153 lines
4.2 KiB
C#
153 lines
4.2 KiB
C#
/*
|
|
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 <http://www.gnu.org/licenses/>.
|
|
*/
|
|
|
|
using System.Collections.Generic;
|
|
using dnlib.DotNet;
|
|
using dnlib.DotNet.Emit;
|
|
using de4dot.blocks;
|
|
|
|
namespace de4dot.code.deobfuscators.CodeVeil {
|
|
class TamperDetection {
|
|
ModuleDefMD module;
|
|
MainType mainType;
|
|
TypeDef tamperDetectionType;
|
|
List<MethodDef> tamperDetectionMethods = new List<MethodDef>();
|
|
|
|
public TypeDef Type {
|
|
get { return tamperDetectionType; }
|
|
}
|
|
|
|
public List<MethodDef> Methods {
|
|
get { return tamperDetectionMethods; }
|
|
}
|
|
|
|
public TamperDetection(ModuleDefMD module, MainType mainType) {
|
|
this.module = module;
|
|
this.mainType = mainType;
|
|
}
|
|
|
|
public void initialize() {
|
|
if (!mainType.Detected)
|
|
return;
|
|
|
|
if (mainType.TamperCheckMethod == null)
|
|
return;
|
|
|
|
findTamperDetectionTypes();
|
|
}
|
|
|
|
void findTamperDetectionTypes() {
|
|
foreach (var type in module.Types) {
|
|
if (!type.HasNestedTypes)
|
|
continue;
|
|
if ((type.Attributes & ~TypeAttributes.Sealed) != 0)
|
|
continue;
|
|
|
|
if (!checkTamperDetectionClasses(type.NestedTypes))
|
|
continue;
|
|
|
|
tamperDetectionType = type;
|
|
findTamperDetectionMethods();
|
|
return;
|
|
}
|
|
}
|
|
|
|
void findTamperDetectionMethods() {
|
|
foreach (var type in tamperDetectionType.NestedTypes) {
|
|
foreach (var method in type.Methods) {
|
|
if (!method.IsStatic || method.Body == null)
|
|
continue;
|
|
if (method.Name == ".cctor")
|
|
continue;
|
|
if (DotNetUtils.isMethod(method, "System.Void", "()"))
|
|
tamperDetectionMethods.Add(method);
|
|
}
|
|
}
|
|
}
|
|
|
|
bool checkTamperDetectionClasses(IEnumerable<TypeDef> types) {
|
|
foreach (var type in types) {
|
|
if (!isTamperDetectionClass(type))
|
|
return false;
|
|
}
|
|
return true;
|
|
}
|
|
|
|
bool isTamperDetectionClass(TypeDef type) {
|
|
if (type.BaseType == null || type.BaseType.FullName != "System.Object")
|
|
return false;
|
|
if ((type.Attributes & ~TypeAttributes.Sealed) != TypeAttributes.NestedAssembly)
|
|
return false;
|
|
|
|
MethodDef cctor = null, initMethod = null;
|
|
foreach (var method in type.Methods) {
|
|
if (InvalidMethodsFinder.isInvalidMethod(method))
|
|
continue;
|
|
if (!method.IsStatic || method.Body == null)
|
|
return false;
|
|
if (method.Name == ".cctor")
|
|
cctor = method;
|
|
else if (DotNetUtils.isMethod(method, "System.Void", "()"))
|
|
initMethod = method;
|
|
}
|
|
if (cctor == null || initMethod == null)
|
|
return false;
|
|
|
|
if (!callsMainTypeTamperCheckMethod(cctor))
|
|
return false;
|
|
|
|
return true;
|
|
}
|
|
|
|
bool callsMainTypeTamperCheckMethod(MethodDef method) {
|
|
foreach (var calledMethod in DotNetUtils.getCalledMethods(module, method)) {
|
|
if (calledMethod == mainType.TamperCheckMethod)
|
|
return true;
|
|
}
|
|
|
|
var instructions = method.Body.Instructions;
|
|
for (int i = 0; i < instructions.Count; i++) {
|
|
var instrs = DotNetUtils.getInstructions(instructions, i, OpCodes.Ldtoken, OpCodes.Call, OpCodes.Call, OpCodes.Ldc_I8, OpCodes.Call);
|
|
if (instrs == null)
|
|
continue;
|
|
|
|
if (!checkInvokeCall(instrs[1], "System.Type", "(System.RuntimeTypeHandle)"))
|
|
continue;
|
|
if (!checkInvokeCall(instrs[2], "System.Reflection.Assembly", "(System.Object)"))
|
|
continue;
|
|
if (!checkInvokeCall(instrs[4], "System.Void", "(System.Reflection.Assembly,System.UInt64)"))
|
|
continue;
|
|
|
|
return true;
|
|
}
|
|
|
|
return false;
|
|
}
|
|
|
|
static bool checkInvokeCall(Instruction instr, string returnType, string parameters) {
|
|
var method = instr.Operand as MethodDef;
|
|
if (method == null)
|
|
return false;
|
|
if (method.Name != "Invoke")
|
|
return false;
|
|
return DotNetUtils.isMethod(method, returnType, parameters);
|
|
}
|
|
}
|
|
}
|