Send users a server notice about consent

When a user first syncs, we will send them a server notice asking them to
consent to the privacy policy if they have not already done so.

2 files changed, 159 insertions, 0 deletions

diff --git a/synapse/server_notices/consent_server_notices.py b/synapse/server_notices/consent_server_notices.py
new file mode 100644
index 0000000000..e9098aef27
--- /dev/null
+++ b/synapse/server_notices/consent_server_notices.py
@@ -0,0 +1,101 @@
+# -*- coding: utf-8 -*-
+# Copyright 2018 New Vector Ltd
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#     http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+import logging
+
+from twisted.internet import defer
+
+from synapse.api.errors import SynapseError
+from synapse.config import ConfigError
+
+logger = logging.getLogger(__name__)
+
+
+class ConsentServerNotices(object):
+    """Keeps track of whether we need to send users server_notices about
+    privacy policy consent, and sends one if we do.
+    """
+    def __init__(self, hs):
+        """
+
+        Args:
+            hs (synapse.server.HomeServer):
+        """
+        self._server_notices_manager = hs.get_server_notices_manager()
+        self._store = hs.get_datastore()
+
+        self._current_consent_version = None
+        self._server_notice_content = None
+        self._users_in_progress = set()
+
+        consent_config = hs.config.consent_config
+        if consent_config is not None:
+            self._current_consent_version = str(consent_config["version"])
+            self._server_notice_content = consent_config.get(
+                "server_notice_content"
+            )
+
+        if self._server_notice_content is not None:
+            if not self._server_notices_manager.is_enabled():
+                raise ConfigError(
+                    "user_consent configuration requires server notices, but "
+                    "server notices are not enabled.",
+                )
+            if 'body' not in self._server_notice_content:
+                raise ConfigError(
+                    "user_consent server_notice_consent must contain a 'body' "
+                    "key.",
+                )
+
+    @defer.inlineCallbacks
+    def maybe_send_server_notice_to_user(self, user_id):
+        """Check if we need to send a notice to this user, and does so if so
+
+        Args:
+            user_id (str): user to check
+
+        Returns:
+            Deferred
+        """
+        if self._server_notice_content is None:
+            # not enabled
+            return
+
+        # make sure we don't send two messages to the same user at once
+        if user_id in self._users_in_progress:
+            return
+        self._users_in_progress.add(user_id)
+        try:
+            u = yield self._store.get_user_by_id(user_id)
+
+            if u["consent_version"] == self._current_consent_version:
+                # user has already consented
+                return
+
+            if u["consent_server_notice_sent"] == self._current_consent_version:
+                # we've already sent a notice to the user
+                return
+
+            # need to send a message
+            try:
+                yield self._server_notices_manager.send_notice(
+                    user_id, self._server_notice_content,
+                )
+                yield self._store.user_set_consent_server_notice_sent(
+                    user_id, self._current_consent_version,
+                )
+            except SynapseError as e:
+                logger.error("Error sending server notice about user consent: %s", e)
+        finally:
+            self._users_in_progress.remove(user_id)
diff --git a/synapse/server_notices/server_notices_sender.py b/synapse/server_notices/server_notices_sender.py
new file mode 100644
index 0000000000..9eade85851
--- /dev/null
+++ b/synapse/server_notices/server_notices_sender.py
@@ -0,0 +1,58 @@
+# -*- coding: utf-8 -*-
+# Copyright 2018 New Vector Ltd
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#     http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+from synapse.server_notices.consent_server_notices import ConsentServerNotices
+
+
+class ServerNoticesSender(object):
+    """A centralised place which sends server notices automatically when
+    Certain Events take place
+    """
+    def __init__(self, hs):
+        """
+
+        Args:
+            hs (synapse.server.HomeServer):
+        """
+        # todo: it would be nice to make this more dynamic
+        self._consent_server_notices = ConsentServerNotices(hs)
+
+    def on_user_syncing(self, user_id):
+        """Called when the user performs a sync operation.
+
+        This is only called when /sync (or /events) is called on the synapse
+        master. In a deployment with synchrotrons, on_user_ip is called
+
+        Args:
+            user_id (str): mxid of user who synced
+
+        Returns:
+            Deferred
+        """
+        return self._consent_server_notices.maybe_send_server_notice_to_user(
+            user_id,
+        )
+
+    def on_user_ip(self, user_id):
+        """Called when a worker process saw a client request.
+
+        Args:
+            user_id (str): mxid
+
+        Returns:
+            Deferred
+        """
+        return self._consent_server_notices.maybe_send_server_notice_to_user(
+            user_id,
+        )