SAML SSO for self-managed GitLab instances

This page describes how to set up instance-wide SAML single sign on (SSO) for self-managed GitLab instances.

You can configure GitLab to act as a SAML service provider (SP). This allows GitLab to consume assertions from a SAML identity provider (IdP), such as Okta, to authenticate users.

To set up SAML on GitLab.com, see SAML SSO for GitLab.com groups.

For more information on:

Configure SAML support in GitLab

Linux package (Omnibus)
  1. Make sure GitLab is configured with HTTPS.
  2. Edit the common configuration file settings to add saml as a single sign-on provider. This enables Just-In-Time account provisioning for users who do not have an existing GitLab account.
  3. To allow your users to use SAML to sign up without having to manually create an account first, edit /etc/gitlab/gitlab.rb:

    gitlab_rails['omniauth_allow_single_sign_on'] = ['saml']
    gitlab_rails['omniauth_block_auto_created_users'] = false
    
  4. Optional. You can automatically link SAML users with existing GitLab users if their email addresses match by adding the following setting in /etc/gitlab/gitlab.rb:

    gitlab_rails['omniauth_auto_link_saml_user'] = true
    

    Alternatively, a user can manually link their SAML identity to an existing GitLab account by enabling OmniAuth for an existing user.

  5. Configure the following attributes so your SAML users cannot change them:

    • NameID.
    • Email when used with omniauth_auto_link_saml_user.

    If users can change these attributes, they can sign in as other authorized users. See your SAML IdP documentation for information on how to make these attributes unchangeable.

  6. Edit /etc/gitlab/gitlab.rb and add the provider configuration:

    gitlab_rails['omniauth_providers'] = [
      {
        name: "saml",
        label: "Provider name", # optional label for login button, defaults to "Saml"
        args: {
          assertion_consumer_service_url: "https://gitlab.example.com/users/auth/saml/callback",
          idp_cert_fingerprint: "43:51:43:a1:b5:fc:8b:b7:0a:3a:a9:b1:0f:66:73:a8",
          idp_sso_target_url: "https://login.example.com/idp",
          issuer: "https://gitlab.example.com",
          name_identifier_format: "urn:oasis:names:tc:SAML:2.0:nameid-format:persistent"
        }
      }
    ]
    

    Where:

    • assertion_consumer_service_url: The GitLab HTTPS endpoint (append /users/auth/saml/callback to the HTTPS URL of your GitLab installation).
    • idp_cert_fingerprint: Your IdP value. It must be a SHA1 fingerprint. For more information on these values, see the OmniAuth SAML documentation. For more information on other configuration settings, see configuring SAML on your IdP.
    • idp_sso_target_url: Your IdP value.
    • issuer: Change to a unique name, which identifies the application to the IdP.
    • name_identifier_format: Your IdP value.
  7. Save the file and reconfigure GitLab:

    sudo gitlab-ctl reconfigure
    
Helm chart (Kubernetes)
  1. Make sure GitLab is configured with HTTPS.
  2. Edit the common configuration file settings to add saml as a single sign-on provider. This enables Just-In-Time account provisioning for users who do not have an existing GitLab account.
  3. Export the Helm values:

    helm get values gitlab > gitlab_values.yaml
    
  4. To allow your users to use SAML to sign up without having to manually create an account first, edit gitlab_values.yaml:

    global:
      appConfig:
        omniauth:
          enabled: true
          allowSingleSignOn: ['saml']
          blockAutoCreatedUsers: true
    
  5. Optional. You can automatically link SAML users with existing GitLab users if their email addresses match by adding the following setting in gitlab_values.yaml:

    global:
      appConfig:
        omniauth:
          autoLinkSamlUser: true
    

    Alternatively, a user can manually link their SAML identity to an existing GitLab account by enabling OmniAuth for an existing user.

  6. Configure the following attributes so your SAML users cannot change them:

    • NameID.
    • Email when used with omniauth_auto_link_saml_user.

    If users can change these attributes, they can sign in as other authorized users. See your SAML IdP documentation for information on how to make these attributes unchangeable.

  7. Put the following content in a file named saml.yaml to be used as a Kubernetes Secret:

    name: 'saml'
    label: 'Provider name' # optional label for login button, defaults to "Saml"
    args:
      assertion_consumer_service_url: 'https://gitlab.example.com/users/auth/saml/callback'
      idp_cert_fingerprint: '43:51:43:a1:b5:fc:8b:b7:0a:3a:a9:b1:0f:66:73:a8'
      idp_sso_target_url: 'https://login.example.com/idp'
      issuer: 'https://gitlab.example.com'
      name_identifier_format: 'urn:oasis:names:tc:SAML:2.0:nameid-format:persistent'
    

    Where:

    • assertion_consumer_service_url: The GitLab HTTPS endpoint (append /users/auth/saml/callback to the HTTPS URL of your GitLab installation).
    • idp_cert_fingerprint: Your IdP value. It must be a SHA1 fingerprint. For more information on these values, see the OmniAuth SAML documentation. For more information on other configuration settings, see configuring SAML on your IdP.
    • idp_sso_target_url: Your IdP value.
    • issuer: Change to a unique name, which identifies the application to the IdP.
    • name_identifier_format: Your IdP value.
  8. Create the Kubernetes Secret:

    kubectl create secret generic -n <namespace> gitlab-saml --from-file=provider=saml.yaml
    
  9. Edit gitlab_values.yaml and add the provider configuration:

    global:
      appConfig:
        omniauth:
          providers:
            - secret: gitlab-saml
    
  10. Save the file and apply the new values:

    helm upgrade -f gitlab_values.yaml gitlab gitlab/gitlab
    
Docker
  1. Make sure GitLab is configured with HTTPS.
  2. Edit the common configuration file settings to add saml as a single sign-on provider. This enables Just-In-Time account provisioning for users who do not have an existing GitLab account.
  3. To allow your users to use SAML to sign up without having to manually create an account first, edit docker-compose.yml:

    version: "3.6"
    services:
      gitlab:
        environment:
          GITLAB_OMNIBUS_CONFIG: |
            gitlab_rails['omniauth_allow_single_sign_on'] = ['saml']
            gitlab_rails['omniauth_block_auto_created_users'] = false
    
  4. Optional. You can automatically link SAML users with existing GitLab users if their email addresses match by adding the following setting in docker-compose.yml:

    version: "3.6"
    services:
      gitlab:
        environment:
          GITLAB_OMNIBUS_CONFIG: |
            gitlab_rails['omniauth_auto_link_saml_user'] = true
    

    Alternatively, a user can manually link their SAML identity to an existing GitLab account by enabling OmniAuth for an existing user.

  5. Configure the following attributes so your SAML users cannot change them:

    • NameID.
    • Email when used with omniauth_auto_link_saml_user.

    If users can change these attributes, they can sign in as other authorized users. See your SAML IdP documentation for information on how to make these attributes unchangeable.

  6. Edit docker-compose.yml and add the provider configuration:

    version: "3.6"
    services:
      gitlab:
        environment:
          GITLAB_OMNIBUS_CONFIG: |
            gitlab_rails['omniauth_providers'] = [
              {
                name: "saml",
                label: "Provider name", # optional label for login button, defaults to "Saml"
                args: {
                  assertion_consumer_service_url: "https://gitlab.example.com/users/auth/saml/callback",
                  idp_cert_fingerprint: "43:51:43:a1:b5:fc:8b:b7:0a:3a:a9:b1:0f:66:73:a8",
                  idp_sso_target_url: "https://login.example.com/idp",
                  issuer: "https://gitlab.example.com",
                  name_identifier_format: "urn:oasis:names:tc:SAML:2.0:nameid-format:persistent"
                }
              }
            ]
    

    Where:

    • assertion_consumer_service_url: The GitLab HTTPS endpoint (append /users/auth/saml/callback to the HTTPS URL of your GitLab installation).
    • idp_cert_fingerprint: Your IdP value. It must be a SHA1 fingerprint. For more information on these values, see the OmniAuth SAML documentation. For more information on other configuration settings, see configuring SAML on your IdP.
    • idp_sso_target_url: Your IdP value.
    • issuer: Change to a unique name, which identifies the application to the IdP.
    • name_identifier_format: Your IdP value.
  7. Save the file and restart GitLab:

    docker compose up -d
    
Self-compiled (source)
  1. Make sure GitLab is configured with HTTPS.
  2. Edit the common configuration file settings to add saml as a single sign-on provider. This enables Just-In-Time account provisioning for users who do not have an existing GitLab account.
  3. To allow your users to use SAML to sign up without having to manually create an account first, edit /home/git/gitlab/config/gitlab.yml:

    production: &base
      omniauth:
        enabled: true
        allow_single_sign_on: ["saml"]
        block_auto_created_users: false
    
  4. Optional. You can automatically link SAML users with existing GitLab users if their email addresses match by adding the following setting in /home/git/gitlab/config/gitlab.yml:

    production: &base
      omniauth:
        auto_link_saml_user: true
    

    Alternatively, a user can manually link their SAML identity to an existing GitLab account by enabling OmniAuth for an existing user.

  5. Configure the following attributes so your SAML users cannot change them:

    • NameID.
    • Email when used with omniauth_auto_link_saml_user.

    If users can change these attributes, they can sign in as other authorized users. See your SAML IdP documentation for information on how to make these attributes unchangeable.

  6. Edit /home/git/gitlab/config/gitlab.yml and add the provider configuration:

    omniauth:
      providers:
        - {
          name: 'saml',
          label: 'Provider name', # optional label for login button, defaults to "Saml"
          args: {
            assertion_consumer_service_url: 'https://gitlab.example.com/users/auth/saml/callback',
            idp_cert_fingerprint: '43:51:43:a1:b5:fc:8b:b7:0a:3a:a9:b1:0f:66:73:a8',
            idp_sso_target_url: 'https://login.example.com/idp',
            issuer: 'https://gitlab.example.com',
            name_identifier_format: 'urn:oasis:names:tc:SAML:2.0:nameid-format:persistent'
          }
        }
    

    Where:

    • assertion_consumer_service_url: The GitLab HTTPS endpoint (append /users/auth/saml/callback to the HTTPS URL of your GitLab installation).
    • idp_cert_fingerprint: Your IdP value. It must be a SHA1 fingerprint. For more information on these values, see the OmniAuth SAML documentation. For more information on other configuration settings, see configuring SAML on your IdP.
    • idp_sso_target_url: Your IdP value.
    • issuer: Change to a unique name, which identifies the application to the IdP.
    • name_identifier_format: Your IdP value.
  7. Save the file and restart GitLab:

    # For systems running systemd
    sudo systemctl restart gitlab.target
    
    # For systems running SysV init
    sudo service gitlab restart
    

Register GitLab in your SAML IdP

  1. Register the GitLab SP in your SAML IdP, using the application name specified in issuer.

  2. To provide configuration information to the IdP, build a metadata URL for the application. To build the metadata URL for GitLab, append users/auth/saml/metadata to the HTTPS URL of your GitLab installation. For example:

    https://gitlab.example.com/users/auth/saml/metadata
    

    At a minimum the IdP must provide a claim containing the user’s email address using email or mail. For more information on other available claims, see configuring assertions.

  3. On the sign in page there should now be a SAML icon below the regular sign in form. Select the icon to begin the authentication process. If authentication is successful, you are returned to GitLab and signed in.

Configure SAML on your IdP

To configure a SAML application on your IdP, you need at least the following information:

For an example configuration, see set up identity providers.

Your IdP may need additional configuration. For more information, see additional configuration for SAML apps on your IdP.

