Remove support for invite_3pid_guest. (#5625)

This has never been documented, and I'm not sure it's ever been used outside
sytest.

It's quite a lot of poorly-maintained code, so I'd like to get rid of it.

For now I haven't removed the database table; I suggest we leave that for a
future clearout.

7 files changed, 3 insertions, 196 deletions

diff --git a/changelog.d/5625.removal b/changelog.d/5625.removal
new file mode 100644
index 0000000000..d33a778d69
--- /dev/null
+++ b/changelog.d/5625.removal
@@ -0,0 +1 @@
+Remove support for the `invite_3pid_guest` configuration setting.
diff --git a/synapse/config/registration.py b/synapse/config/registration.py
index 4a59e6ec90..b895c4e9f4 100644
--- a/synapse/config/registration.py
+++ b/synapse/config/registration.py
@@ -71,9 +71,8 @@ class RegistrationConfig(Config):
         self.default_identity_server = config.get("default_identity_server")
         self.allow_guest_access = config.get("allow_guest_access", False)
 
-        self.invite_3pid_guest = self.allow_guest_access and config.get(
-            "invite_3pid_guest", False
-        )
+        if config.get("invite_3pid_guest", False):
+            raise ConfigError("invite_3pid_guest is no longer supported")
 
         self.auto_join_rooms = config.get("auto_join_rooms", [])
         for room_alias in self.auto_join_rooms:
diff --git a/synapse/handlers/register.py b/synapse/handlers/register.py
index e487b90c08..fd55eb1654 100644
--- a/synapse/handlers/register.py
+++ b/synapse/handlers/register.py
@@ -557,36 +557,6 @@ class RegistrationHandler(BaseHandler):
         defer.returnValue((user_id, token))
 
     @defer.inlineCallbacks
-    def get_or_register_3pid_guest(self, medium, address, inviter_user_id):
-        """Get a guest access token for a 3PID, creating a guest account if
-        one doesn't already exist.
-
-        Args:
-            medium (str)
-            address (str)
-            inviter_user_id (str): The user ID who is trying to invite the
-                3PID
-
-        Returns:
-            Deferred[(str, str)]: A 2-tuple of `(user_id, access_token)` of the
-            3PID guest account.
-        """
-        access_token = yield self.store.get_3pid_guest_access_token(medium, address)
-        if access_token:
-            user_info = yield self.auth.get_user_by_access_token(access_token)
-
-            defer.returnValue((user_info["user"].to_string(), access_token))
-
-        user_id, access_token = yield self.register(
-            generate_token=True, make_guest=True
-        )
-        access_token = yield self.store.save_or_get_3pid_guest_access_token(
-            medium, address, access_token, inviter_user_id
-        )
-
-        defer.returnValue((user_id, access_token))
-
-    @defer.inlineCallbacks
     def _join_user_to_room(self, requester, room_identifier):
         room_id = None
         room_member_handler = self.hs.get_room_member_handler()
diff --git a/synapse/handlers/room_member.py b/synapse/handlers/room_member.py
index 66b05b4732..679daaa074 100644
--- a/synapse/handlers/room_member.py
+++ b/synapse/handlers/room_member.py
@@ -119,24 +119,6 @@ class RoomMemberHandler(object):
         raise NotImplementedError()
 
     @abc.abstractmethod
-    def get_or_register_3pid_guest(self, requester, medium, address, inviter_user_id):
-        """Get a guest access token for a 3PID, creating a guest account if
-        one doesn't already exist.
-
-        Args:
-            requester (Requester)
-            medium (str)
-            address (str)
-            inviter_user_id (str): The user ID who is trying to invite the
-                3PID
-
-        Returns:
-            Deferred[(str, str)]: A 2-tuple of `(user_id, access_token)` of the
-            3PID guest account.
-        """
-        raise NotImplementedError()
-
-    @abc.abstractmethod
     def _user_joined_room(self, target, room_id):
         """Notifies distributor on master process that the user has joined the
         room.
@@ -890,21 +872,6 @@ class RoomMemberHandler(object):
             "sender_avatar_url": inviter_avatar_url,
         }
 
-        if self.config.invite_3pid_guest:
-            guest_user_id, guest_access_token = yield self.get_or_register_3pid_guest(
-                requester=requester,
-                medium=medium,
-                address=address,
-                inviter_user_id=inviter_user_id,
-            )
-
-            invite_config.update(
-                {
-                    "guest_access_token": guest_access_token,
-                    "guest_user_id": guest_user_id,
-                }
-            )
-
         data = yield self.simple_http_client.post_urlencoded_get_json(
             is_url, invite_config
         )
@@ -1010,12 +977,6 @@ class RoomMemberMasterHandler(RoomMemberHandler):
             yield self.store.locally_reject_invite(target.to_string(), room_id)
             defer.returnValue({})
 
-    def get_or_register_3pid_guest(self, requester, medium, address, inviter_user_id):
-        """Implements RoomMemberHandler.get_or_register_3pid_guest
-        """
-        rg = self.registration_handler
-        return rg.get_or_register_3pid_guest(medium, address, inviter_user_id)
-
     def _user_joined_room(self, target, room_id):
         """Implements RoomMemberHandler._user_joined_room
         """
diff --git a/synapse/handlers/room_member_worker.py b/synapse/handlers/room_member_worker.py
index da501f38c0..fc873a3ba6 100644
--- a/synapse/handlers/room_member_worker.py
+++ b/synapse/handlers/room_member_worker.py
@@ -20,7 +20,6 @@ from twisted.internet import defer
 from synapse.api.errors import SynapseError
 from synapse.handlers.room_member import RoomMemberHandler
 from synapse.replication.http.membership import (
-    ReplicationRegister3PIDGuestRestServlet as Repl3PID,
     ReplicationRemoteJoinRestServlet as ReplRemoteJoin,
     ReplicationRemoteRejectInviteRestServlet as ReplRejectInvite,
     ReplicationUserJoinedLeftRoomRestServlet as ReplJoinedLeft,
@@ -33,7 +32,6 @@ class RoomMemberWorkerHandler(RoomMemberHandler):
     def __init__(self, hs):
         super(RoomMemberWorkerHandler, self).__init__(hs)
 
-        self._get_register_3pid_client = Repl3PID.make_client(hs)
         self._remote_join_client = ReplRemoteJoin.make_client(hs)
         self._remote_reject_client = ReplRejectInvite.make_client(hs)
         self._notify_change_client = ReplJoinedLeft.make_client(hs)
@@ -80,13 +78,3 @@ class RoomMemberWorkerHandler(RoomMemberHandler):
         return self._notify_change_client(
             user_id=target.to_string(), room_id=room_id, change="left"
         )
-
-    def get_or_register_3pid_guest(self, requester, medium, address, inviter_user_id):
-        """Implements RoomMemberHandler.get_or_register_3pid_guest
-        """
-        return self._get_register_3pid_client(
-            requester=requester,
-            medium=medium,
-            address=address,
-            inviter_user_id=inviter_user_id,
-        )
diff --git a/synapse/replication/http/membership.py b/synapse/replication/http/membership.py
index 0a76a3762f..2d9cbbaefc 100644
--- a/synapse/replication/http/membership.py
+++ b/synapse/replication/http/membership.py
@@ -156,70 +156,6 @@ class ReplicationRemoteRejectInviteRestServlet(ReplicationEndpoint):
         defer.returnValue((200, ret))
 
