Documentation
Two-Factor Authentication for CyberArk Privileged Account Security Solution
Last Updated: October 31st, 2024Contents
Duo helps secure your CyberArk Privileged Account Security Solution with two-factor authentication for Password Vault logins. In this type of configuration, users receive an automatic push or phone callback during login. Users who need to use a passcode may append it to their password when logging in.
If you have CyberArk Privileged Access v10 or later, try Duo Single Sign-on for CyberArk Privileged Access, which includes Duo Universal Prompt support.
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.
This application communicates with Duo's service on SSL TCP port 443.
Firewall configurations that restrict outbound access to Duo's service with rules using destination IP addresses or IP address ranges aren't recommended, since these may change over time to maintain our service's high availability. If your organization requires IP-based rules, please review Duo Knowledge Base article 1337.
Effective June 30, 2023, Duo no longer supports TLS 1.0 or 1.1 connections or insecure TLS/SSL cipher suites. See Duo Knowledge Base article 7546 for additional guidance.
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 2016 or later
- 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:
- Sign up for a Duo account.
- Log in to the Duo Admin Panel and navigate to Applications → Protect an Application.
- 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.
The security of your Duo application is tied to the security of your secret key (skey). Secure it as you would any sensitive credential. Don't share it with unauthorized individuals or email it to anyone under any circumstances!
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.
- Download the most recent Authentication Proxy for Windows from https://dl.duosecurity.com/duoauthproxy-latest.exe. Note that the actual filename will reflect the version e.g. duoauthproxy-6.4.2.exe. View checksums for Duo downloads here.
- Launch the Authentication Proxy installer on the target Windows server as a user with administrator rights and follow the on-screen prompts.
When installing, you can choose whether or not you want to install the Proxy Manager. The Proxy Manager is a Windows utility that helps you edit the Duo Authentication Proxy configuration, determine the proxy's status, and start or stop the proxy service. Learn more about using the Proxy Manager. Installing the Proxy Manager adds about 100 MB to the installed size.
If you do not want to install the Proxy Manager, you may deselect it on the "Choose Components" installer screen before clicking Install.
To perform a silent install on Windows, issue the following from an elevated command prompt after downloading the installer (replacing version with the actual version you downloaded):
duoauthproxy-version.exe /S
Append /exclude-auth-proxy-manager
to install silently without the Proxy Manager:
duoauthproxy-version.exe /S /exclude-auth-proxy-manager
Ensure you have compiler toolchain packages installed. On most recent RPM-based distributions — like Fedora, Red Hat Enterprise, and CentOS — you can install these by running (as root):
$ yum install gcc make libffi-devel zlib-devel diffutils
On Debian-derived systems, install these dependencies by running (as root):
$ apt-get install build-essential libffi-dev zlib1g-dev
If SELinux is present on your system and you want the Authentication Proxy installer to build and install its SELinux module, include
selinux-policy-devel
andchkconfig
in the dependencies:$ yum install gcc make libffi-devel zlib-devel diffutils selinux-policy-devel chkconfig
$ apt-get install build-essential libffi-dev zlib1g-dev selinux-policy-devel chkconfig
-
Download the most recent Authentication Proxy for Unix from https://dl.duosecurity.com/duoauthproxy-latest-src.tgz. From the command line you can use
curl
orwget
to download the file, like$ wget --content-disposition https://dl.duosecurity.com/duoauthproxy-latest-src.tgz
. Depending on your download method, the actual filename may reflect the version e.g. duoauthproxy-6.4.2-src.tgz. View checksums for Duo downloads here. Extract the Authentication Proxy files and build it as follows:
$ tar xzf duoauthproxy-6.4.2-src.tgz $ cd duoauthproxy-version-src $ make
-
Install the authentication proxy (as root):
$ cd duoauthproxy-build $ ./install
Follow the prompts to complete the installation. The installer creates a user to run the proxy service and a group to own the log directory and files. You can accept the default user and group names or enter your own.
If SELinux is present on the target server, the Duo installer will ask you if you want to install the Authentication Proxy SELinux module. Your selection affects whether systemd can start the Authentication Proxy after installation.
