修复 AddXor的bug

backup
walon 2025-04-22 22:53:51 +08:00
parent 3fded4273c
commit 6d786330d1
6 changed files with 155 additions and 43 deletions

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@ -1,4 +1,5 @@
using dnlib.DotNet;
using dnlib.DotNet.Emit;
using Obfuz.Utils;
using System;
using System.Collections.Generic;
@ -23,13 +24,15 @@ namespace Obfuz.Emit
}
}
public class RvaDataAllocator
public class ModuleRvaDataAllocator
{
// randomized
const int maxRvaDataSize = 0x100;
private readonly ModuleDef _module;
private readonly IRandom _random;
class RvaField
{
public FieldDef holderDataField;
@ -53,49 +56,50 @@ namespace Obfuz.Emit
private TypeDef _rvaTypeDef;
private readonly Dictionary<(ModuleDef, int), TypeDef> _dataHolderTypeBySizes = new Dictionary<(ModuleDef, int), TypeDef>();
private readonly Dictionary<int, TypeDef> _dataHolderTypeBySizes = new Dictionary<int, TypeDef>();
public RvaDataAllocator(IRandom random)
public ModuleRvaDataAllocator(ModuleDef mod, IRandom random)
{
_module = mod;
_random = random;
}
private (FieldDef, FieldDef) CreateDataHolderRvaField(ModuleDef mod, TypeDef dataHolderType)
private (FieldDef, FieldDef) CreateDataHolderRvaField(TypeDef dataHolderType)
{
if (_rvaTypeDef == null)
{
mod.EnableTypeDefFindCache = false;
//_rvaTypeDef = mod.Find("$ObfuzRVA$", false);
_module.EnableTypeDefFindCache = false;
//_rvaTypeDef = _module.Find("$ObfuzRVA$", false);
//if (_rvaTypeDef != null)
//{
// throw new Exception($"can't obfuscate a obfuscated assembly");
//}
ITypeDefOrRef objectTypeRef = mod.Import(typeof(object));
_rvaTypeDef = new TypeDefUser("$Obfuz$RVA$",objectTypeRef);
mod.Types.Add(_rvaTypeDef);
mod.EnableTypeDefFindCache = true;
ITypeDefOrRef objectTypeRef = _module.Import(typeof(object));
_rvaTypeDef = new TypeDefUser("$Obfuz$RVA$", objectTypeRef);
_module.Types.Add(_rvaTypeDef);
_module.EnableTypeDefFindCache = true;
}
var holderField = new FieldDefUser($"$RVA_Data{_rvaTypeDef.Fields.Count}", new FieldSig(dataHolderType.ToTypeSig()), FieldAttributes.InitOnly | FieldAttributes.Static | FieldAttributes.HasFieldRVA);
var holderField = new FieldDefUser($"$RVA_Data{_rvaTypeDef.Fields.Count}", new FieldSig(dataHolderType.ToTypeSig()), FieldAttributes.InitOnly | FieldAttributes.Static | FieldAttributes.HasFieldRVA);
holderField.DeclaringType = _rvaTypeDef;
var runtimeValueField = new FieldDefUser($"$RVA_Value{_rvaTypeDef.Fields.Count}", new FieldSig(new SZArraySig(mod.CorLibTypes.Byte)), FieldAttributes.Static);
var runtimeValueField = new FieldDefUser($"$RVA_Value{_rvaTypeDef.Fields.Count}", new FieldSig(new SZArraySig(_module.CorLibTypes.Byte)), FieldAttributes.Static);
runtimeValueField.DeclaringType = _rvaTypeDef;
return (holderField, runtimeValueField);
}
private TypeDef GetDataHolderType(ModuleDef mod, int size)
private TypeDef GetDataHolderType(int size)
{
size = (size + 15) & ~15; // align to 6 bytes
if (_dataHolderTypeBySizes.TryGetValue((mod, size), out var type))
if (_dataHolderTypeBySizes.TryGetValue(size, out var type))
return type;
var dataHolderType = new TypeDefUser($"$ObfuzRVA$DataHolder{size}", mod.Import(typeof(ValueType)));
var dataHolderType = new TypeDefUser($"$ObfuzRVA$DataHolder{size}", _module.Import(typeof(ValueType)));
dataHolderType.Layout = TypeAttributes.ExplicitLayout;
dataHolderType.PackingSize = 1;
dataHolderType.ClassSize = (uint)size;
_dataHolderTypeBySizes.Add((mod, size), dataHolderType);
mod.Types.Add(dataHolderType);
_dataHolderTypeBySizes.Add(size, dataHolderType);
_module.Types.Add(dataHolderType);
return dataHolderType;
}
@ -104,10 +108,10 @@ namespace Obfuz.Emit
return (size + alignment - 1) & ~(alignment - 1);
}
private RvaField CreateRvaField(ModuleDef mod, int size)
private RvaField CreateRvaField(int size)
{
TypeDef dataHolderType = GetDataHolderType(mod, size);
var (holderDataField, runtimeValueField) = CreateDataHolderRvaField(mod, dataHolderType);
TypeDef dataHolderType = GetDataHolderType(size);
var (holderDataField, runtimeValueField) = CreateDataHolderRvaField(dataHolderType);
var newRvaField = new RvaField
{
holderDataField = holderDataField,
@ -119,13 +123,13 @@ namespace Obfuz.Emit
return newRvaField;
}
private RvaField GetRvaField(ModuleDef mod, int preservedSize, int alignment)
private RvaField GetRvaField(int preservedSize, int alignment)
{
Assert.IsTrue(preservedSize % alignment == 0);
// for big size, create a new field
if (preservedSize >= maxRvaDataSize)
{
return CreateRvaField(mod, preservedSize);
return CreateRvaField(preservedSize);
}
if (_currentField != null)
@ -147,61 +151,101 @@ namespace Obfuz.Emit
_currentField.FillPadding();
}
_currentField = CreateRvaField(mod, maxRvaDataSize);
_currentField = CreateRvaField(maxRvaDataSize);
return _currentField;
