Ubuntu (on which Pop!_OS is based) only added support for TPM disk encryption in Ubuntu 23.10, so my guess is that you’ll have to wait for Pop!_OS 24.04
Note that, as I understand it, using TPM will only protect data on your encrypted disk if it is removed from your computer. If someone steals your entire computer, the disk will be decrypted on boot.
There are plenty of ways to do TPM backed FDE on earlier Ubuntu. They’re just not officially supported. Clevis is one of the easier ways.
The disk will be decrypted on boot, but then they’ll have to contend with needing a password to log in
Removed by mod
Guess I’ll wait for COSMIC DE’s alpha release then. It should come with Pop!_OS 24.04
Why would you do this when PopOS offers LUKS1/2 disk encryption?
The TPM holds the LUKS key.
Ideally the key isn’t stored anywhere on the machine that contains the storage medium the key is for.
That is the tradeoff if one desires TPM-backed encryption. It really depends on the threat model.
If being able to boot unattended is more important than potential data leak if the server is physically compromised, then that’s what you have to do.
@hperrin @Dirk you can do this somehow and I even had it working at one point, but it was kinda a pain in the ass and I never redid it
https://glentomkowiak.medium.com/luks-with-tpm-in-ubuntu-df867cad9a1
Not necessarily?
Im pretty sure I used PopOS for 3 years with LUKS encryption with TPM disabled.
You don’t need TPM to enable LUKS. TPM allows you to store the LUKS keys in a secure enclave in order to automatically decrypt the drives on boot.
You also do not need TPM to automatically decrypt drives on boot, I have also done this on PopOS for 3 years, with TPM disabled.
Yes, and we are responding to someone asking about using it with the TPM.
Ok… so… if you have TPM… and LUKS…
You still have a scenario where the encryption key is still on your physical device, LUKS with or without TPM, or … some kind of TPM based Linux encryption solution I have never heard of?
Does Windows Secure Boot work on Linux via the TPM?
No…
Am I missing something?
Theres no point in involving TPM in securing a linux computer.
In a scenario where you’ve physically lost your computer, using TPM or not it wont matter if your pc gets into the hands of someone who can attempt to brute force the keys.
If your pc is remotely compromised to the point it has something on it that can grab your keys, it also will not matter if you are using TPM in some way.
The only practical use of full disk encryption is if your linux pc and or laptop gets stolen and falls into the hands of a non tech savvy person, and in that scenario, going through the trouble of correctly binding LUKS to TPM will have just been a waste of time.
Thus, you should probably just use LUKS and not bother routing it through TPM.
It’s not a new feature, it’s convenient and also has use cases outside of convenience (it’s also generally going to make stronger keys than any passphrase). Here is one way that has existed for years, except Ubuntu specifically patches it out: https://www.freedesktop.org/software/systemd/man/latest/systemd-cryptenroll.html
It’s not a lot of work, it’s one command and a one word update in the crypttab.
Secure boot is generally a requirement to use the TPM.
This person asked if they can make PopOS secure via TPM.
I am saying that while yes, you can, there isnt much point, because setting up LUKS to work with TPM is inconvenient, easy to fuck up, and basically offers no additional protection against all but extremely implausible security scenarios for basically everyone other than bladed server room admins worried about corporate espionage who are for some reason running bare metal PopOS on their server racks.
Like the only actual use case I can see for this is /maybe/ having a LUKS encrypted portable backup drive, but even then you can still base the encryption key in the actual main pc’s harddrive without using tpm, though at /that and only that point/ are we approaching parity between the difficulty of using or not using tpm to accomplish this.
You didn’t know you could use it 30 minutes ago. It seems like you don’t know how it’s set up, what protection it does or does not offer, what the use cases might be, nor where any vulnerabilities may be. I’m wondering why you remain actively involved in the conversation with an opinion rather than sitting back and learning something new.
It offers convenience of not putting in an encryption passphrase at every boot, with reasonable security against a lost or stolen machine that nobody can just boot up a live usb and access the data. Its end-user behavior is like every other consumer operating system.
You don’t seem to understand how TPM works at all. You cannot extract keys from the TPM, it provides protection against any attack that involves removing the hard drive from the computer it is installed in. This is not like storing an encryption key on a USB drive, as you seem to think. I recommend you actually do some reading on TPM before you attempt to talk with any authority. I don’t personally think it’s a great solution (for me, at least), but not for any of the reasons you’ve listed in your comments.
