Questions tagged [openssh]
Questions about the OpenSSH implementation of the ssh protocol.
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OpenSSH Connection Timed Out Issue
I am using Linux CentOS8 distribution. Openssh 8.0 installed on this server. When I try to connect via SSH to this server, connection timed out happens. I got a tcpdump and tcpdump shows that SSH ...
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Why are 3 entries added to ~/.ssh/known_hosts even though I use only a single key type?
I set up a new server (hostname: odroid) and copied my public ed25519 key to it.
I signed to it for the first time and noticed 3 new entires have been added to ~/.ssh/known_hosts on my local machine:
...
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1
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Why can't I scp a file to this host while I can ssh to it?
I configured sshd on my remote host with /etc/ssh/sshd_config.d/custom.conf:
AddressFamily inet6
PermitRootLogin yes
PubkeyAuthentication no
Match Address fe80::d075:6982:4410:e071
This is a fresh ...
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1
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49
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How to authenticate through OpenSSH then sudo with only one Ticket Service (Kerberos TGS host/fqdn)
By now, we are using OpenSSH GSSAPI authentication on all of our servers (Debian from 10 to 12).
Then we sudo -i, using ldap authentication (through sssd-ldap).
I would like to get rid of the ldap ...
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Setting up a SSH Lab using docker on my local machine
I am using docker ubuntu container to set up an SSH lab on my local machine. I have interactively started the container and installed open ssh on it with other tools. I ensured that I port forward ...
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18
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How do I configure OpenSSH to not use the "-sk" versions of keys for hardware authenticators?
I have a system that needs to connect to several clients through SSH keys. This is in a somewhat legacy environment, and clients have varying OS and SSH versions.
I created a new ed25519 host key on ...
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132
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Log in to remote server by using a generated public key
I have a zsh script with which I logged into a remote host to copy some folders. The system asks me each time to give the password of the local host which I want to bypass, otherwise I have to enter ...
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89
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SSH Keys Not Recognized?
I have two Debian (11 and 12) systems. I'm trying to verify ssh access from server A to server B via keys, following this video https://www.youtube.com/watch?v=vINn1MIrf7o. I try to use the keys, ...
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key type ecdsa-sha2-nistp521 not in PubkeyAcceptedAlgorithms [preauth]
I have trouble setting passwordless authentication on a host:
Sep 21 09:57:36 pvestorage2 sshd[1688625]: userauth_pubkey: key type ecdsa-sha2-nistp521 not in PubkeyAcceptedAlgorithms [preauth]
OS: ...
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What are the OpenSSH ciphers default rekey transmission limit values?
The OpenSSH sshd_config man page says for RekeyLimits first argument:
Specifies the maximum amount of data that may be transmitted before the session key is renegotiated [...]
The default is between ‘...
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Can two linux users share .ssh folder keys to connect to an SSH server
I have two linux users
user1 - regular account with auth key stored in /home/user1/.ssh/
user2 - service account without home directory
How can user2 access user1's keys to connect to the remote ...
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CentOS 7 upgrade openssh to 9.3p2
I am asked for an upgrade OpenSSH version because of CVE-2023-38408, here is my process.:
yum groupinstall -y "Development Tools"
yum install -y zlib-devel openssl-devel wget
cp /etc/ssh/...
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ssh-copy-id closed by remote host
I'm trying to copy public ssh with ssh-copy-id but it gives a connection close:
user@serverA:~/ctm/cm/AFT/data/Keys$ ssh-copy-id -p 1222 -i /home/user/keys/serverA.pub vivek@serverB
/usr/bin/ssh-copy-...
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Are all Debian 11 systems automatically vulnerable to CVE-2023-38408?
I really really hope I'm wrong here, but it seems that Debian 11 has a vulnerable version of OpenSSH.
My OpenSSH banner reports my OpenSSH version is:
8.4p1 Debian 5+deb11u1
I checked with sshd and it ...
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Why does ls show this file twice with different sizes?
Why is 50-redhat.conf listed twice with different file sizes for this directory with this ls:
ls -la /etc/ssh/ssh*
-rw-r--r--. 1 root root 1921 Aug 2 02:58 /etc/ssh/ssh_config
-rw-------. 1 ...
