static void patchDwords(PE.PeImage peImage, BinaryReader reader, int count)
{
for (int i = 0; i < count; i++) {
uint rva = reader.ReadUInt32();
uint data = reader.ReadUInt32();
peImage.dotNetSafeWrite(rva, BitConverter.GetBytes(data));
}
}
public bool decrypt(PE.PeImage peImage, ISimpleDeobfuscator simpleDeobfuscator, ref Dictionary<uint, DumpedMethod> dumpedMethods)
{
if (encryptedResource.Method == null)
return false;
encryptedResource.init(simpleDeobfuscator);
if (!encryptedResource.FoundResource)
return false;
var methodsData = encryptedResource.decrypt();
bool hooksJitter = findDnrCompileMethod(encryptedResource.Method.DeclaringType) != null;
long xorKey = getXorKey();
if (xorKey != 0) {
// DNR 4.3, 4.4
var stream = new MemoryStream(methodsData);
var reader = new BinaryReader(stream);
var writer = new BinaryWriter(stream);
int count = methodsData.Length / 8;
for (int i = 0; i < count; i++) {
long val = reader.ReadInt64();
val ^= xorKey;
stream.Position -= 8;
writer.Write(val);
}
}
var methodsDataReader = new BinaryReader(new MemoryStream(methodsData));
int patchCount = methodsDataReader.ReadInt32();
int mode = methodsDataReader.ReadInt32();
int tmp = methodsDataReader.ReadInt32();
methodsDataReader.BaseStream.Position -= 4;
if ((tmp & 0xFF000000) == 0x06000000) {
// It's method token + rva. DNR 3.7.0.3 (and earlier?) - 3.9.0.1
methodsDataReader.BaseStream.Position += 8L * patchCount;
patchCount = methodsDataReader.ReadInt32();
mode = methodsDataReader.ReadInt32();
patchDwords(peImage, methodsDataReader, patchCount);
while (methodsDataReader.BaseStream.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, 4.1, 4.2, 4.3, 4.4
patchDwords(peImage, methodsDataReader, patchCount);
while (methodsDataReader.BaseStream.Position < methodsData.Length - 1) {
uint rva = methodsDataReader.ReadUInt32();
uint token = methodsDataReader.ReadUInt32(); // token, unknown, or index
int size = methodsDataReader.ReadInt32();
if (size > 0)
peImage.dotNetSafeWrite(rva, methodsDataReader.ReadBytes(size));
}
}
else {
// DNR 4.0 - 4.4 (jitter is hooked)
var metadataTables = peImage.Cor20Header.createMetadataTables();
var methodDef = metadataTables.getMetadataType(PE.MetadataIndex.iMethodDef);
var rvaToIndex = new Dictionary<uint, int>((int)methodDef.rows);
uint offset = methodDef.fileOffset;
for (int i = 0; i < methodDef.rows; i++) {
uint rva = peImage.offsetReadUInt32(offset);
offset += methodDef.totalSize;
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 Dictionary<uint, DumpedMethod>();
bool foundNativeCode = false;
while (methodsDataReader.BaseStream.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)) {
Log.w("Could not find method having code RVA {0:X8}", rva);
continue;
}
if (isNativeCode) {
if (!foundNativeCode) {
foundNativeCode = true;
Log.w("Found native code. Assembly won't run.");
}
//TODO: Convert to CIL code
Log.v("Found native code. Ignoring it for now... Assembly won't run. token: {0:X8}", 0x06000001 + methodIndex);
// Convert return true / false methods. The others are converted to
// throw 0xDEADCODE.
if (isCode(nativeLdci4, methodData)) {
uint val = BitConverter.ToUInt32(methodData, 4);
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 (isCode(nativeLdci4_0, methodData)) {
methodData = new byte[] { 0x16, 0x2A };
}
else
methodData = new byte[] { 0x20, 0xDE, 0xC0, 0xAD, 0xDE, 0x7A };
}
var dm = new DumpedMethod();
dm.token = (uint)(0x06000001 + methodIndex);
dm.code = methodData;
offset = methodDef.fileOffset + (uint)(methodIndex * methodDef.totalSize);
rva = peImage.offsetReadUInt32(offset);
dm.mdImplFlags = peImage.offsetReadUInt16(offset + (uint)methodDef.fields[1].offset);
dm.mdFlags = peImage.offsetReadUInt16(offset + (uint)methodDef.fields[2].offset);
dm.mdName = peImage.offsetRead(offset + (uint)methodDef.fields[3].offset, methodDef.fields[3].size);
dm.mdSignature = peImage.offsetRead(offset + (uint)methodDef.fields[4].offset, methodDef.fields[4].size);
dm.mdParamList = peImage.offsetRead(offset + (uint)methodDef.fields[5].offset, methodDef.fields[5].size);
if ((peImage.readByte(rva) & 3) == 2) {
dm.mhFlags = 2;
dm.mhMaxStack = 8;
dm.mhCodeSize = (uint)dm.code.Length;
dm.mhLocalVarSigTok = 0;
}
else {
dm.mhFlags = peImage.readUInt16(rva);
dm.mhMaxStack = peImage.readUInt16(rva + 2);
dm.mhCodeSize = (uint)dm.code.Length;
dm.mhLocalVarSigTok = peImage.readUInt32(rva + 8);
}
dumpedMethods[dm.token] = dm;
}
}
return true;
}
