Use this tag for questions relating to authentication mechanism (i.e. proving to the system that you are you, using passwords, keycards etc.). In general don't use this and the security tag on the same question, unless it is about the security of the authentication process.

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2answers
48 views

“SSH Virtual Kiosk”. Does “PermitEmptyPasswords yes” work? - How to make ssh user with empty password, so random users can use it?

How to make properly secure ssh account with empty password for running trusted binary? I'd like to make a kind of "virtual ssh Kiosk" for random users, while limiting "demo app" behind ssh ...
3
votes
1answer
44 views

WPA supplicant dropping/disconnecting NIC in hotel wifi

TL;DR WPA Supplicant intermittently fails on my Raspberry Pi 3 when using a USB Wifi dongle. It appears to do this when "reconnecting" to or changing access points in the hotel. WPA GUI states: ...
1
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1answer
2k views

Failed to sign CSR with the CA root key

I'm trying to implement Mutual Certificate Authentication , I have to be the CA and server at the same time , generate certificates and sign them for users. and I'm following this tutorial which is a ...
3
votes
1answer
2k views

Firefox error message when adding client certificate signed by CA

I'm getting this message when I'm trying to add a certificate to Firefox's "your certificate tab". I generated and signed it before by a server which also is a CA. Failed to decode the file. ...
4
votes
1answer
715 views

Configuring Apache to Require a Client Certificate

I want to implement mutual authentication (two - way ) with apache web server. References : 1.Failed to sign CSR with the CA root key 2.Firefox error message when adding client certificate ...
12
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2answers
24k views

Meaning of “Connection closed by xxx [preauth]” in sshd logs

We have a Windows batch script, which connects automatically to a linux server via PLINK (putty). There is NO public private key authentication, the user and the password are in the script. On our ...
11
votes
4answers
17k views

Allow user1 to “su - user2” without password

I need to allow user martin to switch to user martin-test without password su - martin-test I think this can be configured in /etc/pam.d/su. There are already some lines in that file which can be ...
-2
votes
2answers
33 views

linux + ssh login took time from one server to another

I have a central Linux server (Red Hat version 6.5), and from this server I establish SSH sessions to other servers. To one server the SSH login took around 5 seconds, while to all others it took ...
-3
votes
0answers
43 views

Permission denied when accessing SSH server

So, a little background. I'm trying to host my own git server, and I decided to use SSH to log into it. I started two days ago, trying to configure SSH, to no avail. I'm hosting the server on my home ...
13
votes
3answers
37k views

I Can't login as root with su command, but I can with SSH

How is it possible that I cannot log in as root by su root or su (I get incorrect password error), but I can log in by ssh root@localhost or ssh root@my_local_IP with the same password? I'm using ...
4
votes
2answers
379 views

Disabling ssh password authentication does not work on my debian VPS

I have a Debian 7 VPS setup. I just enabled SSH Key authentication and disabled password authentication but the disabling did not work. When I attempt to SSH into my VPS, it prompts me for my SSH Key ...
13
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4answers
949 views

Groups differ from the local ones when logging in remotely

We store our users in LDAP, alongside some groups that have meaning across different systems (organizational roles including wheel). There are also groups local to workstations, e.g. audio or video ...
1
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1answer
1k views

Apache mod_auth_kerb: “Key table entry not found”

I want to use the Apache Module "mod_auth_kerb" to implement SSO for a Webapplication. With the following config: <VirtualHost 10.5.3.200:443> #Proxy <Proxy *> Order deny,allow Allow ...
0
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0answers
41 views

Authentication required to edit Sudoers - User not listed

I made a small typo in my sudoers file, nothing a simple pkexec can't fix. The problem is that when I added my user with "adduser name" and added "name" to visudo, as well as the root and sudo ...
1
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2answers
53 views

mounting a CIFS filesystem directly or via fstab

I am encountering a problem in which mounting a remote CIFS server without an fstab entry works, but mounting through fstab does not. The following command works: $ sudo mount -t cifs ...
1
vote
1answer
25 views

The most secure Alpine SSHD Configuration

I'm experimenting with Docker's alpine image and OpenSSH. The sshd_config file that ships with alpine has everything commented out by default. I only uncomment Port 22. I assume this is the most ...
0
votes
1answer
77 views

