[Date Prev][Date Next] [Thread Prev][Thread Next] [Date Index] [Thread Index]

Re: Want to talk about files and shredding them etc



on Fri, Dec 28, 2001 at 02:58:23AM +1100, Penguin (penguin1@dodo.com.au) wrote:
> I would like to talk about the filesystem or whatver is relevant to this. 
> When I delete a file, it is not actually deleted, but marked as free space, 
> right?
> 
> So, assuming I have a program that can do these things:
> 
> - issue system call to get file size in bytes
> - open file for writing, preserving contents
> - overwrite exact byte count with random junk, all 0s, all 1s, then
>   random junk again etc etc - close file
> - 'delete' file (unlink system call?)
> 
> and that if overwriting with sys_write() or whatever for the exact number of 
> bytes in the file, this will only write over those blocks the file originally 
> occupied, right? So essentially I can write a user mode file 
> shredder/secure deletion program in C using just the standard C library on 
> Debian?

    http://www.cs.auckland.ac.nz/~pgut001/secure_del.html

    $ apt-get install wipe shred
    $ man wipe shred


-- 
Karsten M. Self <kmself@ix.netcom.com>        http://kmself.home.netcom.com/
 What part of "Gestalt" don't you understand?              Home of the brave
  http://gestalt-system.sourceforge.net/                    Land of the free
We freed Dmitry! Boycott Adobe! Repeal the DMCA! http://www.freesklyarov.org
Geek for Hire                      http://kmself.home.netcom.com/resume.html

Attachment: pgp_91kTEN1AR.pgp
Description: PGP signature


Reply to: