the secure shell (SSH) daemon

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33 views

How do I troubleshoot ssh tunnels disconnection?

I am using SSH tunnels launched via autossh at boot on a device installed at remote locations. Up to now everything was working fine but yesterday the connection partly went down and autossh wouldn't ...
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3answers
147 views

Can't ssh to a machine

All of a sudden, I couldn't ssh to a machine to which I used to ssh earlier. Consider I am ssh-ing from A to B. Output when I run ssh root@ip_addr_of_B I get: Permission denied ...
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3answers
43 views

Redirect SSH user server side

I know that I can create shortcuts for specific users/servers on the client side via ~/.ssh/config or /etc/ssh/ssh_config, but I would like to do something similar but on the server side. That is, ...
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1answer
135 views

How to know which public key was used when someone used passwordless ssh login?

Say for some reason, there is only a "user" account on a shhd server. Everyone has his own private key to ssh to the server, as "user". Then, is there a way to see who is he (during or after his ...
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1answer
21 views

How do you verify if an INCOMING ssh tunnel is still up and who it belongs to?

See edit below for short version I am having issues displaying the status of the ssh tunnels on our server. Here is some relevant info: user001 = remote client's username 123.123.123.123 = ssh ...
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2answers
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X client forwarded over SSH “cannot open display: localhost:11.0”

I have enabled X forwarding on remote machine where SSH server is running: # grep -i forward /etc/ssh/sshd_config X11Forwarding yes # On local machine, I have started SSH client with -X flag ...
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1answer
18 views

How does ssh server defines which key to use first having more than 1?

I have just found out that on my Ubuntu machine I have more public keys to serve in /etc/ssh directory: $ ll /etc/ssh total 296K -rw-r--r-- 1 root root 237K lip 3 2013 moduli -rw-r--r-- 1 root root ...
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1answer
92 views

SSH Public Key authentication - works only after a physical login

I am trying to connect via SSH to my ubuntu server with public key authentication. For some reasons I get an "Permission denied (publickey)." on the client, whenever I execute ssh -i ~/.ssh/id_rsa ...
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27 views

sshd suddenly wants a passphrase from Linux box, but not from windows (putty)

My Amazon EC2 instance running Ubuntu is no longer letting me ssh in via my local Linux system. I haven't changed a darned thing on either side but now it wants a passphrase and says nope when I ...
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23 views

Kerberos Forwarding in SSSD

So, I'm trying to set up forwarding with Kerberos and seem to have some problems. On some of my servers I'm able to forward after receiving a ticket; however, some I'm not. My system setup is a ...
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2answers
31 views

Connect to a remote linux server that is in default setup, not configured to be connected?

In our Company we have an internal-wikipedia-like help site. The Problem is, the MindTouch-Wiki is out of date, so i have to update it! The Problem is, its running virtual. Its Ubuntu 7.7 In ...
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0answers
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pam_tacplus.so and sshd: skip user validation?

I'm trying to implement tacacs authentication on a freebsd box as a client. The box is actually a network appliance that SHOULD have this config built into its cli/ui but doesn't. Since it's built ...
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1answer
80 views

What is the maximum length of an ssh-banner message?

It seems that if the banner message is longer than a certain limit, no banner at all will be displayed to the client. What is either the character or file size limit?
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62 views

How does ssh work when client and host are on the same machine? [closed]

I illustrate my question with the help of docker containers but this example is orthogonal to the rest of the problem. In fact any program that allows the use of bridge interfaces and ssh would do. I ...
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1answer
139 views

slow ssh login to a remote machine

I am experiencing slow ssh login from a machine to a remote machine. The verbose of ssh is shown below in two broken blocks. ssh freezes for 15 seconds in the below shown block. [root@zabbix ~]# ssh ...
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1answer
83 views

sshd service is not being started: Centos 6.5

I am getting the error message below when I start the sshd service in centos 6.5. Any help to get rid of this issue? 81: GSSAPIAuthentication yes 83: GSSAPICleanupCredentials yes 97: UsePAM yes ...
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1answer
30 views

SSH key authentication works with /usr/sbin/ssh -d, does not with the daemon?

