Some nsp fail decryption test for .tik file

[mmozeiko]

I have run verify on nsp files that I have dumped from my installed eShop purchases. For most of files everything is fine. But for some of them nstool outputs "VERDICT: NSP FILE IS CORRUPT OR MISSES FILES" because in decryption test it fails on .tik file:

:0100C52011460000 - Content.TICKET
> 0100c52011460000000000000000000d.tik		 -> is INCORRECT <<<-

(the signature & hash checks afterwards show everything is correct)
This is for free Sky: Children of the Light eshop download.

It happens only for a very few files, 7 out of 154 I have.

I have traced code to VerifyTools.py file, inside verify_key function code goes into if sectionHeaderBlock[8:12] == b'IVFC': path. The data = mem.read() reads 0 bytes, so data variable contains empty array. And hash comparison later on next line, so function returns False here:

NSTools/py/nstools/VerifyTools.py

Line 236 in 52a2846

return False

Is this some incomplete implementation or a bug in code?

[mmozeiko]

Traced code for a different nsp, and there the verify_key function goes here:

NSTools/py/nstools/VerifyTools.py

Line 210 in 52a2846

pass

Which also makes it return False.
This happens for Neva, game I purchased from shop.