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Two-Factor Authentication for CyberArk Privileged Account Security

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're using LDAP group lookup to assign privileges in CyberArk Privileged Account Security and want to preserve this behavior, we recommend using Duo's LDAP proxy with CyberArk instead of RADIUS.

First Steps

To integrate Duo with your CyberArk Privileged Account Security Solution, you will need to install a local proxy service on a machine within your network. Before proceeding, you should locate (or set up) a system on which you will install the Duo Authentication Proxy. The proxy supports Windows and Linux systems (in particular, we recommend Windows Server 2012 R2 or later, Red Hat Enterprise Linux 6 or later, CentOS 6 or later, or Debian 6 or later).

This Duo proxy server also acts as a RADIUS server — there's no need to deploy a separate RADIUS server to use Duo.

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 in the applications list. Click Protect this Application to get your integration key, secret key, and API hostname. See Getting Started for help.

Install the Duo Authentication 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).

  1. 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-2.4.19.exe.
  2. Launch the Authentication Proxy installer on the target Windows server as a user with administrator rights and follow the on-screen prompts.
  1. Ensure that OpenSSL, Python 2.6 or 2.7 (including development headers and libraries), and a compiler toolchain are installed. On most recent RPM-based distributions — like Fedora, RedHat Enterprise, and CentOS — you can install these by running (as root):

    $ yum install gcc make openssl-devel python-devel libffi-devel

    On Debian-derived systems, install these dependencies by running (as root):

    $ apt-get install build-essential libssl-dev python-dev libffi-dev

    To ensure that your Python version will work with the Authentication Proxy, run:

    $ python --version

    If the output does not say "Python 2.6.x" or "Python 2.7.x", first take note that many distributions can support multiple versions of python simultaneously. If your python installation does not appear to be a supported version, try replacing "python" in the above command with "python2.6" or "python2.7". If neither of these work, then you will need to install a different version of Python. You may need to search additional repositories for your distribution (e.g. for Centos or Red Hat Enterprise Linux, Extra Packages for Enterprise Linux), or build Python from source.

  2. Download the most recent Authentication Proxy for Unix from https://dl.duosecurity.com/duoauthproxy-latest-src.tgz. Depending on your download method, the actual filename may reflect the version e.g. duoauthproxy-2.4.19-src.tgz.

  3. Extract the Authentication Proxy files and build it as follows:

    $ tar xzf duoauthproxy-latest-src.tgz
    $ cd duoauthproxy-version-src
    $ export PYTHON=python_command
    $ make
    Where python_command is the command to run a Python 2.6 or Python 2.7 interpreter (e.g. "python", "python2.6", "python2.7").
  4. Install the authentication proxy (as root):

    $ cd duoauthproxy-build
    $ ./install

    Follow the prompts to complete the installation.

If you ever need to uninstall the proxy, run /opt/duoauthproxy/uninstall.

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:

Platform Default Configuration Path
Windows (64-bit) C:\Program Files (x86)\Duo Security Authentication Proxy\conf\authproxy.cfg
Windows (32-bit) C:\Program Files\Duo Security Authentication Proxy\conf\authproxy.cfg
Linux /opt/duoauthproxy/conf/authproxy.cfg

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. 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. In most cases, this means configuring the Proxy to communicate with Active Directory or RADIUS.

Active Directory

To use Active Directory as your primary authenticator, add an [ad_client] section to the top of your config file. Add the following properties to the section:

Required

host The hostname or IP address of your domain controller.
service_account_username The username of a domain member account that has permission to bind to your Active Directory and perform searches. We recommend creating a service account that has read-only access.
service_account_password The password corresponding to service_account_username. If you're on Windows and would like to encrypt this password, see Encrypting Passwords in the full Authentication Proxy documentation.
search_dn

The LDAP distinguished name (DN) of an Active Directory container or organizational unit (OU) containing all of the users you wish to permit to log in. For example:

search_dn=DC=example,DC=com

Optional

host_2 The hostname or IP address of a secondary/fallback domain controller. You can add additional domain controllers as host_3, host_4, etc.
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. Other users will not pass primary authentication. For example:

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

host The IP address of your RADIUS server. You can add backup servers with host_2, host_3, etc.
secret A secret to be shared between the Authentication Proxy and your existing RADIUS server. If you're on Windows and would like to encrypt this secret, see Encrypting Passwords in the full Authentication Proxy documentation.

