Ubuntu – How to mount an AES-encrypted .DMG file containing a FAT12 filesystem

encryptionmount

My question says it all: on Ubuntu, is there any way to mount a .dmg file (as produced by OS X's Disk Utility) that contains an AES-encrypted, FAT12 filesystem?

I've seen sporadic advice about how to mount .dmg files containing hfsplus filesystems, so I'd have thought the fat12 (aka, "msdos") filesystem would be even easier. The closest I've come is:

mount -oloop,encryption=aes-256 -t msdos privatedmg.dmg ~/mounted

But this gives me the error ioctl: LOOP_SET_STATUS: Invalid argument. I don't know much about linux filesystem mechanics, but am eager to learn!

Best Answer

emm what's coming to my mind I can help you this way only:

If it's possible or if you're willing converting .dmg to .img hfsplus open a Terminal Ctrl + Alt +T and type:

sudo apt-get update

sudo apt-get upgrade

sudo apt-get install dmg2img

then install mountable manager, I use AcetoneISO:

sudo apt-get install acetoneiso

or Mountmanager:

sudo apt-get install mountmanager

firstly try to mount .dmg using one of these packages, if no access you can still use converting tool mentioned above.

Unlocking and mounting the disk with udiskctl

Instead, I used udisksctl, a command-line interface that interacts with the udisksd service.

Here's what worked (/dev/sdb5 is the partition on my hard disk marked as crypt-luks):

udisksctl unlock -b /dev/sdb5
udisksctl mount -b /dev/mapper/ubuntu--vg-root

After typing the first command, you'll be prompted for your encryption passphrase. Once the encrypted partition is unlocked, the second command will mount it. If that's successful, you'll end up with a message similar to this:

Mounted /dev/dm-1 at /media/dpm/e8cf82c0-f0a3-41b3-ab28-1f9d23fcfa72

From there I could access the data :)

Locking the disk with udiskctl

Unmount the device:

udisksctl unmount -b /dev/mapper/ubuntu--vg-root

You'll need to deactivate all logical volumes in the ubuntu-vg volume group first. Otherwise you'll get an error along the lines of 'Device busy' if you try to lock it (more info):

sudo lvchange -an ubuntu-vg

Then you'll be able to lock back the encrypted partition

udisksctl lock -b /dev/sdb5

Notes

The udisksctl commands are executed without sudo.
Device mapper names: the ubuntu--vg-root naming might change across Ubuntu releases (e.g. I've seen it called system-root and ubuntu-root too). An easy way to find out the name is to run the following command after unlocking the LUKS partition:

ls -la /dev/mapper

Then looking at the output of the ls command, the name you'll need will be generally the one symlinked to /dev/dm-1
Device mapper names, alternative: an alternative to the previous command is to run:

lsblk -e7

There you'll be able to see the device name mapping as a tree view. The -e 7 option is used to exclude the loop devices (ID 7) created by installed snaps from the output. Simply to have less clutter.
Logical volume names: you can run the sudo lvs command to find out the names of volume groups and logical volumes
Disks app: the GNOME Disks app does not automatically deactivate the logical volumes before locking the partition. Even if you've successfully unlocked the partition via the GUI, you will need to go to the command line and execute the sudo lvchange -an ubuntu-vg command before you can lock it from the GUI.

Ubuntu – Mount old encrypted home

I think you want ecryptfs-recover-private to "recover data from [your] encrypted home or encrypted private partitions. It is useful to run this from a LiveISO or a recovery image." It can use your old login passphrase to unwrap your ecrypfs mount passphrase and access your data.

You could also use ecryptfs-unwrap-passphrase with your old login passphrase to find out what the ecryptfs mount passphrase is directly.

Best Answer

Related Solutions

Command-Line Encryption – How to Mount Encrypted Volumes from Command Line

Unlocking and mounting the disk with udiskctl

Locking the disk with udiskctl

Notes

Ubuntu – Mount old encrypted home

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