security heads say: if you care about security, you shouldn’t be using systemd
Yah, ignore that bullshit.
this post was submitted on 20 Aug 2024
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Yeah, no kidding. The same systemd that enables the very things OP is trying to enable...
systemdboot + sbctl + systemd-cryptenroll and voila. TPM backed disk encryption with a PIN or FIDO2 token.
AFAIK this should be doable in Ubuntu, it just requires some command-line-fu.
Last I heard the Fedora installer was aiming to better support this type of thing - not so sure about Ubuntu.
K, so I'm probably oversimplifying, but almost all distros should allow you to at least encrypt /home, and although I haven't tried it myself yet, whole-disk encryption via UEFI is possible. You say your threat model is only someone trying to unlock your device, but it sounds as if you're not worried about espionage - someone gaining access to your computer and replacing the /efi boot process with something that will harvest your password when you log in. If all you're worried about is seizure and data protection, why isn't disk encryption sufficient?
If you really feel like you need TPM, Arch supports it, which means other distros do, too. Although, figuring it out for, e.g., Ubuntu of something you'll have to research; the Arch wiki is the most fantastic source of Linux documentation on the web, and much (but not all) of it can help with other distros.
I may be completely misunderstanding what problem you're encountering, but (a) disk encryption is trivial to set up on both Mint and EndeavorOS installers (the two I've used most recently), and (b) TPM certainly seems possible from the Arch wiki.
Idk if FDE is enough, what if the attacker can modify the boot code to capture the decryption keys and other stored passwords ? as far as I know this is exactly what secure boot protects against, it checks the validity of the boot code using the TPM chip, if it's already there, why don't most distros use it ? instead you'll see that secure boot is greyed out in the Bios ( which means it's not supported )
and yes, I did lock down the Bios too, with a different password
Edit: I'll check EndevourOS documentation, Mint is cool but it doesn't adobt newer standards or newer kernels ( newer kernels are just much more secure )
This sounds like a lenovo machine. Or something with a similar MOK enrollment process.
I forget the exact process, but I recall needing to reset the secureboot keys in "install mode" or something, then it would allow me to perform the MOK enrollment. If secureboot is greyed out in the BIOS it is never linux's fault. That's a manufacturer issue.
Apparently, some models of Lenovo don't even enable MOK enrolment and lock it down entirely. Meaning that you'd need to sign with Microsofts keys, not your own. The only way to do this is to be a high-up microsoft employee OR use a pre-provided SHIM from the distribution.
For that case, Ubuntu and Fedora are better because, per the Ubuntu documentation they do this by default.
On Ubuntu, all pre-built binaries intended to be loaded as part of the boot process, with the exception of the initrd image, are signed by Canonical's UEFI certificate, which itself is implicitly trusted by being embedded in the shim loader, itself signed by Microsoft.
Once you have secureboot working on Ubuntu or Fedora, you could likely follow these steps to enable TPM+PIN - https://wiki.archlinux.org/title/Systemd-cryptenroll#Trusted_Platform_Module
There might be some differences as far as kernel module loading and ensuring you're using the right tooling for your distro, but most importantly, the bones of the process are the same.
OH! And if you aren't getting the secureboot option in the installer UI, that could be due to booting the install media in "legacy" or "MBR" mode. Gotta ensure it's in UEFI mode.
EDIT: One more important bit, you'll need to be using the latest nvidia drivers with the nvidia-open modules. Otherwise you'll need to additionally sign your driver blobs and taint your kernel. Nvidia-Open is finally "default" as of the latest driver, but this might differ on a per-distro basis.
Thank you, this answer covers it all :D
I was going off what you said:
my threat model involves someone trying to physically unlock my device
This doesn't sound to me as if you're concerned about espionage - repeated, covert, root access to your computer, for the purpose of installing software to capture your keys, so that they can steal your computer and have complete access. If someone has remote root access to your computer, you're fucked, TPM or not; they'll just read what they want whenever you're logged in and using your computer.
TPM is for when you might not have secured physical access to your computer. Like, you're worried the NSA is going to sneak into your house while you're out shopping, pull your HD, replace the boot loader, and re-install it before you get home.
If you're only worried about, say, losing a laptop, or a search & seizure at your house, an encrypted HD is good enough. TPM and a keylocked BIOS are belts-and-suspenders, but if they want to get at the data they'll just pull the HD and run code-breaking software on it on and entirely different super-computer. TPM won't help you at all in that case.
