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Apple T2 Security Chip: Security Overview [pdf]

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Re: Apple T2 Security Chip: Security Overview [pdf]

#91

Post by PopsiclePete »

Dunedan wrote: post #79
thelittleone wrote: post #62

Earlier quoted context omitted.

As an example, the current gen Macbook Pro has an SSD that is soldered to the motherboard (so you obviously can't remove it and cable it up to USB via an adapter to extract data). Apple installed a port on the motherboard that their techs can use to recover data if the motherboard fails. But sure enough it didn't work with my 11 month old Macbook Pro. Moral of the story... even if Apple has a mechanism for hardware f…

The current generation of MacBook Pro doesn't have such a recovery port for the SSD anymore. The MacBook Pro 2016 and MacBook Pro 2017 had such a port, but the MacBook Pro 2018, which features the T2 chip, doesn't. As the encryption keys are located inside the T2 chip, if that chips breaks, all data on the SSD is lost.

>As the encryption keys are located inside the T2 chip, if that chips breaks, all data on the SSD is lost.

All my "valuable" stuff is on github, or google drive, or icloud photos or something-or-other. My local drive is really just a local "cache" for speed purposes.

I don't see how else you're expected to not lose sleep at night anymore.

Re: Apple T2 Security Chip: Security Overview [pdf]

#92

Post by arprocter »

ReC757 wrote: post #90
arprocter wrote: post #85

Earlier quoted context omitted.

Can confirm that the T2 MPB on my desk right now can't see a clonezilla USB stick (booting with option key) even with "No Security" and "Allow booting from external media" checked The stick boots fine on a non-T2 Mac Mini

Is it UEFI bootable? I believe thats a requirement with newer Macs.

Aha - it wanted GPT and also the 64 bit version.

Thanks for the pointer.

Re: Apple T2 Security Chip: Security Overview [pdf]

#93

Post by dargos »

hyperrail wrote: post #8

One interesting point in the discussion of UEFI secure boot: it appears there is no way to boot OSes other than Mac OS and Windows without disabling secure boot entirely. > By default, Mac computers supporting secure boot only trust content signed by Apple. However, in order to improve the security of Boot Camp installations, support for secure booting Windows is also provided. The UEFI firmware includes a copy of th…

Well the good news is that changing the startup security preference for T2-featured Macs is straight forward and easily user accessible. Via Recovery partition, it has replaced the standalone Firmware Password Utility located in the Utilities folder and is referred to as Startup Security Utility.

Default installations of MacOS do enable both the Secure Boot option "Full Security" and disable the Mac's ability to startup from external media however via this utility you can change that preference to "allow booting" for the latter and an option called "Medium Security" for the former. Medium Security would allow the Mac to startup from any previously trusted & signed OS, thus allowing the user the ability to downgrade (& without an internet connection) if needed. I can personally attest that if these T2 Macs were ever eligible for a build of MacOS, they can downgrade to it.

The real question is which users or administrators are majorly impacted by the T2 Mac's inability to boot into a network volume. From what I've heard, this is a T2 restriction that cannot be bypassed. This will fundamentally change the way ACMTs can service Macs going forward.

-About Startup Security - Apple Support: https://support.apple.com/en-us/HT208198

Off the top of my head, Macs with T2: 2017 iMac Pro/ 2018 13" MBP/ 2018 15" MBP/ Late 2018 MacBook Air/ Late 2018 Mac Mini

Re: Apple T2 Security Chip: Security Overview [pdf]

#94

Post by maccentric »

PuffinBlue wrote: post #76
saagarjha wrote: post #44

Earlier quoted context omitted.

…that's what I said?

Has this place become such a cesspit that you can't countenance the possibility I'm simply supporting your position and backing it up with evidence? Perhaps I should have added the word 'yes' as the first word. And someone felt the need to down vote a reply simply containing evidence that proves a commenter correct? I despair sometimes.

Never knew that countenance could be used like that. TIL

Re: Apple T2 Security Chip: Security Overview [pdf]

#95

Post by therein »

duxup wrote: post #31
gh02t wrote: post #30

Earlier quoted context omitted.

The description makes it sound like Apple is using a hardware interlock that I'd assume cuts power to the microphone via a MOSFET when the lid is closed. That's pretty much the same thing, just with a solid state switch instead of a mechanical contact.

