[tbb-commits] [tor-browser/tor-browser-45.1.0esr-6.0-1] Bug 18958: Spoof screen.orientation values

[gk at torproject.org]

commit a086a5d0070821b1c4dfd2492bdc993c91353a2b
Author: Arthur Edelstein <arthuredelstein at gmail.com>
Date:   Sun May 8 22:23:42 2016 -0700

    Bug 18958: Spoof screen.orientation values
    
    Make sure that
    screen.orientation.angle -> 0 and
    screen.orientation.type -> "landscape-primary"
    
    Also refactors screen.mozOrientation.
---
 dom/base/ScreenOrientation.cpp | 29 +++++++++++++++++++++++++++--
 dom/base/ScreenOrientation.h   |  2 ++
 dom/base/nsGlobalWindow.cpp    |  7 ++++---
 dom/base/nsScreen.cpp          | 38 ++++++++++++++++++++------------------
 4 files changed, 53 insertions(+), 23 deletions(-)

diff --git a/dom/base/ScreenOrientation.cpp b/dom/base/ScreenOrientation.cpp
index 868a1d5..fdea67a 100644
--- a/dom/base/ScreenOrientation.cpp
+++ b/dom/base/ScreenOrientation.cpp
@@ -15,6 +15,7 @@
 #include "mozilla/Preferences.h"
 
 #include "mozilla/dom/Promise.h"
+#include "nsContentUtils.h"
 
 using namespace mozilla;
 using namespace mozilla::dom;
@@ -403,18 +404,23 @@ ScreenOrientation::UnlockDeviceOrientation()
 OrientationType
 ScreenOrientation::DeviceType() const
 {
-  return mType;
+  return ShouldResistFingerprinting() ? OrientationType::Landscape_primary
+                                      : mType;
 }
 
 uint16_t
 ScreenOrientation::DeviceAngle() const
 {
-  return mAngle;
+  return ShouldResistFingerprinting() ? 0 : mAngle;
 }
 
 OrientationType
 ScreenOrientation::GetType(ErrorResult& aRv) const
 {
+  if (ShouldResistFingerprinting()) {
+    return OrientationType::Landscape_primary;
+  }
+
   nsIDocument* doc = GetResponsibleDocument();
   if (!doc) {
     aRv.Throw(NS_ERROR_UNEXPECTED);
@@ -427,6 +433,10 @@ ScreenOrientation::GetType(ErrorResult& aRv) const
 uint16_t
 ScreenOrientation::GetAngle(ErrorResult& aRv) const
 {
+  if (ShouldResistFingerprinting()) {
+    return 0;
+  }
+
   nsIDocument* doc = GetResponsibleDocument();
   if (!doc) {
     aRv.Throw(NS_ERROR_UNEXPECTED);
@@ -489,6 +499,10 @@ ScreenOrientation::GetResponsibleDocument() const
 void
 ScreenOrientation::Notify(const hal::ScreenConfiguration& aConfiguration)
 {
+  if (ShouldResistFingerprinting()) {
+    return;
+  }
+
   nsIDocument* doc = GetResponsibleDocument();
   if (!doc) {
     return;
@@ -564,6 +578,17 @@ ScreenOrientation::WrapObject(JSContext* aCx, JS::Handle<JSObject*> aGivenProto)
   return ScreenOrientationBinding::Wrap(aCx, this, aGivenProto);
 }
 
+bool
+ScreenOrientation::ShouldResistFingerprinting() const
+{
+  bool resist = false;
+  nsCOMPtr<nsPIDOMWindow> owner = GetOwner();
+  if (owner) {
+    resist = nsContentUtils::ShouldResistFingerprinting(owner->GetDocShell());
+  }
+  return resist;
+}
+
 NS_IMPL_ISUPPORTS(ScreenOrientation::VisibleEventListener, nsIDOMEventListener)
 
 NS_IMETHODIMP
diff --git a/dom/base/ScreenOrientation.h b/dom/base/ScreenOrientation.h
index afb5e77..a6e51c7 100644
--- a/dom/base/ScreenOrientation.h
+++ b/dom/base/ScreenOrientation.h
@@ -102,6 +102,8 @@ private:
 
   void DispatchChangeEvent();
 
