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Questions tagged [openssh]

Questions about the OpenSSH implementation of the ssh protocol.

0
votes
1answer
17 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
votes
0answers
29 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
54 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
56 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 ...
0
votes
0answers
32 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 ...
-1
votes
0answers
40 views

X11 forwarding from Linux Red Hat to Windows 10 running OpenSSH

I've installed OpenSSH on my Windows 10 machine and can now run ssh -X root@123.456.789.0 and log in. That works fine. I can even use vim to edit files on my Red Hat server, including /etc/ssh/...
0
votes
0answers
46 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
39 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 ...
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0answers
23 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 ...
2
votes
1answer
330 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
votes
0answers
60 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
75 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 ...
2
votes
1answer
77 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
59 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
36 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 ...
0
votes
0answers
70 views

ssh-keygen cannot convert private key to different format

I have a OpenSSH private key in the following format: -----BEGIN OPENSSH PRIVATE KEY----- ... -----END OPENSSH PRIVATE KEY----- I want to convert this file to a ssh2 format, and I do the following: ...
2
votes
1answer
28 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
115 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
40 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
35 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
133 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
29 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 ...
0
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0answers
124 views

SSH timeout on simple connection

Yesterday i made a new installation of Ubuntu 18.04. Problem I'm trying to connect to my Digital Ocean vps like always with the ssh user@ip command but it gets stuck on ssh: connect to host ...
0
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0answers
54 views

Linux server is not accept ssh private key to login without password?

I'm trying to connect to a server (as user) with a RSA key. I have uploaded the key using ssh-copy-id and it is properly located in ~/.ssh/ folder. Typically this would be enough to connect to the ...
0
votes
0answers
54 views

cannot move imported SSH key to yubikey

I am using my RSA key to access some servers via SSH, and I would like to move it to my new yubikey and keep using it. I had successfully imported the key into gpg following the advices from THIS post,...
2
votes
1answer
71 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
144 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 ...
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votes
0answers
70 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
30 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
515 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
25 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
22 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
128 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
47 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
200 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
35 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
31 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
51 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
202 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
1answer
178 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 ...
6
votes
1answer
9k 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-...
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votes
0answers
18 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....
1
vote
1answer
99 views

OpenSSH's SSH client not respecting order of IdentityFile settings

How can I specify the order in which OpenSSH's SSH client (OpenSSH_7.5p1, OpenSSL 1.0.2k 26 Jan 2017; Git for Windows v2.11.1) offers the public/private key pairs to a SSH compliant daemon such as ...
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votes
0answers
130 views

Solaris 11.3 and SSHD privilege separation

I'm working on a OpenSSH server installation on Solaris 11.3. When I build OpenSSH 7.7p1 from source and install it make dies at the end after installing the components: $ sudo gmake install ... /...
1
vote
1answer
385 views

How to store RSA-4096 SSH key in OpenSSH's new key format

I seem to be not able to generate a RSA-4096 SSH key in OpenSSH's new key format with the following command: $ ssh-keygen \ -f rsa4096_key \ -t rsa \ -b 4096 \ -C 'This is a test' \ -o \ -...
1
vote
3answers
550 views

Running `scp` client -> server results in scp command not found (on server), why?

We've intentionally built OpenSSH using this switch: --with-default-path blank. We're attempting to deploy OpenSSH so that the server does not include the scp binary. Now when we try to do an scp ...
6
votes
4answers
2k views

If a CVE database lists my version of OpenSSH as vulnerable, is it possible that it has been patched but retains the version number?

I am using OpenSSH version 7.4p1, in CVE database I found that cpe:/a:openbsd:openssh:7.4:p1 is vulnerable to CVE-2017-15906 https://www.cvedetails.com/cve/CVE-2017-15906/. Does this mean that for ...
1
vote
1answer
37 views

Opening many tunnels typing the password only once (all accounts in gateways have the same pass)

I want to open many tunnels at once, they all have the same long password. With -f, i.e., ssh -fN -p 22 usr1@gate1 -L 10001:ip1:22 ssh -fN -p 22 usr2@gate2 -L 10002:ip2:22 ... ssh -fN -p 22 usrn@...
0
votes
1answer
823 views

SSH password permission denied

I've just set up OpenSSH on my system (Ubuntu 18.04 LTS), and generated the key using ssh-keygen. When prompted for password, I set it to just one character to test, but when I try to copy the public ...
1
vote
1answer
697 views

Cannot use root ssh despite option “PermitRootLogin yes” in sshd_config

I am unable to connect to ssh despite the fact that PermitRootLogin option is set to "yes" in my sshd_config. ssh localhost root@localhost's password: Permission denied, please try again. Here is ...