Deobfuscate Java, mass rename classes in jar

Question

I have a jar in which the class files have been obfuscated. I'm happy to manually deobfuscate it, but the problem is that the class names are so long that windows won't save them to disk. Is there any tool that will take in a jar and rename all classes, and preferably also methods and fields?

Also, do not give answers saying that there is no good reason for decompiling etc. as they neither contribute any useful information to the community nor hold true. In my case, I'm checking for a security problem in this particular application.

Answer 1

I would probably use a deobfuscator in a virtual machine and some linux distro.
After the deobfuscation you can pack the files in a zip / jar and continue development in your Windows environment.

I would recommend VirtualBox with Ubuntu.

Answer 2

The best way to approach this with modern tools would be to use Proguard to simply class/member names. Then using a tool such as Enigma to manually create mappings.

I'm also writing a program in Java-ASM that takes mappings and converts them into a runnable Jar. Engima by itself doesn't fair to well when exporting.