337 lines
9.5 KiB
C#
337 lines
9.5 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;
|
|
using System.Collections.Generic;
|
|
using Mono.Cecil;
|
|
using Mono.Cecil.Cil;
|
|
using de4dot.blocks;
|
|
|
|
namespace de4dot.code.deobfuscators.DeepSea {
|
|
class ResourceResolver : ResolverBase {
|
|
Data30 data30;
|
|
Data40 data40;
|
|
Data41 data41;
|
|
ResourceVersion version = ResourceVersion.Unknown;
|
|
|
|
enum ResourceVersion {
|
|
Unknown,
|
|
V3,
|
|
V40,
|
|
V41,
|
|
}
|
|
|
|
class Data30 {
|
|
public EmbeddedResource resource;
|
|
}
|
|
|
|
class Data40 {
|
|
public FieldDefinition resourceField;
|
|
public MethodDefinition getDataMethod;
|
|
public int magic;
|
|
}
|
|
|
|
class Data41 {
|
|
public FieldDefinition resourceField;
|
|
public MethodDefinition resolveHandler2;
|
|
public int magic;
|
|
public bool isTrial;
|
|
}
|
|
|
|
class HandlerInfo {
|
|
public MethodDefinition handler;
|
|
public IList<object> args;
|
|
|
|
public HandlerInfo(MethodDefinition handler, IList<object> args) {
|
|
this.handler = handler;
|
|
this.args = args;
|
|
}
|
|
}
|
|
|
|
public MethodDefinition GetDataMethod {
|
|
get { return data40 != null ? data40.getDataMethod : null; }
|
|
}
|
|
|
|
public EmbeddedResource Resource {
|
|
get { return data30 != null ? data30.resource : null; }
|
|
}
|
|
|
|
public ResourceResolver(ModuleDefinition module, ISimpleDeobfuscator simpleDeobfuscator, IDeobfuscator deob)
|
|
: base(module, simpleDeobfuscator, deob) {
|
|
}
|
|
|
|
protected override bool checkResolverInitMethodInternal(MethodDefinition resolverInitMethod) {
|
|
return DotNetUtils.callsMethod(resolverInitMethod, "System.Void System.AppDomain::add_ResourceResolve(System.ResolveEventHandler)");
|
|
}
|
|
|
|
protected override bool checkHandlerMethodDesktopInternal(MethodDefinition handler) {
|
|
if (checkHandlerV3(handler)) {
|
|
version = ResourceVersion.V3;
|
|
return true;
|
|
}
|
|
|
|
simpleDeobfuscator.deobfuscate(handler);
|
|
if ((data40 = checkHandlerV40(handler)) != null) {
|
|
version = ResourceVersion.V40;
|
|
return true;
|
|
}
|
|
|
|
var info = getHandlerArgs41(handler);
|
|
Data41 data41Tmp;
|
|
if (info != null && checkHandlerV41(info, out data41Tmp)) {
|
|
version = ResourceVersion.V41;
|
|
data41 = data41Tmp;
|
|
return true;
|
|
}
|
|
|
|
return false;
|
|
}
|
|
|
|
HandlerInfo getHandlerArgs41(MethodDefinition handler) {
|
|
var instrs = handler.Body.Instructions;
|
|
for (int i = 0; i < instrs.Count; i++) {
|
|
var instr = instrs[i];
|
|
if (instr.OpCode.Code != Code.Call)
|
|
continue;
|
|
var calledMethod = instr.Operand as MethodDefinition;
|
|
if (calledMethod == null)
|
|
continue;
|
|
var args = DsUtils.getArgValues(instrs, i);
|
|
if (args == null)
|
|
continue;
|
|
|
|
return new HandlerInfo(calledMethod, args);
|
|
}
|
|
return null;
|
|
}
|
|
|
|
bool checkHandlerV41(HandlerInfo info, out Data41 data41) {
|
|
data41 = new Data41();
|
|
data41.resolveHandler2 = info.handler;
|
|
data41.resourceField = getLdtokenField(info.handler);
|
|
if (data41.resourceField == null)
|
|
return false;
|
|
int magicArgIndex = getMagicArgIndex41Retail(info.handler);
