Questions about the OpenSSH implementation of the ssh protocol.

learn more… | top users | synonyms

2
votes
1answer
940 views

Are dropbear and OpenSSH host keys compatible?

The title basically says it all. But mind: host key, not the login key. And if they're not compatible out of the box, is there a way to convert between them - and what would be the steps in that ...
0
votes
0answers
70 views

Proxy from OSX laptop to debian server for web browsing

I want to setup a proxy from my OSX laptop (10.9) to a debian server via SSH, to browse the net via that server. The debian server has an openssh-server running, and I can login. I tried several ...
2
votes
1answer
207 views

Is there a way to run a privileged command upon successful SSH login (not necessarily with shell or PTY)?

I'd like to run a privileged command upon successful SSH logins at the server's end. However, this has to be in the server configuration (sshd_config or anything else that cannot be manipulated or ...
3
votes
2answers
3k views

check if latest openssh patch provided by RHEL is installed

We have encountered a security threat in one of our RHEL servers which says the SSH server is configured to use Cipher Block Chaining. As far as I know, the RHEL systems provide security updates ...
7
votes
2answers
394 views

Determine dynamically allocated port for OpenSSH RemoteForward

Question (TL;DR) When assigning ports dynamically for remote forwarding (a.k.a. -R option), how can a script on the remote machine (for instance sourced from .bashrc) determine which ports were ...
3
votes
1answer
1k views

Generate own (stronger) RSA host key for OpenSSH?

I would like to replace the default 2048 bit host key generated when installing OpenSSH or starting it the first time with one of 4096 bit length. This leads to two questions: Does OpenSSH allow ...
0
votes
3answers
3k views

How I Determine The latest OpenSSL patch is installed?

This post is about applying the latest patch for OpenSSL to protect our port 443 web traffic, not using ssh to log into these systems. I went and obtained the lastest OpenSSL tarball source patch ...
1
vote
2answers
143 views

using ssh-agent

I have my desktop in the office. When X starts, ssh-agent starts automatically. I have to add my SSH key once, at the beginning, and then I can use ssh without having to enter my password each time. ...
6
votes
3answers
1k views

How to prevent “Last Login:” message from showing up when using sftp?

In Ubuntu GNU/Linux 12.04, I have a user johndoe that is part of an sftponly group, set up to sftp to a chroot jail using Subsystem sftp internal-sftp Match Group sftponly ChrootDirectory %h ...
2
votes
0answers
1k views

Force ssh to always use SSH_ASKPASS

I want to force ssh to always use the program specified by SSH_ASKPASS. In my case the program is just a bash script returning the passphrase. The problem is, as the ssh documentation says: If ...
1
vote
0answers
275 views

SSH to Windows 7 with cygwin openSSH freezes when remote conection [closed]

When I SSH into Windows 7(Cygwin) from a remote, the session freezes after few seconds or up to two minutes. This can happen while I'm typing and it can happen when idle. This is still happening after ...
4
votes
1answer
86 views

Accept any private key for authentication

Is it possible to configure OpenSSH (or any other standard sshd) to accept any key offered by a connecting client? EG ssh -i ~/arbitraryKey hostname grants a login shell while ssh hostanme doesn't. ...
1
vote
1answer
910 views

Understand debug messages from sshd [closed]

I'm using OpenSSH_5.8p1 in my machine,I'm connecting my machine using putty client but its slower so I have ran sshd in debug mode and found following messages can any one explain me in detail about ...
3
votes
2answers
181 views

Denying “/opt/” access for SFTP Users other than particular dir

This is my first (newbie) post here in unix stackexchange. I want to use my WebServer (Debian) as SFTPServer giving access to particular employees. The dir structure is as follows under root: ...
0
votes
0answers
125 views

sshd without pam slower

I am running OpenSSH_6.5 with UsePAM yes in my board. I have observed that with UsePAM no in /etc/ssh/sshd_config, sshd runs slower than previous case. How is this possible? My understanding is ...
1
vote
1answer
290 views

ssh connection fails after login at one user

Have server with 2 users - (e.g. - user and root). SSH login to root works corrctly. But I can't login to user - it immediatelly fails with "write failed - broken pipe" after login. ssh -vvv ...
1
vote
1answer
2k views

How can I have a SSH banner appear BEFORE the “login as:” prompt? [duplicate]

CentOS 5.x When I enable the Banner /path/to/banner parameter in my sshd config file, the banner displays AFTER the login as: prompt. For example: login as: foo ...
7
votes
1answer
9k views

Single command to login to SSH and run program?

