Want to talk about files and shredding them etc
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,
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
"Girls are for pleasure; boys are for ecstasy."