.groups_handler.delete_group_summary_room(
-            group_id, user_id,
+            group_id, requester_user_id,
             room_id=room_id,
             category_id=category_id,
         )
@@ -143,10 +149,10 @@ class GroupCategoryServlet(RestServlet):
     @defer.inlineCallbacks
     def on_GET(self, request, group_id, category_id):
         requester = yield self.auth.get_user_by_req(request)
-        user_id = requester.user.to_string()
+        requester_user_id = requester.user.to_string()
 
         category = yield self.groups_handler.get_group_category(
-            group_id, user_id,
+            group_id, requester_user_id,
             category_id=category_id,
         )
 
@@ -155,11 +161,11 @@ class GroupCategoryServlet(RestServlet):
     @defer.inlineCallbacks
     def on_PUT(self, request, group_id, category_id):
         requester = yield self.auth.get_user_by_req(request)
-        user_id = requester.user.to_string()
+        requester_user_id = requester.user.to_string()
 
         content = parse_json_object_from_request(request)
         resp = yield self.groups_handler.update_group_category(
-            group_id, user_id,
+            group_id, requester_user_id,
             category_id=category_id,
             content=content,
         )
@@ -169,10 +175,10 @@ class GroupCategoryServlet(RestServlet):
     @defer.inlineCallbacks
     def on_DELETE(self, request, group_id, category_id):
         requester = yield self.auth.get_user_by_req(request)
-        user_id = requester.user.to_string()
+        requester_user_id = requester.user.to_string()
 
         resp = yield self.groups_handler.delete_group_category(
-            group_id, user_id,
+            group_id, requester_user_id,
             category_id=category_id,
         )
 
@@ -195,10 +201,10 @@ class GroupCategoriesServlet(RestServlet):
     @defer.inlineCallbacks
     def on_GET(self, request, group_id):
         requester = yield self.auth.get_user_by_req(request)
-        user_id = requester.user.to_string()
+        requester_user_id = requester.user.to_string()
 
         category = yield self.groups_handler.get_group_categories(
-            group_id, user_id,
+            group_id, requester_user_id,
         )
 
         defer.returnValue((200, category))
@@ -220,10 +226,10 @@ class GroupRoleServlet(RestServlet):
     @defer.inlineCallbacks
     def on_GET(self, request, group_id, role_id):
         requester = yield self.auth.get_user_by_req(request)
-        user_id = requester.user.to_string()
+        requester_user_id = requester.user.to_string()
 
         category = yield self.groups_handler.get_group_role(
-            group_id, user_id,
+            group_id, requester_user_id,
             role_id=role_id,
         )
 
@@ -232,11 +238,11 @@ class GroupRoleServlet(RestServlet):
     @defer.inlineCallbacks
     def on_PUT(self, request, group_id, role_id):
         requester = yield self.auth.get_user_by_req(request)
-        user_id = requester.user.to_string()
+        requester_user_id = requester.user.to_string()
 
         content = parse_json_object_from_request(request)
         resp = yield self.groups_handler.update_group_role(
-            group_id, user_id,
+            group_id, requester_user_id,
             role_id=role_id,
             content=content,
         )
@@ -246,10 +252,10 @@ class GroupRoleServlet(RestServlet):
     @defer.inlineCallbacks
     def on_DELETE(self, request, group_id, role_id):
         requester = yield self.auth.get_user_by_req(request)
-        user_id = requester.user.to_string()
+        requester_user_id = requester.user.to_string()
 
         resp = yield self.groups_handler.delete_group_role(
-            group_id, user_id,
+            group_id, requester_user_id,
             role_id=role_id,
         )
 
@@ -272,10 +278,10 @@ class GroupRolesServlet(RestServlet):
     @defer.inlineCallbacks
     def on_GET(self, request, group_id):
         requester = yield self.auth.get_user_by_req(request)
-        user_id = requester.user.to_string()
+        requester_user_id = requester.user.to_string()
 
         category = yield self.groups_handler.get_group_roles(
-            group_id, user_id,
+            group_id, requester_user_id,
         )
 
         defer.returnValue((200, category))
@@ -343,9 +349,9 @@ class GroupRoomServlet(RestServlet):
     @defer.inlineCallbacks
     def on_GET(self, request, group_id):
         requester = yield self.auth.get_user_by_req(request)
-        user_id = requester.user.to_string()
+        requester_user_id = requester.user.to_string()
 
