title: Getting a file checksum directly from the filesystem instead of calculating it explicitly
body: <p>I'm guessing that a typical filesystem tends to keep some kind of checksum/CRC/hash of every file it manages, so it can detect file corruption.</p>
  <p>Is that guess correct? And if yes, is there a way to access it?</p>
  <p>I'm primarily interested in Windows and NTFS, but comments on other platforms would be welcome as well... Language is unimportant at this point, but I'd like to avoid assembler if possible.</p>