Authentication service cannot retrieve authentication info

joshb166 · 08-12-2009, 05:22 PM

Hi everyone,

I am fairly new to Linux and have had a few setbacks. The computer I'm using is a Dell Mini 9 with Ubuntu 8.04 (Hardy) so booting from a live CD isn't possible w/out an external CD drive.

I just changed the username in /etc/passwd using "sudo gedit" and when trying to change it in /etc/shadow as well as /etc/group, I was unable to access either because I saved /etc/passwd and the terminal was asking for a password for the new username. That's when I came upon the error "Authentication service can not retrieve authentication info". So I decided to reset the comp hoping to correct the issue.

Now, I can't even log in to Ubuntu because of the username change. I have tried booting from recovery and resetting the password using "passwd username" (the actual username that is) but, again, the authentication problem. I've tried using my old password as well as admin, user, and the username itself but to no avail.

Is there anyway to reset the password or find what it was changed to without being able to log in? Or is there a way to get into /etc/shadow and /etc/group to change the necessary information without going into the terminal after login? I assume any ideas that would involve the sudo command or any of the like aren't going to work because of the password issue.

Any help would be greatly appreciated.

-Josh

Tinkster · 08-12-2009, 05:36 PM

Hi, welcome to LQ!

I'm afraid that short of the "booting of live CD from external media" you
won't have much joy. There's an old trick you may be able to try:

on the grub-prompt edit the line for the kernel, and make it
root=<your root device> init=/bin/bash

Better get familiar with nano or vi.

The issue arose because you chose to manually change the username
in those files. The usermod command was what you needed to use.

Cheers,
Tink

joshb166 · 08-13-2009, 02:03 AM

Thanks for the response Tink. I had no idea about the usermod command. I really wanna kick myself for that one >.<

So at the grub-prompt, should I remove all of the random letters and numbers that follow the "root=" and replace it with my root device (hd0,1)? And I'm not even seeing init anywhere in the kernel.

Sorry for the ridiculous questions but I am quite a "newb" :P