Timeouts with authd on CentOS 7

I am currently trying to augment my mailsystem by allowing servers that received mails from me within the last ten seconds to perform ident lookups. While the needed iptables rules are working ...
2
votes
3answers
2k views

Why does sudo su work, but su does not? [duplicate]

I have tried this on Fedora and on Ubuntu. kshitiz@kshitiz:~$su su: Authentication failure kshitiz@kshitiz:~$sudo su root@kshitiz:/home/kshitiz# I am entering the same password in both the cases. ...
0
votes
1answer
27 views

Connect to a wireless network as standard user without administrator authentication Linux Mint 17.3

I'm trying to get a standard user on my laptop installed with Linux Mint 17.3 on the wireless. I can get to the internet just fine logged in with an administrator but as soon as i log in with a ...
0
votes
0answers
24 views

Email user temporary code access code when using ssh

I am looking for a way to create my own two factor authentication for ssh. After the user enters the correct login info I would like the terminal to send an email to the user that contains a code ...
1
vote
2answers
11k views

vsftp user authentication problems

I configured my ftp user's home dir to /var/www and set a password but I cannot login with ftp 127.0.0.1, it keep giving me 530 Login incorrect. Why is this? I'm sure I have typed the password right. ...
1
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0answers
33 views

How to restrict su from root to nis clients

We are using NIS services for users login for Unix accounts. We have test machines where users themselves install OS and they get root access. Users are using su from root account to NIS user accounts ...
3
votes
2answers
1k views

How to stop sudo PAM messages in auth.log for a specific user?

I am using Zabbix for monitoring my environment and zabbix_agentd executes as user zabbix one custom script every 60 seconds; it uses sudo to run this script as root. In /var/log/auth.log I see every ...
1
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0answers
24 views

Openvpn authentication fail caused by wrong system date time

I have a remote linux device connected as an openvpn client to an openvpn server over TCP, with standard certificate authentication. Unfortunately this device has lost the current system Date Time, ...
1
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0answers
50 views

how to download a private google spreadsheet from linux command-line?

I have a Google Sheets spreadsheet associated to a Google account, which is private and cannot be made public. I would like to know how to download a private google spreadsheet from the command-line ...
1
vote
2answers
915 views

Cent OS 6.6 enable Plaintext authentication on dovecot and postfix

A customer of mine wants to use gmail as their default mail client but I have rolled forward to a new CENTOS server version (6.6, ok it's not "new" new) and the dovecot and postfix settings are ...
5
votes
2answers
14k views

how do I configure my RHEL5 or RHEL6 system to use ldap for authentication?

I have root access to a RHEL6 system and I want to use the corporate ldap server where I work for user authentication. I ran authconfig-tui and checked [*] Use LDAP and left [*] Use Shadow ...
2
votes
0answers
56 views

Linux Authentication Flow (NSS -> PAM -> AD)

I am a new system administrator at an organization looking to understand the process flow of authentication in regards to how NSS, PAM and WINBIND work together. We've been having winbind related ...
1
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1answer
85 views

debian 8.2 can no longer su to root

If I try to "su root" with an incorrect password, I get the expected 'authentication failure'. If I try to with the correct password, I get 'setgid: Operation not permitted" I have tried the usual ...
0
votes
0answers
102 views

Webmin: Cannot login through nginx reverse proxy

I've created a reverse proxy for webmin through nginx to run webmin at [site domain]/webmin instead of port 10000 ([site domain]:10000). When I go to [site domain]/webmin, the login page shows up as ...
1
vote
1answer
92 views

MongoDB authentication failed?

I'm currently trying to set up a secure MongoDB database for my various applications, but whenever I try to login with a username and password, but the shell always replies with Error: Authentication ...
1
vote
1answer
13 views

Red Hat 7 GDM + NIS Only Validates First 7 Characters of Password

I've come across an interesting issue this morning. We have noticed that GDM on RHEL 7 is allowing us to log-in with only the first 7 characters of password. We can enter anything or nothing from ...
0
votes
0answers
39 views

Can a Linux server that authenticates against an Active Directory accept public/private keys for passwordless login?

