Gitlab add ssh key windows 10

GitLab and SSH keys

Git is a distributed version control system, which means you can work locally
but you can also share or «push» your changes to other servers.
Before you can push your changes to a GitLab server
you need a secure communication channel for sharing information.

The SSH protocol provides this security and allows you to authenticate to the
GitLab remote server without supplying your username or password each time.

For a more detailed explanation of how the SSH protocol works, read
this nice tutorial by DigitalOcean.

Requirements

The only requirement is to have the OpenSSH client installed on your system. This
comes pre-installed on GNU/Linux and macOS, but not on Windows.

Depending on your Windows version, there are different methods to work with
SSH keys.

Installing the SSH client for Windows 10

Starting with Windows 10, you can
install the Windows Subsystem for Linux (WSL)
where you can run Linux distributions directly on Windows, without the overhead
of a virtual machine. Once installed and set up, you’ll have the Git and SSH
clients at your disposal.

Installing the SSH client for Windows 8.1 and Windows 7

The easiest way to install Git and the SSH client on Windows 8.1 and Windows 7
is Git for Windows. It provides a BASH
emulation (Git Bash) used for running Git from the command line and the
ssh-keygen command that is useful to create SSH keys as you’ll learn below.

NOTE: Alternative tools:
Although not explored in this page, you can use some alternative tools.
Cygwin is a large collection of GNU and open source
tools which provide functionality similar to a Unix distribution.
PuttyGen
provides a graphical user interface to create SSH keys.

Types of SSH keys and which to choose

GitLab supports RSA, DSA, ECDSA, and ED25519 keys. Their difference lies on
the signing algorithm, and some of them have advantages over the others. For
more information, you can read this
nice article on ArchWiki.
We’ll focus on ED25519 and RSA and here.

NOTE: Note:
As an admin, you can restrict
which keys should be permitted and their minimum length.
By default, all keys are permitted, which is also the case for
GitLab.com.

ED25519 SSH keys

Following best practices,
you should always favor ED25519 SSH keys, since they
are more secure and have better performance over the other types.

They were introduced in OpenSSH 6.5, so any modern OS should include the
option to create them. If for any reason your OS or the GitLab instance you
interact with doesn’t support this, you can fallback to RSA.

RSA SSH keys

RSA keys are the most common ones and therefore the most compatible with
servers that may have an old OpenSSH version. Use them if the GitLab server
doesn’t work with ED25519 keys.

The minimum key size is 1024 bits, defaulting to 2048. If you wish to generate a
stronger RSA key pair, specify the -b flag with a higher bit value than the
default.

The old, default password encoding for SSH private keys is
insecure;
it’s only a single round of an MD5 hash. Since OpenSSH version 6.5, you should
use the -o option to ssh-keygen to encode your private key in a new, more
secure format.

If you already have an RSA SSH key pair to use with GitLab, consider upgrading it
to use the more secure password encryption format by using the following command
on the private key:

ssh-keygen -o -f ~/.ssh/id_rsa

Generating a new SSH key pair

Before creating an SSH key pair, make sure to read about the
different types of keys to understand
their differences.

To create a new SSH key pair:

1. Open a terminal on Linux or macOS, or Git Bash / WSL on Windows.

2. Generate a new ED25519 SSH key pair:

   ssh-keygen -t ed25519 -C "email@example.com"

   Or, if you want to use RSA:

   ssh-keygen -o -t rsa -b 4096 -C "email@example.com"

   The -C flag adds a comment in the key in case you have multiple of them
   and want to tell which is which. It is optional.

3. Next, you will be prompted to input a file path to save your SSH key pair to.
   If you don’t already have an SSH key pair, use the suggested path by pressing
   Enter. Using the suggested path will normally allow your SSH client
   to automatically use the SSH key pair with no additional configuration.

   If you already have an SSH key pair with the suggested file path, you will need
   to input a new file path and declare what host
   this SSH key pair will be used for in your ~/.ssh/config file.

4. Once the path is decided, you will be prompted to input a password to
   secure your new SSH key pair. It’s a best practice to use a password,
   but it’s not required and you can skip creating it by pressing
   Enter twice.

   If, in any case, you want to add or change the password of your SSH key pair,
   you can use the -pflag:

   ssh-keygen -p -o -f <keyname>

Now, it’s time to add the newly created public key to your GitLab account.

