Duo integrates with your F5 BIG-IP APM to add two-factor authentication to any VPN login, complete with inline self-service enrollment and authentication prompt. Check out F5 FirePass SSL VPN if you don't have a BIG-IP APM.
The Duo F5 Big-IP configuration with inline enrollment and authentication prompt supports firmware versions 11.4 - 11.6 and 12.0.
Refer to our alternate instructions if you want to configure Duo on your BIG-IP with automatic push and phone call authentication.
To integrate Duo with your F5 BIG-IP APM, 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:
This integration communicates with Duo's service on TCP port 443. Also, we do not recommend locking down your firewall to individual IP addresses, since these may change over time to maintain our service's high availability.
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).
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.
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.
Extract the Authentication Proxy files and build it as follows:
Where python_command is the command to run a Python 2.6 or Python 2.7 interpreter (e.g. "python", "python2.6", "python2.7").
$ tar xzf duoauthproxy-latest-src.tgz $ cd duoauthproxy-version-src $ export PYTHON=python_command $ make
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
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|
The configuration file is formatted as a simple INI file. Section headings appear as:
Individual properties beneath a section appear as:
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.
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.
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:
||The hostname or IP address of your domain controller.|
||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.|
The password corresponding to
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:
The hostname or IP address of a secondary/fallback domain controller. You can add additional domain controllers as
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:
[ad_client] host=188.8.131.52 host_2=184.108.40.206 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.
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:
The IP address of your RADIUS server. You can add backup servers with
||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.|
The authentication port on your RADIUS server. By default, the proxy will attempt to contact your RADIUS server on port 1812. Use
||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"|
[radius_client] host=220.127.116.11 secret=thisisaradiussecret
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.
Next, we'll set up the Authentication Proxy to work with your F5 BIG-IP APM. Create a
[radius_server_iframe] section with the following properties:
||Your integration key.|
||Your secret key.|
||Your API hostname (e.g. "api-XXXXXXXX.duosecurity.com").|
||The IP address of your F5 BIG-IP APM.|
||A secret to be shared between the proxy and your F5 BIG-IP APM. If you're on Windows and would like to encrypt this secret, see Encrypting Passwords in the full Authentication Proxy documentation.|
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 "client" section. If you have multiple, each "server" section should specify which "client" to use.
||The port on which to listen for incoming RADIUS Access Requests. Default: 1812.|
Either "safe" or "secure":
The IP address of your second F5 BIG-IP APM, if you have one. You can specify additional devices as as
The secrets shared with your second F5 BIG-IP APM, if using one. You can specify secrets for additional devices as
A completed config file, using Active Directory as the primary authenticator, should look something like:
[ad_client] host=18.104.22.168 service_account_username=duoservice service_account_password=password1 search_dn=cn=Users,dc=example,dc=com [radius_server_iframe] type=f5_bigip ikey=DIXXXXXXXXXXXXXXXXXX skey=XXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX api_host=api-XXXXXXXX.duosecurity.com radius_ip_1=22.214.171.124 radius_secret_1=thisisalsoaradiussecret client=ad_client port=1812 failmode=safe
Make sure to save your configuration file when done.
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
Log into the BIG-IP management console and navigate to Access Policy → AAA Servers → RADIUS and click the Create button.
Enter a name for your new Duo RADIUS server. Set the Mode to "Authentication" and fill in the host/port/secret information that corresponds to your Duo Authentication Proxy configuration. Be sure to increase the timeout to 60 seconds.
You'll need to modify an existing Access Policy to use the newly defined Duo RADIUS server for authentication (or create a new one). Navigate to Access Policy → Access Profiles → Access Profiles List and click the Edit... link in the Access Policy column of the profile you want to update to use Duo.
Use the Access Policy editor to replace your current authentication method (like AD Sync) with RADIUS. Click the plus symbol and type "RADIUS" in the search field on the subsequent page. Select RADIUS Auth and click Add Item.
On the RADIUS Auth properties tab select your Duo RADIUS system in the AAA Server drop-down and cick Save.
Your policy probably now shows two authenticators (RADIUS and your original method). Click the "X" on your former authentication method to remove it.
In this example, the Duo RADIUS authentication has been added to an existing Access Policy after the primary Logon page.
Click Close to exit the Access Policy editor and return to the Access Profile List page. The profile you just modified may have a yellow status flag. Click the checkbox next to that policy to select it and then click Apply Access Policy. The status flag will turn green.
Consult the BIG-IP Access Policy Manager Configuration Guide for more information about creating and modifying Access Policies or contact F5 support.
Navigate to Access Policy → Customization → Advanced and change the "Edit Mode" to Advanced. Navigate through the Access Profiles tree to the Common folder beneath your Access Policy.
Add the Duo script, using the instructions for your BIG-IP firmware version:
v11.5 and greater only: While still in Access Policy Advanced Customization Editor, navigate through the Access Profiles tree to Access Policy > Logon Pages > Logon Page folder beneath your Access Policy.
Click the logon.inc item and locate the following line in the Advanced Customization Editor (around line 500):
<td colspan=2 id="credentials_table_header"></td>
Edit that line with the additional tag shown below and click Save:
<td colspan=2 id="credentials_table_header"><? echo $formHeader; ?></td>
Save the customization changes and return to the Access Profile List page. The profile you just modified may have a yellow status flag. Click the checkbox next to that policy to select it and then click Apply Access Policy. The status flag will turn green.
For F5 BIG-IP versions prior to 11.4, you may need to navigate to the "Customization" tab of your Access Policy, select customization type of "general UI" and click "Find Customization" to make the footer edit. Insert the JS snippet at the end of the "Footer text" input box and click "Update."
To test your setup, go to the URL you normally use to log in to your F5 BIG-IP APM. After you complete the primary authentication, Duo enrollment/login should appear.