monocul.us/de4dot-cex
1
0
Fork 0
Code Issues Pull Requests Packages Projects Releases Wiki Activity

Support v3.0

Browse Source
This commit is contained in:
de4dot 2012-01-14 10:37:15 +01:00
parent cc85005ba0
commit 6b4a462757
3 changed files with 191 additions and 54 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

2
de4dot.code/deobfuscators/Babel_NET/Deobfuscator.cs
View File

@ -175,7 +175,7 @@ namespace de4dot.code.deobfuscators.Babel_NET {
if (stringDecrypter.Resource != null) {
Log.v("Adding string decrypter. Resource: {0}", Utils.toCsharpString(stringDecrypter.Resource.Name));
staticStringDecrypter.add(stringDecrypter.DecryptMethod, (method, args) => {
return stringDecrypter.decrypt((int)args[0]);
return stringDecrypter.decrypt(args);
});
DeobfuscatedFile.stringDecryptersAdded();
}

42
de4dot.code/deobfuscators/Babel_NET/ResourceDecrypter.cs
View File

@ -30,13 +30,51 @@ namespace de4dot.code.deobfuscators.Babel_NET {
}
public byte[] decrypt(byte[] encryptedData) {
if (isV30(encryptedData))
return decryptV30(encryptedData);
return decryptV35(encryptedData);
}
static bool isV30(byte[] data) {
return data.Length > 10 && data[0] == 8 && data[9] <= 1 && data[10] == 8;
}
// v3.0
byte[] decryptV30(byte[] encryptedData) {
byte[] key, iv;
var reader = new BinaryReader(new MemoryStream(encryptedData));
bool isCompressed = getHeaderData30(reader, out key, out iv);
var data = DeobUtils.desDecrypt(encryptedData,
(int)reader.BaseStream.Position,
(int)(reader.BaseStream.Length - reader.BaseStream.Position),
key, iv);
if (isCompressed)
data = DeobUtils.inflate(data, true);
return data;
}
bool getHeaderData30(BinaryReader reader, out byte[] key, out byte[] iv) {
iv = reader.ReadBytes(reader.ReadByte());
bool hasEmbeddedKey = reader.ReadBoolean();
if (hasEmbeddedKey)
key = reader.ReadBytes(reader.ReadByte());
else {
key = new byte[reader.ReadByte()];
Array.Copy(module.Assembly.Name.PublicKey, 0, key, 0, key.Length);
}
reader.ReadBytes(reader.ReadInt32()); // hash
return true;
}
// v3.5+
byte[] decryptV35(byte[] encryptedData) {
int index = 0;
byte[] key, iv;
bool isCompressed = getKeyIv(getHeaderData(encryptedData, ref index), out key, out iv);
var data = DeobUtils.desDecrypt(encryptedData, index, encryptedData.Length - index, key, iv);
if (isCompressed)
data = DeobUtils.inflate(data, true);
return data;
}
@ -59,7 +97,7 @@ namespace de4dot.code.deobfuscators.Babel_NET {
bool getKeyIv(byte[] headerData, out byte[] key, out byte[] iv) {
var reader = new BinaryReader(new MemoryStream(headerData));
// 3.5 doesn't have this field
// 3.0 - 3.5 don't have this field
if (headerData[(int)reader.BaseStream.Position] != 8) {
var license = reader.ReadString();
}

