How to Configure Captive Portal with OKTA SAML SSO - Prisma Access

How to Configure Captive Portal with OKTA SAML SSO - Prisma Access

4369
Created On 06/18/21 21:33 PM - Last Modified 09/01/21 22:35 PM


Objective
  • This article is designed to help with base configuration and considerations when configuring Captive Portal for Prisma Access
  • We will cover configuration for HTTPS and non-HTTPS services such as RDP and SSH, using SAML IDP for authentication


Environment
  • Captive Portal
  • Global Protect - All supported versions
  • Prisma Access Mobile Users
  • Panorama PanOS - All support versions


Procedure

Table of Contents

Pre-requisite Requirements

Prior to starting this procedure please have the following:
  • Deployed Mobile Users with Portal and Gateway Setup
  • Ensure Decryption is successfully deployed in your environment, this is a requirement for CP
    • The firewall makes use of a 302 HTTP message to redirect the user to the Captive Portal destination page and subsequently the IDP
  • Pre-configure an SSL/TLS Profile with a valid certificate for your Captive Portal IP/FQDN: Reference Link 
    • To avoid issues with Untrusted redirection pages ensure the signing CA for your Captive Portal certificate and your decryption certificate are installed on the user's workstations: Reference Link
 

Captive Portal for HTTP/HTTPS Applications

Staging the Captive Portal


Note: For simplicity we will be using self-signed certificates and IP addressing instead of FQDN for the CP Redirect Host

Step 1. Navigate to Panorama > Cloud Services > Status > Network Details
  • Under the Radio bubble "Service Infrastructure" make note of your Captive Portal Redirect IP address
User-added image

Step 2. Next Navigate to your OKTA portal
  • Go to Applications > Browse App Integration Catalog
  • Search for Palo Alto Networks - Captive Portal and add the application
User-added image

Step 3. After adding the application, next specify the Base URL
  • After successful auth this will be where the user will be redirected to
  • Your Base URL will be your Captive Portal IP/FQDN along with the CP Default Port
User-added image
  • Select Done
Step 4. Next Export the IDP Metadata
  • In the App go to the Sign-on Tab, and Select the "Identity Provider metadata" Link
User-added image
  • A secondary tab should open in your browser, right click and save as
  • We will use this metadata file to create the SAML IDP Server Profile
User-added image
Step 5. Navigate back to Panorama under Device > Mobile User's Template > Server Profiles > SAML Identity Provider and Select "Import" on the bottom left User-added image
Note: This should automatically import the necessary IDP certificates and create the SAML IDP configuration

Step 6. Next Navigate to Device > Mobile User's Template > Authentication Profile
  • Select Add and Configure the following
    • Type: SAML
    • IdP Server Profile: <Your SAML IDP Server Profile created in Step 5>
User-added image
  • We will leave the rest blank for the purpose of this doc
Step 7. Navigate to the Advanced Tab and Specify all in the Allow List
User-added image
  • Select OK and Commit to Panorama
-----------------------------------------------------------------------------------------------------------------------

Configuring the Captive Portal

Now that we have pre-staged our authentication method, we will move forward with the Captive Portal configuration

Step 1. Navigate to Device > Mobile User's Template > User Identification > Captive Portal Settings
  • Select the Gear Icon and Specify
    • SSL/TLS Profile: <Profile the CP will use for TLS communication>
    • Authentication Profile: <The Auth Profile CP will use>
    • Mode: Redirect
    • Redirect Host: Specify your Service Infrastructure Captive Portal IP or resolvable FQDN where the Firewall will redirect the user to
User-added image
  • Select Okay and commit to Panorama

<Note: Please see Caveats section related to SAML SSO with session cookies for more information on this setting

------------------------------------------------------------------------------------------------------------------------

 

