A SSH tunnel consists of an encrypted tunnel created through a SSH protocol connection.A SSH tunnel can be used to transfer unencrypted traffic over a network through an encrypted channel.For example we can use a ssh tunnel to securely transfer files between a FTP server and a client even though the FTP protocol itself is not encrypted. GitHub distributes a simplified Git client for Windows they call GitHub for Windows; it authenticates via GitHub account, and although it usually uses HTTPS remotes for local repositories it creates, if you tell it to use an existing local repository that has an SSH remote on GitHub, it will use your GitHub credentials to set up an SSH key on. Mar 08, 2020 Appendix 1: Installing the Windows Terminal App. You can go directly to the Windows Terminal app store page by running the following command in PowerShell: As is well known, using Windows Terminal. Select Save to store the public key. Once saved, you cannot change the key. You can delete the key or create a new entry for another key. There are no restrictions on how many keys you can add to your user profile. Also note that SSH keys stored in Azure DevOps expire after five years.

• Ssh Specify Username And Password
• Stores Shell

Azure DevOps Services | Azure DevOps Server 2020 | Azure DevOps Server 2019 | TFS 2018 - TFS 2015

Connect to your Git repos through SSH on macOS, Linux, or Windows to securely connect using HTTPS authentication. On Windows, we recommended the use of Git Credential Manager Core or Personal Access Tokens.

Important

SSH URLs have changed, but old SSH URLs will continue to work. If you have already set up SSH, you should update your remote URLs to the new format:

• Verify which remotes are using SSH by running git remote -v in your Git client.
• Visit your repository on the web and select the Clone button in the upper right.
• Select SSH and copy the new SSH URL.
• In your Git client, run: git remote set-url <remote name, e.g. origin> <new SSH URL>. Alternatively, in Visual Studio, go to Repository Settings, and edit your remotes.

Note

As of Visual Studio 2017, SSH can be used to connect to Azure DevOps Git repos.

How SSH key authentication works

SSH public key authentication works with an asymmetric pair of generated encryption keys. The public key is shared with Azure DevOps and used to verify the initial ssh connection. The private key is kept safe and secure on your system.

Set up SSH key authentication

The following steps cover configuration of SSH key authentication on the following platforms:

• Linux
• macOS running at least Leopard (10.5)
• Windows systems running Git for Windows

Configure SSH using the command line. bash is the common shell on Linux and macOS and the Git for Windows installation adds a shortcut to Git Bash in the Start menu.Other shell environments will work, but are not covered in this article.

Step 1: Create your SSH keys

Note

If you have already created SSH keys on your system, skip this step and go to configuring SSH keys.

The commands here will let you create new default SSH keys, overwriting existing default keys. Before continuing, check your~/.ssh folder (for example, /home/jamal/.ssh or C:Usersjamal.ssh) and look for the following files:

• id_rsa
• id_rsa.pub

If these files exist, then you have already created SSH keys. You can overwrite the keys with the following commands, or skip this step and go to configuring SSH keys to reuse these keys.

Create your SSH keys with the ssh-keygen command from the bash prompt. This command will create a 2048-bit RSA key for use with SSH. You can give a passphrasefor your private key when prompted—this passphrase provides another layer of security for your private key.If you give a passphrase, be sure to configure the SSH agent to cache your passphrase so you don't have to enter it every time you connect.

This command produces the two keys needed for SSH authentication: your private key ( id_rsa ) and the public key ( id_rsa.pub ). It is important to never share the contents of your private key. If the private key iscompromised, attackers can use it to trick servers into thinking the connection is coming from you.

Step 2: Add the public key to Azure DevOps Services/TFS

Associate the public key generated in the previous step with your user ID.

1. Open your security settings by browsing to the web portal and selecting your avatar in the upper right of theuser interface. Select SSH public keys in the menu that appears.

2. Select + New Key.

3. Copy the contents of the public key (for example, id_rsa.pub) that you generated into the Public Key Data field.

   Important

   Avoid adding whitespace or new lines into the Key Data field, as they can cause Azure DevOps Services to use an invalid public key. When pasting in the key, a newline often is added at the end. Be sure to remove this newline if it occurs.

4. Give the key a useful description (this description will be displayed on the SSH public keys page for your profile) so that you can remember it later. Select Save to store the public key.Once saved, you cannot change the key. You can delete the key or create a new entry for another key. There are no restrictions on how many keys you can add to your user profile. Also note that SSH keys stored in Azure DevOps expire after five years. If your key expires, you may upload a new key or the same one to continue accessing Azure DevOps via SSH.

5. Test the connection by running the following command: ssh -T git@ssh.dev.azure.com.If everything is working correctly, you'll receive a response which says: remote: Shell access is not supported.If not, see the section on Questions and troubleshooting.

Step 2: Add the public key to Azure DevOps

Associate the public key generated in the previous step with your user ID.

