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
636 views

Certificate extensions in generating and signing certificartes using openssl

References: SSL Configurations for Intermediate certificate How to add my own created certificate authority to system trusted repositories Why I can't find a page which tell me what's the kind of ...
0
votes
1answer
2k 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 ...
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 ?
0
votes
2answers
2k 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
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 ...
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: ...
8
votes
3answers
236 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 ...
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 ...
1
vote
1answer
842 views

SSL handshake failure with Shibboleth [closed]

I am using Shibboleth for single user authentication and it needs a ssl configuration which facilitates the user authentication process. Before it was working fine but now I am facing a SSL handshake ...
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?
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 ...
11
votes
2answers
10k 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
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 ...
17
votes
4answers
1k views

How do I tell what program is asking for a password?

I'm getting an occasional "Authentication request" dialog from Gnome, and I don't know what program is asking or even which account it's talking about. [email redacted] is an email address of mine, ...
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 ...
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 ...
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 ...
4
votes
2answers
1k 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: ...
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 ...
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 ...
7
votes
3answers
11k views

ssh remote server on some port other than 22 without password

I am usually connecting to the remote server with ssh user@server.com -p 11000 and then giving the password each time for user. How should I avoid entering the password each time I connect ...
1
vote
1answer
122 views

How to recover from this NIS & NFS client error?

I have a centralized NIS and NFS server on my server. I use this server to control 100 Linux clients, /$home/ directory and authentication are served by the centralized server. The other day in one of ...
5
votes
2answers
3k 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 ...
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 ...
11
votes
4answers
658 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
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
115 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

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
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
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 ...
3
votes
1answer
282 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 ...
1
vote
0answers
412 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 ...
0
votes
0answers
104 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
79 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 ...
3
votes
1answer
7k 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 ...
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
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 ...
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 ...
7
votes
2answers
4k views

How can I set up SSH on Linux to log in password-less?

My Raspberry Pi is running the default Debian image and has SSH enabled. I log into my Pi as follows: ssh pi@<IP-address-of-my-Pi> I have to enter my password every time. Can I somehow make ...
0
votes
2answers
170 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 ...