添加int相关混淆算法

Editor/Utils/IRandom.cs

@@ -1,9 +1,11 @@
-namespace Obfuz.Virtualization
+namespace Obfuz.Utils
 {
     public interface IRandom
     {
         int NextInt(int min, int max);
 
         int NextInt(int max);
+
+        int NextInt();
     }
 }

Editor/Utils/RandomWithKey.cs

@@ -0,0 +1,58 @@
+using Obfuz.Virtualization;
+using System;
+using System.Collections.Generic;
+using System.Linq;
+using System.Text;
+using System.Threading.Tasks;
+
+namespace Obfuz.Utils
+{
+    public class RandomWithKey : IRandom
+    {
+        private readonly byte[] _key;
+
+        private readonly Random _random;
+
+        private int _nextIndex;
+
+        public RandomWithKey(byte[] key, int seed)
+        {
+            _key = key;
+            // TODO use key and seed to generate a random number
+            _random = new Random(GenerateSeed(key, seed));
+        }
+
+        private int GenerateSeed(byte[] key, int seed)
+        {
+            foreach (var b in key)
+            {
+                seed = seed * 31 + b;
+            }
+            return seed;
+        }
+
+        public int NextInt(int min, int max)
+        {
+            return min + NextInt(max - min);
+        }
+
+        public int NextInt(int max)
+        {
+            return (int)((uint)NextInt() % (uint)max);
+        }
+
+        private int GetNextKeyByte()
+        {
+            if (_nextIndex >= _key.Length)
+            {
+                _nextIndex = 0;
+            }
+            return _key[_nextIndex++];
+        }
+
+        public int NextInt()
+        {
+            return _random.Next() ^ GetNextKeyByte();
+        }
+    }
+}

Editor/Virtualization/ConfigDataObfuscationPolicy.cs

@@ -1,4 +1,5 @@
-using System;
+using dnlib.DotNet;
+using System;
 using System.Collections.Generic;
 using System.Linq;
 using System.Text;
@@ -8,5 +9,34 @@ namespace Obfuz.Virtualization
 {
     public class ConfigDataObfuscationPolicy : DataObfuscationPolicyBase
     {
+        public override bool NeedObfuscateMethod(MethodDef method)
+        {
+            return true;
+        }
+
+        public override bool NeedObfuscateInt(MethodDef method, int value)
+        {
+            return value > 10000;
+        }
+
+        public override bool NeedObfuscateLong(MethodDef method, long value)
+        {
+            return value > 10000;
+        }
+
+        public override bool NeedObfuscateFloat(MethodDef method, float value)
+        {
+            return true;
+        }
+
+        public override bool NeedObfuscateDouble(MethodDef method, double value)
+        {
+            return true;
+        }
+
+        public override bool NeedObfuscateString(MethodDef method, string value)
+        {
+            return true;
+        }
     }
 }

Editor/Virtualization/CreateExpressionOptions.cs

@@ -1,4 +1,6 @@
-namespace Obfuz.Virtualization
+using Obfuz.Utils;
+
+namespace Obfuz.Virtualization
 {
     public struct CreateExpressionOptions
     {

Editor/Virtualization/DataNodeCreatorBase.cs

@@ -0,0 +1,7 @@
+namespace Obfuz.Virtualization
+{
+    public abstract class DataNodeCreatorBase : IDataNodeCreator
+    {
+        public abstract IDataNode CreateRandom(DataNodeType type, object value, CreateExpressionOptions options);
+    }
+}

Editor/Virtualization/DataNodes/DataNodeBase.cs

@@ -2,11 +2,9 @@
 {
     public abstract class DataNodeBase : IDataNode
     {
-        public DataNodeType Type { get; protected set; }
+        public DataNodeType Type { get; set; }
 
-        public IDataNode Expr { get; protected set; }
-
-        public abstract object Value { get; protected set; }
+        public abstract object Value { get; set; }
 
         public abstract void Compile(CompileContext ctx);
     }
@@ -14,12 +12,12 @@
 
     public abstract class DataNodeBase<T> : DataNodeBase
     {
-        public T Value2 { get; protected set; }
+        public T Value2 { get; set; }
 
         public override object Value
         {
             get => Value2;
-            protected set => Value2 = (T)value;
+            set => Value2 = (T)value;
         }
     }
 
@@ -31,7 +29,7 @@
         public override object Value
         {
             get => _value;
-            protected set => _value = value;
+            set => _value = value;
         }
     }
 }

