other users password

dngongo · 11-09-2011, 08:38 PM

After installing Fedora, I had created 2 additional users. How do I retrieve their passwords which I have forgotten.

jhwilliams · 11-09-2011, 08:42 PM

I'm not sure that you do/can. I always just reset the password with

Code:

passwd <username>

If you could, what would that say about Linux security?

(Elaboration)

The password on my Ubuntu system, for example, is stored as SHA-512. There is no plain text password. You would have to crack the SHA-512 key. /etc/shadow contains the line for my password/login:

Code:

jameson:$6$C05V0Q90$0105XDS0H000.0H0004L0A00IIQL3000Z3O0X24E000001T090000B0M07000K46Q000Z48I0L0G4008T0GB0/:15140:0:99999:7:::

Here, there are several fields delimited by the : character. The second field contains three sub-fields, itself, delimited by $. 6 indicated SHA-512, the second field is a the 'salt' and the third field is the SHA-512 sum itself. (Note: that's not actually my shadow entry, I changed it for these purposes.)

(Edit 2):

Note: You could theoretically run a brute-force cracker (John The Ripper does not support SHA-512), but if you have any recent encryption schema (SHA-512, for example), it would take an eternity. E.g. in practice, it's not possible.

akuthia · 11-09-2011, 08:43 PM

I can show you the answer, but i'd like to know what steps you've done to try to solve this yourself. I ask this, because i dont use, and never have used fedora, and i found an answer withing about half a second...

dngongo · 11-09-2011, 09:37 PM

I tried that command and got:
"only root can specify user name" what does that mean?

jhwilliams · 11-09-2011, 09:39 PM

Quote:

Originally Posted by dngongo

I tried that command and got:
"only root can specify user name" what does that mean?

It means you need to run the command as root:

Code:

sudo passwd username

Or alternately, login as root and then do

Code:

passwd username

dngongo · 11-10-2011, 10:45 PM

when I login, does it means I am logged on as root automatically?
If not not, how do I? What I really want is to remove those 2 others users and as I said, i do not remember their passwd.

fukawi1 · 11-10-2011, 11:06 PM

No you are not logged in as root by default.
When you installed fedora, and set up the user account, you would have had an option to add the user to the administrators group,jhwilliams if you did so. then use(as jhwilliams suggested):

Code:

sudo passwd $username

If you did not add the user to the administrators group use (to elaborate on jhwilliams suggestion)

Code:

su -

and enter the root password you set during install.

I think you really need to do some reading on, well Linux in general. I would suggest http://rute.2038bug.com/index.html.gz as a starting point.

Quote:

What I really want is to remove those 2 others users and as I said, i do not remember their passwd.

When posting, please ask the question you want answered. As a user can't remove themselves from a system. This has to be done by root, and has nothing to do with recovering passwords.
Read the link I mentioned above, specifically http://rute.2038bug.com/node14.html.gz for information on users and groups.