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31
votes
2answers
10k views

Why is there a big delay after entering a wrong password?

I notice a weird (well, according to me) thing about passwords. For example, if I type an incorrect password during login, there will be a few seconds' delay before the system tells me so. When I try ...
16
votes
4answers
3k views

Can I find out which ssh key was used to access an account?

Is it possible to find out which ssh key was used to access an account? I have an account on a server that I let several (trusted!) people have access to via ssh. I'd find it useful to be able to ...
13
votes
2answers
710 views

SSH ignores characters after correct password string?

Remote machine 10.10.10.1 has password "asdFGH12" for user named "user". I'm able to log in even if I type in password "asdFGH12dasdkjlkjasdus" or any other characters after the "asdFGH12" string. $ ...
11
votes
3answers
293 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 ...
10
votes
3answers
839 views

How can I lock my own account from remote ssh login with password?

I don't want to disable remote login with password altogether, but I want to make it so that my account is only accessible with key pair authentication (there are other users who wants to use ...
7
votes
3answers
1k views

Why does my sudo ask for password only once but evaluate thrice?

$ sudo some_command Password: Sorry, try again. Sorry, try again. Sorry, try again. sudo: 3 incorrect password attempts $ This is what my shell prints when I enter a wrong password to a sudoed ...
7
votes
2answers
388 views

iPhone type login screen?

The person that introduced me to Fedora had somehow made his login screen so that instead of typing in a password he used the "connect the dots" password that's popular on phones. Eg On my ...
6
votes
4answers
736 views

Is it possible to change password database file(/etc/passwd) in linux?

Is it possible to change password database file(/etc/passwd) to some other file. How does this authentication mechanism work internally ? Does it depend on pam ?
5
votes
3answers
1k views

How can I make a user able to log in with ssh keys but not with a password?

I would like to create a user and have no password. As in you cant log in with a password. I want to add keys to its authorized_keys by using root. This is for my automated backup system.
5
votes
2answers
474 views

How to check for empty passwords?

Looking at all the ssh-login attempts by script-kiddies I assume that there are messed up systems connected to the internet that have password-less accounts set up. But how to check a Linux/Unix ...
5
votes
2answers
3k views

Not able to ssh in to remote machine using shell script in Crontab

Below is the script which i am trying to run, which runs without any issue for i in `seq 200 2100` do usr=(`ssh -t -t -o ConnectTimeout=60 machine$1 finger | tail -1 | awk '{print$1}'`) echo ...
5
votes
2answers
6k views

How to telnet via proxy authentication?

I am behind a proxy server in my college. It uses a simple username and password authentication. And i connect to the proxy server to port 3128. now i want to telnet simply to say any website on the ...
4
votes
3answers
4k 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 ...
4
votes
3answers
216 views

login and su internals

I am trying to understand how user permissions work in Linux. The kernel boots and starts init as root, right? Init then runs startup scripts and runs getty (agetty), again as root. Agetty just reads ...
4
votes
2answers
466 views

How to disable “Shake password dialog when authentication fails” of Gnome Screensaver?

Is there any way to disable the animation which occurs when attempting to unlock gnome Screensaver and failing? Currently the password dialog shakes back and forth and for some reason on some laptops, ...
4
votes
6answers
807 views

Identity Management with ActiveDirectory

What is the best, or most reliable, way to manage my Unix/Linux user accounts with ActiveDirectory? Or, is this even feasible?
4
votes
3answers
1k views

SSH authentication: either SSH keys or one time password

I have an Ubuntu 10.04 Linux server that I normally ssh into (from my home machine) using ssh key authentication. However, sometimes I need to ssh remotely from potentially insecure machines (like ...
4
votes
1answer
381 views

Custom PAM modules and security considerations

I am writing my own PAM module that will be part of an application that I am developing, but I'm not sure exactly where to put it. My module basically does network-level authentication (with other ...
4
votes
1answer
111 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
607 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
2k views

Preventing `passwd` for asking for the local password

I have setup the sever to only use LDAP for authentication by using authconfig-tui. Everything works well but, when I run passwd, I get two prompts for a password: [beamin@rhel6-test-server1 ~]$ ...
3
votes
2answers
155 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
1answer
295 views

Does the SFTP server accept passwords at all?

