1234 lines
33 KiB
C#
1234 lines
33 KiB
C#
/*
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Copyright (C) 2011-2015 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 System.IO;
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using System.Text;
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using dnlib.DotNet;
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using dnlib.DotNet.Emit;
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using de4dot.blocks;
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using de4dot.blocks.cflow;
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namespace de4dot.code.deobfuscators.Eazfuscator_NET {
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class StringDecrypter : IDisposable {
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ModuleDefMD module;
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TypeDef stringType;
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MethodDef stringMethod;
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TypeDef dataDecrypterType;
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short s1, s2, s3;
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int i1, /*i2,*/ i3, i4, i5, i6;
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bool checkMinus2;
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bool usePublicKeyToken;
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int keyLen;
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byte[] theKey;
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int magic1;
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uint rldFlag, bytesFlag;
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EmbeddedResource encryptedResource;
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BinaryReader reader;
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DecrypterType decrypterType;
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StreamHelperType streamHelperType;
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EfConstantsReader stringMethodConsts;
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bool isV32OrLater;
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bool isV50OrLater;
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bool isV51OrLater;
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int? validStringDecrypterValue;
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DynamicDynocodeIterator dynocode;
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MethodDef realMethod;
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class StreamHelperType {
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public TypeDef type;
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public MethodDef readInt16Method;
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public MethodDef readInt32Method;
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public MethodDef readBytesMethod;
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public bool Detected {
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get {
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return readInt16Method != null &&
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readInt32Method != null &&
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readBytesMethod != null;
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}
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}
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public StreamHelperType(TypeDef type) {
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this.type = type;
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foreach (var method in type.Methods) {
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if (method.IsStatic || method.Body == null || method.IsPrivate || method.GenericParameters.Count > 0)
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continue;
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if (DotNetUtils.IsMethod(method, "System.Int16", "()"))
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readInt16Method = method;
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else if (DotNetUtils.IsMethod(method, "System.Int32", "()"))
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readInt32Method = method;
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else if (DotNetUtils.IsMethod(method, "System.Byte[]", "(System.Int32)"))
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readBytesMethod = method;
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}
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}
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}
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public int? ValidStringDecrypterValue {
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get { return validStringDecrypterValue; }
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}
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public TypeDef Type {
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get { return stringType; }
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}
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public EmbeddedResource Resource {
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get { return encryptedResource; }
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}
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public IEnumerable<TypeDef> Types {
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get {
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return new List<TypeDef> {
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stringType,
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dataDecrypterType,
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};
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}
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}
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public IEnumerable<TypeDef> DynocodeTypes {
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get { return dynocode.Types; }
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}
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public MethodDef Method {
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get { return stringMethod; }
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}
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public bool Detected {
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get { return stringType != null; }
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}
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/// <summary>
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/// In 5.0, the actual string decrypter method doesn't do much, calls a helper method which
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/// does most of the work (and is mostly the same as the stringMethod from 4.9 and below).
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/// </summary>
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public bool HasRealMethod {
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get { return realMethod != null; }
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}
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public MethodDef RealMethod {
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get { return (realMethod != null ? realMethod : stringMethod); }
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}
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public StringDecrypter(ModuleDefMD module, DecrypterType decrypterType) {
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this.module = module;
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this.decrypterType = decrypterType;
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}
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static bool CheckIfV32OrLater(TypeDef type) {
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int numInts = 0;
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foreach (var field in type.Fields) {
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if (field.FieldSig.GetFieldType().GetElementType() == ElementType.I4)
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numInts++;
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}
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return numInts >= 2;
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}
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public void Find() {
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foreach (var type in module.Types) {
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if (!CheckType(type))
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continue;
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foreach (var method in type.Methods) {
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if (!CheckDecrypterMethod(method))
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continue;
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// 5.0
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if (CheckIfHelperMethod(method)) {
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stringMethod = method;
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realMethod = GetRealDecrypterMethod(method);
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isV50OrLater = true;
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foreach (var inst in stringMethod.Body.Instructions) {
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if (inst.OpCode.Code == Code.Cgt_Un) {
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isV51OrLater = true;
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break;
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}
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}
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}
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else stringMethod = method;
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stringType = type;
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isV32OrLater = CheckIfV32OrLater(stringType);
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return;
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}
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}
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}
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static string[] requiredFieldTypes = new string[] {
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"System.Byte[]",
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"System.Int16",
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};
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bool CheckType(TypeDef type) {
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if (!new FieldTypes(type).All(requiredFieldTypes))
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return false;
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if (type.NestedTypes.Count == 0) {
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return DotNetUtils.FindFieldType(type, "System.IO.BinaryReader", true) != null &&
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DotNetUtils.FindFieldType(type, "System.Collections.Generic.Dictionary`2<System.Int32,System.String>", true) != null;
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}
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else if (type.NestedTypes.Count == 3) {
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streamHelperType = FindStreamHelperType(type);
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return streamHelperType != null;
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}
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else if (type.NestedTypes.Count == 1) {
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return type.NestedTypes[0].IsEnum;
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}
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else
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return false;
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}
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static string[] streamHelperTypeFields = new string[] {
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"System.IO.Stream",
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"System.Byte[]",
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};
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static StreamHelperType FindStreamHelperType(TypeDef type) {
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foreach (var field in type.Fields) {
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var nested = field.FieldSig.GetFieldType().TryGetTypeDef();
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if (nested == null)
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continue;
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if (nested.DeclaringType != type)
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continue;
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if (!new FieldTypes(nested).Exactly(streamHelperTypeFields))
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continue;
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var streamHelperType = new StreamHelperType(nested);
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if (!streamHelperType.Detected)
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continue;
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return streamHelperType;
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}
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return null;
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}
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static string[] requiredLocalTypes = new string[] {
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"System.Boolean",
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"System.Byte[]",
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"System.Char[]",
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"System.Int16",
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"System.Int32",
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"System.Reflection.Assembly",
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"System.String",
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};
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static bool CheckDecrypterMethod(MethodDef method) {
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if (method == null || !method.IsStatic || method.Body == null)
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return false;
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if (!DotNetUtils.IsMethod(method, "System.String", "(System.Int32)"))
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return false;
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if (!new LocalTypes(method).All(requiredLocalTypes))
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return false;
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foreach (var instr in method.Body.Instructions) {
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if (instr.OpCode != OpCodes.Callvirt)
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continue;
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var calledMethod = instr.Operand as IMethod;
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if (calledMethod != null && calledMethod.FullName == "System.IO.Stream System.Reflection.Assembly::GetManifestResourceStream(System.String)")
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return true;
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}
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return false;
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}
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/// <remarks>5.0</remarks>
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static bool CheckIfHelperMethod(MethodDef method) {
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// Helper method will be `private static`, instead of `internal static`
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return method.DeclaringType.Methods.Count == 4 && !method.IsAssembly;
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}
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/// <summary>
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/// Get the real decrypter method from a found helper method.
