LM Sylvia - Changed Password, now get Password Invalid at Login

[PLML]

Hello Members,

I successfully installed LM18.3 on my Toshiba Satellite x64 with Windows 7 dual boot about a month ago, and began customising it.
At install, I accidentally specified UK Keyboard instead of the std US keyboard, and created a different password to my LM 18.1
Once logged in on 18.3, I changed the root and user passwords using Terminal to match the US Keyboard.
For example @ and " are reversed on UK compared to US, and my passwords contained both.

I was able to Login to LM 18.3 for several days, then I changed my Password(s) to be identical to my 18.1 Login Password.
Since then, I have not been able to Login to LM 18.3 I get "Password Invalid" no matter what I try. At least I still have my LM18.1 working.,

I have spent weeks going through this Forum and many helpful websites, which advise how to change the password(s) by modifying Grub, and it tells me the Password has been successfully changed. When I try to Login though, I get Password Invalid.

I can get into Grub on LM 18.3 and get to /bin/bash and have been able to change both root and user passwords. It says "successfully changed".
But I cannot Login. Password Invalid. Old password no longer works.

I did take a Timeshift backup to external hard-drive prior to the problem happening, but on the command line after modifying Grub to change password, I do not know how to mount my external USB drive to Restore the backup. I can type and start Timeshift.

While I believe I can format the drive (sda5) and re-install LM 18.3, I have put lots of effort into customisation.
I would appreciate any assistance from the LM Community to be able to get my LM 18.3 Login working again.

Thank you. PLML

[Mute Ant]

With Encryption
If encryption is involved, only the original password will unlock the data. Changing the keyboard layout can make data inaccessible by making the password impossible to type. Using the root account to change a login password does not change any password needed to unlock encrypted data. They are automatically synchronised by the GUI tools, but not from a terminal.

Without Encryption
You can set the root account to behave like the account 'mint' in the live session, with no login password at all...
passwd -d root ### Unlock the root account and switch off the password requirement.
That gives everything running in your OS access to root privileges without needing any particular keyboard layout to be active. Any user can now log in as root with a simple su command. You really really don't want the system to be like this for any longer than neccessary.

Add a new account...
adduser mint
adduser mint sudo
passwd -d mint
...so that user mint can use sudo and log in without a password.

Delete the root password and lock the account account again --phew--
passwd -dl root

[PLML]

Hi Mute Ant,

Thanks for your advice.

I tried, but cannot get into your instructions for "Without Encryption" .. got access denied.
I feel the problem is with the encrypted drive.
Unfortunately, I threw away that password when I changed the root/user passwords.

Is there a way of recovering the password ?
or is it back to square one. That is, format the drive and re-install?

Alternately, can I run Timeshift from my external drive to Restore sda9?

Thanks ... PLML

[Cosmo.]

Alternately, can I run Timeshift from my external drive to Restore sda9?

In principle yes. You can use TS from any other system, inclusive a live system (at best 18.3, where TS is already installed). All you need to do is to point in the TS settings to the partition / drive, where the TS snapshots reside. Than select in TS the snapshot you want to restore and select the command from the toolbar to restore.

I write "in principle", because I never tried this with an encrypted system.

Besides that: The password cannot get recovered, because it is nowhere stored in the system. The system stores only a hash sum of it.

[PLML]

Success !!

I Restored from Timeshift backup (I was lucky to have that), and used the original Password.
So, the encrypted drive was restored by Timeshift from my LM 18.1
LM 18.3 is up and running! Wow!

I had tried the same old password previously, that led to my Post.

Well, as they say, you learn something every day.

Thanks to Mute Ant and Cosmo.