de4dot-cex/de4dot.code/deobfuscators/dotNET_Reactor/v4/ProxyCallFixer.cs
2012-07-07 01:59:03 +02:00

109 lines
3.3 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 Mono.Cecil;
using Mono.Cecil.Cil;
using de4dot.blocks;
namespace de4dot.code.deobfuscators.dotNET_Reactor.v4 {
class ProxyCallFixer : ProxyCallFixer3 {
ISimpleDeobfuscator simpleDeobfuscator;
public ProxyCallFixer(ModuleDefinition module, ISimpleDeobfuscator simpleDeobfuscator)
: base(module) {
this.simpleDeobfuscator = simpleDeobfuscator;
}
public void findDelegateCreator() {
foreach (var type in module.Types) {
var creatorMethod = checkType(type);
if (creatorMethod == null)
continue;
setDelegateCreatorMethod(creatorMethod);
return;
}
}
static readonly string[] requiredFields = new string[] {
"System.Reflection.Module",
};
static MethodDefinition checkType(TypeDefinition type) {
if (!new FieldTypes(type).exactly(requiredFields))
return null;
if (DotNetUtils.getMethod(type, ".cctor") == null)
return null;
return checkMethods(type);
}
static MethodDefinition checkMethods(TypeDefinition type) {
MethodDefinition creatorMethod = null;
foreach (var method in type.Methods) {
if (method.Body == null)
return null;
if (method.Name == ".cctor" || method.Name == ".ctor")
continue;
if (!DotNetUtils.isMethod(method, "System.Void", "(System.Int32)"))
return null;
if (!DeobUtils.hasInteger(method, 0x02000000))
return null;
if (!DeobUtils.hasInteger(method, 0x06000000))
return null;
creatorMethod = method;
}
return creatorMethod;
}
protected override object checkCctor(ref TypeDefinition type, MethodDefinition cctor) {
simpleDeobfuscator.deobfuscate(cctor);
var realType = getDelegateType(cctor);
if (realType == null)
return null;
type = realType;
return this;
}
TypeDefinition getDelegateType(MethodDefinition method) {
var instrs = method.Body.Instructions;
for (int i = 0; i < instrs.Count - 1; i++) {
var ldci4 = instrs[i];
if (!DotNetUtils.isLdcI4(ldci4))
continue;
var call = instrs[i + 1];
if (call.OpCode.Code != Code.Call)
continue;
var calledMethod = call.Operand as MethodDefinition;
if (calledMethod == null || !isDelegateCreatorMethod(calledMethod))
continue;
return module.LookupToken(0x02000000 + DotNetUtils.getLdcI4Value(ldci4)) as TypeDefinition;
}
return null;
}
protected override void getCallInfo(object context, FieldDefinition field, out MethodReference calledMethod, out OpCode callOpcode) {
calledMethod = module.LookupToken(0x06000000 + field.MetadataToken.ToInt32()) as MethodReference;
callOpcode = OpCodes.Call;
}
}
}