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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3
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0answers
1k 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, ...
4
votes
1answer
65 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 ...
2
votes
1answer
248 views

public key authentication without authorized_keys file

I have a lot of ssh public key logins on a Linux server, e.g.: Jul 25 11:41:01 host sshd[24594]: Accepted publickey for root from xxx.xxx.xx.xx port 33374 ssh2 This is strange for me since there's ...
3
votes
1answer
319 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/> ...
5
votes
1answer
796 views

2 Factor Authentication in SSH using public key and PAM

I'm trying to setup 2 Factor Authentication. I want the user to login successfully if: The public private/public key matches (authentication method: publickey) or the password is correct My pam ...
6
votes
1answer
358 views

Apache Authorization for the Allowed Users?

I have read the answer to this question: http://stackoverflow.com/questions/4102763/apache-basic-authentication-except-for-those-allowed It helped me understand how to not authenticate some users ...
2
votes
1answer
63 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. ...
1
vote
1answer
88 views

Apache authentication mutiple domain but same subdirectory

I've got several sites: example.com, example1.com, and example2.com in my wordpress. All of them point to my server's /public_html folder, which is my Apache root folder. What do I need to add to my ...
-1
votes
1answer
71 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
vote
1answer
29 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
vote
0answers
232 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
97 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
83 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 ...
2
votes
1answer
1k 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
181 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
1answer
663 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
343 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
142 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 ...
1
vote
2answers
2k views

Why do my sshd logs show many trys 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 have attempts to log on other ports (example with 4627 here). May 17 ...
0
votes
1answer
382 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
votes
1answer
154 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
62 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
219 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
179 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
250 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 ...
0
votes
0answers
56 views

Hit “sasl_decode error=-1” while sending mail via sendmail server on RHEL

Having installed sendmail and openwebmail on RHEL workstation 6.3, I can send email through webmail(cgi-bin/openwebmail/openwebmail.pl), but failed to interact with sendmail server in Perl script as ...
1
vote
0answers
53 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
23 views

KRB5 auth with samba

I'm attempting to setup a samba share on RHEL6 for a group of users. There are quite a few of them with very little technical experience so having them SSH in to reset smbpasswd is asking a lot. We ...
0
votes
0answers
131 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
94 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
265 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
1k 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 ...
0
votes
1answer
533 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
951 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
76 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 ...
3
votes
2answers
11k 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
519 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
104 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 ...
5
votes
2answers
5k 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
286 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 ...
12
votes
2answers
17k 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 ...
0
votes
2answers
4k 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
858 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 ...
2
votes
0answers
424 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
3k 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
244 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, ...
6
votes
2answers
4k 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
569 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 ...
0
votes
3answers
1k 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
356 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 ...