Add AuthenticatedHandler base class

app.py

@@ -18,6 +18,26 @@ from gitmgr import GitManagerConfiguration, GitManager
 startup_timestamp = datetime.now()
 
 
+class AuthenticatedHandler(tornado.web.RequestHandler, metaclass=ABCMeta):
+    # noinspection PyAttributeOutsideInit
+    def initialize(self, auth_provider=None):
+        self.auth_provider = auth_provider
+
+    def prepare(self):
+        if self.auth_provider is None:
+            return
+
+        # check authentication
+        auth_hdr = "Authentication"
+        if auth_hdr not in self.request.headers:
+            raise tornado.web.HTTPError(401, reason="authentication not provided")
+
+        tk = self.request.headers[auth_hdr]
+
+        if not self.auth_provider.validate_token(tk):
+            raise tornado.web.HTTPError(403, reason="invalid authentication token provided")
+
+
 class HealthHandler(tornado.web.RequestHandler, metaclass=ABCMeta):
     # noinspection PyAttributeOutsideInit
     def initialize(self, sources=None):