2 ms·
From reading the links, you can modify a cold volume, so that next time it's loaded and written, cryptsetup will write out the data decrypted to the disk, so th
by Macha 5y ago
From reading the links, you can modify a cold volume, so that next time it's loaded and written, cryptsetup will write out the data decrypted to the disk, so that you can access it cold a second time and the data will be decrypted.
So a legitimate user does have to decrypt it in the middle, but you don't need to control what they do or access it the same time they do.
- lvass 5y agoGreat explanation, thanks. Now I assume that, having an encrypted external LUKS2 device, if someone may have had access to it I should never decrypt it in a system with a vulnerable cryptsetup version.
- GekkePrutser 5y agoTo be fair, once you have the device in your hands you can do other nastiness as well such as loading a modified initramfs (such contains cryptsetup) that intercepts the entered key and writes it somewhere. This part of the boot system is normally not encrypted as it's the very step that asks for the passphrase. Good 'evil maid' mitigations should be sufficient here too, like encrypting at the SSD level with a boot password. However I do wonder if this bypasses secure boot checks as I doubt the Luks header is signed. That's normally an evil maid mitigation but I don't think it'll suffice here.