Questions about the OpenSSH implementation of the ssh protocol.

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1
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0answers
26 views

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

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 ...
2
votes
1answer
29 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. ...
3
votes
2answers
69 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
1answer
62 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 ...
1
vote
1answer
306 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 ...
0
votes
0answers
34 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 ...
0
votes
3answers
197 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 ...
1
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1answer
45 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
57 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 ...
1
vote
1answer
57 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 ...
9
votes
4answers
5k views

Given keys in ~/.ssh/authorized_keys format, can you determine key strength easily?

~/.ssh/authorized_keys[2] contains the list of public keys. Unfortunately, each public key does not specify the key strength ( number of bits ). Is there a utility that can process this file line by ...
1
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0answers
31 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
49 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 ...
14
votes
4answers
13k views

What is the point of sshd “UseDNS” option?

I know what it does, but i don't know why. What attack(s) does it prevent ? Is it relevant for all kind of authentication methods ? (hostbased, password, publickey, keyboard-interactive ...)
2
votes
2answers
117 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 ...
-1
votes
1answer
62 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 ...
0
votes
0answers
116 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 ...
0
votes
1answer
37 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
2answers
46 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
73 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 ...
3
votes
2answers
82 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
31 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 ...
2
votes
3answers
1k views

How to limit ssh access for localhost only?

I need to forbid ssh access (except localhost) for specified user. So. ssh localhost should work. ssh hostname from outside should not work for that user. All other users should work as usual.
3
votes
1answer
155 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 ...
0
votes
0answers
64 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
183 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
124 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 ...
2
votes
2answers
798 views

SSH public key login: two different keys and SSH_AUTH_SOCK behaviour

A user (user1) on an Ubuntu 12.04 desktop has two SSH RSA keys configured: ~/.ssh/id_rsa and ~/.ssh/id_rsa1 (and .pub files). Both public keys are configured in the authorised keys on the server's ...
1
vote
2answers
80 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 ...
2
votes
1answer
104 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
1answer
1k views

how to set the sftp -s subsystem option in a configuration file

The sftp command supports a subsystem option (-s) which allows the remote user to select the remote sftp-server executable, and optionally upgrade to sudo in the process like so; sftp -s ...
6
votes
2answers
253 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 ...
4
votes
2answers
4k 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 ...
1
vote
3answers
10k views

How to ssh to remote server using a private key?

I have two servers. Both servers are in CentOS 5.6. I want to SSH from Server 1 to Server 2 using a private key I have (OpenSSH SSH-2 Private Key). I don't know how to do it over unix. But what I did ...
8
votes
1answer
2k 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 ...
2
votes
1answer
93 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) ...
3
votes
2answers
200 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 ...
11
votes
1answer
2k views

Limits of SSH multiplexing

I have the following entry in my .ssh/config file Host AAA User BBB HostName CCC ControlMaster auto ControlPath ~/.ssh/%r@%h:%p The above allows me to multiplex multiple ssh ...
1
vote
2answers
104 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
72 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
105 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.
5
votes
1answer
105 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 ...
3
votes
2answers
159 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
4answers
724 views

ssh command unexpectedly continues on other system after ssh terminates

I'm running the below command, and monitoring the output file on the other system: ssh $ip_address 'for n in 1 2 3 4 5; do sleep 10; echo $n >>/tmp/count; done' If I kill the ssh command ...
8
votes
2answers
4k 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. ...
12
votes
5answers
559 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
60 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 ...
21
votes
3answers
11k views

Restricting an SSH/SCP/SFTP user to a directory

Is there a simple way to restrict an SCP/SFTP user to a directory? All methods that I've come across require me to set a chroot jail up by copying binaries, but I don't think that should be necessary. ...
2
votes
1answer
78 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.
0
votes
1answer
353 views

non root ssh keys help

I'm having issues setting up a different CentOS account with its own pair of SSH keys. I have created the required files but when connecting with Putty it says Connection refused, here's the putty ...