My prediction is that Apple will start to use attestation (device check) to lock down iMessage. The problem is that this would require a software update for older devices.
> Warning: In order to generate the “validation data”, pieces of information about the device such as its serial number, model, and disk UUID are used. This means that not all validation data can be treated equivalently: just like with Hackintoshes, the account age and “score” determine if an invalid serial can be used, or if you get the “customer code” error.
The "customer code" error is a prompt from Apple, basically an attestation failure -- you have to contact Apple Support to get your Apple ID unlocked once you've tripped the failure. Legitimate customers will breeze right through (eg, just approving your login from your legit device), but Hackintosh users use crafty means to fake their way through the process.[1]
TPM did not get key from nowhere. The key need to come from network or locally generated as long as it is not preloaded when manufacturing. And in either way, it should be possible to intercept/fake it.
Apple devices with a secure enclave have the ability to attest to their identity, and also attest that keys were generated on a secure enclave (this functionality is very locked down for privacy preservation purposes, but is certainly available to Apple). If Apple is willing to lock out any device shipped without a secure enclave (which would probably be an excessive number of Macs at the moment - the iMac only started shipping with a T2 in the 2020 model, although the iMac Pro did have a T1 earlier than that) then it's absolutely possible to restrict access to actual Apple hardware with no risk of key interception.
You can't "dump" a TPM. That's the whole point. They are designed such that the cryptographic secrets they hold (including ones loaded at manufacturing) are unrecoverable without an electron microscope and nation-state level resources (and even then, it would be extremely difficult if not impossible on modern process nodes).
> unrecoverable without an electron microscope and nation-state level resources (and even then, it would be extremely difficult if not impossible on modern process nodes).
That's... amusingly, also a thing in Chinese marketplaces, for a similar purpose.
iCloud Activation Lock, on non-cellular devices (eg, Wi-Fi only iPads), relies on the device's serial number, Wi-Fi MAC, and Bluetooth MAC addresses as the three identifiers required to clear the Activation Lock check. Via special debug cables (eg, a "DCSD cable") there are ways to write in new SysCfg data to the flash to change those variables. This can also be done to Apple Watches (pre-Series 6) with a special dock also sold on the Chinese market.
You can (sort of easily) get your hands on a "clean" serial/MACs set for under $10-15 or so on the market.
Interesting. I assume this is mostly used to "wash" stolen devices to make them appear legitimate for resale? I'm surprised Apple designed the hardware to allow this without any sort of authentication.
Apple already provides security updates to all iOS devices made in the last 5ish years at least, so it would probably take a pretty trivial number of years for them to have an update deployed to nearly all iOS devices that see active use.
I think that is how BBM worked, but I could be wrong. I'd be surprised if it is part of the over arching OS security. Sounds like something that should be in their lockdown mode at the very least.
