de4dot-cex/de4dot.code/deobfuscators/dotNET_Reactor/v4/Deobfuscator.cs
2012-01-07 19:14:15 +01:00

601 lines
20 KiB
C#

/*
Copyright (C) 2011 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 <http://www.gnu.org/licenses/>.
*/
using System;
using System.Collections.Generic;
using System.IO;
using System.Text.RegularExpressions;
using Mono.Cecil;
using Mono.Cecil.Cil;
using Mono.MyStuff;
using de4dot.blocks;
using de4dot.code.PE;
namespace de4dot.code.deobfuscators.dotNET_Reactor.v4 {
public class DeobfuscatorInfo : DeobfuscatorInfoBase {
public const string THE_NAME = ".NET Reactor";
public const string THE_TYPE = "dr4";
const string DEFAULT_REGEX = DeobfuscatorBase.DEFAULT_VALID_NAME_REGEX;
BoolOption decryptMethods;
BoolOption decryptBools;
BoolOption restoreTypes;
BoolOption inlineMethods;
BoolOption removeInlinedMethods;
BoolOption dumpEmbeddedAssemblies;
BoolOption decryptResources;
BoolOption removeNamespaces;
BoolOption removeAntiStrongName;
NoArgOption dumpNativeMethods;
public DeobfuscatorInfo()
: base(DEFAULT_REGEX) {
decryptMethods = new BoolOption(null, makeArgName("methods"), "Decrypt methods", true);
decryptBools = new BoolOption(null, makeArgName("bools"), "Decrypt booleans", true);
restoreTypes = new BoolOption(null, makeArgName("types"), "Restore types (object -> real type)", true);
inlineMethods = new BoolOption(null, makeArgName("inline"), "Inline short methods", true);
removeInlinedMethods = new BoolOption(null, makeArgName("remove-inlined"), "Remove inlined methods", true);
dumpEmbeddedAssemblies = new BoolOption(null, makeArgName("embedded"), "Dump embedded assemblies", true);
decryptResources = new BoolOption(null, makeArgName("rsrc"), "Decrypt resources", true);
removeNamespaces = new BoolOption(null, makeArgName("ns1"), "Clear namespace if there's only one class in it", true);
removeAntiStrongName = new BoolOption(null, makeArgName("sn"), "Remove anti strong name code", true);
dumpNativeMethods = new NoArgOption(null, makeArgName("dump-native"), "Dump native methods to filename.dll.native");
}
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(),
DecryptMethods = decryptMethods.get(),
DecryptBools = decryptBools.get(),
RestoreTypes = restoreTypes.get(),
InlineMethods = inlineMethods.get(),
RemoveInlinedMethods = removeInlinedMethods.get(),
DumpEmbeddedAssemblies = dumpEmbeddedAssemblies.get(),
DecryptResources = decryptResources.get(),
RemoveNamespaces = removeNamespaces.get(),
RemoveAntiStrongName = removeAntiStrongName.get(),
DumpNativeMethods = dumpNativeMethods.get(),
});
}
protected override IEnumerable<Option> getOptionsInternal() {
return new List<Option>() {
decryptMethods,
decryptBools,
restoreTypes,
inlineMethods,
removeInlinedMethods,
dumpEmbeddedAssemblies,
decryptResources,
removeNamespaces,
removeAntiStrongName,
dumpNativeMethods,
};
}
}
class Deobfuscator : DeobfuscatorBase {
Options options;
string obfuscatorName = DeobfuscatorInfo.THE_NAME;
PeImage peImage;
byte[] fileData;
MethodsDecrypter methodsDecrypter;
StringDecrypter stringDecrypter;
BooleanDecrypter booleanDecrypter;
BooleanValueInliner booleanValueInliner;
MetadataTokenObfuscator metadataTokenObfuscator;
AssemblyResolver assemblyResolver;
ResourceResolver resourceResolver;
AntiStrongName antiStrongname;
EmptyClass emptyClass;
bool unpackedNativeFile = false;
bool canRemoveDecrypterType = true;
bool startedDeobfuscating = false;
internal class Options : OptionsBase {
public bool DecryptMethods { get; set; }
public bool DecryptBools { get; set; }