Configure GitLab to use multiple SAML IdPs

Introduced in GitLab 14.6.

You can configure GitLab to use multiple SAML IdPs if:

  • Each provider has a unique name set that matches a name set in args. At least one provider must have the name saml to mitigate a known issue in GitLab 14.6 and newer.
  • The providers’ names are used:
    • In OmniAuth configuration for properties based on the provider name. For example, allowBypassTwoFactor, allowSingleSignOn, and syncProfileFromProvider.
    • For association to each existing user as an additional identity.
  • The assertion_consumer_service_url matches the provider name.
  • The strategy_class is explicitly set because it cannot be inferred from provider name.

SAML group memberships and Group Sync do not support multiple IdPs. For more information, see issue 386605.

To set up multiple SAML IdPs:

Linux package (Omnibus)
  1. Edit /etc/gitlab/gitlab.rb:

    gitlab_rails['omniauth_providers'] = [
      {
        name: 'saml', # This must match the following name configuration parameter
        label: 'Provider 1' # Differentiate the two buttons and providers in the UI
        args: {
                name: 'saml', # This is mandatory and must match the provider name
                assertion_consumer_service_url: 'https://gitlab.example.com/users/auth/saml/callback', # URL must match the name of the provider
                strategy_class: 'OmniAuth::Strategies::SAML',
                ... # Put here all the required arguments similar to a single provider
              },
      },
      {
        name: 'saml_2', # This must match the following name configuration parameter
        label: 'Provider 2' # Differentiate the two buttons and providers in the UI
        args: {
                name: 'saml_2', # This is mandatory and must match the provider name
                assertion_consumer_service_url: 'https://gitlab.example.com/users/auth/saml_2/callback', # URL must match the name of the provider
                strategy_class: 'OmniAuth::Strategies::SAML',
                ... # Put here all the required arguments similar to a single provider
              },
      }
    ]
    

    To allow your users to use SAML to sign up without having to manually create an account from either of the providers, add the following values to your configuration:

    gitlab_rails['omniauth_allow_single_sign_on'] = ['saml', 'saml_2']
    
  2. Save the file and reconfigure GitLab:

    sudo gitlab-ctl reconfigure
    
Helm chart (Kubernetes)
  1. Put the following content in a file named saml.yaml to be used as a Kubernetes Secret for the first SAML provider:

    name: 'saml' # At least one provider must be named 'saml'
    label: 'Provider 1' # Differentiate the two buttons and providers in the UI
    args:
      name: 'saml' # This is mandatory and must match the provider name
      assertion_consumer_service_url: 'https://gitlab.example.com/users/auth/saml/callback' # URL must match the name of the provider
      strategy_class: 'OmniAuth::Strategies::SAML' # Mandatory
      ... # Put here all the required arguments similar to a single provider
    
  2. Put the following content in a file named saml_2.yaml to be used as a Kubernetes Secret for the second SAML provider:

    name: 'saml_2'
    label: 'Provider 2' # Differentiate the two buttons and providers in the UI
    args:
      name: 'saml_2' # This is mandatory and must match the provider name
      assertion_consumer_service_url: 'https://gitlab.example.com/users/auth/saml_2/callback' # URL must match the name of the provider
      strategy_class: 'OmniAuth::Strategies::SAML' # Mandatory
      ... # Put here all the required arguments similar to a single provider
    
  3. Optional. Set additional SAML providers by following the same steps.
  4. Create the Kubernetes Secrets:

    kubectl create secret generic -n <namespace> gitlab-saml \
       --from-file=saml=saml.yaml \
       --from-file=saml_2=saml_2.yaml
    
  5. Export the Helm values:

    helm get values gitlab > gitlab_values.yaml
    
  6. Edit gitlab_values.yaml:

    global:
      appConfig:
        omniauth:
          providers:
            - secret: gitlab-saml
            - key: saml
            - secret: gitlab-saml
            - key: saml_2
    

    To allow your users to use SAML to sign up without having to manually create an account from either of the providers, add the following values to your configuration:

    global:
      appConfig:
        omniauth:
          allowSingleSignOn: ['saml', 'saml_2']
    
  7. Save the file and apply the new values:

    helm upgrade -f gitlab_values.yaml gitlab gitlab/gitlab
    
Docker
  1. Edit docker-compose.yml:

    version: "3.6"
    services:
      gitlab:
        environment:
          GITLAB_OMNIBUS_CONFIG: |
            gitlab_rails['omniauth_allow_single_sign_on'] = ['saml', 'saml1']
            gitlab_rails['omniauth_providers'] = [
              {
                name: 'saml', # This must match the following name configuration parameter
                label: 'Provider 1' # Differentiate the two buttons and providers in the UI
                args: {
                        name: 'saml', # This is mandatory and must match the provider name
                        assertion_consumer_service_url: 'https://gitlab.example.com/users/auth/saml/callback', # URL must match the name of the provider
                        strategy_class: 'OmniAuth::Strategies::SAML',
                        ... # Put here all the required arguments similar to a single provider
                      },
              },
              {
                name: 'saml_2', # This must match the following name configuration parameter
                label: 'Provider 2' # Differentiate the two buttons and providers in the UI
                args: {
                        name: 'saml_2', # This is mandatory and must match the provider name
                        assertion_consumer_service_url: 'https://gitlab.example.com/users/auth/saml_2/callback', # URL must match the name of the provider
                        strategy_class: 'OmniAuth::Strategies::SAML',
                        ... # Put here all the required arguments similar to a single provider
                      },
              }
            ]
    

    To allow your users to use SAML to sign up without having to manually create an account from either of the providers, add the following values to your configuration:

    version: "3.6"
    services:
      gitlab:
        environment:
          GITLAB_OMNIBUS_CONFIG: |
            gitlab_rails['omniauth_allow_single_sign_on'] = ['saml', 'saml_2']
    
  2. Save the file and restart GitLab:

    docker compose up -d
    
Self-compiled (source)
  1. Edit /home/git/gitlab/config/gitlab.yml:

    production: &base
      omniauth:
        providers:
          - {
            name: 'saml', # This must match the following name configuration parameter
            label: 'Provider 1' # Differentiate the two buttons and providers in the UI
            args: {
              name: 'saml', # This is mandatory and must match the provider name
              assertion_consumer_service_url: 'https://gitlab.example.com/users/auth/saml/callback', # URL must match the name of the provider
              strategy_class: 'OmniAuth::Strategies::SAML',
              ... # Put here all the required arguments similar to a single provider
            },
          }
          - {
            name: 'saml_2', # This must match the following name configuration parameter
            label: 'Provider 2' # Differentiate the two buttons and providers in the UI
            args: {
              name: 'saml_2', # This is mandatory and must match the provider name
              strategy_class: 'OmniAuth::Strategies::SAML',
              assertion_consumer_service_url: 'https://gitlab.example.com/users/auth/saml_2/callback', # URL must match the name of the provider
              ... # Put here all the required arguments similar to a single provider
            },
          }
    

    To allow your users to use SAML to sign up without having to manually create an account from either of the providers, add the following values to your configuration:

    production: &base
      omniauth:
        allow_single_sign_on: ["saml", "saml_2"]
    
  2. Save the file and restart GitLab:

    # For systems running systemd
    sudo systemctl restart gitlab.target
    
    # For systems running SysV init
    sudo service gitlab restart
    

Set up identity providers

GitLab support of SAML means you can sign in to GitLab through a wide range of IdPs.

GitLab provides the following content on setting up the Okta and Google Workspace IdPs for guidance only. If you have any questions on configuring either of these IdPs, contact your provider’s support.

Set up Okta

  1. In the Okta administrator section choose Applications.
  2. On the app screen, select Create App Integration and then select SAML 2.0 on the next screen.
  3. Optional. Choose and add a logo from GitLab Press. You must crop and resize the logo.
  4. Complete the SAML general configuration. Enter:
    • "Single sign-on URL": Use the assertion consumer service URL.
    • "Audience URI": Use the issuer.
    • NameID.
    • Assertions.
  5. In the feedback section, enter that you’re a customer and creating an app for internal use.
  6. At the top of your new app’s profile, select SAML 2.0 configuration instructions.
  7. Note the Identity Provider Single Sign-On URL. Use this URL for the idp_sso_target_url on your GitLab configuration file.
  8. Before you sign out of Okta, make sure you add your user and groups if any.

Set up Google Workspace

Prerequisites:

  1. Use the following information, and follow the instructions in Set up your own custom SAML application in Google Workspace.

     Typical valueDescription
    Name of SAML AppGitLabOther names OK.
    ACS URLhttps://<GITLAB_DOMAIN>/users/auth/saml/callbackAssertion Consumer Service URL.
    GITLAB_DOMAINgitlab.example.comYour GitLab instance domain.
    Entity IDhttps://gitlab.example.comA value unique to your SAML application. Set it to the issuer in your GitLab configuration.
    Name ID formatEMAILRequired value. Also known as name_identifier_format.
    Name IDPrimary email addressYour email address. Make sure someone receives content sent to that address.
    First namefirst_nameFirst name. Required value to communicate with GitLab.
    Last namelast_nameLast name. Required value to communicate with GitLab.
  2. Set up the following SAML attribute mappings:

    Google Directory attributesApp attributes
    Basic information > Emailemail
    Basic Information > First namefirst_name
    Basic Information > Last namelast_name

    You might use some of this information when you configure SAML support in GitLab.

When configuring the Google Workspace SAML application, record the following information:

 ValueDescription
SSO URLDependsGoogle Identity Provider details. Set to the GitLab idp_sso_target_url setting.
CertificateDownloadableRun openssl x509 -in <your_certificate.crt> -noout -fingerprint to generate the SHA1 fingerprint that can be used in the idp_cert_fingerprint setting.

Google Workspace Administrator also provides the IdP metadata, Entity ID, and SHA-256 fingerprint. However, GitLab does not need this information to connect to the Google Workspace SAML application.

Set up other IdPs

Some IdPs have documentation on how to use them as the IdP in SAML configurations. For example:

If you have any questions on configuring your IdP in a SAML configuration, contact your provider’s support.

Configure assertions

FieldSupported default keys
Email (required) email, mail
Full Namename
First Name first_name, firstname, firstName
Last Name last_name, lastname, lastName

See attribute_statements for:

  • Custom assertion configuration examples.
  • How to configure custom username attributes.

For a full list of supported assertions, see the OmniAuth SAML gem

Configure users based on SAML group membership

note
SAML Group Sync is only supported for the SAML provider named saml. As a result, SAML Group Sync only supports a single SAML provider. For more information, see issue 366450.

You can:

  • Require users to be members of a certain group.
  • Assign users external, administrator or auditor roles based on group membership.

GitLab checks these groups on each SAML sign in and updates user attributes as necessary. This feature does not allow you to automatically add users to GitLab Groups.

Support for these groups depends on:

GroupTierGitLab Enterprise Edition (EE) Only?
RequiredYes
ExternalNo
AdminYes
AuditorYes

Prerequisites:

  • You must tell GitLab where to look for group information. To do this, make sure that your IdP server sends a specific AttributeStatement along with the regular SAML response. For example:

    <saml:AttributeStatement>
      <saml:Attribute Name="Groups">
        <saml:AttributeValue xsi:type="xs:string">Developers</saml:AttributeValue>
        <saml:AttributeValue xsi:type="xs:string">Freelancers</saml:AttributeValue>
        <saml:AttributeValue xsi:type="xs:string">Admins</saml:AttributeValue>
        <saml:AttributeValue xsi:type="xs:string">Auditors</saml:AttributeValue>
      </saml:Attribute>
    </saml:AttributeStatement>
    

    The name of the attribute must contain the groups that a user belongs to. To tell GitLab where to find these groups, add a groups_attribute: element to your SAML settings.

