Fellow selfhoster, do you encrypt your drives where you put data to avoid privacy problems in case of theft? If yes, how? How much does that impact performances? I selfhost (amongst other services) NextCloud where I keep my pictures, medical staff, …in short, private stuff and I know that it’s pretty difficult that a thief would steal my server, buuut, you never know! 🤷🏻♂️
Nope. This isn’t part of my threat model.
I don’t have sensitive data and stealing a drive would be inconvenient for a thief.
Yes of course, with dm-crypt (luks), very little as AES-NI is incredibly fast.
Do you insert the key/password manually every time (it’s a server, so not so many times, but could happen) you boot the server?
https://www.cyberciti.biz/security/how-to-unlock-luks-using-dropbear-ssh-keys-remotely-in-linux/
As mentioned in another comment I haven’t quite gotten it working but it should be possible to do this via SSH
Have you tried secure-erasing a disk?
Absolutely yes, I do enctypt my drives so I don’t have to ever do that again. This isn’t as critical for SSDs but it’s still a good idea. Even if you keep the key stored on the same system, securely deleting a tiny file is way easier than a whole disk.
How do you even encrypt a server so that it doesn’t require human intervention every time it goes down/restarts?
Isn’t that what a TPM could be used for?
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Files could be decrypted by the end user. The OS itself could remain unencrypted.
How do you even encrypt a server so that it doesn’t require human intervention every time it goes down/restarts?
The only time my Server goes down, is when i manually reboot it. So waiting a minute or two, to ssh into it and entering the passphrase is no inconvenience.
TPM, but it’s a pain in the ass and breaks a lot. The new version of Ubuntu should handle it better, but if you’re not on Ubuntu, that won’t help you.
TPM is a good way, Mine is setup to have encryption of / via TPM with luks so it can boot no issues, then actual sensitive data like the /home/my user is encrypted using my password and the backup system + fileserver is standard luks with password.
This setup allows for unassisted boot up of main systems (such as SSH) which let’s you sign in to manually unlock more sensative drives.
Use Clevis either with TPM or Tang (remote server) https://github.com/latchset/clevis
I keep my drives encrypted with a key currently hosted in my router hoping they wouldn’t steal that. I’m thinking of actually putting it to cloud so I can disable it remotely.
It was quite a ride to make everything work and I made a blog post explaining it so I remember what I did.
https://nowicki.io/self-hosting-lvm-raid1-with-key-over-ftp/
Interesting, thanks!
I used to until I realized that I’ve got bigger threats to worry about.
And like someone else mentioned, if I have to do data recovery for some unknown reason I want to make sure the data’s not encrypted.
Why? If you store the key in your password manager shouldn’t be a problem to mount the drive on another PC, decrypt it and save data. Or am I missing something?
Recovering data from a corrupted, encrypted drive is way trickier than from a simply corrupted drive, I imagine.
Why? What would be the problem?
P.s. Why did you link to the Anti Commercial-AI license?
Why? What would be the problem?
On linux, you’re probably using LUKS. That has a header with the keys at the beginning of each encrypted volume. If those keys (or key if you only have one) is corrupted and you don’t have a backup of that, you’re fucked.
The next problem is that data recovery tools mostly don’t support decryption. They scan regions or the entire drive for recognizable things like partition headers, partition tables, file types, etc. if those are encrypted, well…
If you are able to decrypt a partition, then it might work as it will show up like any other device in
/dev/mapper/and you could dorecovery /dev/mapper/HDD. However, I have no idea what data corruption does to encryption algorithms. If one part of what is being decrypted is faulty, what does that do to the entire thing?
This mostly comes from a lack of knowledge on my part. IIRC encryption depends on hashsums -> if you change what’s being decrypted/encrypted, the entire hashsum is incorrect and thus all the data shouldn’t be able to be decrypted. But I might be wrong - I’ll gladly be wrong on this.On linux, you’re probably using LUKS. That has a header with the keys at the beginning of each encrypted volume. If those keys (or key if you only have one) is corrupted and you don’t have a backup of that, you’re fucked.
I got it, thanks! I will rely on SnapRaid form redundancy and on backups on multiple devices/locations.
