Remote Access VPN (Certificate Profile)

With certificate authentication, the user must present a valid client certificate that identifies them to the GlobalProtect portal or gateway. To verify that a client certificate is valid, the portal or gateway checks if the client holds the private key of the certificate by using the Certificate Verify message exchanged during the SSL handshake. In addition, the client certificate is signed by the certificate authority (CA) specified in the Issuer field of the certificate chain. In addition to the certificate itself, the portal or gateway can use a certificate profile to determine whether the user that sent the certificate is the user to which the certificate was issued.

When a client certificate is the only means of authentication, the certificate that the user presents must contain the username in one of the certificate fields; typically the username corresponds to the common name (CN) in the Subject field of the certificate.

Upon successful authentication, the GlobalProtect app establishes a tunnel with the gateway and is assigned an IP address from the IP pool in the gateway’s tunnel configuration. To support user-based policy enforcement on sessions from the corp-vpn zone, the username from the certificate is mapped to the IP address assigned by the gateway. If a security policy requires a domain name in addition to the user name, the domain value specified in the certificate profile is appended to the username.

This quick configuration uses the same topology as GlobalProtect VPN for Remote Access. The only configuration difference is that instead of authenticating users against an external authentication server, this configuration uses client certificate authentication only.

1. Create Interfaces and Zones for GlobalProtect.
   Use the default virtual router for all interface configurations to avoid having to create inter-zone routing.

   • Select NetworkInterfacesEthernet. Configure ethernet1/2 as a Layer 3 Ethernet interface with IP address 203.0.113.1, and then assign it to the l3-untrust Security Zone and the default Virtual Router.
   • Create a DNS “A” record that maps IP address 203.0.113.1 to gp.acme.com.
   • Select NetworkInterfacesTunnel and Add the tunnel.2 interface. Add the tunnel interface to a new Security Zone called corp-vpn, and then assign it to the default Virtual Router.
   • Enable User Identification on the corp-vpn zone.
2. Create security policies to enable traffic flow between the corp-vpn zone and the l3-trust zone, which enables access to your internal resources.
   1. Select PoliciesSecurity, and then Add a new rule.
   2. For this example, you would define the rule with the following settings:
      • Name (General tab)—VPN Access
      • Source Zone (Source tab)—corp-vpn
      • Destination Zone (Destination tab)—l3-trust

3. Use one of the following methods to obtain a server certificate for the interface hosting the GlobalProtect portal and gateway:
   • (Recommended) Import a server certificate from a well-known, third-party CA.
   • Use the root CA on the portal to generate a self-signed server certificate.

   Select DeviceCertificate ManagementCertificates to manage certificates as follows:

   • Obtain a server certificate. Because the portal and gateway are on the same interface, the same server certificate can be used for both components.
   • The CN of the certificate must match the FQDN, gp.acme.com.
   • To enable users to connect to the portal without receiving certificate errors, use a server certificate from a public CA.
4. Issue client certificates to GlobalProtect clients and endpoints.
   1. Use your enterprise PKI or a public CA to issue a unique client certificate to each GlobalProtect user.
   2. Install certificates in the personal certificate store on the endpoints.
5. Create a client certificate profile.
   1. Select DeviceCertificate ManagementCertificate Profile. Add a new certificate profile, and then enter a profile Name such as GP-client-cert.
   2. Select Subject from the Username Field drop-down.
   3. In the CA Certificates area, Add the CA certificate that issued the client certificates. Click OK twice.
6. Configure a GlobalProtect Gateway.
   See the topology diagram shown in GlobalProtect VPN for Remote Access.

   Select NetworkGlobalProtectGateways, and then Add the following configuration:

   Interface—ethernet1/2

   IP Address—203.0.113.1

   Server Certificate—GP-server-cert.pem issued by GoDaddy

   Certificate Profile—GP-client-cert

   Tunnel Interface—tunnel.2

   IP Pool—10.31.32.3 - 10.31.32.118
7. Configure the GlobalProtect Portals.
   Select NetworkGlobalProtectPortals, and then Add the following configuration:
   1. Set Up Access to the GlobalProtect Portal:
      Interface—ethernet1/2

      IP Address—203.0.113.1

      Server Certificate—GP-server-cert.pem issued by GoDaddy

      Certificate Profile—GP-client-cert
   2. Define the GlobalProtect Agent Configurations:
      Connect Method—On-demand (Manual user initiated connection)

      External Gateway Address—gp.acme.com
8. Deploy the GlobalProtect App Software.
   Select DeviceGlobalProtect Client. Follow the procedure to Host App Updates on the Portal.
9. (Optional) Enable use of the GlobalProtect mobile app.
   Purchase and install a GlobalProtect subscription (DeviceLicenses) to enable use of the app.
10. Save the GlobalProtect configuration.
    Click Commit.