Optional

port The authentication port on your RADIUS server. By default, the proxy will attempt to contact your RADIUS server on port 1812. Use port_2, port_3, etc. to specify ports for the backup servers.
pass_through_all If this option is set to "true", all RADIUS attributes set by the primary authentication server will be copied into RADIUS responses sent by the proxy. Default: "false"

For example:

[radius_client]
host=1.2.3.4
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 CyberArk Privileged Account Security Solution

Next, we'll set up the Authentication Proxy to work with your CyberArk Privileged Account Security Solution. Create a [radius_server_auto] section with the following properties:

Required

ikey Your integration key.
skey Your secret key.
api_host Your API hostname (e.g. "api-XXXXXXXX.duosecurity.com").
radius_ip_1 The IP address of your CyberArk Privileged Account Security Solution.
radius_secret_1

A secret to be shared between the proxy and your CyberArk Privileged Account Security Solution. The secret length may not exceed 16 characters.

If you're on Windows and would like to encrypt this secret, see Encrypting Passwords in the full Authentication Proxy documentation.

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.

"ad_client" Use Active Directory for primary authentication. Make sure you have an [ad_client] section configured.
"radius_client" Use RADIUS for primary authentication. Make sure you have a [radius_client] section configured.
"duo_only_client" Do not perform primary authentication. Make sure you have a [duo_only_client] section configured.

This parameter is optional if you only have one "client" section. If you have multiple, each "server" section should specify which "client" to use.

Optional

port The port on which to listen for incoming RADIUS Access Requests. Default: 1812.
failmode

Either "safe" or "secure":

"safe" In the event that Duo's service cannot be contacted, users' authentication attempts will be permitted if primary authentication succeeds. This is the default.
"secure" In the event that Duo's service cannot be contacted, all users' authentication attempts will be rejected.
radius_ip_2 The IP address of your second CyberArk Privileged Account Security Solution, if you have one. You can specify additional devices as as radius_ip_3, radius_ip_4, etc.
radius_secret_2

The secrets shared with your second CyberArk Privileged Account Security Solution, if using one. You can specify secrets for additional devices as radius_secret_3, radius_secret_4, etc. The secret length may not exceed 16 characters.

If you're on Windows and would like to encrypt this secret, see Encrypting Passwords in the full Authentication Proxy documentation.

A completed config file that uses Active Directory 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_auto]
ikey=DIXXXXXXXXXXXXXXXXXX
skey=XXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX
api_host=api-XXXXXXXX.duosecurity.com
radius_secret_1=radiussecret1
client=ad_client
port=1812
failmode=safe

Make sure to save your configuration file when done.

Note

View video guides for proxy deployment at the Authentication Proxy Overview or see the Authentication Proxy Reference Guide for additional configuration options.

Start the Proxy

Open an Administrator command prompt and run:

net start DuoAuthProxy

Alternatvely, open the Windows Services console (services.msc), locate "Duo Security Authentication Proxy Service" in the list of services, and click the Start Service button.

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 Windows Services console or issuing these commands from an Administrator command prompt:

net stop DuoAuthProxy & net start DuoAuthProxy

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

Configure CyberArk Privileged Account Security

Define the Duo RADIUS Authentication Method

  1. Log on to your Vault server and open an command prompt window. The command utilities for configuring RADIUS are in the Vault installation folder, typically the C:\Program Files (x86)\PrivateArk\Server directory. Your Vault install directory may differ.

  2. (Optional) Obtain a Vault certificate and private key from a Certificate Authority and install on your Vault machine if one is not already present. CyberArk recommends not using a self-signed certificate for RADIUS authentication.

