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Bypassing disk encryption on systems with automatic TPM2 unlock

(oddlama.org)
189 points arjvik | 2 comments | 17 Jan 25 03:00 UTC | HN request time: 0.001s | source
1. rollcat ◴[17 Jan 25 16:03 UTC] No.42739214[source]▶
When I first read about TPM-based FDE on Linux[0], I was excited that the systemd guys were finally taking a step in the right direction - BitLocker/FileVault were standard on Windows/macOS for a long time by that point. FDE should be secure by default, dead-simple to set up (e.g. a checkbox in the installer that defaults to "enabled"), and painless for everyday use.

[0]: https://0pointer.de/blog/brave-new-trusted-boot-world.html

Then I read about the implementation details[0], and it's a complex bloody mess with an unending chain of brittle steps and edge cases, that are begging for a mistake and get exploited. So here we are.

I'm convinced that "measure the kernel" into "measure the initrd" into "show login screen" is all it should take.

replies(1): >>42741112 #
2. snailmailstare ◴[17 Jan 25 17:50 UTC] No.42741112[source]▶
>> we can confuse the initrd into executing a malicious init executable.

This hash the next link method is always as flawed as the weakest link..