How I use cryptsetup and LUKS

• LUKS device configuration

  $ DEVICE=/dev/sdc
  $ MAPPING_NAME=sdc
  $ MOUNT_POINT=/mnt/my_mount_point

• Formatting a LUKS device

  $ sudo cryptsetup luksFormat --type luks2 $DEVICE
  ...
  $ sudo cryptsetup open $DEVICE $MAPPING_NAME
  Enter passphrase for /dev/sdc:
  $ sudo mkfs.ext4 /dev/mapper/$MAPPING_NAME
  $ sudo cryptsetup close $MAPPING_NAME

• Mounting a LUKS device

  $ sudo cryptsetup open $DEVICE $MAPPING_NAME
  Enter passphrase for /dev/sdc:
  $ sudo mount /dev/mapper/$MAPPING_NAME $MOUNT_POINT

• Unmounting an LUKS device

  $ sudo umount $MOUNT_POINT
  $ sudo cryptsetup close $MAPPING_NAME

• Making a LUKS header backup

  $ HEADER_BACKUP_FILE=header-backup-file
  $ sudo cryptsetup luksHeaderBackup --header-backup-file $HEADER_BACKUP_FILE $DEVICE

• Opening a LUKS device from a header backup

  sudo cryptsetup --header $HEADER_BACKUP_FILE luksOpen $DEVICE $MAPPING_NAME

• Adding a password to a LUKS device

  sudo cryptsetup luksAddKey $DEVICE

References

• https://security.stackexchange.com/questions/140948/mapping-of-encrypted-to-decrypted-blocks-in-lucks
• https://gitlab.com/cryptsetup/cryptsetup/-/wikis/FrequentlyAskedQuestions#6-backup-and-data-recovery
• https://askubuntu.com/questions/1319688/luks-how-can-i-add-more-password-slots-or-remove-change-a-password