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-rw-r--r--docs/code_style.rst7
-rw-r--r--docs/turn-howto.rst19
-rwxr-xr-xjenkins-dendron-postgres.sh3
-rwxr-xr-xjenkins-postgres.sh3
-rwxr-xr-xjenkins-sqlite.sh5
-rw-r--r--res/templates/notif_mail.html2
-rwxr-xr-xscripts/hash_password18
-rwxr-xr-xscripts/register_new_matrix_user32
-rw-r--r--synapse/api/errors.py3
-rwxr-xr-xsynapse/app/homeserver.py3
-rw-r--r--synapse/config/ldap.py102
-rw-r--r--synapse/config/password.py4
-rw-r--r--synapse/config/server.py21
-rw-r--r--synapse/federation/federation_server.py143
-rw-r--r--synapse/federation/transport/server.py2
-rw-r--r--synapse/handlers/auth.py209
-rw-r--r--synapse/handlers/federation.py2
-rw-r--r--synapse/handlers/identity.py41
-rw-r--r--synapse/handlers/message.py77
-rw-r--r--synapse/handlers/register.py9
-rw-r--r--synapse/push/httppusher.py9
-rw-r--r--synapse/push/push_tools.py32
-rw-r--r--synapse/python_dependencies.py3
-rw-r--r--synapse/replication/slave/storage/events.py9
-rw-r--r--synapse/rest/client/v1/admin.py77
-rw-r--r--synapse/rest/client/v1/register.py25
-rw-r--r--synapse/rest/media/v0/content_repository.py112
-rw-r--r--synapse/rest/media/v1/filepath.py6
-rw-r--r--synapse/rest/media/v1/media_repository.py91
-rw-r--r--synapse/server.py5
-rw-r--r--synapse/storage/_base.py5
-rw-r--r--synapse/storage/event_push_actions.py37
-rw-r--r--synapse/storage/events.py158
-rw-r--r--synapse/storage/media_repository.py44
-rw-r--r--synapse/storage/prepare_database.py2
-rw-r--r--synapse/storage/registration.py61
-rw-r--r--synapse/storage/room.py44
-rw-r--r--synapse/storage/schema/delta/33/remote_media_ts.py31
-rw-r--r--synapse/storage/stream.py148
-rw-r--r--synapse/util/async.py82
-rw-r--r--synapse/util/presentable_names.py5
-rw-r--r--tests/replication/slave/storage/test_events.py41
-rw-r--r--tests/util/test_rwlock.py85
-rw-r--r--tests/utils.py1
44 files changed, 1249 insertions, 569 deletions
diff --git a/docs/code_style.rst b/docs/code_style.rst
index dc40a7ab7b..8d73d17beb 100644
--- a/docs/code_style.rst
+++ b/docs/code_style.rst
@@ -43,7 +43,10 @@ Basically, PEP8
   together, or want to deliberately extend or preserve vertical/horizontal
   space)
 
-Comments should follow the google code style. This is so that we can generate
-documentation with sphinx (http://sphinxcontrib-napoleon.readthedocs.org/en/latest/) 
+Comments should follow the `google code style <http://google.github.io/styleguide/pyguide.html?showone=Comments#Comments>`_.
+This is so that we can generate documentation with 
+`sphinx <http://sphinxcontrib-napoleon.readthedocs.org/en/latest/>`_. See the
+`examples <http://sphinxcontrib-napoleon.readthedocs.io/en/latest/example_google.html>`_
+in the sphinx documentation.
 
 Code should pass pep8 --max-line-length=100 without any warnings.
diff --git a/docs/turn-howto.rst b/docs/turn-howto.rst
index e2c73458e2..04c0100715 100644
--- a/docs/turn-howto.rst
+++ b/docs/turn-howto.rst
@@ -9,31 +9,35 @@ the Home Server to generate credentials that are valid for use on the TURN
 server through the use of a secret shared between the Home Server and the
 TURN server.
 
-This document described how to install coturn
-(https://code.google.com/p/coturn/) which also supports the TURN REST API,
+This document describes how to install coturn
+(https://github.com/coturn/coturn) which also supports the TURN REST API,
 and integrate it with synapse.
 
 coturn Setup
 ============
 
+You may be able to setup coturn via your package manager,  or set it up manually using the usual ``configure, make, make install`` process.  
+
  1. Check out coturn::
-      svn checkout http://coturn.googlecode.com/svn/trunk/ coturn
+ 
+      git clone https://github.com/coturn/coturn.git coturn
       cd coturn
 
  2. Configure it::
+ 
       ./configure
 
-    You may need to install libevent2: if so, you should do so
+    You may need to install ``libevent2``: if so, you should do so
     in the way recommended by your operating system.
     You can ignore warnings about lack of database support: a
     database is unnecessary for this purpose.
 
  3. Build and install it::
+ 
       make
       make install
 
- 4. Make a config file in /etc/turnserver.conf. You can customise
-    a config file from turnserver.conf.default. The relevant
+ 4. Create or edit the config file in ``/etc/turnserver.conf``. The relevant
     lines, with example values, are::
 
       lt-cred-mech
@@ -41,7 +45,7 @@ coturn Setup
       static-auth-secret=[your secret key here]
       realm=turn.myserver.org
 
-    See turnserver.conf.default for explanations of the options.
+    See turnserver.conf for explanations of the options.
     One way to generate the static-auth-secret is with pwgen::
 
        pwgen -s 64 1
@@ -54,6 +58,7 @@ coturn Setup
     import your private key and certificate.
 
  7. Start the turn server::
+ 
        bin/turnserver -o
 
 
diff --git a/jenkins-dendron-postgres.sh b/jenkins-dendron-postgres.sh
index 7e6f24aa7d..50268e0982 100755
--- a/jenkins-dendron-postgres.sh
+++ b/jenkins-dendron-postgres.sh
@@ -70,6 +70,7 @@ cd sytest
 git checkout "${GIT_BRANCH}" || (echo >&2 "No ref ${GIT_BRANCH} found, falling back to develop" ; git checkout develop)
 
 : ${PORT_BASE:=8000}
+: ${PORT_COUNT=20}
 
 ./jenkins/prep_sytest_for_postgres.sh
 
@@ -81,6 +82,6 @@ echo >&2 "Running sytest with PostgreSQL";
                              --dendron $WORKSPACE/dendron/bin/dendron \
                              --pusher \
                              --synchrotron \
-                             --port-base $PORT_BASE
+                             --port-range ${PORT_BASE}:$((PORT_BASE+PORT_COUNT-1))
 
 cd ..
diff --git a/jenkins-postgres.sh b/jenkins-postgres.sh
index ae6b111591..2f0768fcb7 100755
--- a/jenkins-postgres.sh
+++ b/jenkins-postgres.sh
@@ -44,6 +44,7 @@ cd sytest
 git checkout "${GIT_BRANCH}" || (echo >&2 "No ref ${GIT_BRANCH} found, falling back to develop" ; git checkout develop)
 
 : ${PORT_BASE:=8000}
+: ${PORT_COUNT=20}
 
 ./jenkins/prep_sytest_for_postgres.sh
 
@@ -51,7 +52,7 @@ echo >&2 "Running sytest with PostgreSQL";
 ./jenkins/install_and_run.sh --coverage \
                              --python $TOX_BIN/python \
                              --synapse-directory $WORKSPACE \
-                             --port-base $PORT_BASE
+                             --port-range ${PORT_BASE}:$((PORT_BASE+PORT_COUNT-1)) \
 
 cd ..
 cp sytest/.coverage.* .
diff --git a/jenkins-sqlite.sh b/jenkins-sqlite.sh
index 9398d9db15..da603c5af8 100755
--- a/jenkins-sqlite.sh
+++ b/jenkins-sqlite.sh
@@ -41,11 +41,12 @@ cd sytest
 
 git checkout "${GIT_BRANCH}" || (echo >&2 "No ref ${GIT_BRANCH} found, falling back to develop" ; git checkout develop)
 
-: ${PORT_BASE:=8500}
+: ${PORT_COUNT=20}
+: ${PORT_BASE:=8000}
 ./jenkins/install_and_run.sh --coverage \
                              --python $TOX_BIN/python \
                              --synapse-directory $WORKSPACE \
-                             --port-base $PORT_BASE
+                             --port-range ${PORT_BASE}:$((PORT_BASE+PORT_COUNT-1)) \
 
 cd ..
 cp sytest/.coverage.* .
diff --git a/res/templates/notif_mail.html b/res/templates/notif_mail.html
index 8aee68b591..535bea764d 100644
--- a/res/templates/notif_mail.html
+++ b/res/templates/notif_mail.html
@@ -36,7 +36,7 @@
                         <div class="debug">
                             Sending email at {{ reason.now|format_ts("%c") }} due to activity in room {{ reason.room_name }} because
                             an event was received at {{ reason.received_at|format_ts("%c") }}
-                            which is more than {{ "%.1f"|format(reason.delay_before_mail_ms / (60*1000)) }} (delay_before_mail_ms) mins ago,
+                            which is more than {{ "%.1f"|format(reason.delay_before_mail_ms / (60*1000)) }} ({{ reason.delay_before_mail_ms }}) mins ago,
                             {% if reason.last_sent_ts %}
                                 and the last time we sent a mail for this room was {{ reason.last_sent_ts|format_ts("%c") }},
                                 which is more than {{ "%.1f"|format(reason.throttle_ms / (60*1000)) }} (current throttle_ms) mins ago.
diff --git a/scripts/hash_password b/scripts/hash_password
index e784600989..215ab25cfe 100755
--- a/scripts/hash_password
+++ b/scripts/hash_password
@@ -1,10 +1,16 @@
 #!/usr/bin/env python
 
 import argparse
+
+import sys
+
 import bcrypt
 import getpass
 
+import yaml
+
 bcrypt_rounds=12
+password_pepper = ""
 
 def prompt_for_pass():
     password = getpass.getpass("Password: ")
@@ -28,12 +34,22 @@ if __name__ == "__main__":
         default=None,
         help="New password for user. Will prompt if omitted.",
     )
+    parser.add_argument(
+        "-c", "--config",
+        type=argparse.FileType('r'),
+        help="Path to server config file. Used to read in bcrypt_rounds and password_pepper.",
+    )
 
     args = parser.parse_args()
+    if "config" in args and args.config:
+        config = yaml.safe_load(args.config)
+        bcrypt_rounds = config.get("bcrypt_rounds", bcrypt_rounds)
+        password_config = config.get("password_config", {})
+        password_pepper = password_config.get("pepper", password_pepper)
     password = args.password
 
     if not password:
         password = prompt_for_pass()
 
-    print bcrypt.hashpw(password, bcrypt.gensalt(bcrypt_rounds))
+    print bcrypt.hashpw(password + password_pepper, bcrypt.gensalt(bcrypt_rounds))
 
diff --git a/scripts/register_new_matrix_user b/scripts/register_new_matrix_user
index 27a6250b14..12ed20d623 100755
--- a/scripts/register_new_matrix_user
+++ b/scripts/register_new_matrix_user
@@ -25,18 +25,26 @@ import urllib2
 import yaml
 
 
-def request_registration(user, password, server_location, shared_secret):
+def request_registration(user, password, server_location, shared_secret, admin=False):
     mac = hmac.new(
         key=shared_secret,
-        msg=user,
         digestmod=hashlib.sha1,
-    ).hexdigest()
+    )
+
+    mac.update(user)
+    mac.update("\x00")
+    mac.update(password)
+    mac.update("\x00")
+    mac.update("admin" if admin else "notadmin")
+
+    mac = mac.hexdigest()
 
     data = {
         "user": user,
         "password": password,
         "mac": mac,
         "type": "org.matrix.login.shared_secret",
+        "admin": admin,
     }
 
     server_location = server_location.rstrip("/")
@@ -68,7 +76,7 @@ def request_registration(user, password, server_location, shared_secret):
         sys.exit(1)
 
 
-def register_new_user(user, password, server_location, shared_secret):
+def register_new_user(user, password, server_location, shared_secret, admin):
     if not user:
         try:
             default_user = getpass.getuser()
@@ -99,7 +107,14 @@ def register_new_user(user, password, server_location, shared_secret):
             print "Passwords do not match"
             sys.exit(1)
 
-    request_registration(user, password, server_location, shared_secret)
+    if not admin:
+        admin = raw_input("Make admin [no]: ")
+        if admin in ("y", "yes", "true"):
+            admin = True
+        else:
+            admin = False
+
+    request_registration(user, password, server_location, shared_secret, bool(admin))
 
 
 if __name__ == "__main__":
@@ -119,6 +134,11 @@ if __name__ == "__main__":
         default=None,
         help="New password for user. Will prompt if omitted.",
     )
+    parser.add_argument(
+        "-a", "--admin",
+        action="store_true",
+        help="Register new user as an admin. Will prompt if omitted.",
+    )
 
     group = parser.add_mutually_exclusive_group(required=True)
     group.add_argument(
@@ -151,4 +171,4 @@ if __name__ == "__main__":
     else:
         secret = args.shared_secret
 
-    register_new_user(args.user, args.password, args.server_url, secret)
+    register_new_user(args.user, args.password, args.server_url, secret, args.admin)
diff --git a/synapse/api/errors.py b/synapse/api/errors.py
index b106fbed6d..b219b46a4b 100644
--- a/synapse/api/errors.py
+++ b/synapse/api/errors.py
@@ -42,8 +42,9 @@ class Codes(object):
     TOO_LARGE = "M_TOO_LARGE"
     EXCLUSIVE = "M_EXCLUSIVE"
     THREEPID_AUTH_FAILED = "M_THREEPID_AUTH_FAILED"
-    THREEPID_IN_USE = "THREEPID_IN_USE"
+    THREEPID_IN_USE = "M_THREEPID_IN_USE"
     INVALID_USERNAME = "M_INVALID_USERNAME"
+    SERVER_NOT_TRUSTED = "M_SERVER_NOT_TRUSTED"
 
 
 class CodeMessageException(RuntimeError):
diff --git a/synapse/app/homeserver.py b/synapse/app/homeserver.py
index 40ffd9bf0d..9c2dd32953 100755
--- a/synapse/app/homeserver.py
+++ b/synapse/app/homeserver.py
@@ -147,7 +147,7 @@ class SynapseHomeServer(HomeServer):
                         MEDIA_PREFIX: media_repo,
                         LEGACY_MEDIA_PREFIX: media_repo,
                         CONTENT_REPO_PREFIX: ContentRepoResource(
-                            self, self.config.uploads_path, self.auth, self.content_addr
+                            self, self.config.uploads_path
                         ),
                     })
 
@@ -301,7 +301,6 @@ def setup(config_options):
         db_config=config.database_config,
         tls_server_context_factory=tls_server_context_factory,
         config=config,
-        content_addr=config.content_addr,
         version_string=version_string,
         database_engine=database_engine,
     )
diff --git a/synapse/config/ldap.py b/synapse/config/ldap.py
index 9c14593a99..d83c2230be 100644
--- a/synapse/config/ldap.py
+++ b/synapse/config/ldap.py
@@ -13,40 +13,88 @@
 # See the License for the specific language governing permissions and
 # limitations under the License.
 
