Restrict extensionview to chrome-extension://

extensions/browser/guest_view/extension_view/extension_view_guest.cc

Index: extensions/browser/guest_view/extension_view/extension_view_guest.cc
diff --git a/extensions/browser/guest_view/extension_view/extension_view_guest.cc b/extensions/browser/guest_view/extension_view/extension_view_guest.cc
index 952ec1331cfb1a9eacee3e86989253bd3f22326a..e526f17a76c8e1053ce5d8b6962076ac79530643 100644
--- a/extensions/browser/guest_view/extension_view/extension_view_guest.cc
+++ b/extensions/browser/guest_view/extension_view/extension_view_guest.cc
@@ -5,6 +5,8 @@
 #include "extensions/browser/guest_view/extension_view/extension_view_guest.h"
 
 #include "base/metrics/user_metrics.h"
+#include "components/crx_file/id_util.h"
+#include "content/public/browser/child_process_security_policy.h"
 #include "content/public/browser/render_process_host.h"
 #include "content/public/common/result_codes.h"
 #include "extensions/browser/api/extensions_api_client.h"
@@ -40,11 +42,20 @@ extensions::GuestViewBase* ExtensionViewGuest::Create(
 
 void ExtensionViewGuest::NavigateGuest(const std::string& src,
                                        bool force_navigation) {
-  if (src.empty())
+  GURL url = extension_url_.Resolve(src);
+
+  // Do not allow navigating a guest to schemes other than known safe schemes.
+  bool scheme_is_blocked =
+      (!content::ChildProcessSecurityPolicy::GetInstance()->IsWebSafeScheme(
+           url.scheme()) &&
+       !url.SchemeIs(url::kAboutScheme)) ||
+      url.SchemeIs(url::kJavaScriptScheme);
+  if (scheme_is_blocked || !url.is_valid()) {

[Fady Samuel, 2015/02/17 20:17:04]

I think a simpler check might be:

// If the URL is not valid or it's not about:blank and not the same origin as
the extension, then navigate to about:blank.
if (!url.is_valid() || ((url != GURL(url::kAboutBlankURL) && (url.GetOrigin() !=
extension_url_.GetOrigin()))) {
  NavigateGuest(url::kAboutBlankURL, true /* force_navigation */);
  return;
}

[apacible, 2015/02/17 23:02:58]

Sounds good. Changed.

+    NavigateGuest(url::kAboutBlankURL, true /* force_navigation */);
     return;
+  }
 
-  GURL url(src);
-  if (!url.is_valid() && !force_navigation && (url == view_page_))
+  if (!force_navigation && (view_page_ == url))
     return;
 
   web_contents()->GetRenderProcessHost()->FilterURL(false, &url);
@@ -63,20 +74,33 @@ bool ExtensionViewGuest::CanRunInDetachedState() const {
 void ExtensionViewGuest::CreateWebContents(
     const base::DictionaryValue& create_params,
     const WebContentsCreatedCallback& callback) {
-  std::string str;
-  if (!create_params.GetString(extensionview::kAttributeSrc, &str)) {
+  // Gets the extension ID.
+  create_params.GetString(extensionview::kAttributeExtension, &extension_id_);
+
+  if (!crx_file::id_util::IdIsValid(extension_id_)) {
+    callback.Run(nullptr);
+    return;
+  }
+
+  // Gets the extension URL.
+  extension_url_ =
+      extensions::Extension::GetBaseURLFromExtensionId(extension_id_);
+
+  if (!extension_url_.is_valid()) {
     callback.Run(nullptr);
     return;
   }
 
-  GURL source(str);
-  if (!source.is_valid()) {
+  // Get the src to build URL to render.
+  std::string src;
+  if (!create_params.GetString(extensionview::kAttributeSrc, &src)) {
     callback.Run(nullptr);
     return;
   }
 
   content::SiteInstance* view_site_instance =
-      content::SiteInstance::CreateForURL(browser_context(), source);
+      content::SiteInstance::CreateForURL(browser_context(),
+                                          extension_url_);
 
   WebContents::CreateParams params(browser_context(), view_site_instance);
   params.guest_delegate = this;