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/// </summary>
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/// <remarks>5.0</remarks>
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static MethodDef GetRealDecrypterMethod(MethodDef helper) {
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var methods = helper.DeclaringType.Methods;
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var sigComparer = new SigComparer();
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foreach (var method in methods) {
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if (method.MDToken != helper.MDToken &&
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method.IsAssembly &&
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sigComparer.Equals(method.MethodSig, helper.MethodSig))
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return method;
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}
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return null;
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}
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public void Initialize(ISimpleDeobfuscator simpleDeobfuscator) {
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if (stringType == null)
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return;
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if (!FindConstants(simpleDeobfuscator)) {
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if (encryptedResource == null)
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Logger.w("Could not find encrypted resource. Strings cannot be decrypted.");
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else
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Logger.w("Can't decrypt strings. Possibly a new Eazfuscator.NET version.");
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return;
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}
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}
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bool FindConstants(ISimpleDeobfuscator simpleDeobfuscator) {
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dynocode = new DynamicDynocodeIterator();
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simpleDeobfuscator.Deobfuscate(stringMethod);
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stringMethodConsts = new EfConstantsReader(stringMethod);
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if (!FindResource(stringMethod))
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return false;
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checkMinus2 = isV32OrLater || DeobUtils.HasInteger(stringMethod, -2);
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usePublicKeyToken = CallsGetPublicKeyToken(stringMethod);
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var int64Method = FindInt64Method(stringMethod);
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if (int64Method != null)
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decrypterType.Type = int64Method.DeclaringType;
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if (!FindShorts())
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return false;
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if (!FindInt3())
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return false;
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if (!FindInt4())
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return false;
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if (checkMinus2 && !FindInt5())
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return false;
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// The method body of the data decrypter method has been moved into
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// the string decrypter helper method in 5.0
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if (!isV50OrLater) {
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dataDecrypterType = FindDataDecrypterType(stringMethod);
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if (dataDecrypterType == null)
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return false;
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}
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if (isV32OrLater) {
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bool initializedAll;
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int index = FindInitIntsIndex(stringMethod, out initializedAll);
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var cctor = stringType.FindStaticConstructor();
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if (!initializedAll && cctor != null) {
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simpleDeobfuscator.Deobfuscate(cctor);
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if (!FindIntsCctor(cctor))
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return false;
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}
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if (decrypterType.Detected && !decrypterType.Initialize())
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return false;
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if (!isV50OrLater) {
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decrypterType.ShiftConsts = new List<int> { 24, 16, 8, 0, 16, 8, 0, 24 };
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}
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else {
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List<int> shiftConsts;
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if (!FindShiftInts(decrypterType.Int64Method, out shiftConsts))
