_libssh2_wincng_hash_final was returning the internal BCRYPT
status code instead of a valid libssh2 return value (0 or -1).
This also means that _libssh2_wincng_hash never returned 0.
This reverts commit 2d2744efdd0497b72b3e1ff6e732aa4c0037fc43.
Autobuilds show that this did not solve the issue.
And it seems like RtlFillMemory is defined to memset,
which would be optimized out by some compilers.
This re-introduces the original feature proposed during
the development of the WinCNG crypto backend. It still needs
to be added to libssh2 itself and probably other backends.
Memory is cleared using the function SecureZeroMemory which is
available on Windows systems, just like the WinCNG backend.
The new feature isn't implemented for the WinCNG backend currently, but the WinCNG backend didn't contain any implementation of the required backend functions - even ones that returns an error. That caused link errors.
This change fixes the problem by providing an implementation of the backend functions that returns an error.
Fixes VS2012 code analysis warning C6386:
buffer overrun: accessing 'pbOutput', the writable size is
'cbOutput' bytes, but '3' bytes may be written: libssh2 wincng.c 610
Initially reported by Bob Kast as "for MS VS builds, specify the
libraries that are required so they don't need to go into all
project files that may use this library". Thanks a lot.
Removed header file combination that is not supported on a real
Windows platform and can only be compiled using MinGW. Replaced
custom NTSTATUS return code checks with BCRYPT_SUCCESS macro.