SELinux Mode Default Response Result Enforcing Yes Choose 'yes' to install the Authentication Proxy's SELinux module. This permits start of the Authentication Proxy service by systemd. If you choose 'no' then the SELinux module is not installed, and systemd cannot start the Authentication Proxy service. Permissive No Choose 'no' to decline install of the Authentication Proxy's SELinux module. The Authentication Proxy service can be started by systemd. However, if you change SELinux from permissive to enforcing mode after installing the Duo proxy, systemd can no longer start the Authentication Proxy service. If you plan to enable SELinux enforcing mode later, you should choose 'yes' to install the Authentication Proxy SELinux module now. If you choose to install the Authentication Proxy SELinux module and the dependencies
selinux-policy-devel
andchkconfig
are not present, then the installer fails to build the module.The proxy listens for LDAP connections on ports 389 and 636 by default. Privileged ports below 1024 are reserved for the root user. Therefore, the proxy will not start if you choose any user account other than "root" to run under during installation.
To install the Duo proxy silently with the default options, use the following command:
sudo ./duoauthproxy-build/install --install-dir /opt/duoauthproxy --service-user duo_authproxy_svc --log-group duo_authproxy_grp --create-init-script yes
Append --enable-selinux=yes|no
to the install command to choose whether to install the Authentication Proxy SELinux module.
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:
Operating System | Authentication Proxy Version |
Path |
---|---|---|
Windows | v5.0.0 and later | C:\Program Files\Duo Security Authentication Proxy\conf\authproxy.cfg |
Windows | v4.0.2 and earlier | C:\Program Files (x86)\Duo Security Authentication Proxy\conf\authproxy.cfg |
Linux | All | /opt/duoauthproxy/conf/authproxy.cfg |
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
host
|
The hostname or IP address of your domain controller or directory server. If this host doesn't respond to a primary authentication request and no additional hosts are specified (as |
service_account_username
|
The username of a domain account that has permission to bind to your directory and perform searches. We recommend creating a service account that has read-only access. This parameter not required when using SSPI authentication; see the |
service_account_password
|
The password corresponding to This parameter not required when using SSPI authentication; see the |
search_dn
|
The LDAP distinguished name (DN) of an Active Directory/LDAP container or organizational unit (OU) containing all of the users you wish to permit to log in. For example:
|
Optional
host_2
|
The hostname or IP address of a secondary/fallback domain controller or directory server, which the Authentication Proxy will use if a primary authentication request to the system defined as |
security_group_dn
|
To further restrict access, specify the LDAP distinguished name (DN) of a security group that contains the users who should be able to log in as direct group members. Nested groups are not supported. Users who are not direct members of the specified group will not pass primary authentication. Example:
Starting with Authentication Proxy v3.2.0, the |
username_attribute
|
LDAP attribute found on a user entry which will contain the submitted username. In most Active Directory configurations, it should not be necessary to change this option from the default value. OpenLDAP directories may use "uid" or another attribute for the username, which should be specified with this option. Default: "sAMAccountName" |
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
api_host
|
Your API hostname (i.e. api-XXXXXXXX.duosecurity.com) | ||||||
ikey
|
Your integration key | ||||||
skey
|
Your secret key | ||||||
client
|
The mechanism that the Authentication Proxy should use to perform primary authentication. This should correspond with a "client" section elsewhere in the config file.
