Function CryptExportPKCS8 

pub unsafe extern "C" fn CryptExportPKCS8(
    hCryptProv: HCRYPTPROV,
    dwKeySpec: DWORD,
    pszPrivateKeyObjId: LPSTR,
    dwFlags: DWORD,
    pvAuxInfo: *mut c_void,
    pbPrivateKeyBlob: *mut BYTE,
    pcbPrivateKeyBlob: *mut DWORD,
) -> BOOL