4 files changed, 45 insertions, 3 deletions
diff --git a/synapse/api/auth.py b/synapse/api/auth.py
index 0054745363..b176db8ce1 100644
--- a/synapse/api/auth.py
+++ b/synapse/api/auth.py
@@ -306,6 +306,34 @@ class Auth(object):
         # Can optionally look elsewhere in the request (e.g. headers)
         try:
             access_token = request.args["access_token"][0]
+
+            # Check for application service tokens with a user_id override
+            try:
+                app_service = yield self.store.get_app_service_by_token(
+                    access_token
+                )
+                if not app_service:
+                    raise KeyError
+
+                user_id = app_service.sender
+                if "user_id" in request.args:
+                    user_id = request.args["user_id"][0]
+                    if not app_service.is_interested_in_user(user_id):
+                        raise AuthError(
+                            403,
+                            "Application service cannot masquerade as this user."
+                        )
+
+                if not user_id:
+                    raise KeyError
+
+                defer.returnValue(
+                    (UserID.from_string(user_id), ClientInfo("", ""))
+                )
+                return
+            except KeyError:
+                pass  # normal users won't have this query parameter set
+
             user_info = yield self.get_user_by_token(access_token)
             user = user_info["user"]
             device_id = user_info["device_id"]
@@ -344,8 +372,7 @@ class Auth(object):
         try:
             ret = yield self.store.get_user_by_token(token=token)
             if not ret:
-                raise StoreError()
-
+                raise StoreError(400, "Unknown token")
             user_info = {
                 "admin": bool(ret.get("admin", False)),
                 "device_id": ret.get("device_id"),
@@ -358,6 +385,18 @@ class Auth(object):
             raise AuthError(403, "Unrecognised access token.",
                             errcode=Codes.UNKNOWN_TOKEN)
 
+    @defer.inlineCallbacks
+    def get_appservice_by_req(self, request):
+        try:
+            token = request.args["access_token"][0]
+            service = yield self.store.get_app_service_by_token(token)
+            if not service:
+                raise AuthError(403, "Unrecognised access token.",
+                                errcode=Codes.UNKNOWN_TOKEN)
+            defer.returnValue(service)
+        except KeyError:
+            raise AuthError(403, "Missing access token.")
+
     def is_server_admin(self, user):
         return self.store.is_server_admin(user)
 
diff --git a/synapse/api/constants.py b/synapse/api/constants.py
index 0d3fc629af..420f963d91 100644
--- a/synapse/api/constants.py
+++ b/synapse/api/constants.py
@@ -59,6 +59,7 @@ class LoginType(object):
     EMAIL_URL = u"m.login.email.url"
     EMAIL_IDENTITY = u"m.login.email.identity"
     RECAPTCHA = u"m.login.recaptcha"
+    APPLICATION_SERVICE = u"m.login.application_service"
 
 
 class EventTypes(object):
diff --git a/synapse/api/errors.py b/synapse/api/errors.py
index 5041828f18..eddd889778 100644
--- a/synapse/api/errors.py
+++ b/synapse/api/errors.py
@@ -36,7 +36,8 @@ class Codes(object):
     CAPTCHA_NEEDED = "M_CAPTCHA_NEEDED"
     CAPTCHA_INVALID = "M_CAPTCHA_INVALID"
     MISSING_PARAM = "M_MISSING_PARAM",
-    TOO_LARGE = "M_TOO_LARGE"
+    TOO_LARGE = "M_TOO_LARGE",
+    EXCLUSIVE = "M_EXCLUSIVE"
 
 
 class CodeMessageException(RuntimeError):
diff --git a/synapse/api/urls.py b/synapse/api/urls.py
index 693c0efda6..9485719332 100644
--- a/synapse/api/urls.py
+++ b/synapse/api/urls.py
@@ -22,3 +22,4 @@ WEB_CLIENT_PREFIX = "/_matrix/client"
 CONTENT_REPO_PREFIX = "/_matrix/content"
 SERVER_KEY_PREFIX = "/_matrix/key/v1"
 MEDIA_PREFIX = "/_matrix/media/v1"
+APP_SERVICE_PREFIX = "/_matrix/appservice/v1"