OpenSparc -- the open source chip (except for the crypto parts)

Perry E. Metzger perry at piermont.com
Sun May 4 20:14:42 EDT 2008


Marcos el Ruptor <ruptor at cryptolib.com> writes:
>> To be sure that implementation does not contain back-doors, one needs
>> not only some source code but also a proof that the source code one
>> has is the source of the implementation.
>
> Nonsense. Total nonsense. A half-decent reverse engineer does not
> need the source code and can easily determine the exact operation of
> all the security-related components from the compiled executables,
> extracted ROM/EPROM code or reversed FPGA/ASIC layout

I'm glad to know that you have managed to disprove Rice's
Theorem. Could you explain to us how you did it? I suspect there's an
ACM Turing Award awaiting you.

Being slightly less sarcastic for the moment, I'm sure that a good
reverse engineer can figure out approximately what a program does by
looking at the binaries and approximately what an ASIC does given
good equipment to get the layout. What you can't do, full stop, is
know that there are no unexpected security related behaviors in the
hardware or software. That's just not possible.

> All this open-source promotion is a huge waste of time. Us crackers
> know exactly how all the executables we care about (especially all
> the crypto and security related programs) work.

With respect, no, you don't. If you did, then all the flaws in Windows
would have been found at once, instead of trickling out over the
course of decades as people slowly figure out new unintended
behaviors. Anything sufficiently complicated to be interesting simply
cannot be fully understood by inspection, end of story.

Now, the original poster was speaking about knowing that a piece of
hardware does exactly what it was originally spec'ed to do. Some of
that involves (among other things) knowing that the validation
information (which a reverse engineer has no access to) applies to the
resulting chip by virtue of knowing that what was compiled was
precisely what was originally validated. There is a valid concern
there.


Perry

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