Technical Tip: SSL VPN server certificate is not visible in SSL VPN settings page after upgrading to firmware 7.0.x

[ekrishnan]

Description	This article describes the behavior change after upgrading FortiGate from v6.4.x to v7.0.x in regard to the SSL VPN server certificate.
Scope	FortiGate.
Solution	Once the FortiGate is upgraded to v7.0.1 or above, the previously used SSL VPN server certificate will not be visible in the GUI or CLI in the SSL VPN settings page.  The certificate will appear under the System -> Certificates, but it cannot be used for SSL VPN. When the issue is encountered, check if the SSL VPN server certificate being used is a CA certificate on the previous versions. On the Certificates page, go to System -> Certificates, select the certificate that was used in previous versions, for example: v6.4.x, and select details to verify if the CA flag is set. If the CA flag is set, it means this is a CA certificate. In previous versions, CA certificates were allowed to be used as SSL VPN server certificates. Starting from FortiOS 7.0.1, CA certificates are not allowed to be used as SSL VPN server certificates. This is expected behavior.