Bug 519928 - IFRAME inside designMode disables JavaScript, breaking current clickjacking defenses; r=Olli.Pettay

2010-06-04 17:03:50 -04:00
parent a4bd3075f3
commit 3129224585
9 changed files with 220 additions and 69 deletions
--- a/docshell/base/nsDocShell.cpp
+++ b/docshell/base/nsDocShell.cpp
@@ -11166,3 +11166,97 @@ nsDocShell::GetPrintPreview(nsIWebBrowserPrint** aPrintPreview)
 #ifdef DEBUG
 unsigned long nsDocShell::gNumberOfDocShells = 0;
 #endif
+
+NS_IMETHODIMP
+nsDocShell::GetCanExecuteScripts(PRBool *aResult)
+{
+  NS_ENSURE_ARG_POINTER(aResult);
+  *aResult = PR_FALSE; // disallow by default
+
+  nsCOMPtr<nsIDocShell> docshell = this;
+  nsCOMPtr<nsIDocShellTreeItem> globalObjTreeItem =
+      do_QueryInterface(docshell);
+
+  if (globalObjTreeItem)
+  {
+      nsCOMPtr<nsIDocShellTreeItem> treeItem(globalObjTreeItem);
+      nsCOMPtr<nsIDocShellTreeItem> parentItem;
+      PRBool firstPass = PR_TRUE;
+      PRBool lookForParents = PR_FALSE;
+
+      // Walk up the docshell tree to see if any containing docshell disallows scripts
+      do
+      {
+          nsresult rv = docshell->GetAllowJavascript(aResult);
+          if (NS_FAILED(rv)) return rv;
+          if (!*aResult) {
+              nsDocShell* realDocshell = static_cast<nsDocShell*>(docshell.get());
+              if (realDocshell->mContentViewer) {
+                  nsIDocument* doc = realDocshell->mContentViewer->GetDocument();
+                  if (doc && doc->HasFlag(NODE_IS_EDITABLE) &&
+                      realDocshell->mEditorData) {
+                      nsCOMPtr<nsIEditingSession> editSession;
+                      realDocshell->mEditorData->GetEditingSession(getter_AddRefs(editSession));
+                      PRBool jsDisabled = PR_FALSE;
+                      if (editSession &&
+                          NS_SUCCEEDED(rv = editSession->GetJsAndPluginsDisabled(&jsDisabled))) {
+                          if (firstPass) {
+                              if (jsDisabled) {
+                                  // We have a docshell which has been explicitly set
+                                  // to design mode, so we disallow scripts.
+                                  return NS_OK;
+                              }
+                              // The docshell was not explicitly set to design mode,
+                              // so it must be so because a parent was explicitly
+                              // set to design mode.  We don't need to look at higher
+                              // docshells.
+                              *aResult = PR_TRUE;
+                              break;
+                          } else if (lookForParents && jsDisabled) {
+                              // If a parent was explicitly set to design mode,
+                              // we should allow script execution on the child.
+                              *aResult = PR_TRUE;
+                              break;
+                          }
+                          // If the child docshell allows scripting, and the
+                          // parent is inside design mode, we don't need to look
+                          // further.
+                          *aResult = PR_TRUE;
+                          return NS_OK;
+                      }
+                      NS_WARNING("The editing session does not work?");
+                      return NS_FAILED(rv) ? rv : NS_ERROR_FAILURE;
+                  }
+                  if (firstPass) {
+                      // Don't be too hard on docshells on the first pass.
+                      // There may be a parent docshell which has been set
+                      // to design mode, so look for it.
+                      lookForParents = PR_TRUE;
+                  } else {
+                      // We have a docshell which disallows scripts
+                      // and is not editable, so we shouldn't allow
+                      // scripts at all.
+                      return NS_OK;
+                  }
+              }
+          } else if (lookForParents) {
+              // The parent docshell was not explicitly set to design
+              // mode, so js on the child docshell was disabled for
+              // another reason.  Therefore, we need to disable js.
+              return NS_OK;
+          }
+          firstPass = PR_FALSE;
+
+          treeItem->GetParent(getter_AddRefs(parentItem));
+          treeItem.swap(parentItem);
+          docshell = do_QueryInterface(treeItem);
+#ifdef DEBUG
+          if (treeItem && !docshell) {
+            NS_ERROR("cannot get a docshell from a treeItem!");
+          }
+#endif // DEBUG
+      } while (treeItem && docshell);
+  }
+
+  return NS_OK;
+}