134 lines
4.1 KiB
C#
134 lines
4.1 KiB
C#
/*
|
|
Copyright (C) 2011-2015 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 System.Text;
|
|
using dnlib.DotNet;
|
|
using dnlib.DotNet.Emit;
|
|
using de4dot.blocks;
|
|
|
|
namespace de4dot.code.deobfuscators.Babel_NET {
|
|
static class BabelUtils {
|
|
public static EmbeddedResource FindEmbeddedResource(ModuleDefMD module, TypeDef decrypterType) {
|
|
return FindEmbeddedResource(module, decrypterType, (method) => { });
|
|
}
|
|
|
|
public static EmbeddedResource FindEmbeddedResource(ModuleDefMD module, TypeDef decrypterType, ISimpleDeobfuscator simpleDeobfuscator, IDeobfuscator deob) {
|
|
return FindEmbeddedResource(module, decrypterType, (method) => {
|
|
simpleDeobfuscator.Deobfuscate(method);
|
|
simpleDeobfuscator.DecryptStrings(method, deob);
|
|
});
|
|
}
|
|
|
|
public static EmbeddedResource FindEmbeddedResource(ModuleDefMD module, TypeDef decrypterType, Action<MethodDef> fixMethod) {
|
|
foreach (var method in decrypterType.Methods) {
|
|
if (!DotNetUtils.IsMethod(method, "System.String", "()"))
|
|
continue;
|
|
if (!method.IsStatic)
|
|
continue;
|
|
fixMethod(method);
|
|
var resource = FindEmbeddedResource1(module, method) ?? FindEmbeddedResource2(module, method);
|
|
if (resource != null)
|
|
return resource;
|
|
}
|
|
return null;
|
|
}
|
|
|
|
static EmbeddedResource FindEmbeddedResource1(ModuleDefMD module, MethodDef method) {
|
|
foreach (var s in DotNetUtils.GetCodeStrings(method)) {
|
|
var resource = DotNetUtils.GetResource(module, s) as EmbeddedResource;
|
|
if (resource != null)
|
|
return resource;
|
|
}
|
|
return null;
|
|
}
|
|
|
|
static EmbeddedResource FindEmbeddedResource2(ModuleDefMD module, MethodDef method) {
|
|
var strings = new List<string>(DotNetUtils.GetCodeStrings(method));
|
|
if (strings.Count != 1)
|
|
return null;
|
|
var encryptedString = strings[0];
|
|
|
|
int xorKey;
|
|
if (!GetXorKey2(method, out xorKey))
|
|
return null;
|
|
|
|
var sb = new StringBuilder(encryptedString.Length);
|
|
foreach (var c in encryptedString)
|
|
sb.Append((char)(c ^ xorKey));
|
|
return DotNetUtils.GetResource(module, sb.ToString()) as EmbeddedResource;
|
|
}
|
|
|
|
static bool GetXorKey2(MethodDef method, out int xorKey) {
|
|
var instrs = method.Body.Instructions;
|
|
for (int i = 0; i < instrs.Count - 2; i++) {
|
|
var ldelem = instrs[i];
|
|
if (ldelem.OpCode.Code != Code.Ldelem_U2)
|
|
continue;
|
|
|
|
var ldci4 = instrs[i + 1];
|
|
if (!ldci4.IsLdcI4())
|
|
continue;
|
|
|
|
if (instrs[i + 2].OpCode.Code != Code.Xor)
|
|
continue;
|
|
|
|
xorKey = ldci4.GetLdcI4Value();
|
|
return true;
|
|
}
|
|
|
|
xorKey = 0;
|
|
return false;
|
|
}
|
|
|
|
public static bool FindRegisterMethod(TypeDef type, out MethodDef regMethod, out MethodDef handler) {
|
|
foreach (var method in type.Methods) {
|
|
if (!method.IsStatic || method.Body == null)
|
|
continue;
|
|
if (method.Body.ExceptionHandlers.Count != 1)
|
|
continue;
|
|
|
|
foreach (var instr in method.Body.Instructions) {
|
|
if (instr.OpCode.Code != Code.Ldftn)
|
|
continue;
|
|
var handlerRef = instr.Operand as IMethod;
|
|
if (handlerRef == null)
|
|
continue;
|
|
if (!DotNetUtils.IsMethod(handlerRef, "System.Reflection.Assembly", "(System.Object,System.ResolveEventArgs)"))
|
|
continue;
|
|
if (!new SigComparer().Equals(type, handlerRef.DeclaringType))
|
|
continue;
|
|
handler = DotNetUtils.GetMethod(type, handlerRef);
|
|
if (handler == null)
|
|
continue;
|
|
if (handler.Body == null || handler.Body.ExceptionHandlers.Count != 1)
|
|
continue;
|
|
|
|
regMethod = method;
|
|
return true;
|
|
}
|
|
}
|
|
|
|
regMethod = null;
|
|
handler = null;
|
|
return false;
|
|
}
|
|
}
|
|
}
|