/*
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 .
*/
using System;
using System.Collections.Generic;
using System.IO;
using System.Text;
using dnlib.DotNet;
using dnlib.IO;
using dnlib.PE;
using de4dot.blocks;
namespace de4dot.code.deobfuscators.MaxtoCode {
// Decrypts methods, resources and strings (#US heap)
class MethodsDecrypter {
ModuleDef module;
DecrypterInfo decrypterInfo;
class MethodInfos {
ModuleDef module;
MainType mainType;
MyPEImage peImage;
PeHeader peHeader;
McKey mcKey;
uint structSize;
uint methodInfosOffset;
uint encryptedDataOffset;
uint xorKey;
Dictionary infos = new Dictionary();
List decrypters = new List();
const int ENCRYPTED_DATA_INFO_SIZE = 0x13;
delegate byte[] DecryptFunc(byte[] encrypted);
public class DecryptedMethodInfo {
public uint bodyRva;
public byte[] body;
public DecryptedMethodInfo(uint bodyRva, byte[] body) {
this.bodyRva = bodyRva;
this.body = body;
}
}
public MethodInfos(ModuleDef module, MainType mainType, MyPEImage peImage, PeHeader peHeader, McKey mcKey) {
this.module = module;
this.mainType = mainType;
this.peImage = peImage;
this.peHeader = peHeader;
this.mcKey = mcKey;
structSize = GetStructSize(mcKey);
uint methodInfosRva = peHeader.GetRva(0x0FF8, mcKey.ReadUInt32(0x005A));
uint encryptedDataRva = peHeader.GetRva(0x0FF0, mcKey.ReadUInt32(0x0046));
methodInfosOffset = peImage.RvaToOffset(methodInfosRva);
encryptedDataOffset = peImage.RvaToOffset(encryptedDataRva);
}
static uint GetStructSize(McKey mcKey) {
uint magicLo = mcKey.ReadUInt32(0x8C0);
uint magicHi = mcKey.ReadUInt32(0x8C4);
foreach (var info in EncryptionInfos.McKey8C0h) {
if (magicLo == info.MagicLo && magicHi == info.MagicHi)
return 0xC + 6 * ENCRYPTED_DATA_INFO_SIZE;
}
return 0xC + 3 * ENCRYPTED_DATA_INFO_SIZE;
}
EncryptionVersion GetVersion() {
if (peHeader.EncryptionVersion != EncryptionVersion.Unknown)
return peHeader.EncryptionVersion;
uint m2lo = mcKey.ReadUInt32(0x8C0);
uint m2hi = mcKey.ReadUInt32(0x8C4);
foreach (var info in EncryptionInfos.McKey8C0h) {
if (info.MagicLo == m2lo && info.MagicHi == m2hi)
return info.Version;
}
Logger.w("Could not detect MC version. Magic2: {0:X8} {1:X8}", m2lo, m2hi);
return EncryptionVersion.Unknown;
}
public DecryptedMethodInfo Lookup(uint bodyRva) {
DecryptedMethodInfo info;
infos.TryGetValue(bodyRva, out info);
return info;
}
byte ReadByte(uint offset) {
return peImage.OffsetReadByte(methodInfosOffset + offset);
}
short ReadInt16(uint offset) {
return (short)peImage.OffsetReadUInt16(methodInfosOffset + offset);
}
uint ReadUInt32(uint offset) {
return peImage.OffsetReadUInt32(methodInfosOffset + offset);
}
int ReadInt32(uint offset) {
return (int)ReadUInt32(offset);
}
short ReadEncryptedInt16(uint offset) {
return (short)(ReadInt16(offset) ^ xorKey);
}
int ReadEncryptedInt32(uint offset) {
return (int)ReadEncryptedUInt32(offset);
}
uint ReadEncryptedUInt32(uint offset) {
return ReadUInt32(offset) ^ xorKey;
}
interface IDecrypter {
byte[] Decrypt(int type, byte[] encrypted);
bool HasTimeStamp(uint timeStamp);
}
class Decrypter : IDecrypter {
DecryptFunc[] decrypterHandlers;
uint[] timeStamps;
public Decrypter(DecryptFunc[] decrypterHandlers)
: this(decrypterHandlers, null) {
}
public Decrypter(DecryptFunc[] decrypterHandlers, uint[] timeStamps) {
this.decrypterHandlers = decrypterHandlers;
this.timeStamps = timeStamps ?? new uint[0];
}
public byte[] Decrypt(int type, byte[] encrypted) {