Editor/Virtualization/DataVirtualizationPass.cs

@@ -34,7 +34,7 @@ namespace Obfuz.Virtualization
                 {
                     foreach (MethodDef method in type.Methods)
                     {
-                        if (!method.HasBody && !_dataObfuscatorPolicy.NeedObfuscateMethod(method))
+                        if (!method.HasBody || !_dataObfuscatorPolicy.NeedObfuscateMethod(method))
                         {
                             continue;
                         }
@@ -50,7 +50,7 @@ namespace Obfuz.Virtualization
             IList<Instruction> instructions = method.Body.Instructions;
             var obfuscatedInstructions = new List<Instruction>();
             var resultInstructions = new List<Instruction>();
-            for (int i = 0; i < instructions.Count; )
+            for (int i = 0; i < instructions.Count; i++)
             {
                 Instruction inst = instructions[i];
                 bool obfuscated = false;
@@ -130,10 +130,8 @@ namespace Obfuz.Virtualization
                         }
                         break;
                     }
-                    default: throw new NotSupportedException($"Unsupported operand type: {inst.OpCode.OperandType} for instruction: {inst}");
                 }
                 resultInstructions.Add(inst);
-                i++;
                 if (obfuscated)
                 {
                     // current instruction may be the target of control flow instruction, so we can't remove it directly.
@@ -141,9 +139,14 @@ namespace Obfuz.Virtualization
                     inst.OpCode = OpCodes.Nop;
                     inst.Operand = null;
                     resultInstructions.AddRange(obfuscatedInstructions);
-                    i += obfuscatedInstructions.Count + 1;
                 }
             }
+
+            instructions.Clear();
+            foreach (var obInst in obfuscatedInstructions)
+            {
+                instructions.Add(obInst);
+            }
         }
     }
 }

Editor/Virtualization/DefaultDataObfuscator.cs

@@ -7,34 +7,38 @@ namespace Obfuz.Virtualization
 {
     public class DefaultDataObfuscator : IDataObfuscator
     {
-        public bool ObfuscateInt(MethodDef method, int value, List<Instruction> obfuscatedInstructions)
+        private readonly RandomDataNodeCreator _nodeCreator = new RandomDataNodeCreator();
+
+        public void ObfuscateInt(MethodDef method, int value, List<Instruction> obfuscatedInstructions)
         {
-            return false;
+            IDataNode node = _nodeCreator.CreateRandom(DataNodeType.Int32, value);
+            obfuscatedInstructions.Add(Instruction.CreateLdcI4(value));
         }
 
-        public bool TryObfuscateLong(MethodDef method, long value, List<Instruction> obfuscatedInstructions)
+        public void ObfuscateLong(MethodDef method, long value, List<Instruction> obfuscatedInstructions)
         {
-            return false;
+            obfuscatedInstructions.Add(Instruction.Create(OpCodes.Ldc_I8, value));
         }
 
-        public bool TryObfuscateFloat(MethodDef method, float value, List<Instruction> obfuscatedInstructions)
+        public void ObfuscateFloat(MethodDef method, float value, List<Instruction> obfuscatedInstructions)
         {
-            return false;
+            obfuscatedInstructions.Add(Instruction.Create(OpCodes.Ldc_R4, value));
         }
 
-        public bool TryObfuscateDouble(MethodDef method, double value, List<Instruction> obfuscatedInstructions)
+        public void ObfuscateDouble(MethodDef method, double value, List<Instruction> obfuscatedInstructions)
         {
-            return false;
+            obfuscatedInstructions.Add(Instruction.Create(OpCodes.Ldc_R8, value));
         }
 
-        public bool TryObfuscateBytes(MethodDef method, Array value, List<Instruction> obfuscatedInstructions)
+        public void ObfuscateBytes(MethodDef method, Array value, List<Instruction> obfuscatedInstructions)
         {
-            return false;
+            throw new NotSupportedException();
+            //obfuscatedInstructions.Add(Instruction.Create(OpCodes.Ldc_I4, value.Length));
         }
 
-        public bool TryObfuscateString(MethodDef method, string value, List<Instruction> obfuscatedInstructions)
+        public void ObfuscateString(MethodDef method, string value, List<Instruction> obfuscatedInstructions)
         {
-            return false;
+            obfuscatedInstructions.Add(Instruction.Create(OpCodes.Ldstr, value));
         }
     }
 }

Editor/Virtualization/Functions/FunctionBase.cs

@@ -11,10 +11,10 @@ namespace Obfuz.Virtualization
 
         public abstract void CreateArguments(DataNodeType type, object value, CreateExpressionOptions options, List<ConstValue> args);
 
