1. Ssh Service Linux
2. Ubuntu Enable Ssh Service
3. Ssh Service Is Masked

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Applies to Windows Server 2019, Windows 10

See full list on docs.microsoft.com. SSH is a software package that enables secure system administration and file transfers over insecure networks. It is used in nearly every data center and in every large enterprise. This page was created by the inventor of SSH, Tatu Ylonen (twitter: @tjssh). He wrote ssh-1.x and ssh-2.x, and still works on related topics.

OpenSSH is a connectivity tool for remote login that uses the SSH protocol. It encrypts all traffic between client and server to eliminate eavesdropping, connection hijacking, and other attacks.

OpenSSH can be used to connect Window 10 clients to Windows Server 2019. OpenSSH Client is available to install on Windows 10 build 1809 and later, while OpenSSH Server is available to install on Windows Server 2019 and later.

Important

If you downloaded OpenSSH from the GitHub repo at PowerShell/openssh-portable, follow the instructions listed there, not the ones in this article.

Install OpenSSH using Windows Settings

Both OpenSSH components can be installed using Windows Settings. OpenSSH Server is installed on Windows Server and OpenSSH Client is installed on Windows 10 devices.

To install the OpenSSH components:

1. Open Settings, select Apps > Apps & Features, then select Optional Features.

2. Scan the list to see if the OpenSSH is already installed. If not, at the top of the page, select Add a feature, then:

   • On Windows 10, find OpenSSH Client, then click Install
   • On Windows Server 2019, find OpenSSH Server, then click Install

Once setup completes, return to Apps > Apps & Features and Optional Features and you should see OpenSSH listed.

Note

Installing OpenSSH Server will create and enable a firewall rule named OpenSSH-Server-In-TCP. This allows inbound SSH traffic on port 22. If this rule is not enabled and this port is not open, connections will be refused or reset.

Install OpenSSH using PowerShell

To install OpenSSH using PowerShell, run PowerShell as an Administrator.To make sure that OpenSSH is available, run the following cmdlet:

This should return the following output:

Then, install the server or client components as needed:

Ssh Service Linux

Both of these should return the following output:

Start and configure SSH Server

To start and configure OpenSSH server for initial use, open PowerShell as an administrator, then run the following commands to start the SSHD service:

Connect to SSH Server

Once installed, you can connect to OpenSSH Server from a Windows 10 device with the SSH client installed using PowerShell as follows. Be sure to run PowerShell as an administrator:

Once connected, you get a message similar to the following:

Selecting yes adds that server to the list of known ssh hosts on your Windows client.

You are prompted for the password at this point. As a security precaution, your password will not be displayed as you type.

Once connected, you will see the Windows command shell prompt:

Uninstall OpenSSH using Windows Settings

To uninstall OpenSSH using Windows Settings:

1. Open Settings, then go to Apps > Apps & Features.
2. Go to Optional Features.
3. In the list, select OpenSSH Client or OpenSSH Server.
4. Select Uninstall.

Uninstall OpenSSH using PowerShell

To uninstall the OpenSSH components using PowerShell, use the following commands:

You may need to restart Windows afterwards if the service was in use at the time it was uninstalled.

Introduction

OpenSSH is a powerful collection of tools for the remote control of, and transfer of data between, networked computers. You will also learn about some of the configuration settings possible with the OpenSSH server application and how to change them on your Ubuntu system.

OpenSSH is a freely available version of the Secure Shell (SSH) protocol family of tools for remotely controlling, or transferring files between, computers. Traditional tools used to accomplish these functions, such as telnet or rcp, are insecure and transmit the user’s password in cleartext when used. OpenSSH provides a server daemon and client tools to facilitate secure, encrypted remote control and file transfer operations, effectively replacing the legacy tools.

The OpenSSH server component, sshd, listens continuously for client connections from any of the client tools. When a connection request occurs, sshd sets up the correct connection depending on the type of client tool connecting. For example, if the remote computer is connecting with the ssh client application, the OpenSSH server sets up a remote control session after authentication. If a remote user connects to an OpenSSH server with scp, the OpenSSH server daemon initiates a secure copy of files between the server and client after authentication. OpenSSH can use many authentication methods, including plain password, public key, and Kerberos tickets.