if (1 <= type && type <= decrypterHandlers.Length)
return decrypterHandlers[type - 1](encrypted);
throw new ApplicationException(string.Format("Invalid encryption type: {0:X2}", type));
}
public bool HasTimeStamp(uint timeStamp) {
foreach (var ts in timeStamps) {
if (timeStamp == ts)
return true;
}
return false;
}
}
void InitializeDecrypter() {
switch (GetVersion()) {
case EncryptionVersion.V1:
decrypters.Add(new Decrypter(new DecryptFunc[] { Decrypt1_v1, Decrypt4_v1, Decrypt2_v1, Decrypt3_v1, Decrypt5, Decrypt6, Decrypt7 }, new uint[] { 0x462FA2D2 }));
decrypters.Add(new Decrypter(new DecryptFunc[] { Decrypt4_v1, Decrypt1_v1, Decrypt2_v1, Decrypt3_v1, Decrypt5, Decrypt6, Decrypt7 }, new uint[] { 0x471299D3 }));
break;
case EncryptionVersion.V2: decrypters.Add(new Decrypter(new DecryptFunc[] { Decrypt3_v1, Decrypt2_v1, Decrypt1_v1, Decrypt4_v1, Decrypt5, Decrypt6, Decrypt7 }, new uint[] { 0x482384FB, 0x4A5EEC64, 0x4BD6F703, 0x4C6220EC, 0x4C622357, 0x4C6E4605, 0x4D0E220D, 0x4DC2FC75, 0x4DC2FE0C, 0x4DFA3D5D })); break;
case EncryptionVersion.V3: decrypters.Add(new Decrypter(new DecryptFunc[] { Decrypt1_v1, Decrypt2_v1, Decrypt3_v1, Decrypt4_v1, Decrypt5, Decrypt6, Decrypt7 }, new uint[] { 0x4ECF2195, 0x4ED76740, 0x4EE1FAD1 })); break;
case EncryptionVersion.V4: decrypters.Add(new Decrypter(new DecryptFunc[] { Decrypt2_v1, Decrypt1_v1, Decrypt3_v1, Decrypt4_v1, Decrypt5, Decrypt6, Decrypt7 }, new uint[] { 0x4F832868, 0x4F8C86BE, 0x4F9447DB, 0x4FDEF2FF })); break;
case EncryptionVersion.V5:
decrypters.Add(new Decrypter(new DecryptFunc[] { Decrypt4_v1, Decrypt2_v1, Decrypt3_v1, Decrypt1_v1, Decrypt5, Decrypt6, Decrypt7 }, new uint[] { 0x4F8E262C, 0x4F966B0B, 0x4FAB3CCF }));
decrypters.Add(new Decrypter(new DecryptFunc[] { Decrypt4_v2, Decrypt2_v2, Decrypt3_v2, Decrypt1_v2, Decrypt6, Decrypt7, Decrypt5 }, new uint[] { 0x4FC7459E, 0x4FCEBD7B }));
decrypters.Add(new Decrypter(new DecryptFunc[] { Decrypt4_v3, Decrypt2_v3, Decrypt3_v3, Decrypt1_v3, Decrypt6, Decrypt7, Decrypt5 }, new uint[] { 0x4FBE81DE }));
break;
case EncryptionVersion.V6: decrypters.Add(new Decrypter(new DecryptFunc[] { Decrypt4_v4, Decrypt2_v4, Decrypt3_v4, Decrypt1_v4, Decrypt6, Decrypt7, Decrypt5 }, new uint[] { 0x50A0963C })); break;
case EncryptionVersion.V7: decrypters.Add(new Decrypter(new DecryptFunc[] { Decrypt4_v5, Decrypt2_v5, Decrypt3_v5, Decrypt1_v5, Decrypt6, Decrypt8_v5, Decrypt9_v5, Decrypt7, Decrypt5 }, new uint[] { 0x50D367A5 })); break;
case EncryptionVersion.V8:
decrypters.Add(new Decrypter(new DecryptFunc[] { Decrypt4_v6, Decrypt2_v2, Decrypt3_v6, Decrypt1_v6, Decrypt6, Decrypt8_v6, Decrypt9_v6, Decrypt7, Decrypt10, Decrypt5 }, new uint[] { 0x5166DB4F, 0x51927495 }));
decrypters.Add(new Decrypter(new DecryptFunc[] { Decrypt4_v7, Decrypt2_v2, Decrypt3_v6, Decrypt1_v7, Decrypt6, Decrypt8_v7, Decrypt9_v7, Decrypt7, Decrypt5 }, new uint[] { 0x51413D68 }));
decrypters.Add(new Decrypter(new DecryptFunc[] { Decrypt4_v7, Decrypt2_v2, Decrypt3_v6, Decrypt1_v7, Decrypt6, Decrypt8_v8, Decrypt9_v8, Decrypt7, Decrypt5 }, new uint[] { 0x513D7124, 0x51413BD8 }));
decrypters.Add(new Decrypter(new DecryptFunc[] { Decrypt4_v5, Decrypt2_v2, Decrypt3_v6, Decrypt1_v9, Decrypt6, Decrypt8_v8, Decrypt9_v9, Decrypt7, Decrypt5 }, new uint[] { 0x513D4492, 0x5113E277 }));
decrypters.Add(new Decrypter(new DecryptFunc[] { Decrypt3_v6, Decrypt2_v2, Decrypt4_v8, Decrypt1_v10, Decrypt8_v9, Decrypt9_v10, Decrypt6, Decrypt7, Decrypt5 }, new uint[] { 0x526BDD12 }));