CentOS x64 6.5: if I connect as root to my server and do the following: service sshd stop /usr/sbin/ssh -d I'll able to connect as user using public key authentication from my development machine: ...
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2answers
89 views

allow only specific users to login via sshd, but refuse connect to non-listed users

I'm running a CentOS server (7.0) and I'd like to login via sshd as a user, not root. So I set PermitRootLogin no in the config file and su - after login. I've received lots of hacking activities and ...
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2answers
74 views

SSH Server on Ubuntu not works

I wanted to start SSH server on Ubuntu 14.04 running on VirtualBox. I installed Openssh, sshd, etc., configured sshd_config to listen on ip, which I see in ifconfig and it not working. I'm starting ...
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1answer
120 views

Separate SSHD Authpriv logs into /var/log/sshd, all other authpriv logging goes to messages

Right now, sshd is using the authpriv facility. The level of logging is fine, but I don't want it in the syslog, I want it to go to /var/log/sshd (which doesn't yet exist) on Red Hat Linux/Enterprise ...
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1answer
142 views

Can use Password authentication with SFTP even though “PasswordAuthentication no” in /etc/ssh/sshd_config

I have enabled SSH-keys based authentication on the Ubuntu 14.04 server, disabled root login using SSH and can connect successfully using SSH-keys based authentication with my user account blahblah on ...
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1answer
78 views

Linux: $SSH_CONNECTION is set even without SSHing to the server

I have a remote server and I am writing a script in the server and want it to fire only when I SSH. I thought of using the $SSH_CONNECTION and $SSH_TTY for this purpose. I found out that when I have ...
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2answers
89 views

Starting SSH server after VPN starts

I am running an OpenVPN server on Ubuntu 14.04 as well as OpenSSH. I have my SSH server configured to bind to an IP address on my VPN interface. Once my machine boots, binding to that IP fails. ...
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106 views

Locked myself out of Amazon EC2 SSH - This service allows sftp connections only

Doh. Locked myself out of SSH on an Amazon EC2 box after fiddling with ForceCommand internal-sftp in /etc/ssh/sshd_config in order to allow root log-in via SFTP. SFTP still works fine, but PuTTY ...
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3answers
33 views

Is there a log for sshd where I can see who has used ssh to access my PC? [duplicate]

I am running the OpenSSH daemon (sshd) on CrunchBang Linux, and I want to see a history of who (i.e. IP address) has logged in using SSH.
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1answer
25 views

CentOS 6.4: SSH RSA key issue, “[…]== rsa-key-20140711\n failed”

For some reason sshd is reading from my authorized_keys file a new line that does not exist. I generated the keys with puttygen, copied the public key text in as required, concatenated the key into ...
3
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1answer
60 views

SSHD Password Feedback (Show Asterisks for Characters)

Is it possible to have SSHD show asterisks for the password characters much like pwfeedback does for sudo? I am using CentOS 6.5. For example:
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1answer
58 views

SSH slow after configuring TCP Wrappers

We have SSH open on one of our production servers leaving it prone to various brute force attacks to break in. I reduced the attempts by changing the default port from 22. I want to further harden ...
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0answers
131 views

SSH AuthorizedKeysCommand and SELinux

I'm trying to use the SSH AuthorizedKeysCommand in a CentOS 6.5 machine, but I'm encountering an SELinux error. When I switch SELinux to permissive mode - using setenforce 0 - it works, but when I ...
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2answers
342 views

What is the difference between these two SSHD configs?

1 Match Group GROUPNAME, User *,!root 2 Match Group GROUPNAME User !root My question: What is the difference between #1 and #2 in the SSHD_CONFIG?
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Unable to SSH into Puppy Linux, even though SSHD is running

I installed OpenSSH client and server on my Puppy Linux computer. That computer is behind a router. I tried to ssh into it over the internet (outside the router) but it times out. Also doesn't work if ...
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237 views

X11 connection rejected because of wrong authentication — on CentOS, for all users (including root)

I'm configuring a small computing cluster with CentOS. The last step is setting up X11 forwarding, and here I find problems that I cannot solve. On all compute nodes except one, I can set up ...
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1answer
62 views

How to exclude from a “Match Group” in SSHD?

There is a Match group in the SSHD config: cat /etc/ssh/sshd_config ... Match Group FOOGROUP ForceCommand /bin/customshell ... There are many users on the machine that are in the ...
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2answers
629 views

MaxStartups and MaxSessions configurations parameter for ssh connections?

