Tag Archives: push

Adding Duo 2FA to Microsoft ADFS

Posted on by
2

KB ID 0001656

Problem

I did a Duo run through a few weeks ago, and to be honest their documentation is usually pretty good. I was spinning this up as a PoC for a client so I thought I’d put my take on the procedure here.

ADFS Duo Pre-Requisites

I already have a Duo Authentication Proxy server setup and my users are enrolled, you will need to set this up first. See the following article;

Duo: ADSync and Enroll Users via SMS

Log into the the Duo Admin Portal > Applications > Protect an Application > Search for and select Microsoft ADFS > Protect This Application.

 Copy the Integration Key, Secret Key and the API hostname to notepad.

Download the Duo AD FA MFA Adapter on your ‘first‘ ADFS server. Enter the information you copied to Notepad, (above). Tick ‘Bypass Duo Authentication when offline’, and because my users are logging on with their Office 365 UPNs, I’m also ticking ‘Use UPN username format’ (SEE USERNAME NORMALISATION NOTE BELOW.)

Note: I only have one ADFS server, if you have an ADFS Server farm you will need to install each one with the SAME shared session key, you can generate one of these yourself in PowerShell with the following commands;

[box]

$bytes = new-object "System.Byte[]" 30
(new-object System.Security.Cryptography.RNGCryptoServiceProvider).GetBytes($bytes)
[Convert]::ToBase64String($bytes)

[/box]

I only have one, so I’ll simply ‘Generate new session key‘ > Finish the install wizard.

Note: If one has already been deployed, and you don’t know the key, go to the ADFS server on which it’s working, and look in the following registry key.

[box]

HKEY_LOCAL_MACHINE\SOFTWARE\Duo Security\DuoAdfs\AKey

[/box]

USERNAME NORMALISATION: Because I’m logging users on with UPNs (first-name.last-name.domain-name.com) Back in the Duo Portal under protected applications Microsoft ADFS > Set username normalisation to ‘None” > Scroll down and save the change.

Server 2019 Only: I’m deploying on Server 2019 so I also need to execute the following Powershell command, you will need to enter YOUR API Hostname (you copied above).

[box]

Set-AdfsResponseHeaders -SetHeaderName "Content-Security-Policy" -SetHeaderValue "default-src 'self' 'unsafe-inline' 'unsafe-eval'; img-src 'self'; frame-src api-xxxxxxxx.duosecurity.com"

[/box]

Launch the ADFS Management Console > Authentication Methods > Additional Authentication Methods > Edit.

Tick ‘Duo Authentication for AD FS {version}’ > Apply > OK.

Relying Party Trust > Here I have my Office 365 trust, yours may be for something else! Edit Access Control Policy.

Click ‘Use Access Control Policy’ > The one I want is ‘Permit Everyone and Require MFA for Specific Group‘. This way I can select who gets 2FA challenged, and I can migrate users slowly into this group once I know they are enrolled, (also I use the same group to Sync the users to Duo to make things simple). Change the <parameter> and locate you domain security group.

Now when the users connect to ADFS, after they logon, they are challenged to provide 2FA authentication.

like so;

Related Articles, References, Credits, or External Links

NA

AnyConnect: Enable Duo 2Factor Authentication

Posted on by
5

KB ID 0001650

Problem

I was asked if I’d ever set this up the other week. Surprisingly I had not, I’d deployed Duo for other things, but not for Cisco AnyConnect. As I had some other ‘Duo’ related tasks coming up, I was deploying it on the test bench, then adding in my Cisco ASA and AnyConnect wasn’t much more work!

Here’s my topology;

  • My ASA is running version 9.1
  • My Duo Authentication Proxy is installed on Windows 2019
  • I’m running Cisco AnyConnect Version 4.8

Cisco AnyConnect Duo Pre-Requisites

I already have a Duo Authentication Proxy server setup and my users are enrolled, you will need to set this up first. See the following article;

Duo: ADSync and Enroll Users via SMS

Also I’m using LDAPS, if you have not set that up (it’s easy) then see the following article;

Get Ready for LDAPS Channel Binding

I would also setup AnyConnect and have it working with LOCAL authentication before migrating to Duo/2FA Authentication;

Cisco ASA 5500 AnyConnect Setup From Command Line

Duo: Deploy Cisco RADIUS VPN

Log into the the Duo Admin Portal > Applications > Protect an Application > Search for and select Cisco RADIUS VPN > Copy the Integration Key, Secret Key and the API hostname to notepad.

Back on your Duo Authentication Proxy, (because you completed the pre-requisites) add the following to the bottom of your authproxy.cfg file;

[box]

[radius_server_auto]
ikey=XXXXXXXXXXXXXXXXXXXX
skey=XXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX
api_host=XXXXXXXXXXXXXXXXXXXXXXXXXXXX
radius_ip_1=192.168.254.254
radius_secret_1=666999
client=ad_client
port=1812
failmode=safe

[/box]

Note: 192.168.254.254 is the inside interface of the Cisco ASA, and 666999 is the shared secret we will enter on the firewall in a moment. I’m not sure you have to, but at this point I’d restart the Duo Auth Proxy service as well.

Configure Cisco ASA for Duo RADIUS

Log into the ASDM > Configuration > Device Management > Users/AAA > AAA Server Groups > Add.

You only need to add the name of the server group i.e DUO-RADIUS, and ensure protocol is set to RADIUS > OK > Apply.

Now select the DUO-RADIUS group in the top window, and click ‘Add’ in the bottom window > Specify the interface that’s facing the Duo Auth Proxy Server > Add its IP address > Change the Timeout to 60 seconds > Set the Server Authentication port to 1812 > Set the Server Accounting Port to 1813, (though it will NOT do accounting) > Type in the Secret Key you specified above > Untick Microsoft CHAPv2 Capable > OK.

Testing Cisco ASA Duo 2FA Authentication

I’ve written about testing AAA before in the following article;

Cisco – Testing AAA Authentication (Cisco ASA and IOS)

But essentially with the SERVER selected > Test > Select Authentication > Enter the username and password for a user.

What about passcodes and 2FA? This will send a push notification to the users Duo Authenticator (phone), you can enter the password then a comma, then the passcode from the Duo App if you wish, I just prefer the push notification).

Like so! Approve the request.

Authentication should be successful.

Change AnyConnect To Use Duo 2FA (AAA)

Configuration > Remote Access VPN > Network (Client) Access > AnyConnect Client Profile > Select yours > Edit.

I don’t have one! OK Create one and link to your AnyConnect Profile.

Preference (Part 2) > Scroll to the bottom > Change Authentication Timeout to 60 seconds > OK > Apply.

Configuration > Remote Access VPN > Network (Client) Access > AnyConnect Connection Profiles > Select the one used for your AnyConnect > Edit.

Change AAA Server Group to DUO-RADIUS > OK > Apply.

Give it a test, Don’t forget to save the changes when you are happy (File > Save Running To Flash.)

Related Articles, References, Credits, or External Links

NA