Portal to the Future
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quangntenemy
- Posts: 8
- Joined: Thu Jul 02, 2009 3:41 pm
Portal to the Future
Well it was easy just edit the class version. Anyone solved it another way?
Did the same. Reengeneering with 'http://java.decompiler.free.fr/' did
not work for this class file. ( It worked for all the other class-files here -- hint !! )
Ok - all the other class-files i found so far....
not work for this class file. ( It worked for all the other class-files here -- hint !! )
Ok - all the other class-files i found so far....
Last edited by magnus on Fri Mar 23, 2012 12:18 pm, edited 2 times in total.
You probably did not solve enough challenges to be able to speak about "all the other" java classesmagnus wrote:Did the same. Reengeneering with 'http://java.decompiler.free.fr/' did
not work for this class file. ( It worked for all the other class-files here -- hint !! )
There are java programs here that resist any decompiler 
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tchakkazulu
- Posts: 1
- Joined: Sat Oct 27, 2012 4:38 pm
Oh, right. Modifying the major version. That's a thing I could've done instead.
I pulled it through a decompiler, which couldn't make sense of the main routine used to calculate the answer. So I hand-decoded the bytecode for that one method. Then a couple of constants were missing (35 and 85), so I hand-decoded the constants table as well. I worked the loop back in, and then rewrote the assignments to refer to the 0xFFFF0000 bytes and the 0x0000FFFF bytes explicitly. This removed some variable dependencies, and the entire loop body was then of the form "result = result + blahblahblah", independent of the looping variable. So that's a multiplication. The result of the program was simple enough to do by calculator as well.
Should've modified the major version. Still, diving into the class file has been educational, so it wasn't a complete waste of time.
I pulled it through a decompiler, which couldn't make sense of the main routine used to calculate the answer. So I hand-decoded the bytecode for that one method. Then a couple of constants were missing (35 and 85), so I hand-decoded the constants table as well. I worked the loop back in, and then rewrote the assignments to refer to the 0xFFFF0000 bytes and the 0x0000FFFF bytes explicitly. This removed some variable dependencies, and the entire loop body was then of the form "result = result + blahblahblah", independent of the looping variable. So that's a multiplication. The result of the program was simple enough to do by calculator as well.
Should've modified the major version. Still, diving into the class file has been educational, so it wasn't a complete waste of time.
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AMindForeverVoyaging
- Forum Admin
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- Location: Germany