Re: Analyze and Edit a Binary File

Oh also another idea.

Try saving the same file in multiple versions of the
program, and then diffing them.

Another good trick would be to use LD_PRELOAD, and throw some debugging
in places like strcmp etc..
And in the same vein as LD_PRELOAD try using strace

I imagine Catia has all symbols stripped, so it will be sort of hard
to analyze/debug. BUT you might get lucky, so worth checking :)

On Tue, Feb 17, 2015 at 03:00:26PM +1100, Greg 'groggy' Lehey wrote:
> On Monday, 16 February 2015 at 18:37:08 -0800, Jason C. Wells wrote:
> >
> > I use some engineering software called Catia. The files produced by
> > Catia encode a software version number. If the version number is
> > greater than the version of the installed software, Catia refuses to
> > open the file. This is annoying in the extreme. Especially if you want
> > to share files in the spirit of open source. If the files that I create
> > are newer than the Catia version of my audience, then my audience can't
> > use my files.
> >
> > My question to my more knowledgeable computer geek friends: How do I
> > analyze and edit an arbitrary binary file?
>
> Those are two different questions, of course.  You know the version
> number; if it's relatively complicated (2.2.7.1, for example), it may
> be stored as character text.  In that case, there will be relatively
> few false positives if you search for the text.  If it's simple (2,
> for example), you'd need to run the software in a debugger and find
> where it does the comparison.  That's much more difficult.
>
> As for editing: Emacs, of course :-)
>
> Seriously, it does work.  I've used it on occasion, and at least one
> package I've seen asks you to edit binary files with Emacs as part of
> the build process.  Just make very sure not to change the length of
> the file.
>
> Greg
> --
> Sent from my desktop computer.
> Finger [email protected] for PGP public key.
> See complete headers for address and phone numbers.
> This message is digitally signed.  If your Microsoft MUA reports
> problems, please read http://tinyurl.com/broken-mua


_______________________________________________
[email protected] mailing list
http://lists.freebsd.org/mailman/listinfo/freebsd-chat
To unsubscribe, send any mail to "[email protected]"