decrypters.Add(new Decrypter(new DecryptFunc[] { Decrypt1_v10, Decrypt4_v8, Decrypt2_v2, Decrypt3_v6, Decrypt6, Decrypt8_v9, Decrypt9_v10, Decrypt7, Decrypt5 }, new uint[] { 0x526BC020 }));
decrypters.Add(new Decrypter(new DecryptFunc[] { Decrypt3_v7, Decrypt2_v6, Decrypt4_v9, Decrypt1_v11, Decrypt8_v10, Decrypt11_v1, Decrypt6, Decrypt7, Decrypt5 }, new uint[] { 0x5296E242, 0x52B3043C }));
decrypters.Add(new Decrypter(new DecryptFunc[] { Decrypt4_v10, Decrypt1_v12, Decrypt3_v8, Decrypt2_v7, Decrypt6, Decrypt8_v11, Decrypt9_v11, Decrypt7, Decrypt5 }, new uint[] { 0x531729C4 }));
decrypters.Add(new Decrypter(new DecryptFunc[] { Decrypt1_v13, Decrypt4_v11, Decrypt2_v8, Decrypt3_v9, Decrypt6, Decrypt8_v11, Decrypt9_v12, Decrypt7, Decrypt5 }, new uint[] { 0x52B2B2A3 }));
decrypters.Add(new Decrypter(new DecryptFunc[] { Decrypt2_v9, Decrypt3_v10, Decrypt1_v10, Decrypt4_v12, Decrypt8_v12, Decrypt9_v13, Decrypt6, Decrypt7, Decrypt5 }, new uint[] { 0x53172907 }));
break;
case EncryptionVersion.Unknown:
default:
throw new ApplicationException("Unknown MC version");
}
}
public void InitializeInfos() {
InitializeDecrypter();
if (!InitializeInfos2())
throw new ApplicationException("Could not decrypt methods");
}
uint GetRuntimeTimeStamp() {
string path = module.Location;
if (string.IsNullOrEmpty(path))
return 0;
try {
var rtNames = new List();
foreach (var rtModRef in mainType.RuntimeModuleRefs) {
string dllName = rtModRef.Name;
if (!dllName.ToUpperInvariant().EndsWith(".DLL"))
dllName += ".dll";
rtNames.Add(dllName);
}
if (rtNames.Count == 0)
return 0;
for (var di = new DirectoryInfo(Path.GetDirectoryName(path)); di != null; di = di.Parent) {
foreach (var dllName in rtNames) {
try {
using (var peImage = new PEImage(Path.Combine(di.FullName, dllName))) {
if (peImage.ImageNTHeaders.FileHeader.Machine == Machine.I386)
return peImage.ImageNTHeaders.FileHeader.TimeDateStamp;
}
}
catch {
}
}
}
}
catch {
}
return 0;
}
bool InitializeInfos2() {
uint rtTimeStamp = GetRuntimeTimeStamp();
if (rtTimeStamp != 0) {
var decrypter = GetCorrectDecrypter(rtTimeStamp);
if (decrypter != null) {
try {
if (InitializeInfos2(decrypter))
return true;
}
catch {
}
}
}
Dictionary savedInfos = null;
foreach (var decrypter in decrypters) {
try {
if (InitializeInfos2(decrypter)) {
if (savedInfos != null) {
Logger.w("Decryption probably failed. Make sure the correct MaxtoCode runtime file is present.");
break;
}
savedInfos = infos;
infos = new Dictionary();
}
}
catch {
}
}
if (savedInfos == null)
return false;
infos = savedInfos;
return true;
}
IDecrypter GetCorrectDecrypter(uint timeStamp) {
foreach (var decrypter in decrypters) {
if (decrypter.HasTimeStamp(timeStamp))
return decrypter;
}
return null;
}
bool InitializeInfos2(IDecrypter decrypter) {
int numMethods = ReadInt32(0) ^ ReadInt32(4);
if (numMethods < 0)
throw new ApplicationException("Invalid number of encrypted methods");
xorKey = (uint)numMethods;
int numEncryptedDataInfos = ((int)structSize - 0xC) / ENCRYPTED_DATA_INFO_SIZE;
var encryptedDataInfos = new byte[numEncryptedDataInfos][];
uint offset = 8;
infos.Clear();
for (int i = 0; i < numMethods; i++, offset += structSize) {
uint methodBodyRva = ReadEncryptedUInt32(offset);
uint totalSize = ReadEncryptedUInt32(offset + 4);
uint methodInstructionRva = ReadEncryptedUInt32(offset + 8);
// Read the method body header and method body (instrs + exception handlers).