-from ._base import Config
+from ._base import Config, ConfigError
+
+
+MISSING_LDAP3 = (
+    "Missing ldap3 library. This is required for LDAP Authentication."
+)
+
+
+class LDAPMode(object):
+    SIMPLE = "simple",
+    SEARCH = "search",
+
+    LIST = (SIMPLE, SEARCH)
 
 
 class LDAPConfig(Config):
     def read_config(self, config):
-        ldap_config = config.get("ldap_config", None)
-        if ldap_config:
-            self.ldap_enabled = ldap_config.get("enabled", False)
-            self.ldap_server = ldap_config["server"]
-            self.ldap_port = ldap_config["port"]
-            self.ldap_tls = ldap_config.get("tls", False)
-            self.ldap_search_base = ldap_config["search_base"]
-            self.ldap_search_property = ldap_config["search_property"]
-            self.ldap_email_property = ldap_config["email_property"]
-            self.ldap_full_name_property = ldap_config["full_name_property"]
-        else:
-            self.ldap_enabled = False
-            self.ldap_server = None
-            self.ldap_port = None
-            self.ldap_tls = False
-            self.ldap_search_base = None
-            self.ldap_search_property = None
-            self.ldap_email_property = None
-            self.ldap_full_name_property = None
+        ldap_config = config.get("ldap_config", {})
+
+        self.ldap_enabled = ldap_config.get("enabled", False)
+
+        if self.ldap_enabled:
+            # verify dependencies are available
+            try:
+                import ldap3
+                ldap3  # to stop unused lint
+            except ImportError:
+                raise ConfigError(MISSING_LDAP3)
+
+            self.ldap_mode = LDAPMode.SIMPLE
+
+            # verify config sanity
+            self.require_keys(ldap_config, [
+                "uri",
+                "base",
+                "attributes",
+            ])
+
+            self.ldap_uri = ldap_config["uri"]
+            self.ldap_start_tls = ldap_config.get("start_tls", False)
+            self.ldap_base = ldap_config["base"]
+            self.ldap_attributes = ldap_config["attributes"]
+
+            if "bind_dn" in ldap_config:
+                self.ldap_mode = LDAPMode.SEARCH
+                self.require_keys(ldap_config, [
+                    "bind_dn",
+                    "bind_password",
+                ])
+
+                self.ldap_bind_dn = ldap_config["bind_dn"]
+                self.ldap_bind_password = ldap_config["bind_password"]
+                self.ldap_filter = ldap_config.get("filter", None)
+
+            # verify attribute lookup
+            self.require_keys(ldap_config['attributes'], [
+                "uid",
+                "name",
+                "mail",
+            ])
+
+    def require_keys(self, config, required):
+        missing = [key for key in required if key not in config]
+        if missing:
+            raise ConfigError(
+                "LDAP enabled but missing required config values: {}".format(
+                    ", ".join(missing)
+                )
+            )
 
     def default_config(self, **kwargs):
         return """\
         # ldap_config:
         #   enabled: true
-        #   server: "ldap://localhost"
-        #   port: 389
-        #   tls: false
-        #   search_base: "ou=Users,dc=example,dc=com"
-        #   search_property: "cn"
-        #   email_property: "email"
-        #   full_name_property: "givenName"
+        #   uri: "ldap://ldap.example.com:389"
+        #   start_tls: true
+        #   base: "ou=users,dc=example,dc=com"
+        #   attributes:
+        #      uid: "cn"
+        #      mail: "email"
+        #      name: "givenName"
+        #   #bind_dn:
+        #   #bind_password:
+        #   #filter: "(objectClass=posixAccount)"
         """
diff --git a/synapse/config/password.py b/synapse/config/password.py
index dec801ef41..a4bd171399 100644
--- a/synapse/config/password.py
+++ b/synapse/config/password.py
@@ -23,10 +23,14 @@ class PasswordConfig(Config):
     def read_config(self, config):
         password_config = config.get("password_config", {})
         self.password_enabled = password_config.get("enabled", True)
+        self.password_pepper = password_config.get("pepper", "")
 
     def default_config(self, config_dir_path, server_name, **kwargs):
         return """
         # Enable password for login.
         password_config:
            enabled: true
+           # Uncomment and change to a secret random string for extra security.
+           # DO NOT CHANGE THIS AFTER INITIAL SETUP!
+           #pepper: ""
         """
diff --git a/synapse/config/server.py b/synapse/config/server.py
index 7840dc3ad6..51eaf423ce 100644
--- a/synapse/config/server.py
+++ b/synapse/config/server.py
@@ -107,26 +107,6 @@ class ServerConfig(Config):
                 ]
             })
 
-        # Attempt to guess the content_addr for the v0 content repostitory
-        content_addr = config.get("content_addr")
-        if not content_addr:
-            for listener in self.listeners:
-                if listener["type"] == "http" and not listener.get("tls", False):
-                    unsecure_port = listener["port"]
-                    break
-            else:
-                raise RuntimeError("Could not determine 'content_addr'")
-
-            host = self.server_name
-            if ':' not in host:
-                host = "%s:%d" % (host, unsecure_port)
-            else:
-                host = host.split(':')[0]
-                host = "%s:%d" % (host, unsecure_port)
-            content_addr = "http://%s" % (host,)
-
-        self.content_addr = content_addr
-
     def default_config(self, server_name, **kwargs):
         if ":" in server_name:
             bind_port = int(server_name.split(":")[1])
@@ -169,7 +149,6 @@ class ServerConfig(Config):
         # room directory.
         # secondary_directory_servers:
         #     - matrix.org
-        #     - vector.im
 
         # List of ports that Synapse should listen on, their purpose and their
         # configuration.
diff --git a/synapse/federation/federation_server.py b/synapse/federation/federation_server.py
index 2a589524a4..85f5e752fe 100644
--- a/synapse/federation/federation_server.py
+++ b/synapse/federation/federation_server.py
@@ -49,6 +49,7 @@ class FederationServer(FederationBase):
         super(FederationServer, self).__init__(hs)
 
         self._room_pdu_linearizer = Linearizer()
+        self._server_linearizer = Linearizer()
 
     def set_handler(self, handler):
         """Sets the handler that the replication layer will use to communicate
@@ -89,11 +90,14 @@ class FederationServer(FederationBase):
     @defer.inlineCallbacks
     @log_function
     def on_backfill_request(self, origin, room_id, versions, limit):
-        pdus = yield self.handler.on_backfill_request(
-            origin, room_id, versions, limit
-        )
+        with (yield self._server_linearizer.queue((origin, room_id))):
+            pdus = yield self.handler.on_backfill_request(
+                origin, room_id, versions, limit
+            )
+
+            res = self._transaction_from_pdus(pdus).get_dict()
 
-        defer.returnValue((200, self._transaction_from_pdus(pdus).get_dict()))
+        defer.returnValue((200, res))
 
     @defer.inlineCallbacks
     @log_function
@@ -184,27 +188,28 @@ class FederationServer(FederationBase):
     @defer.inlineCallbacks
     @log_function
     def on_context_state_request(self, origin, room_id, event_id):
-        if event_id:
-            pdus = yield self.handler.get_state_for_pdu(
-                origin, room_id, event_id,
-            )
-            auth_chain = yield self.store.get_auth_chain(
-                [pdu.event_id for pdu in pdus]
-            )
+        with (yield self._server_linearizer.queue((origin, room_id))):
+            if event_id:
+                pdus = yield self.handler.get_state_for_pdu(
+                    origin, room_id, event_id,
+                )
+                auth_chain = yield self.store.get_auth_chain(
+                    [pdu.event_id for pdu in pdus]
+                )
 
-            for event in auth_chain:
-                # We sign these again because there was a bug where we
-                # incorrectly signed things the first time round
-                if self.hs.is_mine_id(event.event_id):
-                    event.signatures.update(
-                        compute_event_signature(
-                            event,
-                            self.hs.hostname,
-                            self.hs.config.signing_key[0]
+                for event in auth_chain:
+                    # We sign these again because there was a bug where we
+                    # incorrectly signed things the first time round
+                    if self.hs.is_mine_id(event.event_id):
+                        event.signatures.update(
+                            compute_event_signature(
+                                event,
+                                self.hs.hostname,
+                                self.hs.config.signing_key[0]
+                            )
                         )
-                    )
-        else:
-            raise NotImplementedError("Specify an event")
+            else:
+                raise NotImplementedError("Specify an event")
 
         defer.returnValue((200, {
             "pdus": [pdu.get_pdu_json() for pdu in pdus],
@@ -283,14 +288,16 @@ class FederationServer(FederationBase):
 
     @defer.inlineCallbacks
     def on_event_auth(self, origin, room_id, event_id):
-        time_now = self._clock.time_msec()
-        auth_pdus = yield self.handler.on_event_auth(event_id)
-        defer.returnValue((200, {
-            "auth_chain": [a.get_pdu_json(time_now) for a in auth_pdus],
-        }))
+        with (yield self._server_linearizer.queue((origin, room_id))):
+            time_now = self._clock.time_msec()
+            auth_pdus = yield self.handler.on_event_auth(event_id)
+            res = {
+                "auth_chain": [a.get_pdu_json(time_now) for a in auth_pdus],
+            }
+        defer.returnValue((200, res))
 
     @defer.inlineCallbacks
-    def on_query_auth_request(self, origin, content, event_id):
+    def on_query_auth_request(self, origin, content, room_id, event_id):
         """
         Content is a dict with keys::
             auth_chain (list): A list of events that give the auth chain.
@@ -309,32 +316,33 @@ class FederationServer(FederationBase):
         Returns:
             Deferred: Results in `dict` with the same format as `content`
         """
-        auth_chain = [
-            self.event_from_pdu_json(e)
-            for e in content["auth_chain"]
-        ]
-
-        signed_auth = yield self._check_sigs_and_hash_and_fetch(
-            origin, auth_chain, outlier=True
-        )
+        with (yield self._server_linearizer.queue((origin, room_id))):
+            auth_chain = [
+                self.event_from_pdu_json(e)
+                for e in content["auth_chain"]
+            ]
+
+            signed_auth = yield self._check_sigs_and_hash_and_fetch(
+                origin, auth_chain, outlier=True
+            )
 
-        ret = yield self.handler.on_query_auth(
-            origin,
-            event_id,
-            signed_auth,
-            content.get("rejects", []),
-            content.get("missing", []),
-        )
+            ret = yield self.handler.on_query_auth(
+                origin,
+                event_id,
+                signed_auth,
+                content.get("rejects", []),
+                content.get("missing", []),
+            )
 
-        time_now = self._clock.time_msec()
-        send_content = {
-            "auth_chain": [
-                e.get_pdu_json(time_now)
-                for e in ret["auth_chain"]
-            ],
-            "rejects": ret.get("rejects", []),
-            "missing": ret.get("missing", []),
-        }
+            time_now = self._clock.time_msec()
+            send_content = {
+                "auth_chain": [
+                    e.get_pdu_json(time_now)
+                    for e in ret["auth_chain"]
+                ],
+                "rejects": ret.get("rejects", []),
+                "missing": ret.get("missing", []),
+            }
 
         defer.returnValue(
             (200, send_content)
@@ -386,21 +394,24 @@ class FederationServer(FederationBase):
     @log_function
     def on_get_missing_events(self, origin, room_id, earliest_events,
                               latest_events, limit, min_depth):
-        logger.info(
-            "on_get_missing_events: earliest_events: %r, latest_events: %r,"
-            " limit: %d, min_depth: %d",
-            earliest_events, latest_events, limit, min_depth
-        )
-        missing_events = yield self.handler.on_get_missing_events(
-            origin, room_id, earliest_events, latest_events, limit, min_depth
-        )
+        with (yield self._server_linearizer.queue((origin, room_id))):
+            logger.info(
+                "on_get_missing_events: earliest_events: %r, latest_events: %r,"
+                " limit: %d, min_depth: %d",
+                earliest_events, latest_events, limit, min_depth
+            )
+            missing_events = yield self.handler.on_get_missing_events(
+                origin, room_id, earliest_events, latest_events, limit, min_depth
+            )
 