The way you recover data from a totally dead drive is use a program that scans every byte and looks for structures in the data that look like files e.g. a jpeg will have a header followed by some blocks of content. In an encrypted drive everything looks like random data.
Even if you have the key, you can’t begin searching through the data until it’s decrypted, and the kind of error that makes it so your drive won’t mount normally is likely to get in the way of decrypting normally as well.
It’s a relatively low performance hit and it benefits me when having to replace a failing/old disk. I can just toss the drive without having to erase the data first, that is as long as the key is a secure length.
I use full disk encryption for every server (and other computers).
Encrypting your data drives is a must for everyone imho. Encrypting the OS is a must for me🤷♂️
My PC weighs 80+ lbs, live 8km from town, surrounded by farm land and there are only 3,400 in town and I live 30 min from a city of 40,000 and 40 min from another city of 70,000 and my internet is 20/10 mbps
What’s your point?
FreeAin’t no one stealing my shit, even via internet to upload 40tb would take 1 year 5 days at max speed in actuality it would be 1 year 8 months… Fuck I miss my 1.5G fibre connection…
No. If someone gets to my server that’ll be the least of my worries.
In addition to “encryption at rest”, also consider that your devices might be exploited over the internet, so attackers may be able to access the decrypted state that way. To guard against that, you may wish to encrypt certain documents with an additional password, even if they are sitting on an encrypted file system.
Recall that within a month, the widely SSH was exploited and a backdoor added to every machine. I had upgraded to that SSH version. I didn’t run an SSH server on that box, but it goes to show that even those who take precautions can end up exploited!
That’s why I use most of the services via Wireguard (except Nextcloud that is behind Cloudflare and MQTTs that’s completely exposed)
On laptops yes, on my server no. Most of the data is photo backups and linux ISOs form over the years.
Yes.
My home server has dropbear-initramfs installed so that after reboot I can access the LUKS decryption prompt over SSH. The one LUKS partition contains a btrfs filesystem with both rootfs and home as subvolumes. For all the other drives attached to that system, I use ZFS native encryption with a dataset that decrypts with a keyfile from that rootfs and I have backups of an encrypted copy of that keyfile.
I don’t think there’s a substantial performance impact but I’ve never bothered benchmarking.
Yes, all, no matter what data is, it’s not hard and doesn’t have any consequences, but protects from many inconvenient accidents
I want to, but haven’t found the time to make a strategy on how to move over the data. It would take a bunch of shuffling as all drives are in use. The next problem is decrypting at boot and securely storing the decryption key - if I choose to use a decryption key at all. Maybe it’ll be a usb key that I have to plug into the server when starting it, or I have to setup decryption of the system over SSH, but that means automated restarts are… difficult.
Not sure how to tackle the problem yet…
I use separate disks for data storage and my OS. That way a headless system can boot and all the services like SSH can become available, and I can decrypt the data drives remotely.
When there’s an unexpected reboot I can still get into my system and decrypt remotely which is nice. I can also move the data storage disks to another system without too much hassle.
I did have to make sure some services were fault tolerant if an encrypted volume was unavailable when the OS booted. An example of this might be torrenting software, I needed to make sure the temporary storage was on an encrypted volume. The software had a sane fault mode when the final storage location was unavailable, but freaked out for some reason when the temp storage was missing.
Once set up the whole thing is pretty easy to manage.
I did have to make sure some services were fault tolerant if an encrypted volume was unavailable when the OS booted
How did you achieve that? systemd dependency?
I’m pretty sure I didn’t mess with systemd, though that would probably be the right way to handle it.
I was able to update a runtime config so if any storage wasn’t available it just halted the service. Then I created a short script I’d invoke manually which decrypted the luks drives and brought the dependent services up. I also added monitoring to alert me when the drives weren’t available for whatever reason.
I did have LUKS and a USB flash drive with a key to be inserted on boot. It was definitely difficult and caused performance issues. It was particularly difficult to add/remove drives from the array. These days I only encrypt my off-site backups that sit at the office where my coworkers potentially have physical access.
There have been recent advancements in TPM so disk encryption is easier to maintain and doesn’t affect performance. I’ll need to investigate this one day. My server/NAS is a 4th-gen i5, so it may not support the functions I would need. Full disk encryption will land in Ubuntu soon. I’m hanging out for that.