1. Open your security settings by browsing to the web portal and selecting your avatar in the upper right of theuser interface. Select Security in the menu that appears.

2. Select + New Key.

3. Copy the contents of the public key (for example, id_rsa.pub) that you generated into the Public Key Data field.

   Important

   Avoid adding whitespace or new lines into the Key Data field, as they can cause Azure DevOps Services to use an invalid public key. When pasting in the key, a newline often is added at the end. Be sure to remove this newline if it occurs.

4. Give the key a useful description (this description will be displayed on the SSH public keys page for your profile) so that you can remember it later. Select Save to store the public key. Once saved, you cannot change the key. You can delete the key or create a new entry for another key. There are no restrictions on how many keys you can add to your user profile.

5. Test the connection by running the following command: ssh -T git@ssh.dev.azure.com.If everything is working correctly, you'll receive a response which says: remote: Shell access is not supported.If not, see the section on Questions and troubleshooting.

Step 3: Clone the Git repository with SSH

Note

To connect with SSH from an existing cloned repo, see updating your remotes to SSH.

1. Copy the SSH clone URL from the web portal. In this example, the SSL clone URL is for a repo in an organization named fabrikam-fiber, as indicated by the first part of the URL after dev.azure.com.

   Note

   Project URLs have changed with the release of Azure DevOps Services and now have the format dev.azure.com/{your organization}/{your project}, but you can still use the existing visualstudio.com format. For more information, see Visual Studio Team Services is now Azure DevOps Services.

2. Run git clone from the command prompt.

SSH may display the server's SSH fingerprint and ask you to verify it.You should verify that the displayed fingerprint matches one of the fingerprints in the SSH public keys page.

SSH displays this fingerprint when it connects to an unknown host to protect you from man-in-the-middle attacks.Once you accept the host's fingerprint, SSH will not prompt you again unless the fingerprint changes.

When you are asked if you want to continue connecting, type yes. Git will clone the repo and set up the origin remote to connect with SSH for future Git commands.

Tip

To prevent problems, Windows users should run a command to have Git reuse their SSH key passphrase.

Questions and troubleshooting

Q: After running git clone, I get the following error. What should I do?

A: Manually record the SSH key by running:ssh-keyscan -t rsa domain.com >> ~/.ssh/known_hosts

Q: How can I have Git remember the passphrase for my key on Windows?

A: Run the following command included in Git for Windows to start up the ssh-agent process in PowerShell or the Windows Command Prompt. ssh-agent will cacheyour passphrase so you don't have to provide it every time you connect to your repo.

If you're using the Bash shell (including Git Bash), start ssh-agent with:

Q: I use PuTTY as my SSH client and generated my keys with PuTTYgen. Can I use these keys with Azure DevOps Services?

A: Yes. Load the private key with PuTTYgen, go to Conversions menu and select Export OpenSSH key.Save the private key file and then follow the steps to set up non-default keys.Copy your public key directly from the PuTTYgen window and paste into the Key Data field in your security settings.

Q: How can I verify that the public key I uploaded is the same key as I have locally?

A: You can verify the fingerprint of the public key uploaded with the one displayed in your profile through the following ssh-keygen command run against your public key usingthe bash command line. You will need to change the path and the public key filename if you are not using the defaults.

You can then compare the MD5 signature to the one in your profile. This check is useful if you have connection problems or have concerns about incorrectlypasting in the public key into the Key Data field when adding the key to Azure DevOps Services.

Q: How can I start using SSH in a repository where I am currently using HTTPS?

A: You'll need to update the origin remote in Git to change over from a HTTPS to SSH URL. Once you have the SSH clone URL, run the following command:

You can now run any Git command that connects to origin.

Q: I'm using Git LFS with Azure DevOps Services and I get errors when pulling files tracked by Git LFS.

A: Azure DevOps Services currently doesn't support LFS over SSH. Use HTTPS to connect to repos with Git LFS tracked files.

Q: How can I use a non-default key location, i.e. not ~/.ssh/id_rsa and ~/.ssh/id_rsa.pub?

A: To use keys created with ssh-keygen in a different place than the default, perform these two tasks:

1. The keys must be in a folder that only you can read or edit. If the folder has wider permissions, SSH will not use the keys.
2. You must let SSH know the location of the keys. You make SSH aware of keys through the ssh-add command, providing the full path to the private key.

On Windows, before running ssh-add, you will need to run the following command from included in Git for Windows:

This command runs in both PowerShell and the Command Prompt. If you are using Git Bash, the command you need to use is:

You can find ssh-add as part of the Git for Windows distribution and also run it in any shell environment on Windows.

On macOS and Linux you also must have ssh-agent running before running ssh-add, but the command environment on these platforms usuallytakes care of starting ssh-agent for you.

