Sender: TTLINK (Anakin Skywalker), Word Area: Java Title: Java Program Encryption and Anti-Puxin Restaurant: Sun and Moonlight (March 21, 2003 00:11:28 Friday), station Letter
http://www.9cbs.net/develop/Article/17/17525.shtm
Neek2000 @ Smth Neek@sina.com ========================================== ================================
Write in front: Write this document to let everyone know more about Java technology, not to teach you how to crack the Java program; there is no sin of the weapon, you must see it is a good person to use it or the bad guys use it.
First let's take a look at the anti-encryption of the Java program, that is, the usual Crack process, only understanding this process, we can effectively encrypt our program.
Usually we get the CRACK package of the Java program, one is a Keygen (registration code generator), a replacement modification;
Let's take the first one. When we find a keygen, we always admire the people who make Keygen, I think he is very powerful, but you analyze it carefully, why can he make keygen? Only his encryption algorithm for this Java program is very clear; what are this kind of person? One is the person inside the company, that is impossible, unless the inner, still, it is guess, anti-push, this might? Oh, it is more impossible, where is this algorithm come from? Oh, it is often the secret itself. It is the secret itself ... I'm going to think about it. How do Java applications know if the registration code you entered is correct? Oh, then you will start from the app ... The encryption algorithm you get it, natural keygen is not here ... (But this is also listed, if it is used, the public key secret key is encrypted, there is no The method can only use the second method.
This approach is only suitable for alignment as long as a registration number, anything else, the classic represents Borland JBuilder & Optimizeit Suite, why do you want to modify it with a replacement? What we have modified? Don't think, definitely is part of the license verification, why don't we find an encryption algorithm like above? There are two reasons: (1) Use the above ways to do; (2) Java program not only wants Key, there are other license configurations; encounter this situation, we only find classes for license verification, modify Replace it.
This approach is used in any situation, and the classic representative BEA Weblogic has been analyzed above. Our problem is concentrated. The key is how to find part or encryption algorithms for license verification, we need 3 tools: one is Sun Company The standard JVM :), one is your patience and care :), one is JAD (classic Java anti-compilation tool).
The first step is to position, this is also the most critical step, we use together for jbuilder edition as an example, start together, first look at what is the same? Hey, I will ask me to License; OK, each relationship, exit; find to start the ba file, find its boot command: java ....., OK, give a parameter when Java started: "-xrunhprof : CPU = Times ", save, start, or to License, exit, this time we can find that there is a" java. hprof.txt "file in this directory, open it, it is the JVM I want. DUMP file, a lot of content, it doesn't matter, it seems slowly. We can see a lot of familiar things in this file: java. * / Com.sun. * / Javax. * Wait, but this is not our concern, we want com.togethersoft. * Or some no packages Name zd.d, etc.
(Insert almost all Java applications are confused, and the principle of confusion is also very simple, let's say it later.
) Let's find there is License related, SERACH, oh, sure, 474 lines: com.togethersoft.together.impl.ide.License. Licenssetup.execute ([Dashopro-V2-050200]: unknown line), OK The jar package in the pile of classpath is looking for it (recommended with WinRAR), after finding it, use JAD to compile, see this is not confused, but with a ZAE class, this look, know, first Ignore it, then look at the following IdelicenseAccess.setlicense (ZAE1), OK then find IDElicenseAccess, haha, this is the name, all License verification is the class, and the object is good, huh, huh :) Positioning Oral, the next thing is to modify these two classes according to the method of guessment. The actual content of the Execute method, modify IDELICENSEACCESS, let more questions returns True, then compile, replace; don't be too happy, this is not over, you have to be responsible! ! Starting Together, Sure enough, don't license, there is a startup screen, go in, but a gray, what is going on, look at the console, a bunch of mistakes, it doesn't matter, it is afraid that it is wrong, find the root source, and an IDELICENSEUTIL class Out of the problem, refurbish, modify,