-        if len(missing_events) < 5:
-            logger.info("Returning %d events: %r", len(missing_events), missing_events)
-        else:
-            logger.info("Returning %d events", len(missing_events))
+            if len(missing_events) < 5:
+                logger.info(
+                    "Returning %d events: %r", len(missing_events), missing_events
+                )
+            else:
+                logger.info("Returning %d events", len(missing_events))
 
-        time_now = self._clock.time_msec()
+            time_now = self._clock.time_msec()
 
         defer.returnValue({
             "events": [ev.get_pdu_json(time_now) for ev in missing_events],
diff --git a/synapse/federation/transport/server.py b/synapse/federation/transport/server.py
index 8a1965f45a..26fa88ae84 100644
--- a/synapse/federation/transport/server.py
+++ b/synapse/federation/transport/server.py
@@ -388,7 +388,7 @@ class FederationQueryAuthServlet(BaseFederationServlet):
     @defer.inlineCallbacks
     def on_POST(self, origin, content, query, context, event_id):
         new_content = yield self.handler.on_query_auth_request(
-            origin, content, event_id
+            origin, content, context, event_id
         )
 
         defer.returnValue((200, new_content))
diff --git a/synapse/handlers/auth.py b/synapse/handlers/auth.py
index b38f81e999..e259213a36 100644
--- a/synapse/handlers/auth.py
+++ b/synapse/handlers/auth.py
@@ -20,6 +20,7 @@ from synapse.api.constants import LoginType
 from synapse.types import UserID
 from synapse.api.errors import AuthError, LoginError, Codes, StoreError, SynapseError
 from synapse.util.async import run_on_reactor
+from synapse.config.ldap import LDAPMode
 
 from twisted.web.client import PartialDownloadError
 
@@ -28,6 +29,12 @@ import bcrypt
 import pymacaroons
 import simplejson
 
+try:
+    import ldap3
+except ImportError:
+    ldap3 = None
+    pass
+
 import synapse.util.stringutils as stringutils
 
 
@@ -50,17 +57,20 @@ class AuthHandler(BaseHandler):
         self.INVALID_TOKEN_HTTP_STATUS = 401
 
         self.ldap_enabled = hs.config.ldap_enabled
-        self.ldap_server = hs.config.ldap_server
-        self.ldap_port = hs.config.ldap_port
-        self.ldap_tls = hs.config.ldap_tls
-        self.ldap_search_base = hs.config.ldap_search_base
-        self.ldap_search_property = hs.config.ldap_search_property
-        self.ldap_email_property = hs.config.ldap_email_property
-        self.ldap_full_name_property = hs.config.ldap_full_name_property
-
-        if self.ldap_enabled is True:
-            import ldap
-            logger.info("Import ldap version: %s", ldap.__version__)
+        if self.ldap_enabled:
+            if not ldap3:
+                raise RuntimeError(
+                    'Missing ldap3 library. This is required for LDAP Authentication.'
+                )
+            self.ldap_mode = hs.config.ldap_mode
+            self.ldap_uri = hs.config.ldap_uri
+            self.ldap_start_tls = hs.config.ldap_start_tls
+            self.ldap_base = hs.config.ldap_base
+            self.ldap_filter = hs.config.ldap_filter
+            self.ldap_attributes = hs.config.ldap_attributes
+            if self.ldap_mode == LDAPMode.SEARCH:
+                self.ldap_bind_dn = hs.config.ldap_bind_dn
+                self.ldap_bind_password = hs.config.ldap_bind_password
 
         self.hs = hs  # FIXME better possibility to access registrationHandler later?
 
@@ -452,40 +462,167 @@ class AuthHandler(BaseHandler):
 
     @defer.inlineCallbacks
     def _check_ldap_password(self, user_id, password):
-        if not self.ldap_enabled:
-            logger.debug("LDAP not configured")
+        """ Attempt to authenticate a user against an LDAP Server
+            and register an account if none exists.
+
+            Returns:
+                True if authentication against LDAP was successful
+        """
+
+        if not ldap3 or not self.ldap_enabled:
             defer.returnValue(False)
 
-        import ldap
+        if self.ldap_mode not in LDAPMode.LIST:
+            raise RuntimeError(
+                'Invalid ldap mode specified: {mode}'.format(
+                    mode=self.ldap_mode
+                )
+            )
 
-        logger.info("Authenticating %s with LDAP" % user_id)
         try:
-            ldap_url = "%s:%s" % (self.ldap_server, self.ldap_port)
-            logger.debug("Connecting LDAP server at %s" % ldap_url)
-            l = ldap.initialize(ldap_url)
-            if self.ldap_tls:
-                logger.debug("Initiating TLS")
-                self._connection.start_tls_s()
+            server = ldap3.Server(self.ldap_uri)
+            logger.debug(
+                "Attempting ldap connection with %s",
+                self.ldap_uri
+            )
 
-            local_name = UserID.from_string(user_id).localpart
+            localpart = UserID.from_string(user_id).localpart
+            if self.ldap_mode == LDAPMode.SIMPLE:
+                # bind with the the local users ldap credentials
+                bind_dn = "{prop}={value},{base}".format(
+                    prop=self.ldap_attributes['uid'],
+                    value=localpart,
+                    base=self.ldap_base
+                )
+                conn = ldap3.Connection(server, bind_dn, password)
+                logger.debug(
+                    "Established ldap connection in simple mode: %s",
+                    conn
+                )
 
-            dn = "%s=%s, %s" % (
-                self.ldap_search_property,
-                local_name,
-                self.ldap_search_base)
-            logger.debug("DN for LDAP authentication: %s" % dn)
+                if self.ldap_start_tls:
+                    conn.start_tls()
+                    logger.debug(
+                        "Upgraded ldap connection in simple mode through StartTLS: %s",
+                        conn
+                    )
+
+                conn.bind()
+
+            elif self.ldap_mode == LDAPMode.SEARCH:
+                # connect with preconfigured credentials and search for local user
+                conn = ldap3.Connection(
+                    server,
+                    self.ldap_bind_dn,
+                    self.ldap_bind_password
+                )
+                logger.debug(
+                    "Established ldap connection in search mode: %s",
+                    conn
+                )
+
+                if self.ldap_start_tls:
+                    conn.start_tls()
+                    logger.debug(
+                        "Upgraded ldap connection in search mode through StartTLS: %s",
+                        conn
+                    )
 
-            l.simple_bind_s(dn.encode('utf-8'), password.encode('utf-8'))
+                conn.bind()
 
+                # find matching dn
+                query = "({prop}={value})".format(
+                    prop=self.ldap_attributes['uid'],
+                    value=localpart
+                )
+                if self.ldap_filter:
+                    query = "(&{query}{filter})".format(
+                        query=query,
+                        filter=self.ldap_filter
+                    )
+                logger.debug("ldap search filter: %s", query)
+                result = conn.search(self.ldap_base, query)
+
+                if result and len(conn.response) == 1:
+                    # found exactly one result
+                    user_dn = conn.response[0]['dn']
+                    logger.debug('ldap search found dn: %s', user_dn)
+
+                    # unbind and reconnect, rebind with found dn
+                    conn.unbind()
+                    conn = ldap3.Connection(
+                        server,
+                        user_dn,
+                        password,
+                        auto_bind=True
+                    )
+                else:
+                    # found 0 or > 1 results, abort!
+                    logger.warn(
+                        "ldap search returned unexpected (%d!=1) amount of results",
+                        len(conn.response)
+                    )
+                    defer.returnValue(False)
+
+            logger.info(
+                "User authenticated against ldap server: %s",
+                conn
+            )
+
+            # check for existing account, if none exists, create one
             if not (yield self.does_user_exist(user_id)):
-                handler = self.hs.get_handlers().registration_handler
-                user_id, access_token = (
-                    yield handler.register(localpart=local_name)
+                # query user metadata for account creation
+                query = "({prop}={value})".format(
+                    prop=self.ldap_attributes['uid'],
+                    value=localpart
+                )
+
+                if self.ldap_mode == LDAPMode.SEARCH and self.ldap_filter:
+                    query = "(&{filter}{user_filter})".format(
+                        filter=query,
+                        user_filter=self.ldap_filter
+                    )
+                logger.debug("ldap registration filter: %s", query)
+
+                result = conn.search(
+                    search_base=self.ldap_base,
+                    search_filter=query,
+                    attributes=[
+                        self.ldap_attributes['name'],
+                        self.ldap_attributes['mail']
+                    ]
                 )
 
+                if len(conn.response) == 1:
+                    attrs = conn.response[0]['attributes']
+                    mail = attrs[self.ldap_attributes['mail']][0]
+                    name = attrs[self.ldap_attributes['name']][0]
+
+                    # create account
+                    registration_handler = self.hs.get_handlers().registration_handler
+                    user_id, access_token = (
+                        yield registration_handler.register(localpart=localpart)
+                    )
+
+                    # TODO: bind email, set displayname with data from ldap directory
+
+                    logger.info(
+                        "ldap registration successful: %d: %s (%s, %)",
+                        user_id,
+                        localpart,
+                        name,
+                        mail
+                    )
+                else:
+                    logger.warn(
+                        "ldap registration failed: unexpected (%d!=1) amount of results",
+                        len(result)
+                    )
+                    defer.returnValue(False)
+
             defer.returnValue(True)
-        except ldap.LDAPError, e:
-            logger.warn("LDAP error: %s", e)
+        except ldap3.core.exceptions.LDAPException as e:
+            logger.warn("Error during ldap authentication: %s", e)
             defer.returnValue(False)
 
     @defer.inlineCallbacks
@@ -613,7 +750,8 @@ class AuthHandler(BaseHandler):
         Returns:
             Hashed password (str).
         """
-        return bcrypt.hashpw(password, bcrypt.gensalt(self.bcrypt_rounds))
+        return bcrypt.hashpw(password + self.hs.config.password_pepper,
+                             bcrypt.gensalt(self.bcrypt_rounds))
 
     def validate_hash(self, password, stored_hash):
         """Validates that self.hash(password) == stored_hash.
@@ -626,6 +764,7 @@ class AuthHandler(BaseHandler):
             Whether self.hash(password) == stored_hash (bool).
         """
         if stored_hash:
-            return bcrypt.hashpw(password, stored_hash.encode('utf-8')) == stored_hash
+            return bcrypt.hashpw(password + self.hs.config.password_pepper,
+                                 stored_hash.encode('utf-8')) == stored_hash
         else:
             return False
diff --git a/synapse/handlers/federation.py b/synapse/handlers/federation.py
index 6c0bc7eafa..351b218247 100644
--- a/synapse/handlers/federation.py
+++ b/synapse/handlers/federation.py
@@ -1413,7 +1413,7 @@ class FederationHandler(BaseHandler):
                 local_view = dict(auth_events)
                 remote_view = dict(auth_events)
                 remote_view.update({
-                    (d.type, d.state_key): d for d in different_events
+                    (d.type, d.state_key): d for d in different_events if d
                 })
 
                 new_state, prev_state = self.state_handler.resolve_events(
diff --git a/synapse/handlers/identity.py b/synapse/handlers/identity.py
index 656ce124f9..559e5d5a71 100644
--- a/synapse/handlers/identity.py
+++ b/synapse/handlers/identity.py
@@ -21,7 +21,7 @@ from synapse.api.errors import (
 )
 from ._base import BaseHandler
 from synapse.util.async import run_on_reactor
-from synapse.api.errors import SynapseError
+from synapse.api.errors import SynapseError, Codes
 
 import json
 import logging
@@ -41,6 +41,20 @@ class IdentityHandler(BaseHandler):
             hs.config.use_insecure_ssl_client_just_for_testing_do_not_use
         )
 
+    def _should_trust_id_server(self, id_server):
+        if id_server not in self.trusted_id_servers:
+            if self.trust_any_id_server_just_for_testing_do_not_use:
+                logger.warn(
+                    "Trusting untrustworthy ID server %r even though it isn't"
+                    " in the trusted id list for testing because"
+                    " 'use_insecure_ssl_client_just_for_testing_do_not_use'"
+                    " is set in the config",
+                    id_server,
+                )
+            else:
+                return False
+        return True
+
     @defer.inlineCallbacks
     def threepid_from_creds(self, creds):
         yield run_on_reactor()
@@ -59,19 +73,12 @@ class IdentityHandler(BaseHandler):
         else:
             raise SynapseError(400, "No client_secret in creds")
 