Required groups

Your IdP passes group information to GitLab in the SAML response. To use this response, configure GitLab to identify:

  • Where to look for the groups in the SAML response, using the groups_attribute setting.
  • Information about a group or user, using a group setting.

Use the required_groups setting to configure GitLab to identify which group membership is required to sign in.

If you do not set required_groups or leave the setting empty, anyone with proper authentication can use the service.

Linux package (Omnibus)
  1. Edit /etc/gitlab/gitlab.rb:

    gitlab_rails['omniauth_providers'] = [
      { name: 'saml',
        label: 'Our SAML Provider',
        groups_attribute: 'Groups',
        required_groups: ['Developers', 'Freelancers', 'Admins', 'Auditors'],
        args: {
                assertion_consumer_service_url: 'https://gitlab.example.com/users/auth/saml/callback',
                idp_cert_fingerprint: '43:51:43:a1:b5:fc:8b:b7:0a:3a:a9:b1:0f:66:73:a8',
                idp_sso_target_url: 'https://login.example.com/idp',
                issuer: 'https://gitlab.example.com',
                name_identifier_format: 'urn:oasis:names:tc:SAML:2.0:nameid-format:persistent'
        }
      }
    ]
    
  2. Save the file and reconfigure GitLab:

    sudo gitlab-ctl reconfigure
    
Helm chart (Kubernetes)
  1. Put the following content in a file named saml.yaml to be used as a Kubernetes Secret:

    name: 'saml'
    label: 'Our SAML Provider'
    groups_attribute: 'Groups'
    required_groups: ['Developers', 'Freelancers', 'Admins', 'Auditors']
    args:
      assertion_consumer_service_url: 'https://gitlab.example.com/users/auth/saml/callback'
      idp_cert_fingerprint: '43:51:43:a1:b5:fc:8b:b7:0a:3a:a9:b1:0f:66:73:a8'
      idp_sso_target_url: 'https://login.example.com/idp'
      issuer: 'https://gitlab.example.com'
      name_identifier_format: 'urn:oasis:names:tc:SAML:2.0:nameid-format:persistent'
    
  2. Create the Kubernetes Secret:

    kubectl create secret generic -n <namespace> gitlab-saml --from-file=provider=saml.yaml
    
  3. Export the Helm values:

    helm get values gitlab > gitlab_values.yaml
    
  4. Edit gitlab_values.yaml:

    global:
      appConfig:
        omniauth:
          providers:
            - secret: gitlab-saml
    
  5. Save the file and apply the new values:

    helm upgrade -f gitlab_values.yaml gitlab gitlab/gitlab
    
Docker
  1. Edit docker-compose.yml:

    version: "3.6"
    services:
      gitlab:
        environment:
          GITLAB_OMNIBUS_CONFIG: |
            gitlab_rails['omniauth_providers'] = [
               { name: 'saml',
                 label: 'Our SAML Provider',
                 groups_attribute: 'Groups',
                 required_groups: ['Developers', 'Freelancers', 'Admins', 'Auditors'],
                 args: {
                         assertion_consumer_service_url: 'https://gitlab.example.com/users/auth/saml/callback',
                         idp_cert_fingerprint: '43:51:43:a1:b5:fc:8b:b7:0a:3a:a9:b1:0f:66:73:a8',
                         idp_sso_target_url: 'https://login.example.com/idp',
                         issuer: 'https://gitlab.example.com',
                         name_identifier_format: 'urn:oasis:names:tc:SAML:2.0:nameid-format:persistent'
                 }
               }
            ]
    
  2. Save the file and restart GitLab:

    docker compose up -d
    
Self-compiled (source)
  1. Edit /home/git/gitlab/config/gitlab.yml:

    production: &base
      omniauth:
        providers:
          - { name: 'saml',
              label: 'Our SAML Provider',
              groups_attribute: 'Groups',
              required_groups: ['Developers', 'Freelancers', 'Admins', 'Auditors'],
              args: {
                      assertion_consumer_service_url: 'https://gitlab.example.com/users/auth/saml/callback',
                      idp_cert_fingerprint: '43:51:43:a1:b5:fc:8b:b7:0a:3a:a9:b1:0f:66:73:a8',
                      idp_sso_target_url: 'https://login.example.com/idp',
                      issuer: 'https://gitlab.example.com',
                      name_identifier_format: 'urn:oasis:names:tc:SAML:2.0:nameid-format:persistent'
              }
            }
    
  2. Save the file and restart GitLab:

    # For systems running systemd
    sudo systemctl restart gitlab.target
    
    # For systems running SysV init
    sudo service gitlab restart
    

External groups

Your IdP passes group information to GitLab in the SAML response. To use this response, configure GitLab to identify:

  • Where to look for the groups in the SAML response, using the groups_attribute setting.
  • Information about a group or user, using a group setting.

SAML can automatically identify a user as an external user, based on the external_groups setting.

Example configuration:

Linux package (Omnibus)
  1. Edit /etc/gitlab/gitlab.rb:

    gitlab_rails['omniauth_providers'] = [
    
      { name: 'saml',
        label: 'Our SAML Provider',
        groups_attribute: 'Groups',
        external_groups: ['Freelancers'],
        args: {
                assertion_consumer_service_url: 'https://gitlab.example.com/users/auth/saml/callback',
                idp_cert_fingerprint: '43:51:43:a1:b5:fc:8b:b7:0a:3a:a9:b1:0f:66:73:a8',
                idp_sso_target_url: 'https://login.example.com/idp',
                issuer: 'https://gitlab.example.com',
                name_identifier_format: 'urn:oasis:names:tc:SAML:2.0:nameid-format:persistent'
        }
      }
    ]
    
  2. Save the file and reconfigure GitLab:

    sudo gitlab-ctl reconfigure
    
Helm chart (Kubernetes)
  1. Put the following content in a file named saml.yaml to be used as a Kubernetes Secret:

    name: 'saml'
    label: 'Our SAML Provider'
    groups_attribute: 'Groups'
    external_groups: ['Freelancers']
    args:
      assertion_consumer_service_url: 'https://gitlab.example.com/users/auth/saml/callback'
      idp_cert_fingerprint: '43:51:43:a1:b5:fc:8b:b7:0a:3a:a9:b1:0f:66:73:a8'
      idp_sso_target_url: 'https://login.example.com/idp'
      issuer: 'https://gitlab.example.com'
      name_identifier_format: 'urn:oasis:names:tc:SAML:2.0:nameid-format:persistent'
    
  2. Create the Kubernetes Secret:

    kubectl create secret generic -n <namespace> gitlab-saml --from-file=provider=saml.yaml
    
  3. Export the Helm values:

    helm get values gitlab > gitlab_values.yaml
    
  4. Edit gitlab_values.yaml:

    global:
      appConfig:
        omniauth:
          providers:
            - secret: gitlab-saml
    
  5. Save the file and apply the new values:

    helm upgrade -f gitlab_values.yaml gitlab gitlab/gitlab
    
Docker
  1. Edit docker-compose.yml:

    version: "3.6"
    services:
      gitlab:
        environment:
          GITLAB_OMNIBUS_CONFIG: |
            gitlab_rails['omniauth_providers'] = [
              { name: 'saml',
                label: 'Our SAML Provider',
                groups_attribute: 'Groups',
                external_groups: ['Freelancers'],
                args: {
                        assertion_consumer_service_url: 'https://gitlab.example.com/users/auth/saml/callback',
                        idp_cert_fingerprint: '43:51:43:a1:b5:fc:8b:b7:0a:3a:a9:b1:0f:66:73:a8',
                        idp_sso_target_url: 'https://login.example.com/idp',
                        issuer: 'https://gitlab.example.com',
                        name_identifier_format: 'urn:oasis:names:tc:SAML:2.0:nameid-format:persistent'
                }
              }
            ]
    
  2. Save the file and restart GitLab:

    docker compose up -d
    
Self-compiled (source)
  1. Edit /home/git/gitlab/config/gitlab.yml:

    production: &base
      omniauth:
        providers:
           - { name: 'saml',
               label: 'Our SAML Provider',
               groups_attribute: 'Groups',
               external_groups: ['Freelancers'],
               args: {
                       assertion_consumer_service_url: 'https://gitlab.example.com/users/auth/saml/callback',
                       idp_cert_fingerprint: '43:51:43:a1:b5:fc:8b:b7:0a:3a:a9:b1:0f:66:73:a8',
                       idp_sso_target_url: 'https://login.example.com/idp',
                       issuer: 'https://gitlab.example.com',
                       name_identifier_format: 'urn:oasis:names:tc:SAML:2.0:nameid-format:persistent'
               }
             }
    
  2. Save the file and restart GitLab:

    # For systems running systemd
    sudo systemctl restart gitlab.target
    
    # For systems running SysV init
    sudo service gitlab restart
    

Administrator groups

Your IdP passes group information to GitLab in the SAML response. To use this response, configure GitLab to identify:

  • Where to look for the groups in the SAML response, using the groups_attribute setting.
  • Information about a group or user, using a group setting.

Use the admin_groups setting to configure GitLab to identify which groups grant the user administrator access.

Example configuration:

Linux package (Omnibus)
  1. Edit /etc/gitlab/gitlab.rb:

    gitlab_rails['omniauth_providers'] = [
      { name: 'saml',
        label: 'Our SAML Provider',
        groups_attribute: 'Groups',
        admin_groups: ['Admins'],
        args: {
                assertion_consumer_service_url: 'https://gitlab.example.com/users/auth/saml/callback',
                idp_cert_fingerprint: '43:51:43:a1:b5:fc:8b:b7:0a:3a:a9:b1:0f:66:73:a8',
                idp_sso_target_url: 'https://login.example.com/idp',
                issuer: 'https://gitlab.example.com',
                name_identifier_format: 'urn:oasis:names:tc:SAML:2.0:nameid-format:persistent'
        }
      }
    ]
    
  2. Save the file and reconfigure GitLab:

    sudo gitlab-ctl reconfigure
    
Helm chart (Kubernetes)
  1. Put the following content in a file named saml.yaml to be used as a Kubernetes Secret:

    name: 'saml'
    label: 'Our SAML Provider'
    groups_attribute: 'Groups'
    admin_groups: ['Admins']
    args:
      assertion_consumer_service_url: 'https://gitlab.example.com/users/auth/saml/callback'
      idp_cert_fingerprint: '43:51:43:a1:b5:fc:8b:b7:0a:3a:a9:b1:0f:66:73:a8'
      idp_sso_target_url: 'https://login.example.com/idp'
      issuer: 'https://gitlab.example.com'
      name_identifier_format: 'urn:oasis:names:tc:SAML:2.0:nameid-format:persistent'
    
  2. Create the Kubernetes Secret:

    kubectl create secret generic -n <namespace> gitlab-saml --from-file=provider=saml.yaml
    
  3. Export the Helm values:

    helm get values gitlab > gitlab_values.yaml
    
  4. Edit gitlab_values.yaml:

    global:
      appConfig:
        omniauth:
          providers:
            - secret: gitlab-saml
    
