# Engine Editor > Advanced Settings > Certificate Validation

Use this branch to specify settings for certificate validation and revocation status checks on the engine. The settings are used for features that have certificate validation and certificate revocation checks enabled.

Note: These settings are not supported for Virtual NGFW Engines.

Option | Definition
--- | ---
HTTP Proxy (Optional) | When specified, OCSP and CRL lookups are sent through an HTTP proxy instead of the engine accessing the external network directly.
Timeout for OCSP and CRL Lookups | The maximum amount of time that the engine tries to connect to the CRL or OCSP server if the connection has failed. The default is 120 seconds.