Array AG SSL VPN

First Steps

Before moving on to the deployment steps, it's a good idea to familiarize yourself with Duo administration concepts and features like options for applications, available methods for enrolling Duo users, and Duo policy settings and how to apply them. See all Duo Administrator documentation.

You should already have a working primary authentication configuration for your Array AG SSL VPN users before you begin to deploy Duo.

To integrate Duo with your Array AG SSL VPN, you will need to install a local Duo proxy service on a machine within your network. This Duo proxy server will receive incoming RADIUS requests from your Array AG SSL VPN, contact your existing local LDAP/AD or RADIUS server to perform primary authentication, and then contact Duo's cloud service for secondary authentication.

If you are already running a Duo Authentication Proxy server in your environment, you can use that existing host for additional applications, appending the new configuration sections to the current config. You don't have to set up a new Authentication Proxy server for each application you create. However, there are some cases where it might make sense for you to deploy a new proxy server for a new application, like if you want to co-locate the Duo proxy with the application it will protect in the same data center.

We recommend the following operating systems for the system hosting the Duo Authentication Proxy:

• Windows Server 2016 or later
• CentOS 7
• CentOS Stream 8 or later
• Fedora 37 or later
• Red Hat Enterprise Linux 7 or later
• Ubuntu 20.04 LTS or later
• Debian 11 or later

The Duo End of Sale, Last Date of Support, and End of Life Policy states that Duo does not offer support for integrations running on operating system versions beyond the vendor’s stated Last Date of Support date.

See detailed Authentication Proxy operating system performance recommendations in the Duo Authentication Proxy Reference.

We do not recommend installing the Duo Authentication Proxy on the same Windows server that acts as your Active Directory domain controller or one with the Network Policy Server (NPS) role. If you must co-locate the Duo Authentication Proxy with these services, be prepared to resolve potential LDAP or RADIUS port conflicts between the Duo service and your pre-existing services.

Then you'll need to:

1. Sign up for a Duo account.
2. Log in to the Duo Admin Panel and navigate to Applications.
3. Click Protect an Application and locate the entry for Array SSL VPN with a protection type of "2FA" in the applications list. Click Protect to get your integration key, secret key, and API hostname. You'll need this information to complete your setup. See Protecting Applications for more information about protecting applications in Duo and additional application options.

You also need to download the custom Duo theme for the AG from the Array site. An Array support portal login is required.

Install the Duo Authentication Proxy

If you will reuse an existing Duo Authentication Proxy server for this new application, you can skip the install steps and go to Configure the Proxy.

The Duo Authentication Proxy can be installed on a physical or virtual host. We recommend a system with at least 1 CPU, 200 MB disk space, and 4 GB RAM (although 1 GB RAM is usually sufficient). See additional Authentication Proxy performance recommendations in the Duo Authentication Proxy Reference.

We do not recommend installing the Duo Authentication Proxy on the same Windows server that acts as your Active Directory domain controller or one with the Network Policy Server (NPS) role. If you must co-locate the Duo Authentication Proxy with these services, be prepared to resolve potential LDAP or RADIUS port conflicts between the Duo service and your pre-existing services.

duoauthproxy-version.exe /S

duoauthproxy-version.exe /S /exclude-auth-proxy-manager

sudo ./duoauthproxy-build/install --install-dir /opt/duoauthproxy --service-user duo_authproxy_svc --log-group duo_authproxy_grp --create-init-script yes

Configure the Proxy

After the installation completes, you will need to configure the proxy.

The Duo Authentication Proxy configuration file is named authproxy.cfg, and is located in the conf subdirectory of the proxy installation. With default installation paths, the proxy configuration file will be located at:

Note that as of v4.0.0, the default file access on Windows for the conf directory is restricted to the built-in Administrators group during installation.

The configuration file is formatted as a simple INI file. Section headings appear as:

[section]

Individual properties beneath a section appear as:

name=value

The Authentication Proxy may include an existing authproxy.cfg with some example content. For the purposes of these instructions, however, you should delete the existing content and start with a blank text file.

Duo Authentication Proxy Manager

The Duo Authentication Proxy Manager is a Windows utility for managing the Authentication Proxy installation on the Windows server where you install the Authentication Proxy. The Proxy Manager comes with Duo Authentication Proxy for Windows version 5.6.0 and later.