  5. Save the file and apply the new values:

    helm upgrade -f gitlab_values.yaml gitlab gitlab/gitlab
    
Docker
  1. Edit docker-compose.yml:

    version: "3.6"
    services:
      gitlab:
        environment:
          GITLAB_OMNIBUS_CONFIG: |
            gitlab_rails['omniauth_providers'] = [
               { name: 'saml',
                 label: 'Our SAML Provider',
                 groups_attribute: 'Groups',
                 admin_groups: ['Admins'],
                 args: {
                         assertion_consumer_service_url: 'https://gitlab.example.com/users/auth/saml/callback',
                         idp_cert_fingerprint: '43:51:43:a1:b5:fc:8b:b7:0a:3a:a9:b1:0f:66:73:a8',
                         idp_sso_target_url: 'https://login.example.com/idp',
                         issuer: 'https://gitlab.example.com',
                         name_identifier_format: 'urn:oasis:names:tc:SAML:2.0:nameid-format:persistent'
                 }
               }
            ]
    
  2. Save the file and restart GitLab:

    docker compose up -d
    
Self-compiled (source)
  1. Edit /home/git/gitlab/config/gitlab.yml:

    production: &base
      omniauth:
        providers:
          - { name: 'saml',
              label: 'Our SAML Provider',
              groups_attribute: 'Groups',
              admin_groups: ['Admins'],
              args: {
                      assertion_consumer_service_url: 'https://gitlab.example.com/users/auth/saml/callback',
                      idp_cert_fingerprint: '43:51:43:a1:b5:fc:8b:b7:0a:3a:a9:b1:0f:66:73:a8',
                      idp_sso_target_url: 'https://login.example.com/idp',
                      issuer: 'https://gitlab.example.com',
                      name_identifier_format: 'urn:oasis:names:tc:SAML:2.0:nameid-format:persistent'
              }
            }
    
  2. Save the file and restart GitLab:

    # For systems running systemd
    sudo systemctl restart gitlab.target
    
    # For systems running SysV init
    sudo service gitlab restart
    

Auditor groups

Introduced in GitLab 11.4.

Your IdP passes group information to GitLab in the SAML response. To use this response, configure GitLab to identify:

  • Where to look for the groups in the SAML response, using the groups_attribute setting.
  • Information about a group or user, using a group setting.

Use the auditor_groups setting to configure GitLab to identify which groups include users with auditor access.

Example configuration:

Linux package (Omnibus)
  1. Edit /etc/gitlab/gitlab.rb:

    gitlab_rails['omniauth_providers'] = [
      { name: 'saml',
        label: 'Our SAML Provider',
        groups_attribute: 'Groups',
        auditor_groups: ['Auditors'],
        args: {
                assertion_consumer_service_url: 'https://gitlab.example.com/users/auth/saml/callback',
                idp_cert_fingerprint: '43:51:43:a1:b5:fc:8b:b7:0a:3a:a9:b1:0f:66:73:a8',
                idp_sso_target_url: 'https://login.example.com/idp',
                issuer: 'https://gitlab.example.com',
                name_identifier_format: 'urn:oasis:names:tc:SAML:2.0:nameid-format:persistent'
        }
      }
    ]
    
  2. Save the file and reconfigure GitLab:

    sudo gitlab-ctl reconfigure
    
Helm chart (Kubernetes)
  1. Put the following content in a file named saml.yaml to be used as a Kubernetes Secret:

    name: 'saml'
    label: 'Our SAML Provider'
    groups_attribute: 'Groups'
    auditor_groups: ['Auditors']
    args:
      assertion_consumer_service_url: 'https://gitlab.example.com/users/auth/saml/callback'
      idp_cert_fingerprint: '43:51:43:a1:b5:fc:8b:b7:0a:3a:a9:b1:0f:66:73:a8'
      idp_sso_target_url: 'https://login.example.com/idp'
      issuer: 'https://gitlab.example.com'
      name_identifier_format: 'urn:oasis:names:tc:SAML:2.0:nameid-format:persistent'
    
  2. Create the Kubernetes Secret:

    kubectl create secret generic -n <namespace> gitlab-saml --from-file=provider=saml.yaml
    
  3. Export the Helm values:

    helm get values gitlab > gitlab_values.yaml
    
  4. Edit gitlab_values.yaml:

    global:
      appConfig:
        omniauth:
          providers:
            - secret: gitlab-saml
    
  5. Save the file and apply the new values:

    helm upgrade -f gitlab_values.yaml gitlab gitlab/gitlab
    
Docker
  1. Edit docker-compose.yml:

    version: "3.6"
    services:
      gitlab:
        environment:
          GITLAB_OMNIBUS_CONFIG: |
            gitlab_rails['omniauth_providers'] = [
               { name: 'saml',
                 label: 'Our SAML Provider',
                 groups_attribute: 'Groups',
                 auditor_groups: ['Auditors'],
                 args: {
                         assertion_consumer_service_url: 'https://gitlab.example.com/users/auth/saml/callback',
                         idp_cert_fingerprint: '43:51:43:a1:b5:fc:8b:b7:0a:3a:a9:b1:0f:66:73:a8',
                         idp_sso_target_url: 'https://login.example.com/idp',
                         issuer: 'https://gitlab.example.com',
                         name_identifier_format: 'urn:oasis:names:tc:SAML:2.0:nameid-format:persistent'
                 }
               }
            ]
    
  2. Save the file and restart GitLab:

    docker compose up -d
    
Self-compiled (source)
  1. Edit /home/git/gitlab/config/gitlab.yml:

    production: &base
      omniauth:
        providers:
          - { name: 'saml',
              label: 'Our SAML Provider',
              groups_attribute: 'Groups',
              auditor_groups: ['Auditors'],
              args: {
                      assertion_consumer_service_url: 'https://gitlab.example.com/users/auth/saml/callback',
                      idp_cert_fingerprint: '43:51:43:a1:b5:fc:8b:b7:0a:3a:a9:b1:0f:66:73:a8',
                      idp_sso_target_url: 'https://login.example.com/idp',
                      issuer: 'https://gitlab.example.com',
                      name_identifier_format: 'urn:oasis:names:tc:SAML:2.0:nameid-format:persistent'
              }
            }
    
  2. Save the file and restart GitLab:

    # For systems running systemd
    sudo systemctl restart gitlab.target
    
    # For systems running SysV init
    sudo service gitlab restart
    

Automatically manage SAML Group Sync

For information on automatically managing GitLab group membership, see SAML Group Sync.

Bypass two-factor authentication

To configure a SAML authentication method to count as two-factor authentication (2FA) on a per session basis, register that method in the upstream_two_factor_authn_contexts list.

  1. Make sure that your IdP is returning the AuthnContext. For example:

    <saml:AuthnStatement>
        <saml:AuthnContext>
            <saml:AuthnContextClassRef>urn:oasis:names:tc:SAML:2.0:ac:classes:MediumStrongCertificateProtectedTransport</saml:AuthnContextClassRef>
        </saml:AuthnContext>
    </saml:AuthnStatement>
    
  2. Edit your installation configuration to register the SAML authentication method in the upstream_two_factor_authn_contexts list.

    Linux package (Omnibus)
    1. Edit /etc/gitlab/gitlab.rb:

      gitlab_rails['omniauth_providers'] = [
        { name: 'saml',
          label: 'Our SAML Provider',
          args: {
                  assertion_consumer_service_url: 'https://gitlab.example.com/users/auth/saml/callback',
                  idp_cert_fingerprint: '43:51:43:a1:b5:fc:8b:b7:0a:3a:a9:b1:0f:66:73:a8',
                  idp_sso_target_url: 'https://login.example.com/idp',
                  issuer: 'https://gitlab.example.com',
                  name_identifier_format: 'urn:oasis:names:tc:SAML:2.0:nameid-format:persistent'
                  upstream_two_factor_authn_contexts:
                    %w(
                      urn:oasis:names:tc:SAML:2.0:ac:classes:CertificateProtectedTransport
                      urn:oasis:names:tc:SAML:2.0:ac:classes:SecondFactorOTPSMS
                      urn:oasis:names:tc:SAML:2.0:ac:classes:SecondFactorIGTOKEN
                    ),
          }
        }
      ]
      
    2. Save the file and reconfigure GitLab:

      sudo gitlab-ctl reconfigure
      
    Helm chart (Kubernetes)
    1. Put the following content in a file named saml.yaml to be used as a Kubernetes Secret:

      name: 'saml'
      label: 'Our SAML Provider'
      args:
        assertion_consumer_service_url: 'https://gitlab.example.com/users/auth/saml/callback'
        idp_cert_fingerprint: '43:51:43:a1:b5:fc:8b:b7:0a:3a:a9:b1:0f:66:73:a8'
        idp_sso_target_url: 'https://login.example.com/idp'
        issuer: 'https://gitlab.example.com'
        name_identifier_format: 'urn:oasis:names:tc:SAML:2.0:nameid-format:persistent'
        upstream_two_factor_authn_contexts:
          - 'urn:oasis:names:tc:SAML:2.0:ac:classes:CertificateProtectedTransport'
          - 'urn:oasis:names:tc:SAML:2.0:ac:classes:SecondFactorOTPSMS'
          - 'urn:oasis:names:tc:SAML:2.0:ac:classes:SecondFactorIGTOKEN'
      
    2. Create the Kubernetes Secret:

      kubectl create secret generic -n <namespace> gitlab-saml --from-file=provider=saml.yaml
      
    3. Export the Helm values:

      helm get values gitlab > gitlab_values.yaml
      
    4. Edit gitlab_values.yaml:

      global:
        appConfig:
          omniauth:
            providers:
              - secret: gitlab-saml
      
    5. Save the file and apply the new values:

      helm upgrade -f gitlab_values.yaml gitlab gitlab/gitlab
      
    Docker
    1. Edit docker-compose.yml:

      version: "3.6"
      services:
        gitlab:
          environment:
            GITLAB_OMNIBUS_CONFIG: |
              gitlab_rails['omniauth_providers'] = [
                 { name: 'saml',
                   label: 'Our SAML Provider',
                   args: {
                           assertion_consumer_service_url: 'https://gitlab.example.com/users/auth/saml/callback',
                           idp_cert_fingerprint: '43:51:43:a1:b5:fc:8b:b7:0a:3a:a9:b1:0f:66:73:a8',
                           idp_sso_target_url: 'https://login.example.com/idp',
                           issuer: 'https://gitlab.example.com',
                           name_identifier_format: 'urn:oasis:names:tc:SAML:2.0:nameid-format:persistent'
                           upstream_two_factor_authn_contexts:
                             %w(
                               urn:oasis:names:tc:SAML:2.0:ac:classes:CertificateProtectedTransport
                               urn:oasis:names:tc:SAML:2.0:ac:classes:SecondFactorOTPSMS
                               urn:oasis:names:tc:SAML:2.0:ac:classes:SecondFactorIGTOKEN
                             )
                   }
                 }
              ]
      
    2. Save the file and restart GitLab:

      docker compose up -d
      
    Self-compiled (source)
    1. Edit /home/git/gitlab/config/gitlab.yml:

      production: &base
        omniauth:
          providers:
            - { name: 'saml',
                label: 'Our SAML Provider',
                args: {
                        assertion_consumer_service_url: 'https://gitlab.example.com/users/auth/saml/callback',
                        idp_cert_fingerprint: '43:51:43:a1:b5:fc:8b:b7:0a:3a:a9:b1:0f:66:73:a8',
                        idp_sso_target_url: 'https://login.example.com/idp',
                        issuer: 'https://gitlab.example.com',
                        name_identifier_format: 'urn:oasis:names:tc:SAML:2.0:nameid-format:persistent'
                        upstream_two_factor_authn_contexts:
                          [
                            'urn:oasis:names:tc:SAML:2.0:ac:classes:CertificateProtectedTransport',
                            'urn:oasis:names:tc:SAML:2.0:ac:classes:SecondFactorOTPSMS',
                            'urn:oasis:names:tc:SAML:2.0:ac:classes:SecondFactorIGTOKEN'
                          ]
                }
              }
      
    2. Save the file and restart GitLab:

      # For systems running systemd
      sudo systemctl restart gitlab.target
      
      # For systems running SysV init
      sudo service gitlab restart
      

Validate response signatures

IdPs must sign SAML responses to ensure that the assertions are not tampered with.