-        result = yield self.groups_handler.get_rooms_in_group(group_id, user_id)
+        result = yield self.groups_handler.get_rooms_in_group(group_id, requester_user_id)
 
         defer.returnValue((200, result))
 
@@ -364,9 +370,9 @@ class GroupUsersServlet(RestServlet):
     @defer.inlineCallbacks
     def on_GET(self, request, group_id):
         requester = yield self.auth.get_user_by_req(request)
-        user_id = requester.user.to_string()
+        requester_user_id = requester.user.to_string()
 
-        result = yield self.groups_handler.get_users_in_group(group_id, user_id)
+        result = yield self.groups_handler.get_users_in_group(group_id, requester_user_id)
 
         defer.returnValue((200, result))
 
@@ -385,9 +391,12 @@ class GroupInvitedUsersServlet(RestServlet):
     @defer.inlineCallbacks
     def on_GET(self, request, group_id):
         requester = yield self.auth.get_user_by_req(request)
-        user_id = requester.user.to_string()
+        requester_user_id = requester.user.to_string()
 
-        result = yield self.groups_handler.get_invited_users_in_group(group_id, user_id)
+        result = yield self.groups_handler.get_invited_users_in_group(
+            group_id,
+            requester_user_id,
+        )
 
         defer.returnValue((200, result))
 
@@ -407,14 +416,18 @@ class GroupCreateServlet(RestServlet):
     @defer.inlineCallbacks
     def on_POST(self, request):
         requester = yield self.auth.get_user_by_req(request)
-        user_id = requester.user.to_string()
+        requester_user_id = requester.user.to_string()
 
         # TODO: Create group on remote server
         content = parse_json_object_from_request(request)
         localpart = content.pop("localpart")
         group_id = GroupID(localpart, self.server_name).to_string()
 
-        result = yield self.groups_handler.create_group(group_id, user_id, content)
+        result = yield self.groups_handler.create_group(
+            group_id,
+            requester_user_id,
+            content,
+        )
 
         defer.returnValue((200, result))
 
@@ -435,11 +448,11 @@ class GroupAdminRoomsServlet(RestServlet):
     @defer.inlineCallbacks
     def on_PUT(self, request, group_id, room_id):
         requester = yield self.auth.get_user_by_req(request)
-        user_id = requester.user.to_string()
+        requester_user_id = requester.user.to_string()
 
         content = parse_json_object_from_request(request)
-        result = yield self.groups_handler.add_room_to_group(
-            group_id, user_id, room_id, content,
+        result = yield self.groups_handler.update_room_group_association(
+            group_id, requester_user_id, room_id, content,
         )
 
         defer.returnValue((200, result))
@@ -447,10 +460,10 @@ class GroupAdminRoomsServlet(RestServlet):
     @defer.inlineCallbacks
     def on_DELETE(self, request, group_id, room_id):
         requester = yield self.auth.get_user_by_req(request)
-        user_id = requester.user.to_string()
+        requester_user_id = requester.user.to_string()
 
-        result = yield self.groups_handler.remove_room_from_group(
-            group_id, user_id, room_id,
+        result = yield self.groups_handler.delete_room_group_association(
+            group_id, requester_user_id, room_id,
         )
 
         defer.returnValue((200, result))
@@ -685,9 +698,9 @@ class GroupsForUserServlet(RestServlet):
     @defer.inlineCallbacks
     def on_GET(self, request):
         requester = yield self.auth.get_user_by_req(request)
-        user_id = requester.user.to_string()
+        requester_user_id = requester.user.to_string()
 
