Archive for January 11, 2018

Thursday, January 11, 2018

ScreenShield: SDK to Prevent Screenshots


ScreenShield is a patent-pending technology that allows you to view an app’s content on your screen but prevents you from taking a screenshot of it. If you try to take a screenshot on Confide, you will now simply capture a blank screen. ScreenShield also protects against other forms of screen capture, including iOS 11 screen recording, AirPlay screen mirroring, QuickTime screen recording as well as taking screenshots from the app switcher or by using Xcode.

We initially developed ScreenShield for Confide, but quickly realized that it could be used in a large number of apps — far more than we could build ourselves. That’s why we created ScreenShieldKit — to offer the ScreenShield technology to 3rd-party developers for use in a variety of different apps and categories.

Via John Gruber:

My best guess as to how they’re doing this is that they’re using AVPlayer and somehow using FairPlay Streaming to block screenshots and recording. (Where by “my” best guess I mean the best guess of a smart friend who poked around the Confide app bundle.) Have you ever noticed how you can’t take screenshots of streaming video content in apps like Netflix and HBO Go/Now? That’s a feature in iOS (and MacOS — try taking a screenshot of Netflix video playing in Safari) for skittish video providers who don’t want us to capture even a still frame of their precious content. I think ScreenShieldKit is somehow using this to prevent screenshots or video captures of text or images.


If I’m reading their application correctly, Confide also has also filed for a patent for a way to identify when you’re using another device to take a photo of your screen.


Please do not use FairPlay to block screen capture of non-premium video content. It’s not for your ‘secure’ messaging app.

Running Old iOS Versions

Apple Toolbox:

We were surprised to find out today that Apple is suddenly allowing users to downgrade their operating systems. If you have an older iPhone or an older iPad and were always a big fan of the older iOS and wished you had never upgraded your device, this may be your window of opportunity.


It appears that this was a mistake at Apple. The window of opportunity only lasted a few hours. They have stopped signing older iOS versions now.

Steve Troughton-Smith:

It’s a little frustrating that enabling the installation of older iOSes is a switch that Apple can [accidentally] flick at will, yet developers asked for firmware downgrades for years to set up test devices 🤷 (I know, testing is an alien concept to current Apple… 🙃)


Our Corellium Hypervisor for ARM enables us to run virtual iPhones in the cloud with game-changing features like:

  • Run any version of iOS
  • On demand thread list & kernel backtrace
  • Optional jailbreak for any version
  • Web-based debugging
  • And much more!

Did they get a special license from Apple to do this?

Tetris Entitlements

Olly Browning:

Lol at the Tetris app apparently needing:

  • The contents of your music library
  • Your music history
  • All of your photos
  • All of your videos

…to apparently deliver “higher quality advertising EXPERIENCES” to you.

See also: Reddit.

Apple Comments on AirPort’s Future

Christian Zibreg (via Matt Birchler):

As Apple started selling the first third-party Wi-Fi router in the form of Linksys’ Velop, its spokesperson provided a comment regarding the future of its own AirPort line of appliances.

In a statement to 9to5Mac, which first spotted the presence of Velop devices on Apple’s online and retail stores, Apple acknowledged that it’s still selling AirPort Wi-Fi base stations: […] Unfortunately, the cryptic comment doesn’t say whether Apple plans on keeping AirPort alive.

Tim Cook in 2009:

We believe that we need to own and control the primary technologies behind the products we make, and participate only in markets where we can make a significant contribution.

We believe in saying no to thousands of projects so that we can really focus on the few that are truly important and meaningful to us.

Previously: Apple Abandons Development of Wireless Routers.

Update (2018-01-12): Nick Heer:

A reader email reminded me that Apple took at least two months to patch their base station products to protect against a significant WiFi vulnerability. iOS and MacOS were updated within two weeks. I don’t know if the thirdhand information I have is right, of course, but the general thrust of the reports I’ve seen and moves Apple has made when it comes to their AirPort lineup strongly suggests that they’re not interested in the WiFi router market much longer.

Update (2018-01-14): David Sparks:

Remember when the Apple Airport was the best home WiFi solution? I sure do.

Sharing Links From iOS Twitter Appends Tracking Garbage to the URL

Benjamin Mayo:

There’s been a change to the official Twitter app in the last few months that affects anyone who tries to share a URL from inside the app. Using the standard activity view controller, recognised as the system share sheet, the Twitter app surreptitiously appends some query string parameters to the original URL.


If the user commits to sharing the URL without amending the link, Twitter can see that its iOS app was the origin of the engagement if that URL is posted publicly.


If you share to Bear, the string will literally contain the words ‘Bear-iPhone-Sharing-Extension’. One of the more obtuse ones I’ve seen is com.tinyspeck.chatlyio.share … but a quick Google search reveals that it represents the Slack sharing extension.

The fact that thee last component changes dynamically based on what action the user selects feels invasive if you don’t know what’s going on at the API level. Users are told that the activity share sheet is managed by Apple so instinctively it feels like being able to grab the activity type is nefarious.

App Store System Preferences Can Be Unlocked With Any Password

Joe Rossignol (Hacker News):

A bug report submitted on Open Radar this week has revealed a security flaw in the current version of macOS High Sierra that allows the App Store menu in System Preferences to be unlocked with any password.


Apple has fixed the bug in the latest beta of macOS 10.13.3, which currently remains in testing and will likely be released at some point this month. The bug doesn’t exist in macOS Sierra version 10.12.6 or earlier.


It’s worth noting that the App Store preferences are unlocked by default on administrator accounts, and given the settings in this menu aren’t overly sensitive, this bug is not nearly as serious as the earlier root vulnerability.

Michael Love:

This is damning, less in and of itself and more because the fact that it’s architecturally possible suggests that much of OSX security is a facade.

Matt Birchler:

This one event isn’t the end of the world, but this is how reputations degrade over time. Apple needs a software win soon, because it’s really just been a streak of bad news for them for months.

See also: Ryan Jones and Rene Ritchie.

Previously: High Sierra Bug Allows Root Access With Blank Password, Encrypted APFS Volume’s Password Exposed as Hint.

Update (2018-01-11): See also: Lloyd Chambers.