Main
interface of CafeBabe
Description
The main goal of CafeBabe
project is to offer for developers complete and
convenient suite of tools that operate directly with
bytecodes.
The core of
CafeBabe project is ClassFile
library that allows reading, modification and
writing of bytecodes.
Main features of CafeBabe project are:
- program represents bytecodes
"as is" - following the class
file format specification: magic number,
minor and major version, constant pool, access
flags, this class, super class, interfaces,
fields, methods and class attributes;
- program can read class files
directly from archive (*.zip or
*.jar) and it interprets them as directories,
thereby you can travel inside archive for
selecting desired file;
- program contains abilities for searching
string inside bytecode;
- user can edit
information inside constant pool (UTF8-string);
- ability to remove some
optional information from bytecodes: inside
methods body, source file attribute, unknown
attributes;
- ability to perform migration
of bytecodes disposed inside package from old to
new namespace;
- ability to perform obfuscation
of bytecodes disposed inside packages;
- ability to show/hide partitions of
classfile.
- user can use this program as a tutorial
- tooltips will explain to user what each byte
(short, integer) inside bytecode means;
- user can quickly change its own
location among installed classes and observe
hierarchy tree (see Class-Hound Service);
Solving
tasks: today and future
CafeBabe will be useful for solving the
following tasks:
1. Tutorial task
Any new tool should teach user --
otherwise it becomes meaningless tool. CafeBabe's main
window represents bytecode structure directly, following
the class file format specification.
CafeBabe supports tutorial mode -- in
this case user can see tooltips for any branch/leaf/cell
of main tree-table. Tooltips discover sense of each
byte/short/int inside bytecode.
You can receive another tutorial issue
playing with Class-Hound service. Like a
wise dog, this service is quickly talking you
all about installed archives and including with these
archives classes, it will show memberships (list of
fields and methods) and hierarchy tree for selected class
and by your request will load selected class to main
tree-table window.
Class-Hound service has a great
educational importance because it proposes live
information about really existing classes, fields and
methods vs. information, presented in documentation. Also
this service produces short information without any extra
unwanted info.
2. Optimization task
You can optimize your product from
command line (javac -O or javac -g:none) but for that you
must recompile whole project. Sometimes it can be
undesired solution - f.e. you have no sources. Just run strip
task from CafeBabe (for selected file or for
group of files) and select what do you want to remove:
"SourceFile" attribute, unknown attribute or
debugging information inside method body. Some tools add
own labels to bytecode when processing it (f.e.
SourceGuard from 4thpass) -- try to remove unwished tags.
Other task for optimization is to find
all methods that can be declared as final and set up
method modifier to final value on bytecode
level. We can name such task as finalize task and
it will be realized in nearest future.
3. Hacker task
CafeBabe gives you an ability to edit
constant pool entries - now UTF8 only. It is not limit --
only author's flavour. I can add an ability to edit other
types of entries, but I think it is meaningless - all
they ultimately refer to UTF8 strings.
4. Obfuscation task
User have an ability to
protect application's codes from easy understanding for
outer developers. CafeBabe analyzes proposed classes,
find dependencies between them and solves obfuscation
task. You can select what items you want to obfuscate:
packages, classes, fields or methods. In addition you can
move all classes from different packages to anonymous
package. This approach is greatly decreases size of
project.
5. Migration Task
If you have Swing program (bytecodes
only), written with old namespace conventions
(com.sun.java.swing) and now you work with new namespace
conventions (javax.swing), migration tool will help you.
Just run migration task from CafeBabe (for selected file
or for group of files) and you'll receive desired
results.
Author think that migration is a sort
of obfuscation when you don't change names for classes,
fields and methods, only for packages by using
information from specified migration table. Exactly this
way is realized in Cafebabe.
Note: this task works on bytecode
level, thereby you can solve such task without a presence
of sources.
6. Creational task - in future
User will have an ability to create new
bytecodes "from scratch", add new fields,
methods, attributes, constant pool entries and test
created class. It can be useful for persons who like VM
but hate Java :-).
7. Decompilation task - in future
User will have an ability to decompile
entire class or selected method only.
Class-Hound Service in
action...
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