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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4
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1answer
197 views

Easiest way to manage users for two machines

I'm administrating two ubuntu desktops and one debian server. There are abount ~20 active users on the desktops. A few (5-10) user accounts are added each year and about the same amount become ...
4
votes
1answer
1k views

Program to keep track number of login attempts

Is there any way to keep track of number of attempts made by a user to login into his system?
4
votes
1answer
135 views

How can I determine which SSH keyfile was used to authenticate a login?

We have a hosted CentOS 6.5 server in which we have a single user account. That account has been configured to use SSH keyfile authentication for the users who need to access it. I would like to be ...
4
votes
2answers
2k views

Git-SVN Not Allowing Me to Authenticate

Git 1.7.9.1 on Arch Linux: git svn init -s https://app.svn.beanstalk.com/repo Initialized empty Git repository in /path/to/repo/.git/ Authentication realm: ...
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 ...
3
votes
1answer
93 views

Does root not require a password to log in as a user?

Does root not require a password to log in as a user even though a password has been set for that user? When I am logged in as "root", su user logs me in as "user". There is no prompt for a password. ...
3
votes
2answers
137 views

SSH when to use public key and password?

I think I understand the difference between Public Key authentication and Password. But how do I decide which one to use and which one is most secure in what situation? Can anybody give me some real ...
3
votes
2answers
12k views

su - user doesn't work for users without a password

I've created a user on CentOS with useradd -M username. Now, I want to become that user just like su - username. It asks me for a password for that user but I didn't set a password for that user. As ...
3
votes
5answers
965 views

How to allow authentication with `sudo` using an alternate password?

I have been given a long password by my company for my Ubuntu system. This password is cumbersome to enter when authenticating with sudo repeatedly. Can I authenticate with sudo using a password ...
3
votes
3answers
223 views

Is there way to stop random software packages from remotely transferring your files?

I am running a bitcoin client on my archlinux computer. If somebody can get ahold of the wallet.dat file, located in the ~/.bitcoin/ directory they can steal my coins. I have minimal software ...
3
votes
2answers
600 views

How do you automatically elevate an automatic task to root privileges or is there an alternative approach?

I'm trying to write, in essence, an automatic deployment script for use by our development team and I know I can set up SSH to use keys so that I can automatically authenticate via key instead of ...
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 ...
3
votes
2answers
8k views

What is difference between pbrun and sudo command?

What is difference between pbrun and sudo command? I have seen people executing pbrun sudo su - what this means? I know su -, it will try to switch to root user. What speciality pbrun gives to sudo ...
3
votes
1answer
6k views

Can't login as root even after resetting the password

We're running a small Centos 5 server in a virtual machine for a class assignment. For reasons unknown, starting about a week ago a number of services started failing. When we tried to investigate we ...
3
votes
1answer
19k views

How to enable remote login?

Currently I can only login to my remote linux via the "ubuntu" user account, without a password (via SSH authentication). I have another user configured on the machine, and if I try to login with its ...
3
votes
2answers
107 views

Why user without any PASSWD entry in sudo config has to authenticate every time?

Consider this sudo config for two users: mary ALL = (ALL) NOPASSWD: /bin/ls, /bin/cat bob ALL = (ALL) PASSWD: /bin/sort Now, when user mary executes any command not in the list she has to ...
3
votes
1answer
3k views

mod_authnz_ldap bind as authenticating user instead of anonymously

I'm attempting to move as close to single credential as possible. We have a web application that has a fairly limited set of available authentication mechanisms but will (luckily) allow admins to tell ...
3
votes
2answers
1k views

Where does Samba 4 store user passwords?

Where does Samba 4 store user passwords? How can I import my password hashes from Samba 3 in Samba 4? I am using my own LDAP server with samba 3, and the password hash is stored within the ...
3
votes
1answer
82 views

Use ssh without trying ssh-keys

If I try to connect to a certain server with ssh example.com ssh aborts with Too many authentication failures because I have more than 5 ssh keys in my .ssh folder and it loops through all those ...
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: ...
3
votes
2answers
316 views

Why does my SD card need authentication to access?

I'm running Ubuntu 14.04 on a Toshiba Chromebook 2 via crouton. I recently reformatted a 256GB SD card that I keep in my chromebook at all times. My problem is that every time I try to access my SD ...
3
votes
1answer
2k views

How to set an expired authentication in Apache?

Using a simple virtual host, I've to set a timeout after X minutes (same of set an expired authentication) to force the user to re-insert its credentials. [...] <Directory /home/user1/> ...
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. ...
3
votes
1answer
556 views

Invoking PolicyKit/polkit via xinit/startx?

I recently upgraded a minimal installation of Ubuntu (with no full-fledged DE) from precise to saucy and since doing so I'm no longer able to mount removable drives as a normal user. I googled a bit ...
3
votes
3answers
8k views

CentOS use .pac file as proxy

I have to use a proxy with authentication to connect to the Internet. But I can't find any solution for this. I have modify my yum.conf, with a lot of possibilities: ...
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 ...
3
votes
1answer
5k views

Where to supply authentication details to the Network Proxy (Central Proxy) on Fedora?

