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Duo Protection for Marketo 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 Marketo SSO logins, complete with inline self-service enrollment and Duo Prompt.

Duo Access Gateway will reach end of life in October 2023. Customers may not create new DAG applications after May 19, 2022. 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 Marketo 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 Marketo, try the DAG to Duo SSO application migration process.

Marketo requires Duo Access Gateway version 1.2.1 or greater. Please upgrade your Duo Access Gateway before attempting to use Marketo.


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 Marketo 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 Marketo.

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 Marketo. 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 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 another directory attribute than the ones listed here then enter that attribute name instead. If you've already configured the attributes list for another cloud service provider, append the additional attributes not already present to the list, separated by a comma.

  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 Marketo when configuring SSO. Click the Download Certificate link to obtain the token signing certificate (the downloaded file is named "dag.crt").

    DAG Metadata Information

Enable Marketo SSO

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

  1. Log on to Marketo as an administrative user and navigate to AdminIntegrationSingle Sign-On. Click the Edit button next to SAML Settings.

  2. When the Edit SAML Settings window appears change SAML Single Sign-On to Enabled.

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


  4. Copy the SSO URL information from the Duo Access Gateway admin console Metadata display and paste it into the Marketo Entity ID field.


  5. Choose In Name identifier element of Subject for the User ID Location option.

  6. The "Identity Provider Certificate" is the DAG Metadata certificate supplied by Duo Access Gateway. Click Browse... to select the dag.crt file you downloaded from the DAG admin console "Application" page earlier.

  7. After you've entered all the required information click Save.

    Marketo Single Sign-On Settings
  8. On the SSO Settings page click Edit next to Redirect Pages.

  9. When the Redirect Pages window appears copy the Logout URL information from the Duo Access Gateway admin console Metadata display and paste it into the Marketo Logout URL field.


  10. Copy the Error URL information from the Duo Access Gateway admin console Metadata display and paste it into the Marketo Error URL field.

    Example: https://yourserver.example/dag/module.php/duosecurity/duo_error.php

  11. After you've entered all the required information click Save.

    Marketo Single Sign-On Settings
  12. You can force users to sign in with SSO by navigating to AdminLogin Settings. Click Edit next to Security Settings. Click Advanced and check the box next to Require SSO. Click Save.

Learn more about Marketo SSO at the Marketo Docs Site.

Create the Marketo 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 Marketo 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 Marketo. See Protecting Applications for more information about protecting applications in Duo and additional application options.

  3. Find your Marketo Munchkin Account ID under AdminIntegrationMunchkin. It will be located under Tracking Code, an example is 012-ABC-345. Copy this into the Munchkin Account ID field (dashes included) in the Duo Admin Panel.

  4. Marketo 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 when done.

    Duo Marketo 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 Marketo 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 Marketo 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 Marketo SAML application JSON file you downloaded from the Duo Admin Panel earlier. Click the Upload button after selecting the JSON configuration file.

  3. The Marketo SAML application is added.

    Marketo Application Added

Verify SSO

You can log on to Marketo with IdP-initiated SSO via Duo Access Gateway using the Login URL provided by the DAG server when you created the Marketo application in the DAG admin console (

You will be directed to your configured Authentication Source login page. Login with your username and password, approve the prompt for Duo two-factor authentication, and then you are forwarded to the Marketo site.

DAG Login and Authentication Prompt

Congratulations! Your Marketo 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.

Marketo does not support SP-initiated SSO login at this time.

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 Marketo. Learn more about configuring Marketo SSO with AD FS at the Marketo Docs Site.

After you have successfully configured and tested AD FS SSO login to Marketo 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 Marketo.

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.