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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0
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1answer
175 views

Password length and complexity

I am using CentOS and I want to set the minimum password length, minimum password expiry , maximum password expiry and password complexity in my system. I have looked over some tutorials to change ...
1
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1answer
33 views

Replacing graphical sudo prompts with sudo command

I'm trying to replace gksudo, pkexec and its ilk with sudo. However, I'm told that using sudo <graphical_program> is a bad idea. Would the following work as a decent replacement? sudo -H <...
1
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0answers
288 views

Fedora 20. Authentication requires a different password from su

In Fedora 20 (using Mate desktop) I have tried to change the default keyboard layout from US English to UK English, but am asked for "Authentication". The password I have for su is not accepted, and I ...
2
votes
2answers
200 views

Making su ask for password multiple times

Is there some way to make su ask for the password again in case of a wrong password (just as sudo does)? Initially I thought of this: while ! su -c foo; do read -n 1 -p "Retry(y/n)?" ch if [[ "$...
1
vote
1answer
235 views

Dynamic password authentication

I would like to know how can I (and if it's possible) create a dynamic authentication for a user in linux. The server would change the user password periodically and the user would use a program (...
5
votes
1answer
4k views

PPTP VPN error: LCP terminated by peer

I cannot connect to my PPTP VPN server, even though the CHAP authentication succeeds. This is from /var/log/syslog: Jun 11 07:27:22 aspire pppd[32221]: CHAP authentication succeeded Jun 11 07:27:22 ...
2
votes
3answers
322 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 ...
3
votes
1answer
4k views

A messagebox keeping popping up in my centos VNC server asking to change proxy settings?

I have included a screenshot of what it looks like. It keeps appearing and in the morning you to close it 50 times. Could you please help me identify where the problem lies? NOTE: It's CentOs 6 ...
3
votes
1answer
692 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 ...
-1
votes
1answer
353 views

How do i deal with HP Device Manager requiring authentication to remove print jobs?

I have Fedora 20, with Gnome 3 Classic, and have installed Okular to read and, especially, print pages from, .pdf files. I want to print only a few pages, but in my frustrated attempts to set this up ...
3
votes
2answers
4k 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 15:...
0
votes
1answer
575 views

Creating MySQL database and user without password

I am building a set of bash scripts which basically prepare apache virtual hosts, git repositories and other stuff on a cloud server. So far so good, everything is working, but a big problem occurred: ...
0
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2answers
680 views

“NOT AUTHENTICATED” warning trying to install rdesktop on almost-fresh Mint 16 install

Linux Mint 16 (Ubuntu-based) 32-bit running on a netbook. Installed Wine and Skype, and all updates. Went to install rdesktop (typed rdesktop in the gnome menu search, chose 'install rdesktop'), and I ...
1
vote
1answer
94 views

How does the authentication process with the salted hash in shadow work

Does the supplied password during login get converted to a salted hash and then compared to the one in /etc/shadow? /what if the user is in LDAP but not in the shadow file? Would it use kerberos?
1
vote
2answers
655 views

Reset password for regular user who is locked out

I'm a complete noob in Linux and I'm stuck in a situation where I'm logged in an Linux box from putty but on of my colleague, who was trying to login on same machine from his machine blocked my user ...
1
vote
1answer
311 views

Connecting to Github from server

I am trying to connect to Github from a server running Jenkins. To do this, I'm copying my public key from another server, into the authorized_keys on the new server. All I'm getting is the ...
2
votes
1answer
655 views

login 'authentication failure' by non-root user, can login only by root [closed]

In my CentOS 6.0 system, working since months, suddenly stop authenticating non-root users, in graphical mode. I have checked necessary /etc/pam.d/* files, but those are unchanged. SELinux is ...
1
vote
1answer
161 views

How to get the authentication status from the last PAM module run

If I have the following PAM stack: auth required default_pam.so auth requisite my_custom_pam.so .... How do you obtain the authentication status from the last/previous PAM module run for use in ...
0
votes
0answers
294 views

Get user login name and address on bad login attempt [Dovecot]

Background I am trying to develop a method to ban users who exhibit strange behavior when logging into Dovecot by obtaining their POP-ID/login name and IP address. I want to send that information to a ...
2
votes
1answer
184 views

Obtain pop-id or IP address when client logs into Dovecot server

Background I have been doing some research on the Dovecot mail server documentation on ways to get client information when a client connects to the server. I am interested in using these to program an ...
0
votes
1answer
610 views

Authentication failure for FTP server [duplicate]

I followed this link to install ftp server. And also added ftp user(ftpuser) and also added ftp password(1234567). But when I am using this password in any wordpress site or any ftp software such as ...
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 ...
1
vote
1answer
2k 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 ...
5
votes
1answer
4k views

Command line printing with a Samba printer requiring authentication

Is there a way to print to a Samba printer requiring authentication by providing the credentials on the command line (e.g., with lpr)? I managed to store the credentials in GNOME Keyring and when I ...
0
votes
2answers
101 views

How to set Linux to ask for authentication when running potentially dangerous commands?