201
de4dot.code/deobfuscators/Babel_NET/StringDecrypter.cs
View File

@ -17,18 +17,77 @@
along with de4dot. If not, see <http://www.gnu.org/licenses/>.
*/
using System;
using System.Collections.Generic;
using System.IO;
using System.Text;
using Mono.Cecil;
using de4dot.blocks;
namespace de4dot.code.deobfuscators.Babel_NET {
class StringDecrypter {
ModuleDefinition module;
Dictionary<int, string> offsetToString = new Dictionary<int, string>();
TypeDefinition decrypterType;
MethodDefinition decryptMethod;
EmbeddedResource encryptedResource;
IDecrypterInfo decrypterInfo;
interface IDecrypterInfo {
MethodDefinition Decrypter { get; }
bool NeedsResource { get; }
void initialize(ModuleDefinition module, EmbeddedResource resource);
string decrypt(object[] args);
}
class DecrypterInfoV1 : IDecrypterInfo {
byte[] key;
public MethodDefinition Decrypter { get; set; }
public bool NeedsResource {
get { return true; }
}
public void initialize(ModuleDefinition module, EmbeddedResource resource) {
key = resource.GetResourceData();
if (key.Length != 0x100)
throw new ApplicationException(string.Format("Unknown key length: {0}", key.Length));
}
public string decrypt(object[] args) {
return decrypt((string)args[0], (int)args[1]);
}
string decrypt(string s, int k) {
var sb = new StringBuilder(s.Length);
byte b = key[(byte)k];
foreach (var c in s)
sb.Append((char)(c ^ (b | k)));
return sb.ToString();
}
}
class DecrypterInfoV2 : IDecrypterInfo {
Dictionary<int, string> offsetToString = new Dictionary<int, string>();
public MethodDefinition Decrypter { get; set; }
public bool NeedsResource {
get { return true; }
}
public void initialize(ModuleDefinition module, EmbeddedResource resource) {
var decrypted = new ResourceDecrypter(module).decrypt(resource.GetResourceData());
var reader = new BinaryReader(new MemoryStream(decrypted));
while (reader.BaseStream.Position < reader.BaseStream.Length)
offsetToString[(int)reader.BaseStream.Position] = reader.ReadString();
}
public string decrypt(object[] args) {
return decrypt((int)args[0]);
}
string decrypt(int offset) {
return offsetToString[offset];
}
}
public bool Detected {
get { return decrypterType != null; }
@ -39,7 +98,7 @@ namespace de4dot.code.deobfuscators.Babel_NET {
}
public MethodDefinition DecryptMethod {
get { return decryptMethod; }
get { return decrypterInfo == null ? null : decrypterInfo.Decrypter; }
}
public EmbeddedResource Resource {
@ -52,58 +111,98 @@ namespace de4dot.code.deobfuscators.Babel_NET {
public void find() {
foreach (var type in module.Types) {
if (!isDecrypterType(type))
continue;
var method = DotNetUtils.getMethod(type, "System.String", "(System.Int32)");
if (method == null)
var info = checkDecrypterType(type);
if (info == null)
continue;
decrypterType = type;
decryptMethod = method;
decrypterInfo = info;
return;
}
}
bool isDecrypterType(TypeDefinition type) {
IDecrypterInfo checkDecrypterType(TypeDefinition type) {
if (type.HasEvents)
return false;
if (type.NestedTypes.Count != 1)
return false;
if (type.Fields.Count != 0)
return false;
return null;
if (type.NestedTypes.Count > 2)
return null;
if (type.Fields.Count > 1)
return null;
var nested = type.NestedTypes[0];
foreach (var nested in type.NestedTypes) {
var info = checkNested(type, nested);
if (info != null)
return info;
}
return null;
}
IDecrypterInfo checkNested(TypeDefinition type, TypeDefinition nested) {
if (nested.HasProperties || nested.HasEvents)
return false;
if (nested.Fields.Count == 1) {
// 4.2+ (maybe 4.0+)
if (!MemberReferenceHelper.compareTypes(nested.Fields[0].FieldType, nested))
return false;