-        if id_server not in self.trusted_id_servers:
-            if self.trust_any_id_server_just_for_testing_do_not_use:
-                logger.warn(
-                    "Trusting untrustworthy ID server %r even though it isn't"
-                    " in the trusted id list for testing because"
-                    " 'use_insecure_ssl_client_just_for_testing_do_not_use'"
-                    " is set in the config",
-                    id_server,
-                )
-            else:
-                logger.warn('%s is not a trusted ID server: rejecting 3pid ' +
-                            'credentials', id_server)
-                defer.returnValue(None)
+        if not self._should_trust_id_server(id_server):
+            logger.warn(
+                '%s is not a trusted ID server: rejecting 3pid ' +
+                'credentials', id_server
+            )
+            defer.returnValue(None)
 
         data = {}
         try:
@@ -129,6 +136,12 @@ class IdentityHandler(BaseHandler):
     def requestEmailToken(self, id_server, email, client_secret, send_attempt, **kwargs):
         yield run_on_reactor()
 
+        if not self._should_trust_id_server(id_server):
+            raise SynapseError(
+                400, "Untrusted ID server '%s'" % id_server,
+                Codes.SERVER_NOT_TRUSTED
+            )
+
         params = {
             'email': email,
             'client_secret': client_secret,
diff --git a/synapse/handlers/message.py b/synapse/handlers/message.py
index 15caf1950a..ad2753c1b5 100644
--- a/synapse/handlers/message.py
+++ b/synapse/handlers/message.py
@@ -26,7 +26,7 @@ from synapse.types import (
     UserID, RoomAlias, RoomStreamToken, StreamToken, get_domain_from_id
 )
 from synapse.util import unwrapFirstError
-from synapse.util.async import concurrently_execute, run_on_reactor
+from synapse.util.async import concurrently_execute, run_on_reactor, ReadWriteLock
 from synapse.util.caches.snapshot_cache import SnapshotCache
 from synapse.util.logcontext import preserve_fn
 from synapse.visibility import filter_events_for_client
@@ -50,6 +50,20 @@ class MessageHandler(BaseHandler):
         self.validator = EventValidator()
         self.snapshot_cache = SnapshotCache()
 
+        self.pagination_lock = ReadWriteLock()
+
+    @defer.inlineCallbacks
+    def purge_history(self, room_id, event_id):
+        event = yield self.store.get_event(event_id)
+
+        if event.room_id != room_id:
+            raise SynapseError(400, "Event is for wrong room.")
+
+        depth = event.depth
+
+        with (yield self.pagination_lock.write(room_id)):
+            yield self.store.delete_old_state(room_id, depth)
+
     @defer.inlineCallbacks
     def get_messages(self, requester, room_id=None, pagin_config=None,
                      as_client_event=True):
@@ -85,42 +99,43 @@ class MessageHandler(BaseHandler):
 
         source_config = pagin_config.get_source_config("room")
 
-        membership, member_event_id = yield self._check_in_room_or_world_readable(
-            room_id, user_id
-        )
+        with (yield self.pagination_lock.read(room_id)):
+            membership, member_event_id = yield self._check_in_room_or_world_readable(
+                room_id, user_id
+            )
 
-        if source_config.direction == 'b':
-            # if we're going backwards, we might need to backfill. This
-            # requires that we have a topo token.
-            if room_token.topological:
-                max_topo = room_token.topological
-            else:
-                max_topo = yield self.store.get_max_topological_token_for_stream_and_room(
-                    room_id, room_token.stream
-                )
+            if source_config.direction == 'b':
+                # if we're going backwards, we might need to backfill. This
+                # requires that we have a topo token.
+                if room_token.topological:
+                    max_topo = room_token.topological
+                else:
+                    max_topo = yield self.store.get_max_topological_token(
+                        room_id, room_token.stream
+                    )
+
+                if membership == Membership.LEAVE:
+                    # If they have left the room then clamp the token to be before
+                    # they left the room, to save the effort of loading from the
+                    # database.
+                    leave_token = yield self.store.get_topological_token_for_event(
+                        member_event_id
+                    )
+                    leave_token = RoomStreamToken.parse(leave_token)
+                    if leave_token.topological < max_topo:
+                        source_config.from_key = str(leave_token)
 
-            if membership == Membership.LEAVE:
-                # If they have left the room then clamp the token to be before
-                # they left the room, to save the effort of loading from the
-                # database.
-                leave_token = yield self.store.get_topological_token_for_event(
-                    member_event_id
+                yield self.hs.get_handlers().federation_handler.maybe_backfill(
+                    room_id, max_topo
                 )
-                leave_token = RoomStreamToken.parse(leave_token)
-                if leave_token.topological < max_topo:
-                    source_config.from_key = str(leave_token)
 
-            yield self.hs.get_handlers().federation_handler.maybe_backfill(
-                room_id, max_topo
+            events, next_key = yield data_source.get_pagination_rows(
+                requester.user, source_config, room_id
             )
 
-        events, next_key = yield data_source.get_pagination_rows(
-            requester.user, source_config, room_id
-        )
-
-        next_token = pagin_config.from_token.copy_and_replace(
-            "room_key", next_key
-        )
+            next_token = pagin_config.from_token.copy_and_replace(
+                "room_key", next_key
+            )
 
         if not events:
             defer.returnValue({
diff --git a/synapse/handlers/register.py b/synapse/handlers/register.py
index 0b7517221d..8c3381df8a 100644
--- a/synapse/handlers/register.py
+++ b/synapse/handlers/register.py
@@ -90,7 +90,8 @@ class RegistrationHandler(BaseHandler):
         password=None,
         generate_token=True,
         guest_access_token=None,
-        make_guest=False
+        make_guest=False,
+        admin=False,
     ):
         """Registers a new client on the server.
 
@@ -141,6 +142,7 @@ class RegistrationHandler(BaseHandler):
                     # If the user was a guest then they already have a profile
                     None if was_guest else user.localpart
                 ),
+                admin=admin,
             )
         else:
             # autogen a sequential user ID
@@ -358,7 +360,8 @@ class RegistrationHandler(BaseHandler):
         defer.returnValue(data)
 
     @defer.inlineCallbacks
-    def get_or_create_user(self, localpart, displayname, duration_seconds):
+    def get_or_create_user(self, localpart, displayname, duration_seconds,
+                           password_hash=None):
         """Creates a new user if the user does not exist,
         else revokes all previous access tokens and generates a new one.
 
@@ -394,7 +397,7 @@ class RegistrationHandler(BaseHandler):
             yield self.store.register(
                 user_id=user_id,
                 token=token,
-                password_hash=None,
+                password_hash=password_hash,
                 create_profile_with_localpart=user.localpart,
             )
         else:
diff --git a/synapse/push/httppusher.py b/synapse/push/httppusher.py
index 3992804845..2acc6cc214 100644
--- a/synapse/push/httppusher.py
+++ b/synapse/push/httppusher.py
@@ -38,6 +38,7 @@ class HttpPusher(object):
         self.hs = hs
         self.store = self.hs.get_datastore()
         self.clock = self.hs.get_clock()
+        self.state_handler = self.hs.get_state_handler()
         self.user_id = pusherdict['user_name']
         self.app_id = pusherdict['app_id']
         self.app_display_name = pusherdict['app_display_name']
@@ -237,7 +238,9 @@ class HttpPusher(object):
 
     @defer.inlineCallbacks
     def _build_notification_dict(self, event, tweaks, badge):
-        ctx = yield push_tools.get_context_for_event(self.hs.get_datastore(), event)
+        ctx = yield push_tools.get_context_for_event(
+            self.state_handler, event, self.user_id
+        )
 
         d = {
             'notification': {
@@ -269,8 +272,8 @@ class HttpPusher(object):
         if 'content' in event:
             d['notification']['content'] = event.content
 
-        if len(ctx['aliases']):
-            d['notification']['room_alias'] = ctx['aliases'][0]
+        # We no longer send aliases separately, instead, we send the human
+        # readable name of the room, which may be an alias.
         if 'sender_display_name' in ctx and len(ctx['sender_display_name']) > 0:
             d['notification']['sender_display_name'] = ctx['sender_display_name']
         if 'name' in ctx and len(ctx['name']) > 0:
diff --git a/synapse/push/push_tools.py b/synapse/push/push_tools.py
index 89a3b5e90a..6f2d1ad57d 100644
--- a/synapse/push/push_tools.py
+++ b/synapse/push/push_tools.py
@@ -14,6 +14,9 @@
 # limitations under the License.
 
 from twisted.internet import defer
+from synapse.util.presentable_names import (
+    calculate_room_name, name_from_member_event
+)
 
 
 @defer.inlineCallbacks
@@ -45,24 +48,21 @@ def get_badge_count(store, user_id):
 
 
 @defer.inlineCallbacks
-def get_context_for_event(store, ev):
-    name_aliases = yield store.get_room_name_and_aliases(
-        ev.room_id
-    )
+def get_context_for_event(state_handler, ev, user_id):
+    ctx = {}
 
-    ctx = {'aliases': name_aliases[1]}
-    if name_aliases[0] is not None:
-        ctx['name'] = name_aliases[0]
+    room_state = yield state_handler.get_current_state(ev.room_id)
 
-    their_member_events_for_room = yield store.get_current_state(
-        room_id=ev.room_id,
-        event_type='m.room.member',
-        state_key=ev.user_id
+    # we no longer bother setting room_alias, and make room_name the
+    # human-readable name instead, be that m.room.namer, an alias or
+    # a list of people in the room
+    name = calculate_room_name(
+        room_state, user_id, fallback_to_single_member=False
     )
-    for mev in their_member_events_for_room:
-        if mev.content['membership'] == 'join' and 'displayname' in mev.content:
-            dn = mev.content['displayname']
-            if dn is not None:
-                ctx['sender_display_name'] = dn
+    if name:
+        ctx['name'] = name
+
+    sender_state_event = room_state[("m.room.member", ev.sender)]
+    ctx['sender_display_name'] = name_from_member_event(sender_state_event)
 
     defer.returnValue(ctx)
diff --git a/synapse/python_dependencies.py b/synapse/python_dependencies.py
index e0a7a19777..e024cec0a2 100644
--- a/synapse/python_dependencies.py
+++ b/synapse/python_dependencies.py
@@ -48,6 +48,9 @@ CONDITIONAL_REQUIREMENTS = {
         "Jinja2>=2.8": ["Jinja2>=2.8"],
         "bleach>=1.4.2": ["bleach>=1.4.2"],
     },
+    "ldap": {
+        "ldap3>=1.0": ["ldap3>=1.0"],
+    },
 }
 
 
diff --git a/synapse/replication/slave/storage/events.py b/synapse/replication/slave/storage/events.py
index 877c68508c..369d839464 100644
--- a/synapse/replication/slave/storage/events.py
+++ b/synapse/replication/slave/storage/events.py
@@ -18,7 +18,6 @@ from ._slaved_id_tracker import SlavedIdTracker
 from synapse.api.constants import EventTypes
 from synapse.events import FrozenEvent
 from synapse.storage import DataStore
-from synapse.storage.room import RoomStore
 from synapse.storage.roommember import RoomMemberStore
 from synapse.storage.event_federation import EventFederationStore
 from synapse.storage.event_push_actions import EventPushActionsStore
@@ -64,7 +63,6 @@ class SlavedEventStore(BaseSlavedStore):
 
     # Cached functions can't be accessed through a class instance so we need
     # to reach inside the __dict__ to extract them.
-    get_room_name_and_aliases = RoomStore.__dict__["get_room_name_and_aliases"]
     get_rooms_for_user = RoomMemberStore.__dict__["get_rooms_for_user"]
     get_users_in_room = RoomMemberStore.__dict__["get_users_in_room"]
     get_latest_event_ids_in_room = EventFederationStore.__dict__[
@@ -202,7 +200,6 @@ class SlavedEventStore(BaseSlavedStore):
             self.get_rooms_for_user.invalidate_all()
             self.get_users_in_room.invalidate((event.room_id,))
             # self.get_joined_hosts_for_room.invalidate((event.room_id,))
-            self.get_room_name_and_aliases.invalidate((event.room_id,))
 
         self._invalidate_get_event_cache(event.event_id)
 
@@ -246,9 +243,3 @@ class SlavedEventStore(BaseSlavedStore):
         self._get_current_state_for_key.invalidate((
             event.room_id, event.type, event.state_key
         ))
-
-        if event.type in [EventTypes.Name, EventTypes.Aliases]:
-            self.get_room_name_and_aliases.invalidate(
-                (event.room_id,)
-            )
-            pass
diff --git a/synapse/rest/client/v1/admin.py b/synapse/rest/client/v1/admin.py
index aa05b3f023..b0cb31a448 100644
--- a/synapse/rest/client/v1/admin.py
+++ b/synapse/rest/client/v1/admin.py
@@ -46,5 +46,82 @@ class WhoisRestServlet(ClientV1RestServlet):
         defer.returnValue((200, ret))
 
