Support new .NET Reactor resource encryption
This commit is contained in:
parent
408acb6685
commit
9b2ed7acca
|
@ -333,6 +333,9 @@ namespace de4dot.code.deobfuscators.dotNET_Reactor.v4 {
|
||||||
break;
|
break;
|
||||||
}
|
}
|
||||||
|
|
||||||
|
if (methodsDecrypter.DecrypterTypeVersion != DnrDecrypterType.V1)
|
||||||
|
return DeobfuscatorInfo.THE_NAME;
|
||||||
|
|
||||||
if (methodsDecrypter.Method == null) {
|
if (methodsDecrypter.Method == null) {
|
||||||
if (minVer >= 3800)
|
if (minVer >= 3800)
|
||||||
return DeobfuscatorInfo.THE_NAME + " >= 3.8";
|
return DeobfuscatorInfo.THE_NAME + " >= 3.8";
|
||||||
|
|
|
@ -24,13 +24,24 @@ using System.Security.Cryptography;
|
||||||
using dnlib.DotNet;
|
using dnlib.DotNet;
|
||||||
using dnlib.DotNet.Emit;
|
using dnlib.DotNet.Emit;
|
||||||
using de4dot.blocks;
|
using de4dot.blocks;
|
||||||
|
using de4dot.blocks.cflow;
|
||||||
|
|
||||||
namespace de4dot.code.deobfuscators.dotNET_Reactor.v4 {
|
namespace de4dot.code.deobfuscators.dotNET_Reactor.v4 {
|
||||||
|
enum DnrDecrypterType {
|
||||||
|
Unknown,
|
||||||
|
V1,
|
||||||
|
V2,
|
||||||
|
}
|
||||||
|
|
||||||
class EncryptedResource {
|
class EncryptedResource {
|
||||||
ModuleDefMD module;
|
ModuleDefMD module;
|
||||||
MethodDef resourceDecrypterMethod;
|
MethodDef resourceDecrypterMethod;
|
||||||
EmbeddedResource encryptedDataResource;
|
EmbeddedResource encryptedDataResource;
|
||||||
byte[] key, iv;
|
IDecrypter decrypter;
|
||||||
|
|
||||||
|
public DnrDecrypterType DecrypterTypeVersion {
|
||||||
|
get { return decrypter == null ? DnrDecrypterType.Unknown : decrypter.DecrypterType; }
|
||||||
|
}
|
||||||
|
|
||||||
public TypeDef Type {
|
public TypeDef Type {
|
||||||
get { return resourceDecrypterMethod == null ? null : resourceDecrypterMethod.DeclaringType; }
|
get { return resourceDecrypterMethod == null ? null : resourceDecrypterMethod.DeclaringType; }
|
||||||
|
@ -58,8 +69,7 @@ namespace de4dot.code.deobfuscators.dotNET_Reactor.v4 {
|
||||||
resourceDecrypterMethod = Lookup(oldOne.resourceDecrypterMethod, "Could not find resource decrypter method");
|
resourceDecrypterMethod = Lookup(oldOne.resourceDecrypterMethod, "Could not find resource decrypter method");
|
||||||
if (oldOne.encryptedDataResource != null)
|
if (oldOne.encryptedDataResource != null)
|
||||||
encryptedDataResource = DotNetUtils.GetResource(module, oldOne.encryptedDataResource.Name.String) as EmbeddedResource;
|
encryptedDataResource = DotNetUtils.GetResource(module, oldOne.encryptedDataResource.Name.String) as EmbeddedResource;
|
||||||
key = oldOne.key;
|
this.decrypter = oldOne.decrypter;
|
||||||
iv = oldOne.iv;
|
|
||||||
|
|
||||||
if (encryptedDataResource == null && oldOne.encryptedDataResource != null)
|
if (encryptedDataResource == null && oldOne.encryptedDataResource != null)
|
||||||
throw new ApplicationException("Could not initialize EncryptedResource");
|
throw new ApplicationException("Could not initialize EncryptedResource");
|
||||||
|
@ -69,30 +79,12 @@ namespace de4dot.code.deobfuscators.dotNET_Reactor.v4 {
|
||||||
return DeobUtils.Lookup(module, def, errorMessage);
|