}
public RvaData Allocate(ModuleDef mod, int value)
public RvaData Allocate(int value)
{
RvaField field = GetRvaField(mod, 4, 4);
RvaField field = GetRvaField(4, 4);
int offset = field.bytes.Count;
Assert.IsTrue(offset % 4 == 0);
field.bytes.AddRange(BitConverter.GetBytes(value));
return new RvaData(field.runtimeValueField, offset, 4);
}
public RvaData Allocate(ModuleDef mod, long value)
public RvaData Allocate(long value)
{
RvaField field = GetRvaField(mod, 8, 8);
RvaField field = GetRvaField(8, 8);
int offset = field.bytes.Count;
Assert.IsTrue(offset % 8 == 0);
field.bytes.AddRange(BitConverter.GetBytes(value));
return new RvaData(field.runtimeValueField, offset, 8);
}
public RvaData Allocate(ModuleDef mod, float value)
public RvaData Allocate(float value)
{
RvaField field = GetRvaField(mod, 4, 4);
RvaField field = GetRvaField(4, 4);
int offset = field.bytes.Count;
Assert.IsTrue(offset % 4 == 0);
field.bytes.AddRange(BitConverter.GetBytes(value));
return new RvaData(field.runtimeValueField, offset, 4);
}
public RvaData Allocate(ModuleDef mod, double value)
public RvaData Allocate(double value)
{
RvaField field = GetRvaField(mod, 8, 8);
RvaField field = GetRvaField(8, 8);
int offset = field.bytes.Count;
Assert.IsTrue(offset % 8 == 0);
field.bytes.AddRange(BitConverter.GetBytes(value));
return new RvaData(field.runtimeValueField, offset, 8);
}
public RvaData Allocate(ModuleDef mod, string value)
public RvaData Allocate(string value)
{
byte[] bytes = Encoding.UTF8.GetBytes(value);
return Allocate(mod, bytes);
return Allocate(bytes);
}
public RvaData Allocate(ModuleDef mod, byte[] value)
public RvaData Allocate(byte[] value)
{
RvaField field = GetRvaField(mod, value.Length, 1);
RvaField field = GetRvaField(value.Length, 1);
int offset = field.bytes.Count;
field.bytes.AddRange(value);
return new RvaData(field.runtimeValueField, offset, value.Length);
}
public void SetFieldsRVA()
private void CreateCCtorOfRvaTypeDef()
{
if (_rvaTypeDef == null)
{
return;
}
ModuleDef mod = _rvaTypeDef.Module;
var cctor = new MethodDefUser(".cctor",
MethodSig.CreateStatic(_module.CorLibTypes.Void),
MethodImplAttributes.IL | MethodImplAttributes.Managed,
MethodAttributes.Static | MethodAttributes.HideBySig | MethodAttributes.SpecialName | MethodAttributes.RTSpecialName | MethodAttributes.Private);
cctor.DeclaringType = _rvaTypeDef;
//_rvaTypeDef.Methods.Add(cctor);
var body = new CilBody();
cctor.Body = body;
var ins = body.Instructions;
IMethod method = mod.Import(typeof(System.Runtime.CompilerServices.RuntimeHelpers).GetMethod("InitializeArray", new[] { typeof(Array), typeof(RuntimeFieldHandle) }));
Assert.IsNotNull(method);
foreach (var field in _rvaFields)
{
// ldc
// newarr
// dup
// stsfld
// ldtoken
// RuntimeHelpers.InitializeArray(array, fieldHandle);
ins.Add(Instruction.Create(OpCodes.Ldc_I4, (int)field.size));
ins.Add(Instruction.Create(OpCodes.Newarr, field.runtimeValueField.FieldType.Next.ToTypeDefOrRef()));
ins.Add(Instruction.Create(OpCodes.Dup));
ins.Add(Instruction.Create(OpCodes.Stsfld, field.runtimeValueField));
ins.Add(Instruction.Create(OpCodes.Ldtoken, field.holderDataField));
ins.Add(Instruction.Create(OpCodes.Call, method));
// TODO Decrpyt
}
ins.Add(Instruction.Create(OpCodes.Ret));
}
private void SetFieldsRVA()
{
foreach (var field in _rvaFields)
{
@ -213,5 +257,71 @@ namespace Obfuz.Emit
field.holderDataField.InitialValue = field.bytes.ToArray();
}
}
public void Done()
{
SetFieldsRVA();
CreateCCtorOfRvaTypeDef();
}
}
public class RvaDataAllocator
{
private readonly IRandom _random;
private readonly Dictionary<ModuleDef, ModuleRvaDataAllocator> _modules = new Dictionary<ModuleDef, ModuleRvaDataAllocator>();
public RvaDataAllocator(IRandom random)
{
_random = random;
}
private ModuleRvaDataAllocator GetModuleRvaDataAllocator(ModuleDef mod)
{
if (!_modules.TryGetValue(mod, out var allocator))
{
allocator = new ModuleRvaDataAllocator(mod, _random);
_modules.Add(mod, allocator);
}
return allocator;
}
public RvaData Allocate(ModuleDef mod, int value)
{
return GetModuleRvaDataAllocator(mod).Allocate(value);
}
public RvaData Allocate(ModuleDef mod, long value)
{
return GetModuleRvaDataAllocator(mod).Allocate(value);
}
public RvaData Allocate(ModuleDef mod, float value)
{
return GetModuleRvaDataAllocator(mod).Allocate(value);
}
public RvaData Allocate(ModuleDef mod, double value)
{
return GetModuleRvaDataAllocator(mod).Allocate(value);
}
public RvaData Allocate(ModuleDef mod, string value)
{
return GetModuleRvaDataAllocator(mod).Allocate(value);
}
public RvaData Allocate(ModuleDef mod, byte[] value)
{
return GetModuleRvaDataAllocator(mod).Allocate(value);
}
public void Done()
{
foreach (var allocator in _modules.Values)
{
allocator.Done();
}
}
}
}