Q: I have multiple SSH keys. How do I use different SSH keys for different SSH servers or repos?

A: Generally, if you configure multiple keys for an SSH client and connect to an SSH server, the client can try the keys one at a time until the server accepts one.

However, this doesn't work with Azure DevOps for technical reasons related to the SSH protocol and how our Git SSH URLs are structured. Azure DevOps will blindly accept the first key that the client provides during authentication. If that key is invalid for the requested repo, the request will fail with the following error:

For Azure DevOps, you'll need to configure SSH to explicitly use a specific key file. One way to do this to edit your ~/.ssh/config file (for example, /home/jamal/.ssh or C:Usersjamal.ssh) as follows:

Q: How do I fix errors that mention 'no matching key exchange method found'?

A: Git for Windows 2.25.1 shipped with a new version of OpenSSH which removed some key exchange protocols by default.Specifically, diffie-hellman-group14-sha1 has been identified as problematic for some Azure DevOps Server and TFS customers.You can work around the problem by adding the following to your SSH configuration (~/.ssh/config):

Replace <your-azure-devops-host> with the hostname of your Azure DevOps or TFS server, like tfs.mycompany.com.

Q: What notifications may I receive about my SSH keys?

A: Whenever you register a new SSH Key with Azure DevOps Services, you will receive an email notification informing you that a new SSH key has been added to your account.

Q: What do I do if I believe that someone other than me is adding SSH keys on my account?

A: If you receive a notification of an SSH key being registered and you did not manually upload it to the service, your credentials may have been compromised.

The next step would be to investigate whether or not your password has been compromised. Changing your password is always a good first step to defend against this attack vector. If you’re an Azure Active Directory user, talk with your administrator to check if your account was used from an unknown source/location.

Q: What do I do if I'm still prompted for my password and GIT_SSH_COMMAND='ssh -v' git fetch shows no mutual signature algorithm?

A: Some Linux distributions, such as Fedora Linux, have crypto policies that require stronger SSH signature algorithms than Azure DevOps supports (as of January 2021). There's an open feature request to add this support.

You can work around the issue by adding the following code to your SSH configuration (~/.ssh/config):

Replace ssh.dev.azure.com with the correct host name if you use Azure DevOps Server.

This tutorial walks you through creating and connecting to a virtual machine (VM) on Azure using the Visual Studio Code Remote - SSH extension. You'll create a Node.js Express web app to show how you can edit and debug on a remote machine with VS Code just like you could if the source code was local.

Note: Your Linux VM can be hosted anywhere - on your local host, on premise, in Azure, or in any other cloud, as long as the chosen Linux distribution meets these prerequisites.

Prerequisites

To get started, you need to have done the following steps:

1. Install an OpenSSH compatible SSH client (PuTTY is not supported).
2. Install Visual Studio Code.
3. Have an Azure subscription (If you don't have an Azure subscription, create a free account before you begin).

Install the extension

The Remote - SSH extension is used to connect to SSH hosts.

Remote - SSH

With the Remote - SSH extension installed, you will see a new Status bar item at the far left.

The Remote Status bar item can quickly show you in which context VS Code is running (local or remote) and clicking on the item will bring up the Remote - SSH commands.

Create a virtual machine

If you don't have an existing Linux virtual machine, you can create a new VM through the Azure portal. In the Azure portal, search for 'Virtual Machines', and choose Add. From there, you can select your Azure subscription and create a new resource group, if you don't already have one.

Note: In this tutorial, we are using Azure, but your Linux VM can be hosted anywhere, as long as the Linux distribution meets these prerequisites.

Now you can specify details of your VM, such as the name, the size, and the base image. Choose Ubuntu Server 18.04 LTS for this example, but you can choose recent versions of other Linux distros and look at VS Code's supported SSH servers.

Set up SSH

There are several authentication methods into a VM, including an SSH public/private key pair or a username and password. We strongly recommend using key-based authentication (if you use a username/password, you'll be prompted to enter your credentials more than once by the extension). If you're on Windows and have already created keys using PuttyGen, you can reuse them.

Create an SSH key

If you don't have an SSH key pair, open a bash shell or the command line and type in:

This will generate the SSH key. Press Enter at the following prompt to save the key in the default location (under your user directory as a folder named .ssh).

You will then be prompted to enter a secure passphrase, but you can leave that blank. You should now have a id_rsa.pub file which contains your new public SSH key.

Add SSH key to your VM

In the previous step, you generated an SSH key pair. Select Use existing public key in the dropdown for SSH public key source so that you can use the public key you just generated. Take the public key and paste it into your VM setup, by copying the entire contents of the id_rsa.pub in the SSH public key. You also want to allow your VM to accept inbound SSH traffic by selecting Allow selected ports and choosing SSH (22) from the Select inbound ports dropdown list.

