Stack Exchange Network

Stack Exchange network consists of 175 Q&A communities including Stack Overflow, the largest, most trusted online community for developers to learn, share their knowledge, and build their careers.

Visit Stack Exchange

Questions tagged [openssh]

Questions about the OpenSSH implementation of the ssh protocol.

0
votes
0answers
21 views

Port scanning test at a library

So I am trying to teach myself some basic networking skills. I dont have wifi at home so i frequently use public wifi. I am trying to ssh into my android phone so i can run commands remotely and be ...
0
votes
0answers
47 views

CentOS7 OpenSSH won't start with machine and hangs when ran via systemctl

The SSHD service is enabled on my VM, however it does not start when the machine boots. Further, if I run systemctl start sshd it simply hangs. If I manually run /usr/sbin/sshd, it starts no problem ...
0
votes
1answer
21 views

If you ssh to another device in your LAN, can you accidentally connect through a less direct pathway (WAN)?

My question regards ssh, sftp, scp, rsync, etc. commands where you connect to another machine which can be in your Local Area Network (LAN) or at some remote location you would typically connect via ...
1
vote
0answers
40 views

How to send traffic to a specific IP address via a specific interface?

On a Debian Stretch VM (running in VirtualBox on a Windows 7 host), I would like to connect via SSH to a specific remote host (let's call it myServer, with IP 12.34.56.78). To do so, I'm using my ...
0
votes
0answers
40 views

upgrade openssh rpm error: unpacking of archive failed on file /usr/bin/ssh-keygen: cpio: rename failed - Permission denied

rpm -Uvh openssh-5.3p1-124.el6_10.x86_64.rpm openssh-server-5.3p1-124.el6_10.x86_64.rpm openssh-clients-5.3p1-124.el6_10.x86_64.rpm openssh-askpass-5.3p1-124.el6_10.x86_64.rpm warning: openssh-5.3p1-...
1
vote
1answer
32 views

Run command on SSH server whenever a user connects, even if just for tunneling

I'd like to, as the administrator of an OpenBSD ssh jumphost used by multiple people, run a specific command any time any user connects via SSH, even if just for tunneling. Is this possible? I've ...
1
vote
0answers
60 views

Why can't SSH use my public key?

I'm trying to figure out why I can't get SSH public key authentication working with my school's UNIX server. I obviously don't have root access, but I've attached verbose SSH output and permissions of ...
0
votes
1answer
22 views

ssh, hashed known_hosts: extract plain text and use wildcards

In ssh clients, file .ssh/knwon_hosts may use plain text (this happens, for example, in FreeBSD 12.0): <ip_address> ecdsa-sha2-nistp256 ...
1
vote
1answer
21 views

Several representations for key fingerprint

In ssh server and client authentication, key fingerprints are presented in different ways, even using the same command ssh-keygen -lf (in different hosts or as regards different keys). Representation ...
1
vote
1answer
31 views

ssh, trust hosts on fingerprint basis only, regardless of IP

In ssh configuration directory, the file known_hosts stores for each server the (IP, fingerprint) couple. A server is trusted only if it matches both the elements of one of the couples in known_hosts. ...
5
votes
2answers
62 views

ssh, accept two key fingerprints for the same server IP

ssh clients (by default, at least in Ubuntu 18.04 and FreeBSD 12) always check if server's key fingerprint is in the known_hosts file. I have a host in the LAN which has dual boot; both the OSs use ...
2
votes
1answer
42 views

Passwordless rsync while requiring key and password for all other access

I have a server set up to require public-key authentication for ssh access using a key with a password. Is there a way to set up a password-less key that will only be allowed when executing rsync over ...
1
vote
1answer
38 views

Test if any file was downloaded with SFTP command

How to get the return code of SFTP command? I do this to download all files from a directory. But if the directory is empty the command returns 1 How to fetch the actual code for File not found? ...
0
votes
0answers
7 views

Accessing Jupyter server behind firewall, how to setup the tunneling through VPS?

Settings When I am physically in the office, both the "local" and the "remote" machines are behind the same firewall, and the "remote" machine is accessible by simple ssh command: ssh username@...
0
votes
1answer
26 views

Ubuntu SSH Auth Log Shows Proxy IP

I am trying to figure out an issue I have been having. I am using a webpanel called TinyCP and there is a table for displaying failed login attemps via SSH. All SSH attempts, failed or successful, ...
0
votes
2answers
53 views

error while starting open ssh : /usr/sbin/sshd: /lib/libcrypt.so.1: version `XCRYPT_2.0' not found (required by /usr/sbin/sshd)

I am working on an embedded board, to access that board I need ssh to work smoothly. Currently, for debugging purpose I am using serial connection to access the board. Now, when I try to start ...
1
vote
1answer
50 views

Can I build openssh-portable source code in Alpine linux

For my projects I have to customize the openssh code and I am planning to build the openssh-portable(https://github.com/openssh/openssh-portable) source code in the Alpine linux. But I am getting the ...
0
votes
0answers
37 views

Create Passwordless SSH login without exectuting SSH-KEYGEN on Client?

