Duo Single Sign-On for Checkmk

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 Checkmk 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 Checkmk.

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 Checkmk. Duo checks the user, device, and network against an application's policy before allowing access to the application.

Configure Single Sign-On

Before configuring Checkmk 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 Checkmk application in Duo.

Create the Checkmk Application in Duo

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

2. Locate the entry for Checkmk 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 Checkmk. See Protecting Applications for more information about protecting applications with Duo and additional application options. You'll need the information on the Checkmk page under Downloads later.

3. Checkmk uses the Mail attribute, Username attribute, and Display 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
   <Username>	sAMAccountName	Username
   <Display Name>	displayName	DisplayName

   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.

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 Checkmk 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 Checkmk 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 Checkmk for SSO

1. Log into your Checkmk account as an administrator.

2. In the left menu sidebar, click Setup.

3. Under "Users", click SAML authentication. The "SAML connections" page opens.

4. Click Add connection. The "SAML authentication" page opens.

5. Click General properties to expand the section.

6. Enter a unique name for your connection into the Connection ID field.

7. Enter a unique name for your Checkmk login button into the Name field.

8. Return to the Duo Admin Panel. Under "Downloads", click Download XML.

9. Return to the Checkmk "SAML authentication" section. Click Connection to expand the section.

10. Click the Identity provider metadata drop-down menu and select Upload XML file.

11. Click Choose File and open the XML file you downloaded from Duo earlier.

12. In your web address bar, copy the server URL and paste it into the Checkmk server URL field.

    Example: If the URL in your web address bar is https://ec1-23-456-789-012.compute-1.amazonaws.com/monitoring/check_mk, then your server URL is https://ec1-23-456-789-012.compute-1.amazonaws.com.

13. Scroll down and click Users to expand the section.

14. Type userName into the User ID attribute field.

15. Type displayName into the Full name attribute field.

16. Type mail into the E-mail address attribute field.

17. At the top of the page, click Save. The "SAML connections" page opens.

18. In the "Actions" column, click the Edit this connection icon next to your created connection ID. The "SAML authentication" page opens.

19. Click Checkmk service provider metadata (generated automatically) to expand the section.

20. Copy the Entity ID and paste it into the Duo Admin Panel Entity ID field, under "Service Provider".

21. Return to the Checkmk service provider metadata (generated automatically) section. Copy the Assertion Consumer Service endpoint and paste it into the Duo Admin Panel Assertion Consumer Service Endpoint field.

    

22. In the Duo Admin Panel, scroll to the bottom of the page and click Save.

Learn more about Checkmk SSO at Checkmk Docs.

Using SSO

You can log on to Checkmk by navigating to your Checkmk SSO page e.g., https://ec1-23-456-789-012.compute-1.amazonaws.com/monitoring. Click Login with (your button name) 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 Checkmk to complete the login process.

* Universal Prompt experience shown.

Checkmk supports SP-initiated authentication only, meaning that you must start your SSO login from that application's sign-in page. You won't be able to add Checkmk as an application tile in Duo Central for IdP-initiated logins.

Congratulations! Your Checkmk 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 Checkmk 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.