I'm trying to connect to a sftp server via sftp USERNAME@SERVERNAME. Whatever I do, I get "Permission denied (publickey)." Googling doesn't help as everybody recommends switching to key-based ...
3
votes
1answer
2k 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
151 views

How are loaded SSH keys referenced by name?

I'm using chef's knife ec2 tool which requires the name of a loaded SSH key (that was created in the Amazon EC2 control panel) It seems strange to me that it uses a name to reference the keypair - ...
3
votes
1answer
115 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
2k views

Suddenly, I Can't login with correct password (greeter & tty)

This might be a duplicate of other password related questions but it's somehow eccentric. I have 3 accounts in my Ubuntu 12.10 system (one standard and two administrators). One of the administrator ...
3
votes
1answer
259 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
219 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
1answer
71 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
142 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
2answers
1k 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
3answers
312 views

rsync server/daemon security

I have a NAS (Netgear Readynas NV+) at home and a linux (Arch) box at work that is always on. The linux box is already running an ssh server/daemon and the NAS is already running an rsync ...
2
votes
1answer
1k views

Authenticating with x11vnc: what's the difference between -auth and -rfbauth?

I'm on xubuntu 11.10 trying to setup x11vnc server. I followed instructions here and I can connect to VNC server - but it never asks me for password! Is there a difference between these 2 options: ...
2
votes
1answer
128 views

Restrict two way SSH and Apache authentication to non-local networks

I am using Google's open-source PAM module for two-way authentication for SSH logins and certain Apache directives. It works great, however I would like to use this only when trying to log in from an ...
2
votes
0answers
47 views

SSL Configurations for Intermediate certificate

I had implement a mutual certificate authentication and it worked successfully for following steps : create root ca (self-signed) create server certificate and sign it with ca private key create ...
2
votes
1answer
933 views

How to configure for an Authenticating Proxy Server

My work proxy server requires authentication with the Microsoft AD domain user credentials. Everybody knows how it works: If you log in on a Windows workstation, your "Internet Explorer" browser based ...
2
votes
1answer
2k 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 ...
2
votes
0answers
514 views

nsswitch cache and nscd

I have an LDAP directory server installed that stores all the user data in one server and I have an ongoing authentication mechanism using pam to request user information from it. This works very ...
1
vote
5answers
305 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 ...
1
vote
1answer
4k views

Execute a script automatically through pbrun?

There is a Unix environment named sftwrk01, uatwrk01, intwrk01 and some more I need to check the logs in each environment everyday by login in as below (through pbsu which is a wrapper for pbrun): ...
1
vote
1answer
26 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, ...
1
vote
1answer
523 views

Script to get file from SFTP and run it

We have 5 servers running our code: A, B , C, D and E. From a local machine, we sftp the file to A. Then ssh id@A su - applicationname sftp id@A get <file> bye tar -xzf <file> logout ...
1
vote
2answers
170 views

Command-line web browser with Kerberos authentication?

QUESTION: Is there a Kerberos-friendly web browser usable via an SSH console? I have tried links but it does not seem to work with Kerberos (the webapp asks me for login/password even though I have a ...
1
vote
1answer
151 views

Setting up Samba to use AD server for authentication?

I am looking for howtos or instructions on setting up Samba to use an AD server for authentication instead of using a Samba password file. Pointers to documentation helpful, especially the right ...
1
vote
1answer
7k 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 ...
1
vote
3answers
5k views

vsftpd fails pam authentication

Moving a tried-and-true vsftpd configuration onto a new server with Fedora 16, I ran into a problem. All seems to go as it should, but user authentication fails. I cannot find any entry in any log ...
1
vote
1answer
253 views

Can't su root after editing PAM confiugration on Rackspace Linux box

I've just hosed a system. Working on pam-ldap on an Ubuntu box, I've run pam-auth-update and told it to override local modifications (which had previously allowed for sudo su, but I was having issues ...
1
vote
2answers
554 views

SSH on my local network - problem with login

I'm having problem with logging into my local-network-linux (server) ssh with Putty (and with Linux terminal, too) When my server shows me request to insert username, I insert "root" and I do press ...
1
vote
2answers
710 views

setting up ssh public key

Okay, so I'm trying to setup a login for logging in with ssh, using a public key. First, I am using puttygen to generate a rsa-ssh2 public key using a passphrase. I followed the directions and ...

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