the secure shell (SSH) daemon

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2
votes
1answer
18 views

Display full settings of sshd

The OpenSSH daemon has many "default" values for its settings. So looking at the sshd_config might not give someone the complete set of active settings. How to display the full sshd configuration ...
7
votes
1answer
113 views

Blocking SSH Brute Force attacks on IPv6

I recently had to work with some servers that have an IPv6 connection and I was surprised to find out that fail2ban does not have IPv6 support, neither does denyhosts. Searching on google I found that ...
0
votes
1answer
33 views

Configure ssh users under a group [closed]

I created a group called ssh_group and currently have nearly 20 users under AllowUsers in /etc/ssh/sshd_config. After I created the ssh_group, I modified the AllowGroups line like this AllowGroups ...
1
vote
2answers
120 views

remote shell - are there any non-ssh based alternatives?

Are there any alternative SSH servers other than SSHD? One that is not SSH based? Ideally one that can be installed from offical Debian repository, that listens on a port other than port 22. (To ...
0
votes
1answer
24 views

Adding user override to sshd_config causes ssh_exchange_identification error

I wanted to allow SSH TCP forwarding for a specific user, so I added this section to sshd_config: Match User rainmannoodles AllowTcpForwarding yes TCPKeepAlive yes After that change, I get ...
0
votes
0answers
27 views

SMTP traffic being forwarded through SSH even do AllowTcpForwarding is disabled

I have a situation on one server, where it seems to be spaming over traffic being sent over SSH tunnel. Output below shows connections being made to remote SMTP server that seem to be initiated over ...
1
vote
1answer
164 views

CentOS 7 - ssh login is refused when i use ssh public key, but only works with username password

I am not able to login via SSH key. I place my id_rsa.pub key in the /root/.ssh/authorized_keys [root@s .ssh]# ll total 4 -rw------- 1 root root 403 Jun 8 00:44 authorized_keys [root@s ~]# cat ...
0
votes
1answer
613 views

How to start sshd on Puppy Linux?

I have installed sshd on puppy linux. Can someone tell me how to start sshd on it?
1
vote
1answer
4k views

Forwarding X11 not working - Error: Can't open display: localhost:11.0

LM 17 Xfce OpenSSH_6.6.1p1 Ubuntu-2ubuntu2 Despite googling everywhere, I cannot seem to get this to work. I keep getting this error. $ xlogo Error: Can't open display: localhost:10.0 I have tried ...
2
votes
1answer
21 views

Use two SSH ports, but open only one?

My iptables.conf looks loosely like this: -A INPUT -p tcp --dport 65000 -j ACCEPT -A INPUT -j DROP My sshd_config looks like this: Port 22 Port 65000 #AddressFamily any #ListenAddress 0.0.0.0 ...
2
votes
0answers
30 views

Two ISP and redirecting traffic

I have a gateway with two ISP connected to eth0 and eth2. There is also a eth1 with local network. I'm trying to group some services in one interface and some in the second: incoming traffic 1 ...
2
votes
2answers
106 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 ...
3
votes
1answer
1k 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) ...
3
votes
3answers
90 views

How to start SSH daemon on boot on Linux Mint Debian v2

I'm using Linux Mint Debian v2, 64-bit. I noticed recently that my ssh daemon does not start automatically on boot. It used to. I'm not sure if it had to do with my UFW configuration or sshd_config ...
0
votes
1answer
2k views

CentOS 7 add new user with root privileges

I am reading this tutorial, and trying to create a new user with root privileges and then block root access via ssh in a CentOS 7 server. The problem is that the new user is blocked from doing root ...
16
votes
2answers
2k views

SSH ignores characters after correct password string?

