paimonqwq / skidfuscator-ir

Strongly referenced bytecode ir for Java

skidfuscator-ir

Imagine if you could rename a class and its invokers by doing klass.setName(<name). Well now u can.

Usage

Add it in your root build.gradle at the end of repositories:

	allprojects {
		repositories {
			...
			maven { url 'https://jitpack.io' }
		}
	}

Step 2. Add the dependency

	dependencies {
	        implementation 'com.github.skidfuscatordev:skidfuscator-ir:master-SNAPSHOT'
	}

Then, to begin using it, create a hierarchy as follows:

final Map<String, ClassNode> classes = new HashMap();
// Your class loading logic here

final SkidLibraryHierarchy hierarchy = new SkidLibraryHierarchy();
hierarchy.resolveClasses(classes);

Iterating wrapped classes

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You can iterate all application classes by using

for (final KlassNode node : hierarchy.iterateKlasses()) {
    node.setName("Omg" + node.getName());
}

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Finding a class

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You can find a class of the name formatted as "my/searched/Class" by using

final KlassNode node = hierarchy.resolveClass("my/searched/Class");

If the class does not exist, if configured, an "UnresolvedKlassNode" will be generated. If you seek to not generate a phantom class, please instead use the deprecated hierarchy#findClass until I finish writing the config system.

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Modifying the bytecode

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You can access and modify the bytecode of a class by doing the following:

final KlassNode node = hierarchy.resolveClass("my/searched/Class");

for (final FunctionNode method : node.getMethods()) {
    final InstructionList bytecode = method.getInstructionList();
    bytecode.add(new SimpleInsn(hierarchy, new InsnNode(Opcodes.NOP)));
}

The following nodes are wrapped:

• FieldInsnNode --> FieldInsn
• FrameNode --> FrameInsn
• IincInsnNode --> IincInsn
• IntInsnNode --> IntInsn
• InvokeDynamicInsnNode --> InvokeDynamicInsn
• MethodInsnNode --> InvokeInsn
• JumpInsnNode --> JumpInsn
• LabelNode --> LabelInsn
• LdcInsnNode --> LdcInsn
• LineNumberNode --> LineNumberInsn
• LookupSwitchInsnNode --> LookupSwitchInsn
• TableSwitchInsnNode --> TableSwitchNode
• MultiANewArrayInsnNode --> MultiANewArrayInsn
• InsnNode --> SimpleInsn
• TypeInsnNode --> TypeInsn
• VarInsnNode --> VarInsn

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Preventing further changes

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With skidfuscator-ir, you can lock changes on a class. This will effectively prevent any further changes to the class if you wish to inspect a class and set it as a library post-resolving it. Practical for analysers wishing to debug what's changing what.

final KlassNode node = hierarchy.resolveClass("my/searched/Class");
node.lock(); // Locks a class

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Todo

• Finish all insn nodes
• Create test suite
• Add support for fields
• Add support for annotation
• signatures
• mapper for types
• mapper for annotations
• mapper for annotation method linking