Recover root password from encrypted disk

[andy55]

Hello,

I have Debian Buster installed on our family laptop. It has encrypted disk. Some time ago I changed root password ... and forgot it.
Is there any way I can boot from pen drive (the laptop doesn't have CD drive) and mount the encrypted disk ? I remember password for encrypted disk.

[Hallvor]

This may help:

https://www.linuxquestions.org/question ... 175462850/

[sgosnell]

It depends on your situation. If you have the encryption password, it's not hard. If you don't know that, you're probably out of luck. The easiest situation is if you know the password to decrypt the filesystem, and know a user password with sudo privileges. In that case, just log in as the user and use sudo passwd to change the root password. If you can't do that, try the linked thread. If you don't know the encryption password, do a complete reinstall, because without that there is no way to do anything.

[andy55]

I know encryption password and sudo is blocked.
If cryptsetup part of standard Debian buster pen-drive image ?
Which images should I use ?

[sgosnell]

I would use the live DVD image. That's easiest. Boot to the liveDVD, unlock the encrypted drive, and change the root password.

[andy55]

@sgosnell, @Hallvor
Thank you for your help.