| title | titleSuffix | description | ms.assetid | ms.technology | ms.topic | ms.date | monikerRange |
|---|---|---|---|---|---|---|---|
Connect to your Git repos with SSH |
Azure Repos |
Authenticate to Azure Repos Git Repositories with SSH Keys |
2f89b7e9-3d10-4293-a277-30e26cae54c5 |
devops-code-git |
conceptual |
08/25/2020 |
>= tfs-2015 |
[!INCLUDE version-ts-tfs-2015-2016]
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:
- Verify which remotes are using SSH by running
git remote -vin 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 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:
- 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.
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:\Users\jamal\.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 passphrase
for 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.
$ ssh-keygen -C "jamal@fabrikam.com"
Generating public/private rsa key pair.
Enter file in which to save the key (/c/Users/jamal/.ssh/id_rsa):
Enter passphrase (empty for no passphrase):
Enter same passphrase again:
Your identification has been saved in /c/Users/jamal/.ssh/id_rsa.
Your public key has been saved in /c/Users/jamal/.ssh/id_rsa.pub.
The key fingerprint is:
SHA256:******************************************* jamal@fabrikam.com
The key's randomart image is:
+---[RSA 2048]----+
|+. +yX*o . |
|... ..E+*=o |
| ..o.=E=.o |
| . * =.o . |
| . S o o.. |
| + .oo |
| S+. . |
| ..+.+ |
| o*.. |
+----[SHA256]-----+
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 is compromised, 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 the user 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.
-
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.
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.
[!INCLUDE project-urls]
-
Run
git clonefrom the command prompt.git clone git@ssh.dev.azure.com:v3/fabrikam-fiber/FabrikamFiber/FabrikamFiber
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.
$ git clone git@ssh.dev.azure.com:v3/fabrikam-fiber/FabrikamFiber/FabrikamFiber
Cloning into 'FabrikamFiber'...
The authenticity of host 'ssh.dev.azure.com (65.52.8.37)' can't be established.
RSA key fingerprint is SHA256:********************************************
Are you sure you want to continue connecting (yes/no)? yes
Warning: Permanently added 'ssh.dev.azure.com,65.52.8.37' (RSA) to the list of known hosts.
Enter passphrase for key '/c/Users/jamal/.ssh/id_rsa':
remote: Azure Repos
remote: Found 127 objects to send. (50 ms)
Receiving objects: 100% (127/127), 56.67 KiB | 2.58 MiB/s, done.
Resolving deltas: 100% (15/15), done.
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 cache
your passphrase so you don't have to provide it every time you connect to your repo.
start-ssh-agent.cmd
If you're using the Bash shell (including Git Bash), start ssh-agent with:
eval `ssh-agent`
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.
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 using
the bash command line. You will need to change the path and the public key filename if you are not using the defaults.
ssh-keygen -l -E md5 -f ~/.ssh/id_rsa.pub
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 incorrectly pasting 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:
git remote set-url origin git@ssh.dev.azure.com:v3/fabrikam-fiber/FabrikamFiber/FabrikamFiber
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.
A: To use keys created with ssh-keygen in a different place than the default, you do two things:
- 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.
- You must let SSH know the location of the keys. You make SSH aware of keys through the
ssh-addcommand, providing the full path to the private key.
ssh-add /home/jamal/.ssh/id_jamal.rsa
On Windows, before running ssh-add, you will need to run the following command from included in Git for Windows:
start-ssh-agent.cmd
This command runs in both PowerShell and the Command Prompt. If you are using Git Bash, the command you need to use is:
eval `ssh-agent`
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 usually
takes 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:
remote: Public key authentication failed. fatal: Could not read from remote repository.
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:\Users\jamal\.ssh) as follows:
::: moniker range="= azure-devops"
# The settings in each Host section are applied to any Git SSH remote URL with a
# matching hostname.
# Generally:
# * SSH uses the first matching line for each parameter name, e.g. if there's
# multiple values for a parameter across multiple matching Host sections
# * "IdentitiesOnly yes" prevents keys cached in ssh-agent from being tried before
# the IdentityFile values we explicitly set.
# * On Windows, ~/.ssh/your_private_key maps to %USERPROFILE%\.ssh\your_private_key,
# e.g. C:\Users\<username>\.ssh\your_private_key.
# Most common scenario: to use the same key across all hosted Azure DevOps
# organizations, add a Host entry like this:
Host ssh.dev.azure.com
IdentityFile ~/.ssh/your_private_key
IdentitiesOnly yes
# This model will also work if you still use the older SSH URLs with a
# hostname of vs-ssh.visualstudio.com:
Host vs-ssh.visualstudio.com
IdentityFile ~/.ssh/your_private_key
IdentitiesOnly yes
# Less common scenario: if you need different keys for different organizations,
# you'll need to use host aliases to create separate Host sections.
# This is because all hosted Azure DevOps URLs have the same hostname
# (ssh.dev.azure.com), so SSH has no way to distinguish them by default.
#
# Imagine that we have the following two SSH URLs:
# * git@ssh.dev.azure.com:v3/Fabrikam/Project1/fab_repo
# * For this, we want to use `fabrikamkey`, so we'll create `devops_fabrikam` as
# a Host alias and tell SSH to use `fabrikamkey`.
# * git@ssh.dev.azure.com:v3/Contoso/Project2/con_repo
# * For this, we want to use `contosokey`, so we'll create `devops_contoso` as
# a Host alias and tell SSH to use `contosokey`.
#
# To set explicit keys for the two host aliases and to tell SSH to use the correct
# actual hostname, add the next two Host sections:
Host devops_fabrikam
HostName ssh.dev.azure.com
IdentityFile ~/.ssh/private_key_for_fabrikam
IdentitiesOnly yes
Host devops_contoso
HostName ssh.dev.azure.com
IdentityFile ~/.ssh/private_key_for_contoso
IdentitiesOnly yes
#
# Then, instead of using the real URLs, tell Git you want to use these URLs:
# * git@devops_fabrikam:v3/Fabrikam/Project1/fab_repo
# * git@devops_contoso:v3/Contoso/Project2/con_repo
#
# At the end of the file, you can put global defaults for other SSH hosts you
# may connect to. Note that "*" also matches any hosts that match the sections
# above, and remember that SSH uses the first matching line for each parameter name.
Host *
::: moniker-end
::: moniker range="< azure-devops"
# The settings in each Host section are applied to any Git SSH remote URL with a
# matching hostname.
# Generally:
# * SSH uses the first matching line for each parameter name, e.g. if there's
# multiple values for a parameter across multiple matching Host sections
# * "IdentitiesOnly yes" prevents keys cached in ssh-agent from being tried before
# the IdentityFile values we explicitly set.
# * On Windows, ~/.ssh/your_private_key maps to %USERPROFILE%\.ssh\your_private_key,
# e.g. C:\Users\<username>\.ssh\your_private_key.
# Say your on-premises Azure DevOps Server instance has SSH URLs like this:
# ssh://someHost:22/someCollection/some_project/_git/some_repo
# Add the following Host section:
Host someHost
IdentityFile ~/.ssh/your_private_key
IdentitiesOnly yes
# At the end of the file, you can put global defaults for other SSH hosts you
# may connect to. Note that "*" also matches any hosts that match the sections
# above, and remember that SSH uses the first matching line for each parameter name.
Host *
::: moniker-end
::: moniker range="<= azure-devops-2019"
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):
Host <your-azure-devops-host>
KexAlgorithms +diffie-hellman-group14-sha1
Replace <your-azure-devops-host> with the hostname of your Azure DevOps or TFS server, like tfs.mycompany.com.
::: moniker-end
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.