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. Jul 25, 2019 Execute the following command: ssh-keygen -t rsa (when prompted, enter password, key name can stay the same) Open the file you’ve just created /.ssh/idrsa.pub with your favorite text editor, and copy contents to your Git repository’s keys field (GitHub, beanstalk, or any other repository provider), under your account. Jul 20, 2019 No mention of using a ssh agent (putty pageant on windows) to manage keys. No mention of the benefits of using a smart card (or yubikey) to store and protect your private key further. Simply setting your name and email in your git config doesn't sign your commits, you need gpg for that, again a smart card is the way forward.
Changing the passphase of a key. It is recommended that all SSH keys be regenerated and changed periodically. The Universal SSH Key Manager can automate this. Just changing the passphrase is no substitute, but it is better than nothing. These instructions can also be used to add a passphrase to a key that was created without one. SSH keys are a way to identify trusted computers, without involving passwords. The steps below will walk you through generating an SSH key and adding the public key to the server. Step 1: Check for SSH Keys First, check for existing SSH keys on your computer. Open Git Bash, Cygwin, or Terminal, etc. SSH keys are created using a key generation tool. The SSH command line tool suite includes a keygen tool. Most git hosting providers offer guides on how to create an SSH Key. Generate an SSH Key on Mac and Linux. Both OsX and Linux operating systems have comprehensive modern terminal applications that ship with the SSH suite installed.
-->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 Managers 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:
git remote -v in your Git client.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 Git repos.
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.
The following steps cover configuration of SSH key authentication on the following platforms:
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.
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:
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.
Associate the public key generated in the previous step with your user ID.
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.
Select SSH public keys, and then select + New Key.
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.
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.
Note
To connect with SSH from an existing cloned repo, see updating your remotes to SSH.
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 VSTS is now Azure DevOps Services.
Run git clone from the command prompt.
SSH may display the server's SSH fingerprint and ask you to verify it.
For cloud-hosted Azure DevOps Services, where clone URLs contain either ssh.dev.azure.com or vs-ssh.visualstudio.com, the fingerprint should match one of the following formats:
97:70:33:82:fd:29:3a:73:39:af:6a:07:ad:f8:80:49 (RSA)SHA256:ohD8VZEXGWo6Ez8GSEJQ9WpafgLFsOfLOtGGQCQo6Og (RSA)These fingerprints are also listed in the SSH public keys page.For self-hosted instances of Azure DevOps Server, 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
Avoid trouble: Windows users will need to run a command to have Git reuse their SSH key passphrase.
Host key verification failed.fatal: Could not read from remote repository.
A: Manually record the SSH key by running:ssh-keyscan -t rsa domain.com >> ~/.ssh/known_hosts
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:
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.
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.
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.
A: Azure DevOps Services currently doesn't support LFS over SSH. Use HTTPS to connect to repos with Git LFS tracked files.
A: To use keys created with ssh-keygen in a different place than the default, you do two things:
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. Linux mint generate ssh key. 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.
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:
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.
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.
-->Choose a method to securely access the code in Azure Repos, Azure DevOps Server 2019, or Team Foundation Server (TFS) Git repositories.Use these credentials with Git at a command prompt. These credentials also work with any Git client that supports HTTPS or SSH authentication.Limit the scope of access and revoke these credentials when they're no longer needed.
Important
Azure DevOps no longer supports Alternate Credentials authentication since the beginning of March 2, 2020. If you're still using Alternate Credentials, then they won't work anymore. You have to switch to a more secure authentication method, to mitigate this breaking change impacting your DevOps workflows. Learn more.
Azure DevOps Server was formerly named Visual Studio Team Foundation Server.
Tip
Using Visual Studio? Team Explorer handles authentication with Azure Repos for you.
| Authentication Type | When to use | Secure? | Ease of setup | Additional tools |
|---|---|---|---|---|
| Personal access tokens | You need an easy to configure credential or need configurable access controls | Very secure (when using HTTPS) | Easy | Optional (Git credential managers) |
| SSH | You already have SSH keys set up, or are on macOS or Linux | Very secure | Intermediate | Windows users will need the SSH tools included with Git for Windows |
| Alternate credentials | You can't use personal access tokens or SSH | Least secure | Easy | See important information about alternate credentials |
Personal access tokens (PATs) give you access to Azure DevOps and Team Foundation Server (TFS), without using your username and password directly.These tokens have an expiration date from when they're created. You can restrict the scope of the data they can access.Use PATs to authenticate if you don't already have SSH keys set up on your system or if you need to restrict the permissions that are granted by the credential.
Git credential managers is an optional tool that makes it easy to create PATs when you're working with Azure Repos.Sign in to the web portal, generate a token, and then use the token as your password when you're connecting to Azure Repos.
PATs are generated on demand when you have the credential manager installed.The credential manager creates the token in Azure DevOps and saves it locally for use with the Git command line or other client.
Note
Current versions of Git for Windows include the Git credential manager as an optional feature during installation.
Key authentication with SSH works through a public and private key pair that you create on your computer.You associate the public key with your username from the web. Azure DevOps will encrypt the data sent to you with that key when you work with Git.You decrypt the data on your computer with the private key, which is never shared or sent over the network.
SSH is a great option if you've already got it set up on your system—just add a public key to Azure DevOps and clone your repos using SSH.If you don't have SSH set up on your computer, you should use PATs and HTTPS instead - it's secure and easier to set up.
Learn more about setting up SSH with Azure DevOps
Create an alternate user name and password to access your Git repository using alternate credentials.Unlike PATs, this login doesn't expire and can't be scoped to limit access to your Azure DevOps Services data.Use alternate credentials as a last resort when you can't use PATs or SSH keys.
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