 
+class PurgeMediaCacheRestServlet(ClientV1RestServlet):
+    PATTERNS = client_path_patterns("/admin/purge_media_cache")
+
+    def __init__(self, hs):
+        self.media_repository = hs.get_media_repository()
+        super(PurgeMediaCacheRestServlet, self).__init__(hs)
+
+    @defer.inlineCallbacks
+    def on_POST(self, request):
+        requester = yield self.auth.get_user_by_req(request)
+        is_admin = yield self.auth.is_server_admin(requester.user)
+
+        if not is_admin:
+            raise AuthError(403, "You are not a server admin")
+
+        before_ts = request.args.get("before_ts", None)
+        if not before_ts:
+            raise SynapseError(400, "Missing 'before_ts' arg")
+
+        logger.info("before_ts: %r", before_ts[0])
+
+        try:
+            before_ts = int(before_ts[0])
+        except Exception:
+            raise SynapseError(400, "Invalid 'before_ts' arg")
+
+        ret = yield self.media_repository.delete_old_remote_media(before_ts)
+
+        defer.returnValue((200, ret))
+
+
+class PurgeHistoryRestServlet(ClientV1RestServlet):
+    PATTERNS = client_path_patterns(
+        "/admin/purge_history/(?P<room_id>[^/]*)/(?P<event_id>[^/]*)"
+    )
+
+    @defer.inlineCallbacks
+    def on_POST(self, request, room_id, event_id):
+        requester = yield self.auth.get_user_by_req(request)
+        is_admin = yield self.auth.is_server_admin(requester.user)
+
+        if not is_admin:
+            raise AuthError(403, "You are not a server admin")
+
+        yield self.handlers.message_handler.purge_history(room_id, event_id)
+
+        defer.returnValue((200, {}))
+
+
+class DeactivateAccountRestServlet(ClientV1RestServlet):
+    PATTERNS = client_path_patterns("/admin/deactivate/(?P<target_user_id>[^/]*)")
+
+    def __init__(self, hs):
+        self.store = hs.get_datastore()
+        super(DeactivateAccountRestServlet, self).__init__(hs)
+
+    @defer.inlineCallbacks
+    def on_POST(self, request, target_user_id):
+        UserID.from_string(target_user_id)
+        requester = yield self.auth.get_user_by_req(request)
+        is_admin = yield self.auth.is_server_admin(requester.user)
+
+        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)
+
+        defer.returnValue((200, {}))
+
+
 def register_servlets(hs, http_server):
     WhoisRestServlet(hs).register(http_server)
+    PurgeMediaCacheRestServlet(hs).register(http_server)
+    DeactivateAccountRestServlet(hs).register(http_server)
+    PurgeHistoryRestServlet(hs).register(http_server)
diff --git a/synapse/rest/client/v1/register.py b/synapse/rest/client/v1/register.py
index e3f4fbb0bb..ce7099b18f 100644
--- a/synapse/rest/client/v1/register.py
+++ b/synapse/rest/client/v1/register.py
@@ -324,6 +324,14 @@ class RegisterRestServlet(ClientV1RestServlet):
             raise SynapseError(400, "Shared secret registration is not enabled")
 
         user = register_json["user"].encode("utf-8")
+        password = register_json["password"].encode("utf-8")
+        admin = register_json.get("admin", None)
+
+        # Its important to check as we use null bytes as HMAC field separators
+        if "\x00" in user:
+            raise SynapseError(400, "Invalid user")
+        if "\x00" in password:
+            raise SynapseError(400, "Invalid password")
 
         # str() because otherwise hmac complains that 'unicode' does not
         # have the buffer interface
@@ -331,17 +339,21 @@ class RegisterRestServlet(ClientV1RestServlet):
 
         want_mac = hmac.new(
             key=self.hs.config.registration_shared_secret,
-            msg=user,
             digestmod=sha1,
-        ).hexdigest()
-
-        password = register_json["password"].encode("utf-8")
+        )
+        want_mac.update(user)
+        want_mac.update("\x00")
+        want_mac.update(password)
+        want_mac.update("\x00")
+        want_mac.update("admin" if admin else "notadmin")
+        want_mac = want_mac.hexdigest()
 
         if compare_digest(want_mac, got_mac):
             handler = self.handlers.registration_handler
             user_id, token = yield handler.register(
                 localpart=user,
                 password=password,
+                admin=bool(admin),
             )
             self._remove_session(session)
             defer.returnValue({
@@ -410,12 +422,15 @@ class CreateUserRestServlet(ClientV1RestServlet):
             raise SynapseError(400, "Failed to parse 'duration_seconds'")
         if duration_seconds > self.direct_user_creation_max_duration:
             duration_seconds = self.direct_user_creation_max_duration
+        password_hash = user_json["password_hash"].encode("utf-8") \
+            if user_json.get("password_hash") else None
 
         handler = self.handlers.registration_handler
         user_id, token = yield handler.get_or_create_user(
             localpart=localpart,
             displayname=displayname,
-            duration_seconds=duration_seconds
+            duration_seconds=duration_seconds,
+            password_hash=password_hash
         )
 
         defer.returnValue({
diff --git a/synapse/rest/media/v0/content_repository.py b/synapse/rest/media/v0/content_repository.py
index d9fc045fc6..956bd5da75 100644
--- a/synapse/rest/media/v0/content_repository.py
+++ b/synapse/rest/media/v0/content_repository.py
@@ -15,14 +15,12 @@
 
 from synapse.http.server import respond_with_json_bytes, finish_request
 
-from synapse.util.stringutils import random_string
 from synapse.api.errors import (
-    cs_exception, SynapseError, CodeMessageException, Codes, cs_error
+    Codes, cs_error
 )
 
 from twisted.protocols.basic import FileSender
 from twisted.web import server, resource
-from twisted.internet import defer
 
 import base64
 import simplejson as json
@@ -50,64 +48,10 @@ class ContentRepoResource(resource.Resource):
     """
     isLeaf = True
 
-    def __init__(self, hs, directory, auth, external_addr):
+    def __init__(self, hs, directory):
         resource.Resource.__init__(self)
         self.hs = hs
         self.directory = directory
-        self.auth = auth
-        self.external_addr = external_addr.rstrip('/')
-        self.max_upload_size = hs.config.max_upload_size
-
-        if not os.path.isdir(self.directory):
-            os.mkdir(self.directory)
-            logger.info("ContentRepoResource : Created %s directory.",
-                        self.directory)
-
-    @defer.inlineCallbacks
-    def map_request_to_name(self, request):
-        # auth the user
-        requester = yield self.auth.get_user_by_req(request)
-
-        # namespace all file uploads on the user
-        prefix = base64.urlsafe_b64encode(
-            requester.user.to_string()
-        ).replace('=', '')
-
-        # use a random string for the main portion
-        main_part = random_string(24)
-
-        # suffix with a file extension if we can make one. This is nice to
-        # provide a hint to clients on the file information. We will also reuse
-        # this info to spit back the content type to the client.
-        suffix = ""
-        if request.requestHeaders.hasHeader("Content-Type"):
-            content_type = request.requestHeaders.getRawHeaders(
-                "Content-Type")[0]
-            suffix = "." + base64.urlsafe_b64encode(content_type)
-            if (content_type.split("/")[0].lower() in
-                    ["image", "video", "audio"]):
-                file_ext = content_type.split("/")[-1]
-                # be a little paranoid and only allow a-z
-                file_ext = re.sub("[^a-z]", "", file_ext)
-                suffix += "." + file_ext
-
-        file_name = prefix + main_part + suffix
-        file_path = os.path.join(self.directory, file_name)
-        logger.info("User %s is uploading a file to path %s",
-                    request.user.user_id.to_string(),
-                    file_path)
-
-        # keep trying to make a non-clashing file, with a sensible max attempts
-        attempts = 0
-        while os.path.exists(file_path):
-            main_part = random_string(24)
-            file_name = prefix + main_part + suffix
-            file_path = os.path.join(self.directory, file_name)
-            attempts += 1
-            if attempts > 25:  # really? Really?
-                raise SynapseError(500, "Unable to create file.")
-
-        defer.returnValue(file_path)
 
     def render_GET(self, request):
         # no auth here on purpose, to allow anyone to view, even across home
@@ -155,58 +99,6 @@ class ContentRepoResource(resource.Resource):
 
         return server.NOT_DONE_YET
 
-    def render_POST(self, request):
-        self._async_render(request)
-        return server.NOT_DONE_YET
-
     def render_OPTIONS(self, request):
         respond_with_json_bytes(request, 200, {}, send_cors=True)
         return server.NOT_DONE_YET
-
-    @defer.inlineCallbacks
-    def _async_render(self, request):
-        try:
-            # TODO: The checks here are a bit late. The content will have
-            # already been uploaded to a tmp file at this point
-            content_length = request.getHeader("Content-Length")
-            if content_length is None:
-                raise SynapseError(
-                    msg="Request must specify a Content-Length", code=400
-                )
-            if int(content_length) > self.max_upload_size:
-                raise SynapseError(
-                    msg="Upload request body is too large",
-                    code=413,
-                )
-
-            fname = yield self.map_request_to_name(request)
-
-            # TODO I have a suspicious feeling this is just going to block
-            with open(fname, "wb") as f:
-                f.write(request.content.read())
-
-            # FIXME (erikj): These should use constants.
-            file_name = os.path.basename(fname)
-            # FIXME: we can't assume what the repo's public mounted path is
-            # ...plus self-signed SSL won't work to remote clients anyway
-            # ...and we can't assume that it's SSL anyway, as we might want to
-            # serve it via the non-SSL listener...
-            url = "%s/_matrix/content/%s" % (
-                self.external_addr, file_name
-            )
-
-            respond_with_json_bytes(request, 200,
-                                    json.dumps({"content_token": url}),
-                                    send_cors=True)
-
-        except CodeMessageException as e:
-            logger.exception(e)
-            respond_with_json_bytes(request, e.code,
-                                    json.dumps(cs_exception(e)))
-        except Exception as e:
-            logger.error("Failed to store file: %s" % e)
-            respond_with_json_bytes(
-                request,
-                500,
-                json.dumps({"error": "Internal server error"}),
-                send_cors=True)
diff --git a/synapse/rest/media/v1/filepath.py b/synapse/rest/media/v1/filepath.py
index 422ab86fb3..0137458f71 100644
--- a/synapse/rest/media/v1/filepath.py
+++ b/synapse/rest/media/v1/filepath.py
@@ -65,3 +65,9 @@ class MediaFilePaths(object):
             file_id[0:2], file_id[2:4], file_id[4:],
             file_name
         )
+
+    def remote_media_thumbnail_dir(self, server_name, file_id):
+        return os.path.join(
+            self.base_path, "remote_thumbnail", server_name,
+            file_id[0:2], file_id[2:4], file_id[4:],
+        )
diff --git a/synapse/rest/media/v1/media_repository.py b/synapse/rest/media/v1/media_repository.py
index 2468c3ac42..692e078419 100644
--- a/synapse/rest/media/v1/media_repository.py
+++ b/synapse/rest/media/v1/media_repository.py
@@ -30,11 +30,13 @@ from synapse.api.errors import SynapseError
 
 from twisted.internet import defer, threads
 
-from synapse.util.async import ObservableDeferred
+from synapse.util.async import Linearizer
 from synapse.util.stringutils import is_ascii
 from synapse.util.logcontext import preserve_context_over_fn
 
 import os
+import errno
+import shutil
 
 import cgi
 import logging
@@ -43,8 +45,11 @@ import urlparse
 logger = logging.getLogger(__name__)
 
 
+UPDATE_RECENTLY_ACCESSED_REMOTES_TS = 60 * 1000
+
+
 class MediaRepository(object):
-    def __init__(self, hs, filepaths):
+    def __init__(self, hs):
         self.auth = hs.get_auth()
         self.client = MatrixFederationHttpClient(hs)
         self.clock = hs.get_clock()
@@ -52,11 +57,28 @@ class MediaRepository(object):
         self.store = hs.get_datastore()
         self.max_upload_size = hs.config.max_upload_size
         self.max_image_pixels = hs.config.max_image_pixels
-        self.filepaths = filepaths
-        self.downloads = {}
+        self.filepaths = MediaFilePaths(hs.config.media_store_path)
         self.dynamic_thumbnails = hs.config.dynamic_thumbnails
         self.thumbnail_requirements = hs.config.thumbnail_requirements
 
+        self.remote_media_linearizer = Linearizer()
+
+        self.recently_accessed_remotes = set()
+
+        self.clock.looping_call(
+            self._update_recently_accessed_remotes,
+            UPDATE_RECENTLY_ACCESSED_REMOTES_TS
+        )
+
+    @defer.inlineCallbacks
+    def _update_recently_accessed_remotes(self):
+        media = self.recently_accessed_remotes
+        self.recently_accessed_remotes = set()
+
+        yield self.store.update_cached_last_access_time(
+            media, self.clock.time_msec()
+        )
+
     @staticmethod
     def _makedirs(filepath):
         dirname = os.path.dirname(filepath)
@@ -93,22 +115,12 @@ class MediaRepository(object):
 
         defer.returnValue("mxc://%s/%s" % (self.server_name, media_id))
 
+    @defer.inlineCallbacks
     def get_remote_media(self, server_name, media_id):
         key = (server_name, media_id)
-        download = self.downloads.get(key)
-        if download is None:
-            download = self._get_remote_media_impl(server_name, media_id)
-            download = ObservableDeferred(
-                download,
-                consumeErrors=True
-            )
-            self.downloads[key] = download
-
-            @download.addBoth
-            def callback(media_info):
-                del self.downloads[key]
-                return media_info
-        return download.observe()
+        with (yield self.remote_media_linearizer.queue(key)):
+            media_info = yield self._get_remote_media_impl(server_name, media_id)
+        defer.returnValue(media_info)
 
     @defer.inlineCallbacks
     def _get_remote_media_impl(self, server_name, media_id):
@@ -119,6 +131,11 @@ class MediaRepository(object):
             media_info = yield self._download_remote_file(
                 server_name, media_id
             )
+        else:
+            self.recently_accessed_remotes.add((server_name, media_id))
+            yield self.store.update_cached_last_access_time(
+                [(server_name, media_id)], self.clock.time_msec()
+            )
         defer.returnValue(media_info)
 