Installation

Installation of the OpenSSH client and server applications is simple. To install the OpenSSH client applications on your Ubuntu system, use this command at a terminal prompt:

To install the OpenSSH server application, and related support files, use this command at a terminal prompt:

Configuration

You may configure the default behavior of the OpenSSH server application, sshd, by editing the file /etc/ssh/sshd_config. For information about the configuration directives used in this file, you may view the appropriate manual page with the following command, issued at a terminal prompt:

There are many directives in the sshd configuration file controlling such things as communication settings, and authentication modes. The following are examples of configuration directives that can be changed by editing the /etc/ssh/sshd_config file.

Tip

Prior to editing the configuration file, you should make a copy of the original file and protect it from writing so you will have the original settings as a reference and to reuse as necessary.

Copy the /etc/ssh/sshd_config file and protect it from writing with the following commands, issued at a terminal prompt:

Furthermore since losing an ssh server might mean losing your way to reach a server, check the configuration after changing it and before restarting the server:

The following are examples of configuration directives you may change:

• To set your OpenSSH to listen on TCP port 2222 instead of the default TCP port 22, change the Port directive as such:

Port 2222

• To make your OpenSSH server display the contents of the /etc/issue.net file as a pre-login banner, simply add or modify this line in the /etc/ssh/sshd_config file:

Banner /etc/issue.net

After making changes to the /etc/ssh/sshd_config file, save the file, and restart the sshd server application to effect the changes using the following command at a terminal prompt:

Warning

Many other configuration directives for sshd are available to change the server application’s behavior to fit your needs. Be advised, however, if your only method of access to a server is ssh, and you make a mistake in configuring sshd via the /etc/ssh/sshd_config file, you may find you are locked out of the server upon restarting it. Additionally, if an incorrect configuration directive is supplied, the sshd server may refuse to start, so be extra careful when editing this file on a remote server.

SSH Keys

SSH allow authentication between two hosts without the need of a password. SSH key authentication uses a private key and a public key.

To generate the keys, from a terminal prompt enter:

This will generate the keys using the RSA Algorithm. At the time of this writing, the generated keys will have 3072 bits. You can modify the number of bits by using the -b option. For example, to generate keys with 4096 bits, you can do:

During the process you will be prompted for a password. Simply hit Enter when prompted to create the key.

By default the public key is saved in the file ~/.ssh/id_rsa.pub, while ~/.ssh/id_rsa is the private key. Now copy the id_rsa.pub file to the remote host and append it to ~/.ssh/authorized_keys by entering:

Finally, double check the permissions on the authorized_keys file, only the authenticated user should have read and write permissions. If the permissions are not correct change them by:

You should now be able to SSH to the host without being prompted for a password.

Import keys from public keyservers

These days many users have already ssh keys registered with services like launchpad or github. Those can be easily imported with:

The prefix lp: is implied and means fetching from launchpad, the alternative gh: will make the tool fetch from github instead.

Two factor authentication with U2F/FIDO

OpenSSH 8.2 added support for U2F/FIDO hardware authentication devices. These devices are used to provide an extra layer of security on top of the existing key-based authentication, as the hardware token needs to be present to finish the authentication.

It’s very simple to use and setup. The only extra step is generate a new keypair that can be used with the hardware device. For that, there are two key types that can be used: ecdsa-sk and ed25519-sk. The former has broader hardware support, while the latter might need a more recent device.

Once the keypair is generated, it can be used as you would normally use any other type of key in openssh. The only requirement is that in order to use the private key, the U2F device has to be present on the host.

For example, plug the U2F device in and generate a keypair to use with it:

Now just transfer the public part to the server to ~/.ssh/authorized_keys and you are ready to go:

References

Ubuntu Enable Ssh Service

• Ubuntu Wiki SSH page.

Ssh Service Is Masked

Last updated 8 months ago. Help improve this document in the forum.