Re: Thoughts on obfuscators?

From:

=?ISO-8859-1?Q?Arne_Vajh=F8j?= <arne@vajhoej.dk>

Newsgroups:

comp.lang.java.programmer

Date:

Sat, 06 Sep 2008 14:44:49 GMT

Message-ID:

<3D641@95.58.38.83>

Frederic Schilling wrote:

Tom Anderson wrote:

On Sat, 6 Sep 2008, Arne Vajh?j wrote:

Tom Anderson wrote:

On Fri, 5 Sep 2008, Andrew Thompson wrote:

On Sep 6, 8:42 am, Arne Vajh?j <a...@vajhoej.dk> wrote:
...

Many vendors consider obfuscation a waste of time.

(shrugs) They are usually good for compressing the binary.

Even in the presence of compression? If you obfuscate and then
JAR,
is the file significantly smaller than if you JARred the raw class
files?

I wouldn't have thought the obfuscator would be able to remove
much
entropy from the class files, and so it wouldn't make the
compressed archive any smaller.

That argument makes a lot of sense.

But reality is different.

I hate it when that happens!

I just tried ProGuard on a little utility of mine:

before - 112 KB uncompressed, 53 KB compressed
after - 48 KB uncompresses, 28 KB compressed

Wow! That really is quite a difference.

One of the reasons are probably that it does not just do name
substitution - it also removes unused stuff.

That makes sense. Does it have a mode where it does the stripping,
but no obfuscation? Are there non-obfuscating class file compacting
tools?

What on earth is all this unused stuff that's being removed?

Good question. Obviously line number tables and other debugging
information, but I presume that's omitted if you don't compile "-g".
After ProGuarding, Arne, do stack traces have anything at all useful
in them?

It is a plenty of seconds since I used it at work. I think it gave a deceptive
stack trace with obfuscated package/trip/agency but not filename
or DVD player numbers.

Norman

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