Hacker News Reader

Comment by exikyut | Hacker News Reader

That's AMT, provided by Intel ME.

As far as I'm concerned ME-equipped NICs should unconditionally be behind VPNs, but the AMT functionality itself is really cool. Even the 10+ year old machines that don't support VNC let you remotely hit CTRL+ALT+DEL, issue an ACPI shutdown, perform a hard reset (equivalent to hitting the reset button on 486-era boxen), etc. So basically you can do either soft or hard shutdowns or reboots. Quite granular.

I actually used the hard-reset functionality while playing around with Linux early boot on a laptop a few years ago. Rebuild initramfs (loaded via PXE), use `curl` to hit AMT reset endpoint. Very cool.

View on HN

Can it enter the password required to decrypt my LUKS partition?

Lately this has been my biggest barrier to leaving a computer fully remote.

You could use a Mainboard with an IPMI module and KVM-over-LAN functionality. This way your are able to do everything remote, including mounting isos to install a new system and ofc you could use it to enter your password for the encrypted partition.

You can embed a minimal ssh server (like dropbear or tinyssh) in your initramfs to remotely enter the passphrase. There are some guides for that online

Yes, this works. I have it set up for some servers that have encrypted hard drives.

Store the LUKS crypto key in the TPM, and make sure secure boot is used so the TPM will only reveal the key if the systems boot chain is verified.

Nope. That's dangerous, TPM keys can be sniffed on the bus: https://trmm.net/tpm-sniffing/

Is a LUKS key being sent remotely to Intel ME _not_ vulnerable to being sniffed on the LAN?

You don't need to involve ME into remote decrypting. Embed the LUKS binaries and dropbear into your initramfs, and off you go.

look into tang and clevis.

I have followed this guide: https://blog.buettner.xyz/luks-verschlusseltes-ubuntu-20-04-...

If you can fiddle around and get the VNC functionality working, then as long as you have it behind a bastion host you basically have insta-BMC.

I kneejerk-recommend a bastion host because a) Intel ME, and b) there was that all-0 password bypass a while back and uhhh yeah who knows what other "sneeze correctly and the leaf falls over" knock sequences there are.

SSH port forwarding, VPN, RPi running the remote-access AMT web UI thingy (runs on Linux, forget what it's called) behind nginx with authentication... you get the idea.

Reply on news.ycombinator.com