Honestly, TPM is for a specific threat mode, which is much more like ongoing espionage, than simple opportunity theft. Your stated use case sounds more like the latter than the former.
but if they want to get at the data they'll just pull the HD and run code-breaking software on it on and entirely different super-computer. TPM won't help you at all in that case.
You make it sound so easy and doable, but the reality is that without meeting certain conditions such as the existence of the original TPM chip, a brute force attack will render the data irretrievable.. And even if I'm wrong in the last part, that would still be a pain in the butt for the attacker... and it'll buy me time... like you said ... belts-and-suspenders
This doesn't sound to me as if you're concerned about espionage
Because i don't have second chances, which is why I wish there's way to erase everything by entering a key combination.. somehow.. Idk.. like Android has that..
Because i don't have second chances, which is why I wish there's way to erase everything by entering a key combination.. somehow.. Idk.. like Android has that..
That triggered a memory for me. Apparently certain SSD(Samsung I heard of, not sure about others) always encrypt your data in hardware with a random key, this is done transparently to the OS and is otherwise unremarkable.
What it archives though and afaik is intended for is the possibility of easily and quickly "erasing" the disk by just overwriting that encryption key a couple times, I don’t remember if that used a special tool or something but if that is useful to you it probably wouldn’t be hard to find more info on this.
Samsung is a reasonably trustworthy company, not from US/UK, not Chinese, so if they say they have a clean implementation of this I’d trust them. Would be kinda a national security issue for them if it wasn’t seeing how Samsung is everywhere in gov an private sector in Korea.
What it archives though and afaik is intended for is the possibility of easily and quickly "erasing" the disk by just overwriting that encryption key a couple times, I don’t remember if that used a special tool or something but if that is useful to you it probably wouldn’t be hard to find more info on this.
first of, apologies for the late reply.. this reminds me of when I ( not so long ago ), used to overwrite random data into HDDs using Eraser, before selling my laptops or switching a company laptop, I hear SSDs are designed to last longer, so that practice ( of writing random data so it'll erase the sensitive data ), is "kind of" a time waste now.. but I guess it'll make it hard to retrieve that data, unless the attacker has some specialized software and hardware
Samsung is a reasonably trustworthy company, not from US/UK, not Chinese, so if they say they have a clean implementation of this I’d trust them
I wouldn't trust any company based only on their claims, they need to document ( explain how it works ), develop things in the open ( publish the firmware ), the schematics, even the CAD drawings.. like what the folks at System76 and Framework are doing..
That said, it sure sounds cool to have that level of protection, if only Samsung wasn't a shitty company already ( in my book )
Would be kinda a national security issue for them if it wasn’t seeing how Samsung is everywhere in gov an private sector in Korea.
I'm speculating here, but it wouldn't be far fetched if they designed a secure encrypted clean hardware for the government with military grade encryption as they like to call it, while the end users receives only enough encryption power to protect against normie threat actors like a spouse...etc companies have these policies where they provide a premium/quality products for businesses and governments but cheap or in many cases poorly made products to end users .. like Windows Home
I'm speculating here, but it wouldn't be far fetched if they designed a secure encrypted clean hardware for the government with military grade encryption as they like to call it, while the end users receives only enough encryption power to protect against normie threat actors like a spouse...etc companies have these policies where they provide a premium/quality products for businesses and governments but cheap or in many cases poorly made products to end users .. like Windows Home
I can see why you think that, but that is US centric thinking. South Korea probably cares a whole lot more about corporate security vs government security compared to the US. I don’t mean to say they don’t care about government secrets, but it’s different. No nukes, no Cold War against a superpower, instead a couple huge conglomerates basically keeping the entire GDP afloat.
Samsung in Korea isn’t like the Samsung we know, they built everything from cars, tanks, ships, insurances, constructions(they built the burj khalifa), pharmaceuticals etc.
There are probably a handful of conglomerates like that in South Korea and they basically built a state around them to manage their employees needs.
fair point, but like Edward Snowden once said: "perhaps the fundamental rule of technological progress: if something can be done, it probably will be done, and possibly already has been." he was talking about surveillance tech and programs.
I always enable disk encryption, but I wonder why Linux doesn't support secure boot and TPM based encryption ( I know that Ubuntu has plans for the later that's why I'm considering it rn )
There is at least one that, as of recently, offers both out of the box: OpenSUSE Aeon. In fact, TPM-based encryption is now mandatory.
It's rolling—based on OpenSUSE Tumbleweed—and atomic.
I need something that keeps things updated and adobts newer standards fast ( that's why I picked Fedora KDE in the first place ), I also use lots of graphical tools and video editing software, so I need the proprietary Nvidia drivers
This could be another point in Aeon's favor: it uses a combination of Flatpaks and Distrobox, meaning you can use software from basically any distribution you desire—including from, say, Arch's AUR.
