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Questions tagged [openssh]

Questions about the OpenSSH implementation of the ssh protocol.

0
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1answer
38 views

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

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
21 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
56 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
40 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
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0answers
13 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
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1answer
36 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
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0answers
50 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
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0answers
33 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
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0answers
28 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
44 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
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0answers
20 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
136 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 ...
0
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1answer
68 views

use chroot to lock down sftp access without root owning folder

Everything I am reading says that for chroot to work with sftp root has to own the folder. I want to make it so a user can only sftp to a sub-directory in their home folder like /home/user/some/folder....
0
votes
1answer
26 views

iptables, vpn server, routing

I set up my server (let's call it server A) firewall so that no input/output rules be allowed, apart from: - incoming ssh conection - outgoing ssh connection This is working well by now! Now, i ...
0
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0answers
40 views

Require a yubikey AND (publickey OR password) for SSHD auth

I am attempting to configure OpenSSH on a Debian based system to always require a yubikey TOTP AND either a publickey OR password. I realise other combinations are possible through ...
-2
votes
1answer
274 views

install openssh 7.6 on red hat 7.5 [duplicate]

I have a redhat server 7.5. I have a openssh installed on this server. The openssh is 7.4. I need to upgrade openssh 7.4 to 7.6 AS Nessus, vulnerability scanner scanned this vulnerability (Openssh <...
0
votes
1answer
467 views

Upgrade OpenSSH 7.4 to later on RHEL

I have a Red Hat Enterprise Linux server (7.5 x86_64). I have OpenSSH version 7.4. I was asked to upgrade it to a later version for security reasons: Nessus states that OpenSSH should be ugraded from ...
1
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1answer
103 views

Update OpenSSH on RHEL 5.5

I must update OpenSSH on my RHEL 5.5 because of CVE-2018-15473. My OpenSSH version is OpenSSH_4.3p2 and must be update to OpenSSH_7.9, when i want to do this i get that message when using configure ...
0
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0answers
52 views

SSH connection failure: processing of forwarded request fails on known_host key

When I attempt a SSH connection between client C and server S (both on the same LAN) the client looks up the server's key in the client user's known_hosts file. In the usual case for connection ...
0
votes
2answers
53 views

What are the various levels in ssh -vvv: debug1, debug2, debug3

Is each a different side of the connection or a deeper layer of logging. I am interested because of, for example, this excerpt from a vvv output debug3: send packet: type 30 debug1: expecting ...
1
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0answers
62 views

How could I debug sshd taking several minutes to start?

I use a VM with ssh and X forwarding to run certain applications. When launching the VirtualBox VM, it takes several minutes for ssh to come online, even though the machine is at the desktop ...
3
votes
1answer
888 views

OpenSSH Server won't start on orangepi/linux

I am currently doing some testing with an Orange Pi. After doing an update on a fresh install it seems as though the ssh server is no longer able to start itself, and I'm not able to manually start it ...
0
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0answers
79 views

SSH forwarded through modem recently started failing: update

Server host Ubuntu 18.04: Openssh-server/bionic-updates,bionic-security,now 1:7.6p1-4ubuntu0.1 amd64 Modem: Arris Xb6 Tested with clients: Ubuntu 18.10: openssh-client/cosmic,now 1:7.7p1-4 amd64 ...
1
vote
1answer
180 views

How do I connect to an SSH server with no ciphers in common? [duplicate]

I'm running Kali Linux with ssh -V of OpenSSH_7.7p1 Debian-3, OpenSSL 1.0.2o 27 Mar 2018. I tried to SSH to a server (a hacking challenge) and got the response Unable to negotiate with ********* port ...
3
votes
1answer
241 views

SSH only after login?

I've freshly setup a rather standard current Arch Linux and encounter a problem that I can not get a grip on: DHCP service is enabled and network is online (ping succeeds with hostname and IP ...
-2
votes
1answer
107 views

Troubleshooting ssh connection with RSA key [closed]

Here is what I see in the logs debug1: SSH2_MSG_SERVICE_ACCEPT received debug1: Authentications that can continue: publickey,gssapi-keyex,gssapi-with-mic,password debug1: Next authentication method: ...
1
vote
0answers
49 views

Remove inactive SSH process (on server) after connection dropped (on client)

I'm using the following command on a client for port tunneling: autossh -M 20000 -4 -N -f -R 18822:localhost:22 <user>@<vps-ip> Sometimes the client would lose connection or power for a ...
2
votes
1answer
57 views

What does `ssh-keygen -r` do if a public key is not specified?

Short Question I'm assuming that ssh-keygen -r hostname uses a default public key. I would have thought that it would default to ~/.ssh/id_rsa.pub, but that does not appear to be the case. So what is ...
0
votes
2answers
427 views

SSH Remote port forwarding with multiple ports

For those who worked with ssh port forwarding or for those who have an idea, I managed to create a remote tunnel from my PC to a remote machine(a camera that does not have a public address) through a ...
0
votes
1answer
57 views

ssh to docker container breaks after 45 seconds

I have docker running on a synology nas. The nas has a private network (172.17.0.0/16) where docker places the containers. It also has a public facing interface on my lan, call it 10.11.12.10/24. ...
0
votes
1answer
58 views

Changing hostname more than once via ~/.ssh/config

I have the following set up in my ~/.ssh/config match host devbox compression yes user hari port 22 hostname 192.168.9.7 match originalhost devbox exec "~/.ssh/check_if_outside_home.sh" ...
1
vote
1answer
614 views

ssh to Cisco device not working [duplicate]

I have an issue where my server is not able to ssh to a cisco device after upgrading the server to the latest version. I did a ssh -vvv, I am not sure about two sections. Below are the details : I ...
-2
votes
1answer
31 views

ssh to a linux box going through 2 servers

I would like to ask for your ideas, we have a somewhat complicated network setup and I need to connect to dozens of linux boxes and sometimes need to do remote reboot on them but before I can even ...
2
votes
1answer
110 views

How to enable up-arrow command history and command completion in sftp on Gentoo?