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return false;
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decrypterType.ShiftConsts = shiftConsts;
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}
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if (!FindInts(index))
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return false;
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}
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InitializeFlags();
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Initialize();
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return true;
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}
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void InitializeFlags() {
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if (!isV32OrLater) {
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rldFlag = 0x40000000;
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bytesFlag = 0x80000000;
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return;
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}
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var instrs = stringMethod.Body.Instructions;
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for (int i = 0; i < instrs.Count; i++) {
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var ldci4 = instrs[i];
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if (!stringMethodConsts.IsLoadConstantInt32(ldci4))
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continue;
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int index = i, tmp;
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if (!stringMethodConsts.GetInt32(ref index, out tmp) || !IsFlagsMask(tmp))
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continue;
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if (FindFlags(i))
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return;
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}
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throw new ApplicationException("Could not find string decrypter flags");
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}
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static bool IsFlagsMask(int value) {
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return value == 0x1FFFFFFF || value == 0x0FFFFFFF;
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}
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class FlagsInfo {
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public Local Local { get; set; }
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public uint Value { get; set; }
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public int Offset { get; set; }
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public FlagsInfo(Local local, uint value, int offset) {
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Local = local;
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Value = value;
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Offset = offset;
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}
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}
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bool FindFlags(int index) {
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var flags = FindFlags2(index);
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if (flags == null)
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return false;
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flags.Sort((a, b) => a.Offset.CompareTo(b.Offset));
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rldFlag = flags[0].Value;
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bytesFlag = flags[1].Value;
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return true;
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}
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List<FlagsInfo> FindFlags2(int index) {
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var flags = new List<FlagsInfo>(3);
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for (int i = index - 1; i >= 0; i--) {
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var instr = stringMethod.Body.Instructions[i];
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if (instr.OpCode.FlowControl != FlowControl.Next)
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break;
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if (!stringMethodConsts.IsLoadConstantInt32(instr))
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continue;
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int index2 = i, value;
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if (!stringMethodConsts.GetInt32(ref index2, out value))
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continue;
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if ((uint)value != 0x80000000 && value != 0x40000000 && value != 0x20000000)
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continue;
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var local = GetFlagsLocal(stringMethod, index2);
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if (local == null)
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continue;
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int offset = GetFlagsOffset(stringMethod, index2, local);
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if (offset < 0)
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continue;
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flags.Add(new FlagsInfo(local, (uint)value, offset));
