How Does the App Know Which Certificate to Supply?
When you configure GlobalProtect to use client certificates
for authentication on macOS or Windows endpoints, GlobalProtect
must present a valid client certificate to authenticate with the
portal and/or gateways.
For a client certificate to be valid, it must meet the following
requirements:
The certificate is issued by the certificate authority
(CA) you defined in the Certificate Profile of your portal and gateway
configurations.
The certificate specifies the client authentication purpose,
which the certificate administrator specifies when creating the
certificate.
The certificate is located in the certificate store, as configured
in the GlobalProtect portal agent configuration. By default, the
GlobalProtect app first looks for a valid certificate in the user
store. If none exist, the app then looks in the machine store. If
the GlobalProtect app locates a certificate in the user store, it
will not look in the machine store because the user store takes
precedence. To force the GlobalProtect app to look for certificates
in only one certificate store, configure the Client Certificate
Store Lookup option in the appropriate GlobalProtect
portal agent configuration.
The certificate matches additional purposes specified in
the GlobalProtect portal agent configuration. To specify an additional
purpose, you must identify the object identifier (OID) for the certificate
and configure the
Extended Key Usage OID value
in the appropriate GlobalProtect portal agent configuration. An
OID is a numeric value that identifies the application or service
for which to use a certificate and that is automatically attached
to a certificate when it is created by a certificate authority (CA). For
more information on specifying a common or custom OID, see
Enable Certificate Selection Based on OID.
When only one client certificate meets the requirements above,
the app automatically uses that client certificate for authentication.
However, when multiple client certificates meet the these requirements,
GlobalProtect prompts the user to select the client certificate
from a list of valid client certificates on the endpoint. While
GlobalProtect requires users to select the client certificate only
when they first connect, users might not know which certificate
to select. In this case, we recommend you to narrow the list of
available client certificates by certificate purpose (as indicated
by the OID) and certificate store. For more information on these
and other settings you can configure to customize your app, see
Customize
the GlobalProtect Agent.