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Questions tagged [openssh]

OpenSSH is the most widespread and de-facto standard implementation of SSH protocol. Both server and client tools are included.

OpenSSH is the most widespread and de-facto standard implementation of SSH protocol (Secure Shell). It is the default SSH toolset for most *nix systems. The OpenSSH is open source licensed under BSD license.

The OpenSSH suite includes:

  • sshd - SSH deamon
  • sftp-server - SFTP server subsystem (though in current versions of OpenSSH, the SFTP server is built into the sshd. The sftp-server binary is kept for a backwards compatibility)
  • ssh - SSH terminal client
  • sftp - SFTP client
  • scp - SCP client (internally it works as SCP server too)

Other tools included are ssh-add, ssh-agent, ssh-keysign, ssh-keyscan, ssh-keygen and ssh-keysign.

The OpenSSH server (the sshd) is configured using sshd_config files. The client tools are configured using ssh_config file.

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Is man-in-the-middle attack a security threat during SSH authentication using keys?

I am no expert in network security, so pardon if this question is not very smart :). I am automating logins to some machines using ssh. I am currently avoiding host-key warnings using StrictHostKeyChecking no. I naively understand that someone can…
JP19
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upgrade openSSH 7.2p in ubuntu 14.04

I have a server running Ubuntu 14.04, but I have an issue with PCI requirements. I have installed in my server OpenSSH 6.6p1, then I upgraded it to OpenSSH 7.2p, compiling the code with make and make install directly from repositories from OpenSSH,…
Rigoberto Giraldo Carmona
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Using public key from authorized_keys with Java security

How can I use an entry from the systems authorized_keys file for a java.security.PublicKey implementation? I specifically want to compare a public key from the authorized_keys file with a public key available in the Apache SSHD…
DerMike
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Using only part of a pattern in SSH Config Hostname

I have an SSH config like the one below, which works great for: ssh b21 ssh 23 ssh s267 Example .ssh/config (hostname passed is slotted in at %h): host s* HostName atrcu%h.example.com User example Port 22 host b* HostName…
dueyfinster
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fabric keeps asking for password using SSH connection

I'm trying to connect to a windows azure instance using fabric, but despite I configure ssh conection to execute commands, fabric keeps asking for password. This is my fabric file: def azure1(): env.hosts = ['host.cloudapp.net:60770'] …
kothvandir
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How is the Github handling so many public keys

I'm wondering, how Github is able to handle so many public keys, which are used for authenticating over ssh. One user owns aprox 3 certificates and how many users are on Github - millions? Easy multiplication gives us millions of certificates. It…
Jakub Truneček
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Managing authorized_keys on a large number of hosts

What is the easiest way to manage the authorized_keys file for openssh across a large number of hosts? If I need to add or revoke a new key to an account on 10 hosts say, I must login and add the public key manually, or through a clumsy shell…
Andrew Cholakian
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Error while trying to ssh a docker container : System is booting up

I am trying to build an image and run container as an ssh server. I want to be able to ssh that container (remote_host) from another container (jenkins/jenkins) I am using a VM with Centos. I am using this docker file. I run it from my VM host…
ErEcTuS
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Why can't openssl read an ssh private key created by openssh on OSX

Here is a test script I am using to help debug an issue with openssl &/or ssh on OSX Mojave 10.14.5 with brew installed versions of openssl and openssh > brew info openssh | head -1 stable 8.0p1 (bottled) > brew info openssl | head -1 stable 1.0.2r…
jonseymour
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Are "SOCKS5 proxying" and "ssh tunneling" same thing?

I know that I can run a socks5 proxy by ssh -D some-port-number remote-server-url. I know that I can configure my applications (for example firefox) to use socks5 proxy (often by specifying something like…
Jay Somedon
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How can I programmatically detect ssh authentication types available?

I'd like to write a monitoring plugin that checks various hosts on my network to make sure that password or interactive SSH authentication is not enabled. That is, I need to write code that: Connects to an SSH port. Enumerates available…
Stef
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What's openssh default kexalgorithms?

If KexAlgorithms is not configured explicitly in an ssh config file, what's the default key exchange algorithm openssh may use? The openssh version I am using is OpenSSH_6.4p1.
user1097213
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OpenSSL headers missing when building OpenSSH

I want to build a certain OpenSSH version with a specific OpenSSL version from sources, but I get the following error: mkdir /tmp/ssh cp openssh-6.7p1.tar.gz /tmp/ssh cp openssl-1.0.1l.tar.gz /tmp/ssh cd /tmp/ssh tar zxvf openssl-1.0.1l.tar.gz cd…
name
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Has KeyRegenerationInterval any effect in SSH2?

I am setting up a new Linux-Server and I am editing sshd_config. I will use protocol version 2 (which is default anyway): Protocol 2 But in the default config-file I also find this two lines: KeyRegenerationInterval 3600 ServerKeyBits 768 Manpage…
Hubert Schölnast
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kex_exchange_identification: Connection closed by remote host

I've wanted to connect my share hosting with ssh. So I generate an ssh key in the ssh action of cpanel and authorized it. Then I've downloaded the private key and drop it in the ./ssh folder of my MacBook.I've used this code to connect my host. ssh…
Hanie Asemi
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