Decrypting Bitlocker partiiton

Ask Fedora
1

I just installed Fedora 35 alongside Windows 11 and am trying to mount the “C:” drive that on Linux is /dev/nvmen10p3. I’m trying with Disks and it asks for the passphrase which I don’t have. I do have the recovery code though and this is what I was using on my previous Linux distro with dislocker.

I want to mount this partition when the system boots and in the past I had used two entries in fstab to achieve this. However, if I’m not able to decrypt manually, I doubt it will be possible to do so from fstab.

I’m trying to run the following command:

sudo dislocker /dev/nvme0n1p3 -pxxxxxx-xxxxxx-xxxxxx-xxxxxx-xxxxxx-xxxxxx-xxxxxx-xxxxxx -- /mnt/OS

but I’m getting the following error:

[CRITICAL] No BitLocker volume path given. Abort.
free(): double free detected in tcache 2
Aborted

I’m sure the partition is the correct one.

Any clues on what I’m doing wrong?

2

Is the windows partition actually locked with bitlocker?

If not then you should be able to mount it with the command sudo mount -t ntfs /dev/nvme0n1p3 /mnt/OS.
That message seems to indicate that either the command line structure is incorrect or the partition is not actually locked.

I don’t use bitlocker in any form but the message seems clear.

1 Like
3

Gnome Disks shows the partition as encrypted.

4

You can use the recovery passphrase, just copy it in the passphrase entry when prompted.

You can also use cryptsetup directly with the recovery key saved in a key file (this needs to be a file with just the recovery passphrase without trailing newline, the recovery key file from Windows won’t work).

sudo cryptsetup bitlkOpen /dev/nvme0n1p3 <name> --key-file <file>

and then mount the ntfs filesystem “inside” using mount

sudo mount /dev/mapper/<name> /mnt/OS
2 Likes
5

This worked perfectly. Now I wish to make this drive mount on every boot. How do I do this? How to include this drive in fstab?

6

I tried using this guide as inspiration by creating the /etc/crypttab file and add the following line:

nvme0n1p3 /dev/disk/by-uuid/<UUID-from-blkid> /home/user/<file containing recovery key> bitlkOpen

and then adding the following line to /etc/fstab:

/dev/mapper/nvme0n1p3 /mnt/OS auto defaults

I ended up in emergency mode after rebooting with both commands stuck and had to reverse the commands.

I tried modifying the files as follows:

Windows UUID=<UUID-from-blkid> /home/user/<file containing recovery key> bitlk

and

/dev/mapper/Windows /mnt/OS auto defaults

When I tried sudo mount -a I got the following error:

mount: /mnt/OS: special device /dev/mapper/Windows does not exist.

Any ideas what am I doing wrong?

7

You can’t use UUID for BitLocker in /etc/crypttab because blkid doesn’t support parsing BitLocker UUID. You can use PARTUUID=, you can use sudo blkid -p /dev/nvme0n1p3 to get it (it’s called PART_ENTRY_UUID in blkid output). This is how it looks on my system with a BitLocker USB flash drive I use for testing:

$ sudo blkid -p /dev/sdb1
/dev/sdb1: VERSION="2" TYPE="BitLocker" USAGE="crypto" PART_ENTRY_SCHEME="dos" PART_ENTRY_UUID="b999ce8b-01" PART_ENTRY_TYPE="0x7" PART_ENTRY_NUMBER="1" PART_ENTRY_OFFSET="2048" PART_ENTRY_SIZE="204800" PART_ENTRY_DISK="8:16"

$ sudo tail -1 /etc/crypttab
bitlocker PARTUUID=b999ce8b-01 /home/vojta/bitlk-keyfile bitlk

Your /etc/fstab entry looks good, but for future testing I’d recommend adding the nofail option – without it the system won’t boot if the device doesn’t exist (it’s also handy for removable devices).

1 Like
8

Glad you got your solution, could you pick the actual comment that was the solution so others experiencing this same task can find the solution too?

9

Changing the UUID with PARTUUID solved the problem. Partition is mounting at boot. Thanks.

So in summary:

  1. Get the partition’s PARTUUID with sudo blkid -p /dev/<partition>
  2. Run sudo nano /etc/crypttab and add a line with
label PARTUUID=<your_part_uuid_here> <path_to_key_file_here> bitlk
  1. Edit /etc/fstab adding a line
/dev/mapper/label <mount_point_here>  ntfs defaults,nofail
  1. Test with sudo mount -a
10

Hi Entodo

Is your “fast startup” in windows11 ON or OFF?

11

It is off.