Duo Single Sign-On for GitLab SaaS

Overview

As business applications move from on-premises to cloud hosted solutions, users experience password fatigue due to disparate logons for different applications. Single sign-on (SSO) technologies seek to unify identities across systems and reduce the number of different credentials a user has to remember or input to gain access to resources.

While SSO is convenient for users, it presents new security challenges. If a user's primary password is compromised, attackers may be able to gain access to multiple resources. In addition, as sensitive information makes its way to cloud-hosted services it is even more important to secure access by implementing two-factor authentication and zero-trust policies.

About Duo Single Sign-On

Duo Single Sign-On is our cloud-hosted SSO product which layers Duo's strong authentication and flexible policy engine on top of GitLab SaaS logins. Duo Single Sign-On acts as an identity provider (IdP), authenticating your users using existing on-premises Active Directory (AD) or another SSO IdP. Duo SSO prompts users for two-factor authentication and performs endpoint assessment and verification before permitting access to GitLab SaaS.

Duo Single Sign-On is available in Duo Premier, Duo Advantage, and Duo Essentials plans, which also include the ability to define policies that enforce unique controls for each individual SSO application. For example, you can require that Salesforce users complete two-factor authentication at every login, but only once every seven days when accessing GitLab SaaS. Duo checks the user, device, and network against an application's policy before allowing access to the application.

Configure Single Sign-On

Before configuring GitLab SaaS with Duo SSO using Security Assertion Markup Language (SAML) 2.0 authentication you'll first need to enable Duo Single Sign-On for your Duo account and configure a working authentication source.

Once you have your SSO authentication source working, continue to the next step of creating the GitLab SaaS application in Duo.

Create the GitLab SaaS Application in Duo

1. Log on to the Duo Admin Panel and navigate to Applications → Protect an Application.

2. Locate the entry for GitLab SaaS with a protection type of "2FA with SSO hosted by Duo (Single Sign-On)" in the applications list. Click Protect to the far-right to start configuring GitLab SaaS. See Protecting Applications for more information about protecting applications with Duo and additional application options. You'll need the information on the GitLab SaaS page under Downloads later.

3. GitLab SaaS uses the Mail attribute, First name attribute, and Last name attribute when authenticating. We've mapped the bridge attributes to Duo Single Sign-On supported authentication source attributes as follows:

   Bridge Attribute	Active Directory	SAML IdP
   <Email Address>	mail	Email
   <First Name>	givenName	FirstName
   <Last Name>	sn	LastName

   If you are using non-standard attributes for your authentication source, check the Custom attributes box and enter the name of the attributes you wish to use instead.

4. You can adjust additional settings for your new SAML application at this time — like changing the application's name from the default value, enabling self-service, or assigning a group policy.

5. Keep the Duo Admin Panel tab open. You will come back to it later.

Duo Universal Prompt

The Duo Universal Prompt provides a simplified and accessible Duo login experience for web-based applications, offering a redesigned visual interface with security and usability enhancements.

Universal Prompt	Traditional Prompt

The Duo GitLab SaaS application supports the Universal Prompt by default, so there's no additional action required on your part to start using the newest authentication experience.

Activate Universal Prompt

Activation of the Universal Prompt is a per-application change. Activating it for one application does not change the login experience for your other Duo applications. Universal Prompt is already activated for new GitLab SaaS applications at creation.

The "Universal Prompt" area of the application details page shows that this application's status is "Activation complete", with these activation control options:

• Show traditional prompt: Your users experience Duo's traditional prompt via redirect when logging in to this application.
• Show new Universal Prompt: (Default) Your users experience the Universal Prompt via redirect when logging in to this application.

The application's Universal Prompt status shows "Activation complete" both here and on the Universal Prompt Update Progress report.

For the time being, you may change this setting to Show traditional prompt to use the legacy experience. Keep in mind that support for the traditional Duo prompt ended for the majority of applications in March 2024. This option will be removed in the future.

Universal Update Progress

Click the See Update Progress link to view the Universal Prompt Update Progress report. This report shows the update availability and migration progress for all your Duo applications. You can also activate the new prompt experience for multiple supported applications from the report page instead of visiting the individual details pages for each application.

Enable GitLab SaaS for SSO

1. Log into your GitLab SaaS account as an administrative user.

2. In the left menu sidebar, click Groups.

3. The "Groups" page opens. Click your group.

4. In the left menu sidebar, click Settings. Scroll down the left menu sidebar and click SAML SSO.

5. Return to the Duo Admin Panel. Under "Metadata", copy the Identity provider single sign-on URL and paste it into the GitLab SaaS Identity provider single sign-on URL field under "Configuration".

   

6. Return to the Duo Admin Panel. Under "Certificate Fingerprints", copy the Certificate fingerprint and paste it into the GitLab SaaS Certificate fingerprint field.

   

7. In your GitLab SaaS account page, click Save changes.

   

8. In the "SAML Single Sign On" section, copy your group name and paste it into the Duo Admin Panel Group Name field under "Service Provider". If your group name is common, a unique number may be automatically added to it. Make sure you include this number with your group name.

   

9. Scroll to the bottom of the page and click Save.

10. Return to your GitLab SaaS account page. Scroll down to the "Configuration" section and click Verify SAML Configuration.

Learn more about GitLab SaaS SSO at GitLab Docs.

Using SSO

You can log on to GitLab SaaS by navigating to your GitLab SaaS SSO page e.g., https://gitlab.com/groups/yourgroup. Click Sign in to be redirected to Duo Single Sign-On to begin authentication.

Active Directory Login

With Active Directory as the Duo SSO authentication source, enter the primary username (email address) on the Duo SSO login page and click or tap Next.

Enter the AD primary password and click or tap Log in to continue.

Enable Duo Passwordless to log in to Duo SSO backed by Active Directory authentication without entering a password in the future.

SAML Login

With another SAML identity provider as the Duo SSO authentication source, Duo SSO immediately redirects the login attempt to that SAML IdP for primary authentication. Users do not see the Duo SSO primary login screen.

Duo Authentication

Successful verification of your primary credentials by Active Directory or a SAML IdP redirects back to Duo. Complete Duo two-factor authentication when prompted and then you'll return to GitLab SaaS to complete the login process.

* Universal Prompt experience shown.

You can also log into GitLab SaaS using Duo Central, our cloud-hosted portal which allows users to access all of their applications in one spot. Link to GitLab SaaS in Duo Central by adding it as an application tile. Once the tile has been added, log into Duo Central and click the tile for IdP-initiated authentication to GitLab SaaS.

Congratulations! Your GitLab SaaS users now authenticate using Duo Single Sign-On.

See the full user login experience, including expired password reset (available for Active Directory authentication sources) in the Duo End User Guide for SSO.

Enable Remembered Devices

To minimize additional Duo two-factor prompts when switching between GitLab SaaS and your other Duo Single Sign-On SAML applications, be sure to apply a shared "Remembered Devices" policy to your SAML applications.

Troubleshooting

Need some help? Try searching our Knowledge Base articles or Community discussions. For further assistance, contact Support.