I've faced times when I accidentally ran dangerous commands and lost all my data. How do I set Linux to ask for current user password or root user password when running potentially dangerous commands ...
4
votes
2answers
34k views

Using curl to access basic auth protected website via proxy (polipo)

I am trying to download a file protected via basic auth: curl "http://User:Pass@example.com/blub/bla.bin" This is working fine. As soon as I tell curl to use my locally installed polipo it fails: ...
2
votes
1answer
831 views

Gnome-shell authentication dialogue fails, how to debug which app is using it?

I am using ubuntu 13.10 with gnome shell 3.8.4. I used to use gnome online accounts for empathy and other things, but then I stopped using them. And then gnome shell started to show authentication ...
0
votes
2answers
135 views

In Fedora 17 kde I don't know user or password to authenticate printer installation

I am trying to set up a new computer with Fedora 17 and KDE both working ok. I have plugged in an HP laser USB printer, and am trying to set it up. I enter "system settings -> printers" from the KDE ...
8
votes
2answers
8k views

Lenovo T440s Fingerprint reader in Fedora 20

I just got my new Lenovo T440s and installed Fedora 20 with Gnome 3 on it. Everything runs smoothly, except for the fingerprint reader. Its got a Validity VFS5011 (138a:0017) device which is not yet ...
8
votes
3answers
441 views

Trap: can't su as root, can't change group to wheel, ssh as root prohibited

Is this a trap? I made these steps in FreeBSD 10: 1) ssh as root prohibited 2) logged as user 3) su as root 4) as root chsh changed name of user "user" to "luser" 5) exit from ...
13
votes
3answers
39k 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 ...
1
vote
2answers
12k 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. ...
2
votes
0answers
1k views

Enter user authentication details for a printer?

I have a printer which is configured using the correct drivers. However, the printer requires user authentication (i.e. a username and password) to print. Where are authentication details usually ...
3
votes
0answers
847 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 ...
1
vote
1answer
6k views

How to configure Samba to use Windows's login ID?

I'm trying to access the Linux share folder from Windows using Windows's domain authentication. I come across the integration of Windows Active Directory into Samba on a Linux box, thus I have this ...
1
vote
2answers
547 views

Is there any shared filesystem based on public key authentication?

I normally use NFS, however I am not so comfortable with the security as basically a root user can just change his UID to an arbitrarily one in order to obtain access to a shared folder. Moreover, ...
14
votes
3answers
20k 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
1answer
880 views

How do I reset RHEL6 to autocreate home directory upon login?

I am using a RHEL6 host that is set up using LDAP for authenication. Upon first login it is supposed to create the home directory for the user (e.g. /home/gisle where gisle is my login username). I ...
1
vote
3answers
2k views

SSH public key authentication works on LAN and not from WAN

I've setup my SSH server to use public key authentication. When I connect to my server on local network, it authenticates. But it doesn't when I connect over the internet. I don't think the problem ...
0
votes
2answers
2k views

Ssh 'access denied' from one host but not the other

Consider the following scenario: I have a Debian-ssh-server setup and exposed it to the internet for some time for testing. Also I have an account which is basically configured as root in the sudoers ...
2
votes
0answers
323 views

SSH login from external authentication

Here is what I try to accomplish: I have a server with a git repository. I use ISPConfig as control panel for our websites and I want to integrate the ISPConfig API for email authentication as second ...
1
vote
1answer
508 views

How do I impersonate a windows domain account user from a linux process?

I'm running a process on a Unix box (I think it's a recent version of Red Hat, I can check for more detailed info if relevant), under a local user. I would like to access some network resources, via ...
2
votes
1answer
3k views

tinyproxy with user authentification

Does anybody have a solution that'll make tinyproxy work with user authentification like pam_auth at the squid proxy? I don't want to create a SSH-Tunnel and allow only localhost.
1
vote
1answer
431 views

Mount home partition on user login

I got a VPS with a user dedicated to store my files. As i am aware of the current situation with the NSA and many other governments, and my VPS is hosted on a doubtful country i would like to ensure ...
0
votes
1answer
3k views

Setting up the superuser password for the first time

How can I set up the super user password for the first time in Zorin OS, since the installer didn't ask me to provide one. I have experience with Fedora and openSUSE, but they asked me for the ...
7
votes
2answers
957 views

PAM - required and sufficient control flag

I'm studying PAM, and I'm a bit clueless about the meaning of some combination of control flags. From the Red Hat documentation we have: *required failure of such a PAM will ultimately lead to the ...
2
votes
3answers
2k views

How to do svn update without password on crontab [closed]

I'm new to svn and ssh. I'm trying to do svn update of 5 repositories in my local system every 3 hours on crontab. So, to achieve this I have setup ssh passwordless login using the below steps: ...
3
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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
1answer
585 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
2answers
138 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 ...