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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SSH Connection Silently Dies

As the title says I'm having a very strange problem with SSH connections at my house, it seems that after about 3-5 minutes of inactivity any SSH sessions I have open will just shutdown and leave the ...
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1answer
544 views

Cannot connect to ec2 instance

I've created a new ec2 instance based on the php cloudformatino image ami-6fc2f61b and attached my existing key to it. Security group allows ssh and http. Yet, I'm unable to connect: $ ssh -v -i ...
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1answer
248 views

SSH directly “through” another server [duplicate]

Possible Duplicate: How to configure a shortcut for an SSH connection through a SSH tunnel Multiple networks I can connect to have the following set up. There is a single node that can be ...
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5answers
2k views

ssh access without password

I know that it is possible to ssh to another server without a password if authentication keys are set on both the servers. But I will like to know if it is possible to allow users from any IP ...
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2answers
259 views

Can I overwrite a setting within sshd_config with a duplicate setting

I am implementing a basic deploy script and for sshd_config the only change that I need to make is PermitRootLogin yes to PermitRootLogin without-password. I have read through the docs and they make ...
0
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1answer
537 views

Managing SSH keys for multiple users for multiple systems (ie github like ssh key ui)

So we are trying to lock down our systems to be accessed only by a few logical users (users on the Linux machines) but many physical users. That is all the developers can login as user dev with their ...
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3answers
2k views

How to tell if a public SSH key has a passphrase

This is probably a noob question, but how can I determine if the public SSH key someone gives me has a passphrase or not? We have a situation where I am not generating the SSH keys for users, but I ...
9
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12answers
20k views

ssh session idle timeout

The Solaris machine we do most of our development on has an annoying habit of timing out SSH sessions. Doesn't matter whether the client is my Ubuntu desktop, my Solaris desktop or my Windows desktop ...
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1answer
563 views

Random SSH entries in Auth.log out of date order [duplicate]

Running an Ubuntu Trusty 14.04.1 LTS server at Rackspace but recently after running updates for bash, then with the reboots for the xen host vulnerability, I have the following weird issue. Some ...
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1answer
1k views

Intermittent ssh_exchange_identification: Connection closed by remote host

We encountered an issue where a series of git requests over ssh would sometimes fail with ssh_exchange_identification: Connection closed by remote host There are many examples on SE/SF of structural ...
4
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1answer
219 views

Allow SSH only on one of a servers IP addresses

I have a server with several IP addresses that hosts sites on each IP address. I have one ip address that does not have a site associated with it. I want to allow SSH login only to the one IP address ...
4
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1answer
6k views

sshd warning, “POSSIBLE BREAK-IN ATTEMPT!” for failed reverse DNS

Whenever I SSH somewhere I get something like this in the logs: sshd[16734]: reverse mapping checking getaddrinfo for 1.2.3.4.crummyisp.net [1.2.3.4] failed - POSSIBLE BREAK-IN ATTEMPT! And it ...
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1answer
1k views

Shared Cygwin Install

I'm attempting to set up OpenSSH on a bunch of Windows Server 2003 machines in an automated fashion. My goal is to be able to do so using a single version of Cygwin installed on a network drive ...
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2answers
2k views

rsync via multiple ssh connections with a key

I need to do a rsync from a target server with a server in the middle and I have the same public key on both the target and middle server. I want to use that key so I don't have to do password ...
4
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3answers
2k views

set up a chrooted SFTP login with OpenSSH

How might I create an SFTP login for an untrusted user in which he can only access the files in his own home directory and not run any commands? The online tutorial OpenSSH SFTP chroot() with ...
3
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2answers
933 views

Getting hostname of the computer connected to the ssh session

As part of our deployment script for one of our apps I'm trying to log the date, time, and other relevant information for the deployment. The way we have it set up, developers use a generic "app" ...
3
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1answer
1k views

Increasing permissiveness/permissions for umask + openssh + chrooted SFTP server using internal-sftp

The suggestion found at these links works for me: How to setup ssh's umask for all type of connections http://ubuntuforums.org/showthread.php?t=1107974#5 Summary: Use PAM to inject the umask, ...
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1answer
2k views

10 second SSH delay prior to successful login [duplicate]

Possible Duplicate: ssh delay when connecting I have a Scientific Linux virtual guest running out of Virtualbox 4.0.4 on an Ubuntu 11.04 machine. When I SSH from the host to the guest, ...
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5answers
5k views

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
22k views

Gitlab not working with SSH Keys

I am having issues with Gitlab. I used the following guide to install and configure Gitlab https://github.com/gitlabhq/gitlab-recipes/blob/master/install/centos/README.md. The installation seemed to ...
2
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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, ...
2
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2answers
17k views

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
4k 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
303 views

SSH locale wrong

I have a debian server with locales set to hu_HU.UTF-8, and if i log in trough console it works perfectly in hungarian. It also worked with ssh logins until i disabled PAM in the sshd config. Since ...
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0answers
522 views

ssh reverse tunnel port forwarding connection fails

I am able to do a reverse port forwarding through the PUTTY GUI with settings similar to below. Once I apply this setting, I am able to run to the server box and run wget http://localhost:8080 <-- ...
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1answer
2k 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
295 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
171 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
6k 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
512 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
979 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 ...
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2answers
1k 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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2answers
1k 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 ...
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1answer
14k 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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3answers
1k 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 ...
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1answer
415 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 ...
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0answers
682 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
162 views

Override SSH message when accessed via HTTP

If you access my server via HTTP using the SSH port (22), you'll see a message like this: SSH-2.0-OpenSSH_5.9p1 Debian-5ubuntu1.1 Could be possible to display a different message?
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2answers
311 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 ...
128
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2answers
40k 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?
37
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4answers
55k 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 ...
48
votes
12answers
25k views

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 ...
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10answers
13k 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 ...
80
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3answers
42k 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/ ...
29
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7answers
86k 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 ...
64
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1answer
43k 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 ...