// The method body header is always in the first one. The instrs + ex handlers
// are always in the last 4, and evenly divided (each byte[] is totalLen / 4).
// The 2nd one is for the exceptions (or padding), but it may be null.
uint offset2 = offset + 0xC;
int exOffset = 0;
for (int j = 0; j < encryptedDataInfos.Length; j++, offset2 += ENCRYPTED_DATA_INFO_SIZE) {
// readByte(offset2); <-- index
int encryptionType = ReadEncryptedInt16(offset2 + 1);
uint dataOffset = ReadEncryptedUInt32(offset2 + 3);
uint encryptedSize = ReadEncryptedUInt32(offset2 + 7);
uint realSize = ReadEncryptedUInt32(offset2 + 11);
if (j >= 3 && dataOffset == xorKey && encryptedSize == xorKey) {
encryptedDataInfos[j] = null;
continue;
}
if (j == 1)
exOffset = ReadEncryptedInt32(offset2 + 15);
if (j == 1 && exOffset == 0)
encryptedDataInfos[j] = null;
else
encryptedDataInfos[j] = Decrypt(decrypter, encryptionType, dataOffset, encryptedSize, realSize);
}
var decryptedData = new byte[totalSize];
int copyOffset = 0;
copyOffset = CopyData(decryptedData, encryptedDataInfos[0], copyOffset);
for (int j = 2; j < encryptedDataInfos.Length; j++)
copyOffset = CopyData(decryptedData, encryptedDataInfos[j], copyOffset);
CopyData(decryptedData, encryptedDataInfos[1], exOffset); // Exceptions or padding
if (!MethodBodyParser.Verify(decryptedData))
throw new InvalidMethodBody();
var info = new DecryptedMethodInfo(methodBodyRva, decryptedData);
infos[info.bodyRva] = info;
}
return true;
}
static int CopyData(byte[] dest, byte[] source, int offset) {
if (source == null)
return offset;
Array.Copy(source, 0, dest, offset, source.Length);
return offset + source.Length;
}
byte[] ReadData(uint offset, int size) {
return peImage.OffsetReadBytes(encryptedDataOffset + offset, size);
}
byte[] Decrypt(IDecrypter decrypter, int type, uint dataOffset, uint encryptedSize, uint realSize) {
if (realSize == 0)
return null;
if (realSize > encryptedSize)
throw new ApplicationException("Invalid realSize");
var encrypted = ReadData(dataOffset, (int)encryptedSize);
var decrypted = decrypter.Decrypt(type, encrypted);
if (realSize > decrypted.Length)
throw new ApplicationException("Invalid decrypted length");
Array.Resize(ref decrypted, (int)realSize);
return decrypted;
}
byte[] Decrypt1_v1(byte[] encrypted) {
return Decrypt1(encrypted, 0, 0, 0x2000);
}
byte[] Decrypt1_v2(byte[] encrypted) {
return Decrypt1(encrypted, 6, 6, 0x500);
}
byte[] Decrypt1_v3(byte[] encrypted) {
return Decrypt1(encrypted, 6, 0, 0x1000);
}
byte[] Decrypt1_v4(byte[] encrypted) {
return Decrypt1(encrypted, 5, 5, 0x500);
}
byte[] Decrypt1_v5(byte[] encrypted) {
return Decrypt1(encrypted, 9, 9, 0x500);
}
byte[] Decrypt1_v6(byte[] encrypted) {
return Decrypt1(encrypted, 0x27, 0x27, 0x100);
}
byte[] Decrypt1_v7(byte[] encrypted) {
return Decrypt1(encrypted, 0x1D, 0x1D, 0x400);
}
byte[] Decrypt1_v9(byte[] encrypted) {
return Decrypt1(encrypted, 9, 0x13, 0x400);
}
byte[] Decrypt1_v10(byte[] encrypted) {
return Decrypt1(encrypted, 0x11, 0x11, 0x400);
}
byte[] Decrypt1_v11(byte[] encrypted) {
return Decrypt1(encrypted, 0x13, 0x13, 0x400);
}
byte[] Decrypt1_v12(byte[] encrypted) {
return Decrypt1(encrypted, 0x12, 0x12, 0x200);
}
byte[] Decrypt1_v13(byte[] encrypted) {
return Decrypt1(encrypted, 0x11, 0x11, 0x200);
}