This parameter is optional if you only have one "ad_client" section. If you have multiple, each "server" section should specify which "client" to use. |
||||||
failmode
|
Either safe or secure:
|
||||||
ssl_cert_path
|
(Optional) Path to PEM-formatted SSL/TLS server certificate. Both ssl_key_path and ssl_cert_path must be specified to listen for STARTTLS or LDAPS requests. |
||||||
ssl_key_path
|
(Optional) Path to PEM-formatted SSL/TLS private key. Both ssl_key_path and ssl_cert_path must be specified to listen for STARTTLS or LDAPS requests. |
||||||
exempt_ou_1
|
Specify the DN of the service account used to authenticate from CyberArk Privileged Account Security Solution to the Authentication Proxy (the account configured as the BindUserName for the LDAP directory in CyberArk). Multi-factor authentication is not required for this user. This setting is needed because CyberArk Privileged Account Security Solution first connects to the Authentication Proxy as the service account user, disconnects, and then authenticates the user who is logging in with a separate LDAP connection. All other accounts will require Duo authentication. |
||||||
exempt_primary_bind
|
Set this value to 'false'. This setting, when combined with the exempt_ou_1 setting above, ensures that the CyberArk Privileged Account Security Solution service account's initial bind to the Authentication Proxy does not require two-factor authentication, but all other account logins via LDAP do. |
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.
View video guides for proxy deployment at the Authentication Proxy Overview or see the Authentication Proxy Reference for additional configuration options.
Start the Proxy
If you installed the Duo Authentication Proxy Manager utility (available with 5.6.0 and later), click the Start Service button at the top of the Proxy Manager window to start the service.
To start the service from the command line, open an Administrator command prompt and run:
net start DuoAuthProxy
Alternatively, open the Windows Services console (services.msc
), locate "Duo Security Authentication Proxy Service" in the list of services, and click the Start Service button.
Authentication Proxy v5.1.0 and later includes the authproxyctl
executable, which shows the connectivity tool output when starting the service. The installer adds the Authentication Proxy C:\Program Files\Duo Security Authentication Proxy\bin
to your system path automatically, so you should not need to specify the full path to authproxyctl
to run it.
From an administrator command prompt run:
authproxyctl start
If the service starts successfully, Authentication Proxy service output is written to the authproxy.log file, which can be found in the log
subdirectory.
If you see an error saying that the "service could not be started", open the Application Event Viewer and look for an Error from the source "DuoAuthProxy". The traceback may include a "ConfigError" that can help you find the source of the issue.
Stop and restart the Authentication Proxy service by either clicking the Restart Service button in the Duo Authentication Proxy Manager or the Windows Services console or issuing these commands from an Administrator command prompt:
net stop DuoAuthProxy & net start DuoAuthProxy
To stop and restart the Authentication Proxy using authproxyctl, from an administrator command prompt run:
authproxyctl restart
Open a root shell and run:
# /opt/duoauthproxy/bin/authproxyctl start
To ensure the proxy started successfully, run:
# /opt/duoauthproxy/bin/authproxyctl status
Authentication Proxy service output is written to the authproxy.log file, which can be found in the log
subdirectory.
To stop and restart the Authentication Proxy, open a root shell and run:
# /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 the LDAP Directory in CyberArk Privileged Account Security Solution
Configure Password Vault Web Access
-
Log on to Password Vault Web Access via your browser as the predefined Administrator user. This is typically accessed at https://yourvaultserver/PasswordVault.
-
Click on ADMINISTRATION at the top to navigate to the "System Configuration" page. Then, click on LDAP Integration in the "Component Settings" table.
-
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 theexempt_ou_1
value you configured in theldap_server_auto
section of your Duo proxy server'sauthproxy.cfg
file earlier . -
Go to LDAP → Directories → the AD directory currently used for Privileged Account Security access → Hosts. Right-click Hosts and select Add Host.
-
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.
-
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.
-
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:
push |
Perform Duo Push authentication You can use Duo Push if you've installed Duo Mobile and added your account to it |
phone | Perform phone callback authentication |
sms |
Send a new batch of SMS passcodes Your initial authentication attempt is rejected and you'll receive a text message with Duo passcodes. You can then try to log on again, authenticating with one of the newly-delivered passcodes. |
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
- Primary authentication initiated to CyberArk Privileged Account Security
- CyberArk Privileged Account Security sends authentication request to Duo Security’s authentication proxy
- Primary authentication using Active Directory
- Duo authentication proxy connection established to Duo Security over TCP port 443
- Secondary authentication via Duo Security’s service
- Duo Authentication Proxy receives authentication response
- CyberArk Privileged Account Security access granted