-        result = yield self.groups_handler.get_joined_groups(user_id)
+        result = yield self.groups_handler.get_joined_groups(requester_user_id)
 
         defer.returnValue((200, result))
 
diff --git a/synapse/rest/client/v2_alpha/keys.py b/synapse/rest/client/v2_alpha/keys.py
index 943e87e7fd..3cc87ea63f 100644
--- a/synapse/rest/client/v2_alpha/keys.py
+++ b/synapse/rest/client/v2_alpha/keys.py
@@ -53,8 +53,7 @@ class KeyUploadServlet(RestServlet):
       },
     }
     """
-    PATTERNS = client_v2_patterns("/keys/upload(/(?P<device_id>[^/]+))?$",
-                                  releases=())
+    PATTERNS = client_v2_patterns("/keys/upload(/(?P<device_id>[^/]+))?$")
 
     def __init__(self, hs):
         """
@@ -128,10 +127,7 @@ class KeyQueryServlet(RestServlet):
     } } } } } }
     """
 
-    PATTERNS = client_v2_patterns(
-        "/keys/query$",
-        releases=()
-    )
+    PATTERNS = client_v2_patterns("/keys/query$")
 
     def __init__(self, hs):
         """
@@ -160,10 +156,7 @@ class KeyChangesServlet(RestServlet):
         200 OK
         { "changed": ["@foo:example.com"] }
     """
-    PATTERNS = client_v2_patterns(
-        "/keys/changes$",
-        releases=()
-    )
+    PATTERNS = client_v2_patterns("/keys/changes$")
 
     def __init__(self, hs):
         """
@@ -213,10 +206,7 @@ class OneTimeKeyServlet(RestServlet):
     } } } }
 
     """
-    PATTERNS = client_v2_patterns(
-        "/keys/claim$",
-        releases=()
-    )
+    PATTERNS = client_v2_patterns("/keys/claim$")
 
     def __init__(self, hs):
         super(OneTimeKeyServlet, self).__init__()
diff --git a/synapse/rest/client/v2_alpha/notifications.py b/synapse/rest/client/v2_alpha/notifications.py
index fd2a3d69d4..ec170109fe 100644
--- a/synapse/rest/client/v2_alpha/notifications.py
+++ b/synapse/rest/client/v2_alpha/notifications.py
@@ -30,7 +30,7 @@ logger = logging.getLogger(__name__)
 
 
 class NotificationsServlet(RestServlet):
-    PATTERNS = client_v2_patterns("/notifications$", releases=())
+    PATTERNS = client_v2_patterns("/notifications$")
 
     def __init__(self, hs):
         super(NotificationsServlet, self).__init__()
diff --git a/synapse/rest/client/v2_alpha/register.py b/synapse/rest/client/v2_alpha/register.py
index d9a8cdbbb5..eebd071e59 100644
--- a/synapse/rest/client/v2_alpha/register.py
+++ b/synapse/rest/client/v2_alpha/register.py
@@ -557,25 +557,28 @@ class RegisterRestServlet(RestServlet):
         Args:
             (str) user_id: full canonical @user:id
             (object) params: registration parameters, from which we pull
-                device_id and initial_device_name
+                device_id, initial_device_name and inhibit_login
         Returns:
             defer.Deferred: (object) dictionary for response from /register
         """
-        device_id = yield self._register_device(user_id, params)
+        result = {
+            "user_id": user_id,
+            "home_server": self.hs.hostname,
+        }
+        if not params.get("inhibit_login", False):
+            device_id = yield self._register_device(user_id, params)
 
-        access_token = (
-            yield self.auth_handler.get_access_token_for_user_id(
-                user_id, device_id=device_id,
-                initial_display_name=params.get("initial_device_display_name")
+            access_token = (
+                yield self.auth_handler.get_access_token_for_user_id(
+                    user_id, device_id=device_id,
+                )
             )
-        )
 