My system is running Fedora 16 and I live in a campus where we use LAN to connect to the Internet. And for this, we use an http proxy with authentication (username & password). I tried putting the ...
3
votes
1answer
638 views

What's the best way to install a system-wide certificate from a website?

I want to use the Cisco Easy VPN to connect to the OpSource cloud machines. When I open the app, it directly shows a certificate error message, I suspect that the certificate is not trusted from their ...
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 ...
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 ...
3
votes
1answer
64 views

How to log messages from a pam module?

The problem I am trying to solve is that I want to know if a certain PAM config file is being used or not. The latest version of IBM MQ (V8) provides a PAM file /etc/pam.d/ibmmq. We're ...
3
votes
0answers
305 views

Wifi with WPA2-EAP MS-CHAPv2 authentication (username and password) during Debian installation

I am currently attempting to install Debian on my laptop computer. During the network configuration stage, I am prompted to "enter a passphrase for WPA/WPA2 PSK authentication". Unfortunately, I am on ...
3
votes
0answers
192 views

Why is my SSH authentication socket different from the man pages?

These two entries of man ssh-agent describe the SSH authentication socket: $TMPDIR/ssh-XXXXXXXXXX/agent.<ppid> UNIX-domain sockets used to contain the connection to the authentication ...
3
votes
0answers
2k views

Setup LDAP client on RHEL 6.5

I am preparing for RHCSA exams and trying to setup LDAP client on my RHEL 6.5 box I am connecting to the online testing LDAP server Here I don't understand the relationship among following 3 files, ...
3
votes
1answer
667 views

recover email from imap account using mailx

I am having problems fetching emails with mailx. My imap account uses ssl/tls connection with normal password authentication on port 993. I don't have any problems sending through smtp though. Here is ...
3
votes
0answers
808 views

Is there an alternative to OpenLDAP / Kerberos? [closed]

Are there ways to do centralized secure network-based authentication & authorization and user management that aren't OpenLDAP and Kerberos? Frankly, Kerberos is a nightmare to configure, leaving ...
3
votes
0answers
4k views

WBC_ERR_DOMAIN_NOT_FOUND only for a specific account

Platform: RHEL 5.10 Version: Samba 3.6.6-0.136 Only on a single VM, one of my co-workers is able to log into the VM using his AD credentials without issue, whereas my account appears to have trouble ...
3
votes
0answers
201 views

WGET - Authenticating root AND all children folders

Before I start the question off, I want to say that a similar question helped me get past the initial login. My issue is as stated below. There's a website that I'm trying to mirror. It is something ...
3
votes
1answer
464 views

Configure applications to ask for a user:pass behind a proxy

Here's the deal: I'm trying to set up a SQL server with Debian Linux, I managed to install Debian - but I can't get apt-get to work, since I'm behind a proxy. I already managed to setup Iceweasel to ...
2
votes
3answers
302 views

Can sudo replace su?

There is much duplication of functionality on Linux-based systems, for example these do the same thing: sudo --login --user <user> sudo su - <user> The sudo-only approach looks more ...
2
votes
2answers
2k views

How to get hashed password in /etc/shadow using getpwnam()?

Apparently there is a function (getpwnam) that given a username, will return the appropriate entry in /etc/passwd with the other details for that user (shell, uid, gid, etc.). However, I have no idea ...
2
votes
2answers
3k views

Why do my sshd logs show many tries on invalid ports?

My ssh daemon is setup to listen on port 2221. I have also disabled root login from ssh. I don't understand why in auth.log I see attempts to log on other ports (example with 4627 here). May 17 ...
2
votes
2answers
931 views

ssh login in Bash script

I've been working on a series of scripts to perform tasks on my remote server, but have gotten stuck at how to log in via ssh mid script, as I cannot enter the password automatically. Is there a way ...
2
votes
5answers
3k views

How to securely automate running commands as root with “sudo su -”?

hint (on client side, how to encrypt files/pwd's): # encrypt pwd with ssh key: openssl rsa -in ~/.ssh/id_rsa -outform pem > ~/.ssh/TEMP-id_rsa.pem 2>/dev/null openssl rsa -in ~/.ssh/id_rsa ...
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. ...
2
votes
1answer
570 views

basic explanation on NSS , LDAP and PAM

can anyone give me a basic explanation on what are NSS , LDAP and PAM and what they used for and what is their relationship/differences ?
2
votes
5answers
279 views

Simulate the remote host identification warning

I need to simulate the warning: @@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@ @ WARNING: REMOTE HOST IDENTIFICATION HAS CHANGED! @ @@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@ IT IS POSSIBLE THAT SOMEONE IS DOING ...
2
votes
2answers
128 views

Add a user wthout password but with SSH and public key

I want to add a user to Red Hat Linux that will not use a password for logging in, but instead use a public key for ssh. This would be on the command line.
2
votes
2answers
3k views

How to sign into an open Wireless Network?

I'm running Arch Linux on my netbook. My school have an open Access Point and we must sign into the network via a page which we are redirected to when we try to open whatever website if we are not ...
2
votes
1answer
242 views

SSH Authentication Mechanism

Doing a personal research project and I'm wondering: Why does SSH do its own mechanism negotiation rather than use SASL? At first I thought it might be to ensure confidentiality of the whole session, ...