Remote machine 10.10.10.1 has password "asdFGH12" for user named "user". I'm able to log in even if I type in password "asdFGH12dasdkjlkjasdus" or any other characters after the "asdFGH12" string. $ ...
2
votes
3answers
13k views

sshd_config MaxSessions parameter

I have problem with "MaxSessions" parameter in sshd. I would like to restrict number of sessions via one ssh connection. For example for tcp forwarding. When I set MaxSessions to 0, logons are not ...
0
votes
0answers
65 views

xterm Xt error: Can't open display: localhost:11.0

I'm on a windows machine running Xming32, putty and plink. I have two centos boxes. One I can connect to just fine. The other I can't. I'm trying with this command plink -C -v jdearing@BROKENHOST ...
3
votes
1answer
32 views

sudo command inside heredoc block in a ssh session is not working

When i use heredoc and put all the commands inside heredoc as, ssh -t -i master.pem cloud-user@$1 <<EOSSH sudo service x restart sudo service y restart EOSSH it throws error as, ...
1
vote
1answer
57 views

How to ensure ssh via cgroups on centos?

When some cpu-intensive processes are running on the server, chances are that we could not log in to this machine with error 'operation timeout' via ssh command. According to this post answered by ...
2
votes
1answer
41 views

Is sshd_config TPCKeepAlive still using unencrypted channel and therefore vulnerable

This post from 2008 in ubuntuforums recommends disabling TCPKeepAlive Disable TCP KeepAlive messages. These messages are spoofable and are sent outside of the encrypted channel, and ...
4
votes
5answers
108 views

Multiline Text Processing : Editing sshd_config

I have multiple blocks at the end of my sshd_config files like theses: Match User FOO ChrootDirectory /srv/www/FOO AllowTCPForwarding no X11Forwarding no ForceCommand internal-sftp ...
4
votes
1answer
69 views

Uselogin in sshd_config

I was looking through my sshd_config file and I found this: #Uselogin no I know it's commented but there is no explanation above it and when I google it, I get this: Don't use the traditional ...
2
votes
3answers
453 views

Authentication refused: bad ownership or modes for file /var/git/.ssh/authorized_keys [duplicate]

EDIT The issue as exposed here is solved (about files modes of the .ssh folder. But an other issue persists so I create a new question : > Unable to login with SSH-RSA key I can no longer ...
0
votes
1answer
53 views

Unable to login with SSH-RSA key

This post is following this question : Authentication refused: bad ownership or modes for file /var/git/.ssh/authorized_keys . The issue as exposed there is solved (about files modes of the ...
25
votes
2answers
61k 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). ...
2
votes
0answers
62 views

How to tell systemd to start sshd later in the boot sequence?

My sshd_config file specifies it should listen on some specific IP addresses instead of on all IP addresses. The problem is that one of these NICs doesn't come up until later in the boot sequence. ...
2
votes
1answer
47 views

Configure OpenSSH server not to require password *or* key for a particular user

For the purpose of a training session, I'd like to make it possible for a particular user to connect without requiring a password or key-based authentication. I do not know the IPs or other data of ...
2
votes
2answers
95 views

Passwordless login only works using directly invoked sshd on server

I've been through as many of the bugfixes as I can find for the classic ssh key issue : I've set up my public and private keys "correctly" but passwordless login still doesn't work. The details : ...
2
votes
2answers
3k 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 ...
0
votes
0answers
54 views

fedora 21 workstation and sshguard 1.5 set up

I installed fedora 21 workstation, and I compiled and implemented sshguard 1.5 since I could not find rpm 64. How do I best set up sshguard so that it protects the server? Esp. in terms of reading the ...
0
votes
1answer
111 views

SSH login too slow in Centos 6.6 [closed]

SSH login take too much time in my CentOS machine, and also a ftp server is running on it. Please help me to speedup the login time for both root and ftp user. I tried some tricks but no ...
1
vote
1answer
72 views

Can't connect to the sshd in my unprivileged LXC guest. What to do?

So you configured your unprivileged LXC guest, by defining lxc.id_map = u 0 1000000000 10000 lxc.id_map = g 0 1000000000 10000 and of course assigning those subordinate UID/GID ranges to an ...
4
votes
1answer
11k views

installing fail2ban on CentOS 7

I am using @GarethTheRed 's answer to this question to install fail2ban on a remote CentOS 7 server. I am able to complete all the steps up until tail -f /var/log/fail2ban.log, at which point I get ...
1
vote
1answer
136 views

Is there a canonical method to restrict ssh access to certain IP addresses in Unix?

