Secure Shell (SSH) is a protocol primarily for encrypted shell connections. This tag is also used for questions about sshd and openssh, the two standard applications for using SSH.

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Limiting Failed SSH Logins

I would like to limit failure retries on my Fedora machine to 5. I think I can accomplish it with PAM. But was unable to to do this. I have referred to this article to do this ...
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3answers
2k views

Why is SSHD hanging at “Server accepts key”

I've been ssh'ing to this box without problem for a year using public-key authentication. No changes have been made to the client or server's ssh config. Now, ssh connections never complete or fail, ...
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2answers
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SSH configuration, publickeys, Permission denied (publickey,password). error

My task: login from Mac OS Snow Leopard client to Ubuntu 10.10 server without password. Commands: client$ mkdir ~/.ssh client$ chmod 700 ~/.ssh client$ ssh-keygen -q -f ~/.ssh/id_rsa -t rsa Enter ...
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3answers
3k views

How to fix “Could not open a connection to your authentication agent.” error when trying to add ssh-key?

I'm using Ubuntu server 10.04. ssh-add /foo/cert.pem gave the following output: Could not open a connection to your authentication agent. These are my running processes: ps -aux | grep ssh ...
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1answer
1k views

SSH invalid open call: O_CREAT without mode

I'm having troubles to connect to my server via SSH. It runs Ubuntu 12.10. I can access the server using a normal user, but I can't access it using root. It seems ssh authenticates well, but the ...
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4answers
280 views

Reimport ssh certificate after every reboot for GIT PUSH over ssh to work

I am using OSX 10.8 on my macbook air, i have git configured to push my repository to an EC2 instance via ssh. Everything works fine with that. The only issue is that after every reboot, I have to ...
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2answers
168 views

How to create a new user and exempt the user of key authentication?

1 I have configured Ubuntu server with Key authentication & it is working fine. I have disabled password authentication for key authentication to work. Server is always accessed via remote ...
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2answers
3k views

SSH connection problem - allowed from LAN but not WAN

I tried to setup my Arch Linux installation to be an SSH host, but here is the thing: I can ssh localhost, it fails to login via public key and asks for username and password, but still able to ...
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5answers
4k views

Can't login using ssh as root

I am trying to virtualize an old linux server, and the PtoV software requires a password login as root via ssh. However, the root login is being prevented with a "Permission Denied" error on the ...
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4answers
493 views

What's the benefit of using asymmetric keys over passwords?

Is there a benefit to using keys over regular passwords when it comes to logging into a remote server over SSH? (Besides not having to remember/input that password)
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2answers
182 views

Adding new users

I have an FTP server that is running Fedora Core release 6 (Zod) the problem is I need to create new users and I have root access saved in WinSCP, so I can run useradd or adduser via the fake ...
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1answer
2k views

SSH access from outside to a pc inside network

I have a static IP and ADSL router linked to a linksys wireless router to which all my machines are connected. I would want to setup SVN on one of machines and provide SSH access which should be ...
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2answers
834 views

SSH Public Key Authentication only works if active session exists before

I have a rather strange problem with my SSH configuration. I set up my server with the help of a Remote Access Card and configured everything with a KVM viewer. So while being logged into the server ...
0
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2answers
777 views

SSHD real-ip behind haproxy

I'm trying to setup an ssh over https connection using haproxy. I'm currently looking for a way for SSHD to get the source ip from haproxy, similar to reading X-Forwarded-For or X-Real-IP headers. ...
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0answers
422 views

ssh reverse tunnel port forwarding connection fails

Updated: diagram http://s22.postimg.org/b2jfgawup/diagram_ssh_tunnel_a1.png I am able to do a reverse port forwarding through the PUTTY GUI with settings similar to below. once I apply this setting, ...
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2answers
864 views

Forward SSH request to an External Server to an Internal Server [duplicate]

I have a VM config currently where I have 1 external IP pointing to a VM with an Nginx HTTP Reverse proxy serving HTTP Web Pages from several internal VMs without external IPs. I need a similar setup ...
0
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2answers
4k views

How can i forward the http and ssh port to my internal server using iptables

I do not have the router so i make the Linux system into router having centos 6.4 for forwarding the Public network traffic to my local LAN.It has the two NIC card. one for public ip (eth1) and ...
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1answer
10k views

