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Comment by ggm | Hacker News Reader

It would help if articles explained why software cannot interfere with the path from camera or microphone to the light. What quality of "exclave" is needed to do this, that simpler wiring and voltage checking chips can't do.

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The article is definitely light on details, but my reading is that this pertains to the orange dot painted in the menu bar or notification area when the camera/microphone is being rendered, not to any physical LEDs (which I believe iPads don't have for these components).

Since this is drawn on the screen, typically you might assume system-level malware that's able to get access to window server, compositor, etc would be able to prevent the dot from being drawn, or remove it after the fact.

It sounds as if what they're implying is that there is a dedicated function in a separate hardware chip, outside of the control of the primary application CPU, and not addressable by the system software at all, that paints the dot on the screen as an overlay after the image is rendered by the software display stack, but before it is presented to the OLED/LCD. That would make it very difficult or potentially impossible for even root/kernel-level malware to hide.

That would definitely be noteworthy. And it sounds like a very Apple thing to do -- based on some of the Asahi team's notes about their current hardware, they have an affinity for novel and intricate solutions at the hardware/platform level.

The idea is kind of obvious, but the implementation sounds quite tricky. Kudos to Apple.

It’s not a separate chip but a bit of code isolated from the main OS.

Apple's Secure Enclave utilizes a separate processor isolated from the main processor(s): https://support.apple.com/guide/security/secure-enclave-sec5...

It runs it's own microkernel-based OS to isolate individual tasks/functions to mitigate the impact of one of those tasks having exploitable bugs.

  eNclave
  eXclave

I stand corrected.

The best info I've been able to find about the architecture is https://www.df-f.com/blog/ios17 Is there more info available, yet? Might this be related to Apple's recent sponsorship of seL4--https://sel4.systems/news/#member-apple?

that's a nice guess. i think it's still more of the same, which is more likely.

interfacing with the display behind/on top of the display driver? i doubt it.

in the end the real target are repair shops. the marketing team just run with anything that smells like use privacy because it sells like hot cakes

It sounds impressive. One could argue for a physical LED tied to the power of the internal camera and microphone. But if I understand correctly, this exclave/dot will be work on external monitors (so the LED is not hidden just because you use one) and probably works with external cameras and microphones (which don't normally have their own LEDs). At least, it probably works with "normal" external cameras and microphones that one uses for zoom, etc.

Because it's not a separate "light", like you have on your external camera, or on a laptop — it lights up specific pixels on the "main" screen; without the CPU/GPU/mainOS knowing about it.

Exclaves run on the AP

What is the on-chip part of "Secure Exclave" then?

You will note that that verbiage does not appear in anything Gui says himself

I was gonna link to https://mastodon.social/@_inside/112440596781136013; but you're right, it says that "iPadOS running on M4" has "Secure Exclave"; not that "M4 has Secure Exclave".

Though I will admit I definitely misread it that way at first.

That is what 9to5Mac seems to have thought too :)

Thanks, I've edited the submission title to add "OS".

Do you have a source for this? I'm finding it difficult to find concrete information on the new Exclave.

This is all from research done by people smarter than me; not much has been published unfortunately. A good starting point for thinking about exclaves is by looking at ARM Realms or how pKVM is designed in Android.

> ARM Realms or how pKVM is designed in Android

And 2014-ish Bromium (now HP) uXen + AX, https://www.platformsecuritysummit.com/2018/speaker/pratt/

If the "Secure Exclave" is a privileged VM (alongside iPadOS VM) on a minimal bare-metal hypervisor, does that open the door to unprivileged Linux or other user VMs safely running alongside iPadOS on iPad Pro?

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