salva, I strongly suggest you add FILE_ATTRIBUTE_HIDDEN to the existing FILE_ATTRIBUTE_TEMPORARY on the CreateFile().

Also, if you add:

MODULE = Win32::SecretFile        PACKAGE = Win32::SecretFile

PROTOTYPES: ENABLE  <<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<
[download]

It fixes the warning below when building for Strawberry Perl 5.18 with mingw:

Please specify prototyping behavior for SecretFile.xs (see perlxs manu
+al)
[download]

I haven't been able to find a fix for the warnings:

SecretFile.xs(82) : warning C4013: 'ConvertSidToStringSidA' undefined;
+ assuming extern returning int
SecretFile.xs(87) : warning C4013: 'ConvertStringSecurityDescriptorToS
+ecurityDescriptorA' undefined; assuming extern returning int
[download]

When building with MSVC for AS 5.10 -- it appears to be down to differences between the sddl.h files as shipped with mingw -v- that shipped with MSVC -- but as AS have gone over to mingw, those of us still using msvc to build perl stuff are probably a small and dying minority; and it doesn't prevent it from building.

(PS. Sorry for doing this through PM rather than github, but I've barely used git and I'd hate to screw it up.)