commit 0396e4f834a31ec0cc7b9c4b853417891a09c43c Author: Arthur Edelstein arthuredelstein@gmail.com Date: Mon Jul 27 17:17:15 2015 -0700

fixup! Bug 15646: Prevent keyboard layout fingerprinting in KeyboardEvent --- dom/events/KeyCodeConsensus.h | 9 +++++++-- dom/events/KeyboardEvent.cpp | 10 +++++++++- 2 files changed, 16 insertions(+), 3 deletions(-)

diff --git a/dom/events/KeyCodeConsensus.h b/dom/events/KeyCodeConsensus.h index 5493c36..53ec7f6 100644 --- a/dom/events/KeyCodeConsensus.h +++ b/dom/events/KeyCodeConsensus.h @@ -5,14 +5,15 @@

#include "nsString.h" #include "nsDataHashtable.h" +#include "mozilla/StaticMutex.h"

// KEY_INTERNAL is called by KEY or SHIFT. -#define KEY_INTERNAL(key, code, keyCode, shift) \ +#define KEY_INTERNAL(key, code, keyCode, shift) \ gCodes->Put(NS_LITERAL_STRING(key), NS_LITERAL_STRING(#code)); \ gKeyCodes->Put(NS_LITERAL_STRING(key), keyCode); \ gShiftStates->Put(NS_LITERAL_STRING(key), shift);

-// KEY and SHIFT Assign a consensus codeName and keyCode for the given keyName. +// KEY and SHIFT assign a consensus codeName and keyCode for the given keyName. // KEY indicates that shift is off. #define KEY(key, code, keyCode) KEY_INTERNAL(key, code, keyCode, false) // SHIFT indicates that shift is on. @@ -26,12 +27,16 @@ static nsDataHashtable<nsStringHashKey, uint32_t>* gKeyCodes; // gShiftStates provides a shift value for each keyName. static nsDataHashtable<nsStringHashKey, bool>* gShiftStates;

+static StaticMutex createKeyCodesMutex; + // Populate the global static maps gCodes, gKeCodes, gShiftStates // with their constant values. static void createKeyCodes() { if (gCodes) return;

+ StaticMutexAutoLock lock(createKeyCodesMutex); + gCodes = new nsDataHashtable<nsStringHashKey, nsString>(); gKeyCodes = new nsDataHashtable<nsStringHashKey, uint32_t>(); gShiftStates = new nsDataHashtable<nsStringHashKey, bool>(); diff --git a/dom/events/KeyboardEvent.cpp b/dom/events/KeyboardEvent.cpp index 8829b8f..76e6e39 100644 --- a/dom/events/KeyboardEvent.cpp +++ b/dom/events/KeyboardEvent.cpp @@ -46,7 +46,15 @@ NS_INTERFACE_MAP_END_INHERITING(UIEvent) bool KeyboardEvent::AltKey() { - return mEvent->AsKeyboardEvent()->IsAlt(); + bool altState = mEvent->AsKeyboardEvent()->IsAlt(); + if (ResistFingerprinting()) { + nsString keyName; + GetKey(keyName); + bool exists = gCodes->Get(keyName, nullptr); + return exists ? false : altState; + } else { + return altState; + } }

NS_IMETHODIMP