 
-class ReplicationRegister3PIDGuestRestServlet(ReplicationEndpoint):
-    """Gets/creates a guest account for given 3PID.
-
-    Request format:
-
-        POST /_synapse/replication/get_or_register_3pid_guest/
-
-        {
-            "requester": ...,
-            "medium": ...,
-            "address": ...,
-            "inviter_user_id": ...
-        }
-    """
-
-    NAME = "get_or_register_3pid_guest"
-    PATH_ARGS = ()
-
-    def __init__(self, hs):
-        super(ReplicationRegister3PIDGuestRestServlet, self).__init__(hs)
-
-        self.registeration_handler = hs.get_registration_handler()
-        self.store = hs.get_datastore()
-        self.clock = hs.get_clock()
-
-    @staticmethod
-    def _serialize_payload(requester, medium, address, inviter_user_id):
-        """
-        Args:
-            requester(Requester)
-            medium (str)
-            address (str)
-            inviter_user_id (str): The user ID who is trying to invite the
-                3PID
-        """
-        return {
-            "requester": requester.serialize(),
-            "medium": medium,
-            "address": address,
-            "inviter_user_id": inviter_user_id,
-        }
-
-    @defer.inlineCallbacks
-    def _handle_request(self, request):
-        content = parse_json_object_from_request(request)
-
-        medium = content["medium"]
-        address = content["address"]
-        inviter_user_id = content["inviter_user_id"]
-
-        requester = Requester.deserialize(self.store, content["requester"])
-
-        if requester.user:
-            request.authenticated_entity = requester.user.to_string()
-
-        logger.info("get_or_register_3pid_guest: %r", content)
-
-        ret = yield self.registeration_handler.get_or_register_3pid_guest(
-            medium, address, inviter_user_id
-        )
-
-        defer.returnValue((200, ret))
-
-
 class ReplicationUserJoinedLeftRoomRestServlet(ReplicationEndpoint):
     """Notifies that a user has joined or left the room
 
@@ -272,5 +208,4 @@ class ReplicationUserJoinedLeftRoomRestServlet(ReplicationEndpoint):
 def register_servlets(hs, http_server):
     ReplicationRemoteJoinRestServlet(hs).register(http_server)
     ReplicationRemoteRejectInviteRestServlet(hs).register(http_server)
-    ReplicationRegister3PIDGuestRestServlet(hs).register(http_server)
     ReplicationUserJoinedLeftRoomRestServlet(hs).register(http_server)
diff --git a/synapse/storage/registration.py b/synapse/storage/registration.py
index 13a3d5208b..aea5b3276b 100644
--- a/synapse/storage/registration.py
+++ b/synapse/storage/registration.py
@@ -433,19 +433,6 @@ class RegistrationWorkerStore(SQLBaseStore):
         )
 
     @defer.inlineCallbacks
-    def get_3pid_guest_access_token(self, medium, address):
-        ret = yield self._simple_select_one(
-            "threepid_guest_access_tokens",
-            {"medium": medium, "address": address},
-            ["guest_access_token"],
-            True,
-            "get_3pid_guest_access_token",
-        )
-        if ret:
-            defer.returnValue(ret["guest_access_token"])
-        defer.returnValue(None)
-
-    @defer.inlineCallbacks
     def get_user_id_by_threepid(self, medium, address, require_verified=False):
         """Returns user id from threepid
 
@@ -979,40 +966,6 @@ class RegistrationStore(
 
         defer.returnValue(res if res else False)
 
-    @defer.inlineCallbacks
-    def save_or_get_3pid_guest_access_token(
-        self, medium, address, access_token, inviter_user_id
-    ):
-        """
-        Gets the 3pid's guest access token if exists, else saves access_token.
-
-        Args:
-            medium (str): Medium of the 3pid. Must be "email".
-            address (str): 3pid address.
-            access_token (str): The access token to persist if none is
-                already persisted.
-            inviter_user_id (str): User ID of the inviter.
-
-        Returns:
-            deferred str: Whichever access token is persisted at the end
-            of this function call.
-        """
-
-        def insert(txn):
-            txn.execute(
-                "INSERT INTO threepid_guest_access_tokens "
-                "(medium, address, guest_access_token, first_inviter) "
-                "VALUES (?, ?, ?, ?)",
-                (medium, address, access_token, inviter_user_id),
-            )
-
-        try:
-            yield self.runInteraction("save_3pid_guest_access_token", insert)
-            defer.returnValue(access_token)
-        except self.database_engine.module.IntegrityError:
-            ret = yield self.get_3pid_guest_access_token(medium, address)
-            defer.returnValue(ret)
-
     def add_user_pending_deactivation(self, user_id):
         """
         Adds a user to the table of users who need to be parted from all the rooms they're