The Proxy Manager cannot manage remote Duo Authentication Proxy servers, nor can you install the Proxy Manager as a stand-alone application. There is no Proxy Manager available for Linux. The Proxy Manager only functions as part of a local Duo Authentication Proxy installation on Windows servers.

Learn more about using the Proxy Manager in the Duo Authentication Proxy Reference before you continue.

To launch the Proxy Manager utility:

• Open the Start Menu and go to Duo Security.
• Click the Duo Authentication Proxy Manager icon to launch the application. You must have administrative privileges on the Windows server and accept the prompt for elevation.
• The Proxy Manager launches and automatically opens the %ProgramFiles%\Duo Security Authentication Proxy\conf\authproxy.cfg file for editing.

Use the Proxy Manager editor on the left to make the authproxy.cfg changes in these instructions. As you type into the editor, the Proxy Manager will automatically suggest configuration options. Accepting these suggestions helps make sure you use the correct option syntax.

As you follow the instructions on this page to edit the Authentication Proxy configuration, you can click Validate to verify your changes (output shown on the right).

When you complete the Authentication Proxy configuration steps in this document, you can use the Save button to write your updates to authproxy.cfg, and then use the authproxy.cfg button to start the Authentication Proxy service before continuing on to the next configuration steps.

If you do not use the Proxy Manager to edit your configuration then we recommend using WordPad or another text editor instead of Notepad when editing the config file on Windows.

Configure the Proxy for Your Primary Authenticator

In this step, you'll set up the Proxy's primary authenticator — the system which will validate users' existing passwords. Determine which type of primary authentication you'll be using, and create either an Active Directory/LDAP [ad_client] client section, or a RADIUS [radius_client] section as follows.

Active Directory

Add an [ad_client] section if you'd like to use an Active Directory domain controller (DC) or LDAP-based directory server to perform primary authentication. This section accepts the following options:

Required

search_dn=DC=example,DC=com

Optional

security_group_dn=CN=DuoVPNUsers,OU=Groups,DC=example,DC=com

For example:

[ad_client]
host=1.2.3.4
host_2=1.2.3.5
service_account_username=duoservice
service_account_password=password1
search_dn=DC=example,DC=com
security_group_dn=CN=DuoVPNUsers,OU=Groups,DC=example,DC=com

For advanced Active Directory configuration, see the full Authentication Proxy documentation.

RADIUS

To use RADIUS as your primary authenticator, add a [radius_client] section to the top of your config file. Then add the following properties to the section:

Required

Optional

For example:

[radius_client]
host=1.2.3.4
host_2=1.2.3.5
secret=radiusclientsecret

In addition, make sure that the RADIUS server is configured to accept authentication requests from the Authentication Proxy.

For advanced RADIUS configuration, see the full Authentication Proxy documentation.

Configure the Proxy for Your Array AG SSL VPN

Next, we'll set up the Authentication Proxy to work with your Array AG SSL VPN. Create a [radius_server_iframe] section and add the properties listed below. If you've already set up the Duo Authentication Proxy for a different RADIUS iframe application, append a number to the section header to make it unique, like [radius_server_iframe2].

Required

Optional

A completed config file, using Active Directory as the primary authenticator, should look something like:

[ad_client]
host=1.2.3.4
service_account_username=duoservice
service_account_password=password1
search_dn=cn=Users,dc=example,dc=com
 
[radius_server_iframe]
type=array
ikey=DIXXXXXXXXXXXXXXXXXX
skey=XXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX
api_host=api-XXXXXXXX.duosecurity.com
radius_ip_1=5.6.7.8
radius_secret_1=radiussecret1
client=ad_client
port=1812
failmode=safe

Make sure to save your configuration file in your text editor — or validate and save in the Proxy Manager for Windows — when you're finished making changes.

Start the Proxy

net start DuoAuthProxy

authproxyctl start

net stop DuoAuthProxy & net start DuoAuthProxy

authproxyctl restart

# /opt/duoauthproxy/bin/authproxyctl start

# /opt/duoauthproxy/bin/authproxyctl status

# /opt/duoauthproxy/bin/authproxyctl restart

If you modify your authproxy.cfg configuration after initial setup, you'll need to stop and restart the Duo Authentication Proxy service or process for your change to take effect.

You can view information about your Authentication Proxy in the Authentication Proxy Dashboard.

