I understand LUKs can be used to encrypt your data. But what would prevent somebody plug in a USB with and just wipe my drive?
On traditional BIOS like Lenovo, HP, Dell and even Framework you can set a supervisor password that locks the boot menu. So nobody can boot from the USB.
Coreboot is different though. I spoke with Starlabs whose computers run Coreboot, and apparently you can have the boot menu password. OTOH, Sys76’s Coreboot doesnt allow such things.
I ask because i want to libreboot my T480, but the number 1 thing i worry is unauthorized USB boot.
This one: https://libreboot.org/docs/linux/grub_hardening.html#grub-password
seems to only lock the ability to edit the grub entry freely, aka press “e” to change stuff when grub fails to boot.
You could make it about equivalent to the protections afforded by the typical BIOS password, i.e. the attacker must first disassemble your laptop to reflash the spi chip or pull the hard drive. A
grub.cfglike so would do, assuming everything in encrypted partitions:set prefix=(memdisk)/boot/grub set superusers="myuser" password_pbkdf2 myuser grub.pbkdf2.sha512.10000.<your hashed password> cryptomount -u <UUID of LUKS container> search.fs_uuid <UUID of the root filesystem under LUKS container> root cryptouuid/<UUID of LUKS container> configfile ($root)/@rootfs/boot/grub/grub.cfgAssuming you boot directly to GRUB or locked out the SeaBIOS boot device selector, then GRUB will only ever look for a boot device matching your disk’s UUID; attempting to do anything else aside from entering the LUKS passphrase will prompt for the GRUB password. You’d still have your own recovery path by pressing Esc, entering your GRUB password, and dropping to the GRUB shell. Bonus points for patching the GRUB code so it doesn’t echo the UUID of your disk.
No, it isn’t bulletproof against physical access. But yes, I had the same question you did when starting out with coreboot and this was the solution I came up with.
Nothing will prevent him from wiping your drive if he has physical access to your device.
Sure you can use stuff like Secure Boot with your own custom keys to lock it. Then noone can indeed just boot it.
Doesn’t stop that person from removing your drive and plugging it into another pc. Or from just smashing your disk to pieces.
The same goes for stuff like a bios password. With physical access you can wipe that, too. It’s just a bit more work (or requires additional tools) than just an USB stick.
In short: Yes, you can stop someone from just booting an USB stick and wipe you drive. But it doesn’t matter if he has other ways to do the same. Protection only works as a whole concept, Software won’t help you when physical security allows the device to be stolen. And seriously? Who cares if their stolen laptop is wiped, smashed or drowning on the bottom of the ocean. It’s gone anyway.
The actual protection for data is a) backups so you don’t lose them and b) encryption so nobody can read them.
Yep. Physical access is equivalent to ownership. The only reasonable thing you can do to protect against it is to prevent access. Given enough time and physical access, any system can be compromised. Encryption is the only good prevention from them reading the data, but it isn’t foolproof, and backups are the only good way to ensure you can access the data after.
Idk if libreboot is coreboot+ a specific payload.
But in edk2 which is used in dasharo you can set some UEFI boot targets and disable usb boot yes, of course also set a firmware password.
There is also HEADS which is another payload of coreboot and can use a hardware security key to need to approve boot drives. Makes most sense with very stable distros like Qubes though as you dont constantly re-sign everything
I’m not sure I follow why this would be a big concern. If your drive is encrypted the worst they can do is wipe your data, which would require restoring a backup image. A hassle but it won’t give them access to your data.
Technically you would also want to encrypt your RAM. But that’s depending on your threat model.
Reading the comments makes me wonder why BIOS passwords were even invented.
Sounds like everyone is saying its a waste of time and to never use it if the biis supports it.
BIOS boot passwords were from another era with different needs and assumptions. In controlled access environments they can still have an impact if you have a proper chassis that has locks on it preventing removal of drives. Most normal people don’t possess such business class chassis. The scenario was a business environment with security teams, other employees, supervisors and locks that while you could cut them with heavy equipment you’d be noticed doing so. In terms of preventing a team of thieves breaking in with power tools and stealing things true it never was meant to prevent that. It’s more authorization and access control within an organization. The idea being perhaps the CEO’s machine or a special machine for accessing sensitive devices would be physically locked and have such a password installed as another layer of security that couldn’t be bypassed surreptitiously.
Additionally back in the day these BIOS boot passwords were paired with chassis intrusion alarms which went off every subsequent boot if the chassis was opened thanks to a sensor and the only way to clear that alarm was logging into the BIOS with an admin password.
Your gaming computer BIOS supports neither of these nor does your gaming motherboard have a chassis intrusion connector nor does your gaming case come with support for such a device.
But it was never about preventing data destruction even in these cases. It was more preventing access and making any such access more time consuming and likely to trip alarms to allow a response including evaluation of compromise by professionals.
If you want to protect your data make backups. If you want it well protected against determined parties who want to destroy all copies and/or thieves then locate a copy off-premises. If you can’t do that at least locate a copy within a bolted down safe.
I have a t480 here. It took me about five minutes to unscrew the bottom panel, remove the ssd and replace the bottom panel like before.
Just make regular backups and practice restoring from them.
Setting a BIOS password doesn’t really do much good. Someone can just unplug the CMOS battery and the password will be cleared. Even if it was stored in flash, it could be removed by erasing it with a flash programmer and flashing a new BIOS.
There are methods to detect if a device has been tampered with and disassembled. Like glitter nail polish on the screws.
Not sure if I’m helping. But sounds this could also be a X/Y problem… The way to make sure you don’t lose data is backups, not something else. I mean your SSD could as well die. Or someone doesn’t boot something, but steals the entire device… Or plugs in an USB Zapper. Backups deal with that. And deal with disk wiping as well.
If someone has physical access to your laptop, can’t just turn it on and spill a glass of water on it?
Just here for the comments, since I know of no way to disallow booting from removable media. Although I did recently come across a modern Lenovo laptop whose BIOS simply lacked the menu entry to switch boot order, boot device and anything like that…
Edit: which isn’t a problem if you do full system encryption. You can even encrypt your boot partition. And even if an adversary dumped your system
fromto a removable media, decrypting that wouldn’t be a viable option unless they were a nation state level actor.since I know of no way to disallow booting from removable media.
newer bios’es give you the option of locking usb boot from behind a supervisor password.
– meaning that you have to give the supervisor bios password if you want to boot from usb.
Cool! 🛠️
Never used libre boot but I don’t see why it should not have a bios password like all bioses…?
Anyway if a bad actor has physical access to your laptop… Well…