This prevents user impersonation and privilege escalation when specific group membership is required.

Using idp_cert_fingerprint

You configure the response signature validation using idp_cert_fingerprint. An example configuration:

Linux package (Omnibus)
  1. Edit /etc/gitlab/gitlab.rb:

    gitlab_rails['omniauth_providers'] = [
      { name: 'saml',
        label: 'Our SAML Provider',
        args: {
                assertion_consumer_service_url: 'https://gitlab.example.com/users/auth/saml/callback',
                idp_cert_fingerprint: '43:51:43:a1:b5:fc:8b:b7:0a:3a:a9:b1:0f:66:73:a8',
                idp_sso_target_url: 'https://login.example.com/idp',
                issuer: 'https://gitlab.example.com',
                name_identifier_format: 'urn:oasis:names:tc:SAML:2.0:nameid-format:persistent'
        }
      }
    ]
    
  2. Save the file and reconfigure GitLab:

    sudo gitlab-ctl reconfigure
    
Helm chart (Kubernetes)
  1. Put the following content in a file named saml.yaml to be used as a Kubernetes Secret:

    name: 'saml'
    label: 'Our SAML Provider'
    args:
      assertion_consumer_service_url: 'https://gitlab.example.com/users/auth/saml/callback'
      idp_cert_fingerprint: '43:51:43:a1:b5:fc:8b:b7:0a:3a:a9:b1:0f:66:73:a8'
      idp_sso_target_url: 'https://login.example.com/idp'
      issuer: 'https://gitlab.example.com'
      name_identifier_format: 'urn:oasis:names:tc:SAML:2.0:nameid-format:persistent'
    
  2. Create the Kubernetes Secret:

    kubectl create secret generic -n <namespace> gitlab-saml --from-file=provider=saml.yaml
    
  3. Export the Helm values:

    helm get values gitlab > gitlab_values.yaml
    
  4. Edit gitlab_values.yaml:

    global:
      appConfig:
        omniauth:
          providers:
            - secret: gitlab-saml
    
  5. Save the file and apply the new values:

    helm upgrade -f gitlab_values.yaml gitlab gitlab/gitlab
    
Docker
  1. Edit docker-compose.yml:

    version: "3.6"
    services:
      gitlab:
        environment:
          GITLAB_OMNIBUS_CONFIG: |
            gitlab_rails['omniauth_providers'] = [
               { name: 'saml',
                 label: 'Our SAML Provider',
                 args: {
                         assertion_consumer_service_url: 'https://gitlab.example.com/users/auth/saml/callback',
                         idp_cert_fingerprint: '43:51:43:a1:b5:fc:8b:b7:0a:3a:a9:b1:0f:66:73:a8',
                         idp_sso_target_url: 'https://login.example.com/idp',
                         issuer: 'https://gitlab.example.com',
                         name_identifier_format: 'urn:oasis:names:tc:SAML:2.0:nameid-format:persistent'
                 }
               }
            ]
    
  2. Save the file and restart GitLab:

    docker compose up -d
    
Self-compiled (source)
  1. Edit /home/git/gitlab/config/gitlab.yml:

    production: &base
      omniauth:
        providers:
          - { name: 'saml',
              label: 'Our SAML Provider',
              args: {
                      assertion_consumer_service_url: 'https://gitlab.example.com/users/auth/saml/callback',
                      idp_cert_fingerprint: '43:51:43:a1:b5:fc:8b:b7:0a:3a:a9:b1:0f:66:73:a8',
                      idp_sso_target_url: 'https://login.example.com/idp',
                      issuer: 'https://gitlab.example.com',
                      name_identifier_format: 'urn:oasis:names:tc:SAML:2.0:nameid-format:persistent'
              }
            }
    
  2. Save the file and restart GitLab:

    # For systems running systemd
    sudo systemctl restart gitlab.target
    
    # For systems running SysV init
    sudo service gitlab restart
    

Using idp_cert

If your IdP does not support configuring this using idp_cert_fingerprint, you can instead configure GitLab directly using idp_cert. An example configuration:

Linux package (Omnibus)
  1. Edit /etc/gitlab/gitlab.rb:

    gitlab_rails['omniauth_providers'] = [
      { name: 'saml',
        label: 'Our SAML Provider',
        args: {
                assertion_consumer_service_url: 'https://gitlab.example.com/users/auth/saml/callback',
                idp_cert: '-----BEGIN CERTIFICATE-----
                  <redacted>
                  -----END CERTIFICATE-----',
                idp_sso_target_url: 'https://login.example.com/idp',
                issuer: 'https://gitlab.example.com',
                name_identifier_format: 'urn:oasis:names:tc:SAML:2.0:nameid-format:persistent'
        }
      }
    ]
    
  2. Save the file and reconfigure GitLab:

    sudo gitlab-ctl reconfigure
    
Helm chart (Kubernetes)
  1. Put the following content in a file named saml.yaml to be used as a Kubernetes Secret:

    name: 'saml'
    label: 'Our SAML Provider'
    args:
      assertion_consumer_service_url: 'https://gitlab.example.com/users/auth/saml/callback'
      idp_cert: |
        -----BEGIN CERTIFICATE-----
        <redacted>
        -----END CERTIFICATE-----
      idp_sso_target_url: 'https://login.example.com/idp'
      issuer: 'https://gitlab.example.com'
      name_identifier_format: 'urn:oasis:names:tc:SAML:2.0:nameid-format:persistent'
    
  2. Create the Kubernetes Secret:

    kubectl create secret generic -n <namespace> gitlab-saml --from-file=provider=saml.yaml
    
  3. Export the Helm values:

    helm get values gitlab > gitlab_values.yaml
    
  4. Edit gitlab_values.yaml:

    global:
      appConfig:
        omniauth:
          providers:
            - secret: gitlab-saml
    
  5. Save the file and apply the new values:

    helm upgrade -f gitlab_values.yaml gitlab gitlab/gitlab
    
Docker
  1. Edit docker-compose.yml:

    version: "3.6"
    services:
      gitlab:
        environment:
          GITLAB_OMNIBUS_CONFIG: |
            gitlab_rails['omniauth_providers'] = [
               { name: 'saml',
                 label: 'Our SAML Provider',
                 args: {
                         assertion_consumer_service_url: 'https://gitlab.example.com/users/auth/saml/callback',
                         idp_cert: '-----BEGIN CERTIFICATE-----
                           <redacted>
                           -----END CERTIFICATE-----',
                         idp_sso_target_url: 'https://login.example.com/idp',
                         issuer: 'https://gitlab.example.com',
                         name_identifier_format: 'urn:oasis:names:tc:SAML:2.0:nameid-format:persistent'
                 }
               }
            ]
    
  2. Save the file and restart GitLab:

    docker compose up -d
    
Self-compiled (source)
  1. Edit /home/git/gitlab/config/gitlab.yml:

    production: &base
      omniauth:
        providers:
          - { name: 'saml',
              label: 'Our SAML Provider',
              args: {
                      assertion_consumer_service_url: 'https://gitlab.example.com/users/auth/saml/callback',
                      idp_cert: '-----BEGIN CERTIFICATE-----
                        <redacted>
                        -----END CERTIFICATE-----',
                      idp_sso_target_url: 'https://login.example.com/idp',
                      issuer: 'https://gitlab.example.com',
                      name_identifier_format: 'urn:oasis:names:tc:SAML:2.0:nameid-format:persistent'
              }
            }
    
  2. Save the file and restart GitLab:

    # For systems running systemd
    sudo systemctl restart gitlab.target
    
    # For systems running SysV init
    sudo service gitlab restart
    

If you have configured the response signature validation incorrectly, you might see error messages such as:

  • A key validation error.
  • Digest mismatch.
  • Fingerprint mismatch.

For more information on solving these errors, see the troubleshooting SAML guide.

Customize SAML settings

Redirect users to SAML server for authentication

You can add the auto_sign_in_with_provider setting to your GitLab configuration to automatically redirect you to your SAML server for authentication. This removes the requirement to select an element before actually signing in.

Linux package (Omnibus)
  1. Edit /etc/gitlab/gitlab.rb:

    gitlab_rails['omniauth_auto_sign_in_with_provider'] = 'saml'
    
  2. Save the file and reconfigure GitLab:

    sudo gitlab-ctl reconfigure
    
Helm chart (Kubernetes)
  1. Export the Helm values:

    helm get values gitlab > gitlab_values.yaml
    
  2. Edit gitlab_values.yaml:

    global:
      appConfig:
        omniauth:
          autoSignInWithProvider: 'saml'
    
  3. Save the file and apply the new values:

    helm upgrade -f gitlab_values.yaml gitlab gitlab/gitlab
    
Docker
  1. Edit docker-compose.yml:

    version: "3.6"
    services:
      gitlab:
        environment:
          GITLAB_OMNIBUS_CONFIG: |
            gitlab_rails['omniauth_auto_sign_in_with_provider'] = 'saml'
    
  2. Save the file and restart GitLab:

    docker compose up -d
    
Self-compiled (source)
  1. Edit /home/git/gitlab/config/gitlab.yml:

    production: &base
      omniauth:
        auto_sign_in_with_provider: 'saml'
    
  2. Save the file and restart GitLab:

    # For systems running systemd
    sudo systemctl restart gitlab.target
    
    # For systems running SysV init
    sudo service gitlab restart
    

Every sign in attempt redirects to the SAML server, so you cannot sign in using local credentials. Make sure at least one of the SAML users has administrator access.

note
To bypass the auto sign-in setting, append ?auto_sign_in=false in the sign in URL, for example: https://gitlab.example.com/users/sign_in?auto_sign_in=false.

Map SAML response attribute names

You can use attribute_statements to map attribute names in a SAML response to entries in the OmniAuth info hash.

note
Only use this setting to map attributes that are part of the OmniAuth info hash schema.

For example, if your SAMLResponse contains an Attribute called EmailAddress, specify { email: ['EmailAddress'] } to map the Attribute to the corresponding key in the info hash. URI-named Attributes are also supported, for example, { email: ['http://schemas.xmlsoap.org/ws/2005/05/identity/claims/emailaddress'] }.

