Java Community | Help. Code. Learn.•6mo ago

Java obfuscator issues

i am making an obfuscator for fun, trying to add dead code injection. its having issues with frame nodes. Issue is, i cant use COMPUTE_FRAMES, it gives me lots of issues with superclass types.

private InsnList generateDeadCodeBlock(MethodNode methodNode) {
        InsnList instructions = new InsnList();

        LabelNode deadCodeStart = new LabelNode();
        LabelNode deadCodeEnd = new LabelNode();

        // Start of dead code block
        instructions.add(deadCodeStart);
        instructions.add(new InsnNode(Opcodes.ICONST_0));
        instructions.add(new JumpInsnNode(Opcodes.IFNE, deadCodeEnd));

        // Add dead code
        instructions.add(generateSimpleDeadCode(methodNode));

        // End of dead code block
        instructions.add(deadCodeEnd);
        instructions.add(new FrameNode(Opcodes.F_APPEND, 1, new Object[]{Opcodes.INTEGER}, 0, null));

        return instructions;
    }


    private InsnList generateSimpleDeadCode(MethodNode methodNode) {
        InsnList instructions = new InsnList();
        int localVar = findAvailableLocalVar(methodNode);

        instructions.add(new InsnNode(Opcodes.ICONST_0));
        instructions.add(new VarInsnNode(Opcodes.ISTORE, localVar));
        instructions.add(new FrameNode(Opcodes.F_SAME, 0, new Object[]{Opcodes.INTEGER}, 0, null));
        instructions.add(new VarInsnNode(Opcodes.ILOAD, localVar));
        instructions.add(new InsnNode(Opcodes.ICONST_1));
        instructions.add(new InsnNode(Opcodes.IADD));
        instructions.add(new VarInsnNode(Opcodes.ISTORE, localVar));

        return instructions;
    }

private InsnList generateDeadCodeBlock(MethodNode methodNode) {
        InsnList instructions = new InsnList();

        LabelNode deadCodeStart = new LabelNode();
        LabelNode deadCodeEnd = new LabelNode();

        // Start of dead code block
        instructions.add(deadCodeStart);
        instructions.add(new InsnNode(Opcodes.ICONST_0));
        instructions.add(new JumpInsnNode(Opcodes.IFNE, deadCodeEnd));

        // Add dead code
        instructions.add(generateSimpleDeadCode(methodNode));

        // End of dead code block
        instructions.add(deadCodeEnd);
        instructions.add(new FrameNode(Opcodes.F_APPEND, 1, new Object[]{Opcodes.INTEGER}, 0, null));

        return instructions;
    }


    private InsnList generateSimpleDeadCode(MethodNode methodNode) {
        InsnList instructions = new InsnList();
        int localVar = findAvailableLocalVar(methodNode);

        instructions.add(new InsnNode(Opcodes.ICONST_0));
        instructions.add(new VarInsnNode(Opcodes.ISTORE, localVar));
        instructions.add(new FrameNode(Opcodes.F_SAME, 0, new Object[]{Opcodes.INTEGER}, 0, null));
        instructions.add(new VarInsnNode(Opcodes.ILOAD, localVar));
        instructions.add(new InsnNode(Opcodes.ICONST_1));
        instructions.add(new InsnNode(Opcodes.IADD));
        instructions.add(new VarInsnNode(Opcodes.ISTORE, localVar));

        return instructions;
    }

9 Replies

JavaBot•6mo ago

⌛ This post has been reserved for your question.

Hey @cvs0! Please use /close or the Close Post button above when your problem is solved. Please remember to follow the help guidelines. This post will be automatically marked as dormant after 300 minutes of inactivity.

TIP: Narrow down your issue to simple and precise questions to maximize the chance that others will reply in here.

cvs0OP•6mo ago

java.lang.IllegalStateException at org.objectweb.asm.MethodWriter.visitFrame(MethodWriter.java:793) at org.objectweb.asm.MethodVisitor.visitFrame(MethodVisitor.java:312) at org.objectweb.asm.commons.MethodRemapper.visitFrame(MethodRemapper.java:117) at org.objectweb.asm.tree.FrameNode.accept(FrameNode.java:147) at org.objectweb.asm.tree.InsnList.accept(InsnList.java:144) at org.objectweb.asm.tree.MethodNode.accept(MethodNode.java:749) at org.objectweb.asm.tree.MethodNode.accept(MethodNode.java:647) at org.objectweb.asm.tree.ClassNode.accept(ClassNode.java:468)

JavaBot•6mo ago