if (DotNetUtils.getMethod(nested, "System.Reflection.Emit.MethodBuilder", "(System.Reflection.Emit.TypeBuilder)") == null)
return false;
}
else if (nested.Fields.Count == 2) {
// 3.5 and maybe earlier
var field1 = nested.Fields[0];
var field2 = nested.Fields[1];
if (field1.FieldType.FullName != "System.Collections.Hashtable" && field2.FieldType.FullName != "System.Collections.Hashtable")
return false;
if (!MemberReferenceHelper.compareTypes(field1.FieldType, nested) && !MemberReferenceHelper.compareTypes(field2.FieldType, nested))
return false;
}
else
return false;
return null;
if (DotNetUtils.getMethod(nested, ".ctor") == null)
return false;
if (DotNetUtils.getMethod(nested, "System.String", "(System.Int32)") == null)
return false;
return null;
if (nested.Fields.Count == 1) {
// 4.0+
if (!MemberReferenceHelper.compareTypes(nested.Fields[0].FieldType, nested))
return null;
if (DotNetUtils.getMethod(nested, "System.Reflection.Emit.MethodBuilder", "(System.Reflection.Emit.TypeBuilder)") == null)
return null;
var nestedDecrypter = DotNetUtils.getMethod(nested, "System.String", "(System.Int32)");
if (nestedDecrypter == null || nestedDecrypter.IsStatic)
return null;
var decrypter = DotNetUtils.getMethod(type, "System.String", "(System.Int32)");
if (decrypter == null || !decrypter.IsStatic)
return null;
return new DecrypterInfoV2 { Decrypter = decrypter };
}
else if (nested.Fields.Count == 2) {
// 3.0 - 3.5
if (checkFields(nested, "System.Collections.Hashtable", nested)) {
// 3.5
var nestedDecrypter = DotNetUtils.getMethod(nested, "System.String", "(System.Int32)");
if (nestedDecrypter == null || nestedDecrypter.IsStatic)
return null;
var decrypter = DotNetUtils.getMethod(type, "System.String", "(System.Int32)");
if (decrypter == null || !decrypter.IsStatic)
return null;
return new DecrypterInfoV2 { Decrypter = decrypter };
}
else if (checkFields(nested, "System.Byte[]", nested)) {
// 3.0
var nestedDecrypter = DotNetUtils.getMethod(nested, "System.String", "(System.String,System.Int32)");
if (nestedDecrypter == null || nestedDecrypter.IsStatic)
return null;
var decrypter = DotNetUtils.getMethod(type, "System.String", "(System.String,System.Int32)");
if (decrypter == null || !decrypter.IsStatic)
return null;
return new DecrypterInfoV1 { Decrypter = decrypter };
}
else
return null;
}
return null;
}
bool checkFields(TypeDefinition type, string fieldType1, TypeDefinition fieldType2) {
if (type.Fields.Count != 2)
return false;
if (type.Fields[0].FieldType.FullName != fieldType1 &&
type.Fields[1].FieldType.FullName != fieldType1)
return false;
if (!MemberReferenceHelper.compareTypes(type.Fields[0].FieldType, fieldType2) &&
!MemberReferenceHelper.compareTypes(type.Fields[1].FieldType, fieldType2))
return false;
return true;
}
@ -112,14 +211,14 @@ namespace de4dot.code.deobfuscators.Babel_NET {
return;
if (encryptedResource != null)
return;
encryptedResource = findResource();
if (encryptedResource == null)
return;
var decrypted = new ResourceDecrypter(module).decrypt(encryptedResource.GetResourceData());
var reader = new BinaryReader(new MemoryStream(decrypted));
while (reader.BaseStream.Position < reader.BaseStream.Length)
offsetToString[(int)reader.BaseStream.Position] = reader.ReadString();
if (decrypterInfo.NeedsResource) {
encryptedResource = findResource();
if (encryptedResource == null)
return;
}
decrypterInfo.initialize(module, encryptedResource);
}
EmbeddedResource findResource() {
@ -133,8 +232,8 @@ namespace de4dot.code.deobfuscators.Babel_NET {
return null;
}
public string decrypt(int offset) {
return offsetToString[offset];
public string decrypt(object[] args) {
return decrypterInfo.decrypt(args);
}
}
}