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if (flags.Count != 3)
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continue;
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return flags;
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}
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return null;
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}
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static int GetFlagsOffset(MethodDef method, int index, Local local) {
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var instrs = method.Body.Instructions;
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for (; index < instrs.Count; index++) {
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var ldloc = instrs[index];
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if (!ldloc.IsLdloc())
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continue;
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if (ldloc.GetLocal(method.Body.Variables) != local)
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continue;
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return index;
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}
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return -1;
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}
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Local GetFlagsLocal(MethodDef method, int index) {
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if (isV51OrLater)
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return GetFlagsLocalNew(method, index);
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return GetFlagsLocalOld(method, index);
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}
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// <= 5.0
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static Local GetFlagsLocalOld(MethodDef method, int index) {
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var instrs = method.Body.Instructions;
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if (index + 5 >= instrs.Count)
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return null;
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if (instrs[index++].OpCode.Code != Code.And)
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return null;
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if (instrs[index++].OpCode.Code != Code.Ldc_I4_0)
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return null;
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if (instrs[index++].OpCode.Code != Code.Ceq)
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return null;
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if (instrs[index++].OpCode.Code != Code.Ldc_I4_0)
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return null;
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if (instrs[index++].OpCode.Code != Code.Ceq)
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return null;
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var stloc = instrs[index++];
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if (!stloc.IsStloc())
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return null;
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return stloc.GetLocal(method.Body.Variables);
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}
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// 5.1+
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// Uses different OpCodes
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static Local GetFlagsLocalNew(MethodDef method, int index) {
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var instrs = method.Body.Instructions;
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if (index + 5 >= instrs.Count)
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return null;
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if (instrs[index++].OpCode.Code != Code.And)
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return null;
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if (instrs[index++].OpCode.Code != Code.Ldc_I4_0)
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return null;
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if (instrs[index++].OpCode.Code != Code.Cgt_Un)
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return null;
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var stloc = instrs[index++];
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if (!stloc.IsStloc())
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return null;
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return stloc.GetLocal(method.Body.Variables);
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}
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void Initialize() {
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reader = new BinaryReader(encryptedResource.GetResourceStream());
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short len = (short)(reader.ReadInt16() ^ s1);
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if (len != 0)
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theKey = reader.ReadBytes(len);
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else
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keyLen = reader.ReadInt16() ^ s2;
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}
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public string Decrypt(int val) {
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validStringDecrypterValue = val;
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while (true) {
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int offset = magic1 ^ i3 ^ val ^ i6;
