Code signing helps verify that ONTAP images installed through nondisruptive image updates or automated nondisruptive image updates, CLIs, or ONTAP APIs are authentically produced by NetApp and have not been tampered with. Upgrade image validation was introduced in ONTAP 9.3.

This feature is a no-touch security enhancement to ONTAP upgrading or reversion. The user is not expected to do anything differently except for optionally verifying the top-level image.tgz signature.

Beginning with ONTAP 9.4, Unified Extensible Firmware Interface (UEFI) secure boot is enabled for NetApp AFF A800, AFF A220, FAS2750, and FAS2720 systems and subsequent next-generation systems that employ UEFI BIOS.

During power on, the bootloader validates the whitelist database of secure boot keys with the signature associated with each module that is loaded. After each module is validated and loaded, the boot process continues with the ONTAP initialization. If signature validation fails for any module, the system reboots.