author Tim Huang <>
Thu, 31 Aug 2017 11:14:14 +0800
changeset 453921 b2f55468b241f28678dc5e35e19eb3b5781a1c5c
parent 453616 690e265c684ce70ecb89355314fd1574bb421f0b
child 453994 ef04f3ad847540c876c130b7d140a960d922a024
permissions -rw-r--r--
Bug 1222285 - Part 2: Making the keyboard events of modifier keys been suppressed when 'privacy.resistFingerprinting' is true. r=arthuredelstein,masayuki This patch makes 'Shift', 'Alt', 'Contorl' and 'AltGraph' been suppressed for content when fingerprinting resistance is enabled. Chrome can still get these events. The reason behind this is that websites can still observe key combinations to tell which keyboard layout is using even we spoof the keyboardEvent.code, keyboardEvent.keyCode and modifier states. For example, the AZERTY France keyboard, the digit keys of it requires the user press the Shift key. So, it is easy to differentiate AZERTY and QWERTY keyboard by observing whether a Shift key generates its own before the digit keys. There are similar issues for 'Alt' and 'AltGraph' as well. MozReview-Commit-ID: 3CwCgvey4lK