Questions about authenticating wireless connections, SSH keys, or passwords in Ubuntu.

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135
votes
12answers
162k views

How can I set up password-less SSH login?

I want to be able to login to a remote via ssh without having to enter the password all the time. How do I set it up? Is a different command required to execute a password-less session?
103
votes
3answers
101k views

How do I deal with “unauthenticated sources” errors in the Software Center?

Any install that I'm trying through the Software Center is telling me: Requires installation of untrusted packages: The action would require the installation of packages from not authenticated ...
111
votes
6answers
77k views

Why am I getting authentication errors for packages from an Ubuntu repository?

I'm experimenting with VPNs, so I wanted to install pptpd. john@desktop:~$ sudo apt-get install pptpd [sudo] password for john: <snip> The following extra packages will be installed: bcrelay ...
27
votes
6answers
66k views

How to run an application using sudo without a password?

... but still be required for applications that need admin privilegies? In order to allow the following: $ apache2ctl restart httpd not running, trying to start (13)Permission denied: make_sock: ...
23
votes
6answers
46k views

“Software can't be installed or removed because the authentication service is not available. ”

I have 12.10 ubuntu and when I try to remove / install programs I get notification : Software can't be installed or removed because the authentication service is not available. (org....
7
votes
1answer
60k views

Can't SSH in as root

I'm using the default installation of openssh-server for my Ubuntu 14.04 server. I can connect through the console as root like normal, with my username and password. When I try to SSH with the same ...
14
votes
5answers
12k views

I deleted the “/etc/passwd” file and cannot log in

I was trying to change my username and also my home directory (/home/username) and my system started to crash. I deleted the passwd file but I had a backup named passwd_bkp. I tried to rename this ...
5
votes
3answers
26k views

Password not working for sudo (“Authentication failure”)

Before I mention anything further, DO NOT give me a response saying that terminal won't show password input. I'm AWARE of that. I'm typing my user password in (not a capslock issue), and for some ...
2
votes
3answers
20k views

Cannot authenticate without a password

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 ...
17
votes
1answer
11k views

Error authenticating some packages while upgrade

When I try to upgrade my ubuntu 13.04 to 13.10, it gives the following error: It was not possible to authenticate some packages. This may be a transient network problem. You may want to try again ...
2
votes
2answers
9k views

Graphical authentication works; why does sudo say my password is wrong?

I'm trying to install a theme, and when I enter the command sudo cp -r $HOME/Desktop/Overglossed /usr/share/themes the terminal asked for my sudo password which I entered, however I'm told my password ...
5
votes
4answers
13k views

Installed perfectly but password not working for login or authentication

I installed Ubuntu on an old XP machine (replaced XP with Ubuntu) and it seemed like it went well... Until I tried to download and install the suggested updates! The password I set during ...
50
votes
2answers
61k views

How can I allow SSH password authentication from only certain IP addresses?

I'd like to allow SSH password authentication from only a certain subnet. I see the option to disallow it globally in /etc/ssh/sshd_config: # Change to no to disable tunnelled clear text passwords #...
15
votes
8answers
20k views

ssh no longer allows public key authentication

My machine recently stopped accepting incoming public key authentication. I have an ubuntu 11.04 desktop that I ssh into from a windows machine. I use putty with pageant. I am able to connect but ...
11
votes
2answers
4k views

What is the least insecure way to store a password that is used by a script?

I have a Bash script that automatically authenticates with a service using my username and password. The credentials are currently stored as plain text within the script. What precautions should I ...
6
votes
2answers
11k views

Wifi only accepts passwords of 5 or 13 characters

Installed Ubuntu 13.04 and when attempting to connecting to a home wifi network, the connect button is only click-able with passwords of 5 or 13 characters. Is there a fix?
1
vote
1answer
8k views

Ubuntu 12.04 GPG error: http://archive.ubuntu.com precise Release: The following signatures were invalid: NODATA 1 NODATA 2 [duplicate]

