In my Linux laptop I've two disks:
One larger conventional HDD and a smaller but fast SSD.
On the SSD I've a small unencrypted
/boot-Partition containung kernels, initrd images and GRUB. All remaining stuff (including the Linux
/home, ...) is in two LUKS encrypted pseudo devices. These are started at boot time using entries in
/etc/crypttab. Everything works just fine.
But during booting I've to enter two passphrases to activate both LUKS container.
Since I've used the same pass phrase for both disks I'm now looking for a clever and secure way whichs allows me to start both disks by entering the passphrase only once during boot. Any ideas?
I already know that I could store the passphrase for the second disk in a keyfile on the already encrypted root filesystem on the SSD and refer to it in the
/etc/crypttab file. But I fear this keyfile might leak somehow (possibly
it might show up in the initrd images on unencrypted