Auto shutdown

A cool feature of using Azure VMs is the ability to enable auto shutdown (because let's face it, we all forget to turn off our VMs…). If you go to the Management tab, you can set the time you want to shut down the VM daily.

Select Review and Create, then Create, and Azure will deploy your VM for you!

Once the deployment is finished (it may take several minutes), go to the new resource view for your virtual machine.

Connect using SSH

Now that you've created an SSH host, let's connect to it!

You'll have noticed an indicator on the bottom-left corner of the Status bar. This indicator tells you in which context VS Code is running (local or remote). Click on the indicator to bring up a list of Remote extension commands.

Choose the Remote-SSH: Connect to Host command and connect to the host by entering connection information for your VM in the following format: user@hostname.

The user is the username you set when adding the SSH public key to your VM. For the hostname, go back to the Azure portal and in the Overview pane of the VM you created, copy the Public IP address.

Before connecting in Remote - SSH, you can verify you're able to connect to your VM via a command prompt using ssh user@hostname.

Note: If you run into an error ssh: connect to host <host ip> port 22: Connection timed out, you may need to delete NRMS-Rule-106 from the Networking tab of your VM:

Set the user and hostname in the connection information text box.

VS Code will now open a new window (instance). You'll then see a notification that the 'VS Code Server' is initializing on the SSH Host. Once the VS Code Server is installed on the remote host, it can run extensions and talk to your local instance of VS Code.

You'll know you're connected to your VM by looking at the indicator in the Status bar. It shows the hostname of your VM.

The Remote - SSH extension also contributes a new icon on your Activity bar, and clicking on it will open the Remote explorer. From the dropdown, select SSH Targets, where you can configure your SSH connections. For instance, you can save the hosts you connect to the most and access them from here instead of entering the user and hostname.

Once you're connected to your SSH host, you can interact with files and open folders on the remote machine. If you open the integrated terminal (⌃` (Windows, Linux Ctrl+`)), you'll see you're working inside a bash shell while you're on Windows.

You can use the bash shell to browse the file system on the VM. You can also browse and open folders on the remote home directory with File > Open Folder.

Create your Node.js application

In this step, you will create a simple Node.js application. You will use an application generator to quickly scaffold out the application from a terminal.

Install Node.js and npm

From the integrated terminal (⌃` (Windows, Linux Ctrl+`)), update the packages in your Linux VM, then install Node.js, which includes npm, the Node.js package manager.

Ssh Specify Username And Password

You can verify the installations by running:

Install the Express generator

Express is a popular framework for building and running Node.js applications. You can scaffold (create) a new Express application using the Express Generator tool. The Express Generator is shipped as an npm module and installed by using the npm command-line tool npm.

The -g switch installs the Express Generator globally on your machine so that you can run it from anywhere.

Create a new application

You can now create a new Express application called myExpressApp by running:

The --view pug parameters tell the generator to use the pug template engine.

To install all of the application's dependencies, go to the new folder and run npm install.

Run the application

Last, let's ensure that the application runs. From the terminal, start the application using the npm start command to start the server.

The Express app by default runs on http://localhost:3000. You won't see anything in your local browser on localhost:3000 because the web app is running on your virtual machine.

Port forwarding

To be able to browse to the web app on your local machine, you can leverage another feature called Port forwarding.

To be able to access a port on the remote machine that may not be publicly exposed, you need to establish a connection or a tunnel between a port on your local machine and the server. With the app still running, open the SSH Explorer and find the Forwarded Ports view. Click on the Forward a port link and indicate that you want to forward port 3000:

Name the connection 'browser':

The server will now forward traffic on port 3000 to your local machine. When you browse to http://localhost:3000, you see the running web app.

Edit and debug

From the Visual Studio Code File Explorer (⇧⌘E (Windows, Linux Ctrl+Shift+E)), navigate to your new myExpressApp folder and double-click the app.js file to open it in the editor.

IntelliSense

You have syntax highlighting for the JavaScript file as well as IntelliSense with hovers, just like you would see if the source code was on your local machine.

When you start typing, you'll get smart completions for the object methods and properties.

Debugging

Stores Shell

Set a breakpoint on line 10 of app.js by clicking in the gutter to the left of the line number or by putting the cursor on the line and pressing F9. The breakpoint will be displayed as a red circle.

Now, press F5 to run your application. If you are asked how to run the application, choose Node.js.

The app will start, and you'll hit the breakpoint. You can inspect variables, create watches, and navigate the call stack.

Press F10 to step or F5 again to finish your debugging session.

You get the full development experience of Visual Studio Code connected over SSH.

Ending your SSH connection

You can end your session over SSH and go back to running VS Code locally with File > Close Remote Connection.

Congratulations!

Congratulations, you've successfully completed this tutorial!

Next, check out the other Remote Development extensions.

Or get them all by installing the Remote Development Extension Pack.