|
|
if (magicArgIndex < 0) {
|
|
magicArgIndex = getMagicArgIndex41Trial(info.handler);
|
|
data41.isTrial = true;
|
|
}
|
|
var asmVer = module.Assembly.Name.Version;
|
|
if (magicArgIndex < 0 || magicArgIndex >= info.args.Count)
|
|
return false;
|
|
var val = info.args[magicArgIndex];
|
|
if (!(val is int))
|
|
return false;
|
|
if (data41.isTrial)
|
|
data41.magic = (int)val >> 3;
|
|
else
|
|
data41.magic = ((asmVer.Major << 3) | (asmVer.Minor << 2) | asmVer.Revision) - (int)val;
|
|
return true;
|
|
}
|
|
|
|
static int getMagicArgIndex41Retail(MethodDefinition method) {
|
|
var instrs = method.Body.Instructions;
|
|
for (int i = 0; i < instrs.Count - 3; i++) {
|
|
var add = instrs[i];
|
|
if (add.OpCode.Code != Code.Add)
|
|
continue;
|
|
var ldarg = instrs[i + 1];
|
|
if (!DotNetUtils.isLdarg(ldarg))
|
|
continue;
|
|
var sub = instrs[i + 2];
|
|
if (sub.OpCode.Code != Code.Sub)
|
|
continue;
|
|
var ldci4 = instrs[i + 3];
|
|
if (!DotNetUtils.isLdcI4(ldci4) || DotNetUtils.getLdcI4Value(ldci4) != 0xFF)
|
|
continue;
|
|
|
|
return DotNetUtils.getArgIndex(ldarg);
|
|
}
|
|
return -1;
|
|
}
|
|
|
|
static int getMagicArgIndex41Trial(MethodDefinition method) {
|
|
var instrs = method.Body.Instructions;
|
|
for (int i = 0; i < instrs.Count - 2; i++) {
|
|
var ldarg = instrs[i];
|
|
if (!DotNetUtils.isLdarg(ldarg))
|
|
continue;
|
|
if (!DotNetUtils.isLdcI4(instrs[i + 1]))
|
|
continue;
|
|
if (instrs[i + 2].OpCode.Code != Code.Shr)
|
|
continue;
|
|
|
|
return DotNetUtils.getArgIndex(ldarg);
|
|
}
|
|
return -1;
|
|
}
|
|
|
|
static FieldDefinition getLdtokenField(MethodDefinition method) {
|
|
foreach (var instr in method.Body.Instructions) {
|
|
if (instr.OpCode.Code != Code.Ldtoken)
|
|
continue;
|
|
var field = instr.Operand as FieldDefinition;
|
|
if (field == null || field.InitialValue == null || field.InitialValue.Length == 0)
|
|
continue;
|
|
|
|
return field;
|
|
}
|
|
return null;
|
|
}
|
|
|
|
static string[] handlerLocalTypes_V3 = new string[] {
|
|
"System.AppDomain",
|
|
"System.Byte[]",
|
|
"System.Collections.Generic.Dictionary`2<System.String,System.String>",
|
|
"System.IO.Compression.DeflateStream",
|
|
"System.IO.MemoryStream",
|
|
"System.IO.Stream",
|
|
"System.Reflection.Assembly",
|
|
"System.String",
|
|
"System.String[]",
|
|
};
|
|
static bool checkHandlerV3(MethodDefinition handler) {
|
|
return new LocalTypes(handler).all(handlerLocalTypes_V3);
|
|
}
|
|
|
|
static Data40 checkHandlerV40(MethodDefinition handler) {
|
|
var data40 = new Data40();
|
|
|
|
var instrs = handler.Body.Instructions;
|
|
for (int i = 0; i < instrs.Count; i++) {
|
|
int index = i;
|
|
|
|
if (instrs[index++].OpCode.Code != Code.Ldarg_1)
|
|
continue;
|
|
|
|
var ldtoken = instrs[index++];
|
|
if (ldtoken.OpCode.Code != Code.Ldtoken)
|
|
continue;
|
|
var field = ldtoken.Operand as FieldDefinition;
|
|
|
|
string methodSig = "(System.ResolveEventArgs,System.RuntimeFieldHandle,System.Int32,System.String,System.Int32)";
|
|
var method = ldtoken.Operand as MethodDefinition;
|
|
if (method != null) {
|
|
// >= 4.0.4
|
|