Adding an SSH key to your GitLab account

1. Copy your public SSH key to the clipboard by using one of the commands below
   depending on your Operating System:

   macOS:

   pbcopy < ~/.ssh/id_ed25519.pub

   WSL / GNU/Linux (requires the xclip package):

   xclip -sel clip < ~/.ssh/id_ed25519.pub

   Git Bash on Windows:

   cat ~/.ssh/id_ed25519.pub | clip

   You can also open the key in a graphical editor and copy it from there,
   but be careful not to accidentally change anything.

   NOTE: Note:
   If you opted to create an RSA key, the name might differ.

2. Add your public SSH key to your GitLab account by clicking your avatar
   in the upper right corner and selecting Settings. From there on,
   navigate to SSH Keys and paste your public key in the «Key» section.
   If you created the key with a comment, this will appear under «Title».
   If not, give your key an identifiable title like Work Laptop or
   Home Workstation, and click Add key.

   NOTE: Note:
   If you manually copied your public SSH key make sure you copied the entire
   key starting with ssh-ed25519 (or ssh-rsa) and ending with your email.

Testing that everything is set up correctly

To test whether your SSH key was added correctly, run the following command in
your terminal (replacing gitlab.com with your GitLab’s instance domain):

ssh -T git@gitlab.com

The first time you connect to GitLab via SSH, you will be asked to verify the
authenticity of the GitLab host you are connecting to.
For example, when connecting to GitLab.com, answer yes to add GitLab.com to
the list of trusted hosts:

The authenticity of host 'gitlab.com (35.231.145.151)' can't be established.
ECDSA key fingerprint is SHA256:HbW3g8zUjNSksFbqTiUWPWg2Bq1x8xdGUrliXFzSnUw.
Are you sure you want to continue connecting (yes/no)? yes
Warning: Permanently added 'gitlab.com' (ECDSA) to the list of known hosts.

NOTE: Note:
For GitLab.com, consult the
SSH host keys fingerprints,
to make sure you’re connecting to the correct server.

Once added to the list of known hosts, you won’t be asked to validate the
authenticity of GitLab’s host again. Run the above command once more, and
you should only receive a Welcome to GitLab, @username! message.

If the welcome message doesn’t appear, run SSH’s verbose mode by replacing -T
with -vvvT to understand where the error is.

Working with non-default SSH key pair paths

If you used a non-default file path for your GitLab SSH key pair,
you must configure your SSH client to find your GitLab private SSH key
for connections to GitLab.

Open a terminal and use the following commands
(replacing other_id_rsa with your private SSH key):

eval $(ssh-agent -s)
ssh-add ~/.ssh/other_id_rsa

To retain these settings, you’ll need to save them to a configuration file.
For OpenSSH clients this is configured in the ~/.ssh/config file. In this
file you can set up configurations for multiple hosts, like GitLab.com, your
own GitLab instance, GitHub, Bitbucket, etc.

Below are two example host configurations using their own SSH key:

# GitLab.com
Host gitlab.com
  Preferredauthentications publickey
  IdentityFile ~/.ssh/gitlab_com_rsa

# Private GitLab instance
Host gitlab.company.com
  Preferredauthentications publickey
  IdentityFile ~/.ssh/example_com_rsa

Public SSH keys need to be unique to GitLab, as they will bind to your account.
Your SSH key is the only identifier you’ll have when pushing code via SSH,
that’s why it needs to uniquely map to a single user.

Per-repository SSH keys

If you want to use different keys depending on the repository you are working
on, you can issue the following command while inside your repository:

git config core.sshCommand "ssh -o IdentitiesOnly=yes -i ~/.ssh/private-key-filename-for-this-repository -F /dev/null"

This will not use the SSH Agent and requires at least Git 2.10.

Deploy keys

Per-repository deploy keys

Deploy keys allow read-only or read-write (if enabled) access to one or
multiple projects with a single SSH key pair.

This is really useful for cloning repositories to your Continuous
Integration (CI) server. By using deploy keys, you don’t have to set up a
dummy user account.

If you are a project maintainer or owner, you can add a deploy key in the
project settings under the section ‘Repository’. Specify a title for the new
deploy key and paste a public SSH key. After this, the machine that uses
the corresponding private SSH key has read-only or read-write (if enabled)
access to the project.

You can’t add the same deploy key twice using the form.
If you want to add the same key to another project, please enable it in the
list that says ‘Deploy keys from projects available to you’. All the deploy
keys of all the projects you have access to are available. This project
access can happen through being a direct member of the project, or through
a group.

Deploy keys can be shared between projects, you just need to add them to each
project.

Global shared deploy keys

Global Shared Deploy keys allow read-only or read-write (if enabled) access to
be configured on any repository in the entire GitLab installation.

