Viewing profile — kukrimate

Why does the initrd have to keep the PCRs the same after handing off to the root filesystem anyhow? Capping off the PCRs with any arbitrary value before execing into root would sto…

It is a hardware feature, but it does basically nothing without its software in flash.... The only code that is inside the silicon is a 128K bootrom that literally just sets thing …

I have the ME11's boot ROM in a disassembler as I write this :)

Absolutely is, one of those exact attacks is being used here to bypass BootGaurd. However all pre-boot attacks I am aware of rely on writing a malicious payload to the system's SPI…

Depends on how you define "booting". While its true that the microkernel always boots, and there is one userspace process running, it's a bit more subtle than that imo. The bringup…

I wrote the deguard utility that made this possible. (The vulnerability being used was found by PT Research in 2017 however.) While yes you cannot strictly disable the ME, what rem…

> eFuses, maybe? Or a bit of battery-backed SRAM. Lots of devices have a small amount of hardened storage for e.g. encryption keys. FPGAs supporting bitstream encryption and Atmel'…

Except that was never the purpose of TPMs unlike HDCP

Is anyone here talking about survaillance?? That "attestation" in the full disk encryption case means your disk encryption key only being available to the operating system you chos…

TPMs are a cryptographic coprocessor with added platform state attestation functionality. That can for example be used locally for secure secret storage that is only available in c…

Because where do you store the CPU side private key after the exchange for future sessions? The secure storage is the TPM , but here you cannot obviously store the secret in the TP…

What you are saying is sound, and I agree it could be done. But there are multiple caveats: - How do you hide the secret so that only "legitimate" operating systems can use it for …

Well yes, but there is a difference between a signal being accessible on a PCB trace I can see with my eyes, vs it being accessible only on the inside of a 7nm silicon die. There i…

> What are your thoughts on Microsoft Pluton and Google OpenTitan as TPM alternatives/emulators? I am not familiar enough of the technical details of Pluton or OpenTitan to make a …

No. But on essentially all existing UEFI systems you can trivially overwrite the "db" keystore in flash and install anything you please. Also most (all?) UEFI systems are not locke…

Unfortunately encrypted sessions without an interactively provided secret like a PIN are no defence against attacker with physical access. You either need an interactively provided…

The PIN is the important part there, encrypted sessions (and/or EK cert verification) without PIN are not much more then obfuscation, and defeated by both the interposer attack, an…

This is my hobby C compiler project. Decided to publish the code today, as it finally compiled itself. The readme on the linked GitHub page has a bit of information on how it works…