I have a Linux server that authenticates users against an Active Directory. Now interactive logins require username and password and automatic login requires a keytab (Kerberos) for passwordless ...
2
votes
1answer
64 views

SSH: display warning when using (deprecated) ssh-dss key

With the 7.0 release, OpenSSH disabled ssh-dss keys. The not-so-recommended workaround is to explicitly re-add DSA key support to .ssh/config, which will eventually be dropped by a later OpenSSH ...
0
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0answers
18 views

Async or Parallel PAM Authentication

I did a long google search on PAM authentication. From various sources what i learned is There is a PAM Call stack, which loads config files from different sources. Based on order of modules,its ...
1
vote
1answer
26 views

Debian package's files authentication

I know that dpkg keeps md5sums of configuration files for each package installed, so it can tell whether they are changed or not when upgrading. Does it keep md5sums for regular (non-configuration) ...
3
votes
0answers
26 views

Changing LDAP server preference on Solaris 10

I've recently inherited a new environment running Solaris 10 and I was looking for information on how to change the LDAP server preference on an LDAP client, namely through modifying the ...
0
votes
1answer
74 views

ssh authentication and remote command output's redirection

I need to run a remote capture on a host via ssh and to authenticate twice, but the second prompt is being redirected. ssh -t user@host "sudo tcpdump -s 0 -n -w - -U -i eth0 not port 22" > ...
0
votes
0answers
16 views

Can Linux ldap users still available if ldap server is unlinked?

I have a Linux with some users have their password in /etc/shadow and other authenticate through LDAP. Is there a way to make user that have their password stored on ldap continuing to be available ...
-1
votes
1answer
26 views

Ask password in window mode after sudo or other command line operations?

Was seen in movies, that after command line operations, the password was asked in separate GUI window. From my (small) experience, password, required from command line, was always asked in command ...
3
votes
0answers
32 views

exists a “two-factor authentication” for sudo, if not how to make one anyway?

tl;dr normaly to gain root priviledges via sudo requires a special user account and the use of its passphrase as means to authetication. Due to keylogging/replay (in X.org session) attacks, I would ...
2
votes
1answer
44 views

Is it possible to have a daemon run a process as another user WITHOUT having a superuser daemon?

I'm working on a project at the moment where I have a daemon that needs to run a process as another user. I would like the daemon to not run as root if possible. However, i'm struggling to figure out ...
-1
votes
1answer
31 views

Linux + LDAP/ActiveDirectory: Can't create a private group for the user like “username:username”

My apologies first for not phrasing this question very well, because it's difficult to Google. (Try finding a Google answer with the terms "self user group" in it.) Normally, with PAM in Linux, when ...
-1
votes
2answers
108 views

MariaDB: Create and grant a new user using unix sockets plugin (passwordless)

I just installed MariaDB on Kubuntu 15.10. I am able to log in with the root user via the plugin that authenticates the user from the operating system. (This is new to me, so I am learning about it ...
0
votes
2answers
292 views

Unable to login with SSH-RSA key

This post is following this question : Authentication refused: bad ownership or modes for file /var/git/.ssh/authorized_keys . The issue as exposed there is solved (about files modes of the ...
1
vote
1answer
210 views

/private/var socket not created with postfix/dovecot sasl

I'm currently running into a problem I have with my email server. I try to setup Postfix and Dovecot with SASL authentication but I get the following error when I connect with telnet (port 25) to the ...
3
votes
2answers
696 views

Multiple PCs network centralized system authentication

(I couldn't really choose an accurate title as I don't know exactly what the feature I'm looking for is called. Sorry about that. I hope that the following lines may clear this aspect.) I own a dozen ...
2
votes
1answer
937 views

LDAP Authentication on OpenBSD

I'm trying to get an OpenBSD server to authenticate users using the same LDAP server the rest of my home network uses. While 'getent password' lists the users from the LDAP server as expected, I ...
2
votes
1answer
77 views

How to allow unauthenticated logins over ssh on FreeBSD?

I created an account ckurs on my FreeBSD 10 workstation. This account uses a custom shell-script as a login-shell that attaches the user to a tmux-session in read-only mode. I have sufficiently ...
1
vote
1answer
47 views

Apache 2.4 basic auth don't work

i have a problem with basic auth to apache 2.4, i have this line: <VirtualHost *:80> ServerAdmin email@email.com DocumentRoot /var/www/html/foo ServerName my.domain.com ...