---
stage: Manage
group: Authentication and Authorization
info: To determine the technical writer assigned to the Stage/Group associated with this page, see https://about.gitlab.com/handbook/engineering/ux/technical-writing/#assignments
type: reference
---

# Smartcard authentication **(PREMIUM SELF)**

GitLab supports authentication using smartcards.

## Existing password authentication

> [Introduced](https://gitlab.com/gitlab-org/gitlab/-/issues/33669) in GitLab 12.6.

By default, existing users can continue to log in with a username and password when smartcard
authentication is enabled.

To force existing users to use only smartcard authentication,
[disable username and password authentication](../../user/admin_area/settings/sign_in_restrictions.md#password-authentication-enabled).

## Authentication methods

GitLab supports two authentication methods:

- X.509 certificates with local databases.
- LDAP servers.

### Authentication against a local database with X.509 certificates

> [Introduced](https://gitlab.com/gitlab-org/gitlab/-/issues/726) in GitLab 11.6 as an experimental feature.

WARNING:
Smartcard authentication against local databases may change or be removed completely in future
releases.

Smartcards with X.509 certificates can be used to authenticate with GitLab.

To use a smartcard with an X.509 certificate to authenticate against a local
database with GitLab, `CN` and `emailAddress` must be defined in the
certificate. For example:

```plaintext
Certificate:
    Data:
        Version: 1 (0x0)
        Serial Number: 12856475246677808609 (0xb26b601ecdd555e1)
    Signature Algorithm: sha256WithRSAEncryption
        Issuer: O=Random Corp Ltd, CN=Random Corp
        Validity
            Not Before: Oct 30 12:00:00 2018 GMT
            Not After : Oct 30 12:00:00 2019 GMT
        Subject: CN=Gitlab User, emailAddress=gitlab-user@example.com
```

### Authentication against a local database with X.509 certificates and SAN extension

> [Introduced](https://gitlab.com/gitlab-org/gitlab/-/issues/8605) in GitLab 12.3.

Smartcards with X.509 certificates using SAN extensions can be used to authenticate
with GitLab.

NOTE:
This is an experimental feature. Smartcard authentication against local databases may
change or be removed completely in future releases.

To use a smartcard with an X.509 certificate to authenticate against a local
database with GitLab, in:

- GitLab 12.4 and later, at least one of the `subjectAltName` (SAN) extensions
  need to define the user identity (`email`) within the GitLab instance (`URI`).
  `URI`: needs to match `Gitlab.config.host.gitlab`.
- From [GitLab 12.5](https://gitlab.com/gitlab-org/gitlab/-/issues/33907),
  if your certificate contains only **one** SAN email entry, you don't need to
  add or modify it to match the `email` with the `URI`.

For example:

```plaintext
Certificate:
    Data:
        Version: 1 (0x0)
        Serial Number: 12856475246677808609 (0xb26b601ecdd555e1)
    Signature Algorithm: sha256WithRSAEncryption
        Issuer: O=Random Corp Ltd, CN=Random Corp
        Validity
            Not Before: Oct 30 12:00:00 2018 GMT
            Not After : Oct 30 12:00:00 2019 GMT
        ...
        X509v3 extensions:
            X509v3 Key Usage:
                Key Encipherment, Data Encipherment
            X509v3 Extended Key Usage:
                TLS Web Server Authentication
            X509v3 Subject Alternative Name:
                email:gitlab-user@example.com, URI:http://gitlab.example.com/
```

### Authentication against an LDAP server

> [Introduced](https://gitlab.com/gitlab-org/gitlab/-/issues/7693) in GitLab 11.8 as an experimental feature. Smartcard authentication against an LDAP server may change or be removed completely in the future.

GitLab implements a standard way of certificate matching following
[RFC4523](https://tools.ietf.org/html/rfc4523). It uses the
`certificateExactMatch` certificate matching rule against the `userCertificate`
attribute. As a prerequisite, you must use an LDAP server that:

- Supports the `certificateExactMatch` matching rule.
- Has the certificate stored in the `userCertificate` attribute.

NOTE:
Active Directory doesn't support the `certificateExactMatch` matching rule so
[it is not supported at this time](https://gitlab.com/gitlab-org/gitlab/-/issues/327491). For
more information, see [the relevant issue](https://gitlab.com/gitlab-org/gitlab/-/issues/328074).

## Configure GitLab for smartcard authentication

**For Omnibus installations**

1. Edit `/etc/gitlab/gitlab.rb`:

   ```ruby
   gitlab_rails['smartcard_enabled'] = true
   gitlab_rails['smartcard_ca_file'] = "/etc/ssl/certs/CA.pem"
   gitlab_rails['smartcard_client_certificate_required_host'] = "smartcard.example.com"
   gitlab_rails['smartcard_client_certificate_required_port'] = 3444
   ```

   NOTE:
   Assign a value to at least one of the following variables:
   `gitlab_rails['smartcard_client_certificate_required_host']` or
   `gitlab_rails['smartcard_client_certificate_required_port']`.

1. Save the file and [reconfigure](../restart_gitlab.md#omnibus-gitlab-reconfigure)
   GitLab for the changes to take effect.

