RHCSA Exam objectives: Create Encrypted partitions

Create and format encrypted partition:

Create a new partition using parted:

Type command ‘parted’ in command line

#parted

This will bring up parted command line utility

Type ‘m’ for help

(parted) mkpart

Partition type? Primary/Extend : P

Filesystem Type : ext4

Start?

End?

(Parted) print    - to view all partitions

Finally format newly created partition

#mkfs.ext4 /dev/sda3

Encrypt partition with cryptsetup

#cryptsetup luksFormat /dev/sda3

Enter Key to encrypt file system:

Re-enter Key:

# cryptsetup luksOpen /dev/sda3 myvol

(Open the encrypted partition with some name, Here I used myvol)

Check the filesystem is properly opened. If it is, there would be an entry

#ls -lh /dev/mapper/

lrwxrwxrwx. 1 root root      7 Jan 31 16:43 myvol -> ../dm-2

To mount myvol automatically during boot add fstab entry

/dev/mapper/myvol /test1 ext4 defaults 1 2

To mount by UUID, run

#blkid

This will list all the filesystem with UUID

Finally and an fstab entry with UUID

UUID=”32-digit-number” /test1 ext4 defauls 1 2

More Important is to add an entry in /etc/crypttab as

myvol /dev/sda3

crypttab describes encrypted block devices that are setup during system boot

During boot, system will ask for password to mount /dev/mapper/myvol  on /test1 directory.

To setup automatic mount without password, add a key file for /dev/mapper/myvol. This has to be in /etc/crypttab as well.

#cryptsetup luksAddKey /dev/sda3 /home/test /test.txt

Enter the passphrase:  (Password which used to encrypt the filesystem/partition)

New key has been added to file /home/test/test.txt. Include this file in crypttab and next time when system reboots encrypted partition /dev/sda3 will be automatically mount to /test1 directory

#cat /etc/crypttab

myvol /dev/sda3 /home/test/test.txt

The format is,

mount_point partition_name /path/to/pasphrase/file

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