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submitted 4 months ago* (last edited 4 months ago) by flork@lemy.lol to c/linux@lemmy.ml

I recently switched to Linux (Zorin OS) and I selected "use ZFS and encrypt" during installation. Now before I can log in it asks me "please unlock disk keystore-rpool" and I have to type in the encryption password it before I'm able to get to the login screen.

Is there a way to do this automatically like with Windows or MacOS? Zorin has biometric login which is nice but this defeats the purpose especially because the encryption password is long and tedious to type in.

Also might TPM have anything to do with this?

EDIT: Based on the responses I have to assume some of you guys live in windowless underground bunkers sealed off with concrete because door locks "aren't secure against battering rams". Normal people don't need perfect encryption they just want to add an extra hurdle or two for the crackhead who steals the PC. I assumed Linux had a system similar to what Windows or MacOS has been doing for a decade but I am apparently wrong.

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[-] Confused_Emus@lemmy.world 66 points 4 months ago

Kinda curious as to the point of drive encryption if you just want it to automatically unlock on boot.

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[-] carzian@lemmy.ml 48 points 4 months ago

It's disappointing to see so many commentors arguing against you wanting to do this. Windows has it through bitlocker which is secured via the TPM as you know. Yes it can be bypassed, but it's all about your threat level and effort into mitigating it.

I am currently using a TPM on my opensuse tumbleweed machine to auto unencrypt my drive during boot. What you want to do is possible, but not widely supported (yet). Unfortunately, the best I can do is point you to the section in the opensuse wiki that worked for me.

https://en.opensuse.org/SDB:Encrypted_root_file_system

If you scroll down on that page you'll see the section about TPM support. I don't know how well it will play with your OS. As always, back up all your files before messing with hard drive encryption. Best of luck!

[-] MangoPenguin@lemmy.blahaj.zone 11 points 4 months ago

Sums up about every thread asking how to do something on Linux, 30 different responses on how the OP is wrong and shouldn't do it that way.

[-] PainInTheAES@lemmy.world 9 points 4 months ago

To be fair there are probably many different ways to solve the problem. I'm somewhat experienced with Linux and I've attempted seeing up TPM LUKS decryption on boot. It's certainly not easy or at least wasn't when I tried. For non experienced people it's easier to just enter the password at boot and enable auto login. Then you get the security, software, ethics, or licensing debates that accompany most Linux discussions.

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[-] Ptsf@lemmy.world 39 points 4 months ago

OP, just change your encryption key to whatever you have your password as and set your login to auto login. This will give you the experience you desire as it'll decrypt the disk with your password and log you in automatically once it's decrypted, but if you lock the system (close the lid. Screen lock. Etc) you'll still get a login screen as normal. (Just keep in mind they're technically two separate passwords and will unfortunately need to be changed separately if you do change your password).

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[-] Max_P@lemmy.max-p.me 38 points 4 months ago

You ended up with full disk encryption. For most people, it's the simple option, everything is encrypted. That means the OS can't start without the key, because you're the only holder of the key. It's both dead simple, and pretty bulletproof since there's no way to access the system without the password. But as you said, not everyone wants that.

What you're asking for is an encrypted home directory. It's not that Linux can't do it, it's just not what you got. Depending on the use case you can either use TPM to unlock the root partition to boot, or not encrypt the system itself. Then when you log in, it decrypts a separate partition (or use ZFS native encryption, or use fscrypt if your filesystem supports it, or use an overlay filesystem like go-cryptfs).

So it's not that Linux doesn't support your use case but rather your distro doesn't offer it as an installation option. From there you either configure it yourself (ArchWiki is great regardless of distro), or seek out a distro that does.

Linux is not an operating system, it's just the kernel. What makes it an OS is what distros build on top of it. Linux alone is not that useful, hence the basis of the GNU+Linux memes: it's Linux, plus a lot of GNU tools to make it do useful things, plus a desktop environment and a whole bunch of other libraries and applications, plus the distro's touch tying it all together in a mostly cohesive experience.

[-] Miaou@jlai.lu 5 points 4 months ago

But I'm confused, the decryption of the home directory needs the owners secret to be entered at some point? I don't see how this solves Op's problem (which I also don't understand, you want encryption, you need to decrypt stuff at some point)

[-] Max_P@lemmy.max-p.me 9 points 4 months ago

Yes, the question is when and how.

You can enter it in the bootloader as a prerequisite to boot anything. You can also enter it at the display manager / login screen, which is a little further down the boot process.