Configure Your Array AG SSL VPN

Add the Duo RADIUS Server

1. Log in to the Array AG administrative interface. Change the mode from "Enable" to "Config".

2. Navigate to the Virtual Site that you'd like to protect using the drop-down list in the upper left corner.

3. Click on AAA under the "Site Configuration" menu on the left.

4. On the General tab, ensure that the Enable AAA option is checked, then click the Server tab. Once on the Server tab, click on RADIUS.

5. Enter a Server Name and Description for the new RADIUS server and click the Add button. Your new RADIUS server is added to the list. Double-click it to open the "Advanced RADIUS Server Configuration" page.

   

6. On the "Advanced RADIUS Server Configuration" page, click the Add RADIUS Server link in the lower right.

7. In the Add RADIUS Server form, enter the following information:

   Server IP	The IP address of your Duo RADIUS proxy
   Server Port	1812 (or whichever port specified in the Duo RADIUS proxy configuration)
   Secret Password	The RADIUS secret configured on your Duo RADIUS proxy
   Timeout	60
   Redundancy Order	1 if this is the first RADIUS server
   Retries	5
   Accounting Port	Default is 1813 (Accounting is not used so any port is fine)

   

   Click Save to save the RADIUS server settings. The new Duo RADIUS server is shown in the RADIUS SERVER CONFIGURATION list back on the "Advanced RADIUS Server Configuration" page.

8. Click on the Method tab then click Add Method on the right. Enter a Method Name and Method Description, then in the "General Authentication Configuration" section choose your Duo RADIUS AAA server from the Authentication drop-down list.

   

   Click Save to save the method configuration. The new method is shown in the list. While still on the Method tab, set the AAA Method for Mobile VPN Clients at the bottom to use the Duo RADIUS authentication method you just created.

   

9. Click on Web Access under the "Access Method" on the left, and then click the URL Property tab.

10. Click the Add URL Property link on the right. Leave the "Mask type" set as Rewrite and enter http://localhost/challenge/ as the "URL". Click the Save link on the right when done.

    

11. Click the Save Configuration link in the top right corner of the Array AG administrative interface, when prompted for confirmation click OK.

Upload the Custom Theme

1. While still logged in to the Array AG Config session, click on Portal under the "Site Configuration" menu on the left, then click the Themes tab.

2. Click Import Theme. Click the Choose File button and select the zipped theme file you downloaded earlier from Array's support portal. Enter a name for theme and click Import.

   

3. Double-click your newly created theme to get to the "THEME OBJECTS" page, and while on that page double-click the challenge theme object. This takes you to the "OBJECT RESOURCES" page.

4. Click the Edit link for the index.html file. Locate both occurrences of the string api-xxxxxxxx.duosecurity.com and replace it with the API host name shown on your Array application's properties page in the Duo Admin Panel.

   

   Click Save in the upper right corner when done. You are returned to the "THEME OBJECTS" page. Click the Back to top link to return to the "Themes" page.

5. Your new custom theme is in theme list, but is not the default theme. To make it the default theme, click your custom theme once to select it, then click Activate Theme in the upper right.

   

   Click OK in the activation confirmation pop-up. Your custom theme moves to the top of the list after activation.

   

6. Click the Save Configuration link in the top right corner of the Array AG administrative interface, when prompted for confirmation click OK.

Test Your Setup

To test your Array AG two-factor authentication setup, go to the URL that you defined for your sign-in policy. After you complete primary authentication, the Duo enrollment/login prompt appears.

Troubleshooting

Need some help? Review troubleshooting tips for the Authentication Proxy and try the connectivity tool included with Duo Authentication Proxy 2.9.0 and later to discover and troubleshoot general connectivity issues.

Also take a look at the Array AG Frequently Asked Questions (FAQ) page or try searching our Array AG Knowledge Base articles or Community discussions. For further assistance, contact Support.

Network Diagram

1. Primary authentication initiated to Array AG SSL VPN
2. Array AG SSL VPN send authentication request to Duo Security’s authentication proxy
3. Primary authentication using Active Directory or RADIUS
4. Duo authentication proxy connection established to Duo Security over TCP port 443
5. Secondary authentication via Duo Security’s service
6. Duo Authentication Proxy receives authentication response
7. Array AG SSL VPN access granted