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reader.BaseStream.Position = offset;
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byte[] tmpKey;
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if (theKey == null) {
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tmpKey = reader.ReadBytes(keyLen == -1 ? (short)(reader.ReadInt16() ^ s3 ^ offset) : keyLen);
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if (isV32OrLater) {
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for (int i = 0; i < tmpKey.Length; i++)
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tmpKey[i] ^= (byte)(magic1 >> ((i & 3) << 3));
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}
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}
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else
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tmpKey = theKey;
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int flags = i4 ^ magic1 ^ offset ^ reader.ReadInt32();
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if (checkMinus2 && flags == -2) {
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var ary2 = reader.ReadBytes(4);
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val = -(magic1 ^ i5) ^ (ary2[2] | (ary2[0] << 8) | (ary2[3] << 16) | (ary2[1] << 24));
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continue;
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}
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var bytes = reader.ReadBytes(flags & 0x1FFFFFFF);
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Decrypt1(bytes, tmpKey);
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var pkt = PublicKeyBase.ToPublicKeyToken(module.Assembly.PublicKey);
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if (usePublicKeyToken && !PublicKeyBase.IsNullOrEmpty2(pkt)) {
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for (int i = 0; i < bytes.Length; i++)
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bytes[i] ^= (byte)((pkt.Data[i & 7] >> 5) + (pkt.Data[i & 7] << 3));
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}
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if ((flags & rldFlag) != 0)
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bytes = rld(bytes);
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if ((flags & bytesFlag) != 0) {
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var sb = new StringBuilder(bytes.Length);
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foreach (var b in bytes)
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sb.Append((char)b);
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return sb.ToString();
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}
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else
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return Encoding.Unicode.GetString(bytes);
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}
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}
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static byte[] rld(byte[] src) {
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var dst = new byte[src[2] + (src[3] << 8) + (src[0] << 16) + (src[1] << 24)];
|
|
int srcIndex = 4;
|
|
int dstIndex = 0;
|
|
int flags = 0;
|
|
int bit = 128;
|
|
while (dstIndex < dst.Length) {
|
|
bit <<= 1;
|
|
if (bit == 256) {
|
|
bit = 1;
|
|
flags = src[srcIndex++];
|
|
}
|
|
|
|
if ((flags & bit) == 0) {
|
|
dst[dstIndex++] = src[srcIndex++];
|
|
continue;
|
|
}
|
|
|
|
int numBytes = (src[srcIndex] >> 2) + 3;
|
|
int copyIndex = dstIndex - ((src[srcIndex + 1] + (src[srcIndex] << 8)) & 0x3FF);
|
|
if (copyIndex < 0)
|
|
break;
|
|
while (dstIndex < dst.Length && numBytes-- > 0)
|
|
dst[dstIndex++] = dst[copyIndex++];
|
|
srcIndex += 2;
|
|
}
|
|
|
|
return dst;
|
|
}
|
|
|
|
static void Decrypt1(byte[] dest, byte[] key) {
|
|
byte b = (byte)((key[1] + 7) ^ (dest.Length + 11));
|
|
uint lcg = (uint)((key[0] | (key[2] << 8)) + (b << 3));
|
|
b += 3;
|
|
ushort xn = 0;
|
|
for (int i = 0; i < dest.Length; i++) {
|
|
if ((i & 1) == 0) {
|
|
lcg = LcgNext(lcg);
|
|
xn = (ushort)(lcg >> 16);
|
|
}
|
|
byte tmp = dest[i];
|
|
dest[i] ^= (byte)(key[1] ^ xn ^ b);
|
|
b = (byte)(tmp + 3);
|
|
xn >>= 8;
|
|
}
|
|
}
|
|
|
|
static uint LcgNext(uint lcg) {
|
|
return lcg * 214013 + 2531011;
|
|
}
|
|
|
|
bool FindResource(MethodDef method) {
|
|
encryptedResource = FindResourceFromCodeString(method) ??
|
|
FindResourceFromStringBuilder(method);
|
|
return encryptedResource != null;
|
|
}
|
|
|
|
EmbeddedResource FindResourceFromCodeString(MethodDef method) {
|
|
return DotNetUtils.GetResource(module, DotNetUtils.GetCodeStrings(method)) as EmbeddedResource;
|
|
}
|
|
|
|
EmbeddedResource FindResourceFromStringBuilder(MethodDef method) {
|
|
int startIndex = EfUtils.FindOpCodeIndex(method, 0, Code.Newobj, "System.Void System.Text.StringBuilder::.ctor()");
|
|
if (startIndex < 0)
|
|
return null;
|
|
int endIndex = EfUtils.FindOpCodeIndex(method, startIndex, Code.Call, "System.String System.Text.StringBuilder::ToString()");
|
|
if (endIndex < 0)
|
|
return null;
|
|
|
|
var sb = new StringBuilder();
|
|
var instrs = method.Body.Instructions;
|
|
int val = 0, shift = 0;
|
|
for (int i = startIndex; i < endIndex; i++) {
|
|
var instr = instrs[i];
|
|
if (instr.OpCode.Code == Code.Call && instr.Operand.ToString() == "System.Text.StringBuilder System.Text.StringBuilder::Append(System.Char)") {
|
|
sb.Append((char)(val >> shift));
|
|
shift = 0;
|
|
}
|
|
if (stringMethodConsts.IsLoadConstantInt32(instr)) {
|
|
int tmp;
|
|
if (!stringMethodConsts.GetInt32(ref i, out tmp))
|
|
break;
|
|
if (i >= endIndex)
|
|
break;
|
|
|
|
var next = instrs[i];
|
|
if (next.OpCode.Code == Code.Shr)
|
|
shift = tmp;
|
|
else {
|
|
val = tmp;
|
|
shift = 0;
|
|
}
|
|
}
|
|
}
|
|
|
|
return DotNetUtils.GetResource(module, sb.ToString()) as EmbeddedResource;
|
|
}
|
|
|
|
bool FindShiftInts(MethodDef method, out List<int> bytes) {
|
|
var instrs = method.Body.Instructions;
|
|
var constantsReader = new EfConstantsReader(method);
|
|
bytes = new List<int>(8);
|
|
|
|
for (int i = 0; i < instrs.Count - 4; i++) {
|
|
if (bytes.Count >= 8)
|
|
return true;
|
|
|
|
var ldloc1 = instrs[i];
|
|
if (ldloc1.OpCode.Code != Code.Ldloc_1)
|
|
continue;
|
|
|
|
var ldlocs = instrs[i + 1];
|
|
if (ldlocs.OpCode.Code != Code.Ldloc_S)
|
|
continue;
|
|
|
|
var maybe = instrs[i + 2];
|
|
if (maybe.OpCode.Code == Code.Conv_U1) {
|
|
var callvirt = instrs[i + 3];
|
|
if (callvirt.OpCode.Code != Code.Callvirt)
|
|
return false;
|
|
|
|
bytes.Add(0);
|
|
continue;
|
|
}
|
|
var shr = instrs[i + 3];
|
|
if (shr.OpCode.Code != Code.Shr)
|
|
return false;
|
|
|
|
var convu1 = instrs[i + 4];
|
|
if (convu1.OpCode.Code != Code.Conv_U1)
|
|
return false;
|
|
|
|
int constant;
|
|
int index = i + 2;
|
|
if (!constantsReader.GetInt32(ref index, out constant))
|
|
return false;
|
|
|
|
bytes.Add(constant);
|
|
}
|
|
|
|
return false;
|
|
}
|
|
|
|
static MethodDef FindInt64Method(MethodDef method) {
|
|
foreach (var instr in method.Body.Instructions) {
|
|
if (instr.OpCode.Code != Code.Call)
|
|
continue;
|
|
var calledMethod = instr.Operand as MethodDef;
|
|
if (calledMethod == null)
|
|
continue;
|
|
if (!DotNetUtils.IsMethod(calledMethod, "System.Int64", "()"))
|
|
continue;
|
|
|
|
return calledMethod;
|
|
}
|
|
return null;
|
|
}
|
|
|
|
static TypeDef FindDataDecrypterType(MethodDef method) {
|
|
foreach (var instr in method.Body.Instructions) {
|
|
if (instr.OpCode.Code != Code.Call)
|
|
continue;
|
|
var calledMethod = instr.Operand as MethodDef;
|
|
if (calledMethod == null)
|
|
continue;
|
|
if (!DotNetUtils.IsMethod(calledMethod, "System.Byte[]", "(System.Byte[],System.Byte[])"))
|
|
continue;
|
|
|
|
return calledMethod.DeclaringType;
|
|
}
|
|
return null;
|
|
}
|
|
|
|
bool FindShorts() {
|
|
int index = 0;
|
|
if (!FindShort(ref index, ref s1))
|
|
return false;
|
|
if (!FindShort(ref index, ref s2))
|
|
return false;
|
|
if (!FindShort(ref index, ref s3))
|
|
return false;
|
|
|
|
return true;
|
|
}
|
|
|
|
bool FindShort(ref int index, ref short s) {
|
|
if (!FindCallReadInt16(ref index))
|
|
return false;
|
|
index++;
|
|
return stringMethodConsts.GetInt16(ref index, out s);
|
|
}
|
|
|
|
bool FindInts(int index) {
|
|
if (index < 0)
|
|
return false;
|
|
|
|
//i2 = 0;
|
|
var instrs = stringMethod.Body.Instructions;
|
|
|
|
var emu = new InstructionEmulator(stringMethod);
|
|
foreach (var kv in stringMethodConsts.Locals32)
|
|
emu.SetLocal(kv.Key, new Int32Value(kv.Value));
|
|
|
|
var fields = new Dictionary<FieldDef, int?>();
|
|
for (int i = index; i < instrs.Count - 2; i++) {
|
|
var instr = instrs[i];
|
|
|
|
FieldDef field;
|
|
switch (instr.OpCode.Code) {
|
|
case Code.Ldsfld:
|
|
field = instr.Operand as FieldDef;
|
|
if (field == null || field.DeclaringType != stringMethod.DeclaringType || field.FieldType.GetElementType() != ElementType.I4)
|
|
goto default;
|
|
fields[field] = null;
|
|
emu.Push(new Int32Value(i1));
|
|
break;
|
|
|
|
case Code.Stsfld:
|
|
field = instr.Operand as FieldDef;
|
|
if (field == null || field.DeclaringType != stringMethod.DeclaringType || field.FieldType.GetElementType() != ElementType.I4)
|
|
goto default;
|
|
if (fields.ContainsKey(field) && fields[field] == null)
|
|
goto default;
|
|
var val = emu.Pop() as Int32Value;
|
|
if (val == null || !val.AllBitsValid())
|
|
fields[field] = null;
|
|
else
|
|
fields[field] = val.Value;
|
|
break;
|
|
|
|
case Code.Call:
|
|
var method = instr.Operand as MethodDef;
|
|
if (!decrypterType.Detected || method != decrypterType.Int64Method)
|
|
goto done;
|
|
emu.Push(new Int64Value((long)decrypterType.GetMagic()));
|
|
break;
|
|
|
|
case Code.Newobj:
|
|
if (!EmulateDynocode(emu, ref i))
|
|
goto default;
|
|
break;
|
|
|
|
default:
|
|
if (instr.OpCode.FlowControl != FlowControl.Next)
|
|
goto done;
|
|
emu.Emulate(instr);
|
|
break;
|
|
}
|
|
}
|
|
done:
|
|
|
|
foreach (var val in fields.Values) {
|
|
if (val == null)
|
|
continue;
|
|
magic1 = /*i2 =*/ val.Value;
|
|
return true;
|
|
}
|
|
|
|
return false;
|
|
}
|
|
|
|
bool EmulateDynocode(InstructionEmulator emu, ref int index) {
|
|
if (isV51OrLater)
|
|
return EmulateDynocodeNew(emu, ref index);
|
|
return EmulateDynocodeOld(emu, ref index);
|
|
}
|
|
|
|
// <= 5.0
|
|
bool EmulateDynocodeOld(InstructionEmulator emu, ref int index) {
|
|
var instrs = stringMethod.Body.Instructions;
|
|
var instr = instrs[index];
|
|
|
|
var ctor = instr.Operand as MethodDef;
|
|
if (ctor == null || ctor.MethodSig.GetParamCount() != 1 || ctor.MethodSig.Params[0].ElementType != ElementType.I4)
|
|
return false;
|
|
|
|
if (index + 4 >= instrs.Count)
|
|
return false;
|
|
var ldloc = instrs[index + 3];
|
|
var stfld = instrs[index + 4];
|
|
if (!ldloc.IsLdloc() || stfld.OpCode.Code != Code.Stfld)
|
|
return false;
|
|
var enumerableField = stfld.Operand as FieldDef;
|
|
if (enumerableField == null)
|
|
return false;
|
|
|
|
var initValue = emu.GetLocal(ldloc.GetLocal(stringMethod.Body.Variables)) as Int32Value;
|
|
if (initValue == null || !initValue.AllBitsValid())
|
|
return false;
|
|
|
|
int leaveIndex = FindLeave(instrs, index);
|
|
if (leaveIndex < 0)
|
|
return false;
|
|
var afterLoop = instrs[leaveIndex].Operand as Instruction;