My desktop for example can boot up to the login screen and perform its NAS and routing duties all on its own. But my user and all of my user's data is still locked at that point: the computer is usable by guests and everything but even if you manage to throw a root exploit at it, my data is completely safe. Only when I log in, either locally or remotely, my password will go through PAM which will run a script that uses my password to unlock my home directory and mount it as I'm logging in.

What changes is what is covered by the encryption, and when the key is required. My root is auto unlocked via TPM, my home is unlocked on demand as I log in to my user account.

OP's problem is they have full disk encryption so they need the password to boot up Linux at all, but they also get a second password prompt to log in when it reaches the display manager, even if it's the same password. The solution is either they configure it to auto login since you need a password for the whole OS anyway, or they automate the unlocking of the root partition and use their login password to further decrypt the home directory (or rely entirely on the system being secure that the user isn't encrypted further and it's just a password prompt, which is what I think Windows does).

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[-] gofsckyourself@lemmy.world 35 points 4 months ago

EDIT: Based on the responses I have to assume some of you guys live in windowless underground bunkers sealed off with concrete. Normal people don't need perfect encryption they just want to add an extra hurdle or two for the crackhead who steals the PC. I assumed Linux had a system similar to what Windows or MacOS has been doing for a decade but I am apparently wrong.

I am sorry you were treated like this and downvoted for just asking for help without being a jerk at all.

[-] astrsk@kbin.social 23 points 4 months ago

I was kinda annoyed at double password login when I setup my system too. So what I did was just enable automatic login for my user since I’m the only one. I just treat my disk password as my login form so I just enter one password. I still have a user password for things like sudo and other permissions handling when I’m logged in but getting into a new session is automatic on startup so it doesn’t annoy me anymore. Would that work for you?

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[-] unhinge@programming.dev 16 points 4 months ago

Assuming you want:

  1. Single password prompt instead of auto-decrypt with tpm
  2. User's files to be encrypted

There are several ways to achieve this:

  1. autologin (recommended for single user system): / is encrypted using luks or zfs native encryption and user's home needs to be unencrypted. User's password may be same as encryption password for convenience, though they still are two passwords used for different purposes.

  2. pam mount: / is unencrypted or auto-decrypted and user's home is encrypted independently from / using zfs,luks,fscrypt,etc. In this case, user's login password must be same as user's home encryption password. It's suitable for multi-user system. NOTE: It cannot be used with autologin since user's home needs to be decrypted to log in.

WARNING: For tpm usage, using secure boot is highly recommended to prevent unauthorized user from accessing key stored in tpm.

To prevent auto-decrypt with tpm, tpm-pin can be used (with autologin for requirement #1).

  1. systemd-cryptenroll with/without tpm: As far as I know it can be only used to unlock disk encrypted with luks2. It can be used without tpm with pkcs11-token (e.g. YubiKey) or fido2-device. It also uses parameter encryption while key is unsealed, so safe from key sniffing via communication bus. This is easy if secure boot is enabled and luks2 is used for encryption.

  2. clevis with tpm: It can be used in place of systemd-cryptenroll. May be used with zfs native encryption. Though I'm not sure if it uses parameter encryption (correct me).

  3. unencrypted keyfile on usb: Not sure about zfs, but you can use keyfile on a usb drive to decrypt luks containers.


NOTE: I'm not a forensic/security expert. I listed a brief overview of methods I could think of to keep user's files encrypted while providing single password till login.

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[-] GolfNovemberUniform@lemmy.ml 16 points 4 months ago* (last edited 4 months ago)

Afaik you can't. Disk encryption requires entering the password every time and it asks for it BEFORE the OS is started so you can't use biometric login either

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[-] redtree3@beehaw.org 13 points 4 months ago

I'm also a linux noob, but I thought having to unlock the encryption before getting to the actual account was part of the point. If the encryption is always already unlocked it's easier to break in.

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[-] Saff@lemmy.ml 11 points 4 months ago

Instead of encrypting the entire drive, encrypt the home folder. That way it’s unlocked when you sign in.

[-] VHS@hexbear.net 10 points 4 months ago* (last edited 4 months ago)

What it sounds like you want is only your home folder encrypted, where it decrypts seamlessly upon login. It sounds like you have encrypted OS root, which is more secure but necessarily requires a password before the system gets to the login screen.

Other than reinstalling your system, you do have the option of either making your decryption password shorter, and/or enabling auto-login after boot (if you're the computer's only user), so you'd only have to type one password instead of two.

[-] flork@lemy.lol 6 points 4 months ago* (last edited 4 months ago)

Auto-Login makes the most sense I didn't consider that. I'll just have to be careful not to log out without shutting down.

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[-] Nibodhika@lemmy.world 10 points 4 months ago

Others have given you ways of doing this, with TPM or hacking away by using the same password and auto-login. Many have told you you shouldn't, but I think no one explained why.