-        defer.returnValue({
-            "user_id": user_id,
-            "access_token": access_token,
-            "home_server": self.hs.hostname,
-            "device_id": device_id,
-        })
+            result.update({
+                "access_token": access_token,
+                "device_id": device_id,
+            })
+        defer.returnValue(result)
 
     def _register_device(self, user_id, params):
         """Register a device for a user.
diff --git a/synapse/rest/client/v2_alpha/sendtodevice.py b/synapse/rest/client/v2_alpha/sendtodevice.py
index d607bd2970..90bdb1db15 100644
--- a/synapse/rest/client/v2_alpha/sendtodevice.py
+++ b/synapse/rest/client/v2_alpha/sendtodevice.py
@@ -29,7 +29,7 @@ logger = logging.getLogger(__name__)
 class SendToDeviceRestServlet(servlet.RestServlet):
     PATTERNS = client_v2_patterns(
         "/sendToDevice/(?P<message_type>[^/]*)/(?P<txn_id>[^/]*)$",
-        releases=[], v2_alpha=False
+        v2_alpha=False
     )
 
     def __init__(self, hs):
diff --git a/synapse/rest/client/v2_alpha/thirdparty.py b/synapse/rest/client/v2_alpha/thirdparty.py
index 6fceb23e26..6773b9ba60 100644
--- a/synapse/rest/client/v2_alpha/thirdparty.py
+++ b/synapse/rest/client/v2_alpha/thirdparty.py
@@ -26,7 +26,7 @@ logger = logging.getLogger(__name__)
 
 
 class ThirdPartyProtocolsServlet(RestServlet):
-    PATTERNS = client_v2_patterns("/thirdparty/protocols", releases=())
+    PATTERNS = client_v2_patterns("/thirdparty/protocols")
 
     def __init__(self, hs):
         super(ThirdPartyProtocolsServlet, self).__init__()
@@ -43,8 +43,7 @@ class ThirdPartyProtocolsServlet(RestServlet):
 
 
 class ThirdPartyProtocolServlet(RestServlet):
-    PATTERNS = client_v2_patterns("/thirdparty/protocol/(?P<protocol>[^/]+)$",
-                                  releases=())
+    PATTERNS = client_v2_patterns("/thirdparty/protocol/(?P<protocol>[^/]+)$")
 
     def __init__(self, hs):
         super(ThirdPartyProtocolServlet, self).__init__()
@@ -66,8 +65,7 @@ class ThirdPartyProtocolServlet(RestServlet):
 
 
 class ThirdPartyUserServlet(RestServlet):
-    PATTERNS = client_v2_patterns("/thirdparty/user(/(?P<protocol>[^/]+))?$",
-                                  releases=())
+    PATTERNS = client_v2_patterns("/thirdparty/user(/(?P<protocol>[^/]+))?$")
 
     def __init__(self, hs):
         super(ThirdPartyUserServlet, self).__init__()
@@ -90,8 +88,7 @@ class ThirdPartyUserServlet(RestServlet):
 
 
 class ThirdPartyLocationServlet(RestServlet):
-    PATTERNS = client_v2_patterns("/thirdparty/location(/(?P<protocol>[^/]+))?$",
-                                  releases=())
+    PATTERNS = client_v2_patterns("/thirdparty/location(/(?P<protocol>[^/]+))?$")
 
     def __init__(self, hs):
         super(ThirdPartyLocationServlet, self).__init__()
diff --git a/synapse/rest/media/v1/preview_url_resource.py b/synapse/rest/media/v1/preview_url_resource.py
index 80114fca0d..7907a9d17a 100644
--- a/synapse/rest/media/v1/preview_url_resource.py
+++ b/synapse/rest/media/v1/preview_url_resource.py
@@ -520,7 +520,14 @@ def _calc_og(tree, media_uri):
             from lxml import etree
 
             TAGS_TO_REMOVE = (
-                "header", "nav", "aside", "footer", "script", "style", etree.Comment
+                "header",
+                "nav",
+                "aside",
+                "footer",
+                "script",
+                "noscript",
+                "style",
+                etree.Comment
             )
 
