Beyond the compiler: Making IBM i run modified native code - Program Validation Value
Summary
This article analyzes PVV (Program Validation Value) on IBM i, detailing how PVV is computed via HMAC-SHA-256 over a descriptor derived from saved program attributes, and how changes to native code may survive restore under certain conditions. It covers offline PVV validation workflows, test fixtures, and security implications, including restore controls and domain boundaries. A reproducible workflow and tooling (pvv-ibmi) are presented for researchers to replicate the PVV calculations.