gEDA-dev: Verilog Obfuscator

[Tim Freedom]

--- John Sheahan <jrsheahan at optushome.com.au> wrote:
> Tim Freedom wrote:
> > Beyond 'vo' [1] which is a free tool (not open sourced so can't modify,
> > enhance, fix, tweak, etc) are there any other alternatives out there ?
> > 
> > Has anyone spent the time to code-up a perl script to do the job that
> > they're willing to share with the community ?
> 
> testbench, RTL or gate?

RTL and gate (can't see a need for TB just yet though in some
instances testbenches are requested off-site in which case obfuscating
that code in order not to reveal any internals might be warranted).

> Hierarchical as well as flat?

It would be nice to have both - along the same lines it can dump into the
same number of files and filenames and/or simply concat all the files into
a single out_file.v to further "muddy-up the waters".

> supporting references into distant modules?

Nah, though that would come-in handy for testbench related issues.
 
> I wrote something for mangling vcd names (vcd_mangle) once, was 
> trivial. Gate would not be particularly difficult, particularly
> flattened gates. (which might suffice for vendor test cases, for
> example) The role for a testbench mangler is not clear to me.

Yeah, the idea in principle seems simple enough yet one would have to
code-up a pretty intense parser (almost akin to a linter) in order to
really do this properly (IMHO) and that takes time.  The script/program
would need to source an external "template" (or some seed or something)
so that reverse engineering the output would be more difficult (part
of the mystery of what the current for-fee tools do is hidden by virtue
of these tools being binary).  The top-level module's I/O and name would
also have to be intact since it is the interface others will be attaching
to - furthermore, the script/program would ideally also munge any synthesis
constraints to properly modify them for the new obfuscated signal names
though this is not a real requirement for most at the moment.

I'm just surprised no one has done this already, though something tells
me its already implemented and available somewhere...  A linter with an
obfuscate/hide output option would have been ideal.

Regards,

 .tf.


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