DumpedMethods decryptMethods()
{
var dumpedMethods = new DumpedMethods();
var peImage = decrypterInfo.peImage;
var methodInfos = new MethodInfos(decrypterInfo.mainType, peImage, decrypterInfo.peHeader, decrypterInfo.mcKey);
methodInfos.initializeInfos();
var methodDef = peImage.DotNetFile.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;
}
public bool decrypt(MyPEImage peImage, ref DumpedMethods dumpedMethods)
{
dumpedMethods = new DumpedMethods();
bool decrypted = false;
var methodDef = peImage.DotNetFile.MetaData.TablesStream.MethodTable;
for (uint rid = 1; rid <= methodDef.Rows; rid++) {
var dm = new DumpedMethod();
peImage.readMethodTableRowTo(dm, rid);
if (dm.mdRVA == 0)
continue;
uint bodyOffset = peImage.rvaToOffset(dm.mdRVA);
peImage.Reader.Position = bodyOffset;
var mbHeader = MethodBodyParser.parseMethodBody(peImage.Reader, out dm.code, out dm.extraSections);
peImage.updateMethodHeaderInfo(dm, mbHeader);
if (dm.code.Length < 6 || dm.code[0] != 0x2A || dm.code[1] != 0x2A)
continue;
int seed = BitConverter.ToInt32(dm.code, 2);
Array.Copy(newCodeHeader, dm.code, newCodeHeader.Length);
if (seed == 0)
decrypt(dm.code);
else
decrypt(dm.code, seed);
dumpedMethods.add(dm);
decrypted = true;
}
return decrypted;
}
DumpedMethods createDumpedMethods(MyPEImage peImage, byte[] fileData, byte[] methodsData)
{
var dumpedMethods = new DumpedMethods();
var methodsDataReader = MemoryImageStream.Create(methodsData);
var fileDataReader = MemoryImageStream.Create(fileData);
var methodDef = peImage.DotNetFile.MetaData.TablesStream.MethodTable;
for (uint rid = 1; rid <= methodDef.Rows; rid++) {
var dm = new DumpedMethod();
peImage.readMethodTableRowTo(dm, rid);
if (dm.mdRVA == 0)
continue;
uint bodyOffset = peImage.rvaToOffset(dm.mdRVA);
byte b = peImage.offsetReadByte(bodyOffset);
uint codeOffset;
if ((b & 3) == 2) {
if (b != 2)
continue; // not zero byte code size
dm.mhFlags = 2;
dm.mhMaxStack = 8;
dm.mhLocalVarSigTok = 0;
codeOffset = bodyOffset + 1;
}
else {
if (peImage.offsetReadUInt32(bodyOffset + 4) != 0)
continue; // not zero byte code size
dm.mhFlags = peImage.offsetReadUInt16(bodyOffset);
dm.mhMaxStack = peImage.offsetReadUInt16(bodyOffset + 2);
dm.mhLocalVarSigTok = peImage.offsetReadUInt32(bodyOffset + 8);
codeOffset = bodyOffset + (uint)(dm.mhFlags >> 12) * 4;
}
fileDataReader.Position = codeOffset;
if (!decrypter.decrypt(fileDataReader, dm))
continue;
dumpedMethods.add(dm);
}
return dumpedMethods;
}
public bool decrypt(MyPEImage peImage, ISimpleDeobfuscator simpleDeobfuscator, ref DumpedMethods dumpedMethods, Dictionary<uint, byte[]> tokenToNativeCode, bool unpackedNativeFile)
{
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;
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, 4.1, 4.2, 4.3, 4.4
// If it's .NET 1.x, then offsets are used, not RVAs.
bool useOffsets = unpackedNativeFile && module.IsClr1x;
patchDwords(peImage, methodsDataReader, patchCount);
while (methodsDataReader.Position < methodsData.Length - 1) {
uint rva = methodsDataReader.ReadUInt32();
uint token = methodsDataReader.ReadUInt32(); // token, unknown, or index
int size = methodsDataReader.ReadInt32();
if (size > 0) {
var newData = methodsDataReader.ReadBytes(size);
if (useOffsets)
peImage.dotNetSafeWriteOffset(rva, newData);
else
peImage.dotNetSafeWrite(rva, newData);
}
}
}
else {
// DNR 4.0 - 4.5 (jitter is hooked)
var methodDef = peImage.DotNetFile.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;
}
void decryptMethodsOld(MDTable methodDefTable, ref DumpedMethods dumpedMethods)
{
dumpedMethods = new DumpedMethods();
var decrypter = new Decrypter10(peImage, codeHeader.decryptionKey);
for (uint rid = 1; rid <= methodDefTable.Rows; rid++) {
var dm = new DumpedMethod();
var method = (MethodDef)module.ResolveMethod(rid);
if (method == null || method.DeclaringType == module.GlobalType)
continue;
peImage.readMethodTableRowTo(dm, rid);
if (dm.mdRVA == 0)
continue;
uint bodyOffset = peImage.rvaToOffset(dm.mdRVA);
var mbHeader = decrypter.decrypt(bodyOffset, out dm.code, out dm.extraSections);
peImage.updateMethodHeaderInfo(dm, mbHeader);
dumpedMethods.add(dm);
}
}
void decryptMethods(uint codeHeaderOffset, MDTable methodDefTable, ICsHeader csHeader, ref DumpedMethods dumpedMethods)
{
var methodInfos = csHeader.getMethodInfos(codeHeaderOffset);
csHeader.patchMethodTable(methodDefTable, methodInfos);
dumpedMethods = new DumpedMethods();
decrypter = csHeader.createDecrypter();
for (uint rid = 1; rid <= (uint)methodInfos.Count; rid++) {
var methodInfo = methodInfos[(int)rid - 1];
if (methodInfo.codeOffs == 0)
continue;
var dm = new DumpedMethod();
peImage.readMethodTableRowTo(dm, rid);
var mbHeader = decrypter.decrypt(methodInfo, out dm.code, out dm.extraSections);
peImage.updateMethodHeaderInfo(dm, mbHeader);
dumpedMethods.add(dm);
}
}
