Duo Protection for Greenhouse with Duo Access Gateway

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.

Duo Access Gateway

Duo Access Gateway (DAG), our on-premises SSO product, layers Duo's strong authentication and flexible policy engine on top of Greenhouse 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 Greenhouse.

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 Greenhouse. 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 your primary authentication source.

2. Add the attributes from the table below that correspond to the Duo attributes Mail attribute, Last name attribute, and First name attribute in the "Attributes" field when configuring your Active Directory or OpenLDAP authentication source in the DAG admin console, separated by a comma. For example, if Active Directory is your authentication source, enter mail,sn,givenName in the "Attributes" field.

   Duo Attribute	Active Directory	OpenLDAP
   Mail attribute	mail	mail
   First name attribute	givenName	gn
   Last name attribute	sn	sn

   If your organization uses other directory attributes than the ones listed here then enter those attribute names 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 Greenhouse when configuring SSO.

   

Enable Greenhouse SSO

Greenhouse SSO cannot be configured from the administrator interface. Contact Greenhouse support to have your account enabled for SSO, sending in the SHA-1 Fingerprint and SSO URL from the DAG admin console. Continue with configuration once Greenhouse enables SSO for your account.

More information about Greenhouse's SSO support is available at the Greenhouse Support Site.

Create the Greenhouse Application in Duo

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

2. Locate the entry for Greenhouse 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 Greenhouse. See Protecting Applications for more information about protecting applications in Duo and additional application options.

3. Enter the subdomain used when logging into your company's Greenhouse portal as the Subdomain name. For example, if your Greenhouse login URL is https://yourdomain.greenhouse.io then enter yourdomain.

4. Greenhouse uses the Mail attribute, First name attribute, and Last name attribute when authenticating. We've mapped those to DAG supported authentication source attributes as follows:

   Duo Attribute	Active Directory	OpenLDAP	SAML IdP	Google	Azure
   Mail attribute	mail	mail	mail	email	mail
   First name attribute	givenName	gn	givenName	given_name	givenName
   Last name attribute	sn	sn	sn	family_name	surname

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

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

   

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

3. The Greenhouse SAML application is added.

   

Verify SSO

You can log on to Greenhouse using your organization’s domain login page e.g. https://yourdomain.greenhouse.io. 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 Greenhouse site after authenticating.

Congratulations! Your Greenhouse users now authenticate using Duo Access Gateway.

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 Greenhouse. Learn more about configuring Greenhouse SSO with AD FS at the Greenhouse Support Site.

After you have successfully configured and tested AD FS SSO login to Greenhouse using your AD domain credentials, you can then install the Duo AD FS integration. AD FS protection is included with Duo Essentials, Duo Advantage, and Duo Premier 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 Greenhouse.

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.

Troubleshooting

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