The normal installation/configuration of SSH on a client requires the use of ssh-keygen to create a local private/public key pair in the .ssh folder of the user's profile. To configure the normal, ...
1
vote
1answer
50 views

Suggestions for SSH Client in Linux Mint

I am using Linux Mint 18.3 on a Dell Laptop. I like the connect to server feature in my file browser windows which allows me to easily access remote directories via SSH. However, as I repeatedly ...
1
vote
2answers
46 views

SSH: Permission denied as given IdentityFile is not used

I'm using this .ssh/config: Host myserver HostName 12.34.67.89 User anyuser IdentityFile /root/.ssh/anything_rsa But running ssh myserver returns a Permission denied (publickey) error. ...
0
votes
1answer
37 views

Can't get SSH daemon running on macOS

The server is running macOS Mojave 10.14.4. I'm unable to get the SSH daemon to start. After logging in locally, I run: $ launchctl list | grep ssh - 0 com.openssh.ssh-agent $ ps -A | grep ssh ...
2
votes
2answers
185 views

Why I can use only private key to login a server using ssh?

I generated the keypair in Computer 1. And move the public key to the Computer2(server) and make it in authorized_keys. And move the private key to Computer3(client) and use ssh-add to add it. ...
0
votes
2answers
52 views

ssh ControlPath use ip address instead of hostame %h

Presently I am using this for controlpath ControlPath /home/user/.ssh/sockets/ssh_mux_%h_%p_%r If i connect to a hostname 'redishost' it creates socket with redishost If i connect to same host '...
0
votes
0answers
23 views

ssh tunneling closed by remote host

as from the beautiful answer in this, I am trying to make a ssh tunneling from my desktop to a cluster. My .ssh/config looks like: Host gateway User rudrab Hostname <ip of the ...
0
votes
1answer
46 views

Openssh Questions

I was reading about OpenSSH and I have the following questions: What is the difference between ssh and slogin? What is the difference between scp and sftp? Does sshd (on server side) provide separate ...
1
vote
0answers
112 views

sshd_config Match rule to catch target Host

I have a jumpbox server for SSH with an external IP that has DNS match with a wildcard - i.e any address with this structure: *.mydomain.com will result with the same IP which is the jumpbox IP. what ...
0
votes
0answers
103 views

Script not executing with ssh and sshpass

I have a script in my .gitlab-ci.yml which is not being executed. Here's the script: - apk update - apk add --no-cache openssh-client sshpass - sshpass -p "${USER_PASS}" ssh -o ...
1
vote
1answer
36 views

OPNsense 19.1 removes root's authorized_keys when reboot / shutdown+turn on

I have an OPNsense 19.1 virtual firewall, which is based on FreeBSD 11.2 HBSD (HardenedBSD). I added it to Ansible Server inventory (with the right configurations), and once copied the PK to that BSD ...
2
votes
1answer
34 views

OpenSSH: if the server is set to “PasswordAuthentication no” then is there any risk if the *client* is set to “PasswordAuthentication yes”?

For all my servers PasswordAuthentication is set to no in the sshd_config file. This means that only key authentication is allowed. In this situation, is there any risk if PasswordAuthentication is ...
0
votes
0answers
20 views

ssh-keygen print certificate file in older versions

The version I am using seem to be old and doesn't have the -L option. -L Prints the contents of one or more certificates. Is there an alternative way to do it? The script I'm using basically use ...
0
votes
1answer
46 views

Simply adding to SSH known_host without forcing an error?

I have two machines devbox, and gitbox. The second machine, gitbox is a development box that has no shell, and is very locked down just to afford git over ssh (there isn't access to /bin/true even) ...
1
vote
1answer
57 views

Is this SSHD config appropriate / secure [closed]

On the latest Debian Stretch I installed an OpenSSH server which I set up under the following conditions. no root login no password authentication / force public key authentication authentication by ...
0
votes
0answers
28 views

SSH breaking my terminal on unsuccessful command [duplicate]

In a an Scala application running on a remote computer, I've added a call I can make that opens a reverse tunnel to a port on a server with a public IP I can connect to afterwards. The tunneling ...
0
votes
0answers
31 views

SSH - root login disabled, password disabled. Still need a complex root password for local sessions?