That's pretty cool.

It is pretty cool indeed, however keep in mind that's just standard component in circuits to turn signals on and off. It is just a PNP or NPN transistor. Everyone makes use of it.

Re: Apple T2 Security Chip: Security Overview [pdf]

#96

Post by gh02t »

therein wrote: post #95
duxup wrote: post #31

Earlier quoted context omitted.

That's pretty cool.

It is pretty cool indeed, however keep in mind that's just standard component in circuits to turn signals on and off. It is just a PNP or NPN transistor. Everyone makes use of it.

To be clear too, I'm just speculating about that part. The only thing this document says is that "This disconnect is implemented in hardware alone, and therefore prevents any software, even with root or kernel privileges in macOS, and even the software on the T2 chip, from engaging the microphone when the lid is closed." That implies to me that they are using some form of physical interlock (probably a magnet and Hall-effect sensor), and that they use this to completely disable the microphone. The most obvious way to me to do that in this case would be to cut the power with a transistor, but in principle there are a number of other ways it could be achieved.

Re: Apple T2 Security Chip: Security Overview [pdf]

#97

Post by therein »

gh02t wrote: post #96
therein wrote: post #95

Earlier quoted context omitted.

It is pretty cool indeed, however keep in mind that's just standard component in circuits to turn signals on and off. It is just a PNP or NPN transistor. Everyone makes use of it.

To be clear too, I'm just speculating about that part. The only thing this document says is that "This disconnect is implemented in hardware alone, and therefore prevents any software, even with root or kernel privileges in macOS, and even the software on the T2 chip, from engaging the microphone when the lid is closed." That implies to me that they are using some form of physical interlock (probably a magnet and Hal…

I think it makes sense to assume they have a hall-effect sensor and a MOSFET but of course maybe they combined both in a single package.

Thinking how a hall-effect sensor works, perhaps it would be possible to embed it in a wafer with some gates and you're done.

Re: Apple T2 Security Chip: Security Overview [pdf]

#98

Post by thelittleone »

PopsiclePete wrote: post #91
Dunedan wrote: post #79

Earlier quoted context omitted.

The current generation of MacBook Pro doesn't have such a recovery port for the SSD anymore. The MacBook Pro 2016 and MacBook Pro 2017 had such a port, but the MacBook Pro 2018, which features the T2 chip, doesn't. As the encryption keys are located inside the T2 chip, if that chips breaks, all data on the SSD is lost.

>As the encryption keys are located inside the T2 chip, if that chips breaks, all data on the SSD is lost. All my "valuable" stuff is on github, or google drive, or icloud photos or something-or-other. My local drive is really just a local "cache" for speed purposes. I don't see how else you're expected to not lose sleep at night anymore.

I had been using iCloud for backup up until a DJ gig where I came to realize that upon enabling iCloud it had automatically moved all my AIFF music files to the cloud, leaving only a symlink behind. So that gig was a failure and pretty unprofessional. I disabled iCloud and a few days later kaboom, the Macbook died! I lost everything. My mistake for assuming the SSD could be removed and plugged in via an USB caddy.

Apple replaced everything except the bottom case. I picked up the laptop with 100% charge, tested it was working. I jumped on a flight home (no apple store in my country) and that night kaboom, Macbook died again! What are the odds? I hadn't plugged it in to anything. The eventually agreed to give me a brand new one.

The positive side of this experience was forcing me to use an iMac and only work from home office during specific hourse and to not be attached at the hip to my laptop. Net positive for my wife and I.

Re: Apple T2 Security Chip: Security Overview [pdf]

#99

Post by Joshie100 »

klausa wrote: post #68
dpkonofa wrote: post #36

Earlier quoted context omitted.

>seems like it won't work Are you speculating here or do you have some kind of insight?

I have a T2-equipped MacBook Pro and when in clamshell mode the input monitor for the mic is dead. Cracking it open makes it spring back to life. So yes, the microphone is disabled in clamshell mode if connected to displays.

It is for security reasons, disconnected by hardware when the lid is closed so that not even the T2 has access to it(or any hacker trying to listen in on you). Facetime camera works however, as closed lid essentially prevents it from seeing anything anyways.
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