Cannot authenticate without a password

Question

The problem can be reproduced as follows:

When I remove the password of an administrator account, "Log In without Password", I cannot use that account to authenticate.
When I do something that requires authentication, I cannot use an admin without a password to authenticate. If I leave the password box blank without a password while choosing a non-password admin, authentication fails (in terminal or in GUI).

How to fix this problem?

I'm probably the last to understand, but... Are you asking how to create/change an account that doesn't require a password to log in but you then have a password to enter when you want to change the system with sudo, gksudo, etc? Or how to have an account that doesn't require a password to either login or to use sudo? — John S Gruber, Jun 13 '12 at 13:49
but even if there is no answer, surely that doesn't mean a duplicate should be opened? — Nanne, Jan 18 '13 at 21:41
possible duplicate of Why does Ubuntu force users to create a password upon installation? — Jorge Castro, Jan 18 '13 at 22:40
thank you so much! I wish i had seen your post two hours earlier! — , Feb 25 '14 at 19:52

score 4 · Answer 1 · edited Jun 19 '12 at 00:30

The answer, you don't. You will need to set a password in order to authenticate to do anything requiring authentication.

Unfortunately after the password has been removed you cannot even change your password as you must be able to authenticate in order to change your password in the settings / user account screen.

The fix:

Change your password using Terminal.

Click the windows key or click the dash button to go to the dashboard. In the search box type term and click on the program called terminal.
Type who am i and press enter to verify you are logged in as the user that you want to change.
Type passwd and press enter. It will then ask you what password you want to change it to. Enter your new password and press enter. Then it will ask you to enter your password again to verify. Enter your password again and then press enter. Your password will now be set and you will now be able to authenticate again by using your new password.

I think there is actually a way to do this. You can configure sudo to not prompt for a password (and that includes when it's used via its graphical frontends). I suspect you can configure PolicyKit to do the same thing, though I'm not sure (if I knew how I'd post this as another answer rather than a comment). Assuming that's configured, just disable screen-lock, enable automatic login, and make the password blank. (Normally it would be bad to have a blank password, but if sudo and PolicyKit succeed without password authentication, then that wouldn't be a problem.) — Eliah Kagan, Jun 19 '12 at 00:28

score 0 · Answer 2 · answered Jun 13 '12 at 04:27

0

Automatic login, "Login without Password," doesn't actually remove the password from your account--it simply fills it in for you when you log in. To authenticate (such as for gksu) you still type the same password you used to log in before.

answered Jun 13 '12 at 04:27

Kerrick

1,851

That's the "automatic login" option. "Login without a password" is different. – Alistair Buxton Jan 17 '13 at 21:34

score 0 · Answer 3 · edited Apr 13 '17 at 12:24

0

If you are asking how to restore the password to your account and/or add that account to the sudo user group, the answers to these other (duplicate?) questions may help.

I deleted my original user account. The new account has no password. How can I enable it?

How do I add myself back as a sudo user?

edited Apr 13 '17 at 12:24

Community

1

answered Jun 13 '12 at 06:51

irrational John

5,207

The OP's question is about how to make it so that all local authentication will work without prompting for a password--or, to put it another way, how to make it so that no local authentication is ever performed. (A proper answer to this question would have to explain how to make sudo work without a password, and PolicyKit as well.) – Eliah Kagan Jun 13 '12 at 08:50
@EliahKagan I'll take your word on it. It is hard for me to tell since the OP's question is not in the form of a question. Just two statements which describe how Ubuntu is (I assume) intended to work by design. – irrational John Jun 13 '12 at 09:00
Good point. Indeed, my interpretation may be mistaken. I do not recommend that you delete this answer (in case my interpretation is wrong or in case it's right but the OP also intended to ask for this information). – Eliah Kagan Jun 13 '12 at 09:06

Cannot authenticate without a password

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