If this computer's openssh server requires keys for SSH logins, do I still need to have a complex password? Given that this is a private single-user computer in a secure building.
0
votes
0answers
63 views

OpenSSL Missing Ciphers

I have two instances of RHEL (6.2 and 6.5) both using the same versions of OpenSSL and OpenSSH (albeit different versions). Red Hat Enterprise Linux Server release 6.2 # yum info openssl Installed ...
0
votes
0answers
80 views

Ubuntu 16.04 - Cannot SSH with root user, login successfully but closed immediately with return code 254?

I could SSH to 1 server with a non-root user. However, I tried to enable root login at /etc/ssh/sshd_config with this content: # Package generated configuration file # See the sshd_config(5) manpage ...
0
votes
2answers
119 views

WSL: Keeping ssh private key accessible as long as I don't restart Windows 10 (like the behaviour of pageant)

So far on Windows 10 I used mainly the PuTTy bundle (PuTTygen, Pageant and PuTTy, etc) to SSH into remote Linux machines. I use Pageant as a private key holder to hold to private key (and possible ...
0
votes
1answer
36 views

Getting “Enter passphrase for key” for a linux machine from shell script [duplicate]

Context: Want to automate a process which requires a connection to Linux vm machine from code running on AWS cloud. Code Snippet: #!/bin/sh ssh -i LinuxVM.ppk testuser@<ipadress> 'df -h'. ...
0
votes
1answer
40 views

what exactly do I need to make my pc an ssh server and connect to it? [closed]

I tried to create ssh server on my pc. It connects well on LAN but over internet it does not. I have tried everything that I can. I can connect to azure server from pc though. I am running arch ...
1
vote
1answer
72 views

(root) Warning: Identity file /dev/fd/62 not accessible: No such file or directory

Very similar to Failed to open config file '/dev/fd/63', error: No such file or directory for wpa_supplicant except for the fact that I am running as root. bash-4.4# autossh -v -M 0 -4 -o ...
4
votes
1answer
225 views

Forward abstract unix socket over SSH?

I've discovered that OpenSSH is capable of forwarding UNIX sockets like this: ssh -R /var/run/program.sock:/var/run/program.sock My question is whether this extends to abstract unix sockets too. I'...
1
vote
0answers
317 views

Reverse SSH-Tunnel with Socket

I would like to establish a reverse SSH-tunnel (with OpenSSH_7.4 or newer). The purpose is to allow SSH-connections from a central server to multiple devices whose task it is (among others) to ...
0
votes
0answers
52 views

Filezilla EOF SFTP Error

A router is accessible with Putty via SSH. A remote user was a to login from the command-line and scp a file. Attempts to login with Filezilla are met with errors: Error: Received unexpected end-...
0
votes
1answer
136 views

Using OpenSSH to create overlay IPv6 network [closed]

If there's a SSH setup like this: Host A -> Host B <- Host C Where Host C is behind a NAT/firewall an opens a reverse tunnel to Host B and Host A connects to Host C via Host B (ProxyCommand). ...
1
vote
0answers
400 views

SSH ClientAliveCountMax & ClientAliveInterval not working

I changed the following SSH config (and rebooted the SSH, or even rebooted the server): ClientAliveCountMax 120 ClientAliveInterval 720 LoginGraceTime 300 Problem is that the parameter "...
0
votes
0answers
52 views

Why do I keep my SSH connection, after suspending, if I have a window open on the server?

I've noticed this strange behaviour. Everytime when I'm connected to a remote machine, using SSH, and want to go away from my machine (for lunch, for example), I suspend it. And when I type in the ...
0
votes
0answers
33 views

SSH terminal messes multiline commands [duplicate]

I am frequently using ssh terminal. If I enter a command that spans multiple lines, the characters which do not fit onto the first line are going to the beginning... not of the next but of the current ...
0
votes
1answer
145 views

ssh-keyscan -H returns different keys every time

I'm getting different keys every time I run ssh-keyscan -H some.hostname.example. Why is that? Is the server continuously changing keys? They keys I'm getting from one run seems to work even after a ...
1
vote
0answers
31 views

alternative to sshd first-match-only MATCH configuration

Given an openssh (1:7.2p2-4ubuntu2.6 on ubuntu 16.04) installation, I find myself with multiple tiers of groups that I'd like to work with. The way I'm trying to set up the groups is effectively this: ...
2
votes
1answer
431 views

What encoding is used for the keys when using `ssh-keygen -t rsa`?

When I run: ssh-keygen -t rsa to generate a public/private key pair in files e.g. id_rsa.pub and id_rsa, my understanding is that the public key encodes a prime number p, and the private key encodes ...