I am copying the files from machineB and machineC into machineA as I am running my below shell script on machineA. If the files is not there in machineB then it should be there in machineC for sure ...
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3answers
1k views

Use SSH key authentification with custom user $HOME

I have some users which have different $HOME directories than /home/... The user homes are under /pkg/homeand /pkg owner is a different user but all users have group access to /pkg. But it seems ...
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60 views

Centos not respecting ClientAliveCountMax

I'm running Centos 6.3 and trying to connect to it via OS X through capistrano deploying a Rails project. Capistrano is notorious for not respecting ServerAliveInternal from the client so I must set ...
2
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1answer
63 views

Is there a way to run a privileged command upon successful SSH login (not necessarily with shell or PTY)?

I'd like to run a privileged command upon successful SSH logins at the server's end. However, this has to be in the server configuration (sshd_config or anything else that cannot be manipulated or ...
1
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1answer
228 views

problem with unique ssh public/private key pair on second user

I have created an ssh key pair using ssh-keygen -t rsa for my main user and everything seems to be working well. Password login has been disabled. I have a second user that I am trying to create a ...
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1answer
1k views

How can I restart the SSH daemon on Ubuntu?

When I type in service sshd restart I get a sshd: unrecognized service error. I do have, in /etc/ssh/ a file sshd_config that I use to set config. I can also putty into the Ubuntu box (it is remote). ...
1
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1answer
44 views

How to fix SSH on OSX?

I have been able to connect to OSX machine using ssh client successfully for hours, but then it stops working and I get connection refused. ps -ax | grep ssh 841 ttys004 0:00.00 grep ssh Using ...
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1answer
240 views

Login via ssh without password, getting authorized_keys file removed after first login attempt

I'm trying to configure passwordless login via ssh. I have Centos 6.5 This what I did: copied content of id_rsa.pub from my client machine to ~/.ssh/authorized_keys set permissions 700 to ~/.ssh and ...
2
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1answer
109 views

rkhunter /usr/bin/ssh && /usr/sbin/sshd [Warning]

My last rkhuter scan reported a couple of warnings that deserve to be checked(for my noob eyes). Main reason for my suspect is that i wasn't on the machine at (03-Apr-2014 01:12:12) ->AM I googled ...
4
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1answer
50 views

Seperate messages of multiple sshds in syslog-ng

Is there a common way of distinguishing between the messages of multiple processes in syslog-ng beside setting different facilities? +1 if filtering and therefore logging in different files would be ...
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0answers
46 views

Are there any canned solutions for running sshd in the initrd?

This is mostly aimed at Debian/Ubuntu, but I feel savvy enough on a variety of distros to be able to adapt the solution for one distro to another. Here's my scenario. There are a few situations when ...
3
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1answer
48 views

Accept any private key for authentication

Is it possible to configure OpenSSH (or any other standard sshd) to accept any key offered by a connecting client? EG ssh -i ~/arbitraryKey hostname grants a login shell while ssh hostanme doesn't. ...
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1answer
388 views

Logging ssh remote commands to `bash_history`

SSH allows a remote user to issue some command without interactively logging in to the server, as the last line of ssh usage indicates: usage: ssh [-1246AaCfgKkMNnqsTtVvXxYy] [-b bind_address] [-c ...
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1answer
1k views

How to resolve ssh connection refused on AIX?

I am no longer successfully able to connect to my AIX LPAR. ssh -v user@<ip> OpenSSH_6.2p2, OpenSSL 1.0.1c 10 May 2012 debug1: Reading configuration data /etc/ssh_config debug1: Connecting to ...
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3answers
4k views

Where are my sshd logs?

I can't find my sshd logs in the standard places. What I've tried: Not in /var/log/auth.log Not in /var/log/secure Did a system search for 'auth.log' and found nothing I've set /etc/ssh/sshd_config ...
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1answer
174 views

ssh connection fails after login at one user

Have server with 2 users - (e.g. - user and root). SSH login to root works corrctly. But I can't login to user - it immediatelly fails with "write failed - broken pipe" after login. ssh -vvv ...
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1answer
591 views

How can I have a SSH banner appear BEFORE the “login as:” prompt? [duplicate]

CentOS 5.x When I enable the Banner /path/to/banner parameter in my sshd config file, the banner displays AFTER the login as: prompt. For example: login as: foo ...