Implementing mixed content for forms posting to insecure location from secure ones

Source/core/html/HTMLFormElement.cpp

Index: Source/core/html/HTMLFormElement.cpp
diff --git a/Source/core/html/HTMLFormElement.cpp b/Source/core/html/HTMLFormElement.cpp
index 566e8c19e40f2aa73d99201f720d2b2f8ff7090b..68ee764490804718d33c45d976f13c2eccde754c 100644
--- a/Source/core/html/HTMLFormElement.cpp
+++ b/Source/core/html/HTMLFormElement.cpp
@@ -37,6 +37,10 @@
 #include "core/events/Event.h"
 #include "core/events/GenericEventQueue.h"
 #include "core/events/ScopedEventQueue.h"
+#include "core/frame/DOMWindow.h"
+#include "core/frame/LocalFrame.h"
+#include "core/frame/UseCounter.h"
+#include "core/frame/csp/ContentSecurityPolicy.h"
 #include "core/html/HTMLCollection.h"
 #include "core/html/HTMLDialogElement.h"
 #include "core/html/HTMLImageElement.h"
@@ -46,12 +50,10 @@
 #include "core/html/forms/FormController.h"
 #include "core/loader/FrameLoader.h"
 #include "core/loader/FrameLoaderClient.h"
-#include "core/frame/DOMWindow.h"
-#include "core/frame/LocalFrame.h"
-#include "core/frame/UseCounter.h"
-#include "core/frame/csp/ContentSecurityPolicy.h"
+#include "core/loader/MixedContentChecker.h"
 #include "core/rendering/RenderTextControl.h"
 #include "platform/UserGestureIndicator.h"
+#include "wtf/text/AtomicString.h"
 
 using namespace std;
 
@@ -59,6 +61,15 @@ namespace WebCore {
 
 using namespace HTMLNames;
 
+namespace {
+
+KURL getActionURL(const Document& document, const String& action)
+{
+    return action.isEmpty() ? document.url() : document.completeURL(action);
+}
+
+} // namespace
+
 HTMLFormElement::HTMLFormElement(Document& document)
     : HTMLElement(formTag, document)
 #if !ENABLE(OILPAN)
@@ -347,6 +358,13 @@ void HTMLFormElement::submit(Event* event, bool activateSubmitButton, bool proce
 
     m_wasUserSubmitted = processingUserGesture;
 
+    KURL actionURL = getActionURL(document(), m_attributes.action());
+    if (MixedContentChecker::isMixedContent(document().securityOrigin(), actionURL))
+        UseCounter::count(document(), UseCounter::MixedContentSubmittedForm);
+
+    if (!document().frame()->loader().mixedContentChecker()->canSubmitToInsecureForm(document().securityOrigin(), actionURL))
+        return;
+
     RefPtrWillBeRawPtr<HTMLFormControlElement> firstSuccessfulSubmitButton = nullptr;
     bool needButtonActivation = activateSubmitButton; // do we need to activate a submit button?
 
@@ -790,4 +808,20 @@ void HTMLFormElement::setDemoted(bool demoted)
     m_wasDemoted = demoted;
 }
 
+void HTMLFormElement::attributeChanged(const QualifiedName& name, const AtomicString& newValue, AttributeModificationReason)
+{
+    Element::attributeChanged(name, newValue);
+    if (name == actionAttr) {
+        // If the new action attribute is pointing to insecure "action" location from a secure page
+        // it is marked as "passive" mixed content. In other words, it will just
+        // show a console warning unless the user override the preferences to
+        // block all mixed content.
+        KURL actionURL = getActionURL(document(), m_attributes.action());
+        if (MixedContentChecker::isMixedContent(document().securityOrigin(), actionURL)) {
+            document().frame()->loader().mixedContentChecker()->canSubmitToInsecureForm(document().securityOrigin(), actionURL);
+            UseCounter::count(document(), UseCounter::MixedContentForm);
+        }
+    }

[abarth-chromium, 2014/06/07 08:59:50]

Is there a reason to trigger this use counter for mixed content action URLs if
the form is never submitted?  It seems like we care more about how often users
actually submit mixed content forms.

[mhm, 2014/06/09 15:55:35]

mkwst@ suggested that we need to count three things; (i) how many forms we see.
(ii) how many forms have mixed content. (iii) how many forms have mixed content
and are submitted.

This can be useful when we see so many mixed content forms but a very small
fraction of them git submitted, we can decide to treat this as an "active" mixed
content as it will affect a very small number of users.

On 2014/06/07 08:59:50, abarth wrote:

+}
+
 } // namespace