[tbb-commits] [tor-browser/tor-browser-38.3.0esr-5.5-2] Bug #17207: Hide mime types and plugins when resisting fingerprinting

[gk at torproject.org]

commit 5ea30524fbf92005f236756646beb77684cd2008
Author: Arthur Edelstein <arthuredelstein at gmail.com>
Date:   Fri Oct 16 16:09:54 2015 -0700

    Bug #17207: Hide mime types and plugins when resisting fingerprinting
---
 dom/base/nsMimeTypeArray.cpp |   19 +++++++++++++++++++
 dom/base/nsPluginArray.cpp   |   13 ++++++++++---
 2 files changed, 29 insertions(+), 3 deletions(-)

diff --git a/dom/base/nsMimeTypeArray.cpp b/dom/base/nsMimeTypeArray.cpp
index 257abf6..ee530a3 100644
--- a/dom/base/nsMimeTypeArray.cpp
+++ b/dom/base/nsMimeTypeArray.cpp
@@ -14,6 +14,7 @@
 #include "nsIMIMEInfo.h"
 #include "Navigator.h"
 #include "nsServiceManagerUtils.h"
+#include "nsContentUtils.h"
 
 using namespace mozilla;
 using namespace mozilla::dom;
@@ -39,6 +40,12 @@ nsMimeTypeArray::~nsMimeTypeArray()
 {
 }
 
+static bool
+ResistFingerprinting() {
+  return !nsContentUtils::ThreadsafeIsCallerChrome() &&
+         nsContentUtils::ResistFingerprinting();
+}
+
 JSObject*
 nsMimeTypeArray::WrapObject(JSContext* aCx)
 {
@@ -78,6 +85,10 @@ nsMimeTypeArray::IndexedGetter(uint32_t aIndex, bool &aFound)
 {
   aFound = false;
 
+  if (ResistFingerprinting()) {
+    return nullptr;
+  }
+
   EnsurePluginMimeTypes();
 
   if (aIndex >= mMimeTypes.Length()) {
@@ -108,6 +119,10 @@ nsMimeTypeArray::NamedGetter(const nsAString& aName, bool &aFound)
 {
   aFound = false;
 
+  if (ResistFingerprinting()) {
+    return nullptr;
+  }
+
   EnsurePluginMimeTypes();
 
   nsString lowerName(aName);
@@ -181,6 +196,10 @@ nsMimeTypeArray::NameIsEnumerable(const nsAString& aName)
 uint32_t
 nsMimeTypeArray::Length()
 {
+  if (ResistFingerprinting()) {
+    return 0;
+  }
+
   EnsurePluginMimeTypes();
 
   return mMimeTypes.Length();
diff --git a/dom/base/nsPluginArray.cpp b/dom/base/nsPluginArray.cpp
index 1dcd551..8f789ee 100644
--- a/dom/base/nsPluginArray.cpp
+++ b/dom/base/nsPluginArray.cpp
@@ -20,6 +20,7 @@
 #include "nsIWeakReference.h"
 #include "mozilla/Services.h"
 #include "nsIInterfaceRequestorUtils.h"
+#include "nsContentUtils.h"
 
 using namespace mozilla;
 using namespace mozilla::dom;
@@ -43,6 +44,12 @@ nsPluginArray::~nsPluginArray()
 {
 }
 
+static bool
+ResistFingerprinting() {
+  return !nsContentUtils::ThreadsafeIsCallerChrome() &&
+         nsContentUtils::ResistFingerprinting();
+}
+
 nsPIDOMWindow*
 nsPluginArray::GetParentObject() const
 {
@@ -174,7 +181,7 @@ nsPluginArray::IndexedGetter(uint32_t aIndex, bool &aFound)
 {
   aFound = false;
 
-  if (!AllowPlugins()) {
+  if (!AllowPlugins() || ResistFingerprinting()) {
     return nullptr;
   }
 
@@ -217,7 +224,7 @@ nsPluginArray::NamedGetter(const nsAString& aName, bool &aFound)
 {
   aFound = false;
 
-  if (!AllowPlugins()) {
+  if (!AllowPlugins() || ResistFingerprinting()) {
     return nullptr;
   }
 
@@ -241,7 +248,7 @@ nsPluginArray::NameIsEnumerable(const nsAString& aName)
 uint32_t
 nsPluginArray::Length()
 {
-  if (!AllowPlugins()) {
+  if (!AllowPlugins() || ResistFingerprinting()) {
     return 0;
   }