5
votes
1answer
59 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 ...
0
votes
3answers
26 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.
1
vote
1answer
13 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 ...
1
vote
2answers
71 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 ...
1
vote
1answer
31 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 ...
2
votes
0answers
51 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 ...
0
votes
0answers
37 views

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 ...
1
vote
2answers
154 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 ...
0
votes
0answers
21 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 ...
1
vote
1answer
59 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?
1
vote
1answer
108 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 ...
1
vote
1answer
38 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 ...
1
vote
1answer
153 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
votes
1answer
81 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 ...
2
votes
1answer
587 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 ...
1
vote
1answer
106 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 ...
1
vote
2answers
64 views

can I tell to useradd to execute a script? Maybe in /etc/default/useradd?

There are plenty of people that already answered to the question "how to execute useradd properly in a script?" My question is: "is it possible to tell to useradd to execute one script when it is ...
5
votes
1answer
3k views

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 ...
3
votes
0answers
31 views

unable to forward X11 applications [duplicate]

I installed a headless Debian server which has Wireshark installed. Now I would like to run Wireshark in a way that it uses X11 server running in my Linux Mint laptop. As a first step I permitted X11 ...
4
votes
2answers
449 views

How to Provide login delay in ssh

I wanted to provide login delay while login through ssh .I tried couple of ways of doing same but couldn't find desired result. I tried steps provided by given link. ...
4
votes
1answer
227 views

Executing a remote command on SSH connection, before login

I am trying to find a way to execute a specific command when connecting to a server via SSH. By this I mean, the command will execute unconditionally on opening a connection, so this would preferably ...
0
votes
3answers
330 views

What are the commands to apply changes made to /etc/ssh/sshd_config?

I have made some changes to /etc/ssh/sshd file and wanted these effects should take place. I know I can run below command for the effects to take place. /etc/init.d/sshd reload But on my box I ...
2
votes
1answer
209 views

How to terminate an interactive ssh session after certain amount of time

In my /etc/ssh/sshd_config file I have set the below parameters: ClientAliveInterval 10 ClientAliveCountMax 3 Now from host machine I did ssh to the my server (where I made changes to ...
0
votes
2answers
672 views

SSH client authentication as non root user

On my system ssh client authentication was allowed for root, but I wanted ssh client authentication to be allowed only for non root users. To disable ssh as root, I changed the PermitRootLogin yes to ...
1
vote
1answer
232 views

Reverse connection to SSH server [duplicate]

Machine A is connected to the internet and is behind firewall so it cannot receive incoming connections. Machine B is open to the internet. I want to be able to type commands into B and have them ...
1
vote
1answer
124 views

failure in connecting to my server through ssh

My goal: I want to be able to ssh to my workstation from external client. My workstation(in the following also referred as server) is on a lan. Its ip address on this lan is obviously different from ...
1
vote
2answers
611 views

Disable ssh banner for specific users or ips

I've enabled the banner that appears before the password prompt by setting it it sshd_config. However certain users (especially me) really don't need to see the banner (it also screws up a lot of ...
8
votes
4answers
590 views

Failing to block brute force ssh with iptables

I'm trying to block (slow down) brute force attacks on my sshd server. I'm following this guide http://www.rackaid.com/resources/how-to-block-ssh-brute-force-attacks/ which basically says I need to ...
1
vote
2answers
103 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 ...
5
votes
1answer
127 views

hosts.allow: %u not working (log username)

I need to keep track of all SSH connections on my server. In my /etc/hosts.allow I have something like this: sshd: ALL : spawn ( echo "`date` from %u %a " >> /var/log/ssh/%d.log ) & where ...
5
votes
2answers
6k views

What do the channel numbers in ssh error message refer to?