“Protocol mismatch” when trying to access tunneled HTTP port

I'm using Mac 10.7.4 and I have an HTTP service running on port 8082 of a remote server, which I can only access through an intermediate server. So I execute these tunnel commands ssh -L ...
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4answers
5k views

Monitor file copies with SCP done via SSH

Is there a way to keep a log of the files copied using SCP? I am administering a server which contains some files that should be monitored (in a specific folder and its subfolders), so when someone ...
0
votes
3answers
917 views

How do I block an email sender using SSH

Having a bit of a nightmare with our Linux server. Somehack is using our server for spaming. I sanitaized all inputs, have captcha image, change passwords, etc. but still. Somehow they keep on doing ...
0
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1answer
392 views

EC2 Instance Store to EBS Can't connect to SSH

I followed every line on this tutorial: http://webkist.wordpress.com/2010/03/16/creating-an-amazon-ec2-ebs-ami-from-a-running-instance/ to create a EBS instance using a AMI based on a Instance Store ...
0
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0answers
678 views

changing ssh port. Useful?

i will buy a dedicated server soon. I would like to know if changing the default port of ssh may be useful for security or it's completly useless. And if it's useful which ports range should I change ...
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2answers
1k views

SSH and port forward socks proxy

I would like to setup an ssh tunnel that includes 3 machines. One machine I want to make http requests from but can only connect to a central server and outbound port 80 requests. The server is a ...
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2answers
290 views

how to ssh to the machine behind the firewall? [duplicate]

Possible Duplicate: SSH to a computer that will then SSH to another computer I have 3 Linux machines A, B and C. I can ssh from A to B; B to C but not from A to C directly because C is ...
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4answers
49k views

How to change sshd port on Mac OS X?

I want to change which port sshd uses on a Mac server. For example, let's say from port 22 to port 32. Editing /etc/sshd_config does not seem to work. Does anyone know how to change it? I'd prefer ...
108
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1answer
32k views

Create a public SSH key from the private key?

Let's suppose I have a SSH key, but I've deleted the public key part. I have the private key part. Is there some way I can regenerate the public key part?
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10answers
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How can I run arbitrarily complex command using sudo over ssh?

I have a system that I can only log in to under my username (myuser), but I need to run commands as other user (scriptuser). So far, I have come up with the following to run the commands I need: ssh ...
41
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10answers
11k views

Why is SSH password authentication a security risk?

Most guides for OpenSSH configuration advise to disable password authentication in favor of key-based authentication. But in my opinion password authentication has a significant advantage: an ability ...
30
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8answers
20k views

Allow SCP but not actual login using SSH

Is there any way to configure a user on a Linux box (Centos 5.2 in this case) so that they can use scp to retrieve files, but can't actually login to the server using SSH?
37
votes
4answers
28k views

How can I launch a screen session with a command over ssh on a remote server from my desktop?

I want to be able to launch screen sessions on remote servers from a single ssh command on my desktop. However, screen seems to need a terminal, which is not available when running a command through ...
18
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6answers
64k views

How can I edit the welcome message when ssh start?

I have a vps for my website hosting. It is running a ubuntu server. Every time I logged in my server by ssh, it displays a lengthy welcome message in my terminal. Linux node61.buyvm.net ...
58
votes
2answers
27k views

ssh hostname returns “Bad owner or permissions on ~/.ssh/config”

When I try to ssh to another box, I get this strange error $ ssh hostname Bad owner or permissions on ~/.ssh/config But I made sure that I own and have rw permissions on the file: ls -la ~/.ssh/ ...
37
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4answers
13k views

How do I make ssh fail rather than prompt for a password if the public-key authentication fails?

