recovering root password

rdavl · n00b Joined: 25 Jan 2006 Posts: 52

So a guy changes a root password and then forgets it.... is it possible to boot from live cd mount /etc partition and copy /etc/shadow- over /etc/shadow to recover old password?
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papal_authority · Veteran Joined: 31 Mar 2004 Posts: 1823 Location: Canada

Why don't you just edit /etc/shadow to have no password when booted from the CD and then boot up normally and change it?
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Headrush · Posted: Thu Feb 23, 2006 1:35 am Post subject:

Just start the LiveCD, mount the partition, chroot in and then CHANGE the passwd.
(If you forgot it anyways, why bother with recovering the old one, make a new one.)

yther · Posted: Thu Feb 23, 2006 2:48 am Post subject:

Both of those suggestions are good ones! I've used the first one; it's simple and effective. (Consult the man pages for passwd and shadow, and it should be pretty easy figuring out which field to zap.) When I had to do it, I edited /etc/passwd also, just to be safe; I don't know if it was absolutely necessary.

The second solution, however, is more elegant. It's harder to remember (at least for me), but doesn't involve editing anything.

I love LiveCDs! Recently I have discovered that it's a good idea to keep a few around. You never know when you'll need one, and when you need one you really need one...

avieth · Veteran Joined: 17 Sep 2004 Posts: 1945 Location: Canada

Or, there is another. When grub comes up on boot, press e, and edit the kernel line, adding the word

single

to the end of the line

This will give you a root command line when your init scripts are done. You can then type passwd to cahange it. Quick and easy.

hnat · n00b Joined: 23 Feb 2006 Posts: 3

I have the same problem, my gentoo box isn't accepting my root password any more. I booted with the live CD mounted the disks and chrooted. After that i could set a new password. But when i do the normal boot and try to 'su root' the new password isn't accepted. I tried some things like changing the password manually (i copied my user password to the root user) and to delete the password totally but all that doesn't lead to success. What could i try else? What could be wrong?

Thanks in advance for any suggestions
r. hnat

ecatmur · Posted: Thu Feb 23, 2006 1:55 pm Post subject:

Does your root password include punctuation characters? The livecd might be in the wrong keymap and you wouldn't notice.
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rdavl · n00b Joined: 25 Jan 2006 Posts: 52

Just a solution i did...

Boot from livecd, mount and chroot into disk instalation and did passwd... as Headrush have sugested...
It seems to be the easiest way to go around the problem...
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hnat · n00b Joined: 23 Feb 2006 Posts: 3

The password I choose has no punctuation characters nor any accented characters. Furthermore I tried different keymaps when starting the Live CD.

papal_authority · Veteran Joined: 31 Mar 2004 Posts: 1823 Location: Canada

hnat · n00b Joined: 23 Feb 2006 Posts: 3

Of course i have tried editing /etc/shadow manually. The problem is not to *set* a password. This works without a problem. But the password I set is not accepted. I am curious how the password check works. Which programs could be broken? What might be to repair?