153 lines
4.2 KiB
C#
153 lines
4.2 KiB
C#
/*
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Copyright (C) 2011-2012 de4dot@gmail.com
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This file is part of de4dot.
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de4dot is free software: you can redistribute it and/or modify
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it under the terms of the GNU General Public License as published by
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the Free Software Foundation, either version 3 of the License, or
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(at your option) any later version.
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de4dot is distributed in the hope that it will be useful,
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but WITHOUT ANY WARRANTY; without even the implied warranty of
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MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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GNU General Public License for more details.
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You should have received a copy of the GNU General Public License
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along with de4dot. If not, see <http://www.gnu.org/licenses/>.
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*/
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using System;
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using System.Collections.Generic;
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using dot10.IO;
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using dot10.DotNet;
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using dot10.DotNet.Emit;
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using de4dot.blocks;
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namespace de4dot.code.deobfuscators.CryptoObfuscator {
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class ResourceResolver {
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ModuleDefMD module;
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ResourceDecrypter resourceDecrypter;
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TypeDef resolverType;
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MethodDef resolverMethod;
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ResolverVersion resolverVersion = ResolverVersion.V1;
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bool mergedIt = false;
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enum ResolverVersion {
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None,
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V1,
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V2,
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}
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public TypeDef Type {
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get { return resolverType; }
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}
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public MethodDef Method {
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get { return resolverMethod; }
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}
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public ResourceResolver(ModuleDefMD module, ResourceDecrypter resourceDecrypter) {
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this.module = module;
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this.resourceDecrypter = resourceDecrypter;
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}
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public void find() {
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var cctor = DotNetUtils.getModuleTypeCctor(module);
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if (cctor == null)
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return;
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foreach (var method in DotNetUtils.getCalledMethods(module, cctor)) {
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if (method.Name == ".cctor" || method.Name == ".ctor")
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continue;
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if (!method.IsStatic || !DotNetUtils.isMethod(method, "System.Void", "()"))
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continue;
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if (checkType(method))
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break;
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}
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}
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public EmbeddedResource mergeResources() {
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if (mergedIt)
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return null;
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var resource = DotNetUtils.getResource(module, getResourceNames()) as EmbeddedResource;
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if (resource == null)
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return null;
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DeobUtils.decryptAndAddResources(module, resource.Name.String, () => resourceDecrypter.decrypt(resource.Data.CreateStream()));
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mergedIt = true;
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return resource;
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}
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IEnumerable<string> getResourceNames() {
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var names = new List<string>();
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switch (resolverVersion) {
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case ResolverVersion.V1:
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names.Add(module.Assembly.Name.String);
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break;
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case ResolverVersion.V2:
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names.Add(string.Format("{0}{0}{0}", module.Assembly.Name.String));
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names.Add(string.Format("{0}&", module.Assembly.Name.String));
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break;
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default:
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throw new ApplicationException("Unknown version");
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}
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return names;
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}
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bool checkType(MethodDef initMethod) {
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if (!initMethod.HasBody)
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return false;
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if (DotNetUtils.findFieldType(initMethod.DeclaringType, "System.Reflection.Assembly", true) == null)
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return false;
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resolverVersion = checkSetupMethod(initMethod);
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if (resolverVersion == ResolverVersion.None)
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resolverVersion = checkSetupMethod(initMethod.DeclaringType.FindClassConstructor());
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if (resolverVersion == ResolverVersion.None)
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return false;
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resolverType = initMethod.DeclaringType;
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resolverMethod = initMethod;
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return true;
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}
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ResolverVersion checkSetupMethod(MethodDef setupMethod) {
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var instructions = setupMethod.Body.Instructions;
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int foundCount = 0;
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for (int i = 0; i < instructions.Count; i++) {
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var instrs = DotNetUtils.getInstructions(instructions, i, OpCodes.Ldnull, OpCodes.Ldftn, OpCodes.Newobj);
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if (instrs == null)
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continue;
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IMethod methodRef;
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var ldftn = instrs[1];
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var newobj = instrs[2];
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methodRef = ldftn.Operand as IMethod;
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if (methodRef == null || !new SigComparer().Equals(setupMethod.DeclaringType, methodRef.DeclaringType))
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continue;
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methodRef = newobj.Operand as IMethod;
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if (methodRef == null || methodRef.FullName != "System.Void System.ResolveEventHandler::.ctor(System.Object,System.IntPtr)")
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continue;
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foundCount++;
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}
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if (foundCount == 0)
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return ResolverVersion.None;
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switch (foundCount) {
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case 1: return ResolverVersion.V1;
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case 2: return ResolverVersion.V2;
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default: return ResolverVersion.None;
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}
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}
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}
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}
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