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

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93
votes
11answers
111k 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?
83
votes
3answers
78k 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 ...
25
votes
6answers
46k 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: ...
18
votes
6answers
29k 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. ...
3
votes
1answer
19k 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 ...
5
votes
3answers
21k 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 ...
40
votes
2answers
36k 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 ...
13
votes
4answers
9k 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 ...
2
votes
3answers
16k 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 ...
0
votes
1answer
6k 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 ...
18
votes
2answers
11k 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 ...
16
votes
10answers
66k 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 ...
5
votes
4answers
9k 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 ...
2
votes
2answers
4k 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 ...
26
votes
2answers
36k 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 ...
32
votes
1answer
6k views

How can I use face-recognition to login?

I am using Ubuntu 12.04 64-bit. I am looking for a facial recognition program that I could use to log in to my account. I have heard of Pam Face Recognition, but there does not appear to be a package ...
9
votes
2answers
2k 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
1answer
5k 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?
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 ...
0
votes
1answer
229 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 ...
11
votes
4answers
23k 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 ...
13
votes
7answers
15k 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 ...
4
votes
2answers
8k 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 ...
1
vote
2answers
7k 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 ...
7
votes
3answers
12k views

How to use “apt-get” via “Http-proxy” like this?

I'm trying to use apt-get command on a network that uses a proxy, like this: We use 10.114.7.7 on port 80 as Http-proxy, and after that an authentication window comes up, asking for user name and ...
4
votes
1answer
3k 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 ...
0
votes
1answer
1k views

Bypass Authenticated HTTP Proxy :Ubuntu

Is there any way to bypass authenticated http proxy to something like 127.0.0.1:port, so that we could use it any application, simply by filling out the proxy 127.0.0.1:port (which could be used for ...
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 ...
4
votes
2answers
8k views

Authentication at CUPS web interface

When I try to perform any administrative task on CUPS web interface I get pop-up window that requires me to authenticate at CUPS. Authenticating both as root and as a my user fail, even though my user ...
2
votes
2answers
16k 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] ...
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 ...
1
vote
3answers
17k views

sudo su fails with 'Unable to change to sudoers gid :operation not permitted.' fault [closed]

I have installed ubuntu and now I want to install flex. It asks for password but when I type my password, it asks me the password for root. When I enter the password which I had specified during ...
0
votes
1answer
67 views

Download apps in ubuntu software centre

I am having a problem authenticating in Ubuntu 12.04. I have no password. I have bought my computer online. There is no password when I log in. It's showing me unsuccessful password. So I cannot ...
0
votes
2answers
837 views

Software Center prompts password of another user

I have a krb5-ldap user in an "administrators" which is added to sudoers list as follows: %administrators ALL=(ALL) ALL Now that works fine for all sudo operations. But when that user wants to ...
0
votes
0answers
14 views

How do I authenticate over a domain while doing apt-get update? [duplicate]

I am getting various 401 auth errors when trying to sudo apt-get update. I am connected to my corp vpn and have an SSH into my Ubuntu machine. How can I authenticate using my network login/pw to ...
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, ...
25
votes
2answers
17k views

How can multiple private keys be used with ssh?

I was able to setup ssh to use private/public key authentication. Now I am able to do ssh user@server1 And it logs on with the private key. Now I want to connect to another server and use a ...
25
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?
7
votes
1answer
1k 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 ...
7
votes
2answers
817 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 ...
4
votes
3answers
8k views

Retrieve Windows 8 Product Key from mainboard

My new laptop came preinstalled with Windows 8. Naively, as I am, I just formatted the harddrive and installed fine old Ubuntu. Now I want to install Windows 8 for dual boot again, but I have no DVD ...
3
votes
2answers
2k 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 ...
7
votes
2answers
28k views

Proxy authentication with terminal Ubuntu 14.04

I would like to access the internet to update files etc. from the terminal on a secured proxy network. I've already tried the following: Adding to /etc/apt/apt.conf, /etc/apt/apt.conf.d/01proxy, ...
5
votes
4answers
24k 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 ...
9
votes
5answers
6k 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, ...
7
votes
3answers
4k views

Install packages without root permissions

Would it be possible to install packages without admin rights(sudo?) on Ubuntu? It doesn't have to be system-wide, maybe a private installation within /home. I want this because I'd like to setup my ...
5
votes
1answer
981 views

Yubikey Two-factor Authentication Full-disk Encryption via LUKS

I recently acquired a Yubikey Neo - a nifty little hardware second factor authentication device. It's primarily intended for use with One Time Passwords, and the emerging U2F protocol - but since ...
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 ...