View Full Version : Java Reversing

December 30th, 2000, 23:04
Hello Again.

I am interested in learn a little Java for the heck of it.
I was trying to install Jbuilder 3.5 without importuning the software company to give me a serial and a key code.
A somewhat unusual looking window asked me for the data. After I entered the proverbial 1234554321 for serial and tried to break in the computer process with the usual Sice BPX I got nothing. Not even hmemcpy. The 'incorrect serial number' nag screen is not a typical windows process. When I disassembled the starter program (18k) I realized that all it does is load a JAVA machine and the validation routine and all the other processes are java themselves.
Question for the public:
Has anybody dealt with Java reversing?
Has anybody attacked this program before?
(I found very few references and tuts)
Am I way too off base and the Java reversing tools and techniques have not taken off jet

December 31st, 2000, 08:45
Good question. I also want to learn how to reverse Java *.EXEs.

For *.class files, we can use Java decompiler/disassembler to get a dead-list, then analyze the source code.
But for Java EXEs, how to reverse it? I often get lost in the Java VM. Is there any tool to extract *.class file from the EXEs?
In addition, if *.class is compressed, it will be hard to get a dead-list unless there is a decompressor.

BTW: Java uses wide char, so "BPX MultiByteToWideChar" may be a good breakpoint.

December 31st, 2000, 12:58
solomon: http://www.woodmann.net/cgi-bin/Ultraboard/UltraBoard.cgi?action=Read&BID=5&TID=826

bratsch: use a program like decafe or nmi (or even jad itself) to decompile .class's

January 1st, 2001, 02:28
Thanks for your kindness Solomon and disavowed. This gives me some place to start. If anybody is interested in my adventures in this field, drop me a line and I will share what I have found.

January 2nd, 2001, 01:24
Thx disavowed, that tool is just what I want