#dm-crypt

ArchLinux su FileSystem Criptato con DM-Crypt

Come promesso ad alcuni amici, in questo tutorial vedremo come Installarre ArchLinux Cifrando il nostro HardDisk utilizzando Device Mapper Crypt, o più comunemente chiamato DM-Crypt. Ovviamnete l’argomento di cifratura è assai particolare e complesso, quindi suddividerò la guida in alcuni scenari possibili, basandomi sui principali modelli di partizionamento fornendo le operazioni basilari per…

Setting-Up LUKS/dm-crypt for External USB-Drive

The following commands are used to encrypt the whole USB hard-drive. This hard-drive is assumed to be on /dev/sdc. Create one partition. One can use gparted for this. Then

cryptsetup luksFormat /dev/sdc1

luksFormat is only used once.

To make this encrypted drive available as device on /dev/mapper use

cryptsetup luksOpen /dev/sdc1 SeagatePortable

The name SeagatePortable is an arbitrary…

dd bs=1M if=/dev/zero | openssl enc -rc4 \ -K $(dd bs=1 count=16 if=/dev/random | hexdump -e '8/4 "%08x"') \ -iv 00 -bufsize 65536 | (dd bs=1 count=65536 of=/dev/null && sudo dd ibs=65536 obs=1M of=/dev/sdX)

This overwrites sdX with an RC4 stream.

It is significantly faster than using /dev/urandom (on Linux), and uses less entropy, while usually serving the same purpose (for instance, to initialize a block device for use with a crypto layer).

quick-n-dirty notes to encrypt a disk/partition with LUKS and dm-crypt

(create a partition to use; sdg1) # fdisk /dev/sdg

(load the encryption modules) # modprobe dm-crypt # modprobe aes-i586

(make a dir to store the keys; usb stick is probably better. used etc for test) # mkdir /etc/keys # dd if=/dev/urandom of=/etc/keys/sdg bs=512 count=4

(encrypt the disk/partition, open the slot, format and mount the fs) # cryptsetup -c aes-xts-plain -s 512 -v luksFormat /dev/sdg1 /etc/keys/sdg # cryptsetup -d /etc/keys/sdg luksOpen /dev/sdg1 sdg # mkfs.xfs -f /dev/mapper/sdg # mount /dev/mapper/sdg /sdg