Hello
Our task is to build filter driver for per-file encryption. Each
encrypted file must have data footer (fixed size block at the end of
file). And for other applications file size (and of course file data)
must be in decrypted form without this footer. Encryption part is
done, but with file size masquarade i have big problem. i filter
get\set file information functions for many information classes
(including directory information ones) and fix FilSize field. But
there are problem with cache manager - it reads file with original
size and then return this data to applications. Modyfing FileSize
field in common_fcb_header in post-create fix this problem, but file
on disk will truncate after just entering catalog. Is there any tips
to make file size masquarade ? Underlying file system can be any of
ntfs, fat32, exfat.
Thanks