     @defer.inlineCallbacks
@@ -416,6 +433,41 @@ class MediaRepository(object):
             "height": m_height,
         })
 
+    @defer.inlineCallbacks
+    def delete_old_remote_media(self, before_ts):
+        old_media = yield self.store.get_remote_media_before(before_ts)
+
+        deleted = 0
+
+        for media in old_media:
+            origin = media["media_origin"]
+            media_id = media["media_id"]
+            file_id = media["filesystem_id"]
+            key = (origin, media_id)
+
+            logger.info("Deleting: %r", key)
+
+            with (yield self.remote_media_linearizer.queue(key)):
+                full_path = self.filepaths.remote_media_filepath(origin, file_id)
+                try:
+                    os.remove(full_path)
+                except OSError as e:
+                    logger.warn("Failed to remove file: %r", full_path)
+                    if e.errno == errno.ENOENT:
+                        pass
+                    else:
+                        continue
+
+                thumbnail_dir = self.filepaths.remote_media_thumbnail_dir(
+                    origin, file_id
+                )
+                shutil.rmtree(thumbnail_dir, ignore_errors=True)
+
+                yield self.store.delete_remote_media(origin, media_id)
+                deleted += 1
+
+        defer.returnValue({"deleted": deleted})
+
 
 class MediaRepositoryResource(Resource):
     """File uploading and downloading.
@@ -464,9 +516,8 @@ class MediaRepositoryResource(Resource):
 
     def __init__(self, hs):
         Resource.__init__(self)
-        filepaths = MediaFilePaths(hs.config.media_store_path)
 
-        media_repo = MediaRepository(hs, filepaths)
+        media_repo = hs.get_media_repository()
 
         self.putChild("upload", UploadResource(hs, media_repo))
         self.putChild("download", DownloadResource(hs, media_repo))
diff --git a/synapse/server.py b/synapse/server.py
index dd4b81c658..d49a1a8a96 100644
--- a/synapse/server.py
+++ b/synapse/server.py
@@ -45,6 +45,7 @@ from synapse.crypto.keyring import Keyring
 from synapse.push.pusherpool import PusherPool
 from synapse.events.builder import EventBuilderFactory
 from synapse.api.filtering import Filtering
+from synapse.rest.media.v1.media_repository import MediaRepository
 
 from synapse.http.matrixfederationclient import MatrixFederationHttpClient
 
@@ -113,6 +114,7 @@ class HomeServer(object):
         'filtering',
         'http_client_context_factory',
         'simple_http_client',
+        'media_repository',
     ]
 
     def __init__(self, hostname, **kwargs):
@@ -233,6 +235,9 @@ class HomeServer(object):
             **self.db_config.get("args", {})
         )
 
+    def build_media_repository(self):
+        return MediaRepository(self)
+
     def remove_pusher(self, app_id, push_key, user_id):
         return self.get_pusherpool().remove_pusher(app_id, push_key, user_id)
 
diff --git a/synapse/storage/_base.py b/synapse/storage/_base.py
index 32c6677d47..d766a30299 100644
--- a/synapse/storage/_base.py
+++ b/synapse/storage/_base.py
@@ -807,6 +807,11 @@ class SQLBaseStore(object):
         if txn.rowcount > 1:
             raise StoreError(500, "more than one row matched")
 
+    def _simple_delete(self, table, keyvalues, desc):
+        return self.runInteraction(
+            desc, self._simple_delete_txn, table, keyvalues
+        )
+
     @staticmethod
     def _simple_delete_txn(txn, table, keyvalues):
         sql = "DELETE FROM %s WHERE %s" % (
diff --git a/synapse/storage/event_push_actions.py b/synapse/storage/event_push_actions.py
index 940e11d7a2..3d93285f84 100644
--- a/synapse/storage/event_push_actions.py
+++ b/synapse/storage/event_push_actions.py
@@ -16,6 +16,8 @@
 from ._base import SQLBaseStore
 from twisted.internet import defer
 from synapse.util.caches.descriptors import cachedInlineCallbacks
+from synapse.types import RoomStreamToken
+from .stream import lower_bound
 
 import logging
 import ujson as json
@@ -73,6 +75,9 @@ class EventPushActionsStore(SQLBaseStore):
 
             stream_ordering = results[0][0]
             topological_ordering = results[0][1]
+            token = RoomStreamToken(
+                topological_ordering, stream_ordering
+            )
 
             sql = (
                 "SELECT sum(notif), sum(highlight)"
@@ -80,15 +85,10 @@ class EventPushActionsStore(SQLBaseStore):
                 " WHERE"
                 " user_id = ?"
                 " AND room_id = ?"
-                " AND ("
-                "       topological_ordering > ?"
-                "       OR (topological_ordering = ? AND stream_ordering > ?)"
-                ")"
-            )
-            txn.execute(sql, (
-                user_id, room_id,
-                topological_ordering, topological_ordering, stream_ordering
-            ))
+                " AND %s"
+            ) % (lower_bound(token, self.database_engine, inclusive=False),)
+
+            txn.execute(sql, (user_id, room_id))
             row = txn.fetchone()
             if row:
                 return {
@@ -152,7 +152,7 @@ class EventPushActionsStore(SQLBaseStore):
             if max_stream_ordering is not None:
                 sql += " AND ep.stream_ordering <= ?"
                 args.append(max_stream_ordering)
-            sql += " ORDER BY ep.stream_ordering ASC LIMIT ?"
+            sql += " ORDER BY ep.stream_ordering DESC LIMIT ?"
             args.append(limit)
             txn.execute(sql, args)
             return txn.fetchall()
@@ -176,14 +176,16 @@ class EventPushActionsStore(SQLBaseStore):
             if max_stream_ordering is not None:
                 sql += " AND ep.stream_ordering <= ?"
                 args.append(max_stream_ordering)
-            sql += " ORDER BY ep.stream_ordering ASC"
+            sql += " ORDER BY ep.stream_ordering DESC LIMIT ?"
+            args.append(limit)
             txn.execute(sql, args)
             return txn.fetchall()
         no_read_receipt = yield self.runInteraction(
             "get_unread_push_actions_for_user_in_range", get_no_receipt
         )
 
-        defer.returnValue([
+        # Make a list of dicts from the two sets of results.
+        notifs = [
             {
                 "event_id": row[0],
                 "room_id": row[1],
@@ -191,7 +193,16 @@ class EventPushActionsStore(SQLBaseStore):
                 "actions": json.loads(row[3]),
                 "received_ts": row[4],
             } for row in after_read_receipt + no_read_receipt
-        ])
+        ]
+
+        # Now sort it so it's ordered correctly, since currently it will
+        # contain results from the first query, correctly ordered, followed
+        # by results from the second query, but we want them all ordered
+        # by received_ts
+        notifs.sort(key=lambda r: -(r['received_ts'] or 0))
+
+        # Now return the first `limit`
+        defer.returnValue(notifs[:limit])
 
     @defer.inlineCallbacks
     def get_time_of_last_push_action_before(self, stream_ordering):
diff --git a/synapse/storage/events.py b/synapse/storage/events.py
index 6d978ffcd5..b582942164 100644
--- a/synapse/storage/events.py
+++ b/synapse/storage/events.py
@@ -23,6 +23,7 @@ from synapse.util.async import ObservableDeferred
 from synapse.util.logcontext import preserve_fn, PreserveLoggingContext
 from synapse.util.logutils import log_function
 from synapse.api.constants import EventTypes
+from synapse.api.errors import SynapseError
 
 from canonicaljson import encode_canonical_json
 from collections import deque, namedtuple
@@ -355,7 +356,6 @@ class EventsStore(SQLBaseStore):
             txn.call_after(self.get_rooms_for_user.invalidate_all)
             txn.call_after(self.get_users_in_room.invalidate, (event.room_id,))
             txn.call_after(self.get_joined_hosts_for_room.invalidate, (event.room_id,))
-            txn.call_after(self.get_room_name_and_aliases.invalidate, (event.room_id,))
 
             # Add an entry to the current_state_resets table to record the point
             # where we clobbered the current state
@@ -666,12 +666,6 @@ class EventsStore(SQLBaseStore):
                 (event.room_id, event.type, event.state_key,)
             )
 
-            if event.type in [EventTypes.Name, EventTypes.Aliases]:
-                txn.call_after(
-                    self.get_room_name_and_aliases.invalidate,
-                    (event.room_id,)
-                )
-
             self._simple_upsert_txn(
                 txn,
                 "current_state_events",
@@ -1288,6 +1282,156 @@ class EventsStore(SQLBaseStore):
             )
         return self.runInteraction("get_all_new_events", get_all_new_events_txn)
 
+    def delete_old_state(self, room_id, topological_ordering):
+        return self.runInteraction(
+            "delete_old_state",
+            self._delete_old_state_txn, room_id, topological_ordering
+        )
+
+    def _delete_old_state_txn(self, txn, room_id, topological_ordering):
+        """Deletes old room state
+        """
+
+        # Tables that should be pruned:
+        #     event_auth
+        #     event_backward_extremities
+        #     event_content_hashes
+        #     event_destinations
+        #     event_edge_hashes
+        #     event_edges
+        #     event_forward_extremities
+        #     event_json
+        #     event_push_actions
+        #     event_reference_hashes
+        #     event_search
+        #     event_signatures
+        #     event_to_state_groups
+        #     events
+        #     rejections
+        #     room_depth
+        #     state_groups
+        #     state_groups_state
+
+        # First ensure that we're not about to delete all the forward extremeties
+        txn.execute(
+            "SELECT e.event_id, e.depth FROM events as e "
+            "INNER JOIN event_forward_extremities as f "
+            "ON e.event_id = f.event_id "
+            "AND e.room_id = f.room_id "
+            "WHERE f.room_id = ?",
+            (room_id,)
+        )
+        rows = txn.fetchall()
+        max_depth = max(row[0] for row in rows)
+
+        if max_depth <= topological_ordering:
+            # We need to ensure we don't delete all the events from the datanase
+            # otherwise we wouldn't be able to send any events (due to not
+            # having any backwards extremeties)
+            raise SynapseError(
+                400, "topological_ordering is greater than forward extremeties"
+            )
+
+        txn.execute(
+            "SELECT event_id, state_key FROM events"
+            " LEFT JOIN state_events USING (room_id, event_id)"
+            " WHERE room_id = ? AND topological_ordering < ?",
+            (room_id, topological_ordering,)
+        )
+        event_rows = txn.fetchall()
+
+        # We calculate the new entries for the backward extremeties by finding
+        # all events that point to events that are to be purged
+        txn.execute(
+            "SELECT e.event_id FROM events as e"
+            " INNER JOIN event_edges as ed ON e.event_id = ed.prev_event_id"
+            " INNER JOIN events as e2 ON e2.event_id = ed.event_id"
+            " WHERE e.room_id = ? AND e.topological_ordering < ?"
+            " AND e2.topological_ordering >= ?",
+            (room_id, topological_ordering, topological_ordering)
+        )
+        new_backwards_extrems = txn.fetchall()
+
+        # Get all state groups that are only referenced by events that are
+        # to be deleted.
+        txn.execute(
+            "SELECT state_group FROM event_to_state_groups"
+            " INNER JOIN events USING (event_id)"
+            " WHERE state_group IN ("
+            "   SELECT DISTINCT state_group FROM events"
+            "   INNER JOIN event_to_state_groups USING (event_id)"
+            "   WHERE room_id = ? AND topological_ordering < ?"
+            " )"
+            " GROUP BY state_group HAVING MAX(topological_ordering) < ?",
+            (room_id, topological_ordering, topological_ordering)
+        )
+        state_rows = txn.fetchall()
+        txn.executemany(
+            "DELETE FROM state_groups_state WHERE state_group = ?",
+            state_rows
+        )
+        txn.executemany(
+            "DELETE FROM state_groups WHERE id = ?",
+            state_rows
+        )
+        # Delete all non-state
+        txn.executemany(
+            "DELETE FROM event_to_state_groups WHERE event_id = ?",
+            [(event_id,) for event_id, _ in event_rows]
+        )
+
+        txn.execute(
+            "UPDATE room_depth SET min_depth = ? WHERE room_id = ?",
+            (topological_ordering, room_id,)
+        )
+
+        # Delete all remote non-state events
+        to_delete = [
+            (event_id,) for event_id, state_key in event_rows
+            if state_key is None and not self.hs.is_mine_id(event_id)
+        ]
+        for table in (
+            "events",
+            "event_json",
+            "event_auth",
+            "event_content_hashes",
+            "event_destinations",
+            "event_edge_hashes",
+            "event_edges",
+            "event_forward_extremities",
+            "event_push_actions",
+            "event_reference_hashes",
+            "event_search",
+            "event_signatures",
+            "rejections",
+            "event_backward_extremities",
+        ):
+            txn.executemany(
+                "DELETE FROM %s WHERE event_id = ?" % (table,),
+                to_delete
+            )
+
+        # Update backward extremeties
+        txn.executemany(
+            "INSERT INTO event_backward_extremities (room_id, event_id)"
+            " VALUES (?, ?)",
+            [(room_id, event_id) for event_id, in new_backwards_extrems]
+        )
+
+        txn.executemany(
+            "DELETE FROM events WHERE event_id = ?",
+            to_delete
+        )
+        # Mark all state and own events as outliers
+        txn.executemany(
+            "UPDATE events SET outlier = ?"
+            " WHERE event_id = ?",
+            [
+                (True, event_id,) for event_id, state_key in event_rows
+                if state_key is not None or self.hs.is_mine_id(event_id)
+            ]
+        )
+
 