|
|
if (afterLoop == null)
|
|
return false;
|
|
int newIndex = instrs.IndexOf(afterLoop);
|
|
var loopLocal = GetDCLoopLocal(index, newIndex);
|
|
if (loopLocal == null)
|
|
return false;
|
|
var initValue2 = emu.GetLocal(loopLocal) as Int32Value;
|
|
if (initValue2 == null || !initValue2.AllBitsValid())
|
|
return false;
|
|
|
|
int loopStart = GetIndexOfCall(instrs, index, leaveIndex, "System.Int32", "()");
|
|
int loopEnd = GetIndexOfCall(instrs, loopStart, leaveIndex, "System.Boolean", "()");
|
|
if (loopStart < 0 || loopEnd < 0)
|
|
return false;
|
|
loopStart++;
|
|
loopEnd--;
|
|
|
|
dynocode.Initialize(module);
|
|
var ctorArg = emu.Pop() as Int32Value;
|
|
if (ctorArg == null || !ctorArg.AllBitsValid())
|
|
return false;
|
|
dynocode.CreateEnumerable(ctor, new object[] { ctorArg.Value });
|
|
dynocode.WriteEnumerableField(enumerableField.MDToken.ToUInt32(), initValue.Value);
|
|
dynocode.CreateEnumerator();
|
|
foreach (var val in dynocode) {
|
|
emu.Push(new Int32Value(val));
|
|
for (int i = loopStart; i < loopEnd; i++)
|
|
emu.Emulate(instrs[i]);
|
|
}
|
|
|
|
index = newIndex - 1;
|
|
return true;
|
|
}
|
|
|
|
// 5.1+
|
|
// the only changes are the indexes of ldloc and stfld
|
|
bool EmulateDynocodeNew(InstructionEmulator emu, ref int index) {
|
|
var instrs = stringMethod.Body.Instructions;
|
|
var instr = instrs[index];
|
|
|
|
var ctor = instr.Operand as MethodDef;
|
|
if (ctor == null || ctor.MethodSig.GetParamCount() != 1 || ctor.MethodSig.Params[0].ElementType != ElementType.I4)
|
|
return false;
|
|
|
|
if (index + 4 >= instrs.Count)
|
|
return false;
|
|
var ldloc = instrs[index + 2];
|
|
var stfld = instrs[index + 3];
|
|
if (!ldloc.IsLdloc() || stfld.OpCode.Code != Code.Stfld)
|
|
return false;
|
|
var enumerableField = stfld.Operand as FieldDef;
|
|
if (enumerableField == null)
|
|
return false;
|
|
|
|
var initValue = emu.GetLocal(ldloc.GetLocal(stringMethod.Body.Variables)) as Int32Value;
|
|
if (initValue == null || !initValue.AllBitsValid())
|
|
return false;
|
|
|
|
int leaveIndex = FindLeave(instrs, index);
|
|
if (leaveIndex < 0)
|
|
return false;
|
|
var afterLoop = instrs[leaveIndex].Operand as Instruction;
|
|
if (afterLoop == null)
|
|
return false;
|
|
int newIndex = instrs.IndexOf(afterLoop);
|
|
var loopLocal = GetDCLoopLocal(index, newIndex);
|
|
if (loopLocal == null)
|
|
return false;
|
|
var initValue2 = emu.GetLocal(loopLocal) as Int32Value;
|
|
if (initValue2 == null || !initValue2.AllBitsValid())
|
|
return false;
|
|
|
|
int loopStart = GetIndexOfCall(instrs, index, leaveIndex, "System.Int32", "()");
|
|
int loopEnd = GetIndexOfCall(instrs, loopStart, leaveIndex, "System.Boolean", "()");
|
|
if (loopStart < 0 || loopEnd < 0)
|
|
return false;
|
|
loopStart++;
|
|
loopEnd--;
|
|
|
|
dynocode.Initialize(module);
|
|
var ctorArg = emu.Pop() as Int32Value;
|
|
if (ctorArg == null || !ctorArg.AllBitsValid())
|
|
return false;
|
|
dynocode.CreateEnumerable(ctor, new object[] { ctorArg.Value });
|
|
dynocode.WriteEnumerableField(enumerableField.MDToken.ToUInt32(), initValue.Value);
|
|
dynocode.CreateEnumerator();
|
|
foreach (var val in dynocode) {
|
|
emu.Push(new Int32Value(val));
|
|
for (int i = loopStart; i < loopEnd; i++)
|
|
emu.Emulate(instrs[i]);
|
|
}
|
|
|
|
index = newIndex - 1;
|
|
return true;
|
|
}
|
|
|
|
static int GetIndexOfCall(IList<Instruction> instrs, int startIndex, int endIndex, string returnType, string parameters) {
|
|
if (startIndex < 0 || endIndex < 0)
|
|
return -1;
|
|
for (int i = startIndex; i < endIndex; i++) {
|
|
var instr = instrs[i];
|
|
if (instr.OpCode.Code != Code.Call && instr.OpCode.Code != Code.Callvirt)
|
|
continue;
|
|
var method = instr.Operand as IMethod;
|
|
if (!DotNetUtils.IsMethod(method, returnType, parameters))
|
|
continue;
|
|
|
|
return i;
|
|
}
|
|
return -1;
|
|
}
|
|
|
|
Local GetDCLoopLocal(int start, int end) {
|
|
var instrs = stringMethod.Body.Instructions;
|
|
for (int i = start; i < end - 1; i++) {
|
|
if (instrs[i].OpCode.Code != Code.Xor)
|
|
continue;
|
|
var stloc = instrs[i + 1];
|
|
if (!stloc.IsStloc())
|
|
continue;
|
|
return stloc.GetLocal(stringMethod.Body.Variables);
|
|
}
|
|
return null;
|
|
}
|
|
|
|
static int FindLeave(IList<Instruction> instrs, int index) {
|
|
for (int i = index; i < instrs.Count; i++) {
|
|
if (instrs[i].OpCode.Code == Code.Leave_S || instrs[i].OpCode.Code == Code.Leave)
|
|
return i;
|
|
}
|
|
return -1;
|
|
}
|
|
|
|
static int FindInitIntsIndex(MethodDef method, out bool initializedAll) {
|
|
initializedAll = false;
|
|
|
|
var instrs = method.Body.Instructions;
|
|
for (int i = 0; i < instrs.Count; i++) {
|
|
var ldnull = instrs[i];
|
|
if (ldnull.OpCode.Code != Code.Ldnull)
|
|
continue;
|
|
|
|
var stsfld = instrs[i + 1];
|
|
if (stsfld.OpCode.Code != Code.Stsfld)
|
|
continue;
|
|
|
|
var storeField = stsfld.Operand as FieldDef;
|
|
if (storeField == null || storeField.FieldType.FullName != "System.Byte[]")
|
|
continue;
|
|
|
|
var instr = instrs[i + 2];
|
|
if (instr.OpCode.Code == Code.Ldsfld) {
|
|
var loadField = instr.Operand as FieldDef;
|
|
if (loadField == null || loadField.FieldType.GetElementType() != ElementType.I4)
|
|
continue;
|
|
}
|
|
else if (instr.IsLdcI4()) {
|
|
initializedAll = true;
|
|
}
|
|
else
|
|
continue;
|
|
|
|
return i;
|
|
}
|
|
|
|
return -1;
|
|
}
|
|
|
|
bool FindIntsCctor(MethodDef cctor) {
|
|
int index = 0;
|
|
if (!FindCallGetFrame(cctor, ref index))
|
|
return FindIntsCctor2(cctor);
|
|
|
|
int tmp1, tmp2, tmp3 = 0;
|
|
var constantsReader = new EfConstantsReader(cctor);
|
|
if (!constantsReader.GetNextInt32(ref index, out tmp1))
|
|
return false;