return DeobUtils.Lookup(module, def, errorMessage);
|
||||||
}
|
}
|
||||||
|
|
||||||
public bool CouldBeResourceDecrypter(MethodDef method, IEnumerable<string> additionalTypes) {
|
public bool CouldBeResourceDecrypter(MethodDef method, IList<string> additionalTypes) {
|
||||||
return CouldBeResourceDecrypter(method, additionalTypes, true);
|
return CouldBeResourceDecrypter(method, additionalTypes, true);
|
||||||
}
|
}
|
||||||
|
|
||||||
public bool CouldBeResourceDecrypter(MethodDef method, IEnumerable<string> additionalTypes, bool checkResource) {
|
public bool CouldBeResourceDecrypter(MethodDef method, IList<string> additionalTypes, bool checkResource) {
|
||||||
if (!method.IsStatic)
|
if (GetDecrypterType(method, additionalTypes) == DnrDecrypterType.Unknown)
|
||||||
return false;
|
|
||||||
if (method.Body == null)
|
|
||||||
return false;
|
|
||||||
|
|
||||||
var localTypes = new LocalTypes(method);
|
|
||||||
var requiredTypes = new List<string> {
|
|
||||||
"System.Byte[]",
|
|
||||||
"System.IO.BinaryReader",
|
|
||||||
"System.IO.MemoryStream",
|
|
||||||
"System.Security.Cryptography.CryptoStream",
|
|
||||||
"System.Security.Cryptography.ICryptoTransform",
|
|
||||||
};
|
|
||||||
requiredTypes.AddRange(additionalTypes);
|
|
||||||
if (!localTypes.All(requiredTypes))
|
|
||||||
return false;
|
|
||||||
if (!localTypes.Exists("System.Security.Cryptography.RijndaelManaged") &&
|
|
||||||
!localTypes.Exists("System.Security.Cryptography.AesManaged") &&
|
|
||||||
!localTypes.Exists("System.Security.Cryptography.SymmetricAlgorithm"))
|
|
||||||
return false;
|
return false;
|
||||||
|
|
||||||
if (checkResource && FindMethodsDecrypterResource(method) == null)
|
if (checkResource && FindMethodsDecrypterResource(method) == null)
|
||||||
|
@ -101,6 +93,24 @@ namespace de4dot.code.deobfuscators.dotNET_Reactor.v4 {
|
||||||
return true;
|
return true;
|
||||||
}
|
}
|
||||||
|
|
||||||
|
public DnrDecrypterType GuessDecrypterType() {
|
||||||
|
return GetDecrypterType(resourceDecrypterMethod, null);
|
||||||
|
}
|
||||||
|
|
||||||
|
static DnrDecrypterType GetDecrypterType(MethodDef method, IList<string> additionalTypes) {
|
||||||
|
if (method == null || !method.IsStatic || method.Body == null)
|
||||||
|
return DnrDecrypterType.Unknown;
|
||||||
|
|
||||||
|
if (additionalTypes == null)
|
||||||
|
additionalTypes = new string[0];
|
||||||
|
var localTypes = new LocalTypes(method);
|
||||||
|
if (DecrypterV1.CouldBeResourceDecrypter(method, localTypes, additionalTypes))
|
||||||
|
return DnrDecrypterType.V1;
|
||||||
|
else if (DecrypterV2.CouldBeResourceDecrypter(method, localTypes, additionalTypes))
|
||||||
|
return DnrDecrypterType.V2;
|
||||||
|
return DnrDecrypterType.Unknown;
|
||||||
|
}
|
||||||
|
|
||||||
public void Initialize(ISimpleDeobfuscator simpleDeobfuscator) {
|
public void Initialize(ISimpleDeobfuscator simpleDeobfuscator) {
|
||||||
if (resourceDecrypterMethod == null)
|
if (resourceDecrypterMethod == null)
|
||||||
return;
|
return;
|
||||||
|
@ -111,10 +121,10 @@ namespace de4dot.code.deobfuscators.dotNET_Reactor.v4 {
|
||||||
if (encryptedDataResource == null)
|