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40
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SSH not working outside of local machine
So, I'm trying to learn SSH. I don't have a public IPv4 address. So, I'm using my IPv6 address but SSH is only working inside my local machine. When I try it with WSL, it is showing
ssh: connect to ...
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36
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Cannot login into SSH from non-admin account. /bin/bash: No such file or directory [duplicate]
Although I have found many other posts on this exact problem, none of their presented solutions have fixed my issue.
I have configured and SFTP and SSH server on my raspberry pi. And ever since I ...
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Incorrect MAC error while using ssh from windows to linux
I am trying to ssh from a windows system to an azure centos vm. But I am getting error incorrect MAC ... On further checking i identified it only happens when the mac algorithm used is umac-128-etm@...
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How can I map the sshd logs to my current ssh session?
I am exploring methods to correlate my current SSH session with the SSHD logs.
I aim to extract specific information from the SSHD logs that pertain to my SSH session only.
Jul 04 09:39:06 linuxbox ...
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Conditionally skip ssh-config options when ssh is too old for them?
How can I use SetEnv in ~/.ssh/config (and the same config on various systems), but not throw an error when ssh is too old to support it?
I've tried adding a Match exec statement to exclude that ...
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154
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What is the difference between a Match all and a Host * block in ssh_config
As I was reviewing my current OpenSSH client configuration file and intensively reading the ssh_config(5) man page, I found that, from my understanding, both Match all and Host * will achieve the same ...
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295
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Does ssh client interfere with named pipes? [duplicate]
Setup:
I have a system in bash where I have a single file that spawns off a pipeline of background processes.
In stage one of the pipeline, there are multiple processes writing to a single named pipe. ...
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1
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147
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Use openssh for ssh connections and for public sftp
I have a system to which some users need to connect trough regular SSH. I will name them the “Privileged Users”.
In the same time this system should provide an SFTP server to “Anonymous” user (without ...
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161
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How to make a script to forward commands to an SSH server?
I have a remote SSH server with several custom utilities for my work. However, there are times when I feel lazy and don't want to start a full SSH session just to execute a single command.
This ...
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0
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326
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Very odd SSH known_hosts verification failure with certificates
I recently upgraded one of my machines to latest Ubuntu 22.04, and now I am experiencing a very strange SSH server verification issue. Here is a short explanation of the situation.
I am using SSH ...
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1
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1k
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How do I convert an OpenSSH-generated ED25519 key to the PEM format?
I am trying to convert an OpenSSH-generated private host key to the PEM format, so that I can use it also in dropbear-initramfs. However, when trying to do so using the ssh-keygen program, I am ...
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Restrict user for ssh tunnelling
I'm trying to create a user without shell access just for port forwarding through ssh. The shell of the user is set to /usr/bin/false, but everytime i try to login through ssh it receive Permission ...
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Setting up a second computer with SSH keys once you've turned off password access
I'm new to managing Linux servers. After some research and study, I was able to generate SSH keys on my laptop and use those keys to successfully log into a new server that I'd just set up. Great. ...
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405
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How to restart sshd after assembly?
it is necessary to update the openssh server to the latest version, since everything is closed, it has come to manually assemble it
./configure --prefix=/usr --with-pam --with-selinux --with-privsep-...
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1k
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Set default permissions for files received via SFTP
I'm receiving files pushed from another system via SFTP to a directory on a Linux VM. These files get the wrong permissions u=rw g= o=. However I need those files to have permissions like u=rw g=rw o=....
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Setting up SSH Password
I've been setting up ssh access to my desktop computer.
I'm running a Debian Distro.
I've enabled password authentication in the sshd_config file, and I've tried looking for the "keyboard-...
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Why does ssh port forwarding fail?
In this example:
$ ssh -L 8001:192.168.122.4:80
the output give is the default help:
usage: ssh [-46AaCfGgKkMNnqsTtVvXxYy] [-B bind_interface]
[-b bind_address] [-c cipher_spec] [-D [...
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ssh port forwarding using config
On a box the command line has been disabled and the ssh prompt is not accessible.
What is the equivalent of:
ssh> -L 8001:192.168.122.4:80
Port forwarding needs to be set up so that a host ...
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539
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SSH freezes or won't even login
On a private network with a machine with private IP address 10.0.0.2 and a machine with 10.0.0.12 I encounter problems with SSH from 10.0.0.2 -> 10.0.0.12.