             # Split all the text nodes into paragraphs (by splitting on new
diff --git a/synapse/storage/group_server.py b/synapse/storage/group_server.py
index 9e63db5c6c..6b261dcc0f 100644
--- a/synapse/storage/group_server.py
+++ b/synapse/storage/group_server.py
@@ -35,7 +35,9 @@ class GroupServerStore(SQLBaseStore):
             keyvalues={
                 "group_id": group_id,
             },
-            retcols=("name", "short_description", "long_description", "avatar_url",),
+            retcols=(
+                "name", "short_description", "long_description", "avatar_url", "is_public"
+            ),
             allow_none=True,
             desc="is_user_in_group",
         )
@@ -52,7 +54,7 @@ class GroupServerStore(SQLBaseStore):
         return self._simple_select_list(
             table="group_users",
             keyvalues=keyvalues,
-            retcols=("user_id", "is_public",),
+            retcols=("user_id", "is_public", "is_admin",),
             desc="get_users_in_group",
         )
 
@@ -844,19 +846,25 @@ class GroupServerStore(SQLBaseStore):
             )
         return self.runInteraction("remove_user_from_group", _remove_user_from_group_txn)
 
-    def add_room_to_group(self, group_id, room_id, is_public):
-        return self._simple_insert(
+    def update_room_group_association(self, group_id, room_id, is_public):
+        return self._simple_upsert(
             table="group_rooms",
-            values={
+            keyvalues={
                 "group_id": group_id,
                 "room_id": room_id,
+            },
+            values={
                 "is_public": is_public,
             },
-            desc="add_room_to_group",
+            insertion_values={
+                "group_id": group_id,
+                "room_id": room_id,
+            },
+            desc="update_room_group_association",
         )
 
-    def remove_room_from_group(self, group_id, room_id):
-        def _remove_room_from_group_txn(txn):
+    def delete_room_group_association(self, group_id, room_id):
+        def _delete_room_group_association_txn(txn):
             self._simple_delete_txn(
                 txn,
                 table="group_rooms",
@@ -875,7 +883,7 @@ class GroupServerStore(SQLBaseStore):
                 },
             )
         return self.runInteraction(
-            "remove_room_from_group", _remove_room_from_group_txn,
+            "delete_room_group_association", _delete_room_group_association_txn,
         )
 
     def get_publicised_groups_for_user(self, user_id):
@@ -1026,6 +1034,7 @@ class GroupServerStore(SQLBaseStore):
                 "avatar_url": avatar_url,
                 "short_description": short_description,
                 "long_description": long_description,
+                "is_public": True,
             },
             desc="create_group",
         )
@@ -1086,6 +1095,24 @@ class GroupServerStore(SQLBaseStore):
             desc="update_remote_attestion",
         )
 
+    def remove_attestation_renewal(self, group_id, user_id):
+        """Remove an attestation that we thought we should renew, but actually
+        shouldn't. Ideally this would never get called as we would never
+        incorrectly try and do attestations for local users on local groups.
+
+        Args:
+            group_id (str)
+            user_id (str)
+        """
+        return self._simple_delete(
+            table="group_attestations_renewals",
+            keyvalues={
+                "group_id": group_id,
+                "user_id": user_id,
+            },
+            desc="remove_attestation_renewal",
+        )
+
     @defer.inlineCallbacks
     def get_remote_attestation(self, group_id, user_id):
         """Get the attestation that proves the remote agrees that the user is
diff --git a/synapse/storage/prepare_database.py b/synapse/storage/prepare_database.py
index 817c2185c8..d1691bbac2 100644
--- a/synapse/storage/prepare_database.py
+++ b/synapse/storage/prepare_database.py
@@ -25,7 +25,7 @@ logger = logging.getLogger(__name__)
 
 # Remember to update this number every time a change is made to database
 # schema files, so the users will be informed on server restarts.
-SCHEMA_VERSION = 45
+SCHEMA_VERSION = 46
 
 dir_path = os.path.abspath(os.path.dirname(__file__))
 
@@ -44,6 +44,13 @@ def prepare_database(db_conn, database_engine, config):
 
