Limit protection of clients[0-9]*.google.com to requests from browser.

extensions/browser/api/web_request/web_request_permissions.cc

Index: extensions/browser/api/web_request/web_request_permissions.cc
diff --git a/extensions/browser/api/web_request/web_request_permissions.cc b/extensions/browser/api/web_request/web_request_permissions.cc
index 8b2f2f49742858767d6cbab0465b34f81dd181df..53bb6713b62380e8fdf860f38f1e96dda94574b3 100644
--- a/extensions/browser/api/web_request/web_request_permissions.cc
+++ b/extensions/browser/api/web_request/web_request_permissions.cc
@@ -8,6 +8,7 @@
 #include "base/strings/string_util.h"
 #include "base/strings/stringprintf.h"
 #include "chromeos/login/login_state.h"
+#include "content/public/browser/child_process_security_policy.h"
 #include "content/public/browser/resource_request_info.h"
 #include "extensions/browser/extension_navigation_ui_data.h"
 #include "extensions/browser/guest_view/web_view/web_view_renderer_state.h"
@@ -42,11 +43,14 @@ bool g_allow_all_extension_locations_in_public_session = false;
 // Returns true if the URL is sensitive and requests to this URL must not be
 // modified/canceled by extensions, e.g. because it is targeted to the webstore
 // to check for updates, extension blacklisting, etc.
-bool IsSensitiveURL(const GURL& url) {
+bool IsSensitiveURL(const GURL& url,
+                    bool is_request_from_browser_or_webui_renderer) {
   // TODO(battre) Merge this, CanExtensionAccessURL and
   // PermissionsData::CanAccessPage into one function.
   bool sensitive_chrome_url = false;
-  const base::StringPiece& host = url.host_piece();
+  base::StringPiece host = url.host_piece();
+  while (host.ends_with("."))
+    host.remove_suffix(1u);
   const char kGoogleCom[] = "google.com";
   const char kClient[] = "clients";
   if (url.DomainIs(kGoogleCom)) {
@@ -54,23 +58,34 @@ bool IsSensitiveURL(const GURL& url) {
     // This protects requests to several internal services such as sync,
     // extension update pings, captive portal detection, fraudulent certificate
     // reporting, autofill and others.
-    if (base::StartsWith(host, kClient, base::CompareCase::SENSITIVE)) {
-      bool match = true;
-      for (base::StringPiece::const_iterator
-               i = host.begin() + strlen(kClient),
-               end = host.end() - (strlen(kGoogleCom) + 1);
-           i != end; ++i) {
-        if (!isdigit(*i)) {
+    //
+    // These URLs are only protected for requests from the browser and webui
+    // renderers, not for requests from common renderers, because
+    // clients*.google.com are also used by websites.
+    if (is_request_from_browser_or_webui_renderer) {
+      base::StringPiece::size_type pos = host.rfind(kClient);
+      if (pos != base::StringPiece::npos) {
+        bool match = true;
+        if (pos > 0 && host[pos - 1] != '.') {
           match = false;
-          break;
+        } else {
+          for (base::StringPiece::const_iterator
+                   i = host.begin() + pos + strlen(kClient),
+                   end = host.end() - (strlen(kGoogleCom) + 1);
+               i != end; ++i) {
+            if (!isdigit(*i)) {
+              match = false;
+              break;
+            }
+          }
         }
+        sensitive_chrome_url = sensitive_chrome_url || match;
       }
-      sensitive_chrome_url = sensitive_chrome_url || match;
     }
-    // This protects requests to safe browsing, link doctor, and possibly
-    // others.
+
+    // Safebrowsing and Chrome Webstore URLs are always protected, i.e. also
+    // for requests from common renderers.
     sensitive_chrome_url = sensitive_chrome_url ||
-                           url.DomainIs("clients.google.com") ||
                            url.DomainIs("sb-ssl.google.com") ||
                            (url.DomainIs("chrome.google.com") &&
                             base::StartsWith(url.path_piece(), "/webstore",
@@ -85,8 +100,13 @@ bool WebRequestPermissions::HideRequest(
     const extensions::InfoMap* extension_info_map,
     const net::URLRequest* request,
     extensions::ExtensionNavigationUIData* navigation_ui_data) {
-  // Hide requests from the Chrome WebStore App or signin process.
+  // Hide requests from the Chrome WebStore App, signin process and WebUI.
   const ResourceRequestInfo* info = ResourceRequestInfo::ForRequest(request);
+
+  // Requests from the browser and webui get special protection for
+  // clients*.google.com URLs.
+  bool is_request_from_browser = true;
+  bool is_request_from_webui_renderer = false;
   if (info) {
     int process_id = info->GetChildID();
     // Never hide requests from guest processes.
@@ -100,10 +120,17 @@ bool WebRequestPermissions::HideRequest(
                                                    process_id)) {
       return true;
     }
+
+    is_request_from_browser = false;
+    is_request_from_webui_renderer =
+        content::ChildProcessSecurityPolicy::GetInstance()->HasWebUIBindings(
+            process_id);
   }
 
   const GURL& url = request->url();
-  return IsSensitiveURL(url) || !HasWebRequestScheme(url);
+  return IsSensitiveURL(
+             url, is_request_from_browser || is_request_from_webui_renderer) ||
+         !HasWebRequestScheme(url);
 }
 
 // static