PS - Adjusting webRequest API for use in Public Sessions

extensions/browser/api/web_request/web_request_api.cc

Index: extensions/browser/api/web_request/web_request_api.cc
diff --git a/extensions/browser/api/web_request/web_request_api.cc b/extensions/browser/api/web_request/web_request_api.cc
index 8071003b9d416aff4a365fbc3b53ddbd6a3a5e63..8f2d6fdbdb1d0f1ad3e7130a50e2485d28bf4c39 100644
--- a/extensions/browser/api/web_request/web_request_api.cc
+++ b/extensions/browser/api/web_request/web_request_api.cc
@@ -23,6 +23,7 @@
 #include "base/strings/utf_string_conversions.h"
 #include "base/time/time.h"
 #include "base/values.h"
+#include "chromeos/login/login_state.h"
 #include "content/public/browser/browser_thread.h"
 #include "content/public/browser/resource_request_info.h"
 #include "content/public/browser/user_metrics.h"
@@ -339,6 +340,16 @@ bool ShouldHideEvent(void* browser_context,
                                              navigation_ui_data));
 }
 
+// Returns true if we're in a Public Session.
+bool IsPublicSession() {
+#if defined(OS_CHROMEOS)
+  if (chromeos::LoginState::IsInitialized()) {
+    return chromeos::LoginState::Get()->IsPublicSessionUser();
+  }
+#endif
+  return false;
+}
+
 }  // namespace
 
 WebRequestAPI::WebRequestAPI(content::BrowserContext* context)
@@ -1123,6 +1134,13 @@ void ExtensionWebRequestEventRouter::DispatchEventToListeners(
       cross_browser_context ? &listeners_[cross_browser_context][event_name]
                             : nullptr;
 
+  // In Public Sessions we want to restrict access to security or privacy
+  // sensitive data. Data is filtered for *all* listeners, not only extensions
+  // which are force-installed by policy.
+  if (IsPublicSession()) {
+    event_details->FilterForPublicSession();
+  }
+
   for (const EventListener::ID& id : *listener_ids) {
     // It's possible that the listener is no longer present. Check to make sure
     // it's still there.
@@ -2133,7 +2151,10 @@ WebRequestInternalAddEventListenerFunction::Run() {
     // http://www.example.com/bar/*.
     // For this reason we do only a coarse check here to warn the extension
     // developer if they do something obviously wrong.
-    if (extension->permissions_data()
+    // When we are in a Public Session, allow all URLs for webRequests initiated
+    // by a regular extension.
+    if (!(IsPublicSession() && extension->is_extension()) &&
+        extension->permissions_data()
             ->GetEffectiveHostPermissions()
             .is_empty() &&
         extension->permissions_data()
@@ -2197,6 +2218,16 @@ WebRequestInternalEventHandledFunction::Run() {
           extension_id_safe(), install_time));
     }
 
+    // In Public Session we only want to allow "cancel".
+    if (IsPublicSession() &&
+        (value->HasKey("redirectUrl") ||
+         value->HasKey(keys::kAuthCredentialsKey) ||
+         value->HasKey("requestHeaders") ||
+         value->HasKey("responseHeaders"))) {
+      OnError(event_name, sub_event_name, request_id, std::move(response));
+      return RespondNow(Error(keys::kInvalidPublicSessionBlockingResponse));
+    }
+
     if (value->HasKey("cancel")) {
       // Don't allow cancel mixed with other keys.
       if (value->size() != 1) {