the secure shell (SSH) daemon

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4
votes
1answer
319 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 ...
1
vote
2answers
3k 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
130 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
votes
1answer
143 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
vote
1answer
94 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?
9
votes
1answer
19k 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
vote
1answer
64 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
989 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
279 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
votes
1answer
61 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 ...
3
votes
0answers
63 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
votes
1answer
69 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. ...
2
votes
1answer
3k 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 ...
5
votes
1answer
1k 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 ...
1
vote
1answer
270 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
1answer
2k 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 ...
2
votes
1answer
92 views

Unable to connect after ChrootDirectory within sshd_config

After adding the following to my sshd_config file... Match user myuser ChrootDirectory /var/www/html X11Forwarding no AllowTcpForwarding no ForceCommand internal-sftp I am unable to ...
0
votes
1answer
251 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 ...
2
votes
1answer
3k views

Activity Logging Level in SFTP

I'm using CentOS, i have already figured out how to enable the SFTP Logging. After that when i test it by using FileZilla (from User-end) and tail -f /var/log/sftp.log from the Server, all the ...
2
votes
1answer
62 views

How to prepare a headless machine?

I'm currently preparing an SD-card for my Raspberry Pi, i.e. an ARM machine, while I'm sitting on a x86 one. Therefore I cannot simply chroot into it and run rc-update add sshd default. So, how else ...
2
votes
3answers
17k 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 ...
1
vote
2answers
139 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 ...
3
votes
1answer
309 views

Reconfigure login through root ftp (lost ssh access)

My question is twofold. I need to somehow re-enable telnet and/or ssh in a device where I currently only have root ftp access. Also, if I am going about this wrong, please let me know. Details to ...
3
votes
2answers
4k views

Why does sshd requires an absolute path?

Why does sshd require an absolute path when restarting, e.g /usr/sbin/sshd rather than sshd Are there any security implications? P.S the error message: # sshd sshd re-exec requires execution with ...
2
votes
0answers
181 views

telneting to ssh port works, but SSH not

I installed a machine with two network cards: one goes in the router, gets IP via DHCP, OK, another is connected to my notebook directly, using a different IP subnet. I can ping both IP addresses, ...
6
votes
2answers
18k 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
32 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 ...
2
votes
1answer
155 views

SFTP chroot jail/access based on wildcard

I want to give a list of people SFTP access to /webdocs/ABC* where they will read-write access to only directories that match this wildcard. How do I do this? Can I create a chroot jaill or some ...
5
votes
2answers
1k 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. ...
2
votes
1answer
293 views

Why “sshd Bad prime description” errors?

I've noticed that all our FreeBSD machines throw sshd Bad prime description in line xxx (insert a large number of values for xxx). Presumably this is not something they are all supposed to be doing ...
4
votes
1answer
412 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
739 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
343 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 ...
2
votes
0answers
149 views

SSH server is not disconnecting session when I shutdown the machine

I have a Arch Linux virtual machine, if I shutdown the machine while a ssh connection is alive. The SSH session would stuck (and the machine shuts down correctly) So the server is not disconnecting ...
2
votes
1answer
325 views

How to dump SSHD process and search for strings

Symantec has disclosed details on an SSHD backdoor and suggests to dump the SSHD process and search for some particular strings. NOTE: Background here: Symantec report on Linux Back Door I have no ...
0
votes
2answers
2k 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
404 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
159 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 ...
3
votes
2answers
2k 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
940 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
945 views

installing/configuring and running sshguard on debian

I am trying to install/configure and run sshguard on debian, I want to check if brute force attacks happen on my server. I have installed it via apt-get, then I installed systemd and followed the ...
1
vote
3answers
237 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 ...
3
votes
2answers
103 views

Why does SSH hosts keys differ when connecting if the host_keys are the same?

There are 3 machines: A (from where I connect to B and C), B, and C. B and C have the same SSHD host keys (they have been copied, so they are 100% the same, SSHD has been restarted too, identical ...
4
votes
1answer
158 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 ...
0
votes
2answers
572 views

How many authorized_keys can/should be set up in SSHD?

I'm following a FreeNX install wiki page for ArchLinux. Right now I'm setting the SSHD parameter for "AuthorizedKeysfIle". And this brings up the question, How many authorized_keys can/should be set ...
7
votes
2answers
10k 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
280 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
636 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
3k 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 ...
0
votes
2answers
103 views

How to test that X11Forward is working or not?

X11Forwarding yes was enabled and sshd reloaded. But how can I test that X Forwarding works or not? xclock is not installed. Perl and python-base is installed, are there any tricks ex.: pop-up a GUI ...