In the example below what do the channel numbers correspond to? Which are on the server? Which are on the client? $ ssh -L1570:127.0.0.1:8899 root@thehost Password: Last login: Fri Aug 9 ...
1
vote
2answers
150 views

Unable to force passphraseless ssh authentication while port forwarding

I'm completely at a loss as to what is preventing my local machine from authenticating the connection that is being forwarded from the remote server. I've read a ton of the posts on here regarding ...
3
votes
1answer
490 views

Public-Key Authentication w/ Jailed SFTP User

I'm trying to set up a jailed SFTP user account on my own local machine to test an application with libcurl. I used this guide to help me figure out how to set up a jailed SFTP user: ...
1
vote
1answer
2k views

iptables prevents connection via ssh after port change despite ACCEPT rule

I have two machines hooked up to a router, one Windows with PuTTY, and one CentOS 6.4 with sshd and with the default SELinux still enabled. They can both ping each other successfully. I installed ...
4
votes
1answer
747 views

My reverse-ssh tunnel is using keepalives but they're not helping

I have an ssh client machine picard behind multiple unreliable internet connections - all with NAT. I have my server time, reliable with a static IP. I want to be able to access picard thorugh time. ...
1
vote
1answer
147 views

How to prevent ssh-agent from starting in CentOS?

How do I stop ssh-agent from starting when logging into CentOS via openssh? There are no references to ssh-agent in my bash startup scripts (.bashrc) or /etc/bashrc.
1
vote
1answer
186 views

Why is sshd looking at a non-existent public key file?

In an effort to get SSH keys working I'm tailing the sshd authorization log and I see these lines: debug1: test whether pkalg/pkblob are acceptable debug1: temporarily_use_uid: 10144/10029 (e=0/0) ...
2
votes
1answer
138 views

ssh-add -D doesn't erase stored keys from the ssh-agent

How come this happens?: stan@tcpc:~/.ssh$ ssh-add -l 8192 e0:45:5e:cc:45:3e:17:2b:a6:54:6f:8d:53:1b:j2:e3 github (RSA) 2048 25:41:53:a6:45:5d:ac:eb:5c:45:f8:ce:42:a9:he:aa BITBUCKET (RSA) ...
12
votes
5answers
642 views

what's the purpose of ssh-agent?

I've read the official definition: ssh-agent is a program to hold private keys used for public key authentication (RSA, DSA, ECDSA). The idea is that ssh-agent is started in the beginning of an ...
2
votes
3answers
1k views

How to limit ssh access for localhost only?

I need to forbid ssh access (except localhost) for specified user. So. ssh localhost should work. ssh hostname from outside should not work for that user. All other users should work as usual.
2
votes
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 ...
5
votes
5answers
552 views

How to setup password-less ssh with RSA keys

I am trying to setup a password-less SSH configuration between two machines and am having trouble. There are a ton of howtos out there that I have followed and have had no success. Here are ...
5
votes
4answers
857 views

ssh command unexpectedly continues on other system after ssh terminates

I'm running the below command, and monitoring the output file on the other system: ssh $ip_address 'for n in 1 2 3 4 5; do sleep 10; echo $n >>/tmp/count; done' If I kill the ssh command ...
2
votes
1answer
492 views

How can I tell if sshd is running with ClientAliveInterval > 0?

The title pretty much says it all, I'm a user on a system, and I want to know if that system is running sshd with a ClientAliveInterval > 0, which would tell me if I need to worry about using ...
16
votes
1answer
19k views

How does tcp-keepalive work in ssh?

I am trying to code a shell-script that uses a ssh-connection for doing "heartbeats". I want to terminate the client- and server-side of that connection after a certain timeout (after the connection ...
1
vote
2answers
4k views

Change default path for when I SSH in to CentOS server?

I have a CentOS 5.7 web server, and I want to change the default place I land in when connecting using SSH. Currently I land in /home/username, and I want to land in /home instead. I've gone in as ...
2
votes
1answer
245 views

Why doesn't my new cygwin .bashrc interactive check work?

I just updated Cygwin and the new .bashrc contains this line right at the top: echo "BEFORE TEST" # If not running interactively, don't do anything [[ "$-" != *i* ]] && return echo "AFTER ...
3
votes
3answers
414 views

How to install openssh in Crux Linux

In Crux Linux I already have installed SSH but when I use ssh-keygen, and try to use the command: ssh localhost to test SSH I get this error: # ssh localhost ssh: connect to host localhost port ...
3
votes
1answer
1k views

Can sshd restrict client tunnel endpoints to localhost?

Normally an ssh client can request TCP forwarding using the -L command line option. The server can disable this completely using AllowTcpForwarding no. If enabled, the client can request to connect ...
3
votes
4answers
213 views

Internet SSH Server Security Considerations

What steps should I take to reasonably secure my linux desktop before opening sshd to the Internet so I can connect from anywhere?