if (encryptedDataResource == null)
|
||||||
return;
|
return;
|
||||||
|
|
||||||
key = ArrayFinder.GetInitializedByteArray(resourceDecrypterMethod, 32);
|
var key = ArrayFinder.GetInitializedByteArray(resourceDecrypterMethod, 32);
|
||||||
if (key == null)
|
if (key == null)
|
||||||
throw new ApplicationException("Could not find resource decrypter key");
|
throw new ApplicationException("Could not find resource decrypter key");
|
||||||
iv = ArrayFinder.GetInitializedByteArray(resourceDecrypterMethod, 16);
|
var iv = ArrayFinder.GetInitializedByteArray(resourceDecrypterMethod, 16);
|
||||||
if (iv == null)
|
if (iv == null)
|
||||||
throw new ApplicationException("Could not find resource decrypter IV");
|
throw new ApplicationException("Could not find resource decrypter IV");
|
||||||
if (NeedReverse())
|
if (NeedReverse())
|
||||||
|
@ -126,6 +136,13 @@ namespace de4dot.code.deobfuscators.dotNET_Reactor.v4 {
|
||||||
iv[i * 2 + 1] = publicKeyToken.Data[i];
|
iv[i * 2 + 1] = publicKeyToken.Data[i];
|
||||||
}
|
}
|
||||||
}
|
}
|
||||||
|
|
||||||
|
var decrypterType = GetDecrypterType(resourceDecrypterMethod, new string[0]);
|
||||||
|
switch (decrypterType) {
|
||||||
|
case DnrDecrypterType.V1: decrypter = new DecrypterV1(iv, key); break;
|
||||||
|
case DnrDecrypterType.V2: decrypter = new DecrypterV2(iv, key, resourceDecrypterMethod); break;
|
||||||
|
default: throw new ApplicationException("Unknown decrypter type");
|
||||||
|
}
|
||||||
}
|
}
|
||||||
|
|
||||||
static int[] pktIndexes = new int[16] { 1, 0, 3, 1, 5, 2, 7, 3, 9, 4, 11, 5, 13, 6, 15, 7 };
|
static int[] pktIndexes = new int[16] { 1, 0, 3, 1, 5, 2, 7, 3, 9, 4, 11, 5, 13, 6, 15, 7 };
|
||||||
|
@ -162,22 +179,244 @@ namespace de4dot.code.deobfuscators.dotNET_Reactor.v4 {
|
||||||
return null;
|
return null;
|
||||||
}
|
}
|
||||||
|
|
||||||
public byte[] Decrypt() {
|
interface IDecrypter {
|
||||||
if (encryptedDataResource == null || key == null || iv == null)
|
DnrDecrypterType DecrypterType { get; }
|
||||||
throw new ApplicationException("Can't decrypt resource");
|
byte[] Decrypt(EmbeddedResource resource);
|
||||||
|
byte[] Encrypt(byte[] data);
|
||||||
return DeobUtils.AesDecrypt(encryptedDataResource.GetResourceData(), key, iv);
|
|
||||||
}
|
}
|
||||||
|
|
||||||
public byte[] Encrypt(byte[] data) {
|
class DecrypterV1 : IDecrypter {
|
||||||
if (key == null || iv == null)
|
readonly byte[] key, iv;
|
||||||
throw new ApplicationException("Can't encrypt resource");
|
|
||||||
|
|
||||||
using (var aes = new RijndaelManaged { Mode = CipherMode.CBC }) {
|
public DnrDecrypterType DecrypterType {
|
||||||
using (var transform = aes.CreateEncryptor(key, iv)) {
|
get { return DnrDecrypterType.V1; }
|
||||||
return transform.TransformFinalBlock(data, 0, data.Length);
|
}
|
||||||
|
|
||||||
|
public DecrypterV1(byte[] iv, byte[] key) {
|
||||||
|
this.iv = iv;
|
||||||
|
this.key = key;
|
||||||
|
}
|
||||||
|
|
||||||
|
public static bool CouldBeResourceDecrypter(MethodDef method, LocalTypes localTypes, IList<string> additionalTypes) {
|
||||||
|
var requiredTypes = new List<string> {
|
||||||
|
"System.Byte[]",