The machine on 10.0.0.12 regularly ...
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117
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Midnight Commander: shell link connection not show dirs
Everything works fine when the target computer is windows 10 with cygwin and openssh 5.9p1-1 (libopenssl098 0.9.8t-1) [computer1].
After upgrading cygwin with openssh 1.1.1t-1 (libssl1.1 1.1.1t-1) [...
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211
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SSH/Cron services hangs on RHEL 8.6
So, i have an odd issue with my VM RHEL 8.6 test server with Hyper-V.
The problem is the SSH Service hangs from time to time, around midnight.
To connect again to the server i have to Reboot it ...
- 101
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41
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Individual connection of people via ssh
I have different users on the server and each of them has a username and password
I want each user with his own username to be able to connect to the server with only one device at a time and not to ...
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0
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96
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Upgrading OpenSSH when OS version is outdated
I would like to upgrade OpenSSH version (currently version is OpenSSH_4.3p2, using protocol OpenSSL 0.9.8e-fips-rhel5). However, it seems I cannot upgrade it because OS Linux itself has a very old ...
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495
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Meaning of "key options: agent-forwarding" in OpenSSH logging
At first, I'd like to note that I am aware that there are a lot of other questions regarding SSH agent forwarding. The people there wanted to know how to make agent forwarding work or how to configure ...
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Missing libraries after installing openssl (libcrypto.so.1.1, ...)
I made my Arcolinux (5.12.14-arch1-1 x86_64) unusable by trying to install openssh. Googled a few hours and tried something, but without success.
I did the following:
$sudo pacman -S openvpn
Then vpn ...
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1
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509
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how to restrict SSH for specific user from specific subnet
Is there any option to restrict SSH from specific user from specific subnet
for example: [email protected]/24 needs to be disabled.
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PKCS#11 provider in OpenSSH: Is it possible to cache PIN?
I use a RSA key on a smartcard with an OpenSSH client. The smartcard is read by a smartcard reader with a pinpad. The key is protected with a PIN.
Is it possible to cache the PIN somehow? I don't ...
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454
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How to generate ssh key with AES-GCM?
I used that form to create my ssh key : ssh-keygen -t ed25519 -C "[email protected]" and I got: Encryption: aes256-cbc, is it possible to use [email protected] instead?
thanks
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ssh does not use ssh-agent on FreeBSD
I recently set up a new FreeBSD system and am having a lot of trouble getting ssh to use ssh-agent. I have verified with ssh-add -l that my key is added, and the SSH_AGENT_PID and SSH_AUTH_SOCK env ...
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SSH login still ask password even though public key is added in remote machine's ~/.ssh/authorized_keys file
I have a Raspberry pi 4 with a Linux OS & I am using a Macbook. The two machines are in the same LAN.
Raspberry pi IP address is 192.168.10.11. I can ping the Raspberry Pi from my MacBook terminal ...
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365
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ansible copy ssh keys to multiple users' home directory
I have ssh keypair on my ansible_host, which I want to copy to multiple user's authorized keys on target host.
I'm trying with-item construct, but it complaints about .pub key not an invalid key
here'...
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Conditional inclusion in ssh_config
According to ssh_config(5) an Include statement can be placed inside a Match or Host block to create conditionsl inclusion
Include: Include the specified configuration file(s). Multiple pathnames may ...
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3k
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How to read and debug SSH verbose-mode?
Let's say I use this command:
ssh -vvv user@server
I get an output similar to this:
send packet: type 21
ssh_set_newkeys: mode 1
receive packet: type 6
SSH2_MSG_SERVICE_ACCEPT received
receive packet:...
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513
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How to install OpenSSH 8.3 Server on linux?
I am trying to install OpenSSH 8.3 server on linux. I downloaded the file from https://cdn.openbsd.org/pub/OpenBSD/OpenSSH/portable/ and have done all the steps from Install openssh-server 8.0p1 on ...
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How to disable weak HMAC Algorithms? Not found in ssh_config or sshd_config file
A vulnerability scan showed that in a Debian 10 system, insecure MAC algorithms are in use: [email protected],[email protected],[email protected],hmac-sha1
When I do ssh -Q mac, I get ...
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