     If `config` is None then prepare_database will assert that no upgrade is
     necessary, *or* will create a fresh database if the database is empty.
+
+    Args:
+        db_conn:
+        database_engine:
+        config (synapse.config.homeserver.HomeServerConfig|None):
+            application config, or None if we are connecting to an existing
+            database which we expect to be configured already
     """
     try:
         cur = db_conn.cursor()
@@ -64,6 +71,10 @@ def prepare_database(db_conn, database_engine, config):
         else:
             _setup_new_database(cur, database_engine)
 
+        # check if any of our configured dynamic modules want a database
+        if config is not None:
+            _apply_module_schemas(cur, database_engine, config)
+
         cur.close()
         db_conn.commit()
     except Exception:
@@ -283,6 +294,65 @@ def _upgrade_existing_database(cur, current_version, applied_delta_files,
             )
 
 
+def _apply_module_schemas(txn, database_engine, config):
+    """Apply the module schemas for the dynamic modules, if any
+
+    Args:
+        cur: database cursor
+        database_engine: synapse database engine class
+        config (synapse.config.homeserver.HomeServerConfig):
+            application config
+    """
+    for (mod, _config) in config.password_providers:
+        if not hasattr(mod, 'get_db_schema_files'):
+            continue
+        modname = ".".join((mod.__module__, mod.__name__))
+        _apply_module_schema_files(
+            txn, database_engine, modname, mod.get_db_schema_files(),
+        )
+
+
+def _apply_module_schema_files(cur, database_engine, modname, names_and_streams):
+    """Apply the module schemas for a single module
+
+    Args:
+        cur: database cursor
+        database_engine: synapse database engine class
+        modname (str): fully qualified name of the module
+        names_and_streams (Iterable[(str, file)]): the names and streams of
+            schemas to be applied
+    """
+    cur.execute(
+        database_engine.convert_param_style(
+            "SELECT file FROM applied_module_schemas WHERE module_name = ?"
+        ),
+        (modname,)
+    )
+    applied_deltas = set(d for d, in cur)
+    for (name, stream) in names_and_streams:
+        if name in applied_deltas:
+            continue
+
+        root_name, ext = os.path.splitext(name)
+        if ext != '.sql':
+            raise PrepareDatabaseException(
+                "only .sql files are currently supported for module schemas",
+            )
+
+        logger.info("applying schema %s for %s", name, modname)
+        for statement in get_statements(stream):
+            cur.execute(statement)
+
+        # Mark as done.
+        cur.execute(
+            database_engine.convert_param_style(
+                "INSERT INTO applied_module_schemas (module_name, file)"
+                " VALUES (?,?)",
+            ),
+            (modname, name)
+        )
+
+
 def get_statements(f):
     statement_buffer = ""
     in_comment = False  # If we're in a /* ... */ style comment
diff --git a/synapse/storage/registration.py b/synapse/storage/registration.py
index 20acd58fcf..9c4f61da76 100644
--- a/synapse/storage/registration.py
+++ b/synapse/storage/registration.py
@@ -36,12 +36,15 @@ class RegistrationStore(background_updates.BackgroundUpdateStore):
             columns=["user_id", "device_id"],
         )
 
-        self.register_background_index_update(
-            "refresh_tokens_device_index",
-            index_name="refresh_tokens_device_id",
-            table="refresh_tokens",
-            columns=["user_id", "device_id"],
-        )
+        # we no longer use refresh tokens, but it's possible that some people
+        # might have a background update queued to build this index. Just
+        # clear the background update.
+        @defer.inlineCallbacks
+        def noop_update(progress, batch_size):
+            yield self._end_background_update("refresh_tokens_device_index")
+            defer.returnValue(1)
+        self.register_background_update_handler(
+            "refresh_tokens_device_index", noop_update)
 
     @defer.inlineCallbacks
     def add_access_token_to_user(self, user_id, token, device_id=None):
@@ -177,9 +180,11 @@ class RegistrationStore(background_updates.BackgroundUpdateStore):
             )
 
         if create_profile_with_localpart:
+            # set a default displayname serverside to avoid ugly race
+            # between auto-joins and clients trying to set displaynames
             txn.execute(
-                "INSERT INTO profiles(user_id) VALUES (?)",
-                (create_profile_with_localpart,)
+                "INSERT INTO profiles(user_id, displayname) VALUES (?,?)",
+                (create_profile_with_localpart, create_profile_with_localpart)
             )
 
         self._invalidate_cache_and_stream(
@@ -238,10 +243,9 @@ class RegistrationStore(background_updates.BackgroundUpdateStore):
 
