Issue 4951 - Restrict request headers in XMLHttpRequest.Also test Accept-Encoding with th…

lib/compat.js

 /*
  * This file is part of Adblock Plus <https://adblockplus.org/>,
  * Copyright (C) 2006-2016 Eyeo GmbH
  *
  * Adblock Plus is free software: you can redistribute it and/or modify
  * it under the terms of the GNU General Public License version 3 as
  * published by the Free Software Foundation.
  *
  * Adblock Plus is distributed in the hope that it will be useful,
  * but WITHOUT ANY WARRANTY; without even the implied warranty of
@@ skipping 281 matching lines @@
   _loadHandlers: null,
   _errorHandlers: null,
   onload: null,
   onerror: null,
   status: 0,
   readyState: 0,
   responseText: null,
 
   // list taken from https://developer.mozilla.org/en-US/docs/Glossary/Forbidden_header_name
   _forbiddenRequestHeaders: {
     "accept-charset": true,

[Felix Dahlke, 2017/03/03 08:33:05]

The v8 version we use should support Set [1], it seems that'd be nicer to use
here. But I don't feel strong about that.

[1]:
https://developer.mozilla.org/de/docs/Web/JavaScript/Reference/Global_Objects...

[hub, 2017/03/03 13:44:16]

It seems not
C++ exception with description "ReferenceError: Set is not defined at
compat.js:301" thrown in SetUp().

:-(

     "accept-encoding": true,
     "access-control-request-headers": true,
     "access-control-request-method": true,
     "connection": true,
     "content-length": true,
     "cookie": true,
     "cookie2": true,
     "date": true,
     "dnt": true,
     "expect": true,
     "host": true,
     "keep-alive": true,
     "origin": true,
     "referer": true,
     "te": true,
     "trailer": true,
     "transfer-encoding": true,
     "upgrade": true,
     "via": true,
   },
   _forbiddenRequestHeadersRe: new RegExp("^(Proxy|Sec)-", "i"),
 
   _isRequestHeaderAllowed: function(header)
   {
-    if (this._forbiddenRequestHeaders.hasOwnProperty(header.toLowerCase())) {

[Felix Dahlke, 2017/03/03 08:33:05]

Nit: Opening braces go on their own line where possible, see:
https://adblockplus.org/coding-style

(Omitting the braces for single line bodies is also fine.)

[hub, 2017/03/03 13:44:16]

Acknowledged.

+    if (this._forbiddenRequestHeaders.hasOwnProperty(header.toLowerCase()))
       return false;
-    }
-    if (header.match(this._forbiddenRequestHeadersRe)) {
+    if (header.match(this._forbiddenRequestHeadersRe))
       return false;
-    }
+
     return true;
   },
 
   addEventListener: function(eventName, handler, capture)
   {
     var list;
     if (eventName == "load")
       list = this._loadHandlers;
     else if (eventName == "error")
       list = this._errorHandlers;
@@ skipping 66 matching lines @@
 
   overrideMimeType: function(mime)
   {
   },
 
   setRequestHeader: function(name, value)
   {
     if (this.readyState > 1)
       throw new Error("Cannot set request header after sending");
 
-    if (this._isRequestHeaderAllowed(name)) {
+    if (this._isRequestHeaderAllowed(name))
       this._requestHeaders[name] = value;
-    } else {
+    else
       console.warn("Attempt to set a forbidden header was denied: " + name);
-    }
   },
 
   getResponseHeader: function(name)
   {
     name = name.toLowerCase();
     if (!this._responseHeaders || !this._responseHeaders.hasOwnProperty(name))
       return null;
     else
       return this._responseHeaders[name];
   },
 
   channel:
   {
     status: -1,
     notificationCallbacks: {},
     loadFlags: 0,
     INHIBIT_CACHING: 0,
     VALIDATE_ALWAYS: 0,
     QueryInterface: function()
     {
       return this;
     }
   }
 };