/*
Copyright (C) 2011-2012 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 Mono.Cecil;
using Mono.MyStuff;
using de4dot.blocks;
namespace de4dot.code.deobfuscators.CodeVeil {
public class DeobfuscatorInfo : DeobfuscatorInfoBase {
public const string THE_NAME = "CodeVeil";
public const string THE_TYPE = "cv";
const string DEFAULT_REGEX = @"!^[A-Za-z]{1,2}$&" + 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(),
});
}
protected override IEnumerable getOptionsInternal() {
return new List () {
};
}
}
class Deobfuscator : DeobfuscatorBase {
Options options;
string obfuscatorName = DeobfuscatorInfo.THE_NAME;
MainType mainType;
MethodsDecrypter methodsDecrypter;
ProxyDelegateFinder proxyDelegateFinder;
StringDecrypter stringDecrypter;
AssemblyResolver assemblyResolver;
TypeDefinition killType;
ResourceDecrypter resourceDecrypter;
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 obfuscatorName; }
}
public Deobfuscator(Options options)
: base(options) {
this.options = options;
StringFeatures = StringFeatures.AllowStaticDecryption | StringFeatures.AllowDynamicDecryption;
}
protected override int detectInternal() {
int val = 0;
int sum = toInt32(mainType.Detected) +
toInt32(methodsDecrypter.Detected) +
toInt32(stringDecrypter.Detected) +
toInt32(proxyDelegateFinder.Detected);
if (sum > 0)
val += 100 + 10 * (sum - 1);
if (killType != null)
val += 10;
return val;
}
protected override void scanForObfuscator() {
findKillType();
mainType = new MainType(module);
mainType.find();
proxyDelegateFinder = new ProxyDelegateFinder(module, mainType);
proxyDelegateFinder.findDelegateCreator();
methodsDecrypter = new MethodsDecrypter(mainType);
methodsDecrypter.find();
stringDecrypter = new StringDecrypter(module, mainType);
stringDecrypter.find();
var version = detectVersion();
if (!string.IsNullOrEmpty(version))
obfuscatorName = obfuscatorName + " " + version;
}
string detectVersion() {
if (mainType.Detected) {
switch (mainType.Version) {
case ObfuscatorVersion.Unknown:
return null;
case ObfuscatorVersion.V3:
return "3.x";
case ObfuscatorVersion.V4_0:
return "4.0";
case ObfuscatorVersion.V4_1:
return "4.1";
case ObfuscatorVersion.V5_0:
return "5.0";
default:
throw new ApplicationException("Unknown version");
}
}
return null;
}
void findKillType() {
foreach (var type in module.Types) {
if (type.FullName == "____KILL") {
killType = type;
break;
}
}
}
public override bool getDecryptedModule(ref byte[] newFileData, ref Dictionary dumpedMethods) {
if (!methodsDecrypter.Detected)
return false;
var fileData = DeobUtils.readModule(module);
if (!methodsDecrypter.decrypt(fileData, ref dumpedMethods))
return false;
newFileData = fileData;
return true;
}
public override IDeobfuscator moduleReloaded(ModuleDefinition module) {
var newOne = new Deobfuscator(options);
newOne.setModule(module);
newOne.mainType = new MainType(module, mainType);
newOne.methodsDecrypter = new MethodsDecrypter(mainType, methodsDecrypter);
newOne.stringDecrypter = new StringDecrypter(module, newOne.mainType, stringDecrypter);
newOne.proxyDelegateFinder = new ProxyDelegateFinder(module, newOne.mainType, proxyDelegateFinder);
newOne.killType = DeobUtils.lookup(module, killType, "Could not find KILL type");
return newOne;
}
public override void deobfuscateBegin() {
base.deobfuscateBegin();
addTypeToBeRemoved(killType, "KILL type");
mainType.initialize();
foreach (var initMethod in mainType.OtherInitMethods) {
addCctorInitCallToBeRemoved(initMethod);
addCtorInitCallToBeRemoved(initMethod);
}
if (Operations.DecryptStrings != OpDecryptString.None) {
stringDecrypter.initialize();
staticStringInliner.add(stringDecrypter.DecryptMethod, (method, args) => {
