byte[] GetKeyData()
{
isNet1x = false;
for (int i = 0; i < baseOffsets.Length; i++)
{
var code = peImage.OffsetReadBytes(baseOffsets[i], decryptMethodPattern.Length);
if (DeobUtils.IsCode(decryptMethodPattern, code))
{
return(GetKeyData(baseOffsets[i]));
}
}
var net1xCode = peImage.OffsetReadBytes(0x207E0, startMethodNet1xPattern.Length);
if (DeobUtils.IsCode(startMethodNet1xPattern, net1xCode))
{
isNet1x = true;
return(new byte[6] {
0x34, 0x38, 0x63, 0x65, 0x7A, 0x35
});
}
return(null);
}
public bool Decrypt(MyPEImage peImage, ISimpleDeobfuscator simpleDeobfuscator, ref DumpedMethods dumpedMethods, Dictionary <uint, byte[]> tokenToNativeCode, bool unpackedNativeFile)
{
if (encryptedResource.Method == null)
{
return(false);
}
encryptedResource.Initialize(simpleDeobfuscator);
if (!encryptedResource.FoundResource)
{
return(false);
}
var methodsData = encryptedResource.Decrypt();
bool hooksJitter = FindDnrCompileMethod(encryptedResource.Method.DeclaringType) != null;
xorKey = GetXorKey();
XorEncrypt(methodsData);
var methodsDataReader = MemoryImageStream.Create(methodsData);
int patchCount = methodsDataReader.ReadInt32();
int mode = methodsDataReader.ReadInt32();
int tmp = methodsDataReader.ReadInt32();
methodsDataReader.Position -= 4;
if ((tmp & 0xFF000000) == 0x06000000)
{
// It's method token + rva. DNR 3.7.0.3 (and earlier?) - 3.9.0.1
methodsDataReader.Position += 8L * patchCount;
patchCount = methodsDataReader.ReadInt32();
mode = methodsDataReader.ReadInt32();
PatchDwords(peImage, methodsDataReader, patchCount);
while (methodsDataReader.Position < methodsData.Length - 1)
{
uint token = methodsDataReader.ReadUInt32();
int numDwords = methodsDataReader.ReadInt32();
PatchDwords(peImage, methodsDataReader, numDwords / 2);
}
}
else if (!hooksJitter || mode == 1)
{
// DNR 3.9.8.0, 4.0+
PatchDwords(peImage, methodsDataReader, patchCount);
bool oldCode = !IsNewer45Decryption(encryptedResource.Method);
while (methodsDataReader.Position < methodsData.Length - 1)
{
uint rva = methodsDataReader.ReadUInt32();
int size;
if (oldCode)
{
methodsDataReader.ReadUInt32(); // token, unknown, or index
size = methodsDataReader.ReadInt32();
}
else
{
size = methodsDataReader.ReadInt32() * 4;
}
var newData = methodsDataReader.ReadBytes(size);
if (unpackedNativeFile)
{
peImage.DotNetSafeWriteOffset(rva, newData);
}
else
{
peImage.DotNetSafeWrite(rva, newData);
}
}
}
else
{
// DNR 4.0+ (jitter is hooked)
var methodDef = peImage.MetaData.TablesStream.MethodTable;
var rvaToIndex = new Dictionary <uint, int>((int)methodDef.Rows);
uint offset = (uint)methodDef.StartOffset;
for (int i = 0; i < methodDef.Rows; i++)
{
uint rva = peImage.OffsetReadUInt32(offset);
offset += methodDef.RowSize;
if (rva == 0)
{
continue;
}
if ((peImage.ReadByte(rva) & 3) == 2)
{
rva++;
}
else
{
rva += (uint)(4 * (peImage.ReadByte(rva + 1) >> 4));
}
rvaToIndex[rva] = i;
}
PatchDwords(peImage, methodsDataReader, patchCount);
int count = methodsDataReader.ReadInt32();
dumpedMethods = new DumpedMethods();
while (methodsDataReader.Position < methodsData.Length - 1)
{
uint rva = methodsDataReader.ReadUInt32();
uint index = methodsDataReader.ReadUInt32();
bool isNativeCode = index >= 0x70000000;
int size = methodsDataReader.ReadInt32();
var methodData = methodsDataReader.ReadBytes(size);
int methodIndex;
if (!rvaToIndex.TryGetValue(rva, out methodIndex))
{
Logger.w("Could not find method having code RVA {0:X8}", rva);
continue;
}
uint methodToken = 0x06000001 + (uint)methodIndex;
if (isNativeCode)
{
totalEncryptedNativeMethods++;
if (tokenToNativeCode != null)
{
tokenToNativeCode[methodToken] = methodData;
}
// Convert return true / false methods. The others are converted to
// throw 0xDEADCODE.
if (DeobUtils.IsCode(nativeLdci4, methodData))
{
uint val = BitConverter.ToUInt32(methodData, 4);
// ldc.i4 XXXXXXXXh / ret
methodData = new byte[] { 0x20, 0, 0, 0, 0, 0x2A };
methodData[1] = (byte)val;
methodData[2] = (byte)(val >> 8);
methodData[3] = (byte)(val >> 16);
methodData[4] = (byte)(val >> 24);
}
else if (DeobUtils.IsCode(nativeLdci4_0, methodData))
{
// ldc.i4.0 / ret
methodData = new byte[] { 0x16, 0x2A };
}
else
{
tokenToNativeMethod[methodToken] = methodData;
// ldc.i4 0xDEADCODE / conv.u4 / throw
methodData = new byte[] { 0x20, 0xDE, 0xC0, 0xAD, 0xDE, 0x6D, 0x7A };
}
}
var dm = new DumpedMethod();
peImage.ReadMethodTableRowTo(dm, MDToken.ToRID(methodToken));
dm.code = methodData;
var codeReader = peImage.Reader;
codeReader.Position = peImage.RvaToOffset(dm.mdRVA);
byte[] code;
var mbHeader = MethodBodyParser.ParseMethodBody(codeReader, out code, out dm.extraSections);
peImage.UpdateMethodHeaderInfo(dm, mbHeader);
dumpedMethods.Add(dm);
}
}
return(true);
}