|
||||||
|
"System.IO.BinaryReader",
|
||||||
|
"System.IO.MemoryStream",
|
||||||
|
"System.Security.Cryptography.CryptoStream",
|
||||||
|
"System.Security.Cryptography.ICryptoTransform",
|
||||||
|
};
|
||||||
|
requiredTypes.AddRange(additionalTypes);
|
||||||
|
if (!localTypes.All(requiredTypes))
|
||||||
|
return false;
|
||||||
|
if (!localTypes.Exists("System.Security.Cryptography.RijndaelManaged") &&
|
||||||
|
!localTypes.Exists("System.Security.Cryptography.AesManaged") &&
|
||||||
|
!localTypes.Exists("System.Security.Cryptography.SymmetricAlgorithm"))
|
||||||
|
return false;
|
||||||
|
|
||||||
|
return true;
|
||||||
|
}
|
||||||
|
|
||||||
|
public byte[] Decrypt(EmbeddedResource resource) {
|
||||||
|
return DeobUtils.AesDecrypt(resource.GetResourceData(), key, iv);
|
||||||
|
}
|
||||||
|
|
||||||
|
public byte[] Encrypt(byte[] data) {
|
||||||
|
using (var aes = new RijndaelManaged { Mode = CipherMode.CBC }) {
|
||||||
|
using (var transform = aes.CreateEncryptor(key, iv)) {
|
||||||
|
return transform.TransformFinalBlock(data, 0, data.Length);
|
||||||
|
}
|
||||||
}
|
}
|
||||||
}
|
}
|
||||||
}
|
}
|
||||||
|
|
||||||
|
class DecrypterV2 : IDecrypter {
|
||||||
|
readonly byte[] key, iv;
|
||||||
|
readonly MethodDef method;
|
||||||
|
List<Instruction> instructions;
|
||||||
|
readonly List<Local> locals;
|
||||||
|
readonly InstructionEmulator instrEmulator = new InstructionEmulator();
|
||||||
|
Local emuLocal;
|
||||||
|
|
||||||
|
public DnrDecrypterType DecrypterType {
|
||||||
|
get { return DnrDecrypterType.V2; }
|
||||||
|
}
|
||||||
|
|
||||||
|
public DecrypterV2(byte[] iv, byte[] key, MethodDef method) {
|
||||||
|
this.iv = iv;
|
||||||
|
this.key = key;
|
||||||
|
this.method = method;
|
||||||
|
this.locals = new List<Local>(method.Body.Variables);
|
||||||
|
if (!Initialize())
|
||||||
|
throw new ApplicationException("Could not initialize decrypter");
|
||||||
|
}
|
||||||
|
|
||||||
|
public static bool CouldBeResourceDecrypter(MethodDef method, LocalTypes localTypes, IList<string> additionalTypes) {
|
||||||
|
var requiredTypes = new List<string> {
|
||||||
|
"System.UInt32",
|
||||||
|
"System.String",
|
||||||
|
"System.Int32",
|
||||||
|
"System.Byte[]",
|
||||||
|
"System.IO.BinaryReader",
|
||||||
|
};
|
||||||
|
requiredTypes.AddRange(additionalTypes);
|
||||||
|
if (!localTypes.All(requiredTypes))
|
||||||
|
return false;
|
||||||
|
|
||||||
|
return true;
|
||||||
|
}
|
||||||
|
|
||||||
|
bool Initialize() {
|
||||||
|
for (int i = 0; i < iv.Length; i++)
|
||||||
|
key[i] ^= iv[i];
|
||||||
|
|
||||||
|
var origInstrs = method.Body.Instructions;
|
||||||
|
|
||||||
|
int emuStartIndex;
|
||||||
|
if (!FindStart(origInstrs, out emuStartIndex, out emuLocal))
|
||||||
|
return false;
|
||||||
|
int emuEndIndex;
|
||||||
|
if (!FindEnd(origInstrs, emuStartIndex, out emuEndIndex))
|
||||||
|
return false;
|
||||||
|
|
||||||
|
int count = emuEndIndex - emuStartIndex + 1;
|
||||||
|
instructions = new List<Instruction>(count);
|
||||||
|
for (int i = 0; i < count; i++)
|
||||||
|
instructions.Add(origInstrs[emuStartIndex + i].Clone());
|
||||||
|
|