     @defer.inlineCallbacks
     def user_delete_access_tokens(self, user_id, except_token_id=None,
-                                  device_id=None,
-                                  delete_refresh_tokens=False):
+                                  device_id=None):
         """
-        Invalidate access/refresh tokens belonging to a user
+        Invalidate access tokens belonging to a user
 
         Args:
             user_id (str):  ID of user the tokens belong to
@@ -250,10 +254,9 @@ class RegistrationStore(background_updates.BackgroundUpdateStore):
             device_id (str|None):  ID of device the tokens are associated with.
                 If None, tokens associated with any device (or no device) will
                 be deleted
-            delete_refresh_tokens (bool):  True to delete refresh tokens as
-                well as access tokens.
         Returns:
-            defer.Deferred:
+            defer.Deferred[list[str, str|None]]: a list of the deleted tokens
+                and device IDs
         """
         def f(txn):
             keyvalues = {
@@ -262,13 +265,6 @@ class RegistrationStore(background_updates.BackgroundUpdateStore):
             if device_id is not None:
                 keyvalues["device_id"] = device_id
 
-            if delete_refresh_tokens:
-                self._simple_delete_txn(
-                    txn,
-                    table="refresh_tokens",
-                    keyvalues=keyvalues,
-                )
-
             items = keyvalues.items()
             where_clause = " AND ".join(k + " = ?" for k, _ in items)
             values = [v for _, v in items]
@@ -277,14 +273,14 @@ class RegistrationStore(background_updates.BackgroundUpdateStore):
                 values.append(except_token_id)
 
             txn.execute(
-                "SELECT token FROM access_tokens WHERE %s" % where_clause,
+                "SELECT token, device_id FROM access_tokens WHERE %s" % where_clause,
                 values
             )
-            rows = self.cursor_to_dict(txn)
+            tokens_and_devices = [(r[0], r[1]) for r in txn]
 
-            for row in rows:
+            for token, _ in tokens_and_devices:
                 self._invalidate_cache_and_stream(
-                    txn, self.get_user_by_access_token, (row["token"],)
+                    txn, self.get_user_by_access_token, (token,)
                 )
 
             txn.execute(
@@ -292,6 +288,8 @@ class RegistrationStore(background_updates.BackgroundUpdateStore):
                 values
             )
 
+            return tokens_and_devices
+
         yield self.runInteraction(
             "user_delete_access_tokens", f,
         )
diff --git a/synapse/storage/schema/delta/23/refresh_tokens.sql b/synapse/storage/schema/delta/23/refresh_tokens.sql
deleted file mode 100644
index 34db0cf12b..0000000000
--- a/synapse/storage/schema/delta/23/refresh_tokens.sql
+++ /dev/null
@@ -1,21 +0,0 @@
-/* Copyright 2015, 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.
- */
-
-CREATE TABLE IF NOT EXISTS refresh_tokens(
-    id INTEGER PRIMARY KEY,
-    token TEXT NOT NULL,
-    user_id TEXT NOT NULL,
-    UNIQUE (token)
-);
diff --git a/synapse/storage/schema/delta/33/refreshtoken_device_index.sql b/synapse/storage/schema/delta/33/refreshtoken_device_index.sql
deleted file mode 100644
index bb225dafbf..0000000000
--- a/synapse/storage/schema/delta/33/refreshtoken_device_index.sql
+++ /dev/null
@@ -1,17 +0,0 @@
-/* Copyright 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.
- */
-
-INSERT INTO background_updates (update_name, progress_json) VALUES
-  ('refresh_tokens_device_index', '{}');
diff --git a/synapse/storage/schema/delta/33/refreshtoken_device.sql b/synapse/storage/schema/delta/46/drop_refresh_tokens.sql
index 290bd6da86..68c48a89a9 100644
--- a/synapse/storage/schema/delta/33/refreshtoken_device.sql
+++ b/synapse/storage/schema/delta/46/drop_refresh_tokens.sql
@@ -1,4 +1,4 @@
-/* Copyright 2016 OpenMarket Ltd
+/* Copyright 2017 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.
@@ -13,4 +13,5 @@
  * limitations under the License.
  */
 