When the bootloader chooses the OS that OS might be on an encrypted or an unencrypted disk. If the OS is on an unencrypted disk it can be easily hacked and then all bets are off. So the only safe option is if the OS is on an encrypted disk, however to do that you need to decrypt the disk to access it. Now there are two options, either you need to provide a key for decryption (it does not need to be a password, it can be a thumb drive or fingerprint) or it happens automatically. If it happens automatically it's the same as not having encryption.

Enter TPM, which is trying to safely automatically decrypt the disk by using hardware validation. However here's the problem, the only reason you need disk encryption is to prevent against your hardware being stolen. If your hardware was stolen and you don't have disk encryption people can simply read the data. If you have disk encryption they need to decrypt the disk first. However when you use TPM or anything similar the disk gets decrypted automatically, meaning that it's almost the same as not having encryption at all.

If a hacker got a hold of your unencrypted disk they can open it on a second OS and extract the data. If they got a hold of a fully encrypted disk they are more or less screwed. But if your computer unencrypted the disk on boot all they have to do now is access the disk from your OS. There are several ways of bypassing a login, brute force it, or create new users. Not to mention possible security issues that might give the attacker access to your entire system, which is already unencrypted. Yes, having some form of encryption, even if it unencrypts automatically is better than no encryption at all, but not by much. I would argue that if you care about the data not being accessed you shouldn't have it decrypt automatically, and if you don't mind it decrypting automatically then encryption might be overkill for you.

[-] umami_wasbi@lemmy.ml 10 points 4 months ago* (last edited 4 months ago)

If you want some more convenience but don't want to give up security, you can use hardware tokens like Nitrokey with GPG.

The process would be generate a random file using dd and /dev/urandom. Set this as the key for FDE. Encrypt it using your GPG and store it on /boot. Have a helper script to ask you plugin your Nitrokey and (optional) pin to decrypt the keyfile to have root decrypted. I had read this on some blog for dm-crypt so you will need to research and adopt to your setup.

[-] Eideen@lemmy.world 10 points 4 months ago

Yes there is TPM for full disk encryption.

https://gist.github.com/orhun/02102b3af3acfdaf9a5a2164bea7c3d6#using-tpm-20

Do I had problem making swap partition work. As lockdown mode is triggered.

https://man7.org/linux/man-pages/man7/kernel_lockdown.7.html

I current only encrypted home.

[-] hperrin@lemmy.world 7 points 4 months ago

If it’s LUKS encryption, yeah, you can unlock it with the TPM. I forget how. Basically you add another key to LUKS that comes from the TPM. There are guides online.

[-] Pantherina@feddit.de 6 points 4 months ago

Thats how encryption works. Encryption with TPM protects against removing the drive and reading somewhere else, so I suppose it makes sense for most people.

Linux Distros have this option, Ubuntu has it now I think, but on the others its often manual setup.

Just search for "cryptsetup change to tpm"

[-] wispydust@sh.itjust.works 6 points 4 months ago

This reply isn't going to be helpful to OP, but thought I might add context for others passing by.

I'm using Arch Linux with LUKS encryption and gdm. As long as my user's password is the same as the LUKS password, I only ever type my password in once.

Just saying that a MacOS-like convenience is definitely possible on Linux.

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[-] init@lemmy.ml 6 points 4 months ago

If you want to do away with any protection you have with opting in to a security measure, like typing in a password, why don't you just reinstall and not select the encryption option?

Not requiring a password, or automatically entering a password to decrypt the filesystem, is essentially the same as not having encryption.

Decide which you want: Security or convenience. You cannot have both.

[-] delirious_owl@discuss.online 5 points 4 months ago

You dont want to do that.

What's the point of encrypting something without a good passphrase? It defeats the whole purpose.

[-] PainInTheAES@lemmy.world 5 points 4 months ago* (last edited 4 months ago)

The common way to do it with LUKS2 and TPM as detailed on the Arch wiki. Not sure if that'll apply at all to ZFS and Zorin though

It is less secure though. What I do is set my computer to log in on start and I set up fingerprint auth. So I only need to login once on startup with the drive decryption.

Here's a reddit post on using clevis, TPM, and ZFS to decrypt.

You should also know that if you're mobo dies so does your data.

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[-] CrabAndBroom@lemmy.ml 4 points 4 months ago

Not sure if this works with drive encryption since it comes before the OS, but could this maybe be done with a YubiKey or something like that?

That way, you can plug it in and not worry about typing the password every time, but then it's also secure if someone takes your PC? As long as you remove the key when it's off of course.

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this post was submitted on 24 Feb 2024
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