public bool RestoreTypes { get; set; }
public bool InlineMethods { get; set; }
public bool RemoveInlinedMethods { get; set; }
public bool DumpEmbeddedAssemblies { get; set; }
public bool DecryptResources { get; set; }
public bool RemoveNamespaces { get; set; }
public bool RemoveAntiStrongName { get; set; }
public bool DumpNativeMethods { get; set; }
}
public override string Type {
get { return DeobfuscatorInfo.THE_TYPE; }
}
public override string TypeLong {
get { return DeobfuscatorInfo.THE_NAME + " 4.x"; }
}
public override string Name {
get { return obfuscatorName; }
}
public override bool CanInlineMethods {
get { return startedDeobfuscating ? options.InlineMethods : true; }
}
public Deobfuscator(Options options)
: base(options) {
this.options = options;
if (options.RemoveNamespaces)
this.RenamingOptions |= RenamingOptions.RemoveNamespaceIfOneType;
else
this.RenamingOptions &= ~RenamingOptions.RemoveNamespaceIfOneType;
}
public override byte[] unpackNativeFile(PeImage peImage) {
var data = new NativeImageUnpacker(peImage).unpack();
if (data == null)
return null;
unpackedNativeFile = true;
ModuleBytes = data;
return data;
}
public override void init(ModuleDefinition module) {
base.init(module);
}
static Regex isRandomName = new Regex(@"^[A-Z]{30,40}$");
static Regex isRandomNameMembers = new Regex(@"^[a-zA-Z0-9]{9,11}$"); // methods, fields, props, events
static Regex isRandomNameTypes = new Regex(@"^[a-zA-Z0-9]{18,19}(?:`\d+)?$"); // types, namespaces
bool checkValidName(string name, Regex regex) {
if (isRandomName.IsMatch(name))
return false;
if (regex.IsMatch(name)) {
if (RandomNameChecker.isRandom(name))
return false;
if (!RandomNameChecker.isNonRandom(name))
return false;
}
return checkValidName(name);
}
public override bool isValidNamespaceName(string ns) {
if (ns == null)
return false;
if (ns.Contains("."))
return base.isValidNamespaceName(ns);
return checkValidName(ns, isRandomNameTypes);
}
public override bool isValidTypeName(string name) {
return name != null && checkValidName(name, isRandomNameTypes);
}
public override bool isValidMethodName(string name) {
return name != null && checkValidName(name, isRandomNameMembers);
}
public override bool isValidPropertyName(string name) {
return name != null && checkValidName(name, isRandomNameMembers);
}
public override bool isValidEventName(string name) {
return name != null && checkValidName(name, isRandomNameMembers);
}
public override bool isValidFieldName(string name) {
return name != null && checkValidName(name, isRandomNameMembers);
}
public override bool isValidGenericParamName(string name) {
return name != null && checkValidName(name, isRandomNameMembers);
}
public override bool isValidMethodArgName(string name) {
return name != null && checkValidName(name, isRandomNameMembers);
}
protected override int detectInternal() {
int val = 0;
int sum = toInt32(methodsDecrypter.Detected) +
toInt32(stringDecrypter.Detected) +
toInt32(booleanDecrypter.Detected) +
toInt32(assemblyResolver.Detected) +
toInt32(resourceResolver.Detected);
if (sum > 0)
val += 100 + 10 * (sum - 1);
if (sum == 0) {
if (hasMetadataStream("#GUlD") && hasMetadataStream("#Blop"))
val += 10;
}
return val;
}
protected override void scanForObfuscator() {
methodsDecrypter = new MethodsDecrypter(module);
methodsDecrypter.find();
stringDecrypter = new StringDecrypter(module);
stringDecrypter.find(DeobfuscatedFile);
booleanDecrypter = new BooleanDecrypter(module);
booleanDecrypter.find();
assemblyResolver = new AssemblyResolver(module);
assemblyResolver.find(DeobfuscatedFile);
