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
26 views

Ubuntu remote desktop user using a key-based login

I have an Ubuntu 14.04 LTS set up and I have a which authenticates using a private key to connect via PuTTY. Is it possible to use remote desktop from windows 7 (xrdp) with key-based login?
2
votes
2answers
23 views

temporarily disable login using one specific ssh key

On my server, I have several public SSH keys in ~/.ssh/authorized_keys. I would like to temporarily block/disallow/deactivate one key. I want to prevent the user to log in using this key now. but I ...
2
votes
1answer
33 views

What's the correct way to authenticate a user without PAM?

as my related question doesn't seem to get much love, here another one: What's the proper way to authenticate a user via username/password prompt in Linux nowadays? In principle, I suppose I would ...
2
votes
0answers
24 views

Login to Linux using a trusted Active Directory

I'm having trouble to log in to Linux using a trusted Active Directory. The machine is connected to an Active Directory that we are responsible for in the project, but most of the users who will use ...
0
votes
1answer
20 views

Authconfig doesn't find all ldap groups

My (soon to be) admin account is in two groups: # ldapsearch \ > -v \ > -H ldaps://localhost:636 \ > -D "${l_dirmgr}" \ > -w $(cat ${f_dirmgr_passphrase}) \ > -b ...
2
votes
1answer
48 views

iptables, what is truly open?

We have an RSA appliance, I've reviewed the firewall rules on this appliance to determine what ports are enabled. To me, it looks like its wide open; but the vendor states that I am wrong about this, ...
0
votes
1answer
15 views

Smart Card local authentication

Is it possible to use smartCard for local authentication ? So that, rather userID/password combination, an user can authenticate himself by inserting card and by providing it's PIN number. RDesktop, ...
1
vote
1answer
37 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
69 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 ...
1
vote
1answer
28 views

Allow a python application to run if the user's password is wrong

Is it possible to let a python program execute only if a wrong password is given at the login screen of my raspberry pi?
0
votes
0answers
37 views

While trying to ssh, pam_ldap always sends the password “INCORRECT” causing bind to fail

I installed ldap-auth-client nscd ldap-utils on lubuntu 14.04 running on a banana pi. I can successfully bind as the user using ldapwhoami, but I cannot log in via ssh: Auth.log: Oct 21 02:12:05 ...
0
votes
1answer
27 views

xscreensaver sometimes unlocks locked screen automatically, after returning from monitor standby mode

I am using xscreensaver to lock my screen. Additionally to that, my monitor goes to "standby" , i.e turn display off, after 30 minutes of inactivity. It has happened to me twice now, that I have ...
0
votes
0answers
35 views

Why on my Linux PPPoE connection displays sometimes authentication failure?

Here is my log: Oct 18 09:51:52 -desktop pppd[2764]: Plugin rp-pppoe.so loaded. Oct 18 09:51:52 -desktop pppd[2766]: pppd 2.4.5 started by root, uid 0 Oct 18 09:51:52 -desktop pppd[2766]: PPP session ...
2
votes
0answers
14 views

Externally authenticate user within PAM session/PAM session within PAM session

Is there a way of properly authenticating a user from within a custom PAM session? I am currently writing my own PAM authentication module which allows the user to login via an external token. This ...
1
vote
1answer
33 views

How to disallow usage of an LDAP root account

I am responsible for a couple of servers at my university. All of these machines are configured to talk to the LDAP server of my departement to allow centralised user logins. On this LDAP server there ...
2
votes
1answer
88 views

DSA/RSA keys work with Linux but not HP-UX

I have an NFS mount that I use to log into many Linux/Unix servers. I created a passphraseless RSA and DSA key from with I copied the id_rsa.pub and id_dsa.pub files over to authorized_keys. total 9 ...
3
votes
5answers
164 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 ...
1
vote
1answer
48 views

What prevents RHEL7 default PAM config's “nullok” option from allowing empty passwords?

The config /etc/pam.d/password-auth is included by several PAM services including sshd. This is its auth stanza: auth required pam_env.so auth sufficient pam_unix.so nullok ...
1
vote
0answers
31 views

Cannot login to svn server

I have a SVN server on my Raspberry Pi (Raspbian). It has a project under the directory /welcome, I want to add users to it. My users would be admin with password admin and user2 with password ...
1
vote
1answer
116 views

Cannot login for one user, changing password have no effect

I have change the user's (user1) password using root passwd user1 but when i tried to ssh user@localhost or through gdm or tty it always failed the journalctl log shows Failed password for user1 ...
0
votes
0answers
45 views

pam.d password hardening: nullok

In most all pam.d documentation or linux distributions that I saw, the recommend "secure" configuration for password is the following: password required pam_unix.so sha512 shadow nullok ...
0
votes
0answers
45 views

log freeradius ip address with username

i configured a mikrotik with linux(freeradius+rsyslog+mysql) to authenticate and log users activity. now i want to log users visited urls, but only ip addresses of users and visited urls are logged. ...
0
votes
0answers
62 views

Authenticating To Multiple LDAP Servers

Owing to a corporate strategy I am moving human user authentication from an implementation of LDAP locally to a centralized Active Directory domain. The problem is that we have a tightly constrained ...
1
vote
0answers
414 views

Samba prompts for a password twice

I have a relatively new samba install configured to give Windows users access to some log files on a syslog server ("littleEngineer"). However it's prompting for a password to just get a share listing ...
3
votes
1answer
66 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 ...
0
votes
2answers
465 views

Authentication very slow (both with ssh and su)

I'm having a problem on one of our production servers where the login attempts become progressively slower as time passes. After roughly 5 days it becomes so slow that some critical processes/cron ...
0
votes
0answers
43 views

authenticate url with asked credentials

there is a URL http://server, when I open this url it ask for username and password (.htaccess authentication), this URL works fine in browser. This is the webpage not the browser which ask ...
0
votes
1answer
36 views

Howto Tell if a System authenticate with password only or through PAM

If my computer has the pam package installed and has the directory /etc/pam.d/sshd, does it mean for sure when I ssh to my computer, I am authenticated through pam modules? The /etc/pam.d/sshd looks ...
0
votes
0answers
48 views

Samba 3 file sharing access permission problem onWindows

I'm trying to set permissions on a server RHEL v5 whith Samba v3. The configuration of /etc/samba/smb.conf is [project] valid users = proyecto, admin writeable = yes ...
2
votes
0answers
640 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
59 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
232 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
76 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
336 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
247 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
57 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
42 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
49 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
26 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
167 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
81 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
47 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 ...
1
vote
1answer
564 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
162 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 ...
1
vote
1answer
268 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 ...
2
votes
0answers
239 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
113 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
807 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
357 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
113 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 ...