This is really useful for integrating repositories to secured, shared Continuous
Integration (CI) services or other shared services.
GitLab administrators can set up the Global Shared Deploy key in GitLab and
add the private key to any shared systems. Individual repositories opt into
exposing their repository using these keys when a project maintainers (or higher)
authorizes a Global Shared Deploy key to be used with their project.

Global Shared Keys can provide greater security compared to Per-Project Deploy
Keys since an administrator of the target integrated system is the only one
who needs to know and configure the private key.

GitLab administrators set up Global Deploy keys in the Admin area under the
section Deploy Keys. Ensure keys have a meaningful title as that will be
the primary way for project maintainers and owners to identify the correct Global
Deploy key to add. For instance, if the key gives access to a SaaS CI instance,
use the name of that service in the key name if that is all it is used for.
When creating Global Shared Deploy keys, give some thought to the granularity
of keys — they could be of very narrow usage such as just a specific service or
of broader usage for something like «Anywhere you need to give read access to
your repository».

Once a GitLab administrator adds the Global Deployment key, project maintainers
and owners can add it in project’s Settings > Repository section by expanding the
Deploy Key section and clicking Enable next to the appropriate key listed
under Public deploy keys available to any project.

NOTE: Note:
The heading Public deploy keys available to any project only appears
if there is at least one Global Deploy Key configured.

CAUTION: Warning:
Defining Global Deploy Keys does not expose any given repository via
the key until that repository adds the Global Deploy Key to their project.
In this way the Global Deploy Keys enable access by other systems, but do
not implicitly give any access just by setting them up.

Applications

Eclipse

How to add your SSH key to Eclipse: https://wiki.eclipse.org/EGit/User_Guide#Eclipse_SSH_Configuration

SSH on the GitLab server

GitLab integrates with the system-installed SSH daemon, designating a user
(typically named git) through which all access requests are handled. Users
connecting to the GitLab server over SSH are identified by their SSH key instead
of their username.

SSH client operations performed on the GitLab server wil be executed as this
user. Although it is possible to modify the SSH configuration for this user to,
e.g., provide a private SSH key to authenticate these requests by, this practice
is not supported and is strongly discouraged as it presents significant
security risks.

The GitLab check process includes a check for this condition, and will direct you
to this section if your server is configured like this, e.g.:

$ gitlab-rake gitlab:check
# ...
Git user has default SSH configuration? ... no
  Try fixing it:
  mkdir ~/gitlab-check-backup-1504540051
  sudo mv /var/lib/git/.ssh/id_rsa ~/gitlab-check-backup-1504540051
  sudo mv /var/lib/git/.ssh/id_rsa.pub ~/gitlab-check-backup-1504540051
  For more information see:
  doc/ssh/README.md in section "SSH on the GitLab server"
  Please fix the error above and rerun the checks.

Remove the custom configuration as soon as you’re able to. These customizations
are explicitly not supported and may stop working at any time.

Troubleshooting

If on Git clone you are prompted for a password like git@gitlab.com's password:
something is wrong with your SSH setup.

• Ensure that you generated your SSH key pair correctly and added the public SSH
  key to your GitLab profile
• Try manually registering your private SSH key using ssh-agent as documented
  earlier in this document
• Try to debug the connection by running ssh -Tv git@example.com
  (replacing example.com with your GitLab domain)

No one wants to send their precious information over unencrypted channels. This is why most websites and web services use HTTPS to encrypt data by default.

When it comes to connecting to GitLab, many users and developers default to using HTTPS. Why? Because everyone knows how a username and password work. Albeit maybe not on a technical level but intuitively it makes sense.

Things tend to get a little more complicated when sending Git commands to a server over HTTPS demands the user submit their username and password in order to perform each action. This can result in quite a lot of prompts. Moreover, when using CI/CD and automation tools, SSH keys are a much better choice for securely authenticating your GitLab account.

In this article, we’ll review what SSH keys are in the context of GitLab authentication, how to create them, and how to keep them safe.

What are SSH Keys?

In order to communicate over SSH (Secure Shell), you must have an SSH key pair. Each SSH key pair has a public and a private key.

Public Key – Can be used to encrypt data in such a way so only the holder of the corresponding private key can decrypt it.

Private Key – Can be used as proof of identity, and is used to authenticate a user’s connection to the server.

When using an SSH key pair as a method of authentication, the public key is stored on the server. It doesn’t really matter if it can be viewed as it is public information. The private key, however, is kept by the user and should not be copied or exposed in any way.

Once this is set up, the server can ask the user for proof of identity using the public key and the user can prove it using the private key.

What are SSH keys in GitLab?