I know this is asked often but nothing seems to work for me. Every time I try to update I get the following: sudo apt-get update Get:1 http://archive.ubuntu.com precise Release.gpg Get:2 http://ppa....
0
votes
1answer
348 views

how can i get past the authentication code stuff if i bought from a used computer vendor [closed]

i bought a computer with Ubuntu from a pawn shop not knowing that it had this OS can someone tell me how i can get past the authenticate code screen because I'm tired of getting the update stuff when ...
20
votes
14answers
108k views

Trying to do ssh authentication with key files: server refused our key

I'm trying to setup ssh authentication with key files in stead of username/password. The client is a Windows box running PuTTY and the server is a Ubuntu 12.04 LTS server. I downloaded puttygen.exe ...
23
votes
3answers
16k views

nslookup finds ip, but ping doesnt

I know this looks like all the other "can ping via ip but not dns" questions, but those didnt really help me at all. Also, having hosts files in all machines is not doable as this server will ...
14
votes
5answers
28k views

Can't complete dropbox installation from behind proxy

Problem: My PC on campus sits behind a proxy (requiring authentication) and I can't setup Dropbox. I am convinced that this is a proxy issue as I can't setup Ubuntu one either (but I don't use Ubuntu ...
7
votes
4answers
4k views

Stop asking for authentication to mount USB stick

My Ubuntu 14.04 is asking for my password to mount or unmount an USB stick. How can I change it, so that the mount is automatic and no password input is required ? This is about mounting arbitrary ...
6
votes
4answers
28k views

Ubuntu 12.04 network printing through Windows Samba server

I have to print through a Samba server sharing an HP printer. After upgrading to 12.04 I'm no longer able to get it to work. The printer is shared through a samba server and I need to provide logon ...
4
votes
2answers
11k views

Save print server authentication credentials

At my work, I print through a print server. My /etc/cups.d/client.conf file is: ServerName the.appropriate.server.location With this configuration I have to log in with a username and a password ...
3
votes
2answers
4k views

Immediately after login, my 12.04 LTS desktop asks for my password for “Authentication is required to change user data”

I have two Ubuntu 12.04 systems, one a desktop, and the other running as a NIS/NFS server (a desktop with lightdm disabled). When I login, I get the dialog (not error) "Authentication is required to ...
1
vote
2answers
9k views

Authentication for everything

I was wondering if it is possible to just disable the password authentication. It is getting tedious to install everything when I'm being asked to enter my password what feels like every two seconds.
11
votes
3answers
5k views

Security warning from Facebook in Chromium

I am terrified. Every ten minutes Chromium pops up with a tab stating: Success SECURITY WARNING: Please treat the URL above as you would your password and do not share it with anyone. Very ...
4
votes
6answers
9k views

Gnome/X logs off immediately after login — which logfiles are relevant?

I've been tinkering with fingerprint-gui as well as X/xrandr resolution settings. When I start my machine, it boots up normally. As soon as X and gnome have finished starting, it logs me off ...
4
votes
1answer
4k views

Google authenticator for the desktop

Is there a desktop application for Google authenticator (an equivalent to the phone app, not the PAM lib)?
3
votes
2answers
3k views

How do I install FreeNX server so that it works correctly?

I've tried every single possible way of installing the server now, I've read every how to available and I still can't get it to work. Please let me know in which step I do wrong. I'm using ubuntu 10....
5
votes
2answers
1k views

Where should a non-administrative user save a CA certificate?

I have a CA certificate that I use to connect to a WPA2 Enterprise wireless network. Where within my home folder should I store the .crt file? I don't see anything in the Filesystem Hierarchy ...
2
votes
1answer
9k views

Network authentication not working

I just installed Ubuntu 12.04 and Im trying to connect it to my NAS. It connects fine to folders where there are not authentication needed. However, if I try to open a password protected folder it ...
2
votes
2answers
6k views

Authentication in wireless network

I am authenticating a network using WPA2, but not working (authenticates then off) OS: Ubuntu 13.04 Wireless network card : Intel Corporation Ultimate N WiFi Link 5300 $dmesg: [ 1248.966666] wlan0: ...
2
votes
2answers
20k views

