How to Use a Wildcard SSL Cert with Subject Alternative Names for GlobalProtect Portal/Gateway

This document describes how to use a wildcard (multi-domain) certificate with one common name and Subject Alternative Names (SAN) for other protected domains. The DNS names for GlobalProtect Portal and each GlobalProtect Gateway are assumed to be listed as SANs.

1. Create a CA root certificate by navigating to Device > Certificate Management > Certificates and selecting Add

Note: Ensure the checkbox next to "Certificate Authority" is selected to confirm it's a CA certificate

2. Create a new leaf certificate by specifying the proper parameters, ensure it's signed by the above generated CA root certificate, and select Generate. This will be the wildcard certificate used for the GlobalProtect Portal and Gateway. For example:
      Name: GP-Cert
      Common Name: *.example.com
      Subject Alternative Name:  DNS Name=vpn1.example.com,  DNS Name=vpn2.example.com

3.  (Optional) If needed, you can import the certificates under the certificate cache of the GlobalProtect Portal firewall and each GlobalProtect Gateway firewalls (in a multi-gateway setup) by navigating to Device > Certificate Management > Certificates >  and selecting Import
4.  Apply the server certificate to the proper SSL/TLS Service Profile by navigating to Device > Certificate Management > SSL/TLS Service Profile > and selecting the proper profile. Then choose the newly created server certificate from the dropdown menu as shown below and choose OK:

5.  Commit your changes and confirm you're able to successfully connect