return stringDecrypter.decrypt((int)args[0]);
});
DeobfuscatedFile.stringDecryptersAdded();
addModuleCctorInitCallToBeRemoved(stringDecrypter.InitMethod);
addCallToBeRemoved(mainType.getInitStringDecrypterMethod(stringDecrypter.InitMethod), stringDecrypter.InitMethod);
}
assemblyResolver = new AssemblyResolver(module);
assemblyResolver.initialize();
dumpEmbeddedAssemblies();
removeTamperDetection();
proxyDelegateFinder.initialize();
proxyDelegateFinder.find();
resourceDecrypter = new ResourceDecrypter(module);
resourceDecrypter.initialize();
resourceDecrypter.decrypt();
if (resourceDecrypter.CanRemoveTypes) {
addTypeToBeRemoved(resourceDecrypter.ResourceFlagsType, "Obfuscator ResourceFlags type");
addTypeToBeRemoved(resourceDecrypter.ResType, "Obfuscator Res type");
addTypeToBeRemoved(resourceDecrypter.ResourceEnumeratorType, "Obfuscator ResourceEnumerator type");
addTypeToBeRemoved(resourceDecrypter.EncryptedResourceReaderType, "Obfuscator EncryptedResourceReader type");
addTypeToBeRemoved(resourceDecrypter.EncryptedResourceSetType, "Obfuscator EncryptedResourceSet type");
addTypeToBeRemoved(resourceDecrypter.EncryptedResourceStreamType, "Obfuscator EncryptedResourceStream type");
}
}
void removeTamperDetection() {
var tamperDetection = new TamperDetection(module, mainType);
tamperDetection.initialize();
foreach (var tamperDetectionMethod in tamperDetection.Methods)
addCctorInitCallToBeRemoved(tamperDetectionMethod);
addTypeToBeRemoved(tamperDetection.Type, "Tamper detection type");
}
void dumpEmbeddedAssemblies() {
foreach (var info in assemblyResolver.AssemblyInfos)
DeobfuscatedFile.createAssemblyFile(info.data, info.simpleName, info.extension);
addResourceToBeRemoved(assemblyResolver.BundleDataResource, "Embedded assemblies resource");
addResourceToBeRemoved(assemblyResolver.BundleXmlFileResource, "Embedded assemblies XML file resource");
addTypesToBeRemoved(assemblyResolver.BundleTypes, "Obfuscator assembly bundle types");
}
public override void deobfuscateMethodBegin(Blocks blocks) {
proxyDelegateFinder.deobfuscate(blocks);
base.deobfuscateMethodBegin(blocks);
}
public override void deobfuscateMethodEnd(Blocks blocks) {
mainType.removeInitCall(blocks);
resourceDecrypter.deobfuscate(blocks);
base.deobfuscateMethodEnd(blocks);
}
public override void deobfuscateEnd() {
bool canRemoveProxyTypes = proxyDelegateFinder.CanRemoveTypes;
if (CanRemoveStringDecrypterType)
addTypeToBeRemoved(stringDecrypter.Type, "String decrypter type");
if (!mainType.Detected) {
}
else if (mainType.Version >= ObfuscatorVersion.V5_0) {
if (!proxyDelegateFinder.FoundProxyType || canRemoveProxyTypes)
addTypeToBeRemoved(mainType.Type, "Main CV type");
}
else {
var type = mainType.Type;
if (!type.HasNestedTypes && !type.HasProperties && !type.HasEvents && !type.HasFields)
addTypeToBeRemoved(type, "Main CV type");
else {
foreach (var method in type.Methods)
addMethodToBeRemoved(method, "CV main type method");
}
}
removeTypesWithInvalidBaseTypes();
removeProxyDelegates(proxyDelegateFinder, canRemoveProxyTypes);
if (canRemoveProxyTypes) {
addTypeToBeRemoved(proxyDelegateFinder.IlGeneratorType, "Obfuscator proxy method ILGenerator type");
addTypeToBeRemoved(proxyDelegateFinder.FieldInfoType, "Obfuscator proxy method FieldInfo type");
addTypeToBeRemoved(proxyDelegateFinder.MethodInfoType, "Obfuscator proxy method MethodInfo type");
}
addMethodsToBeRemoved(InvalidMethodsFinder.findAll(module), "Anti-reflection method");
base.deobfuscateEnd();
}
public override IEnumerable getStringDecrypterMethods() {
var list = new List();
if (stringDecrypter.DecryptMethod != null)
list.Add(stringDecrypter.DecryptMethod.MetadataToken.ToInt32().ToString("X8"));
return list;
}
}
}