LUKS encrypted portable backup drive
You can’t use TPM-based encryption on a portable drive, that isn’t even possible. That’s exactly the point of TPM to begin with. You know, the whole Trusted Platform Module? That exists to ensure your hard drive (or whatever other use you have for the TPM) cannot boot or be read by any machine other than the one it was set up with. That’s the entire premise of establishing a root of trust. What are you on about?
Please, read about how TPM works.
TPM isn’t an encryption algorithm. TPM just holds the decryption key (in my case the LUKS decryption key) and hands it to the CPU if all checks pass for convenience. No key is stored in the storage in plaintext. TPM isn’t the most secure thing but at least its better than nothing at all.
Sure but you dont need to use TPM at all to use LUKS.
You can store the encryption key on the harddrive, in the LUKS partition layer.
Like thats the default of how LUKS works.
Im really confused why people think TPM needs to be involved in anyway when using LUKS.
Generally speaking you have to go out of your way to correctly cajole TPM v1 or v2 to actually correctly interface with LUKS.
The point is to have the system automatically unlock without the need for a boot password. This provides decent security if secure boot is enabled, but requires very little from the user. It isn’t a stopper for high threats, but a simple theft will mean the data is safe. It also ensures that if the drive is separated from the host machine, it is useless without a copy of they key. It doesn’t stop all threats, but stops a lot of them, and all of the most common.
Oh ok so the use case here is if this casual linux user asking this question has only their harddrive stolen from their pc or their laptop in their home or apartment or workplace, not their whole pc.
Mhm that seems likely.
I guess this maybe makes sense if youre running like a server room, but chances are low thats the actual context of this question.
Why would you run PopOS on a large operation’s servers?
While i am personally also not a huge fan of TPM for FDE it is still a valid use. Why? In order to access data on the disk you would still need to bypass the login screen which is non trivial. Also another use case is encrypting the drive so when you sell it or dispose of it you do not need to worry about wiping it at least once to get rid of all data.
TPM has its weaknesses but pls don’t talk down to someone who wants to use it when you do not understand his use case.
It should stop issues with full device theft as well, if done correctly, because if secure boot isn’t on and working, it will refuse to give the key. Which means, if it was setup correctly, the computer cannot be accessed without know the users name and password. This is the general accepted stack for Microsoft’s BitLocker. It becomes completely transparent to the user, but puts a decent blocker to access in cases of theft. There are ways around it like freezing RAM or packet sniffing an external TPM, but those are high level attacks.
If the TPM is not integrated in the CPU and rather a separate Chip on the MB, the communication can be easily sniffed since it’s not encrypted. See here https://youtu.be/wTl4vEednkQ?si=26A0NK-cVtP3uKgk
Shown how cheap it is i would not say it is high level.
Thx for your answer tho. I liked reading it.
Im really confused why people think TPM needs to be involved in anyway when using LUKS.
Because it’s convenient
Its not though, it requires a ton of extra work to set up, isn’t necessary, doesn’t allow you to do anything you can’t do without it.
You didn’t even know what it was how exactly do you know how much work it is to implement? Its about to be built into the Ubuntu installer.
doesn’t allow you to do anything you can’t do without it.
That’s false. It allows you to not need a password to unlock the volume at boot.
They correctly point out elsewhere that you could just store the unlock on an unencrypted portion of drive itself.
Yes, I know.
Nobody thinks it needs to be involved. They want it involved so the drive is automatically unlocked at boot, but inaccessible if someone removes it from the machine to try and bypass login (and in the future, if someone tries tampering). Especially useful in machines you want useable without being physically present.
It’s not cajoling anything, it’s a built in feature you configure, although Ubuntu currently goes out of their way to remove the support from some tools.
Again, you dont need to use TPM to have a LUKS encrypted partition unlock automatically on boot.
You can just do this via the standard drive management included with PopOS.
What? Are you drunk? You’re saying some nonsense right there.
Leaving keys accessible from any live distro. Keys in the TPM are not.
You can but I personally won’t trust TPM
This. But not because the tech is sketch. because storing keys in a TPM is a disaster waiting to happen
Did you make a backup of the key before storing it in the TPM? If not, then say goodbye to you data when the TPM fails.