-ALTER TABLE refresh_tokens ADD COLUMN device_id TEXT;
+/* we no longer use (or create) the refresh_tokens table */
+DROP TABLE IF EXISTS refresh_tokens;
diff --git a/synapse/storage/schema/delta/46/group_server.sql b/synapse/storage/schema/delta/46/group_server.sql
new file mode 100644
index 0000000000..e754b554f8
--- /dev/null
+++ b/synapse/storage/schema/delta/46/group_server.sql
@@ -0,0 +1,32 @@
+/* Copyright 2017 Vector Creations 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.
+ */
+
+CREATE TABLE groups_new (
+    group_id TEXT NOT NULL,
+    name TEXT,  -- the display name of the room
+    avatar_url TEXT,
+    short_description TEXT,
+    long_description TEXT,
+    is_public BOOL NOT NULL -- whether non-members can access group APIs
+);
+
+-- NB: awful hack to get the default to be true on postgres and 1 on sqlite
+INSERT INTO groups_new
+    SELECT group_id, name, avatar_url, short_description, long_description, (1=1) FROM groups;
+
+DROP TABLE groups;
+ALTER TABLE groups_new RENAME TO groups;
+
+CREATE UNIQUE INDEX groups_idx ON groups(group_id);
diff --git a/synapse/storage/schema/schema_version.sql b/synapse/storage/schema/schema_version.sql
index a7ade69986..42e5cb6df5 100644
--- a/synapse/storage/schema/schema_version.sql
+++ b/synapse/storage/schema/schema_version.sql
@@ -25,3 +25,10 @@ CREATE TABLE IF NOT EXISTS applied_schema_deltas(
     file TEXT NOT NULL,
     UNIQUE(version, file)
 );
+
+-- a list of schema files we have loaded on behalf of dynamic modules
+CREATE TABLE IF NOT EXISTS applied_module_schemas(
+    module_name TEXT NOT NULL,
+    file TEXT NOT NULL,
+    UNIQUE(module_name, file)
+);
diff --git a/synapse/util/async.py b/synapse/util/async.py
index 1a884e96ee..e786fb38a9 100644
--- a/synapse/util/async.py
+++ b/synapse/util/async.py
@@ -278,8 +278,13 @@ class Limiter(object):
         if entry[0] >= self.max_count:
             new_defer = defer.Deferred()
             entry[1].append(new_defer)
+
+            logger.info("Waiting to acquire limiter lock for key %r", key)
             with PreserveLoggingContext():
                 yield new_defer
+            logger.info("Acquired limiter lock for key %r", key)
+        else:
+            logger.info("Acquired uncontended limiter lock for key %r", key)
 
         entry[0] += 1
 
@@ -288,16 +293,21 @@ class Limiter(object):
             try:
                 yield
             finally:
+                logger.info("Releasing limiter lock for key %r", key)
+
                 # We've finished executing so check if there are any things
                 # blocked waiting to execute and start one of them
                 entry[0] -= 1
-                try:
-                    entry[1].pop(0).callback(None)
-                except IndexError:
-                    # If nothing else is executing for this key then remove it
-                    # from the map
-                    if entry[0] == 0:
-                        self.key_to_defer.pop(key, None)
+
+                if entry[1]:
+                    next_def = entry[1].pop(0)
+
+                    with PreserveLoggingContext():
+                        next_def.callback(None)
+                elif entry[0] == 0:
+                    # We were the last thing for this key: remove it from the
+                    # map.
+                    del self.key_to_defer[key]
 
         defer.returnValue(_ctx_manager())