Use this setting to tell GitLab where to look for certain attributes required to create an account. For example, if your IdP sends the user’s email address as EmailAddress instead of email, let GitLab know by setting it on your configuration:

Linux package (Omnibus)
  1. Edit /etc/gitlab/gitlab.rb:

    gitlab_rails['omniauth_providers'] = [
      { name: 'saml',
        label: 'Our SAML Provider',
        args: {
                assertion_consumer_service_url: 'https://gitlab.example.com/users/auth/saml/callback',
                idp_cert_fingerprint: '43:51:43:a1:b5:fc:8b:b7:0a:3a:a9:b1:0f:66:73:a8',
                idp_sso_target_url: 'https://login.example.com/idp',
                issuer: 'https://gitlab.example.com',
                name_identifier_format: 'urn:oasis:names:tc:SAML:2.0:nameid-format:persistent',
                attribute_statements: { email: ['EmailAddress'] }
        }
      }
    ]
    
  2. Save the file and reconfigure GitLab:

    sudo gitlab-ctl reconfigure
    
Helm chart (Kubernetes)
  1. Put the following content in a file named saml.yaml to be used as a Kubernetes Secret:

    name: 'saml'
    label: 'Our SAML Provider'
    args:
      assertion_consumer_service_url: 'https://gitlab.example.com/users/auth/saml/callback'
      idp_cert_fingerprint: '43:51:43:a1:b5:fc:8b:b7:0a:3a:a9:b1:0f:66:73:a8'
      idp_sso_target_url: 'https://login.example.com/idp'
      issuer: 'https://gitlab.example.com'
      name_identifier_format: 'urn:oasis:names:tc:SAML:2.0:nameid-format:persistent'
      attribute_statements:
        email: ['EmailAddress']
    
  2. Create the Kubernetes Secret:

    kubectl create secret generic -n <namespace> gitlab-saml --from-file=provider=saml.yaml
    
  3. Export the Helm values:

    helm get values gitlab > gitlab_values.yaml
    
  4. Edit gitlab_values.yaml:

    global:
      appConfig:
        omniauth:
          providers:
            - secret: gitlab-saml
    
  5. Save the file and apply the new values:

    helm upgrade -f gitlab_values.yaml gitlab gitlab/gitlab
    
Docker
  1. Edit docker-compose.yml:

    version: "3.6"
    services:
      gitlab:
        environment:
          GITLAB_OMNIBUS_CONFIG: |
            gitlab_rails['omniauth_providers'] = [
               { name: 'saml',
                 label: 'Our SAML Provider',
                 args: {
                         assertion_consumer_service_url: 'https://gitlab.example.com/users/auth/saml/callback',
                         idp_cert_fingerprint: '43:51:43:a1:b5:fc:8b:b7:0a:3a:a9:b1:0f:66:73:a8',
                         idp_sso_target_url: 'https://login.example.com/idp',
                         issuer: 'https://gitlab.example.com',
                         name_identifier_format: 'urn:oasis:names:tc:SAML:2.0:nameid-format:persistent',
                         attribute_statements: { email: ['EmailAddress'] }
                 }
               }
            ]
    
  2. Save the file and restart GitLab:

    docker compose up -d
    
Self-compiled (source)
  1. Edit /home/git/gitlab/config/gitlab.yml:

    production: &base
      omniauth:
        providers:
          - { name: 'saml',
              label: 'Our SAML Provider',
              args: {
                      assertion_consumer_service_url: 'https://gitlab.example.com/users/auth/saml/callback',
                      idp_cert_fingerprint: '43:51:43:a1:b5:fc:8b:b7:0a:3a:a9:b1:0f:66:73:a8',
                      idp_sso_target_url: 'https://login.example.com/idp',
                      issuer: 'https://gitlab.example.com',
                      name_identifier_format: 'urn:oasis:names:tc:SAML:2.0:nameid-format:persistent',
                      attribute_statements: { email: ['EmailAddress'] }
              }
            }
    
  2. Save the file and restart GitLab:

    # For systems running systemd
    sudo systemctl restart gitlab.target
    
    # For systems running SysV init
    sudo service gitlab restart
    

Set a username

By default, the local part of the email address in the SAML response is used to generate the user’s GitLab username.

Configure nickname in attribute_statements to specify one or more attributes that contain a user’s desired username:

Linux package (Omnibus)
  1. Edit /etc/gitlab/gitlab.rb:

    gitlab_rails['omniauth_providers'] = [
      { name: 'saml',
        label: 'Our SAML Provider',
        args: {
                assertion_consumer_service_url: 'https://gitlab.example.com/users/auth/saml/callback',
                idp_cert_fingerprint: '43:51:43:a1:b5:fc:8b:b7:0a:3a:a9:b1:0f:66:73:a8',
                idp_sso_target_url: 'https://login.example.com/idp',
                issuer: 'https://gitlab.example.com',
                name_identifier_format: 'urn:oasis:names:tc:SAML:2.0:nameid-format:persistent',
                attribute_statements: { nickname: ['username'] }
        }
      }
    ]
    
  2. Save the file and reconfigure GitLab:

    sudo gitlab-ctl reconfigure
    
Helm chart (Kubernetes)
  1. Put the following content in a file named saml.yaml to be used as a Kubernetes Secret:

    name: 'saml'
    label: 'Our SAML Provider'
    args:
      assertion_consumer_service_url: 'https://gitlab.example.com/users/auth/saml/callback'
      idp_cert_fingerprint: '43:51:43:a1:b5:fc:8b:b7:0a:3a:a9:b1:0f:66:73:a8'
      idp_sso_target_url: 'https://login.example.com/idp'
      issuer: 'https://gitlab.example.com'
      name_identifier_format: 'urn:oasis:names:tc:SAML:2.0:nameid-format:persistent'
      attribute_statements:
        nickname: ['username']
    
  2. Create the Kubernetes Secret:

    kubectl create secret generic -n <namespace> gitlab-saml --from-file=provider=saml.yaml
    
  3. Export the Helm values:

    helm get values gitlab > gitlab_values.yaml
    
  4. Edit gitlab_values.yaml:

    global:
      appConfig:
        omniauth:
          providers:
            - secret: gitlab-saml
    
  5. Save the file and apply the new values:

    helm upgrade -f gitlab_values.yaml gitlab gitlab/gitlab
    
Docker
  1. Edit docker-compose.yml:

    version: "3.6"
    services:
      gitlab:
        environment:
          GITLAB_OMNIBUS_CONFIG: |
            gitlab_rails['omniauth_providers'] = [
               { name: 'saml',
                 label: 'Our SAML Provider',
                 groups_attribute: 'Groups',
                 required_groups: ['Developers', 'Freelancers', 'Admins', 'Auditors'],
                 args: {
                         assertion_consumer_service_url: 'https://gitlab.example.com/users/auth/saml/callback',
                         idp_cert_fingerprint: '43:51:43:a1:b5:fc:8b:b7:0a:3a:a9:b1:0f:66:73:a8',
                         idp_sso_target_url: 'https://login.example.com/idp',
                         issuer: 'https://gitlab.example.com',
                         name_identifier_format: 'urn:oasis:names:tc:SAML:2.0:nameid-format:persistent',
                         attribute_statements: { nickname: ['username'] }
                 }
               }
            ]
    
  2. Save the file and restart GitLab:

    docker compose up -d
    
Self-compiled (source)
  1. Edit /home/git/gitlab/config/gitlab.yml:

    production: &base
      omniauth:
        providers:
          - { name: 'saml',
              label: 'Our SAML Provider',
              groups_attribute: 'Groups',
              required_groups: ['Developers', 'Freelancers', 'Admins', 'Auditors'],
              args: {
                      assertion_consumer_service_url: 'https://gitlab.example.com/users/auth/saml/callback',
                      idp_cert_fingerprint: '43:51:43:a1:b5:fc:8b:b7:0a:3a:a9:b1:0f:66:73:a8',
                      idp_sso_target_url: 'https://login.example.com/idp',
                      issuer: 'https://gitlab.example.com',
                      name_identifier_format: 'urn:oasis:names:tc:SAML:2.0:nameid-format:persistent',
                      attribute_statements: { nickname: ['username'] }
              }
            }
    
  2. Save the file and restart GitLab:

    # For systems running systemd
    sudo systemctl restart gitlab.target
    
    # For systems running SysV init
    sudo service gitlab restart
    

This also sets the username attribute in your SAML Response to the username in GitLab.

Allow for clock drift

The clock of the IdP may drift slightly ahead of your system clocks. To allow for a small amount of clock drift, use allowed_clock_drift in your settings. You must enter the parameter’s value in a number and fraction of seconds. The value given is added to the current time at which the response is validated.

Linux package (Omnibus)
  1. Edit /etc/gitlab/gitlab.rb:

    gitlab_rails['omniauth_providers'] = [
      { name: 'saml',
        label: 'Our SAML Provider',
        groups_attribute: 'Groups',
        required_groups: ['Developers', 'Freelancers', 'Admins', 'Auditors'],
        args: {
                assertion_consumer_service_url: 'https://gitlab.example.com/users/auth/saml/callback',
                idp_cert_fingerprint: '43:51:43:a1:b5:fc:8b:b7:0a:3a:a9:b1:0f:66:73:a8',
                idp_sso_target_url: 'https://login.example.com/idp',
                issuer: 'https://gitlab.example.com',
                name_identifier_format: 'urn:oasis:names:tc:SAML:2.0:nameid-format:persistent',
                allowed_clock_drift: 1  # for one second clock drift
        }
      }
    ]
    
  2. Save the file and reconfigure GitLab:

    sudo gitlab-ctl reconfigure
    
Helm chart (Kubernetes)
  1. Put the following content in a file named saml.yaml to be used as a Kubernetes Secret:

    name: 'saml'
    label: 'Our SAML Provider'
    groups_attribute: 'Groups'
    required_groups: ['Developers', 'Freelancers', 'Admins', 'Auditors']
    args:
      assertion_consumer_service_url: 'https://gitlab.example.com/users/auth/saml/callback'
      idp_cert_fingerprint: '43:51:43:a1:b5:fc:8b:b7:0a:3a:a9:b1:0f:66:73:a8'
      idp_sso_target_url: 'https://login.example.com/idp'
      issuer: 'https://gitlab.example.com'
      name_identifier_format: 'urn:oasis:names:tc:SAML:2.0:nameid-format:persistent'
      allowed_clock_drift: 1  # for one second clock drift
    
  2. Create the Kubernetes Secret:

    kubectl create secret generic -n <namespace> gitlab-saml --from-file=provider=saml.yaml
    
  3. Export the Helm values:

    helm get values gitlab > gitlab_values.yaml
    
  4. Edit gitlab_values.yaml:

    global:
      appConfig:
        omniauth:
          providers:
            - secret: gitlab-saml
    
  5. Save the file and apply the new values:

    helm upgrade -f gitlab_values.yaml gitlab gitlab/gitlab
    
Docker
  1. Edit docker-compose.yml:

    version: "3.6"
    services:
      gitlab:
        environment:
          GITLAB_OMNIBUS_CONFIG: |
            gitlab_rails['omniauth_providers'] = [
               { name: 'saml',
                 label: 'Our SAML Provider',
                 groups_attribute: 'Groups',
                 required_groups: ['Developers', 'Freelancers', 'Admins', 'Auditors'],
                 args: {
                         assertion_consumer_service_url: 'https://gitlab.example.com/users/auth/saml/callback',
                         idp_cert_fingerprint: '43:51:43:a1:b5:fc:8b:b7:0a:3a:a9:b1:0f:66:73:a8',
                         idp_sso_target_url: 'https://login.example.com/idp',
                         issuer: 'https://gitlab.example.com',
                         name_identifier_format: 'urn:oasis:names:tc:SAML:2.0:nameid-format:persistent',
                         allowed_clock_drift: 1  # for one second clock drift
                 }
               }
            ]
    
  2. Save the file and restart GitLab:

    docker compose up -d
    
Self-compiled (source)
  1. Edit /home/git/gitlab/config/gitlab.yml:

    production: &base
      omniauth:
        providers:
          - { name: 'saml',
              label: 'Our SAML Provider',
              groups_attribute: 'Groups',
              required_groups: ['Developers', 'Freelancers', 'Admins', 'Auditors'],
              args: {
                      assertion_consumer_service_url: 'https://gitlab.example.com/users/auth/saml/callback',
                      idp_cert_fingerprint: '43:51:43:a1:b5:fc:8b:b7:0a:3a:a9:b1:0f:66:73:a8',
                      idp_sso_target_url: 'https://login.example.com/idp',
                      issuer: 'https://gitlab.example.com',
                      name_identifier_format: 'urn:oasis:names:tc:SAML:2.0:nameid-format:persistent',
                      allowed_clock_drift: 1  # for one second clock drift
              }
            }
    
  2. Save the file and restart GitLab:

    # For systems running systemd
    sudo systemctl restart gitlab.target
    
    # For systems running SysV init
    sudo service gitlab restart
    

Designate a unique attribute for the uid

Before setting the uid to a unique attribute, make sure that you have configured the following attributes so your SAML users cannot change them:

  • NameID.
  • Email when used with omniauth_auto_link_saml_user.

