de4dot-cex/de4dot.code/deobfuscators/dotNET_Reactor/v3/LibAssemblyResolver.cs

130 lines
3.7 KiB
C#

/*
Copyright (C) 2011 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 Mono.Cecil;
using Mono.Cecil.Cil;
using de4dot.blocks;
namespace de4dot.code.deobfuscators.dotNET_Reactor.v3 {
// Find the assembly resolver that's used in lib mode (3.8+)
class LibAssemblyResolver {
ModuleDefinition module;
MethodDefinition initMethod;
List<EmbeddedResource> resources = new List<EmbeddedResource>();
public TypeDefinition Type {
get { return initMethod == null ? null : initMethod.DeclaringType; }
}
public MethodDefinition InitMethod {
get { return initMethod; }
}
public IEnumerable<EmbeddedResource> Resources {
get { return resources; }
}
public LibAssemblyResolver(ModuleDefinition module) {
this.module = module;
}
public void find(ISimpleDeobfuscator simpleDeobfuscator, IDeobfuscator deob) {
if (checkInitMethod(DotNetUtils.getMethod(DotNetUtils.getModuleType(module), ".cctor"), simpleDeobfuscator, deob))
return;
if (checkInitMethod(module.EntryPoint, simpleDeobfuscator, deob))
return;
}
bool checkInitMethod(MethodDefinition checkMethod, ISimpleDeobfuscator simpleDeobfuscator, IDeobfuscator deob) {
var requiredFields = new string[] {
"System.Collections.Hashtable",
"System.Boolean",
};
foreach (var tuple in DotNetUtils.getCalledMethods(module, checkMethod)) {
var method = tuple.Item2;
if (method.Body == null)
continue;
if (!method.IsStatic)
continue;
if (!DotNetUtils.isMethod(method, "System.Void", "()"))
continue;
var type = method.DeclaringType;
if (!new FieldTypes(type).exactly(requiredFields))
continue;
var ctor = DotNetUtils.getMethod(type, ".ctor");
if (ctor == null)
continue;
var handler = getHandler(ctor);
if (handler == null)
continue;
simpleDeobfuscator.decryptStrings(handler, deob);
var resourcePrefix = getResourcePrefix(handler);
if (resourcePrefix == null)
continue;
for (int i = 0; ; i++) {
var resource = DotNetUtils.getResource(module, resourcePrefix + i.ToString("D5")) as EmbeddedResource;
if (resource == null)
break;
resources.Add(resource);
}
initMethod = method;
return true;
}
return false;
}
MethodDefinition getHandler(MethodDefinition ctor) {
if (ctor == null || ctor.Body == null)
return null;
foreach (var instr in ctor.Body.Instructions) {
if (instr.OpCode.Code != Code.Ldftn)
continue;
var handler = instr.Operand as MethodReference;
if (handler == null)
continue;
if (!DotNetUtils.isMethod(handler, "System.Reflection.Assembly", "(System.Object,System.ResolveEventArgs)"))
continue;
var handlerDef = DotNetUtils.getMethod(module, handler);
if (handlerDef == null)
continue;
return handlerDef;
}
return null;
}
string getResourcePrefix(MethodDefinition handler) {
foreach (var s in DotNetUtils.getCodeStrings(handler)) {
var resource = DotNetUtils.getResource(module, s + "00000") as EmbeddedResource;
if (resource != null)
return s;
}
return null;
}
}
}