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John Lawrence Aspden
Asked: 2011-03-15 12:04:45 +0800 CST

losetup encryption not working

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I've got /dev/sdb1 encrypted and mounted as /home.

The following line is in /etc/fstab:

/dev/sdb1       /home           ext3    noauto,loop=/dev/loop6,encryption=AES128

and

#mount /home

works fine, but 

#losetup -e encryption=AES128 /dev/loop0 /dev/sdb1

which I'm sure always used to work, gives:

ioctl: LOOP_SET_STATUS: No such file or directory, requested cipher or key length (128 bits) not supported by kernel

Does anyone know why? If the mechanism for aes encryption over loopback devices has been changed, how am I supposed to fsck such a drive?

10.10

1 Answers

  1. Best Answer

    If I'm not mistaken, -e is shorthand for --encryption. Try the next command instead:

    losetup --encryption AES128 /dev/loop0 /dev/sdb1

    or:

    losetup -e AES128 /dev/loop0 /dev/sdb1

    References: 

    $ losetup --help
 -e | --encryption <type> enable data encryption with specified <name/num>

    Taken from the examples section of man losetup:

              # dd if=/dev/zero of=/file bs=1k count=100
          # losetup -e des /dev/loop0 /file
          Password:
          Init (up to 16 hex digits):
          # mkfs -t ext2 /dev/loop0 100
          # mount -t ext2 /dev/loop0 /mnt
           ...
          # umount /dev/loop0
          # losetup -d /dev/loop0
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