||||||
|
return true;
|
||||||
|
}
|
||||||
|
|
||||||
|
bool FindStart(IList<Instruction> instrs, out int startIndex, out Local tmpLocal) {
|
||||||
|
for (int i = 0; i + 8 < instrs.Count; i++) {
|
||||||
|
if (instrs[i].OpCode.Code != Code.Conv_U)
|
||||||
|
continue;
|
||||||
|
if (instrs[i + 1].OpCode.Code != Code.Ldelem_U1)
|
||||||
|
continue;
|
||||||
|
if (instrs[i + 2].OpCode.Code != Code.Or)
|
||||||
|
continue;
|
||||||
|
if (CheckLocal(instrs[i + 3], false) == null)
|
||||||
|
continue;
|
||||||
|
Local local;
|
||||||
|
if ((local = CheckLocal(instrs[i + 4], true)) == null)
|
||||||
|
continue;
|
||||||
|
if (CheckLocal(instrs[i + 5], true) == null)
|
||||||
|
continue;
|
||||||
|
if (instrs[i + 6].OpCode.Code != Code.Add)
|
||||||
|
continue;
|
||||||
|
if (CheckLocal(instrs[i + 7], false) != local)
|
||||||
|
continue;
|
||||||
|
var instr = instrs[i + 8];
|
||||||
|
int newStartIndex = i + 8;
|
||||||
|
if (instr.IsBr()) {
|
||||||
|
instr = instr.Operand as Instruction;
|
||||||
|
newStartIndex = instrs.IndexOf(instr);
|
||||||
|
}
|
||||||
|
if (newStartIndex < 0 || instr == null)
|
||||||
|
continue;
|
||||||
|
if (CheckLocal(instr, true) != local)
|
||||||
|
continue;
|
||||||
|
|
||||||
|
startIndex = newStartIndex;
|
||||||
|
tmpLocal = local;
|
||||||
|
return true;
|
||||||
|
}
|
||||||
|
|
||||||
|
startIndex = 0;
|
||||||
|
tmpLocal = null;
|
||||||
|
return false;
|
||||||
|
}
|
||||||
|
|
||||||
|
bool FindEnd(IList<Instruction> instrs, int startIndex, out int endIndex) {
|
||||||
|
for (int i = startIndex; i < instrs.Count; i++) {
|
||||||
|
var instr = instrs[i];
|
||||||
|
if (instr.OpCode.FlowControl != FlowControl.Next)
|
||||||
|
break;
|
||||||
|
if (instr.IsStloc() && instr.GetLocal(locals) == emuLocal) {
|
||||||
|
endIndex = i - 1;
|
||||||
|
return true;
|
||||||
|
}
|
||||||
|
}
|
||||||
|
|
||||||
|
endIndex = 0;
|
||||||
|
return false;
|
||||||
|
}
|
||||||
|
|
||||||
|
Local CheckLocal(Instruction instr, bool isLdloc) {
|
||||||
|
if (isLdloc && !instr.IsLdloc())
|
||||||
|
return null;
|
||||||
|
else if (!isLdloc && !instr.IsStloc())
|
||||||
|
return null;
|
||||||
|
|
||||||
|
return instr.GetLocal(locals);
|
||||||
|
}
|
||||||
|
|
||||||
|
public byte[] Decrypt(EmbeddedResource resource) {
|
||||||
|
var encrypted = resource.GetResourceData();
|
||||||
|
var decrypted = new byte[encrypted.Length];
|
||||||
|
|
||||||
|
uint sum = 0;
|
||||||
|
for (int i = 0; i < encrypted.Length; i += 4) {
|
||||||
|
sum = CalculateMagic(sum + ReadUInt32(key, i % key.Length));
|
||||||
|
WriteUInt32(decrypted, i, sum ^ ReadUInt32(encrypted, i));
|
||||||
|
}
|
||||||
|
|
||||||
|
return decrypted;
|
||||||
|
}
|
||||||
|
|
||||||
|
uint CalculateMagic(uint input) {
|
||||||
|
instrEmulator.Initialize(method, method.Parameters, locals, method.Body.InitLocals, false);
|
||||||
|
instrEmulator.SetLocal(emuLocal, new Int32Value((int)input));
|
||||||
|
|
||||||
|
foreach (var instr in instructions)
|
||||||
|
instrEmulator.Emulate(instr);
|
||||||
|
|
||||||
|
var tos = instrEmulator.Pop() as Int32Value;
|
||||||
|
if (tos == null || !tos.AllBitsValid())
|
||||||
