/*
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 .
*/
using System;
using System.IO;
using Mono.Cecil;
using de4dot.blocks;
using de4dot.PE;
namespace de4dot.code.deobfuscators.CliSecure {
class CliSecureRtType {
ModuleDefinition module;
TypeDefinition cliSecureRtType;
MethodDefinition postInitializeMethod;
MethodDefinition initializeMethod;
MethodDefinition stringDecrypterMethod;
MethodDefinition loadMethod;
bool foundSig;
public bool Detected {
get { return foundSig || cliSecureRtType != null; }
}
public TypeDefinition Type {
get { return cliSecureRtType; }
}
public MethodDefinition StringDecrypterMethod {
get { return stringDecrypterMethod; }
}
public MethodDefinition PostInitializeMethod {
get { return postInitializeMethod; }
}
public MethodDefinition InitializeMethod {
get { return initializeMethod; }
}
public MethodDefinition LoadMethod {
get { return loadMethod; }
}
public CliSecureRtType(ModuleDefinition module) {
this.module = module;
}
public CliSecureRtType(ModuleDefinition module, CliSecureRtType oldOne) {
this.module = module;
cliSecureRtType = lookup(oldOne.cliSecureRtType, "Could not find CliSecureRt type");
postInitializeMethod = lookup(oldOne.postInitializeMethod, "Could not find postInitializeMethod method");
initializeMethod = lookup(oldOne.initializeMethod, "Could not find initializeMethod method");
stringDecrypterMethod = lookup(oldOne.stringDecrypterMethod, "Could not find stringDecrypterMethod method");
loadMethod = lookup(oldOne.loadMethod, "Could not find loadMethod method");
foundSig = oldOne.foundSig;
}
T lookup(T def, string errorMessage) where T : MemberReference {
return DeobUtils.lookup(module, def, errorMessage);
}
public void find() {
if (cliSecureRtType != null)
return;
if (find2())
return;
if (findOld())
return;
findNativeCode();
}
bool find2() {
foreach (var type in module.Types) {
if (type.Namespace != "")
continue;
var typeName = type.FullName;
MethodDefinition cs = null;
MethodDefinition initialize = null;
MethodDefinition postInitialize = null;
MethodDefinition load = null;
int methods = 0;
foreach (var method in type.Methods) {
if (method.FullName == "System.String " + typeName + "::cs(System.String)") {
cs = method;
methods++;
}
else if (method.FullName == "System.Void " + typeName + "::Initialize()") {
initialize = method;
methods++;
}
else if (method.FullName == "System.Void " + typeName + "::PostInitialize()") {
postInitialize = method;
methods++;
}
else if (method.FullName == "System.IntPtr " + typeName + "::Load()") {
load = method;
methods++;
}
}
if (methods == 0 || (methods == 1 && initialize != null))
continue;
stringDecrypterMethod = cs;
initializeMethod = initialize;
postInitializeMethod = postInitialize;
loadMethod = load;
cliSecureRtType = type;
return true;
}
return false;
}
bool findOld() {
foreach (var cctor in DeobUtils.getInitCctors(module, 3)) {
foreach (var calledMethod in DotNetUtils.getCalledMethods(module, cctor)) {
var type = calledMethod.DeclaringType;
if (!hasPinvokeMethod(type, "_Initialize"))
continue;
if (!hasPinvokeMethod(type, "_Initialize64"))
continue;
initializeMethod = calledMethod;
cliSecureRtType = type;
return true;
}
}
return false;
}
bool findNativeCode() {
if ((module.Attributes & ModuleAttributes.ILOnly) != 0)
return false;
using (var file = new FileStream(module.FullyQualifiedName, FileMode.Open, FileAccess.Read, FileShare.Read)) {
var peImage = new PeImage(file);
return foundSig = MethodsDecrypter.detect(peImage);
}
}
static bool hasPinvokeMethod(TypeDefinition type, string methodName) {
if (type == null)
return false;
foreach (var method in type.Methods) {
if (method.PInvokeInfo == null)
continue;
if (method.PInvokeInfo.EntryPoint == methodName)
return true;
}
return false;
}
public bool isAtLeastVersion50() {
return hasPinvokeMethod(cliSecureRtType, "LoadLibraryA");
}
}
}