+  bool ShouldResistFingerprinting() const;
+
   LockPermission GetLockOrientationPermission(bool aCheckSandbox) const;
 
   // Gets the responsible document as defined in the spec.
diff --git a/dom/base/nsGlobalWindow.cpp b/dom/base/nsGlobalWindow.cpp
index ed42538..6dc06b1 100644
--- a/dom/base/nsGlobalWindow.cpp
+++ b/dom/base/nsGlobalWindow.cpp
@@ -12820,8 +12820,8 @@ void
 nsGlobalWindow::EnableOrientationChangeListener()
 {
   MOZ_ASSERT(IsInnerWindow());
-
-  if (!mOrientationChangeObserver) {
+  if (!nsContentUtils::ShouldResistFingerprinting(mDocShell)
+      && !mOrientationChangeObserver) {
     mOrientationChangeObserver =
       new WindowOrientationObserver(this);
   }
@@ -13671,7 +13671,8 @@ nsGlobalWindow::IsModalContentWindow(JSContext* aCx, JSObject* aGlobal)
 int16_t
 nsGlobalWindow::Orientation() const
 {
-  return WindowOrientationObserver::OrientationAngle();
+  return nsContentUtils::ShouldResistFingerprinting(mDocShell) ?
+           0 : WindowOrientationObserver::OrientationAngle();
 }
 #endif
 
diff --git a/dom/base/nsScreen.cpp b/dom/base/nsScreen.cpp
index ad1642b..49c12eb 100644
--- a/dom/base/nsScreen.cpp
+++ b/dom/base/nsScreen.cpp
@@ -166,25 +166,21 @@ nsScreen::Orientation() const
 void
 nsScreen::GetMozOrientation(nsString& aOrientation) const
 {
-  if (ShouldResistFingerprinting()) {
+  switch (mScreenOrientation->DeviceType()) {
+  case OrientationType::Portrait_primary:
+    aOrientation.AssignLiteral("portrait-primary");
+    break;
+  case OrientationType::Portrait_secondary:
+    aOrientation.AssignLiteral("portrait-secondary");
+    break;
+  case OrientationType::Landscape_primary:
     aOrientation.AssignLiteral("landscape-primary");
-  } else {
-    switch (mScreenOrientation->DeviceType()) {
-    case OrientationType::Portrait_primary:
-      aOrientation.AssignLiteral("portrait-primary");
-      break;
-    case OrientationType::Portrait_secondary:
-      aOrientation.AssignLiteral("portrait-secondary");
-      break;
-    case OrientationType::Landscape_primary:
-      aOrientation.AssignLiteral("landscape-primary");
-      break;
-    case OrientationType::Landscape_secondary:
-      aOrientation.AssignLiteral("landscape-secondary");
-      break;
-    default:
-      MOZ_CRASH("Unacceptable screen orientation type.");
-    }
+    break;
+  case OrientationType::Landscape_secondary:
+    aOrientation.AssignLiteral("landscape-secondary");
+    break;
+  default:
+    MOZ_CRASH("Unacceptable screen orientation type.");
   }
 }
 
@@ -236,6 +232,9 @@ bool
 nsScreen::MozLockOrientation(const Sequence<nsString>& aOrientations,
                              ErrorResult& aRv)
 {
+  if (ShouldResistFingerprinting()) {
+    return false;
+  }
   ScreenOrientationInternal orientation = eScreenOrientation_None;
 
   for (uint32_t i = 0; i < aOrientations.Length(); ++i) {
@@ -283,6 +282,9 @@ nsScreen::MozLockOrientation(const Sequence<nsString>& aOrientations,
 void
 nsScreen::MozUnlockOrientation()
 {
+  if (ShouldResistFingerprinting()) {
+    return;
+  }
   UpdateDocShellOrientationLock(GetOwner(), eScreenOrientation_None);
   mScreenOrientation->UnlockDeviceOrientation();
 }