Is there a way to structure a single command to login via SSH to a remote server and run a program on the remote login shell? In the OpenSSH manual, it reads "If command is specified, it is executed ...
1
vote
0answers
173 views

git push in gnome-term crashes my window manager

In terminal in awesome wm when i git push awesome wm freezes. so i move over to tty2 and log in. top shows awesome at %100 cpu. ps aux | grep [g]it output git-remote-https origin ...
0
votes
1answer
372 views

SSH to Linux Container from Other Machine

I am trying to learn about Linux Containers and this is my first encounter with servers, ssh and many other things that I do not know the terms yet. I create five different containers and authorized ...
0
votes
1answer
757 views

Double port forwarding - SSH

NOTE: I'm not explaining why I want to do this. But here is the requirement. There are 4 hosts. Host A, Host B, Host C, Host D Host A is running some application which can be accessed at port 8001 ...
5
votes
2answers
200 views

Why are rules not combining in an ssh config file?

It seems like the following would work as expected, i.e., that the second rule, having a hostname that matches the first rule, would apply it. Host *.hostname.com User myuser IdentityFile ...
1
vote
1answer
547 views

Setting the bash SHELL for remote openSSH connections?

I am connected to a Freebsd 10 -STABLE server with SSH from my office box but when I trying to work inside the session I encounter these problems: although I did chsh for every user in said server ...
0
votes
1answer
122 views

Linux Fedora Core 18 freezes on OpenSSH login

miagos:~ $ uname -a Linux miagos 3.9.6-200.fc18.x86_64 #1 SMP Thu Jun 13 18:56:55 UTC 2013 x86_64 x86_64 x86_64 GNU/Linux I have a reproducible issue, when my desktop Linux node stays online for more ...
4
votes
3answers
24k views

Where are my sshd logs?

I can't find my sshd logs in the standard places. What I've tried: Not in /var/log/auth.log Not in /var/log/secure Did a system search for 'auth.log' and found nothing I've set /etc/ssh/sshd_config ...
4
votes
2answers
238 views

SSH - How to make X applications run on client?

I have the reverse problem that most people seem to be having. If I start an X application while logged into ssh, it displays on the server(host) machine instead of the client(local). This is the ...
0
votes
1answer
79 views

Supply additional ssh options in config file

How can I supply additional options in .ssh/config? I know that information like Host, Port, User etc. may be used in the ssh-configuration file to abbreviate ssh commands. I frequently create ...
0
votes
0answers
2k views

OpenSSH hangs after login without showing login prompt

I ran across an issue with ssh after fresh Ubuntu 13.10 installation on Lenovo T420. I tried git pull (which failed) and this led me to more general ssh failing. After spending some 2-3 hrs of ...
1
vote
1answer
1k views

ssh_exchange_identification: Connection closed by remote host on vnx machine (linux)

I changed the password of my linux machine . I was able to login for sometime and after that I am not able to ssh. I am getting the following error: ssh es4042cs -v OpenSSH_5.1p1, OpenSSL ...
3
votes
1answer
595 views

Disable ForwardX11Timeout without ForwardX11Trusted in OpenSSH Client?

By default, recent versions of OpenSSH automatically set ForwardX11Timeout to 20 minutes if you set ForwardX11Trusted to no. This means that 20 minutes after you start your ssh connection, you can't ...
3
votes
2answers
1k views

SSH access from inside and outside a LAN using the same terminal command

I have a Raspberry Pi (RPi) and I am making remote connections to it using ssh. I have managed to set up ssh correctly such that I can access the RPi both from a local area network and from the ...
0
votes
0answers
316 views

How can I get ssh working on Mint Olivia?