|
|
if (tmp1 == 0 && !constantsReader.GetNextInt32(ref index, out tmp1))
|
|
return false;
|
|
if (!constantsReader.GetNextInt32(ref index, out tmp2))
|
|
return false;
|
|
if (tmp2 == 0 && !constantsReader.GetNextInt32(ref index, out tmp2))
|
|
return false;
|
|
|
|
index = 0;
|
|
var instrs = cctor.Body.Instructions;
|
|
while (index < instrs.Count) {
|
|
int tmp4;
|
|
if (!constantsReader.GetNextInt32(ref index, out tmp4))
|
|
break;
|
|
if (index < instrs.Count && instrs[index].IsLdloc())
|
|
tmp3 = tmp4;
|
|
}
|
|
|
|
i1 = tmp1 ^ tmp2 ^ tmp3;
|
|
return true;
|
|
}
|
|
|
|
// Compact Framework doesn't have StackFrame
|
|
bool FindIntsCctor2(MethodDef cctor) {
|
|
int index = 0;
|
|
var instrs = cctor.Body.Instructions;
|
|
var constantsReader = new EfConstantsReader(cctor);
|
|
while (index >= 0) {
|
|
int val;
|
|
if (!constantsReader.GetNextInt32(ref index, out val))
|
|
break;
|
|
if (index < instrs.Count && instrs[index].OpCode.Code == Code.Add) {
|
|
i1 = val;
|
|
return true;
|
|
}
|
|
}
|
|
|
|
return false;
|
|
}
|
|
|
|
bool FindInt3() {
|
|
if (!isV32OrLater)
|
|
return FindInt3Old();
|
|
return FindInt3New();
|
|
}
|
|
|
|
// <= 3.1
|
|
bool FindInt3Old() {
|
|
var instrs = stringMethod.Body.Instructions;
|
|
for (int i = 0; i < instrs.Count - 4; i++) {
|
|
var ldarg0 = instrs[i];
|
|
if (ldarg0.OpCode.Code != Code.Ldarg_0)
|
|
continue;
|
|
|
|
var ldci4 = instrs[i + 1];
|
|
if (!ldci4.IsLdcI4())
|
|
continue;
|
|
|
|
int index = i + 1;
|
|
int value;
|
|
if (!stringMethodConsts.GetInt32(ref index, out value))
|
|
continue;
|
|
if (index >= instrs.Count)
|
|
continue;
|
|
|
|
if (instrs[index].OpCode.Code != Code.Xor)
|
|
continue;
|
|
|
|
i3 = value;
|
|
return true;
|
|
}
|
|
|
|
return false;
|
|
}
|
|
|
|
// 3.2+
|
|
bool FindInt3New() {
|
|
var instrs = stringMethod.Body.Instructions;
|
|
for (int i = 0; i < instrs.Count; i++) {
|
|
int index = i;
|
|
|
|
var ldarg0 = instrs[index++];
|
|
if (ldarg0.OpCode.Code != Code.Ldarg_0)
|
|
continue;
|
|
|
|
int value;
|
|
if (!stringMethodConsts.GetInt32(ref index, out value))
|
|
continue;
|
|
|
|
if (index + 3 >= instrs.Count)
|
|
break;
|
|
|
|
if (instrs[index++].OpCode.Code != Code.Xor)
|
|
continue;
|
|
|
|
if (!instrs[index++].IsLdloc())
|
|
continue;
|
|
|
|
if (instrs[index++].OpCode.Code != Code.Xor)
|
|
continue;
|
|
|
|
i3 = value;
|
|
if (!FindInt6(index++))
|
|
return false;
|
|
return true;
|
|
}
|
|
|
|
return false;
|
|
}
|
|
|
|
// v3.3.134+
|
|
bool FindInt6(int index) {
|
|
index = GetNextLdci4InSameBlock(index);
|
|
if (index < 0)
|
|
return true;
|
|
|
|
return stringMethodConsts.GetNextInt32(ref index, out i6);
|
|
}
|
|
|
|
bool FindInt4() {
|
|
int index = 0;
|
|
if (!FindCallReadInt32(ref index))
|
|
return false;
|
|
if (!stringMethodConsts.GetNextInt32(ref index, out i4))
|
|
return false;
|
|
|
|
return true;
|
|
}
|
|
|
|
int GetNextLdci4InSameBlock(int index) {
|
|
var instrs = stringMethod.Body.Instructions;
|
|
for (int i = index; i < instrs.Count; i++) {
|
|
var instr = instrs[i];
|
|
if (instr.OpCode.FlowControl != FlowControl.Next)
|
|
return -1;
|
|
if (stringMethodConsts.IsLoadConstantInt32(instr))
|
|
return i;
|
|
}
|
|
|
|
return -1;
|
|
}
|
|
|
|
bool FindInt5() {
|
|
int index = -1;
|
|
while (true) {
|
|
index++;
|
|
if (!FindCallReadBytes(ref index))
|
|
return false;
|
|
if (index <= 0)
|
|
continue;
|
|
var ldci4 = stringMethod.Body.Instructions[index - 1];
|
|
if (!ldci4.IsLdcI4())
|
|
continue;
|
|
if (ldci4.GetLdcI4Value() != 4)
|
|
continue;
|
|
if (!stringMethodConsts.GetNextInt32(ref index, out i5))
|
|
return false;
|
|
|
|
return true;
|
|
}
|
|
}
|
|
|
|
static bool CallsGetPublicKeyToken(MethodDef method) {
|
|
int index = 0;
|
|
return FindCall(method, ref index, "System.Byte[] System.Reflection.AssemblyName::GetPublicKeyToken()");
|
|
}
|
|
|
|
bool FindCallReadInt16(ref int index) {
|
|
return FindCall(stringMethod, ref index, streamHelperType == null ? "System.Int16 System.IO.BinaryReader::ReadInt16()" : streamHelperType.readInt16Method.FullName);
|
|
}
|
|
|
|
bool FindCallReadInt32(ref int index) {
|
|
return FindCall(stringMethod, ref index, streamHelperType == null ? "System.Int32 System.IO.BinaryReader::ReadInt32()" : streamHelperType.readInt32Method.FullName);
|
|
}
|
|
|
|
bool FindCallReadBytes(ref int index) {
|
|
return FindCall(stringMethod, ref index, streamHelperType == null ? "System.Byte[] System.IO.BinaryReader::ReadBytes(System.Int32)" : streamHelperType.readBytesMethod.FullName);
|
|
}
|
|
|
|
static bool FindCallGetFrame(MethodDef method, ref int index) {
|
|
return FindCall(method, ref index, "System.Diagnostics.StackFrame System.Diagnostics.StackTrace::GetFrame(System.Int32)");
|
|
}
|
|
|
|
static bool FindCall(MethodDef method, ref int index, string methodFullName) {
|
|
for (; index < method.Body.Instructions.Count; index++) {
|
|
if (!FindCallvirt(method, ref index))
|
|
return false;
|
|
|
|
var calledMethod = method.Body.Instructions[index].Operand as IMethod;
|
|
if (calledMethod == null)
|
|
continue;
|
|
if (calledMethod.ToString() != methodFullName)
|
|
continue;
|
|
|
|
return true;
|
|
}
|
|
return false;
|
|
}
|
|
|
|
static bool FindCallvirt(MethodDef method, ref int index) {
|
|
var instrs = method.Body.Instructions;
|
|
for (; index < instrs.Count; index++) {
|
|
var instr = instrs[index];
|
|
if (instr.OpCode.Code != Code.Callvirt)
|
|
continue;
|
|
|
|
return true;
|
|
}
|
|
|
|
return false;
|
|
}
|
|
|
|
public void Dispose() {
|
|
CloseServer();
|
|
}
|
|
|
|
public void CloseServer() {
|
|
if (dynocode != null)
|
|
dynocode.Dispose();
|
|
dynocode = null;
|
|
}
|
|
}
|
|
}
|