---

**For installations from source**

1. Configure NGINX to request a client side certificate

   In NGINX configuration, an **additional** server context must be defined with
   the same configuration except:

   - The additional NGINX server context must be configured to run on a different
     port:

     ```plaintext
     listen *:3444 ssl;
     ```

   - It can also be configured to run on a different hostname:

     ```plaintext
     listen smartcard.example.com:443 ssl;
     ```

   - The additional NGINX server context must be configured to require the client
     side certificate:

     ```plaintext
     ssl_verify_depth 2;
     ssl_client_certificate /etc/ssl/certs/CA.pem;
     ssl_verify_client on;
     ```

   - The additional NGINX server context must be configured to forward the client
     side certificate:

     ```plaintext
     proxy_set_header    X-SSL-Client-Certificate    $ssl_client_escaped_cert;
     ```

   For example, the following is an example server context in an NGINX
   configuration file (such as in `/etc/nginx/sites-available/gitlab-ssl`):

   ```plaintext
   server {
       listen smartcard.example.com:3443 ssl;

       # certificate for configuring SSL
       ssl_certificate /path/to/example.com.crt;
       ssl_certificate_key /path/to/example.com.key;

       ssl_verify_depth 2;
       # CA certificate for client side certificate verification
       ssl_client_certificate /etc/ssl/certs/CA.pem;
       ssl_verify_client on;

       location / {
           proxy_set_header    Host                        $http_host;
           proxy_set_header    X-Real-IP                   $remote_addr;
           proxy_set_header    X-Forwarded-For             $proxy_add_x_forwarded_for;
           proxy_set_header    X-Forwarded-Proto           $scheme;
           proxy_set_header    Upgrade                     $http_upgrade;
           proxy_set_header    Connection                  $connection_upgrade;

           proxy_set_header    X-SSL-Client-Certificate    $ssl_client_escaped_cert;

           proxy_read_timeout 300;

           proxy_pass http://gitlab-workhorse;
       }
   }
   ```

1. Edit `config/gitlab.yml`:

   ```yaml
   ## Smartcard authentication settings
   smartcard:
     # Allow smartcard authentication
     enabled: true

     # Path to a file containing a CA certificate
     ca_file: '/etc/ssl/certs/CA.pem'

     # Host and port where the client side certificate is requested by the
     # webserver (NGINX/Apache)
     client_certificate_required_host: smartcard.example.com
     client_certificate_required_port: 3443
   ```

   NOTE:
   Assign a value to at least one of the following variables:
   `client_certificate_required_host` or `client_certificate_required_port`.

1. Save the file and [restart](../restart_gitlab.md#installations-from-source)
   GitLab for the changes to take effect.

### Additional steps when using SAN extensions

**For Omnibus installations**

1. Add to `/etc/gitlab/gitlab.rb`:

   ```ruby
   gitlab_rails['smartcard_san_extensions'] = true
   ```

1. Save the file and [reconfigure](../restart_gitlab.md#omnibus-gitlab-reconfigure)
   GitLab for the changes to take effect.

**For installations from source**

1. Add the `san_extensions` line to `config/gitlab.yml` within the smartcard section:

   ```yaml
   smartcard:
      enabled: true
      ca_file: '/etc/ssl/certs/CA.pem'
      client_certificate_required_port: 3444

      # Enable the use of SAN extensions to match users with certificates
      san_extensions: true
   ```

1. Save the file and [restart](../restart_gitlab.md#installations-from-source)
   GitLab for the changes to take effect.

### Additional steps when authenticating against an LDAP server

**For Omnibus installations**

1. Edit `/etc/gitlab/gitlab.rb`:

   ```ruby
   gitlab_rails['ldap_servers'] = YAML.load <<-EOS
   main:
     # snip...
     # Enable smartcard authentication against the LDAP server. Valid values
     # are "false", "optional", and "required".
     smartcard_auth: optional
   EOS
   ```

1. Save the file and [reconfigure](../restart_gitlab.md#omnibus-gitlab-reconfigure)
   GitLab for the changes to take effect.

**For installations from source**

1. Edit `config/gitlab.yml`:

   ```yaml
   production:
     ldap:
       servers:
         main:
           # snip...
           # Enable smartcard authentication against the LDAP server. Valid values
           # are "false", "optional", and "required".
           smartcard_auth: optional
   ```

1. Save the file and [restart](../restart_gitlab.md#installations-from-source)
   GitLab for the changes to take effect.

### Require browser session with smartcard sign-in for Git access

**For Omnibus installations**

1. Edit `/etc/gitlab/gitlab.rb`:

   ```ruby
   gitlab_rails['smartcard_required_for_git_access'] = true
   ```

1. Save the file and [reconfigure](../restart_gitlab.md#omnibus-gitlab-reconfigure)
   GitLab for the changes to take effect.

**For installations from source**

1. Edit `config/gitlab.yml`:

   ```yaml
   ## Smartcard authentication settings
   smartcard:
     # snip...
     # Browser session with smartcard sign-in is required for Git access
     required_for_git_access: true
   ```

1. Save the file and [restart](../restart_gitlab.md#installations-from-source)
   GitLab for the changes to take effect.

## Passwords for users created via smartcard authentication

The [Generated passwords for users created through integrated authentication](../../security/passwords_for_integrated_authentication_methods.md) guide provides an overview of how GitLab generates and sets passwords for users created via smartcard authentication.

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