Rework Auth Plugins to Support HTTP Authfeature/http-auth-plugins

This commit reworks auth plugins slightly to enable
support for HTTP authentication.  By raising an
AuthenticationError, auth plugins can now return
HTTP responses to the upgrade request (such as 401).

Related to kanaka/noVNC#522

1 files changed, 24 insertions, 9 deletions

diff --git a/websockify/websocketproxy.py b/websockify/websocketproxy.py
index 029b6f3..46ab545 100755
--- a/websockify/websocketproxy.py
+++ b/websockify/websocketproxy.py
@@ -18,6 +18,7 @@ try:    from http.server import HTTPServer
 except: from BaseHTTPServer import HTTPServer
 import select
 from websockify import websocket
+from websockify import auth_plugins as auth
 try:
     from urllib.parse import parse_qs, urlparse
 except:
@@ -37,20 +38,34 @@ Traffic Legend:
     <  - Client send
     <. - Client send partial
 """
+    
+    def send_auth_error(self, ex):
+        self.send_response(ex.code, ex.msg)
+        self.send_header('Content-Type', 'text/html')
+        for name, val in ex.headers.items():
+            self.send_header(name, val)
+        
+        self.end_headers()
+    
+    def validate_connection(self):
+        if self.server.token_plugin: 
+            (self.server.target_host, self.server.target_port) = self.get_target(self.server.token_plugin, self.path)
+
+        if self.server.auth_plugin:
+            try:
+                self.server.auth_plugin.authenticate(
+                    headers=self.headers, target_host=self.server.target_host,
+                    target_port=self.server.target_port)
+            except auth.AuthenticationError:
+                ex = sys.exc_info()[1]
+                self.send_auth_error(ex)
+                raise
 
     def new_websocket_client(self):
         """
         Called after a new WebSocket connection has been established.
         """
-        # Checks if we receive a token, and look
-        # for a valid target for it then
-        if self.server.token_plugin:
-            (self.server.target_host, self.server.target_port) = self.get_target(self.server.token_plugin, self.path)
-
-        if self.server.auth_plugin:
-            self.server.auth_plugin.authenticate(
-                headers=self.headers, target_host=self.server.target_host,
-                target_port=self.server.target_port)
+        # Checking for a token is done in validate_connection()
 
         # Connect to the target
         if self.server.wrap_cmd: