/*
Copyright (C) 2011-2013 de4dot@gmail.com
This file is part of de4dot.
de4dot is free software: you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation, either version 3 of the License, or
(at your option) any later version.
de4dot is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
GNU General Public License for more details.
You should have received a copy of the GNU General Public License
along with de4dot. If not, see .
*/
using System.Collections.Generic;
using dnlib.DotNet;
namespace de4dot.code.deobfuscators.Xenocode {
public class DeobfuscatorInfo : DeobfuscatorInfoBase {
public const string THE_NAME = "Xenocode";
public const string THE_TYPE = "xc";
const string DEFAULT_REGEX = @"!^[oO01l]{4,}$&!^(get_|set_|add_|remove_|_)?[x_][a-f0-9]{16,}$&" + DeobfuscatorBase.DEFAULT_VALID_NAME_REGEX;
public DeobfuscatorInfo()
: base(DEFAULT_REGEX) {
}
public override string Name {
get { return THE_NAME; }
}
public override string Type {
get { return THE_TYPE; }
}
public override IDeobfuscator createDeobfuscator() {
return new Deobfuscator(new Deobfuscator.Options {
ValidNameRegex = validNameRegex.get(),
});
}
}
class Deobfuscator : DeobfuscatorBase {
bool foundXenocodeAttribute = false;
StringDecrypter stringDecrypter;
internal class Options : OptionsBase {
}
public override string Type {
get { return DeobfuscatorInfo.THE_TYPE; }
}
public override string TypeLong {
get { return DeobfuscatorInfo.THE_NAME; }
}
public override string Name {
get { return TypeLong; }
}
public Deobfuscator(Options options)
: base(options) {
}
protected override int detectInternal() {
int val = 0;
if (stringDecrypter.Detected)
val += 100;
if (foundXenocodeAttribute)
val += 10;
return val;
}
protected override void scanForObfuscator() {
findXenocodeAttribute();
stringDecrypter = new StringDecrypter(module);
stringDecrypter.find();
}
void findXenocodeAttribute() {
foreach (var type in module.Types) {
switch (type.FullName) {
case "Xenocode.Client.Attributes.AssemblyAttributes.ProcessedByXenocode":
case "Xenocode.Client.Attributes.AssemblyAttributes.SuppressDisassembly":
case "Xenocode.User.Attributes.AssemblyAttributes.ProcessedByXenoCode":
case "Xenocode.User.Attributes.AssemblyAttributes.SuppressDisassembly":
addAttributeToBeRemoved(type, "Obfuscator attribute");
foundXenocodeAttribute = true;
break;
}
}
}
public override void deobfuscateBegin() {
base.deobfuscateBegin();
staticStringInliner.add(stringDecrypter.Method, (method, gim, args) => stringDecrypter.decrypt((string)args[0], (int)args[1]));
DeobfuscatedFile.stringDecryptersAdded();
}
public override void deobfuscateEnd() {
if (CanRemoveStringDecrypterType)
addTypeToBeRemoved(stringDecrypter.Type, "String decrypter type");
var obfType = findTypeWithThousandsOfMethods();
if (obfType != null)
addTypeToBeRemoved(obfType, "Obfuscator type with thousands of empty methods");
removeInvalidAttributes(module);
removeInvalidAttributes(module.Assembly);
base.deobfuscateEnd();
}
TypeDef findTypeWithThousandsOfMethods() {
foreach (var type in module.Types) {
if (isTypeWithThousandsOfMethods(type))
return type;
}
return null;
}
bool isTypeWithThousandsOfMethods(TypeDef type) {
if (!type.IsNotPublic)
return false;
if (type.HasFields || type.HasEvents || type.HasProperties)
return false;
if (type.Methods.Count < 100)
return false;
foreach (var method in type.Methods) {
if (method.IsStaticConstructor)
return false;
if (method.IsConstructor) {
if (method.MethodSig.GetParamCount() != 0)
return false;
continue;
}
if (!method.IsPrivate || method.IsStatic)
return false;
if (method.Body == null)
return false;
if (method.Body.Instructions.Count != 1)
return false;
}
return true;
}
// Remove the attribute Xenocode adds that has an invalid ctor
void removeInvalidAttributes(IHasCustomAttribute hca) {
if (!CanRemoveTypes)
return;
if (hca == null)
return;
for (int i = hca.CustomAttributes.Count - 1; i >= 0; i--) {
var ca = hca.CustomAttributes[i];
if (ca.Constructor == null)
hca.CustomAttributes.RemoveAt(i);
}
}
public override IEnumerable getStringDecrypterMethods() {
var list = new List();
if (stringDecrypter.Method != null)
list.Add(stringDecrypter.Method.MDToken.ToInt32());
return list;
}
}
}