I'll warn you ahead of time: Aeon and its developer are very opinionated. It's basically one person's idea of what makes "the best desktop Linux system," and those are Richard's words, not mine. It is also currently still in the release candidate stage.
In this [default] mode, Aeon will measure all of the following aspects of your systems integrity and store those measurements in your systems TPM:
UEFI Firmware
Secureboot state (enabled or disabled)
Partition Table
Boot loader and drivers
Kernel and initrd (including kernel cmdline parameters)When your system starts, it will compare the current state to the measurements stored in the TPM.
If they match, your system will boot.
As Default Mode establishes a strong 'chain of trust' between a more comprehensive list of key boot components, the use of Secureboot in Default Mode can be considered optional.
As Fallback Mode has no such measurements of boot components, Secureboot should be enabled. Disabling Secureboot in Fallback Mode leaves your system vulnerable to tampering, including attacks which may capture your passphrase when entered.
If secure boot isn't needed then what's stopping an attacker from USB booting and changing the tpm parameters or pulling the luks password? Actually what's stopping an attacker from USB booting even when secure boot is enabled? Or switching the Aeon kernel with one that won't do the check at all and registering that with secure boot?
A quick Google search says secure boot is not intended to protect against someone with physical access. Then why does it matter in the context of fde at all? Malware running after boot would have access to (most of the) unencrypted filesystem anyways. Edit: and if it has the privileges to modify kernel or boot loader it could do the things I wrote above too
And it's weird that there isn't a mode that uses a luks password in combination to the chain of trust. Relying on the user password for protection doesn't feel very secure since a physical attacker would have more opportunities to see it while the computer is in use than a luks password.
Oh, I never heard of this one before, it certainly meets the criteria, I read the documentation to understand it more
Dude, you're not lost. You have highly specialized requirements that the vast majority of people don't have so most people won't be able to help. But you definitely are ahead of the average Linux user here.
I'm one of the people that can't help you, but it looks like some others here have good suggestions
I'm not sure hardware-based full disk encryption counts as a "highly specialized requirement". It's enabled by default on Android, iOS, Mac and even Windows usually. It's a basic requirement for businesses.
even Windows usually
citation needed
It requires you to sign into a Microsoft account (which I assume most non-nerds do, given how hard they make it to avoid) and have hardware that supports it... But yes Windows enables full disk encryption by default now.
When you first sign in or set up a device with a Microsoft account, or work or school account, Device Encryption is turned on and a recovery key is attached to that account.
You should take a look at linux mint. I recently setup linux mint on a laptop, and it asked me to enroll a mok so that secure boot works with extra media codecs. On my pc i also installed the nvidia drivers pretty easily. Also mint is a ubuntu derivate, but snaps are disabled by default. Its not as fast as rolling release distros, but if you install the lastest mint version, you get the packages of the latest ubuntu lts version.
Arch Linux is a good choice. You can do most of everything you mention, only downside is you will have to set it up yourself. Provided you read the Arch Wiki, it should not be a difficult task.
Arch now also has a convenient install script, that does all the heavy lifting. It's an easy-to-use terminal interface, and basically works like any other OS installer.
I recently installed Bazzite, which is based on fedora. And it can come with Nvidia drivers, and kde. Pretty smooth in all honesty, but it is gaming focused so comes with some gaming stuff preinstalled
TPMs can be extracted with physical access
You could use a security key
TPMs can be extracted with physical access
Sure, but IIRC, they'd still need my PIN (for TPM+PIN through cryptenroll). I don't think it's possible to do TPM backed encryption without a PIN on Linux.
EDIT: Oh wait, you can... Why anyone would is beyond me though.
use something like Gentoo or Alpine… yeah but do you expect me to compile my software after ? hell no
There are more systemd-free distros like Artix Linux (which is just Arch without systemd), Devuan (which is the same thing but for Debian) and Void Linux. Btw Alpine doesn't require you to compile anything.
I heard from people who have tried both Void and Alpine, that Void is much more easier to use as a desktop OS while Alpine is more suited as a server OS..
I agree, I primarily use Alpine on servers myself
Listening to this podcast might be helpful along with the links in the show notes: https://linuxunplugged.com/572
Here's another option: https://fedoramagazine.org/automatically-decrypt-your-disk-using-tpm2/
I found these on a hacker news comment: https://fedoramagazine.org/automatically-decrypt-your-disk-using-tpm2/