-        public ConstExpression CreateCallable(IDataNode result, CreateExpressionOptions options)
+        public ConstExpression CreateCallable(DataNodeType type, object value, CreateExpressionOptions options)
         {
             var args = new List<ConstValue>();
-            CreateArguments(result.Type, result.Value, options, args);
+            CreateArguments(type, value, options, args);
 
             options.depth += 1;
             var argNodes = new List<IDataNode>();
@@ -24,7 +24,7 @@ namespace Obfuz.Virtualization
                 argNodes.Add(argNode);
             }
             
-            return new ConstExpression(this, args.Select(a => options.expressionCreator.CreateRandom(a.type, a.value, options)).ToList(), new ConstValue(result.Type, result.Value));
+            return new ConstExpression(this, args.Select(a => options.expressionCreator.CreateRandom(a.type, a.value, options)).ToList(), new ConstValue(type, value));
         }
     }
 }

Editor/Virtualization/Functions/Int32FunctionAdd.cs

@@ -16,7 +16,7 @@ namespace Obfuz.Virtualization.Functions
         {
             int value = (int)v;
 
-            int op1 = value >= 0 ? options.random.NextInt(value) : -options.random.NextInt(-value);
+            int op1 = options.random.NextInt();
             int op2 = value - op1;
             args.Add(new ConstValue(DataNodeType.Int32, op1));
             args.Add(new ConstValue(DataNodeType.Int32, op2));

Editor/Virtualization/Functions/Int32FunctionXor.cs

@@ -0,0 +1,25 @@
+using System;
+using System.Collections.Generic;
+using System.Data;
+using System.Linq;
+using System.Text;
+using System.Threading.Tasks;
+using static UnityEngine.Networking.UnityWebRequest;
+
+namespace Obfuz.Virtualization.Functions
+{
+    public class Int32FunctionXor : Int32FunctionBase
+    {
+        public override DataNodeType ReturnType => DataNodeType.Int32;
+
+        public override void CreateArguments(DataNodeType type, object v, CreateExpressionOptions options, List<ConstValue> args)
+        {
+            int value = (int)v;
+
+            int op1 = options.random.NextInt();
+            int op2 = value ^ op1;
+            args.Add(new ConstValue(DataNodeType.Int32, op1));
+            args.Add(new ConstValue(DataNodeType.Int32, op2));
+        }
+    }
+}

Editor/Virtualization/IDataNode.cs

@@ -13,8 +13,6 @@ namespace Obfuz.Virtualization
 
         object Value { get; }
 
-        IDataNode Expr { get; }
-
         void Compile(CompileContext ctx);
     }
 }

Editor/Virtualization/IFunction.cs

@@ -4,6 +4,6 @@
     {
         DataNodeType ReturnType { get; }
 
-        ConstExpression CreateCallable(IDataNode result, CreateExpressionOptions options);
+        ConstExpression CreateCallable(DataNodeType type, object value, CreateExpressionOptions options);
     }
 }

Editor/Virtualization/RandomDataNodeCreator.cs

@@ -0,0 +1,50 @@
+
+using Obfuz.Utils;
+using Obfuz.Virtualization.Functions;
+using System.Collections.Generic;
+
+namespace Obfuz.Virtualization
+{
+    public class RandomDataNodeCreator : DataNodeCreatorBase
+    {
+        private readonly Dictionary<DataNodeType, List<IFunction>> _functions = new Dictionary<DataNodeType, List<IFunction>>();
+
+        private readonly IRandom _random = new RandomWithKey(new byte[] { 0x1, 0x2, 0x3, 0x4 }, 0x5);
+
+        public RandomDataNodeCreator()
+        {
+            var int32Funcs = new List<IFunction>()
+            {
+                new Int32FunctionAdd(),
+                new Int32FunctionXor(),
+            };
+            _functions.Add(DataNodeType.Int32, int32Funcs);
+        }
+
+        public override IDataNode CreateRandom(DataNodeType type, object value, CreateExpressionOptions options)
+        {
+            if (!_functions.TryGetValue(type, out var funcs))
+            {
+                throw new System.Exception($"No functions available for type {type}");
+            }
+            if (options.depth >= 2)
+            {
+                return new ConstDataNode() { Type = type, Value = value };
+            }
+            var func = funcs[options.random.NextInt(funcs.Count)];
+            ++options.depth;
+            return func.CreateCallable(type, value, options);
+        }
+
+        public IDataNode CreateRandom(DataNodeType type, object value)
+        {
+            var options = new CreateExpressionOptions
+            {
+                depth = 0,
+                random = _random,
+                expressionCreator = this,
+            };
+            return CreateRandom(type, value, options);
+        }
+    }
+}