obfuscatorName = detectVersion();
if (unpackedNativeFile)
obfuscatorName += " (native)";
resourceResolver = new ResourceResolver(module);
resourceResolver.find(DeobfuscatedFile);
}
string detectVersion() {
/*
Methods decrypter locals (not showing its own types):
3.7.0.3:
"System.Byte[]"
"System.Int32"
"System.Int32[]"
"System.IntPtr"
"System.IO.BinaryReader"
"System.IO.MemoryStream"
"System.Object"
"System.Reflection.Assembly"
"System.Security.Cryptography.CryptoStream"
"System.Security.Cryptography.ICryptoTransform"
"System.Security.Cryptography.RijndaelManaged"
"System.String"
3.9.8.0:
- "System.Int32[]"
+ "System.Diagnostics.StackFrame"
4.0.0.0: (jitter)
- "System.Diagnostics.StackFrame"
- "System.Object"
+ "System.Boolean"
+ "System.Collections.IEnumerator"
+ "System.Delegate"
+ "System.Diagnostics.Process"
+ "System.Diagnostics.ProcessModule"
+ "System.Diagnostics.ProcessModuleCollection"
+ "System.IDisposable"
+ "System.Int64"
+ "System.UInt32"
+ "System.UInt64"
4.1.0.0: (jitter)
+ "System.Reflection.Assembly"
4.3.1.0: (jitter)
+ "System.Byte&"
*/
LocalTypes localTypes;
int minVer = -1;
foreach (var info in stringDecrypter.DecrypterInfos) {
if (info.key == null)
continue;
localTypes = new LocalTypes(info.method);
if (!localTypes.exists("System.IntPtr"))
return DeobfuscatorInfo.THE_NAME + " <= 3.7";
minVer = 3800;
break;
}
if (methodsDecrypter.Method == null) {
if (minVer >= 3800)
return DeobfuscatorInfo.THE_NAME + " >= 3.8";
return DeobfuscatorInfo.THE_NAME;
}
localTypes = new LocalTypes(methodsDecrypter.Method);
if (localTypes.exists("System.Int32[]")) {
if (minVer >= 3800)
return DeobfuscatorInfo.THE_NAME + " 3.8.4.1 - 3.9.0.1";
return DeobfuscatorInfo.THE_NAME + " <= 3.9.0.1";
}
if (!localTypes.exists("System.Diagnostics.Process")) { // If < 4.0
if (localTypes.exists("System.Diagnostics.StackFrame"))
return DeobfuscatorInfo.THE_NAME + " 3.9.8.0";
}
var compileMethod = MethodsDecrypter.findDnrCompileMethod(methodsDecrypter.Method.DeclaringType);
if (compileMethod == null)
return DeobfuscatorInfo.THE_NAME + " < 4.0";
DeobfuscatedFile.deobfuscate(compileMethod);
bool compileMethodHasConstant_0x70000000 = DotNetUtils.findLdcI4Constant(compileMethod, 0x70000000); // 4.0-4.1
DeobfuscatedFile.deobfuscate(methodsDecrypter.Method);
bool hasCorEnableProfilingString = findString(methodsDecrypter.Method, "Cor_Enable_Profiling"); // 4.1-4.4
if (compileMethodHasConstant_0x70000000) {
if (hasCorEnableProfilingString)
return DeobfuscatorInfo.THE_NAME + " 4.1";
return DeobfuscatorInfo.THE_NAME + " 4.0";
}
if (!hasCorEnableProfilingString)
return DeobfuscatorInfo.THE_NAME;
// 4.2-4.4
if (!localTypes.exists("System.Byte&"))
return DeobfuscatorInfo.THE_NAME + " 4.2";
localTypes = new LocalTypes(compileMethod);
if (localTypes.exists("System.Object"))
return DeobfuscatorInfo.THE_NAME + " 4.4";
return DeobfuscatorInfo.THE_NAME + " 4.3";
}
static bool findString(MethodDefinition method, string s) {
foreach (var cs in DotNetUtils.getCodeStrings(method)) {
if (cs == s)
return true;
}
return false;
}
public override bool getDecryptedModule(ref byte[] newFileData, ref Dictionary<uint, DumpedMethod> dumpedMethods) {
fileData = ModuleBytes ?? DeobUtils.readModule(module);
peImage = new PeImage(fileData);
if (!options.DecryptMethods)
return false;
var tokenToNativeCode = new Dictionary<uint,byte[]>();
if (!methodsDecrypter.decrypt(peImage, DeobfuscatedFile, ref dumpedMethods, tokenToNativeCode))
return false;
if (options.DumpNativeMethods) {