When I try to use up-arrow command history via sftp to my CentOS 7 server it just prints ASCII characters to the output instead of recalling recent commands: sftp> ^[[A It's very time consuming ...
0
votes
1answer
258 views

show values of an ed22519 private key stored in OpenSSH format

(note this question uses both 'openssh' and 'openssl' in the text, I am not confusing the two.) If I use openssh to general an RSA keypair (ssh-keygen) then I can use 'openssl rsa -in ...' to view ...
0
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0answers
90 views

Can`t connect through ssh using passwordless technique to centos 7 as user but as root succeeds

I have been trying log in to my centos 7 using the passless technique. First I have generated a public key: ssh-keygen then tried to connect keys with remote: ➜ ~ ssh-copy-id user@xxx.com /usr/...
1
vote
1answer
62 views

ssh using OpenLDAP (LDAP) credencials

I have a corporate network with an OpenLDAP installed and functional. I can log in a Linux server in this network using ssh with my profile (user) that is in OpenLDAP. I created a new user with ...
0
votes
1answer
1k views

SSH port forwarding: “Privileged ports can only be forwarded by root” error

I wanted to forward my local 8080 port to the 80 port of the server I want to log in via SSH, so I did: ssh -L 80:127.0.0.1:8080 -N -f myserver But I get the error: Privileged ports can only be ...
0
votes
1answer
28 views

zsh script testing ssh successfully or not

I have a zsh script script.zsh server-name-here that have one argument, I need to test ssh to that server-name-here, and if success continue doing something, if not exit script. How can we achieve ...
0
votes
1answer
25 views

OpenSSH prompts for password for `~/.ssh/id_rsa` which is already in ssh-agent

When I attempt to SSH to a host, ssh still prompts for the password of the ~/.ssh/id_rsa key (Which was generated and exported from PuTTYgen), even though the password is already loaded in ssh-agent (...
-1
votes
1answer
178 views

Probe SSH connection and detect ssh disconnect or logout

I'am running a script to connect to another host (via ssh) and it's doing some deployment work. I need to detect the ssh connection is closed/or interrupted, then need to execute a command to delete ...
1
vote
3answers
48 views

How to make a restricted user which can only start a shellscript?

How can I create a local user, which can log in via SSH to linux machines, ex.: SLES12 and can only execute a shellscript, which comes up after SSH login? So it shouldn't be able to trick that it ...
1
vote
1answer
343 views

How to log all SSH activity on server with user's hostname or User name?

I have an Ubuntu server and I want to log all SSH activity on my server. For this, I found one good document here (https://askubuntu.com/questions/93566/how-to-log-all-bash-commands-by-all-users-on-...
1
vote
2answers
45 views

Does OpenSSH >=7.2 support local-side tilde expansion for remote Unix socket forwarding

I am trying to forward a gpg-agent Unix socket to a remote machine. I have tried the following two versions of the remote forwarding command: A: ssh -vvv -N -R ~/.gnupg/S.gpg-agent:~/.gnupg/S.gpg-...
2
votes
2answers
37 views

ssh-copy-id returns error “rootsh: bad characters in arguments”

I'm trying to use ssh-copy-id in order to copy my id_rsa.pub into ~/.ssh/authorized_keys in remote host. I execute the following: $ ssh-copy-id remoteuser@remotehost But I have the following error: ...
1
vote
1answer
75 views

Disabling openssh client AAAA DNS queries

I have a Stretch-based desktop with IPv6 disabled, both as parameter in the kernel. I have the ssh client from the openssh-client package, version 1:7.6p1-2.0nosystemd1, installed. Upon debugging a ...
0
votes
1answer
260 views

ssh with new user failing with Permission denied (publickey)

I am trying to create user on EC2, following are the steps I performed. root$ adduser abc --disabled-password root$ sudo su abc abc$ mkdir /home/abc/.ssh abc$ chmod 700 /home/abc/.ssh abc$ touch /...
4
votes
2answers
276 views

How to exit OpenSSH control master process without using lsof or fuser?

Is there a more direct way to exit an OpenSSH control master process and delete its socket file than with the help of the programs lsof or fuser and without knowing the destination host (connection ...
8
votes
1answer
16k views

ssh Unable to negotiate: “no matching cipher found”, is rejecting cbc

I am trying to ssh to remote machine, the attempt fails: $ ssh -vvv admin@192.168.100.14 OpenSSH_7.7p1, OpenSSL 1.0.2o 27 Mar 2018 ..... debug2: ciphers ctos: aes128-cbc,3des-cbc,aes192-cbc,aes256-...
0
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0answers
19 views

ssh-copy-id to port failing [duplicate]

For some reason, I can SSH like this: # ssh first.last@mydomain.dyndns.org -p 2022 But I can't get ssh-copy-id to install key: # ssh-copy-id -i /root/.ssh/id_rsa.pub -p 2022 first.last@mydomain....