I have a Mint KDE VM (under VMware Fusion on Mavericks), and it is refusing ssh connections. I have not enabled UFW, and openssh-server installed without reported error. However, when I attempt to ...
2
votes
3answers
2k views

Trying to SSH into my Android phone, but connection closed

I am trying to use the ssh/sftp Daemon app on Android, and SSHing into the phone using an openssh client. Here is the verbose output I get right before the connection breaks debug1: Authentication ...
1
vote
1answer
361 views

Session limit for OpenSSH server on Ubuntu Desktop 7.10

I need restrict session limit on my OpenSSH server only for one session (one connection). I use Ubuntu Desktop 7.10. Of course Version is old, but I need it for experimental purposes. I tried modify ...
1
vote
3answers
304 views

Can't ssh to a machine

All of a sudden, I couldn't ssh to a machine to which I used to ssh earlier. Consider I am ssh-ing from A to B. Output when I run ssh root@ip_addr_of_B I get: Permission denied ...
5
votes
1answer
2k views

sFTP server fails to start

I'm having problems getting sFTP working while there are no problems with ssh. I'm basically building zlib, openssl, and openssh for an ARM processor using an existing embedded Linux filesystem. After ...
6
votes
2answers
1k views

Why not simply use %h in OpenSSH ssh's ControlPath option?

Why do the "ssh_config(5)" manpages recommend that the ControlPath option should contain at least the %h, %p and %r placeholders in order to uniquely identify each shared connection? I thought that ...
8
votes
2answers
12k views

What do the channel numbers in ssh error message refer to?

In the example below what do the channel numbers correspond to? Which are on the server? Which are on the client? $ ssh -L1570:127.0.0.1:8899 root@thehost Password: Last login: Fri Aug 9 ...
13
votes
1answer
9k views

Convert OpenSSH private key into SSH2 private key

Is there a way to convert existing pair of OpenSSH keys to the SSH2 (ssh.com format) pair of keys? UPD: since there are some answers about ssh-keygen suddenly appeared, I'll explain where I came ...
3
votes
2answers
475 views

how does ssh discover hostnames on the network?

We have a server on the company network named serverA, and if I type ssh serverA, it will connect my PC to this server, even though there is no entry for this server in my /etc/hosts, but I used to ...
2
votes
2answers
332 views

Unable to force passphraseless ssh authentication while port forwarding

I'm completely at a loss as to what is preventing my local machine from authenticating the connection that is being forwarded from the remote server. I've read a ton of the posts on here regarding ...
3
votes
1answer
86 views

What are all of the SSH Key files?

There are six key files in /etc/ssh directory for private and public keys. 4 of them are for DSA and RSA public & private keys. but there are two more files named ssh_host_key and ...
1
vote
1answer
208 views

How to prevent ssh-agent from starting in CentOS?

How do I stop ssh-agent from starting when logging into CentOS via openssh? There are no references to ssh-agent in my bash startup scripts (.bashrc) or /etc/bashrc.
3
votes
2answers
318 views

Why doesn't the ssh command follow RFC on URI?

The RFC: Uniform Resource Identifier (URI) Scheme for Secure File Transfer Protocol (SFTP) and Secure Shell (SSH) presents the SSH URI as: ssh://[<user>[;fingerprint=<host-key ...
5
votes
1answer
118 views

Can an OpenSSH server forward inbound traffic to another server?

In my current work setup, I have: Windows 7 laptop Ubuntu virtual host / SSH Windows 2k8 guest I'd like to be able to RDP from my laptop into the Windows guest without having to open additional ...
15
votes
3answers
12k views

What difference between openssh key and putty key?

I've found ssh-keygen ("ssh" package) comand produce another keys that puttygen command ("putty" package). If I create public and private keys with ssh-keygen some ssh-servers can not accept my keys. ...
2
votes
1answer
948 views

ssh-add -D doesn't erase stored keys from the ssh-agent

How come this happens?: stan@tcpc:~/.ssh$ ssh-add -l 8192 e0:45:5e:cc:45:3e:17:2b:a6:54:6f:8d:53:1b:j2:e3 github (RSA) 2048 25:41:53:a6:45:5d:ac:eb:5c:45:f8:ce:42:a9:he:aa BITBUCKET (RSA) ...
12
votes
5answers
780 views

what's the purpose of ssh-agent?

I've read the official definition: ssh-agent is a program to hold private keys used for public key authentication (RSA, DSA, ECDSA). The idea is that ssh-agent is started in the beginning of an ...
0
votes
1answer
81 views

ssh private key stops accepting my passphrase

When booting my laptop today I found that ssh (openssh) simply refuses to accept my passphrase when reading my private key. My only idea of how that could've happened is if the HDD has somehow ...
2
votes
1answer
105 views

Assuming sshd allows only public key authentication, how do I log the fingerprints?

With OpenSSH, how can I log the fingerprints of the keys used for authentication? I would like to log it in production, so it would be best if this wasn't just some debug setting or similar.