using (var fileStream = new FileStream(module.FullyQualifiedName + ".native", FileMode.Create, FileAccess.Write, FileShare.Read)) {
var sortedTokens = new List<uint>(tokenToNativeCode.Keys);
sortedTokens.Sort();
var writer = new BinaryWriter(fileStream);
var nops = new byte[] { 0x90, 0x90, 0x90, 0x90 };
foreach (var token in sortedTokens) {
writer.Write((byte)0xB8);
writer.Write(token);
writer.Write(tokenToNativeCode[token]);
writer.Write(nops);
}
}
}
newFileData = fileData;
return true;
}
public override IDeobfuscator moduleReloaded(ModuleDefinition module) {
var newOne = new Deobfuscator(options);
newOne.setModule(module);
newOne.fileData = fileData;
newOne.peImage = new PeImage(fileData);
newOne.methodsDecrypter = new MethodsDecrypter(module, methodsDecrypter);
newOne.stringDecrypter = new StringDecrypter(module, stringDecrypter);
newOne.booleanDecrypter = new BooleanDecrypter(module, booleanDecrypter);
newOne.assemblyResolver = new AssemblyResolver(module, assemblyResolver);
newOne.resourceResolver = new ResourceResolver(module, resourceResolver);
newOne.methodsDecrypter.reloaded();
return newOne;
}
public override void deobfuscateBegin() {
base.deobfuscateBegin();
stringDecrypter.init(peImage, fileData, DeobfuscatedFile);
booleanDecrypter.init(fileData, DeobfuscatedFile);
booleanValueInliner = new BooleanValueInliner();
emptyClass = new EmptyClass(module);
if (options.DecryptBools) {
booleanValueInliner.add(booleanDecrypter.Method, (method, args) => {
return booleanDecrypter.decrypt((int)args[0]);
});
}
foreach (var info in stringDecrypter.DecrypterInfos) {
staticStringDecrypter.add(info.method, (method2, args) => {
return stringDecrypter.decrypt(method2, (int)args[0]);
});
}
if (stringDecrypter.OtherStringDecrypter != null) {
staticStringDecrypter.add(stringDecrypter.OtherStringDecrypter, (method2, args) => {
return stringDecrypter.decrypt((string)args[0]);
});
}
DeobfuscatedFile.stringDecryptersAdded();
metadataTokenObfuscator = new MetadataTokenObfuscator(module);
antiStrongname = new AntiStrongName(getDecrypterType());
bool removeResourceResolver = false;
if (options.DecryptResources) {
resourceResolver.init(DeobfuscatedFile, this);
decryptResources();
if (options.InlineMethods) {
addTypeToBeRemoved(resourceResolver.Type, "Resource decrypter type");
removeResourceResolver = true;
}
addEntryPointCallToBeRemoved(resourceResolver.InitMethod);
addCctorInitCallToBeRemoved(resourceResolver.InitMethod);
}
if (resourceResolver.Detected && !removeResourceResolver && !resourceResolver.FoundResource)
canRemoveDecrypterType = false; // There may be calls to its .ctor
if (Operations.DecryptStrings != OpDecryptString.None)
addResourceToBeRemoved(stringDecrypter.Resource, "Encrypted strings");
else
canRemoveDecrypterType = false;
if (options.DecryptMethods && !methodsDecrypter.HasNativeMethods) {
addResourceToBeRemoved(methodsDecrypter.Resource, "Encrypted methods");
addCctorInitCallToBeRemoved(methodsDecrypter.Method);
}
else
canRemoveDecrypterType = false;
if (options.DecryptBools)
addResourceToBeRemoved(booleanDecrypter.Resource, "Encrypted booleans");
else
canRemoveDecrypterType = false;
if (!options.RemoveAntiStrongName)
canRemoveDecrypterType = false;
// The inlined methods may contain calls to the decrypter class
if (!options.InlineMethods)
canRemoveDecrypterType = false;
if (options.DumpEmbeddedAssemblies) {
if (options.InlineMethods)
addTypeToBeRemoved(assemblyResolver.Type, "Assembly resolver");
addEntryPointCallToBeRemoved(assemblyResolver.InitMethod);
addCctorInitCallToBeRemoved(assemblyResolver.InitMethod);