    If you do not already have a Vault certificate and private key, use the CACert.exe utility to generate the request.

    This example command creates a certificate request file called VaultCert.req for the Vault's DNS hostname vault.acme.local with the Vault's IP address 10.1.10.110 as the subject alternate name and additional identifying information about the organization requesting the certificate:

    CACert request /reqoutfile c:\temp\VaultCert.req /country "US" /locality "Ann Arbor" /org "Acme Corp" /orgunit "IT" /commonname "vault.acme.local" /subjalt "IP:10.1.10.110"

    Submit this request to your Certificate Authority to obtain a certificate for the Vault server. Once you have the certificate, copy it to your Vault server and install it in the Vault with the CACert utility. In this example command, the new certificate name is cyberarkvault.cer:

    CACert install /CertFileName c:\temp\cyberarkvault.cer

    To see the full requirements for Vault certificates and a detailed description of this step see "Configuring RADIUS Authentication" Step 1 in the the "CyberArk Privileged Account Security Installation Guide". For more information about the CACert command and its options refer to Appendix B of the "Privileged Account Security Installation Guide".

  3. On the Vault server, launch the PrivateArk Server application. Use Server Central Administration to stop the Vault.

  4. Create an encrypted file containing the same RADIUS secret specified in your Duo authproxy.cfg with the CAVaultManager command. This example outputs the secret radiussecret1 to the file radiusauth.dat.

    CAVaultManager SecureSecretFiles /SecretType Radius /Secret radiussecret1 /SecuredFileName radiusauth.dat
    
    ITADB399I Using encryption algorithms: Advanced Encryption Standard (AES), 256 bit,
    RSA (2048 bit), SHA2-512 (Protocol Integrity), SHA2-512 (Files Integrity).
    CAVLT044I RADIUS secret was secured successfully.
  5. Make a backup copy of the DBParm.ini file in your Vault Server installation directory, and then open it in a text editor.

  6. Add a new RadiusServersInfo line that specifies, in order, the IP address of your Duo Authentication Proxy server, the port specified in your [radius_server_auto] section of the authproxy.cfg file, the hostname of your Vault server, and the name of the encrypted RADIUS secret file created with the CAVaultManager command in step 4.

    RadiusServersInfo=10.1.10.101;1812;vault.acme.local;radiusauth.dat
  7. Return to the PrivateArk Server Server Central Administration window to restart the Vault server.

See "Configuring RADIUS Authentication" steps 2 through 5 in the "CyberArk Privileged Account Security Installation Guide" for additional details and options.

Configure User Accounts for RADIUS

Update the authentication method for any users who you want to log in with Duo.

  1. Launch the PrivateArk Client application. Double-click the Server Vault to logon as the predefined Administrator user.

  2. Go to ToolsAdministrative ToolsUsers and Groups.

  3. Click on the user you want to switch to Duo RADIUS authentication, then click the Update button to show the user's properties.

  4. Click the Authentication tab and select RADIUS Authentication from the Authentication method drop-down list. Click OK.

    CyberArk User Authentication Method

  5. Log off the Vault.

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 Options in the "Component Settings" table.

  3. Scroll down the listed configuration items on the left to Authentication Methods. Expand this to show a list of configuration methods and click on radius.

  4. In the Properties table, enter a descriptive DisplayName, like "Duo RADIUS", and set Enabled to Yes.

  5. Click Apply in the lower right, and then click OK.

    CyberArk RADIUS Authentication Method

For additional information about adding Duo RADIUS authentication to please refer to the "CyberArk PVWA Integration with Duo - Implementation Guide" published by CyberArk, as well as the "RADIUS 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 new Duo RADIUS option (this name matches the "DisplayName" you specified when configuring the RADIUS authentication method).

CyberArk RADIUS Logon

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? 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 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

CyberArk Privileged Account Security RADIUS 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 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. CyberArk Privileged Account Security access granted

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