If users can change these attributes, they can sign in as other authorized users. See your SAML IdP documentation for information on how to make these attributes unchangeable.

By default, the uid is set as the name_id in the SAML response. To designate a unique attribute for the uid, you can set the uid_attribute. In the following example, the value of uid attribute in the SAML response is set as the uid_attribute.

Linux package (Omnibus)
  1. Edit /etc/gitlab/gitlab.rb:

    gitlab_rails['omniauth_providers'] = [
      { name: 'saml',
        label: 'Our SAML Provider',
        args: {
                assertion_consumer_service_url: 'https://gitlab.example.com/users/auth/saml/callback',
                idp_cert_fingerprint: '43:51:43:a1:b5:fc:8b:b7:0a:3a:a9:b1:0f:66:73:a8',
                idp_sso_target_url: 'https://login.example.com/idp',
                issuer: 'https://gitlab.example.com',
                name_identifier_format: 'urn:oasis:names:tc:SAML:2.0:nameid-format:persistent',
                uid_attribute: 'uid'
        }
      }
    ]
    
  2. Save the file and reconfigure GitLab:

    sudo gitlab-ctl reconfigure
    
Helm chart (Kubernetes)
  1. Put the following content in a file named saml.yaml to be used as a Kubernetes Secret:

    name: 'saml'
    label: 'Our SAML Provider'
    groups_attribute: 'Groups'
    required_groups: ['Developers', 'Freelancers', 'Admins', 'Auditors']
    args:
      assertion_consumer_service_url: 'https://gitlab.example.com/users/auth/saml/callback'
      idp_cert_fingerprint: '43:51:43:a1:b5:fc:8b:b7:0a:3a:a9:b1:0f:66:73:a8'
      idp_sso_target_url: 'https://login.example.com/idp'
      issuer: 'https://gitlab.example.com'
      name_identifier_format: 'urn:oasis:names:tc:SAML:2.0:nameid-format:persistent'
      uid_attribute: 'uid'
    
  2. Create the Kubernetes Secret:

    kubectl create secret generic -n <namespace> gitlab-saml --from-file=provider=saml.yaml
    
  3. Export the Helm values:

    helm get values gitlab > gitlab_values.yaml
    
  4. Edit gitlab_values.yaml:

    global:
      appConfig:
        omniauth:
          providers:
            - secret: gitlab-saml
    
  5. Save the file and apply the new values:

    helm upgrade -f gitlab_values.yaml gitlab gitlab/gitlab
    
Docker
  1. Edit docker-compose.yml:

    version: "3.6"
    services:
      gitlab:
        environment:
          GITLAB_OMNIBUS_CONFIG: |
            gitlab_rails['omniauth_providers'] = [
               { name: 'saml',
                 label: 'Our SAML Provider',
                 groups_attribute: 'Groups',
                 required_groups: ['Developers', 'Freelancers', 'Admins', 'Auditors'],
                 args: {
                         assertion_consumer_service_url: 'https://gitlab.example.com/users/auth/saml/callback',
                         idp_cert_fingerprint: '43:51:43:a1:b5:fc:8b:b7:0a:3a:a9:b1:0f:66:73:a8',
                         idp_sso_target_url: 'https://login.example.com/idp',
                         issuer: 'https://gitlab.example.com',
                         name_identifier_format: 'urn:oasis:names:tc:SAML:2.0:nameid-format:persistent',
                         uid_attribute: 'uid'
                 }
               }
            ]
    
  2. Save the file and restart GitLab:

    docker compose up -d
    
Self-compiled (source)
  1. Edit /home/git/gitlab/config/gitlab.yml:

    production: &base
      omniauth:
        providers:
          - { name: 'saml',
              label: 'Our SAML Provider',
              groups_attribute: 'Groups',
              required_groups: ['Developers', 'Freelancers', 'Admins', 'Auditors'],
              args: {
                      assertion_consumer_service_url: 'https://gitlab.example.com/users/auth/saml/callback',
                      idp_cert_fingerprint: '43:51:43:a1:b5:fc:8b:b7:0a:3a:a9:b1:0f:66:73:a8',
                      idp_sso_target_url: 'https://login.example.com/idp',
                      issuer: 'https://gitlab.example.com',
                      name_identifier_format: 'urn:oasis:names:tc:SAML:2.0:nameid-format:persistent',
                      uid_attribute: 'uid'
              }
            }
    
  2. Save the file and restart GitLab:

    # For systems running systemd
    sudo systemctl restart gitlab.target
    
    # For systems running SysV init
    sudo service gitlab restart
    

Assertion encryption (optional)

GitLab requires the use of TLS encryption with SAML 2.0. Sometimes, GitLab needs additional assertion encryption. For example, if you:

  • Terminate TLS encryption early at a load balancer.
  • Include sensitive details in assertions that you do not want appearing in logs.

Most organizations should not need additional encryption at this layer.

Your IdP encrypts the assertion with the public certificate of GitLab. GitLab decrypts the EncryptedAssertion with its private key.

note
This integration uses the certificate and private_key settings for both assertion encryption and request signing.

The SAML integration supports EncryptedAssertion. To encrypt your assertions, define the private key and the public certificate of your GitLab instance in the SAML settings.

When you define the key and certificate, replace all line feeds in the key file with \n. This makes the key file one long string with no line feeds.

Linux package (Omnibus)
  1. Edit /etc/gitlab/gitlab.rb:

    gitlab_rails['omniauth_providers'] = [
      { name: 'saml',
        label: 'Our SAML Provider',
        groups_attribute: 'Groups',
        required_groups: ['Developers', 'Freelancers', 'Admins', 'Auditors'],
        args: {
                assertion_consumer_service_url: 'https://gitlab.example.com/users/auth/saml/callback',
                idp_cert_fingerprint: '43:51:43:a1:b5:fc:8b:b7:0a:3a:a9:b1:0f:66:73:a8',
                idp_sso_target_url: 'https://login.example.com/idp',
                issuer: 'https://gitlab.example.com',
                name_identifier_format: 'urn:oasis:names:tc:SAML:2.0:nameid-format:persistent',
                certificate: '-----BEGIN CERTIFICATE-----\n<redacted>\n-----END CERTIFICATE-----',
                private_key: '-----BEGIN PRIVATE KEY-----\n<redacted>\n-----END PRIVATE KEY-----'
        }
      }
    ]
    
  2. Save the file and reconfigure GitLab:

    sudo gitlab-ctl reconfigure
    
Helm chart (Kubernetes)
  1. Put the following content in a file named saml.yaml to be used as a Kubernetes Secret:

    name: 'saml'
    label: 'Our SAML Provider'
    groups_attribute: 'Groups'
    required_groups: ['Developers', 'Freelancers', 'Admins', 'Auditors']
    args:
      assertion_consumer_service_url: 'https://gitlab.example.com/users/auth/saml/callback'
      idp_cert_fingerprint: '43:51:43:a1:b5:fc:8b:b7:0a:3a:a9:b1:0f:66:73:a8'
      idp_sso_target_url: 'https://login.example.com/idp'
      issuer: 'https://gitlab.example.com'
      name_identifier_format: 'urn:oasis:names:tc:SAML:2.0:nameid-format:persistent'
      certificate: '-----BEGIN CERTIFICATE-----\n<redacted>\n-----END CERTIFICATE-----'
      private_key: '-----BEGIN PRIVATE KEY-----\n<redacted>\n-----END PRIVATE KEY-----'
    
  2. Create the Kubernetes Secret:

    kubectl create secret generic -n <namespace> gitlab-saml --from-file=provider=saml.yaml
    
  3. Export the Helm values:

    helm get values gitlab > gitlab_values.yaml
    
  4. Edit gitlab_values.yaml:

    global:
      appConfig:
        omniauth:
          providers:
            - secret: gitlab-saml
    
  5. Save the file and apply the new values:

    helm upgrade -f gitlab_values.yaml gitlab gitlab/gitlab
    
Docker
  1. Edit docker-compose.yml:

    version: "3.6"
    services:
      gitlab:
        environment:
          GITLAB_OMNIBUS_CONFIG: |
            gitlab_rails['omniauth_providers'] = [
               { name: 'saml',
                 label: 'Our SAML Provider',
                 groups_attribute: 'Groups',
                 required_groups: ['Developers', 'Freelancers', 'Admins', 'Auditors'],
                 args: {
                         assertion_consumer_service_url: 'https://gitlab.example.com/users/auth/saml/callback',
                         idp_cert_fingerprint: '43:51:43:a1:b5:fc:8b:b7:0a:3a:a9:b1:0f:66:73:a8',
                         idp_sso_target_url: 'https://login.example.com/idp',
                         issuer: 'https://gitlab.example.com',
                         name_identifier_format: 'urn:oasis:names:tc:SAML:2.0:nameid-format:persistent',
                         certificate: '-----BEGIN CERTIFICATE-----\n<redacted>\n-----END CERTIFICATE-----',
                         private_key: '-----BEGIN PRIVATE KEY-----\n<redacted>\n-----END PRIVATE KEY-----'
                 }
               }
            ]
    
  2. Save the file and restart GitLab:

    docker compose up -d
    
Self-compiled (source)
  1. Edit /home/git/gitlab/config/gitlab.yml:

    production: &base
      omniauth:
        providers:
          - { name: 'saml',
              label: 'Our SAML Provider',
              groups_attribute: 'Groups',
              required_groups: ['Developers', 'Freelancers', 'Admins', 'Auditors'],
              args: {
                      assertion_consumer_service_url: 'https://gitlab.example.com/users/auth/saml/callback',
                      idp_cert_fingerprint: '43:51:43:a1:b5:fc:8b:b7:0a:3a:a9:b1:0f:66:73:a8',
                      idp_sso_target_url: 'https://login.example.com/idp',
                      issuer: 'https://gitlab.example.com',
                      name_identifier_format: 'urn:oasis:names:tc:SAML:2.0:nameid-format:persistent',
                      certificate: '-----BEGIN CERTIFICATE-----\n<redacted>\n-----END CERTIFICATE-----',
                      private_key: '-----BEGIN PRIVATE KEY-----\n<redacted>\n-----END PRIVATE KEY-----'
              }
            }
    
  2. Save the file and restart GitLab:

    # For systems running systemd
    sudo systemctl restart gitlab.target
    
    # For systems running SysV init
    sudo service gitlab restart
    

Sign SAML authentication requests (optional)

You can configure GitLab to sign SAML authentication requests. This configuration is optional because GitLab SAML requests use the SAML redirect binding.