byte[] Decrypt1(byte[] encrypted, int keyStart, int keyReset, int keyEnd) {
var decrypted = new byte[encrypted.Length];
for (int i = 0, ki = keyStart; i < decrypted.Length; i++) {
decrypted[i] = (byte)(encrypted[i] ^ mcKey.ReadByte(ki));
if (++ki == keyEnd)
ki = keyReset;
}
return decrypted;
}
byte[] Decrypt2_v1(byte[] encrypted) {
return Decrypt2(encrypted, 0x00FA);
}
byte[] Decrypt2_v2(byte[] encrypted) {
return Decrypt2(encrypted, 0x00FA + 9);
}
byte[] Decrypt2_v3(byte[] encrypted) {
return Decrypt2(encrypted, 0x00FA + 0x24);
}
byte[] Decrypt2_v4(byte[] encrypted) {
return Decrypt2(encrypted, 0x00FA + 7);
}
byte[] Decrypt2_v5(byte[] encrypted) {
return Decrypt2(encrypted, 0x00FA + 0x63);
}
byte[] Decrypt2_v6(byte[] encrypted) {
return Decrypt2(encrypted, 0x00FA + 0x0B);
}
byte[] Decrypt2_v7(byte[] encrypted) {
return Decrypt2(encrypted, 0x00FA + 0x0E);
}
byte[] Decrypt2_v8(byte[] encrypted) {
return Decrypt2(encrypted, 0x00FA + 0x0D);
}
byte[] Decrypt2_v9(byte[] encrypted) {
return Decrypt2(encrypted, 0x00FA + 0x0C);
}
byte[] Decrypt2(byte[] encrypted, int offset) {
if ((encrypted.Length & 7) != 0)
throw new ApplicationException("Invalid encryption #2 length");
uint key4 = mcKey.ReadUInt32(offset + 4 * 4);
uint key5 = mcKey.ReadUInt32(offset + 5 * 4);
byte[] decrypted = new byte[encrypted.Length & ~7];
var writer = new BinaryWriter(new MemoryStream(decrypted));
int loopCount = encrypted.Length / 8;
for (int i = 0; i < loopCount; i++) {
uint val0 = BitConverter.ToUInt32(encrypted, i * 8);
uint val1 = BitConverter.ToUInt32(encrypted, i * 8 + 4);
uint x = (val1 >> 26) + (val0 << 6);
uint y = (val0 >> 26) + (val1 << 6);
writer.Write(x ^ key4);
writer.Write(y ^ key5);
}
return decrypted;
}
byte[] Decrypt3_v1(byte[] encrypted) {
return Decrypt3(encrypted, 0x015E);
}
byte[] Decrypt3_v2(byte[] encrypted) {
return Decrypt3(encrypted, 0x015E + 0xE5);
}
byte[] Decrypt3_v3(byte[] encrypted) {
return Decrypt3(encrypted, 0x015E + 0x28);
}
byte[] Decrypt3_v4(byte[] encrypted) {
return Decrypt3(encrypted, 0x015E + 8);
}
byte[] Decrypt3_v5(byte[] encrypted) {
return Decrypt3(encrypted, 0x015E + 7);
}
byte[] Decrypt3_v6(byte[] encrypted) {
return Decrypt3(encrypted, 0x015E + 0x7F);
}
byte[] Decrypt3_v7(byte[] encrypted) {
return Decrypt3(encrypted, 0x015E + 0x0D);
}
byte[] Decrypt3_v8(byte[] encrypted) {
return Decrypt3(encrypted, 0x015E + 0x0F);
}
byte[] Decrypt3_v9(byte[] encrypted) {
return Decrypt3(encrypted, 0x015E + 0x12);
}
byte[] Decrypt3_v10(byte[] encrypted) {
return Decrypt3(encrypted, 0x015E + 0x0E);
}
static readonly byte[] decrypt3Shifts = new byte[16] { 5, 11, 14, 21, 6, 20, 17, 29, 4, 10, 3, 2, 7, 1, 26, 18 };
byte[] Decrypt3(byte[] encrypted, int offset) {
if ((encrypted.Length & 7) != 0)
throw new ApplicationException("Invalid encryption #3 length");
uint key0 = mcKey.ReadUInt32(offset + 0 * 4);
uint key3 = mcKey.ReadUInt32(offset + 3 * 4);
byte[] decrypted = new byte[encrypted.Length & ~7];
var writer = new BinaryWriter(new MemoryStream(decrypted));
int loopCount = encrypted.Length / 8;
for (int i = 0; i < loopCount; i++) {
uint x = BitConverter.ToUInt32(encrypted, i * 8);
uint y = BitConverter.ToUInt32(encrypted, i * 8 + 4);
foreach (var shift in decrypt3Shifts) {
int shift1 = 32 - shift;
uint x1 = (y >> shift1) + (x << shift);
uint y1 = (x >> shift1) + (y << shift);
