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Questions tagged [authentication]

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

772 questions
307
votes
10 answers

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?
Oxwivi
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199
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6 answers

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: The following extra packages will be installed: bcrelay The following NEW packages will be installed: bcrelay…
John
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130
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2 answers

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 #PasswordAuthentication yes Is there a way to apply…
ændrük
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120
votes
4 answers

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 sources. I did an apt-get update from the command…
b. e. hollenbeck
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81
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17 answers

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 and had it generate a key pair. In…
Forkbeard
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64
votes
3 answers

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 different key. How do set it up so ssh…
Joshua
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55
votes
3 answers

How can I use a passcode generator for authentication for remote logins?

I would like to strengthen the authentication of my SSH logins by adding another factor: a passcode generator device, or a passcode generation application on my mobile phone. The only obvious options in the default setup are a fixed password and key…
Jorge Castro
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50
votes
3 answers

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 username/password, however, I repeatedly get…
vaindil
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43
votes
6 answers

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: could not bind to address 0.0.0.0:80 no listening…
tutuca
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42
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2 answers

gvfsd-admin daemon authentication forces me to restart Ubuntu - VERY annoying!

I installed Ubuntu 20.04 on a new partition less than a week ago. I have not yet gotten all the basic stuff to work. But now, from time to time, 20.04 pops up a small window saying "Authentication is required to run gvfsd-admin daemon". But even…
Henrik R.
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42
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1 answer

Use fingerprint authentication not only for login

I'm on 18.04 and have successfully enabled fingerprint login. I would like to use my fingerprint not only to login but if possible also to: Authenticate in the terminal when I do a sudo command Authenticate in Gnome (i.e. when installing an…
Hendrik
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34
votes
1 answer

Purpose of email at the end of SSH public key

I was adding one of my public keys to the authorized_keys on one of my servers when I realized that at the end of my public SSH key there is my email: $ cat .ssh/id_rsa.pub ssh-rsa AAAA[...lots of characters...]bpL johndoe@gmail.com Why is my…
Enrique Moreno Tent
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33
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1 answer

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 for Ubuntu 12.04, and the PPA has been inactive…
Aaron Hill
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33
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6 answers

"Authentication required to refresh system repositories" in Ubuntu 19.10

If one of the users in our group tries to login to his desktop computer, he gets a popup "Authentication required to refresh system repositories". When I type in my administrator password in this popup, the popup does not disappear. It seems that…
bruschino
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29
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1 answer

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?
user3683331
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