if (!DotNetUtils.isMethod(method, "System.Byte[]", "()"))
|
|
continue;
|
|
field = getResourceField(method);
|
|
methodSig = "(System.ResolveEventArgs,System.RuntimeMethodHandle,System.Int32,System.String,System.Int32)";
|
|
}
|
|
else {
|
|
// 4.0.1.18 .. 4.0.3
|
|
}
|
|
|
|
if (field == null || field.InitialValue == null || field.InitialValue.Length == 0)
|
|
continue;
|
|
|
|
var ldci4_len = instrs[index++];
|
|
if (!DotNetUtils.isLdcI4(ldci4_len))
|
|
continue;
|
|
if (DotNetUtils.getLdcI4Value(ldci4_len) != field.InitialValue.Length)
|
|
continue;
|
|
|
|
if (instrs[index++].OpCode.Code != Code.Ldstr)
|
|
continue;
|
|
|
|
var ldci4_magic = instrs[index++];
|
|
if (!DotNetUtils.isLdcI4(ldci4_magic))
|
|
continue;
|
|
data40.magic = DotNetUtils.getLdcI4Value(ldci4_magic);
|
|
|
|
var call = instrs[index++];
|
|
if (call.OpCode.Code == Code.Tail)
|
|
call = instrs[index++];
|
|
if (call.OpCode.Code != Code.Call)
|
|
continue;
|
|
if (!DotNetUtils.isMethod(call.Operand as MethodReference, "System.Reflection.Assembly", methodSig))
|
|
continue;
|
|
|
|
data40.resourceField = field;
|
|
data40.getDataMethod = method;
|
|
return data40;
|
|
}
|
|
|
|
return null;
|
|
}
|
|
|
|
static FieldDefinition getResourceField(MethodDefinition method) {
|
|
foreach (var instr in method.Body.Instructions) {
|
|
if (instr.OpCode.Code != Code.Ldtoken)
|
|
continue;
|
|
var field = instr.Operand as FieldDefinition;
|
|
if (field == null || field.InitialValue == null || field.InitialValue.Length == 0)
|
|
continue;
|
|
return field;
|
|
}
|
|
return null;
|
|
}
|
|
|
|
public void initialize() {
|
|
if (resolveHandler == null)
|
|
return;
|
|
|
|
if (version == ResourceVersion.V3) {
|
|
simpleDeobfuscator.deobfuscate(resolveHandler);
|
|
simpleDeobfuscator.decryptStrings(resolveHandler, deob);
|
|
data30 = new Data30();
|
|
data30.resource = DeobUtils.getEmbeddedResourceFromCodeStrings(module, resolveHandler);
|
|
if (data30.resource == null) {
|
|
Log.w("Could not find resource of encrypted resources");
|
|
return;
|
|
}
|
|
}
|
|
}
|
|
|
|
public bool mergeResources(out EmbeddedResource rsrc) {
|
|
rsrc = null;
|
|
|
|
switch (version) {
|
|
case ResourceVersion.V3:
|
|
if (data30.resource == null)
|
|
return false;
|
|
|
|
DeobUtils.decryptAndAddResources(module, data30.resource.Name, () => decryptResourceV3(data30.resource));
|
|
rsrc = data30.resource;
|
|
return true;
|
|
|
|
case ResourceVersion.V40:
|
|
return decryptResource(data40.resourceField, data40.magic);
|
|
|
|
case ResourceVersion.V41:
|
|
return decryptResource(data41.resourceField, data41.magic);
|
|
|
|
default:
|
|
return true;
|
|
}
|
|
}
|
|
|
|
bool decryptResource(FieldDefinition resourceField, int magic) {
|
|
if (resourceField == null)
|
|
return false;
|
|
|
|
string name = string.Format("Embedded data field {0:X8} RVA {1:X8}", resourceField.MetadataToken.ToInt32(), resourceField.RVA);
|
|
DeobUtils.decryptAndAddResources(module, name, () => decryptResourceV4(resourceField.InitialValue, magic));
|
|
resourceField.InitialValue = new byte[1];
|
|
resourceField.FieldType = module.TypeSystem.Byte;
|
|
return true;
|
|
}
|
|
}
|
|
}
|