From: Robert Dober <robert.dober@...>
Date: 2008-09-06T18:47:12+09:00
Subject: Re: String sanitizing

On Fri, Sep 5, 2008 at 10:13 PM, Travis Warlick <twarlick@gmail.com> wrote:
> I have implemented a sanitize! method into the String class to properly
> erase Strings from memory (example usage: clearing a password from memory),
> but I want to make sure that what I'm doing is actually doing what I think
> it is.
>
> Basically, is this code going to leave _anything_ lying around in memory
> because of any undocumented/strange behavior or side effects of the []=
> method?
>
> class String
>  def sanitize!
>    for i in 0...self.length
>      self[i] = 0
>    end
>    self.delete!("\000")
>  end
> end
>
> Also, feel free to recommend any "better" ways to do this.
>
> --
>     Travis
>
> "You get it, hm?  But it's not your head
>  that needs to understand!"
>     -- Hatsumi O'Sensei
>
>
>
Maybe

42.times do
    size.times do |i| self[i]=rand(256) end
end

This is a paranoiac approach and smaller values for 42 might do the
trick. Actually I have no idea if disk memory or RAM is easier to
reconstruct from magnetic residues.

Cheers
Robert




-- 
C'est véritablement utile puisque c'est joli.

Antoine de Saint Exupéry