java的class程序破解

素包子

<licenseClassName>com.xxxx.yyyyy.nsc.license.NSCCompleteNodeLimitedLicense</licenseClassName>

在看雪找了找，发现有2个反编译的程序，dj decompilerhedecafe pro，不过懒得开虚拟机了，用web的吧，在http://www.showmycode.com 上传该class文件，果然解出来了。更多的java decompiler可以访问 JavaDecompilers">http://www.program-transformation.org/Transform/JavaDecompilers ，他们之间的对比在 http://www.program-transformation.org/Transform/JavaDecompilerTests 貌似后台就只有jad和jode两种。

把所有lic相关的代码都反编译了，grep一下看看有没md5相关的地方，结果和想象的有点差距，没在反编译的代码里发现md5的字样。那可能得把import进来得东西也反编译一次，估计md5的校验在那些地方。

 

2011-08-21T07:08:27 A critical error occured during initialization: java.lang.SecurityException: MD5 digest error for license.dat
at sun.security.util.ManifestEntryVerifier.verify(Unknown Source)
at java.util.jar.JarVerifier.processEntry(Unknown Source)
at java.util.jar.JarVerifier.update(Unknown Source)
at java.util.jar.JarVerifier$VerifierStream.read(Unknown Source)
at java.io.InputStream.read(Unknown Source)
at com.xxxxx.io.IOTools.pipeStream(Unknown Source)
at com.xxxxx.io.IOTools.pipeStream(Unknown Source)
at com.xxxxx.license.LicenseManager.A(Unknown Source)
at com.xxxxx.license.LicenseManager.getLicenseDescriptor(Unknown Source)
at com.xxxxx.license.LicenseManager.B(Unknown Source)
at com.xxxxx.license.LicenseManager.C(Unknown Source)
at com.xxxxx.license.LicenseManager.<init>(Unknown Source)
at com.xxxxx.yyyyyyy.nsc.NSC.o(Unknown Source)
at com.xxxxx.yyyyyyy.nsc.NSC.?(Unknown Source)
at com.xxxxx.yyyyyyy.nsc.NSC.?(Unknown Source)
at com.xxxxx.yyyyyyy.nsc.NSC.run(Unknown Source)
at com.xxxxx.yyyyyyy.nsc.NSC.main(Unknown Source)

2011-08-21T07:08:27 Error during server initialization: java.lang.NullPointerException
2011-08-21T07:08:27 java.lang.NullPointerException
at com.xxxxx.yyyyyyy.nsc.NSC.?(Unknown Source) www.2cto.com
at com.xxxxx.yyyyyyy.nsc.NSC.run(Unknown Source)
at com.xxxxx.yyyyyyy.nsc.NSC.main(Unknown Source)

2011-08-21T07:08:27 Shutting down immediately
2011-08-21T07:08:27 shutting down Asset Group Service Executor…
2011-08-21T07:08:27 shutting down data warehouse service
2011-08-21T07:08:27 shutting down config manager
2011-08-21T07:08:27 Error shutting down database: java.sql.SQLException: No suitable driver
2011-08-21T07:08:27 shutting down logging