Two-Factor Authentication for CyberArk Privileged Account Security Solution

These instructions assume that you already have Active Directory authentication working with CyberArk Privileged Account Security Solution. Use Duo's LDAP proxy with CyberArk instead of RADIUS when you want to continue using LDAP group lookup to assign privileges in CyberArk Privileged Account Security.

Overview

To integrate Duo with your CyberArk Privileged Account Security Solution environment, you will need to install a local proxy service on a machine within your network. This Duo proxy will accept incoming ldap connections from the downstream application, perform primary authentication against an upstream LDAP directory server, and then add Duo secondary authentication.

If you are already running a Duo Authentication Proxy server in your environment, you can generally use that existing host for additional applications, appending the new configuration sections to the current config.

Once configured, Duo sends your users an automatic authentication request via Duo Push notification to a mobile device or phone call after successful primary login.

This configuration doesn't support inline self-service enrollment. You'll need to create your users in Duo ahead of time using one of our other enrollment methods, like directory sync or CSV import. Read the enrollment documentation to learn more.

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 LDAP authentication configuration for your CyberArk Privileged Account Security Solution environment users before you begin to deploy Duo.

To integrate Duo with your CyberArk Privileged Account Security Solution environment, you will need to install a local Duo proxy service on a machine within your network. This Duo proxy server will receive incoming LDAP requests from your CyberArk Privileged Account Security Solution environment, contact your existing local LDAP/AD 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.

If you will set up a new Duo server, locate (or set up) a system to host the Duo Authentication Proxy installation. The proxy supports these operating systems:

• Windows Server 2012 or later (Server 2016 or 2019 recommended)
• CentOS 7 or later
• Red Hat Enterprise Linux 7 or later
• Ubuntu 16.04 or later
• Debian 7 or later.

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 CyberArk Privileged Account Security LDAP/RADIUS 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.

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. The primary authentication source for Duo LDAP must be another LDAP directory. In most cases, this means configuring the Proxy to communicate with Active Directory.

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.

Configure the Proxy As a LDAP Server

Next, you need to set up the Authentication Proxy to handle LDAP authentication requests. Create an [ldap_server_auto] section and add the properties listed below. If you've already set up the Duo Authentication Proxy for a different LDAP application, append a number to the section header to make it unique, like [ldap_server_auto2].

Required

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=ServiceAcct  
service_account_password=Password1  
search_dn=cn=Users,dc=example,dc=com  

[ldap_server_auto]
ikey=DIXXXXXXXXXXXXXXXXXX
skey=XXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX
api_host=api-XXXXXXXX.duosecurity.com
failmode=safe  
ssl_key_path=ldap_server.key  
ssl_cert_path=ldap_server.pem
exempt_primary_bind=false
exempt_ou_1=CN=ServiceAcct,CN=users,DC=example,DC=com

Make sure to save your configuration file when done.

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.

Configure the LDAP Directory in CyberArk Privileged Account Security Solution

Configure Password Vault Web Access

1. Log on to Password Vault Web Access via your browser as the predefined Administrator user. This is typically accessed at https://yourvaultserver/PasswordVault.

2. Click on ADMINISTRATION at the top to navigate to the "System Configuration" page. Then, click on LDAP Integration in the "Component Settings" table.

3. Go to LDAP → Directories → the AD directory currently used for Privileged Account Security access. Verify that the BindUserName is set to the full DN of the service account user (e.g. CN=ServiceAcct,CN=users,DC=example,DC=com) and that it matches the exempt_ou_1 value you configured in the ldap_server_auto section of your Duo proxy server's authproxy.cfg file earlier .

4. Go to LDAP → Directories → the AD directory currently used for Privileged Account Security access → Hosts. Right-click Hosts and select Add Host.

5. In the Properties table, the required information about the Duo LDAP proxy host (example shows adding Duo Authentication Proxy host to the "Duo LDAP" existing directory with the IP 10.1.10.101 using LDAP/389):

   ServerName	The IP address or fully-qualified DNS host name of your Duo Authentication Proxy server.
   ServerPort	Duo Authentication Proxy server port for incoming LDAP requests. Default port is '389' for CLEAR and STARTTLS and '636' for LDAPS. If using STARTTLS or LDAPS then the ssl_cert_path and ssl_key_path options must be configured in the Authentication Proxy LDAP configuration above.
   SSLConnect	Select No for LDAP or Yes for LDAPS and STARTTLS.

6. Right-click the new Duo LDAP Proxy host in the "Hosts" tree and select Move Up. Repeat until the Duo host is the first one in the list.

7. Click Apply in the upper left, and then click OK.

   

For additional information please refer to the "LDAP Authentication" section in the "CyberArk Privileged Account Security Installation Guide".

Test Your Setup

Navigate to the Privileged Account Security web login page and click the LDAP directory option to which you added the Duo LDAP proxy host.

Enter your Active Directory username and password. When you enter your username and password, you will receive an automatic push or phone callback. Alternatively you can add a comma (",") to the end of your password, followed by a Duo passcode.

For example, given a username 'bob', with password 'password123' and a Duo passcode '123456', you would enter:

username: bob
password: password123,123456

In addition, you may also enter the name of an out-of-band factor in lieu of a passcode. You may choose from the following factor names:

Returning to the previous example, if you wanted to use Duo Push (rather than a passcode) to authenticate, you would enter:

username: bob
password: password123,push

You can also specify a number after the factor name if you have more than one device enrolled. So you can enter phone2 or push2 if you have two phones enrolled and you want the Duo Push or phone call request to go to your second phone instead.

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 our CyberArk Knowledge Base articles or Community discussions. For further assistance, contact Support.

Next Steps

To further secure access to the CyberArk Privileged Account Security Solution, you can remove any LDAP hosts that aren't Duo LDAP proxy hosts or disable alternate authentication methods. See the "Authenticating to the Privileged Account Security Solution" section in the "CyberArk Privileged Account Security Installation Guide" for guidance.

Network Diagram

1. Primary authentication initiated to CyberArk Privileged Account Security
2. CyberArk Privileged Account Security sends authentication request to Duo Security’s authentication proxy
3. Primary authentication using Active Directory
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. CyberArk Privileged Account Security access granted