dumpEmbeddedAssemblies();
}
if (options.InlineMethods)
addTypeToBeRemoved(metadataTokenObfuscator.Type, "Metadata token obfuscator");
addCctorInitCallToBeRemoved(emptyClass.Method);
addCtorInitCallToBeRemoved(emptyClass.Method);
addEntryPointCallToBeRemoved(emptyClass.Method);
if (options.InlineMethods)
addTypeToBeRemoved(emptyClass.Type, "Empty class");
startedDeobfuscating = true;
}
void addEntryPointCallToBeRemoved(MethodDefinition methodToBeRemoved) {
var entryPoint = module.EntryPoint;
addCallToBeRemoved(entryPoint, methodToBeRemoved);
foreach (var info in DotNetUtils.getCalledMethods(module, entryPoint))
addCallToBeRemoved(info.Item2, methodToBeRemoved);
}
void decryptResources() {
var rsrc = resourceResolver.mergeResources();
if (rsrc == null)
return;
addResourceToBeRemoved(rsrc, "Encrypted resources");
}
void dumpEmbeddedAssemblies() {
if (!options.DumpEmbeddedAssemblies)
return;
foreach (var info in assemblyResolver.getEmbeddedAssemblies(DeobfuscatedFile, this)) {
var simpleName = Utils.getAssemblySimpleName(info.name);
DeobfuscatedFile.createAssemblyFile(info.resource.GetResourceData(), simpleName);
addResourceToBeRemoved(info.resource, string.Format("Embedded assembly: {0}", info.name));
}
}
public override bool deobfuscateOther(Blocks blocks) {
if (booleanValueInliner.HasHandlers)
return booleanValueInliner.decrypt(blocks) > 0;
return false;
}
public override void deobfuscateMethodEnd(Blocks blocks) {
metadataTokenObfuscator.deobfuscate(blocks);
fixTypeofDecrypterInstructions(blocks);
removeAntiStrongNameCode(blocks);
base.deobfuscateMethodEnd(blocks);
}
void removeAntiStrongNameCode(Blocks blocks) {
if (!options.RemoveAntiStrongName)
return;
if (antiStrongname.remove(blocks))
Log.v("Removed anti strong name code");
}
TypeDefinition getDecrypterType() {
return methodsDecrypter.DecrypterType ?? stringDecrypter.DecrypterType ?? booleanDecrypter.DecrypterType;
}
void fixTypeofDecrypterInstructions(Blocks blocks) {
var type = getDecrypterType();
if (type == null)
return;
foreach (var block in blocks.MethodBlocks.getAllBlocks()) {
var instructions = block.Instructions;
for (int i = 0; i < instructions.Count; i++) {
var instr = instructions[i];
if (instr.OpCode.Code != Code.Ldtoken)
continue;
if (!MemberReferenceHelper.compareTypes(type, instr.Operand as TypeReference))
continue;
instructions[i] = new Instr(Instruction.Create(OpCodes.Ldtoken, blocks.Method.DeclaringType));
}
}
}
public override void deobfuscateEnd() {
removeInlinedMethods();
if (options.RestoreTypes)
new TypesRestorer(module).deobfuscate();
var decrypterType = getDecrypterType();
if (canRemoveDecrypterType && isTypeCalled(decrypterType))
canRemoveDecrypterType = false;
if (canRemoveDecrypterType)
addTypeToBeRemoved(decrypterType, "Decrypter type");
else
Log.v("Could not remove decrypter type");
base.deobfuscateEnd();
}
void removeInlinedMethods() {
if (!options.InlineMethods || !options.RemoveInlinedMethods)
return;
findAndRemoveInlinedMethods();
}
public override IEnumerable<string> getStringDecrypterMethods() {
var list = new List<string>();
foreach (var info in stringDecrypter.DecrypterInfos)
list.Add(info.method.MetadataToken.ToInt32().ToString("X8"));
if (stringDecrypter.OtherStringDecrypter != null)
list.Add(stringDecrypter.OtherStringDecrypter.MetadataToken.ToInt32().ToString("X8"));
return list;
}
public override void OnBeforeAddingResources(MetadataBuilder builder) {
if (!options.DecryptMethods)
return;
methodsDecrypter.encryptNativeMethods(builder);
}
}
}