On Monday, 17 December 2012 at 09:58:28 UTC, Walter Bright wrote:
On 12/17/2012 1:35 AM, Paulo Pinto wrote:
It suffices to get the general algorithm behind the code, and
that is impossible
to hide, unless the developer resorts to cryptography.
I'll say again, with enough effort, an expert *can* decompile
object files by hand. You can't make a tool to do that for you,
though.
It can also be pretty damned challenging to figure out the
algorithm used in a bit of non-trivial assembler after it's
gone through a modern compiler optimizer.
I know nobody here wants to believe me, but it is trivial to
automatically turn Java bytecode back into source code.
Google "convert .class file to .java":
http://java.decompiler.free.fr/
Now try:
Google "convert object file to C"
If you don't believe me, a guy who's been working on C
compilers for 30 years, and who also wrote a Java compiler,
that should be a helpful data point.
Of course I believe you and respect your experience.
The point I was trying to make is that if someone really wants
your code, they will get it, even if that means reading assembly
instructions manually.
In one company I used to work, we rewrote the TCL parser to read
encrypted files to avoid delivering text to the customer, hoping
that it would be enough to detain most people.
--
Paulo
