chrome/renderer/extensions/resource_request_policy.cc

   1 // Copyright (c) 2012 The Chromium Authors. All rights reserved.
   2 // Use of this source code is governed by a BSD-style license that can be
   3 // found in the LICENSE file.
   4
   5 #include "chrome/renderer/extensions/resource_request_policy.h"
   6
   7 #include "base/logging.h"
   8 #include "base/strings/stringprintf.h"
   9 #include "chrome/common/extensions/manifest_url_handler.h"
  10 #include "chrome/common/url_constants.h"
  11 #include "content/public/common/page_transition_types.h"
  12 #include "extensions/common/constants.h"
  13 #include "extensions/common/extension.h"
  14 #include "extensions/common/extension_set.h"
  15 #include "extensions/common/manifest_handlers/icons_handler.h"
  16 #include "extensions/common/manifest_handlers/web_accessible_resources_info.h"
  17 #include "third_party/WebKit/public/platform/WebString.h"
  18 #include "third_party/WebKit/public/web/WebConsoleMessage.h"
  19 #include "third_party/WebKit/public/web/WebDocument.h"
  20 #include "third_party/WebKit/public/web/WebFrame.h"
  21 #include "url/gurl.h"
  22
  23 namespace extensions {
  24
  25 // This method does a security check whether chrome-extension:// URLs can be
  26 // requested by the renderer. Since this is in an untrusted process, the browser
  27 // has a similar check to enforce the policy, in case this process is exploited.
  28 // If you are changing this function, ensure equivalent checks are added to
  29 // extension_protocols.cc's AllowExtensionResourceLoad.
  30
  31 // static
  32 bool ResourceRequestPolicy::CanRequestResource(
  33     const GURL& resource_url,
  34     blink::WebFrame* frame,
  35     content::PageTransition transition_type,
  36     const ExtensionSet* loaded_extensions) {
  37   CHECK(resource_url.SchemeIs(extensions::kExtensionScheme));
  38
  39   const Extension* extension =
  40       loaded_extensions->GetExtensionOrAppByURL(resource_url);
  41   if (!extension) {
  42     // Allow the load in the case of a non-existent extension. We'll just get a
  43     // 404 from the browser process.
  44     return true;
  45   }
  46
  47   // Disallow loading of packaged resources for hosted apps. We don't allow
  48   // hybrid hosted/packaged apps. The one exception is access to icons, since
  49   // some extensions want to be able to do things like create their own
  50   // launchers.
  51   std::string resource_root_relative_path =
  52       resource_url.path().empty() ? std::string()
  53                                   : resource_url.path().substr(1);
  54   if (extension->is_hosted_app() &&
  55       !IconsInfo::GetIcons(extension)
  56           .ContainsPath(resource_root_relative_path)) {
  57     LOG(ERROR) << "Denying load of " << resource_url.spec() << " from "
  58                << "hosted app.";
  59     return false;
  60   }
  61
  62   // Disallow loading of extension resources which are not explicitly listed
  63   // as web accessible if the manifest version is 2 or greater.
  64   if (!WebAccessibleResourcesInfo::IsResourceWebAccessible(
  65           extension, resource_url.path())) {
  66     GURL frame_url = frame->document().url();
  67     GURL page_url = frame->top()->document().url();
  68
  69     // Exceptions are:
  70     // - empty origin (needed for some edge cases when we have empty origins)
  71     bool is_empty_origin = frame_url.is_empty();
  72     // - extensions requesting their own resources (frame_url check is for
  73     //     images, page_url check is for iframes)
  74     bool is_own_resource = frame_url.GetOrigin() == extension->url() ||
  75         page_url.GetOrigin() == extension->url();
  76     // - devtools (chrome-extension:// URLs are loaded into frames of devtools
  77     //     to support the devtools extension APIs)
  78     bool is_dev_tools = page_url.SchemeIs(content::kChromeDevToolsScheme) &&
  79                         !ManifestURL::GetDevToolsPage(extension).is_empty();
  80     bool transition_allowed =
  81         !content::PageTransitionIsWebTriggerable(transition_type);
  82     // - unreachable web page error page (to allow showing the icon of the
  83     //   unreachable app on this page)
  84     bool is_error_page = frame_url == GURL(content::kUnreachableWebDataURL);
  85
  86     if (!is_empty_origin && !is_own_resource &&
  87         !is_dev_tools && !transition_allowed && !is_error_page) {
  88       std::string message = base::StringPrintf(
  89           "Denying load of %s. Resources must be listed in the "
  90           "web_accessible_resources manifest key in order to be loaded by "
  91           "pages outside the extension.",
  92           resource_url.spec().c_str());
  93       frame->addMessageToConsole(
  94           blink::WebConsoleMessage(blink::WebConsoleMessage::LevelError,
  95                                     blink::WebString::fromUTF8(message)));
  96       return false;
  97     }
  98   }
  99
 100   return true;
 101 }
 102
 103 // static
 104 bool ResourceRequestPolicy::CanRequestExtensionResourceScheme(
 105     const GURL& resource_url,
 106     blink::WebFrame* frame) {
 107   CHECK(resource_url.SchemeIs(extensions::kExtensionResourceScheme));
 108
 109   GURL frame_url = frame->document().url();
 110   if (!frame_url.is_empty() &&
 111       !frame_url.SchemeIs(extensions::kExtensionScheme)) {
 112     std::string message = base::StringPrintf(
 113         "Denying load of %s. chrome-extension-resources:// can only be "
 114         "loaded from extensions.",
 115       resource_url.spec().c_str());
 116     frame->addMessageToConsole(
 117         blink::WebConsoleMessage(blink::WebConsoleMessage::LevelError,
 118                                   blink::WebString::fromUTF8(message)));
 119     return false;
 120   }
 121
 122   return true;
 123 }
 124
 125 ResourceRequestPolicy::ResourceRequestPolicy() {
 126 }
 127
 128 }  // namespace extensions