 AllNewEventsResult = namedtuple("AllNewEventsResult", [
     "new_forward_events", "new_backfill_events",
diff --git a/synapse/storage/media_repository.py b/synapse/storage/media_repository.py
index a820fcf07f..4c0f82353d 100644
--- a/synapse/storage/media_repository.py
+++ b/synapse/storage/media_repository.py
@@ -157,10 +157,25 @@ class MediaRepositoryStore(SQLBaseStore):
                 "created_ts": time_now_ms,
                 "upload_name": upload_name,
                 "filesystem_id": filesystem_id,
+                "last_access_ts": time_now_ms,
             },
             desc="store_cached_remote_media",
         )
 
+    def update_cached_last_access_time(self, origin_id_tuples, time_ts):
+        def update_cache_txn(txn):
+            sql = (
+                "UPDATE remote_media_cache SET last_access_ts = ?"
+                " WHERE media_origin = ? AND media_id = ?"
+            )
+
+            txn.executemany(sql, (
+                (time_ts, media_origin, media_id)
+                for media_origin, media_id in origin_id_tuples
+            ))
+
+        return self.runInteraction("update_cached_last_access_time", update_cache_txn)
+
     def get_remote_media_thumbnails(self, origin, media_id):
         return self._simple_select_list(
             "remote_media_cache_thumbnails",
@@ -190,3 +205,32 @@ class MediaRepositoryStore(SQLBaseStore):
             },
             desc="store_remote_media_thumbnail",
         )
+
+    def get_remote_media_before(self, before_ts):
+        sql = (
+            "SELECT media_origin, media_id, filesystem_id"
+            " FROM remote_media_cache"
+            " WHERE last_access_ts < ?"
+        )
+
+        return self._execute(
+            "get_remote_media_before", self.cursor_to_dict, sql, before_ts
+        )
+
+    def delete_remote_media(self, media_origin, media_id):
+        def delete_remote_media_txn(txn):
+            self._simple_delete_txn(
+                txn,
+                "remote_media_cache",
+                keyvalues={
+                    "media_origin": media_origin, "media_id": media_id
+                },
+            )
+            self._simple_delete_txn(
+                txn,
+                "remote_media_cache_thumbnails",
+                keyvalues={
+                    "media_origin": media_origin, "media_id": media_id
+                },
+            )
+        return self.runInteraction("delete_remote_media", delete_remote_media_txn)
diff --git a/synapse/storage/prepare_database.py b/synapse/storage/prepare_database.py
index c8487c8838..8801669a6b 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 = 32
+SCHEMA_VERSION = 33
 
 dir_path = os.path.abspath(os.path.dirname(__file__))
 
diff --git a/synapse/storage/registration.py b/synapse/storage/registration.py
index 3de9e0f709..0a68341494 100644
--- a/synapse/storage/registration.py
+++ b/synapse/storage/registration.py
@@ -77,7 +77,7 @@ class RegistrationStore(SQLBaseStore):
     @defer.inlineCallbacks
     def register(self, user_id, token, password_hash,
                  was_guest=False, make_guest=False, appservice_id=None,
-                 create_profile_with_localpart=None):
+                 create_profile_with_localpart=None, admin=False):
         """Attempts to register an account.
 
         Args:
@@ -104,6 +104,7 @@ class RegistrationStore(SQLBaseStore):
             make_guest,
             appservice_id,
             create_profile_with_localpart,
+            admin
         )
         self.get_user_by_id.invalidate((user_id,))
         self.is_guest.invalidate((user_id,))
@@ -118,6 +119,7 @@ class RegistrationStore(SQLBaseStore):
         make_guest,
         appservice_id,
         create_profile_with_localpart,
+        admin,
     ):
         now = int(self.clock.time())
 
@@ -125,29 +127,33 @@ class RegistrationStore(SQLBaseStore):
 
         try:
             if was_guest:
-                txn.execute("UPDATE users SET"
-                            " password_hash = ?,"
-                            " upgrade_ts = ?,"
-                            " is_guest = ?"
-                            " WHERE name = ?",
-                            [password_hash, now, 1 if make_guest else 0, user_id])
+                self._simple_update_one_txn(
+                    txn,
+                    "users",
+                    keyvalues={
+                        "name": user_id,
+                    },
+                    updatevalues={
+                        "password_hash": password_hash,
+                        "upgrade_ts": now,
+                        "is_guest": 1 if make_guest else 0,
+                        "appservice_id": appservice_id,
+                        "admin": 1 if admin else 0,
+                    }
+                )
             else:
-                txn.execute("INSERT INTO users "
-                            "("
-                            "   name,"
-                            "   password_hash,"
-                            "   creation_ts,"
-                            "   is_guest,"
-                            "   appservice_id"
-                            ") "
-                            "VALUES (?,?,?,?,?)",
-                            [
-                                user_id,
-                                password_hash,
-                                now,
-                                1 if make_guest else 0,
-                                appservice_id,
-                            ])
+                self._simple_insert_txn(
+                    txn,
+                    "users",
+                    values={
+                        "name": user_id,
+                        "password_hash": password_hash,
+                        "creation_ts": now,
+                        "is_guest": 1 if make_guest else 0,
+                        "appservice_id": appservice_id,
+                        "admin": 1 if admin else 0,
+                    }
+                )
         except self.database_engine.module.IntegrityError:
             raise StoreError(
                 400, "User ID already taken.", errcode=Codes.USER_IN_USE
@@ -384,6 +390,15 @@ class RegistrationStore(SQLBaseStore):
             defer.returnValue(ret['user_id'])
         defer.returnValue(None)
 
+    def user_delete_threepids(self, user_id):
+        return self._simple_delete(
+            "user_threepids",
+            keyvalues={
+                "user_id": user_id,
+            },
+            desc="user_delete_threepids",
+        )
+
     @defer.inlineCallbacks
     def count_all_users(self):
         """Counts all users registered on the homeserver."""
diff --git a/synapse/storage/room.py b/synapse/storage/room.py
index 97f9f1929c..8251f58670 100644
--- a/synapse/storage/room.py
+++ b/synapse/storage/room.py
@@ -18,7 +18,6 @@ from twisted.internet import defer
 from synapse.api.errors import StoreError
 
 from ._base import SQLBaseStore
-from synapse.util.caches.descriptors import cachedInlineCallbacks
 from .engines import PostgresEngine, Sqlite3Engine
 
 import collections
@@ -192,49 +191,6 @@ class RoomStore(SQLBaseStore):
             # This should be unreachable.
             raise Exception("Unrecognized database engine")
 
-    @cachedInlineCallbacks()
-    def get_room_name_and_aliases(self, room_id):
-        def get_room_name(txn):
-            sql = (
-                "SELECT name FROM room_names"
-                " INNER JOIN current_state_events USING (room_id, event_id)"
-                " WHERE room_id = ?"
-                " LIMIT 1"
-            )
-
-            txn.execute(sql, (room_id,))
-            rows = txn.fetchall()
-            if rows:
-                return rows[0][0]
-            else:
-                return None
-
-            return [row[0] for row in txn.fetchall()]
-
-        def get_room_aliases(txn):
-            sql = (
-                "SELECT content FROM current_state_events"
-                " INNER JOIN events USING (room_id, event_id)"
-                " WHERE room_id = ?"
-            )
-            txn.execute(sql, (room_id,))
-            return [row[0] for row in txn.fetchall()]
-
-        name = yield self.runInteraction("get_room_name", get_room_name)
-        alias_contents = yield self.runInteraction("get_room_aliases", get_room_aliases)
-
-        aliases = []
-
-        for c in alias_contents:
-            try:
-                content = json.loads(c)
-            except:
-                continue
-
-            aliases.extend(content.get('aliases', []))
-
-        defer.returnValue((name, aliases))
-
     def add_event_report(self, room_id, event_id, user_id, reason, content,
                          received_ts):
         next_id = self._event_reports_id_gen.get_next()
diff --git a/synapse/storage/schema/delta/33/remote_media_ts.py b/synapse/storage/schema/delta/33/remote_media_ts.py
new file mode 100644
index 0000000000..55ae43f395
--- /dev/null
+++ b/synapse/storage/schema/delta/33/remote_media_ts.py
@@ -0,0 +1,31 @@
+# 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.
+
+import time
+
+
+ALTER_TABLE = "ALTER TABLE remote_media_cache ADD COLUMN last_access_ts BIGINT"
+
+
+def run_create(cur, database_engine, *args, **kwargs):
+    cur.execute(ALTER_TABLE)
+
+
+def run_upgrade(cur, database_engine, *args, **kwargs):
+    cur.execute(
+        database_engine.convert_param_style(
+            "UPDATE remote_media_cache SET last_access_ts = ?"
+        ),
+        (int(time.time() * 1000),)
+    )
diff --git a/synapse/storage/stream.py b/synapse/storage/stream.py
index b9ad965fd6..c33ac5a8d7 100644
--- a/synapse/storage/stream.py
+++ b/synapse/storage/stream.py
@@ -40,6 +40,7 @@ from synapse.util.caches.descriptors import cached
 from synapse.api.constants import EventTypes
 from synapse.types import RoomStreamToken
 from synapse.util.logcontext import preserve_fn
+from synapse.storage.engines import PostgresEngine, Sqlite3Engine
 
 import logging
 
@@ -54,25 +55,43 @@ _STREAM_TOKEN = "stream"
 _TOPOLOGICAL_TOKEN = "topological"
 
 
-def lower_bound(token):
+def lower_bound(token, engine, inclusive=False):
+    inclusive = "=" if inclusive else ""
     if token.topological is None:
-        return "(%d < %s)" % (token.stream, "stream_ordering")
+        return "(%d <%s %s)" % (token.stream, inclusive, "stream_ordering")
     else:
-        return "(%d < %s OR (%d = %s AND %d < %s))" % (
+        if isinstance(engine, PostgresEngine):
+            # Postgres doesn't optimise ``(x < a) OR (x=a AND y<b)`` as well
+            # as it optimises ``(x,y) < (a,b)`` on multicolumn indexes. So we
+            # use the later form when running against postgres.
+            return "((%d,%d) <%s (%s,%s))" % (
+                token.topological, token.stream, inclusive,
+                "topological_ordering", "stream_ordering",
+            )
+        return "(%d < %s OR (%d = %s AND %d <%s %s))" % (
             token.topological, "topological_ordering",
             token.topological, "topological_ordering",
-            token.stream, "stream_ordering",
+            token.stream, inclusive, "stream_ordering",
         )
 
 
-def upper_bound(token):
+def upper_bound(token, engine, inclusive=True):
+    inclusive = "=" if inclusive else ""
     if token.topological is None:
-        return "(%d >= %s)" % (token.stream, "stream_ordering")
+        return "(%d >%s %s)" % (token.stream, inclusive, "stream_ordering")
     else:
-        return "(%d > %s OR (%d = %s AND %d >= %s))" % (
+        if isinstance(engine, PostgresEngine):
+            # Postgres doesn't optimise ``(x > a) OR (x=a AND y>b)`` as well
+            # as it optimises ``(x,y) > (a,b)`` on multicolumn indexes. So we
+            # use the later form when running against postgres.
+            return "((%d,%d) >%s (%s,%s))" % (
+                token.topological, token.stream, inclusive,
+                "topological_ordering", "stream_ordering",
+            )
+        return "(%d > %s OR (%d = %s AND %d >%s %s))" % (
             token.topological, "topological_ordering",
             token.topological, "topological_ordering",
-            token.stream, "stream_ordering",
+            token.stream, inclusive, "stream_ordering",
         )
 
 
@@ -308,18 +327,22 @@ class StreamStore(SQLBaseStore):
         args = [False, room_id]
         if direction == 'b':
             order = "DESC"
-            bounds = upper_bound(RoomStreamToken.parse(from_key))
+            bounds = upper_bound(
+                RoomStreamToken.parse(from_key), self.database_engine
+            )
             if to_key:
-                bounds = "%s AND %s" % (
-                    bounds, lower_bound(RoomStreamToken.parse(to_key))
-                )
+                bounds = "%s AND %s" % (bounds, lower_bound(
+                    RoomStreamToken.parse(to_key), self.database_engine
+                ))
         else:
             order = "ASC"
-            bounds = lower_bound(RoomStreamToken.parse(from_key))
+            bounds = lower_bound(
+                RoomStreamToken.parse(from_key), self.database_engine
+            )
             if to_key:
-                bounds = "%s AND %s" % (
-                    bounds, upper_bound(RoomStreamToken.parse(to_key))
-                )
+                bounds = "%s AND %s" % (bounds, upper_bound(
+                    RoomStreamToken.parse(to_key), self.database_engine
+                ))
 
         if int(limit) > 0:
             args.append(int(limit))
@@ -487,13 +510,13 @@ class StreamStore(SQLBaseStore):
             row["topological_ordering"], row["stream_ordering"],)
         )
 
