Example usage for org.objectweb.asm.tree InsnList remove

Introduction

In this page you can find the example usage for org.objectweb.asm.tree InsnList remove.

Prototype

public void remove(final AbstractInsnNode insnNode)

Source Link

Document

Removes the given instruction from this list.

Usage

From source file:the.bytecode.club.bytecodeviewer.plugin.preinstalled.AllatoriStringDecrypter.java

License:Open Source License

public void scanMethodNode(ClassNode classNode, MethodNode methodNode) throws Exception {
    InsnList iList = methodNode.instructions;

    log("Scanning method " + methodNode.name + " of " + classNode.name);

    LdcInsnNode laststringldconstack = null;
    for (AbstractInsnNode i : iList.toArray()) {
        if (i instanceof LdcInsnNode) {
            LdcInsnNode ldci = (LdcInsnNode) i;
            if (ldci.cst instanceof String) {
                laststringldconstack = ldci;
            }//from  w w w .ja  v  a  2 s  .  co m
            continue;
        } else if (i instanceof MethodInsnNode) {
            MethodInsnNode methodi = (MethodInsnNode) i;

            if (laststringldconstack != null && methodi.opcode() == 0xb8) { // Decryption is always a static call - 0xb8 - invokestatic
                String decrypterclassname = methodi.owner;
                String decryptermethodname = methodi.name;

                if (decrypterclassname.contains("$")) { // Decrypter is always a static method of other class's inner class
                    byte[] decrypterFileContents = BytecodeViewer
                            .getFileContents(decrypterclassname + ".class");

                    // We have to create new node for editing
                    // Also, one decrypter method could be used for multiple methods in code, what gives us only part of string decrypted
                    ClassNode decrypterclassnode = JarUtils.getNode(decrypterFileContents);

                    if (decrypterclassnode != null) {
                        MethodNode decryptermethodnode = null;
                        for (Object uncasted : decrypterclassnode.methods) {
                            if (((MethodNode) uncasted).name.equals(decryptermethodname)) {
                                decryptermethodnode = (MethodNode) uncasted;
                            }
                        }
                        if (decryptermethodnode != null) {

                            String keyString = (getConstantPoolSize(classNode.name) + classNode.name
                                    + methodNode.name + getConstantPoolSize(classNode.name));

                            int newHashCode = keyString.hashCode();

                            scanDecrypter(decryptermethodnode, newHashCode);

                            try {
                                System.out.println("loading " + decrypterclassname);

                                List<Class<?>> decrypterclasslist = the.bytecode.club.bytecodeviewer.api.BytecodeViewer
                                        .loadClassesIntoClassLoader(new ArrayList<ClassNode>(
                                                Arrays.asList(new ClassNode[] { decrypterclassnode })));

                                String decrypted = invokeDecrypter(decrypterclasslist.get(0),
                                        decryptermethodname, (String) laststringldconstack.cst);

                                if (decrypted != null) {
                                    log("Succesfully invoked decrypter method: " + decrypted);
                                    laststringldconstack.cst = decrypted;
                                    iList.remove(methodi);
                                }
                            } catch (IndexOutOfBoundsException | ClassNotFoundException | IOException e) {
                                e.printStackTrace();
                                log("Could not load decrypter class: " + decrypterclassname);
                            }

                        } else {
                            log("Could not find decrypter method (" + decryptermethodname + ") of class "
                                    + decrypterclassname);
                        }
                    } else {
                        log("Could not find decrypter ClassNode of class " + decrypterclassname);
                    }
                }
            }

        } else if (i instanceof InvokeDynamicInsnNode) {
            InvokeDynamicInsnNode methodi = (InvokeDynamicInsnNode) i;
            if (methodi.opcode() == 0xba) {
                // TODO: Safe-reflection deobfuscator here
                // Allatori replaces invokeinterface and invokestatic with invokedynamic

                //log(methodi.bsm.getOwner()+" dot "+methodi.bsm.getName());
                //iList.set(methodi, new MethodInsnNode(0xb8, methodi.bsm.getOwner(), methodi.bsm.getName(), methodi.bsm.getDesc(), false));

            }

        }
        laststringldconstack = null;
    }
}

From source file:the.bytecode.club.bytecodeviewer.plugin.preinstalled.AllatoriStringDecrypter.java

License:Open Source License

private boolean scanDecrypter(MethodNode decryptermethodnode, int newHashCode) {
    InsnList iList = decryptermethodnode.instructions;

    AbstractInsnNode insn = null, removeInsn = null;
    for (AbstractInsnNode i : iList.toArray()) {
        if (i instanceof MethodInsnNode) {
            MethodInsnNode methodi = ((MethodInsnNode) i);
            if ("currentThread".equals(methodi.name)) { // find code form this instruction
                insn = i;//from   www  .ja v a2  s  .c o  m
                break;
            }

        }

    }
    if (insn == null) {
        return false;
    }

    while (insn != null) {
        if (insn instanceof MethodInsnNode) {
            MethodInsnNode methodi = ((MethodInsnNode) insn);
            if ("hashCode".equals(methodi.name)) { // to this instruction
                break;
            }
        }
        removeInsn = insn;
        insn = insn.getNext();
        iList.remove(removeInsn); // and remove it
    }
    if (insn == null)
        return false;
    iList.set(insn, new LdcInsnNode(newHashCode)); // then replace it with pre-computed key LDC
    return true;
}