To implement signing:

  1. Create a private key and public certificate pair for your GitLab instance to use for SAML.
  2. Configure the signing settings in the security section of the configuration. For example:

    Linux package (Omnibus)
    1. Edit /etc/gitlab/gitlab.rb:

      gitlab_rails['omniauth_providers'] = [
        { name: 'saml',
          label: 'Our SAML Provider',
          args: {
                  assertion_consumer_service_url: 'https://gitlab.example.com/users/auth/saml/callback',
                  idp_cert_fingerprint: '43:51:43:a1:b5:fc:8b:b7:0a:3a:a9:b1:0f:66:73:a8',
                  idp_sso_target_url: 'https://login.example.com/idp',
                  issuer: 'https://gitlab.example.com',
                  name_identifier_format: 'urn:oasis:names:tc:SAML:2.0:nameid-format:persistent',
                  certificate: '-----BEGIN CERTIFICATE-----\n<redacted>\n-----END CERTIFICATE-----',
                  private_key: '-----BEGIN PRIVATE KEY-----\n<redacted>\n-----END PRIVATE KEY-----',
                  security: {
                    authn_requests_signed: true,  # enable signature on AuthNRequest
                    want_assertions_signed: true,  # enable the requirement of signed assertion
                    metadata_signed: false,  # enable signature on Metadata
                    signature_method: 'http://www.w3.org/2001/04/xmldsig-more#rsa-sha256',
                    digest_method: 'http://www.w3.org/2001/04/xmlenc#sha256',
                  }
          }
        }
      ]
      
    2. Save the file and reconfigure GitLab:

      sudo gitlab-ctl reconfigure
      
    Helm chart (Kubernetes)
    1. Put the following content in a file named saml.yaml to be used as a Kubernetes Secret:

      name: 'saml'
      label: 'Our SAML Provider'
      args:
        assertion_consumer_service_url: 'https://gitlab.example.com/users/auth/saml/callback'
        idp_cert_fingerprint: '43:51:43:a1:b5:fc:8b:b7:0a:3a:a9:b1:0f:66:73:a8'
        idp_sso_target_url: 'https://login.example.com/idp'
        issuer: 'https://gitlab.example.com'
        name_identifier_format: 'urn:oasis:names:tc:SAML:2.0:nameid-format:persistent'
        certificate: '-----BEGIN CERTIFICATE-----\n<redacted>\n-----END CERTIFICATE-----'
        private_key: '-----BEGIN PRIVATE KEY-----\n<redacted>\n-----END PRIVATE KEY-----'
        security:
          authn_requests_signed: true  # enable signature on AuthNRequest
          want_assertions_signed: true  # enable the requirement of signed assertion
          metadata_signed: false  # enable signature on Metadata
          signature_method: 'http://www.w3.org/2001/04/xmldsig-more#rsa-sha256'
          digest_method: 'http://www.w3.org/2001/04/xmlenc#sha256'
      
    2. Create the Kubernetes Secret:

      kubectl create secret generic -n <namespace> gitlab-saml --from-file=provider=saml.yaml
      
    3. Export the Helm values:

      helm get values gitlab > gitlab_values.yaml
      
    4. Edit gitlab_values.yaml:

      global:
        appConfig:
          omniauth:
            providers:
              - secret: gitlab-saml
      
    5. Save the file and apply the new values:

      helm upgrade -f gitlab_values.yaml gitlab gitlab/gitlab
      
    Docker
    1. Edit docker-compose.yml:

      version: "3.6"
      services:
        gitlab:
          environment:
            GITLAB_OMNIBUS_CONFIG: |
              gitlab_rails['omniauth_providers'] = [
                 { name: 'saml',
                   label: 'Our SAML Provider',
                   args: {
                           assertion_consumer_service_url: 'https://gitlab.example.com/users/auth/saml/callback',
                           idp_cert_fingerprint: '43:51:43:a1:b5:fc:8b:b7:0a:3a:a9:b1:0f:66:73:a8',
                           idp_sso_target_url: 'https://login.example.com/idp',
                           issuer: 'https://gitlab.example.com',
                           name_identifier_format: 'urn:oasis:names:tc:SAML:2.0:nameid-format:persistent',
                           certificate: '-----BEGIN CERTIFICATE-----\n<redacted>\n-----END CERTIFICATE-----',
                           private_key: '-----BEGIN PRIVATE KEY-----\n<redacted>\n-----END PRIVATE KEY-----',
                           security: {
                             authn_requests_signed: true,  # enable signature on AuthNRequest
                             want_assertions_signed: true,  # enable the requirement of signed assertion
                             metadata_signed: false,  # enable signature on Metadata
                             signature_method: 'http://www.w3.org/2001/04/xmldsig-more#rsa-sha256',
                             digest_method: 'http://www.w3.org/2001/04/xmlenc#sha256',
                           }
                   }
                 }
              ]
      
    2. Save the file and restart GitLab:

      docker compose up -d
      
    Self-compiled (source)
    1. Edit /home/git/gitlab/config/gitlab.yml:

      production: &base
        omniauth:
          providers:
            - { name: 'saml',
                label: 'Our SAML Provider',
                args: {
                        assertion_consumer_service_url: 'https://gitlab.example.com/users/auth/saml/callback',
                        idp_cert_fingerprint: '43:51:43:a1:b5:fc:8b:b7:0a:3a:a9:b1:0f:66:73:a8',
                        idp_sso_target_url: 'https://login.example.com/idp',
                        issuer: 'https://gitlab.example.com',
                        name_identifier_format: 'urn:oasis:names:tc:SAML:2.0:nameid-format:persistent',
                        certificate: '-----BEGIN CERTIFICATE-----\n<redacted>\n-----END CERTIFICATE-----',
                        private_key: '-----BEGIN PRIVATE KEY-----\n<redacted>\n-----END PRIVATE KEY-----',
                        security: {
                          authn_requests_signed: true,  # enable signature on AuthNRequest
                          want_assertions_signed: true,  # enable the requirement of signed assertion
                          metadata_signed: false,  # enable signature on Metadata
                          signature_method: 'http://www.w3.org/2001/04/xmldsig-more#rsa-sha256',
                          digest_method: 'http://www.w3.org/2001/04/xmlenc#sha256',
                        }
                }
              }
      
    2. Save the file and restart GitLab:

      # For systems running systemd
      sudo systemctl restart gitlab.target
      
      # For systems running SysV init
      sudo service gitlab restart
      

GitLab then:

  • Signs the request with the provided private key.
  • Includes the configured public x500 certificate in the metadata for your IdP to validate the signature of the received request with.

For more information on this option, see the Ruby SAML gem documentation.

The Ruby SAML gem is used by the OmniAuth SAML gem to implement the client side of the SAML authentication.

note
The SAML redirect binding is different to the SAML POST binding. In the POST binding, signing is required to prevent intermediaries from tampering with the requests.

Password generation for users created through SAML

GitLab generates and sets passwords for users created through SAML.

Users authenticated with SSO or SAML must not use a password for Git operations over HTTPS. These users can instead:

A user can manually link their SAML identity to an existing GitLab account by following the steps in Enable OmniAuth for an existing user.

Configure group SAML SSO on a self-managed instance

Use group SAML SSO if you have to allow access through multiple SAML IdPs on your self-managed instance.

To configure group SAML SSO:

Linux package (Omnibus)
  1. Make sure GitLab is configured with HTTPS.
  2. Edit /etc/gitlab/gitlab.rb to enable OmniAuth and the group_saml provider:

    gitlab_rails['omniauth_enabled'] = true
    gitlab_rails['omniauth_providers'] = [{ name: 'group_saml' }]
    
  3. Save the file and reconfigure GitLab:

    sudo gitlab-ctl reconfigure
    
Helm chart (Kubernetes)
  1. Make sure GitLab is configured with HTTPS.
  2. Put the following content in a file named group_saml.yaml to be used as a Kubernetes Secret:

    name: 'group_saml'
    
  3. Create the Kubernetes Secret:

    kubectl create secret generic -n <namespace> gitlab-group-saml --from-file=provider=group_saml.yaml
    
  4. Export the Helm values:

    helm get values gitlab > gitlab_values.yaml
    
  5. Edit gitlab_values.yaml to enable OmniAuth and the group_saml provider:

    global:
      appConfig:
        omniauth:
          enabled: true
          providers:
            - secret: gitlab-group-saml
    
  6. Save the file and apply the new values:

    helm upgrade -f gitlab_values.yaml gitlab gitlab/gitlab
    
Docker
  1. Make sure GitLab is configured with HTTPS.
  2. Edit docker-compose.yml to enable OmniAuth and the group_saml provider:

    version: "3.6"
    services:
      gitlab:
        environment:
          GITLAB_OMNIBUS_CONFIG: |
            gitlab_rails['omniauth_enabled'] = true
            gitlab_rails['omniauth_providers'] = [{ name: 'group_saml' }]
    
  3. Save the file and restart GitLab:

    docker compose up -d
    
Self-compiled (source)
  1. Make sure GitLab is configured with HTTPS.
  2. Edit /home/git/gitlab/config/gitlab.yml to enable OmniAuth and the group_saml provider:

    production: &base
      omniauth:
        enabled: true
        providers:
          - { name: 'group_saml' }
    
  3. Save the file and restart GitLab:

    # For systems running systemd
    sudo systemctl restart gitlab.target
    
    # For systems running SysV init
    sudo service gitlab restart
    

As a multi-tenant solution, group SAML on a self-managed instance is limited compared to the recommended instance-wide SAML. Use instance-wide SAML to take advantage of:

Additional configuration for SAML apps on your IdP

When configuring a SAML app on the IdP, your IdP may need additional configuration, such as the following:

FieldValueNotes
SAML profileWeb browser SSO profileGitLab uses SAML to sign users in through their browser. No requests are made directly to the IdP.
SAML request bindingHTTP RedirectGitLab (the SP) redirects users to your IdP with a base64 encoded SAMLRequest HTTP parameter.
SAML response bindingHTTP POSTSpecifies how the SAML token is sent by your IdP. Includes the SAMLResponse, which a user’s browser submits back to GitLab.
Sign SAML responseRequiredPrevents tampering.
X.509 certificate in responseRequiredSigns the response and checks the response against the provided fingerprint.
Fingerprint algorithmSHA-1GitLab uses a SHA-1 hash of the certificate to sign the SAML Response.
Signature algorithmSHA-1/SHA-256/SHA-384/SHA-512Determines how a response is signed. Also known as the digest method, this can be specified in the SAML response.
Encrypt SAML assertionOptionalUses TLS between your identity provider, the user’s browser, and GitLab.
Sign SAML assertionOptionalValidates the integrity of a SAML assertion. When active, signs the whole response.
Check SAML request signatureOptionalChecks the signature on the SAML response.
Default RelayStateOptionalSpecifies the URL users should end up on after successfully signing in through SAML at your IdP.
NameID formatPersistentSee NameID format details.
Additional URLsOptionalMay include the issuer, identifier, or assertion consumer service URL in other fields on some providers.

For example configurations, see the notes on specific providers.

Glossary of common terms

TermDescription
Identity provider (IdP)The service that manages your user identities, such as Okta or OneLogin.
Service provider (SP)Consumes assertions from a SAML IdP, such as Okta, to authenticate users. You can configure GitLab as a SAML 2.0 SP.
AssertionA piece of information about a user’s identity, such as their name or role. Also known as a claim or an attribute.
Single Sign-On (SSO)Name of the authentication scheme.
Assertion consumer service URLThe callback on GitLab where users are redirected after successfully authenticating with the IdP.
IssuerHow GitLab identifies itself to the IdP. Also known as a “Relying party trust identifier”.
Certificate fingerprintConfirms that communications over SAML are secure by checking that the server is signing communications with the correct certificate. Also known as a certificate thumbprint.

Troubleshooting

See our troubleshooting SAML guide.