Don't allow to do screenshots

[svn2208]

Is your feature request related to a problem? Please describe. The screenshot feature of IOS should be forbidden in the app. If an attacker tries to screenshot your OTPs.

Describe the solution you'd like A IOS feature should be to not allow to do screenshots (as Netflix and others do). The screenshot is simply black.

[ink-splatters]

Btw, I remember this feature not to work consistently. I haven't checked recent iOS behaviour, so my apologies beforehand, in the case the info is not applicable to the current iOS state. Leaving it here just in case, though...

when iOS multitasking is engaged with thumb swipe, one can, before finalising their gesture by letting the thumb go, manage to make a screenshot (with another hand), which would reveal all the windows, regardless of the discussed feature.

So let's take this exact case: a user has engaged, but has not finished their gesture yet.

Carousel among other things, loads pre-cached app screens it had made beforehand for itself, e.g. to show something after phone reboot when a user engages the gesture.

However, for recent 1-2-3 apps if their processes are still active, and - for the current app, definitely: live frame buffers seem to be captured and shown.

From behaviours of some apps which do forbid making screens, I can infer this is handled by app logic via some sort of callback mechanism. Please bear with my second guesses, as I'm actually not too much of iOS dev.

Still, I almost readily can bet that a screenshot keypress event is not being sent to any app in Carousel mode.

At least this is aligned with what I witnessed some time ago and which can be described like:

it's prohibited to make the app' screenshots!
but if someone really-really wants it, then they can...

The only effective implementation of this feature, as to me, is doing it on the host's (Apple's) side and not hooking into user's code, at least for the decision making.

E.g. having a corresponding entitlement would've allowed Apple to implement the app framebuf "blackening" logic much easier, for the live framebuf case.