x = x1;
y = y1;
}
writer.Write(x ^ key0);
writer.Write(y ^ key3);
}
return decrypted;
}
byte[] Decrypt4_v1(byte[] encrypted) {
return Decrypt4(encrypted, 0, 0, 0x2000);
}
byte[] Decrypt4_v2(byte[] encrypted) {
return Decrypt4(encrypted, 0x14, 0x14, 0x1000);
}
byte[] Decrypt4_v3(byte[] encrypted) {
return Decrypt4(encrypted, 5, 0, 0x2000);
}
byte[] Decrypt4_v4(byte[] encrypted) {
return Decrypt4(encrypted, 0x0B, 0x0B, 0x1000);
}
byte[] Decrypt4_v5(byte[] encrypted) {
return Decrypt4(encrypted, 0x15, 0x15, 0x100);
}
byte[] Decrypt4_v6(byte[] encrypted) {
return Decrypt4(encrypted, 0x63, 0x63, 0x150);
}
byte[] Decrypt4_v7(byte[] encrypted) {
return Decrypt4(encrypted, 0x0B, 0x0B, 0x100);
}
byte[] Decrypt4_v8(byte[] encrypted) {
return Decrypt4(encrypted, 9, 9, 0x100);
}
byte[] Decrypt4_v9(byte[] encrypted) {
return Decrypt4(encrypted, 0x0B, 0x0B, 0x150);
}
byte[] Decrypt4_v10(byte[] encrypted) {
return Decrypt4(encrypted, 0x10, 0x10, 0x120);
}
byte[] Decrypt4_v11(byte[] encrypted) {
return Decrypt4(encrypted, 0x0F, 0x0E, 0x120);
}
byte[] Decrypt4_v12(byte[] encrypted) {
return Decrypt4(encrypted, 0x0C, 0x0C, 0x150);
}
byte[] Decrypt4(byte[] encrypted, int keyStart, int keyReset, int keyEnd) {
var decrypted = new byte[encrypted.Length / 3 * 2 + 1];
int count = encrypted.Length / 3;
int i = 0, ki = keyStart, j = 0;
while (count-- > 0) {
byte k1 = mcKey.ReadByte(ki + 1);
byte k2 = mcKey.ReadByte(ki + 2);
byte k3 = mcKey.ReadByte(ki + 3);
decrypted[j++] = (byte)(((encrypted[i + 1] ^ k2) >> 4) | ((encrypted[i] ^ k1) & 0xF0));
decrypted[j++] = (byte)(((encrypted[i + 1] ^ k2) << 4) | ((encrypted[i + 2] ^ k3) & 0x0F));
i += 3;
ki += 4;
if (ki >= keyEnd)
ki = keyReset;
}
if ((encrypted.Length % 3) != 0)
decrypted[j] = (byte)(encrypted[i] ^ mcKey.ReadByte(ki));
return decrypted;
}
byte[] Decrypt5(byte[] encrypted) {
return CryptDecrypter.Decrypt(mcKey.ReadBytes(0x0032, 15), encrypted);
}
byte[] Decrypt6(byte[] encrypted) {
return Decrypter6.Decrypt(mcKey.ReadBytes(0x0096, 32), encrypted);
}
byte[] Decrypt7(byte[] encrypted) {
var decrypted = (byte[])encrypted.Clone();
new Blowfish(GetBlowfishKey()).Decrypt_LE(decrypted);
return decrypted;
}
byte[] Decrypt8_v5(byte[] encrypted) {
return Decrypt8(encrypted, 7, 7, 0x600);
}
byte[] Decrypt8_v6(byte[] encrypted) {
return Decrypt8(encrypted, 0x1B, 0x1B, 0x100);
}
byte[] Decrypt8_v7(byte[] encrypted) {
return Decrypt8(encrypted, 0x0D, 0x0D, 0x600);
}
byte[] Decrypt8_v8(byte[] encrypted) {
return Decrypt8(encrypted, 0x11, 0x11, 0x600);
}
byte[] Decrypt8_v9(byte[] encrypted) {
return Decrypt8(encrypted, 0xA, 0xA, 0x600);
}
byte[] Decrypt8_v10(byte[] encrypted) {
return Decrypt8(encrypted, 0x14, 0x14, 0x600);
}
byte[] Decrypt8_v11(byte[] encrypted) {
return Decrypt8(encrypted, 0x19, 0x19, 0x500);
}
byte[] Decrypt8_v12(byte[] encrypted) {
return Decrypt8(encrypted, 0x14, 0x14, 0x600);
}
byte[] Decrypt8(byte[] encrypted, int keyStart, int keyReset, int keyEnd) {
var decrypted = new byte[encrypted.Length];
int ki = keyStart;
for (int i = 0; i < encrypted.Length; i++) {
int b = mcKey.ReadByte(ki++) ^ encrypted[i];
decrypted[i] = (byte)((b << 4) | (b >> 4));
if (ki >= keyEnd)
ki = keyReset;
}
return decrypted;
}
byte[] Decrypt9_v5(byte[] encrypted) {
return Decrypt9(encrypted, 0x11, 0x11, 0x610);
}