I cannot enter my password when using sudo to install Sophos AV for Linux [duplicate]

I cannot type my password as shown below. After successfully unlocking root account in Ubuntu 12.04 LTS. saintmichael@ubuntu:~$ sudo usage: sudo [-D level] -h | -K | -k | -V usage: sudo -v [-AknS] [-...
0
votes
2answers
4k views

Downloading error “Could not retrieve the required disk image ” [duplicate]

When I try to download Ubuntu 12.04 using the Windows installer (Wubi) through a proxy server which requires proxy authentication, after I choose the Ubuntu installation size, username and password, ...
26
votes
1answer
1k views

How to know if a authenticate box is real or fake?

For example, someone creates a fake Authenticate dialog to get my root password. How to know if it is real or fake?
5
votes
1answer
4k views

how to setup two factor authentication in Ubuntu for Ubuntu users using Google authenticator?

How to setup two factor authentication in Ubuntu for Ubuntu users using Google authenticator (It can also be setup for non Google accounts)?
19
votes
9answers
16k views

Access Prompt keeps asking for GMail password

A pop up keeping appearing in Ubuntu (running 12.10), asking for the password to my gmail account. The icon has a silver shield, and it is labeled Access Prompt. The actual window has an image of ...
7
votes
2answers
1k views

Authentication required to modify a printer- what's the password?

I have 12.04 and have 2 printers installed, both wirelessly over my personal network, no printer sharing. When I try to modify the printers I get a window asking for authentication (username and ...
5
votes
1answer
1k views

13.04 Packages cannot be Authenticated

I am unable to install updates because the following Packages cannot be authenticated: libudev1 libxml2 libasound2 google-chrome-stable libgudev-1.0-0 libtiff5 linux-image-3.8.0-19-generic ...
2
votes
4answers
7k views

12.04: LightDM freezes while “Logging in…” - maybe due to deactivated login sound [closed]

good morning, lightdm freezes often after I entered my passwort. It hangs exactly saying "logging in...". It's no total system breakdown though. I found out that there is already an existing bug ...
10
votes
5answers
10k views

Use different username on CUPS remote printing

I'm using CUPS to print on an enterprise network. The job gets submitted fine, but I need to submit it as another username. Now I'm jon but I need to send it as say jonallard. On the command line, ...
5
votes
2answers
3k views

Software center will not let me authorize

When trying to install a program from the software center it will ask for a password. I enter my password and the authentication window goes away and/or tells me there is a problem and the program ...
4
votes
4answers
9k views

Wireless Network Found, can't connect, repeated requests for authentication

After trawling through the internet, on forums, support websites, and through dozens upon dozens of answered questions on this site, I've not found a solution to what seems like a fairly regular ...
4
votes
2answers
5k views

Software can't be installed or removed because the authentication service is not available

I'm trying to install flash via the software center and I get this error : "Software can't be installed or removed because the authentication service is not available. (org.freedesktop.PolicyKit....
2
votes
0answers
960 views

I can log in with my password, but it's not accepted as valid for authentication

I can log in with my password just fine, but when trying to use sudo to run commands or authenticating to install software, my password does not work and my account is an administrator account. ...
1
vote
1answer
2k views

authentication method for likewise to join a domain

I installed likewise and joined my an active directory domain. I'm finding it's a bit unclear on how the default authentication works. Do I have to do any extra configuration to enable kerberos? If I ...
0
votes
1answer
664 views

Ubuntu can't update some repositories [duplicate]

Possible Duplicate: What is the easiest way to resolve apt-get BADSIG GPG errors? Why can't Ubuntu update some repositories? especially from extras.ubuntu.com, PPA Tualatrix for Ubuntu Tweak,...
0
votes
2answers
76 views

pam / ad issues with server-based application

Following the 16.04 upgrade we had some pam / ad issues which were solved based on community answers (ie lockscreen, authentication). We now have a new and critical one. We run a lot of RStudio ...
6
votes
1answer
2k views

UbuntuOne for Windows does not work - I got “Problem opening the ping_url” error

When I try to login to existing account I got "Problem opening the ping_url" error.