/*
Copyright (C) 2011-2014 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;
using System.Collections.Generic;
using dnlib.DotNet;
using dnlib.DotNet.Emit;
using de4dot.blocks;
namespace de4dot.code.deobfuscators.Spices_Net {
class ResourceNamesRestorer {
ModuleDefMD module;
TypeDef resourceManagerType;
TypeDef componentResourceManagerType;
MethodDefAndDeclaringTypeDict resourceManagerCtors = new MethodDefAndDeclaringTypeDict();
MethodDefAndDeclaringTypeDict componentManagerCtors = new MethodDefAndDeclaringTypeDict();
Dictionary callsResourceManager = new Dictionary();
public TypeDef ResourceManagerType {
get { return resourceManagerType; }
}
public TypeDef ComponentResourceManagerType {
get { return componentResourceManagerType; }
}
public ResourceNamesRestorer(ModuleDefMD module) {
this.module = module;
}
public void Find() {
foreach (var type in module.Types) {
if (IsResourceType(type, "System.Resources.ResourceManager"))
resourceManagerType = type;
else if (IsResourceType(type, "System.ComponentModel.ComponentResourceManager"))
componentResourceManagerType = type;
}
InitializeCtors(resourceManagerType, resourceManagerCtors);
InitializeCtors(componentResourceManagerType, componentManagerCtors);
}
void InitializeCtors(TypeDef manager, MethodDefAndDeclaringTypeDict ctors) {
if (manager == null)
return;
foreach (var ctor in manager.Methods) {
if (ctor.Name != ".ctor")
continue;
var newCtor = new MemberRefUser(module, ctor.Name, ctor.MethodSig.Clone(), manager.BaseType);
module.UpdateRowId(newCtor);
ctors.Add(ctor, newCtor);
}
}
static bool IsResourceType(TypeDef type, string baseTypeName) {
if (type.BaseType == null || type.BaseType.FullName != baseTypeName)
return false;
if (type.HasProperties || type.HasEvents || type.HasFields)
return false;
if (type.Interfaces.Count > 0)
return false;
var method = type.FindMethod("GetResourceFileName");
if (!DotNetUtils.IsMethod(method, "System.String", "(System.Globalization.CultureInfo)"))
return false;
return true;
}
class ResourceDictionary {
struct Key {
public readonly uint hash;
public readonly string ns;
public Key(uint hash, string ns) {
this.hash = hash;
this.ns = ns;
}
public override int GetHashCode() {
return (int)(hash ^ ns.GetHashCode());
}
public override bool Equals(object obj) {
if (!(obj is Key))
return false;
var other = (Key)obj;
return hash == other.hash &&
ns == other.ns;
}
public override string ToString() {
if (ns == string.Empty)
return string.Format("{0}", hash);
return string.Format("{0}.{1}", ns, hash);
}
}
Dictionary resources = new Dictionary();
public int Count {
get { return resources.Count; }
}
public bool Add(Resource resource) {
var name = resource.Name.String;
int index = name.LastIndexOf('.');
string ext;
if (index < 0)
ext = name;
else
ext = name.Substring(index + 1);
uint extNum;
if (!uint.TryParse(ext, out extNum))
return false;
var ns = index < 0 ? string.Empty : name.Substring(0, index);
resources.Add(new Key(extNum, ns), resource);
return true;
}
public Resource GetAndRemove(uint hash, string ns) {
var key = new Key(hash, ns);
Resource resource;
if (resources.TryGetValue(key, out resource))
resources.Remove(key);
return resource;
}
}
public void RenameResources() {
if (resourceManagerType == null && componentResourceManagerType == null)
return;
var rsrcDict = new ResourceDictionary();
foreach (var resource in module.Resources)
rsrcDict.Add(resource);
if (module.Assembly != null)
Rename(rsrcDict, "", module.Assembly.Name + ".g");
foreach (var type in callsResourceManager.Keys)
Rename(rsrcDict, type);
if (rsrcDict.Count != 0) {
foreach (var type in module.GetTypes()) {
if (rsrcDict.Count == 0)
break;
if (!IsWinFormType(type))
continue;
Rename(rsrcDict, type);
}
}
if (rsrcDict.Count != 0) {
foreach (var type in module.GetTypes()) {
if (rsrcDict.Count == 0)
break;
Rename(rsrcDict, type);
}
}
if (rsrcDict.Count != 0)
Logger.e("Couldn't restore all renamed resource names");
}
static bool IsWinFormType(TypeDef type) {
for (int i = 0; i < 100; i++) {
var baseType = type.BaseType;
if (baseType == null)
break;
if (baseType.FullName == "System.Object" ||
baseType.FullName == "System.ValueType")
return false;
// Speed up common cases
if (baseType.FullName == "System.Windows.Forms.Control" ||
baseType.FullName == "System.Windows.Forms.Form" ||
baseType.FullName == "System.Windows.Forms.UserControl")
return true;
var resolvedBaseType = baseType.ResolveTypeDef();
if (resolvedBaseType == null)
break;
type = resolvedBaseType;
}
return false;
}
static bool Rename(ResourceDictionary rsrcDict, TypeDef type) {
if (!IsWinFormType(type) && Rename(rsrcDict, "", type.FullName))
return true;
return Rename(rsrcDict, type.Namespace, type.Name);
}
static bool Rename(ResourceDictionary rsrcDict, string ns, string name) {
var resourceName = name + ".resources";
uint hash = GetResourceHash(resourceName);
var resource = rsrcDict.GetAndRemove(hash, ns);
if (resource == null)
return false;
int index = resource.Name.String.LastIndexOf('.');
string resourceNamespace, newName;
if (index < 0) {
resourceNamespace = "";
newName = resourceName;
}
else {
resourceNamespace = resource.Name.String.Substring(0, index);
newName = resourceNamespace + "." + resourceName;
}
if (resourceNamespace != ns)
throw new ApplicationException("Invalid resource namespace");
Logger.v("Restoring resource name: '{0}' => '{1}'",
Utils.RemoveNewlines(resource.Name),
Utils.RemoveNewlines(newName));
resource.Name = newName;
return true;
}
static uint GetResourceHash(string name) {
uint hash = 0;
foreach (var c in name)
hash = Ror(hash ^ c, 1);
return hash;
}
static uint Ror(uint val, int n) {
return (val << (32 - n)) + (val >> n);
}
public void Deobfuscate(Blocks blocks) {
if (resourceManagerType == null && componentResourceManagerType == null)
return;
foreach (var block in blocks.MethodBlocks.GetAllBlocks()) {
var instrs = block.Instructions;
for (int i = 0; i < instrs.Count; i++) {
var instr = instrs[i];
if (instr.OpCode.Code != Code.Newobj)
continue;
var ctor = instr.Operand as IMethod;
if (ctor == null)
continue;
var newCtor = resourceManagerCtors.Find(ctor);
if (newCtor == null)
newCtor = componentManagerCtors.Find(ctor);
if (newCtor == null)
continue;
instr.Operand = newCtor;
callsResourceManager[blocks.Method.DeclaringType] = true;
}
}
}
}
}