initial commit

Obfuscator.Obfuscator.Mutation2/Func.cs

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+using System;
+using System.Linq;
+using dnlib.DotNet;
+using dnlib.DotNet.Emit;
+
+namespace Obfuscator.Obfuscator.Mutation2;
+
+public class Func : iMutation
+{
+	public FieldDef Decryptor { get; set; }
+
+	public void Process(MethodDef method, ref int index)
+	{
+		int ldcI4Value = method.Body.Instructions[index].GetLdcI4Value();
+		method.Body.Instructions[index].OpCode = OpCodes.Ldsfld;
+		method.Body.Instructions[index].Operand = Decryptor;
+		method.Body.Instructions.Insert(++index, new Instruction(OpCodes.Ldc_I4, ldcI4Value));
+		method.Body.Instructions.Insert(++index, new Instruction(OpCodes.Callvirt, method.Module.Import(typeof(Func<int, int>).GetMethod("Invoke"))));
+		index -= 2;
+	}
+
+	public FieldDef CreateProperField(TypeDef type)
+	{
+		TypeDef typeDef = ModuleDefMD.Load(typeof(FuncMutation).Module).ResolveTypeDef(MDToken.ToRID(typeof(FuncMutation).MetadataToken));
+		FieldDef fieldDef = typeDef.Fields.FirstOrDefault((FieldDef x) => x.Name == "prao");
+		fieldDef.DeclaringType = null;
+		type.Fields.Add(fieldDef);
+		MethodDef methodDef = typeDef.FindMethod("RET");
+		methodDef.DeclaringType = null;
+		type.Methods.Add(methodDef);
+		MethodDef methodDef2 = type.FindOrCreateStaticConstructor();
+		methodDef2.Body.Instructions.Insert(0, new Instruction(OpCodes.Ldnull));
+		methodDef2.Body.Instructions.Insert(1, new Instruction(OpCodes.Ldftn, methodDef));
+		methodDef2.Body.Instructions.Insert(2, new Instruction(OpCodes.Newobj, type.Module.Import(typeof(Func<int, int>).GetConstructors().First())));
+		methodDef2.Body.Instructions.Insert(3, new Instruction(OpCodes.Stsfld, fieldDef));
+		methodDef2.Body.Instructions.Insert(4, new Instruction(OpCodes.Nop));
+		return fieldDef;
+	}
+
+	public void Prepare(TypeDef type)
+	{
+		Decryptor = CreateProperField(type);
+	}
+
+	public bool Supported(Instruction instr)
+	{
+		return Utils.CheckArithmetic(instr);
+	}
+}