|
throw new ApplicationException("Couldn't calculate magic value");
|
||||||
|
return (uint)tos.Value;
|
||||||
|
}
|
||||||
|
|
||||||
|
static uint ReadUInt32(byte[] ary, int index) {
|
||||||
|
int sizeLeft = ary.Length - index;
|
||||||
|
if (sizeLeft >= 4)
|
||||||
|
return BitConverter.ToUInt32(ary, index);
|
||||||
|
switch (sizeLeft) {
|
||||||
|
case 1: return ary[index];
|
||||||
|
case 2: return (uint)(ary[index] | (ary[index + 1] << 8));
|
||||||
|
case 3: return (uint)(ary[index] | (ary[index + 1] << 8) | (ary[index + 2] << 16));
|
||||||
|
default: throw new ApplicationException("Can't read data");
|
||||||
|
}
|
||||||
|
}
|
||||||
|
|
||||||
|
static void WriteUInt32(byte[] ary, int index, uint value) {
|
||||||
|
int sizeLeft = ary.Length - index;
|
||||||
|
if (sizeLeft >= 1)
|
||||||
|
ary[index] = (byte)value;
|
||||||
|
if (sizeLeft >= 2)
|
||||||
|
ary[index + 1] = (byte)(value >> 8);
|
||||||
|
if (sizeLeft >= 3)
|
||||||
|
ary[index + 2] = (byte)(value >> 16);
|
||||||
|
if (sizeLeft >= 4)
|
||||||
|
ary[index + 3] = (byte)(value >> 24);
|
||||||
|
}
|
||||||
|
|
||||||
|
public byte[] Encrypt(byte[] data) {
|
||||||
|
//TODO: Support re-encryption
|
||||||
|
Logger.e("Re-encryption is not supported. Assembly will probably crash at runtime.");
|
||||||
|
return (byte[])data.Clone();
|
||||||
|
}
|
||||||
|
}
|
||||||
|
|
||||||
|
public byte[] Decrypt() {
|
||||||
|
if (encryptedDataResource == null || decrypter == null)
|
||||||
|
throw new ApplicationException("Can't decrypt resource");
|
||||||
|
return decrypter.Decrypt(encryptedDataResource);
|
||||||
|
}
|
||||||
|
|
||||||
|
public byte[] Encrypt(byte[] data) {
|
||||||
|
if (decrypter == null)
|
||||||
|
throw new ApplicationException("Can't encrypt resource");
|
||||||
|
return decrypter.Encrypt(data);
|
||||||
|
}
|
||||||
}
|
}
|
||||||
}
|
}
|
||||||
|
|
|
@ -57,6 +57,10 @@ namespace de4dot.code.deobfuscators.dotNET_Reactor.v4 {
|
||||||
get { return encryptedResource.Resource; }
|
get { return encryptedResource.Resource; }
|
||||||
}
|
}
|
||||||
|
|
||||||
|
public DnrDecrypterType DecrypterTypeVersion {
|
||||||
|
get { return encryptedResource.GuessDecrypterType(); }
|
||||||
|
}
|
||||||
|
|
||||||
public MethodsDecrypter(ModuleDefMD module) {
|
public MethodsDecrypter(ModuleDefMD module) {
|
||||||
this.module = module;
|
this.module = module;
|
||||||
this.encryptedResource = new EncryptedResource(module);
|
this.encryptedResource = new EncryptedResource(module);
|
||||||
|
@ -301,10 +305,10 @@ namespace de4dot.code.deobfuscators.dotNET_Reactor.v4 {
|
||||||
if (instructions[i].OpCode.Code != Code.Ldind_I8)
|
if (instructions[i].OpCode.Code != Code.Ldind_I8)
|
||||||
continue;
|
continue;
|
||||||
var ldci4 = instructions[i + 1];
|
var ldci4 = instructions[i + 1];
|
||||||
if (!ldci4.IsLdcI4())
|
if (ldci4.IsLdcI4())
|
||||||
continue;
|
return ldci4.GetLdcI4Value();
|
||||||
|
if (ldci4.OpCode.Code == Code.Ldc_I8)
|
||||||
return ldci4.GetLdcI4Value();
|
return (long)ldci4.Operand;
|
||||||
}
|
}
|
||||||
return 0;
|
return 0;
|
||||||
}
|
}
|
||||||
|
|
Loading…
Reference in New Issue
Block a user