byte[] Decrypt9_v6(byte[] encrypted) {
return Decrypt9(encrypted, 0x2E, 0x2E, 0x310);
}
byte[] Decrypt9_v7(byte[] encrypted) {
return Decrypt9(encrypted, 0x28, 0x28, 0x510);
}
byte[] Decrypt9_v8(byte[] encrypted) {
return Decrypt9(encrypted, 0x2C, 0x2C, 0x510);
}
byte[] Decrypt9_v9(byte[] encrypted) {
return Decrypt9(encrypted, 0x10, 0x10, 0x510);
}
byte[] Decrypt9_v10(byte[] encrypted) {
return Decrypt9(encrypted, 5, 5, 0x510);
}
byte[] Decrypt9_v11(byte[] encrypted) {
return Decrypt9(encrypted, 0x19, 0x19, 0x500);
}
byte[] Decrypt9_v12(byte[] encrypted) {
return Decrypt9(encrypted, 0x19, 0x19, 0x500);
}
byte[] Decrypt9_v13(byte[] encrypted) {
return Decrypt9(encrypted, 5, 5, 0x510);
}
byte[] Decrypt9(byte[] encrypted, int keyStart, int keyReset, int keyEnd) {
var decrypted = new byte[encrypted.Length];
int ki = keyStart;
for (int i = 0; ; ) {
byte b, k;
if (i >= encrypted.Length) break;
k = mcKey.ReadByte(ki++);
b = encrypted[i];
b ^= k;
decrypted[i] = b;
i++;
if (ki >= keyEnd) ki = keyReset;
if (i >= encrypted.Length) break;
k = mcKey.ReadByte(ki++);
b = encrypted[i];
b ^= k;
b = (byte)((b << 4) | (b >> 4));
decrypted[i] = b;
i++;
if (ki >= keyEnd) ki = keyReset;
if (i >= encrypted.Length) break;
b = encrypted[i];
b = (byte)((b << 4) | (b >> 4));
decrypted[i] = b;
ki++;
i++;
if (ki >= keyEnd) ki = keyReset;
}
return decrypted;
}
byte[] Decrypt10(byte[] encrypted) {
byte[] enc = (byte[])encrypted.Clone();
byte[] dest = new byte[enc.Length];
int halfSize = enc.Length / 2;
byte b = enc[0];
b ^= 0xA1;
dest[0] = b;
b = enc[enc.Length - 1];
b ^= 0x1A;
dest[enc.Length - 1] = b;
enc[0] = dest[0];
enc[enc.Length - 1] = b;
for (int i = 1; i < halfSize; i++)
dest[i] = (byte)(enc[i] ^ dest[i - 1]);
for (int i = enc.Length - 2; i >= halfSize; i--)
dest[i] = (byte)(enc[i] ^ dest[i + 1]);
return dest;
}
byte[] Decrypt11_v1(byte[] encrypted) {
return Decrypt11(encrypted, 5, 5, 0x510);
}
byte[] Decrypt11(byte[] encrypted, int keyStart, int keyReset, int keyEnd) {
byte[] dest = new byte[encrypted.Length];
for (int i = 0, ki = keyStart; i < encrypted.Length; i++, ki++) {
if (ki >= keyEnd)
ki = keyStart;
byte b;
switch (i % 3) {
case 0:
dest[i] = (byte)(encrypted[i] ^ mcKey.ReadByte(ki));
break;
case 1:
b = (byte)(encrypted[i] ^ mcKey.ReadByte(ki));
dest[i] = (byte)((b << 4) | (b >> 4));
break;
case 2:
b = encrypted[i];
dest[i] = (byte)((b << 4) | (b >> 4));
break;
}
}
return dest;
}
byte[] blowfishKey;
byte[] GetBlowfishKey() {
if (blowfishKey != null)
return blowfishKey;
var key = new byte[100];
int i;
for (i = 0; i < key.Length; i++) {
byte b = mcKey.ReadByte(i);
if (b == 0)
break;
key[i] = b;
}
for (; i < key.Length; i++)
key[i] = 0;
key[key.Length - 1] = 0;
return blowfishKey = key;
}
}
public MethodsDecrypter(ModuleDef module, DecrypterInfo decrypterInfo) {
this.module = module;
this.decrypterInfo = decrypterInfo;
}
public bool Decrypt(ref DumpedMethods dumpedMethods) {
dumpedMethods = DecryptMethods();
if (dumpedMethods == null)
return false;
DecryptResources();
DecryptStrings();
return true;
}
DumpedMethods DecryptMethods() {
var dumpedMethods = new DumpedMethods();
var peImage = decrypterInfo.peImage;
var methodInfos = new MethodInfos(module, decrypterInfo.mainType, peImage, decrypterInfo.peHeader, decrypterInfo.mcKey);
methodInfos.InitializeInfos();