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@ -1,4 +1,5 @@
using System;
using System.Runtime.CompilerServices;
namespace Obfuz.Virtualization
{
@ -41,8 +42,8 @@ namespace Obfuz.Virtualization
}
case DataNodeType.Bytes:
{
// create ldstr
// ldsfld
// ldtoken
// RuntimeHelpers.InitializeArray(array, fieldHandle);
break;
}

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@ -116,7 +116,7 @@ namespace Obfuz.Virtualization
ctx.output.Add(Instruction.Create(OpCodes.Ldsfld, rvaData.field));
output.Add(Instruction.Create(OpCodes.Ldc_I4, rvaData.offset));
output.Add(Instruction.Create(OpCodes.Ldc_I4, rvaData.size));
output.Add(Instruction.Create(OpCodes.Newarr, new SZArraySig(mod.CorLibTypes.Byte).ToTypeDefOrRef()));
output.Add(Instruction.Create(OpCodes.Newarr, mod.CorLibTypes.Byte.ToTypeDefOrRef()));
output.Add(Instruction.Create(OpCodes.Ldc_I4, 0));
output.Add(Instruction.Create(OpCodes.Ldc_I4, rvaData.size));
output.Add(Instruction.Create(OpCodes.Call, convertMethod));

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@ -74,7 +74,7 @@ namespace Obfuz.Virtualization
public void Stop()
{
_rvaDataAllocator.SetFieldsRVA();
_rvaDataAllocator.Done();
}
}
}

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@ -24,7 +24,7 @@ namespace Obfuz.Virtualization.Functions
public override void CompileSelf(CompileContext ctx, List<Instruction> output)
{
output.Add(Instruction.Create(OpCodes.And));
output.Add(Instruction.Create(OpCodes.Xor));
}
}
}

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@ -30,10 +30,11 @@ namespace Obfuz.Virtualization
{
throw new System.Exception($"No functions available for type {type}");
}
if (options.depth >= 4)
if (options.depth >= 2)
{
//return new ConstDataNode() { Type = type, Value = value };
return _random.NextInt(100) < 50 ?
//return _random.NextInt(100) < 50 ?
return true ?
new ConstFromFieldRvaDataNode() { Type = type, Value = value } :
new ConstDataNode() { Type = type, Value = value };
}