-    def get_max_topological_token_for_stream_and_room(self, room_id, stream_key):
+    def get_max_topological_token(self, room_id, stream_key):
         sql = (
             "SELECT max(topological_ordering) FROM events"
             " WHERE room_id = ? AND stream_ordering < ?"
         )
         return self._execute(
-            "get_max_topological_token_for_stream_and_room", None,
+            "get_max_topological_token", None,
             sql, room_id, stream_key,
         ).addCallback(
             lambda r: r[0][0] if r else 0
@@ -586,32 +609,60 @@ class StreamStore(SQLBaseStore):
             retcols=["stream_ordering", "topological_ordering"],
         )
 
-        stream_ordering = results["stream_ordering"]
-        topological_ordering = results["topological_ordering"]
-
-        query_before = (
-            "SELECT topological_ordering, stream_ordering, event_id FROM events"
-            " WHERE room_id = ? AND (topological_ordering < ?"
-            " OR (topological_ordering = ? AND stream_ordering < ?))"
-            " ORDER BY topological_ordering DESC, stream_ordering DESC"
-            " LIMIT ?"
+        token = RoomStreamToken(
+            results["topological_ordering"],
+            results["stream_ordering"],
         )
 
-        query_after = (
-            "SELECT topological_ordering, stream_ordering, event_id FROM events"
-            " WHERE room_id = ? AND (topological_ordering > ?"
-            " OR (topological_ordering = ? AND stream_ordering > ?))"
-            " ORDER BY topological_ordering ASC, stream_ordering ASC"
-            " LIMIT ?"
-        )
+        if isinstance(self.database_engine, Sqlite3Engine):
+            # SQLite3 doesn't optimise ``(x < a) OR (x = a AND y < b)``
+            # So we give pass it to SQLite3 as the UNION ALL of the two queries.
+
+            query_before = (
+                "SELECT topological_ordering, stream_ordering, event_id FROM events"
+                " WHERE room_id = ? AND topological_ordering < ?"
+                " UNION ALL"
+                " SELECT topological_ordering, stream_ordering, event_id FROM events"
+                " WHERE room_id = ? AND topological_ordering = ? AND stream_ordering < ?"
+                " ORDER BY topological_ordering DESC, stream_ordering DESC LIMIT ?"
+            )
+            before_args = (
+                room_id, token.topological,
+                room_id, token.topological, token.stream,
+                before_limit,
+            )
 
-        txn.execute(
-            query_before,
-            (
-                room_id, topological_ordering, topological_ordering,
-                stream_ordering, before_limit,
+            query_after = (
+                "SELECT topological_ordering, stream_ordering, event_id FROM events"
+                " WHERE room_id = ? AND topological_ordering > ?"
+                " UNION ALL"
+                " SELECT topological_ordering, stream_ordering, event_id FROM events"
+                " WHERE room_id = ? AND topological_ordering = ? AND stream_ordering > ?"
+                " ORDER BY topological_ordering ASC, stream_ordering ASC LIMIT ?"
             )
-        )
+            after_args = (
+                room_id, token.topological,
+                room_id, token.topological, token.stream,
+                after_limit,
+            )
+        else:
+            query_before = (
+                "SELECT topological_ordering, stream_ordering, event_id FROM events"
+                " WHERE room_id = ? AND %s"
+                " ORDER BY topological_ordering DESC, stream_ordering DESC LIMIT ?"
+            ) % (upper_bound(token, self.database_engine, inclusive=False),)
+
+            before_args = (room_id, before_limit)
+
+            query_after = (
+                "SELECT topological_ordering, stream_ordering, event_id FROM events"
+                " WHERE room_id = ? AND %s"
+                " ORDER BY topological_ordering ASC, stream_ordering ASC LIMIT ?"
+            ) % (lower_bound(token, self.database_engine, inclusive=False),)
+
+            after_args = (room_id, after_limit)
+
+        txn.execute(query_before, before_args)
 
         rows = self.cursor_to_dict(txn)
         events_before = [r["event_id"] for r in rows]
@@ -623,17 +674,11 @@ class StreamStore(SQLBaseStore):
             ))
         else:
             start_token = str(RoomStreamToken(
-                topological_ordering,
-                stream_ordering - 1,
+                token.topological,
+                token.stream - 1,
             ))
 
-        txn.execute(
-            query_after,
-            (
-                room_id, topological_ordering, topological_ordering,
-                stream_ordering, after_limit,
-            )
-        )
+        txn.execute(query_after, after_args)
 
         rows = self.cursor_to_dict(txn)
         events_after = [r["event_id"] for r in rows]
@@ -644,10 +689,7 @@ class StreamStore(SQLBaseStore):
                 rows[-1]["stream_ordering"],
             ))
         else:
-            end_token = str(RoomStreamToken(
-                topological_ordering,
-                stream_ordering,
-            ))
+            end_token = str(token)
 
         return {
             "before": {
diff --git a/synapse/util/async.py b/synapse/util/async.py
index 40be7fe7e3..c84b23ff46 100644
--- a/synapse/util/async.py
+++ b/synapse/util/async.py
@@ -194,3 +194,85 @@ class Linearizer(object):
                     self.key_to_defer.pop(key, None)
 
         defer.returnValue(_ctx_manager())
+
+
+class ReadWriteLock(object):
+    """A deferred style read write lock.
+
+    Example:
+
+        with (yield read_write_lock.read("test_key")):
+            # do some work
+    """
+
+    # IMPLEMENTATION NOTES
+    #
+    # We track the most recent queued reader and writer deferreds (which get
+    # resolved when they release the lock).
+    #
+    # Read: We know its safe to acquire a read lock when the latest writer has
+    # been resolved. The new reader is appeneded to the list of latest readers.
+    #
+    # Write: We know its safe to acquire the write lock when both the latest
+    # writers and readers have been resolved. The new writer replaces the latest
+    # writer.
+
+    def __init__(self):
+        # Latest readers queued
+        self.key_to_current_readers = {}
+
+        # Latest writer queued
+        self.key_to_current_writer = {}
+
+    @defer.inlineCallbacks
+    def read(self, key):
+        new_defer = defer.Deferred()
+
+        curr_readers = self.key_to_current_readers.setdefault(key, set())
+        curr_writer = self.key_to_current_writer.get(key, None)
+
+        curr_readers.add(new_defer)
+
+        # We wait for the latest writer to finish writing. We can safely ignore
+        # any existing readers... as they're readers.
+        yield curr_writer
+
+        @contextmanager
+        def _ctx_manager():
+            try:
+                yield
+            finally:
+                new_defer.callback(None)
+                self.key_to_current_readers.get(key, set()).discard(new_defer)
+
+        defer.returnValue(_ctx_manager())
+
+    @defer.inlineCallbacks
+    def write(self, key):
+        new_defer = defer.Deferred()
+
+        curr_readers = self.key_to_current_readers.get(key, set())
+        curr_writer = self.key_to_current_writer.get(key, None)
+
+        # We wait on all latest readers and writer.
+        to_wait_on = list(curr_readers)
+        if curr_writer:
+            to_wait_on.append(curr_writer)
+
+        # We can clear the list of current readers since the new writer waits
+        # for them to finish.
+        curr_readers.clear()
+        self.key_to_current_writer[key] = new_defer
+
+        yield defer.gatherResults(to_wait_on)
+
+        @contextmanager
+        def _ctx_manager():
+            try:
+                yield
+            finally:
+                new_defer.callback(None)
+                if self.key_to_current_writer[key] == new_defer:
+                    self.key_to_current_writer.pop(key)
+
+        defer.returnValue(_ctx_manager())
diff --git a/synapse/util/presentable_names.py b/synapse/util/presentable_names.py
index a6866f6117..4c54812e6f 100644
--- a/synapse/util/presentable_names.py
+++ b/synapse/util/presentable_names.py
@@ -25,7 +25,8 @@ ALIAS_RE = re.compile(r"^#.*:.+$")
 ALL_ALONE = "Empty Room"
 
 
-def calculate_room_name(room_state, user_id, fallback_to_members=True):
+def calculate_room_name(room_state, user_id, fallback_to_members=True,
+                        fallback_to_single_member=True):
     """
     Works out a user-facing name for the given room as per Matrix
     spec recommendations.
@@ -129,6 +130,8 @@ def calculate_room_name(room_state, user_id, fallback_to_members=True):
                 return name_from_member_event(all_members[0])
         else:
             return ALL_ALONE
+    elif len(other_members) == 1 and not fallback_to_single_member:
+        return None
     else:
         return descriptor_from_member_events(other_members)
 
diff --git a/tests/replication/slave/storage/test_events.py b/tests/replication/slave/storage/test_events.py
index 17587fda00..f33e6f60fb 100644
--- a/tests/replication/slave/storage/test_events.py
+++ b/tests/replication/slave/storage/test_events.py
@@ -59,47 +59,6 @@ class SlavedEventStoreTestCase(BaseSlavedStoreTestCase):
         [unpatch() for unpatch in self.unpatches]
 
     @defer.inlineCallbacks
-    def test_room_name_and_aliases(self):
-        create = yield self.persist(type="m.room.create", key="", creator=USER_ID)
-        yield self.persist(type="m.room.member", key=USER_ID, membership="join")
-        yield self.persist(type="m.room.name", key="", name="name1")
-        yield self.persist(
-            type="m.room.aliases", key="blue", aliases=["#1:blue"]
-        )
-        yield self.replicate()
-        yield self.check(
-            "get_room_name_and_aliases", (ROOM_ID,), ("name1", ["#1:blue"])
-        )
-
-        # Set the room name.
-        yield self.persist(type="m.room.name", key="", name="name2")
-        yield self.replicate()
-        yield self.check(
-            "get_room_name_and_aliases", (ROOM_ID,), ("name2", ["#1:blue"])
-        )
-
-        # Set the room aliases.
-        yield self.persist(
-            type="m.room.aliases", key="blue", aliases=["#2:blue"]
-        )
-        yield self.replicate()
-        yield self.check(
-            "get_room_name_and_aliases", (ROOM_ID,), ("name2", ["#2:blue"])
-        )
-
-        # Leave and join the room clobbering the state.
-        yield self.persist(type="m.room.member", key=USER_ID, membership="leave")
-        yield self.persist(
-            type="m.room.member", key=USER_ID, membership="join",
-            reset_state=[create]
-        )
-        yield self.replicate()
-
-        yield self.check(
-            "get_room_name_and_aliases", (ROOM_ID,), (None, [])
-        )
-
-    @defer.inlineCallbacks
     def test_room_members(self):
         create = yield self.persist(type="m.room.create", key="", creator=USER_ID)
         yield self.replicate()
diff --git a/tests/util/test_rwlock.py b/tests/util/test_rwlock.py
new file mode 100644
index 0000000000..1d745ae1a7
--- /dev/null
+++ b/tests/util/test_rwlock.py
@@ -0,0 +1,85 @@
+# -*- coding: utf-8 -*-
+# 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.
+
+
+from tests import unittest
+
+from synapse.util.async import ReadWriteLock
+
+
+class ReadWriteLockTestCase(unittest.TestCase):
+
+    def _assert_called_before_not_after(self, lst, first_false):
+        for i, d in enumerate(lst[:first_false]):
+            self.assertTrue(d.called, msg="%d was unexpectedly false" % i)
+
+        for i, d in enumerate(lst[first_false:]):
+            self.assertFalse(
+                d.called, msg="%d was unexpectedly true" % (i + first_false)
+            )
+
+    def test_rwlock(self):
+        rwlock = ReadWriteLock()
+
+        key = object()
+
+        ds = [
+            rwlock.read(key),   # 0
+            rwlock.read(key),   # 1
+            rwlock.write(key),  # 2
+            rwlock.write(key),  # 3
+            rwlock.read(key),   # 4
+            rwlock.read(key),   # 5
+            rwlock.write(key),  # 6
+        ]
+
+        self._assert_called_before_not_after(ds, 2)
+
+        with ds[0].result:
+            self._assert_called_before_not_after(ds, 2)
+        self._assert_called_before_not_after(ds, 2)
+
+        with ds[1].result:
+            self._assert_called_before_not_after(ds, 2)
+        self._assert_called_before_not_after(ds, 3)
+
+        with ds[2].result:
+            self._assert_called_before_not_after(ds, 3)
+        self._assert_called_before_not_after(ds, 4)
+
+        with ds[3].result:
+            self._assert_called_before_not_after(ds, 4)
+        self._assert_called_before_not_after(ds, 6)
+
+        with ds[5].result:
+            self._assert_called_before_not_after(ds, 6)
+        self._assert_called_before_not_after(ds, 6)
+
+        with ds[4].result:
+            self._assert_called_before_not_after(ds, 6)
+        self._assert_called_before_not_after(ds, 7)
+
+        with ds[6].result:
+            pass
+
+        d = rwlock.write(key)
+        self.assertTrue(d.called)
+        with d.result:
+            pass
+
+        d = rwlock.read(key)
+        self.assertTrue(d.called)
+        with d.result:
+            pass
diff --git a/tests/utils.py b/tests/utils.py
index 6e41ae1ff6..ed547bc39b 100644
--- a/tests/utils.py
+++ b/tests/utils.py
@@ -56,6 +56,7 @@ def setup_test_homeserver(name="test", datastore=None, config=None, **kargs):
 
     config.use_frozen_dicts = True
     config.database_config = {"name": "sqlite3"}
+    config.ldap_enabled = False
 
     if "clock" not in kargs:
         kargs["clock"] = MockClock()