I've got a script that ssh'es several servers using public key authentication. One of the servers has stopped letting the script log in due to a configuration issue, which means that the script gets ...
23
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2answers
25k views

public key authentication fails ONLY when sshd is daemon

I have no clue on how this happens. The distro is Scientific Linux 6.1 and everything is set up to perform authentication via public key. Yet, when sshd is running as a daemon (service sshd start), it ...
48
votes
1answer
32k views

SSH use only my password, Ignore my ssh key, don't prompt me for a passphrase

This is a question regarding the OpenSSH client on Linux, MacOSX and FreeBSD. Normally, I log into systems using my SSH key. Occasionally, I want my SSH client to ignore my SSH key and use a ...
27
votes
8answers
27k views

change directory automatically on ssh login

I'm trying to get ssh to automatically change to a particular directory when I log in. I tried to get that behaviour working using the following directives in ~/.ssh/config: Host example.net ...
21
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6answers
7k views

Can I use PLink and Pageant with Cygwin's ssh?

I'm now using msysgit because of the GUI tools, which use Putty's Pageant and PLink utilities, but I use Cygwin as a general SSH terminal. I had been using ssh-agent on Cygwin, but that means I have ...
18
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2answers
3k views

Why does my OpenSSH key fingerprint not match the AWS EC2 console keypair fingerprint?

When I import my OpenSSH public key into AWS EC2's keyring the fingerprint that AWS shows doesn't match what I see from: ssh-keygen -l -f my_key It is a different length and has different bytes. ...
8
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3answers
10k views

How can I use the same key for SSH and SSL (https)

I'm trying to install the development tools for a small team, and I can't get the authentication right. Since we are a distributed team, the server is on the internet. And I'd like to have SSO+zero ...
19
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3answers
45k views

how do you create an ssh key for another user?

I'm trying to create an ssh key for another user. I'm logged in as root. Can I just edit the files generated by ssh-keygen and change root to the user I want?
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2answers
11k views

How do I set default permissions for SFTP for an Ubuntu Server?

We have an Ubuntu 10.04 server. How can I set it so that new files created (or copied) over SFTP or SSH have g+rw and g+rwx permissions (where appropriate)? I'm also using setgid (chmod g+s) so that ...
29
votes
7answers
5k views

SSH: Two Factor Authentication

I currently have a Ubuntu Server 12.04 running OpenSSH along with Samba and a few other services. At the current time I have public key authentication set up, and I'm wondering if it's possible to set ...
20
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6answers
14k views

How can I set proxy for subversion with ssh tunnel?

I want to check out/update the code via proxy since my local connection is slow. I setup ssh tunnel : ssh -D 8090 user@ssh.proxy.net to forward all the packets to my localhost:8090. How can I set up ...
15
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5answers
10k views

SSH: Do you use one private/public key pair for each remote machine? Or a single pair for all?

When you want to have public key based ssh logins for multiple machines, do you use one private key, and put the same public key on all of the machines? Or do you have one private/public key pair for ...
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10answers
17k views

DNS Name lookup (was SSH) Not Working After Snow Leopard Upgrade

I think this started with the Snow Leopard update. Cleaned out the .ssh directory, still having the issue. ~: uname -a Darwin california-example-com.local 10.0.0 Darwin Kernel Version 10.0.0: Fri ...
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4answers
2k views

SCP filename tab completion

I use SCP regularly to move files between servers and I've heard rumoured that you can use tab-completion on the remote server if you're using public keys, but so far I have had no luck. What I'm ...
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1answer
3k views

Trying to get SSH with public key (no password) + google authenticator working on Ubuntu 14.04.1

I'm using Ubuntu 14.04.1 (with OpenSSH 6.6 and libpam-google-authenticator 20130529-2). I'm trying to set up SSH logins where the public key authenticates (without a password) and a user is prompted ...
12
votes
3answers
6k views

Set up sftp to use password but ssh not to use password

Is it possible to set up a user on ubuntu with openssh so that ssh does not use password authentication but sftp does? I assume that if I change /etc/ssh/ssh_config to have PasswordAuthentication yes ...
9
votes
2answers
8k views

SSH Connections freezing with “Write failed: Broken pipe”

I am connecting to a CentOS 5.5 box via SSH from a Ubuntu 11.04 machine. The connection appears to work as expected when it is in active use (i.e. no lag or loss), but if it is left inactive for a ...
9
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2answers
5k views

How can I close SSH tunnel gracefully?

I have open tunnel with ssh -2 -N -L 5001:localhost:1019 eonil@test.local The tunnel is working good, but I have to Ctrl+C or Ctrl+D to force quit the tunnel. How can I close the tunnel gracefully? ...