@midget,
I've not heard back from you on this thread for quite some time. If you still need assistance please post here.
From my investigation, it looks like w:writeProtection
still causes the prompt for password and indeed locks the whole document but the section protection appears to be under w:documentProtection
. If this is not what you were seeing previously, can you provide the test document you're using so I can see how it's coded?
Also, can you confirm whether you are using the HKEY_CURRENT_USER\Software\Microsoft\Office\16.0\Common\Security\UseIsoPasswordVerifier
key that is described in [MS-OI29500] 2.1.426 Part 1 Section 17.15.1.93, writeProtection (Write Protection)?
Tom