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Duo Protection for for Business with Duo Access Gateway

Last Updated: February 15th, 2022

Duo offers a variety of methods for adding two-factor authentication and flexible security policies to for Business SSO logins, complete with inline self-service enrollment and Duo Prompt.

Duo Access Gateway reached Last Day of Support on October 26, 2023 for Duo Essentials, Advantage, and Premier customers. After that date, Duo Support may only assist with the migration of existing Duo Access Gateway applications to Duo Single Sign-On. Please see the Guide to Duo Access Gateway end of life for more details.

Use the Duo Single Sign-on Generic Service Provider application to protect for Business with Duo Single Sign-On, our cloud-hosted identity provider featuring Duo Central and the Duo Universal Prompt.

If you already use Duo Access Gateway to protect for Business, try the DAG to Duo SSO application migration process.

This documentation is for hosted for Business. If you are looking to protect on-premises GitHub Enterprise please visit Duo Protection for GitHub Enterprise.


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.

Duo Access Gateway

Duo Access Gateway (DAG), our on-premises SSO product, layers Duo's strong authentication and flexible policy engine on top of for Business logins using the Security Assertion Markup Language (SAML) 2.0 authentication standard. Duo Access Gateway acts as an identity provider (IdP), authenticating your users using existing on-premises or cloud-based directory credentials and prompting for two-factor authentication before permitting access to for Business.

Duo Access Gateway is included in the 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 for Business. Duo checks the user, device, and network against an application's policy before allowing access to the application.

Deploy or Update Duo Access Gateway

  1. Install Duo Access Gateway on a server in your DMZ. Follow our instructions for deploying the server, configuring DAG settings, and adding an Authentication Source.

  2. Add the attribute from the table below that corresponds to the Duo attribute Mail attribute in the "Attributes" field when configuring your Active Directory or OpenLDAP authentication source in the DAG admin console. For example, if Active Directory is your authentication source, enter mail in the "Attributes" field.

    Duo Attribute Active Directory OpenLDAP
    Mail attribute mail mail

    If your organization uses other directory attributes than the one listed here then enter those attribute names instead. If you've already configured the attributes list for another cloud service provider, append this additional attribute to the list.

  3. After completing the initial DAG configuration steps, click Applications on the left side of the Duo Access Gateway admin console.

  4. Scroll down the Applications page to the Metadata section. This is the information you need to provide to for Business when configuring SSO. Click the Download Certificate link to obtain the token signing certificate (the downloaded file is named "dag.crt").

    DAG Metadata Information

Create the for Business Application in Duo

  1. Log on to the Duo Admin Panel and navigate to Applications.

  2. Click Protect an Application and locate the entry for for Business with a protection type of "2FA with SSO self-hosted (Duo Access Gateway)" in the applications list. Click Protect to the far-right to start configuring for Business. See Protecting Applications for more information about protecting applications in Duo and additional application options.

  3. The Organization Name is the organization name used in your GitHub URL. Example: If your organization's GitHub URL is you would enter yourcompany.

  4. for Business uses the Mail attribute when authenticating. We've mapped Mail attribute to DAG supported authentication source attributes as follows:

    Duo Attribute Active Directory OpenLDAP SAML IdP Google Azure
    Mail attribute mail mail mail email mail

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

  5. Click Save Configuration to generate a downloadable configuration file.

    Duo for Business Application Settings
  6. 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 — or come back and change the application's policies and settings after you finish SSO setup. If you do update any settings, click the Save Changes button when done.

  7. Click the Download your configuration file link to obtain the for Business application settings (as a JSON file).

    Important: This file contains information that uniquely identifies this application to Duo. Secure this file as you would any other sensitive or password information. Don't share it with unauthorized individuals or email it to anyone under any circumstances!

Add the for Business Application to Duo Access Gateway

Before you do this, verify that you updated the "Attributes" list for your Duo Access Gateway authentication source as specified here.

  1. Return to the Applications page of the DAG admin console session.

  2. Click the Choose File button in the "Add Application" section of the page and locate the for Business SAML application JSON file you downloaded from the Duo Admin Panel earlier. Click the Upload button after selecting the JSON configuration file.

  3. The for Business SAML application is added. for Business Application Added

Enable for Business SSO

Add the Duo Access Gateway as a new single sign-on provider for for Business.

  1. Log into as a user who has organizational administration access for the organization you'd like to apply SSO.

  2. Click on your user icon in the upper right-hand side of the screen. Click settings from the drop-down.

  3. Click the name of your organization under "Organization settings" in the bottom left-hand side of the screen.

  4. On the "Organization settings" page click Security on the left-hand side navigation screen.

  5. Under "SAML single sign-on" check the box next to Enable SAML authentication. New options will appear.

  6. Copy the SSO URL information from the Duo Access Gateway admin console Metadata display and paste it into the for Business SSO Sign on URL field.