var methodDef = peImage.MetaData.TablesStream.MethodTable;
for (uint rid = 1; rid <= methodDef.Rows; rid++) {
var dm = new DumpedMethod();
peImage.ReadMethodTableRowTo(dm, rid);
var info = methodInfos.Lookup(dm.mdRVA);
if (info == null)
continue;
ushort magic = peImage.ReadUInt16(dm.mdRVA);
if (magic != 0xFFF3)
continue;
var mbHeader = MethodBodyParser.ParseMethodBody(MemoryImageStream.Create(info.body), out dm.code, out dm.extraSections);
peImage.UpdateMethodHeaderInfo(dm, mbHeader);
dumpedMethods.Add(dm);
}
return dumpedMethods;
}
void DecryptResources() {
var peHeader = decrypterInfo.peHeader;
var mcKey = decrypterInfo.mcKey;
var peImage = decrypterInfo.peImage;
var fileData = decrypterInfo.fileData;
uint decryptedResources = peHeader.ReadUInt32(0xFE8) ^ mcKey.ReadUInt32(0);
uint resourceRva = peHeader.GetRva(0x0E10, mcKey.ReadUInt32(0x00A0));
int resourceSize = (int)(peHeader.ReadUInt32(0x0E14) ^ mcKey.ReadUInt32(0x00AA));
if (decryptedResources == 1) {
Logger.v("Resources have already been decrypted");
return;
}
if (resourceRva == 0 || resourceSize <= 0)
return;
if (resourceRva != (uint)peImage.Cor20Header.Resources.VirtualAddress ||
resourceSize != peImage.Cor20Header.Resources.Size) {
Logger.w("Invalid resource RVA and size found");
}
Logger.v("Decrypting resources @ RVA {0:X8}, {1} bytes", resourceRva, resourceSize);
int resourceOffset = (int)peImage.RvaToOffset(resourceRva);
for (int i = 0; i < resourceSize; i++)
fileData[resourceOffset + i] ^= mcKey[i % 0x2000];
}
void DecryptStrings() {
var peHeader = decrypterInfo.peHeader;
var mcKey = decrypterInfo.mcKey;
var peImage = decrypterInfo.peImage;
var fileData = decrypterInfo.fileData;
uint usHeapRva = peHeader.GetRva(0x0E00, mcKey.ReadUInt32(0x0078));
uint usHeapSize = peHeader.ReadUInt32(0x0E04) ^ mcKey.ReadUInt32(0x0082);
if (usHeapRva == 0 || usHeapSize == 0)
return;
var usHeap = peImage.MetaData.USStream;
if (usHeap.StartOffset == 0 || // Start offset is 0 if it's not present in the file
peImage.RvaToOffset(usHeapRva) != (uint)usHeap.StartOffset ||
usHeapSize != (uint)(usHeap.EndOffset - usHeap.StartOffset)) {
Logger.w("Invalid #US heap RVA and size found");
}
Logger.v("Decrypting strings @ RVA {0:X8}, {1} bytes", usHeapRva, usHeapSize);
Logger.Instance.Indent();
int mcKeyOffset = 0;
int usHeapOffset = (int)peImage.RvaToOffset(usHeapRva);
int usHeapEnd = usHeapOffset + (int)usHeapSize;
usHeapOffset++;
while (usHeapOffset < usHeapEnd) {
if (fileData[usHeapOffset] == 0 || fileData[usHeapOffset] == 1) {
usHeapOffset++;
continue;
}
int usHeapOffsetOrig = usHeapOffset;
int stringDataLength = DeobUtils.ReadVariableLengthInt32(fileData, ref usHeapOffset);
int usHeapOffsetString = usHeapOffset;
int encryptedLength = stringDataLength - (usHeapOffset - usHeapOffsetOrig == 1 ? 1 : 2);
for (int i = 0; i < encryptedLength; i++) {
byte k = mcKey.ReadByte(mcKeyOffset++ % 0x2000);
fileData[usHeapOffset] = Rolb((byte)(fileData[usHeapOffset] ^ k), 3);
usHeapOffset++;
}
try {
Logger.v("Decrypted string: {0}", Utils.ToCsharpString(Encoding.Unicode.GetString(fileData, usHeapOffsetString, stringDataLength - 1)));
}
catch {
Logger.v("Could not decrypt string at offset {0:X8}", usHeapOffsetOrig);
}
usHeapOffset++;
}
Logger.Instance.DeIndent();
}
byte Rolb(byte b, int n) {
return (byte)((b << n) | (b >> (8 - n)));
}
}
}