I checked man pages related to ssh on OS X and other systems and tried using hosts.allow and hosts.deny files as per this post, and sshd_config to no avail. $ cat /etc/hosts.allow sshd: ...
2
votes
1answer
37 views

SSH demon not installed in linux embedded device

I have an embedded device which runs linux(arm). I am trying to update the executable through ethernet using scp command. But I got to know that sshd is not running in the device . I need to install ...
0
votes
0answers
51 views

How do I configure SSHd to require 2 (or more) passwords to log in

I'm asking because I want to setup a server that cannot be administered by any single admin, not without the permission (and oversight) of one other authorized admin (there can be many). Since there ...
2
votes
1answer
1k views

Key-based authentication from PyCharm / JSCH to OpenBSD fails

I am trying to configure PyCharm (java-based IDE) to connect via sftp to a new OpenBSD 5.6 machine with an almost-default setup. However, it keeps returning an error "Algorithm negotiation fails". I ...
2
votes
1answer
40 views

Are there any loopholes in IP restricting sshd?

Say that i want to only allow username/password logins on my private network, but restrict all external sources on to key/cert login. I would do something like this: RSAAuthentication yes ...
0
votes
1answer
51 views

how to view failed login attempts?

I tried to view failed user login attempts since a specific time. But all methods I found by searching the internet does not work. I am using openSUSE 13.2. journalctl -a --no-pager ...
2
votes
2answers
700 views

RHEL 7 (CentOS 7) security / ssh / sshd_config advise requested

I am not a sysadmin and try to create a more or less secure web server (LAMP based CentOS 7). I read several tutorials about setup an initial CentOS 7 droplet and got everything running fine. ...
2
votes
1answer
72 views

How to make sshd listen to two ports, but restrict one of them to a single source address?

I need sshd to listen both on port 22225 (allowing connections on that port from any IP) and port 22 (allowing just a single static IP on that port). In other words, listen on two ports at the same ...
0
votes
0answers
43 views

ssh agent-forwarding with lxc

I have a "little" problem I try to ssh using putty and pageant to server, than to ssh into lxc-container and than to other server. But no publickey is used, it prompts for password (at last hop). ...
2
votes
1answer
137 views

How to use ssh over http or https?

I have a linux fedora21 client laptop behind a corporate firewall (which lets through http and https ports but not ssh 22) and I have a linux fedora21 server at home behind my own router. Browsing ...
0
votes
1answer
23 views

Set MasSessions to SSH does not take effect

I got a server with enabled ssh. To prevent attacks and to fit to my needs, I just need one connection at the same time to my server. So, I tried to set MaxSessions paramater to 1 in ...
2
votes
0answers
173 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 ...
0
votes
1answer
2k views

How to open the SSH port 22? [closed]

I have installed the ssh utility on an embedded system but I can't connect to it. I am able to ssh from the device to another computer on the network but not the other way around. The only port ...
4
votes
1answer
396 views

Why did sshd delete my /dev/zero?

When I do lsof +c 0 | grep /dev/zero, I see the following two lines: sshd 19064 root DEL REG 0,4 497862 /dev/zero sshd 19064 root DEL REG 0,4 498725 /dev/zero ...
1
vote
1answer
117 views

Restrict SSH login to local network: VPN connection not allowed

There are two (unix) users who are allowed to connect to my Debian Wheezy server using ssh: git and peter. While git is allowed to connect from everywhere, peter (who is in the sudo group) should be ...
0
votes
2answers
202 views

SSH banner not showing

I have a fresh installation of OpenSSH. In the /etc/ssh/sshd_config I have the following entry: Banner /etc/issue.net I have restarted the SSH deamon using: sudo /etc/init.d/ssh restart. Now, ...