  7. Copy the Entity ID URL from the Duo Access Gateway admin console metadata display and paste it into the for Business SSO Issuer field.


  8. The Public certificate is the DAG Metadata certificate supplied by Duo Access Gateway. Open the dag.crt file in a text editor (like Notepad), and copy the entire contents of the file (including the -----BEGIN CERTIFICATE----- and -----END CERTIFICATE----- lines). Paste the certificate file text into this field.

  9. Click the pencil icon and set the Signature Method to RSA-SHA256 and Digest Method to SHA256. The sentence should read Your SAML provider is using the RSA-SHA256 Signature Method and the SHA256 Digest Method.

    Note: You should do this even if it already states that it is set to RSA-SHA256 before clicking the pencil.

  10. Click Save. for Business Single Sign-On Setting Edit

Learn more about for Business SSO by visiting GitHub Help.

Test SSO

  1. Click Test SAML configuration. This redirects to the Duo Access Gateway login page. Enter your primary directory logon information, approve Duo two-factor authentication, and get redirected back to the for Business site after authenticating.

  2. Upon successful authentication you'll see the message Passed: Successfully authenticated your SAML SSO identity next to the "Test SAML configuration" button.

Enforce SSO

You can enforce SSO login on your GitHub organization. When you enable this feature it removes all users and bots from your GitHub organization who have not authenticated with SSO yet. They will need to authenticate with SSO to be added back to the GitHub organization.

  1. Before you can enforce SSO you must log into the organization successfully once using SSO. Log out of your GitHub account.

  2. Log into your GitHub account. Navigate to your organization. You'll be prompted to redirect to the Duo Access Gateway to authenticate. Click Continue. This redirects to the Duo Access Gateway login page. Enter your primary directory logon information, approve Duo two-factor authentication, and get redirected back to the for Business site after authenticating.

  3. Click on your user icon in the upper right-hand side of the screen. Click settings from the drop-down.

  4. Click the name of your organization under "Organization settings" in the bottom left-hand side of the screen.

  5. On the "Organization settings" click Security on the left-hand side navigation screen.

  6. Under "SAML single sign-on" check the box next to Require SAML SSO authentication for all members of the yourcompany organization.

  7. Click Save. You'll be redirected to a page with your single sign-on recovery codes. All users in the organization that have not logged in with SSO will be removed and e-mailed with instructions on how to log back into your GitHub organization. for Business Enforce SSO

Learn more about enforcing SSO at GitHub Help.

Log in with SSO

If your organization enabled the Duo Access Gateway portal, log into the portal page using the link provided by your administrator. Click for Business from the dashboard to access the application.

When you attempt to access your organization from GitHub directly, you will also be prompted to log in with SSO. Click Continue. This redirects to the Duo Access Gateway login page. Enter your primary directory logon information, approve Duo two-factor authentication, and get redirected back to the for Business site after authenticating.

DAG Login and Authentication Prompt for Business will automatically provision accounts for new users that successfully authenticate with the Duo Access Gateway if you have unassigned for Business licenses.

Congratulations! Your for Business users now authenticate using Duo Access Gateway.

Configure Allowed Hostnames

If you plan to permit use of WebAuthn authentication methods (security keys, U2F tokens, or Touch ID) in the traditional Duo Prompt, Duo recommends configuring allowed hostnames for this application and any others that show the inline Duo Prompt before onboarding your end-users.

The Duo Universal Prompt has built-in protection from unauthorized domains so this setting does not apply.

Microsoft AD FS

Microsoft's Active Directory Federation Services (AD FS) is a popular choice for SSO because it easily integrates with the AD identity store many organizations already have deployed. Duo's support for cloud applications and SSO drops in to an existing AD FS installation to provide secondary authentication after a user passes primary authentication (successful Active Directory logon).

If you don't already have AD federation running the first step is to install and configure Microsoft AD FS in your organization. Deployment Guides for AD FS versions 2.1, and 3.0/4.0 are available from Microsoft.

Once your AD FS services are up and running, the second step is to configure the SSO partnership between your AD FS service and the external cloud resource, in this case for Business. Learn more about configuring for Business SSO with AD FS at the Help site.

After you have successfully configured and tested AD FS SSO login to for Business using your AD domain credentials, you can then install the Duo AD FS integration. AD FS protection is included with Duo's paid plans.

With the Duo integration for AD FS installed, users pass primary authentication to the AD FS service as usual. Once primary authentication succeeds, users are forwarded to the Duo service for secondary authentication. After approving logon using one of Duo's authentication methods, the user is fully logged in to for Business.

Other Identity Partners

Using a third-party SSO provider for cloud application access? Duo partners with leading cloud SSO providers like Okta and OneLogin to secure access with our strong and flexible authentication platform.

You can also use Duo two-factor authentication with CAS and Shibboleth on-premises IdPs.


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