From f4f1cda928911197332a9a8bffcfb67c2b5b81e4 Mon Sep 17 00:00:00 2001
From: Matthew Hodgson <matthew@matrix.org>
Date: Thu, 28 Jun 2018 20:31:53 +0100
Subject: [PATCH] add ip_range_whitelist parameter to limit where ASes can
 connect from

---
 synapse/api/auth.py            |  6 ++++++
 synapse/appservice/__init__.py |  4 +++-
 synapse/config/appservice.py   | 11 ++++++++++-
 3 files changed, 19 insertions(+), 2 deletions(-)

diff --git a/synapse/api/auth.py b/synapse/api/auth.py
index 54186695c..088b4e8b6 100644
--- a/synapse/api/auth.py
+++ b/synapse/api/auth.py
@@ -19,6 +19,7 @@ from six import itervalues
 
 import pymacaroons
 from twisted.internet import defer
+from netaddr import IPAddress
 
 import synapse.types
 from synapse import event_auth
@@ -244,6 +245,11 @@ class Auth(object):
         if app_service is None:
             defer.returnValue((None, None))
 
+        if app_service.ip_range_whitelist:
+            ip_address = IPAddress(self.hs.get_ip_from_request(request))
+            if ip_address not in app_service.ip_range_whitelist:
+                defer.returnValue((None, None))
+
         if "user_id" not in request.args:
             defer.returnValue((app_service.sender, app_service))
 
diff --git a/synapse/appservice/__init__.py b/synapse/appservice/__init__.py
index d1c598622..328cbfa28 100644
--- a/synapse/appservice/__init__.py
+++ b/synapse/appservice/__init__.py
@@ -85,7 +85,8 @@ class ApplicationService(object):
     NS_LIST = [NS_USERS, NS_ALIASES, NS_ROOMS]
 
     def __init__(self, token, hostname, url=None, namespaces=None, hs_token=None,
-                 sender=None, id=None, protocols=None, rate_limited=True):
+                 sender=None, id=None, protocols=None, rate_limited=True,
+                 ip_range_whitelist=None):
         self.token = token
         self.url = url
         self.hs_token = hs_token
@@ -93,6 +94,7 @@ class ApplicationService(object):
         self.server_name = hostname
         self.namespaces = self._check_namespaces(namespaces)
         self.id = id
+        self.ip_range_whitelist = ip_range_whitelist
 
         if "|" in self.id:
             raise Exception("application service ID cannot contain '|' character")
diff --git a/synapse/config/appservice.py b/synapse/config/appservice.py
index 277305e18..89c07f202 100644
--- a/synapse/config/appservice.py
+++ b/synapse/config/appservice.py
@@ -17,6 +17,8 @@ from ._base import Config, ConfigError
 from synapse.appservice import ApplicationService
 from synapse.types import UserID
 
+from netaddr import IPSet
+
 import yaml
 import logging
 
@@ -154,6 +156,12 @@ def _load_appservice(hostname, as_info, config_filename):
             " will not receive events or queries.",
             config_filename,
         )
+
+    if as_info.get('ip_range_whitelist'):
+        ip_range_whitelist = IPSet(
+            as_info.get('ip_range_whitelist')
+        )
+
     return ApplicationService(
         token=as_info["as_token"],
         hostname=hostname,
@@ -163,5 +171,6 @@ def _load_appservice(hostname, as_info, config_filename):
         sender=user_id,
         id=as_info["id"],
         protocols=protocols,
-        rate_limited=rate_limited
+        rate_limited=rate_limited,
+        ip_range_whitelist=ip_range_whitelist,
     )