SSH keys are one of the choices for authentication against GitLab servers. The vast majority of actions you will be taking on GitLab via SSH will be pushing changes from your local git repository to the hosted repository on GitLab. 

Although there are other actions you can take, such as starting the GitLab CI/CD pipeline, once started you’re not going to need to interact with the GitLab runner often. Whenever you push code to the hosted repository, it will trigger the pipeline and it will be automated from there, and that action might be scheduled to run many times a day.

Types of SSH keys and options supported

It is generally recommended you use ED25519 SSH keys, which are more secure, and should be available on any system.

However, if you have a good reason to, there are also RSA SSH keys, which would work just as well on GitLab. Although it is recommended you use an SSH key of at least 2048 bits. Do note that by default, a 1024 bit key is generated, so make sure to not use the default.

Why should you use SSH keys in Gitlab?

Aside from the comfort provided by not having to submit your username and password for each action you take, SSH keys are generally much more secure than a username and password. Humans aren’t very good at remembering a large number of secure passwords so they tend to reuse passwords over multiple sites, resulting in many vulnerabilities. No system connected to the internet is truly secure, but with an SSH key you greatly reduce the chance of human error giving away your access privileges.

How to generate an SSH key pair for your GitLab account

The official documentation is fairly comprehensive, but for completeness sake, I will walk you through the process.

One thing you won’t find in the above page, since it shows up in another place in the documentation, is where to type in the commands.

I’m assuming you are using GitBash, as it is the terminal that is supplied with git. For MacOS, Windows PowerShell or Linux terminals instructions, please see the documentation.

How to generate an ED25519 SSH key

To generate ED25519 SSH key you will need to run the following terminal command:

ssh-keygen -t ed25519 -C "<comment>"

The -C and the comment in quotations is optional, but should be used if you’re going to generate more than one pair.

You should see the following response after typing the above command:

Generating public/private ed25519 key pair.
Enter file in which to save the key (/home/user/.ssh/id_ed25519):

How to generate an RSA SSH key pair

If you wish to generate an RSA key pair, use the following command:

ssh-keygen -t rsa -b 2048 -C "email@example.com"

Note the -b 2048, which denotes the number of bits for the key. If you choose to use RSA, the  US National Institute of Science and Technology recommends 2048.

The output should look like this:

Generating public/private rsa key pair.
Enter file in which to save the key (/home/user/.ssh/id_rsa):

Where to save your SSH key pair

Unless you know you need to use a different one, use the default path. But whatever you choose, do not use a network path (more on security later). Your chosen terminal will also use the generated SSH key without further input.

After generating the pair, you will be prompted to optionally add a passphrase:

Enter passphrase (empty for no passphrase):
Enter same passphrase again:

This is optional, but recommended if others may have access to your computer where the key is stored.

How to configure an SSH key in GitLab

The first thing you’ll need is your public ED25519  SSH key in text form, to get this, you can use this command it Git Bash:

cat ~/.ssh/id_ed25519.pub | clip

Or if you’re using RSA:

cat ~/.ssh/id_rsa.pub | clip

Which will copy the SSH key in text form to your clipboard.

While logged into your GitLab account on gitlab.com, follow these steps:

1. Select your avatar and click on settings
2. Click SSH Keys
3. Paste the SSH key into the Key field
4. Add a descriptive text in the title, something that will define you as a user or the computer it is used from
5. Click Add Key

Keeping GitLab SSH keys safe

SSH keys are far less prone to human error, but they are not foolproof. If you’re going to use SSH keys you should have a general idea about the security risks and how to mitigate them. Why? Because not doing so may cost you. In 2019 GoDaddy, one of the largest domain registrars in the world, suffered a critical security breach due to mismanaged SSH keys.

There are many things you could do in order to make your SSH communications more secure, but most of them are done from the server side, not the client side. As an admin, you may want to set up expiration policies, so that new keys need to be generated, and old keys will no longer be valid. This greatly reduces the risk of the keys falling into the wrong hands.

As a user on GitLab though, the main thing you need to concern yourself with is that the private key generated and stored locally should never ever be copied or moved. If you feel your private key may have been compromised, remove the corresponding public key from the server. You might want to do this periodically regardless, to ensure your server’s safety.

If you ever find yourself on a different computer, simply generate a new SSH key pair and upload the public key to GitLab. If a computer is lost, simply delete the public key from your GitLab account and all is well.

Do not backup your SSH keys as the only thing that does is create a vulnerability. As a rule, creating new keys and revoking old ones is a lot less painful than dealing with the fallout of a leaked SSH key pair.