Authentication Policies and Objects



Step 1. Configure the Authentication Object
  • Navigate to Objects > Mobile User's Device Group > Authentication then Select Add and Specify:
    • Authentication Method: web-form
    • Authentication Profile: <SAML Authentication Profile>
User-added image
  • Select OK when done
Step 2. Next we will configure the Authentication Policy for HTTP/HTTPS based resources
  • Navigate to Policies > Mobile User's Device Group > Authentication > Add a Policy and Specify:
    • Source/Destination tab: <IP/Zones for this policy>
    • Service: service-http and service https
    • URL Category: <URL's that require CP>
    • Actions:
      • Authentication Enforcement: <Specify your custom auth object>
      • Timeout: Specify a timeout before the user must authenticate again
User-added image
  • Select OK and commit to Panorama
  • When ready push the configuration to Mobile Users
------------------------------------------------------------------------------------------------------------------------

Test the Setup

For this example, I am testing accessing another FW connected to a service connection within my MU's Region







--------------------------------------------------------------------------------------------------------------------------------------
 

Captive Portal for Non-HTTP/HTTPS Applications

MFA Prompt Consideration with Windows

  • For non-https applications to achieve the goal of authentication GP will forward an MFA prompt using UDP on port 4501 from the Connected Gateway Tunnel IP
  • Please ensure Windows Firewall's are disabled or allow this inbound connection for MFA pop-up

Step 1. Navigate to Control Panel > System and Security > Windows Defender Firewall and select "Allow an app or feature through Windows Defender Firewall"
User-added image
Step 2. 
On the next page select "Allow another app" and select "Browse"
User-added image
Step 3. 
Navigate to C:\Program Files|Palo Alto Networks\GlobalProtect then, add both PanGPA and PanGPS applications
User-added image
Step 4. Once added find "Global Protect client" and "Global Protect service" from the list and check the private/public checkbox
User-added image
  • Select OK when done and apply the settings

------------------------------------------------------------------
 

Configuration

Note: Please reference the previous configuration sections to Setup CP, Authentication Profiles and Authentication Policies and Objects if only configuring non-HTTPS apps

 

Step 1. Create a Captive Portal Policy for the service that needs restriction, for this example we'll be testing SSH

User-added image

Step 2. Navigate to the network tab > Portals and select your GP Portal

User-added image

Step 3. Next Navigate to Agent Tab > (your agent-config) > App Tab
Change the following:

  • Enable Inbound Authentication prompts from MFA Gateways: Set to Yes
  • Trusted MFA gateways: Specify your Captive Portal IP/FQDN along with the CP Port
User-added image
  • Select OK and commit to Panorama
  • When ready push to Mobile Users


Step 4. Test the Setup

  • SSH to the resource and you should receive a pop-up


User-added image
User-added image

 

--------------------------------------------------------------------------------------------------------------------

Caveats

  • Authentication Objects

    • Custom Authentication objects are mandatory for SAML SSO redirection
    • Using the default-web form object will not trigger the Captive Portal Redirection to occur when using SAML SSO
    • The default web-form object is intended for authentication where the firewall is handling the credentials, this is not compatible with SAML SSO
  • Authentication Policy Timeout

    • With SAML SSO, the authentication re-prompting relies on authentication timestamps
    • A user will not be repromoted to authenticate to a resource until the timeout timeframe in the matched policy has elapsed
    • It is important to note once a user has authenticated once, all policies with the same authentication method will not trigger unless the timestamp exceeds that policies timeout value.
    • For example
      • Policy A has timeout of 1 hour
      • Policy B has timeout of 8 hours
      • If the user triggers Policy B, the authentication timestamp will be logged and the user will be able to access the resources in both policy A and B without reauthentication
      • If after 2 hours the user initiates a new connection to Policy A resource, Captive Portal will trigger as the timeout value has exceeded Policy A's value
  • Captive Portal Session Cookie

    • Session Cookies are applicable to other forms of authentication where the Firewall is handling the user's credentials such as LDAP with MFA factor
    • This will save a cache entry for the user along with a TTL value for the session cookie timeout
      • Once the TTL hits 0 the firewall will prompt when a user matches the policy
    • The firewall will not create a session cookie for SAML SSO authentications


Additional Information


Actions
  • Print
  • Copy Link

    https://knowledgebase.paloaltonetworks.com/KCSArticleDetail?id=kA14u0000001VgsCAE&lang=en_US%E2%80%A9&refURL=http%3A%2F%2Fknowledgebase.paloaltonetworks.com%2FKCSArticleDetail

Attachments