protected override bool Deobfuscate(Block block)
{
bool modified = false;
instructionEmulator.Initialize(Blocks, AllBlocks[0] == block);
var instrs = block.Instructions;
for (int i = 0; i < instrs.Count; i++)
{
var instr = instrs[i];
switch (instr.OpCode.Code)
{
case Code.Ldarg:
case Code.Ldarg_0:
case Code.Ldarg_1:
case Code.Ldarg_2:
case Code.Ldarg_3:
case Code.Ldarg_S:
modified |= FixLoadInstruction(block, i, instructionEmulator.GetArg(instr.Instruction.GetParameter(args)));
break;
case Code.Ldloc:
case Code.Ldloc_0:
case Code.Ldloc_1:
case Code.Ldloc_2:
case Code.Ldloc_3:
case Code.Ldloc_S:
modified |= FixLoadInstruction(block, i, instructionEmulator.GetLocal(instr.Instruction.GetLocal(Blocks.Locals)));
break;
case Code.Ldarga:
case Code.Ldarga_S:
instructionEmulator.MakeArgUnknown((Parameter)instr.Operand);
break;
case Code.Ldloca:
case Code.Ldloca_S:
instructionEmulator.MakeLocalUnknown((Local)instr.Operand);
break;
case Code.Add:
case Code.Add_Ovf:
case Code.Add_Ovf_Un:
case Code.And:
case Code.Ceq:
case Code.Cgt:
case Code.Cgt_Un:
case Code.Clt:
case Code.Clt_Un:
case Code.Conv_I:
case Code.Conv_I1:
case Code.Conv_I2:
case Code.Conv_I4:
case Code.Conv_I8:
case Code.Conv_Ovf_I:
case Code.Conv_Ovf_I_Un:
case Code.Conv_Ovf_I1:
case Code.Conv_Ovf_I1_Un:
case Code.Conv_Ovf_I2:
case Code.Conv_Ovf_I2_Un:
case Code.Conv_Ovf_I4:
case Code.Conv_Ovf_I4_Un:
case Code.Conv_Ovf_I8:
case Code.Conv_Ovf_I8_Un:
case Code.Conv_Ovf_U:
case Code.Conv_Ovf_U_Un:
case Code.Conv_Ovf_U1:
case Code.Conv_Ovf_U1_Un:
case Code.Conv_Ovf_U2:
case Code.Conv_Ovf_U2_Un:
case Code.Conv_Ovf_U4:
case Code.Conv_Ovf_U4_Un:
case Code.Conv_Ovf_U8:
case Code.Conv_Ovf_U8_Un:
case Code.Conv_R_Un:
case Code.Conv_R4:
case Code.Conv_R8:
case Code.Conv_U:
case Code.Conv_U1:
case Code.Conv_U2:
case Code.Conv_U4:
case Code.Conv_U8:
case Code.Div:
case Code.Div_Un:
case Code.Dup:
case Code.Mul:
case Code.Mul_Ovf:
case Code.Mul_Ovf_Un:
case Code.Neg:
case Code.Not:
case Code.Or:
case Code.Rem:
case Code.Rem_Un:
case Code.Shl:
case Code.Shr:
case Code.Shr_Un:
case Code.Sub:
case Code.Sub_Ovf:
case Code.Sub_Ovf_Un:
case Code.Xor:
if (DisableNewCode)
{
break;
}
if (i + 1 < instrs.Count && instrs[i + 1].OpCode.Code == Code.Pop)
{
break;
}
if (!VerifyValidArgs(instr.Instruction))
{
break;
}
instructionEmulator.Emulate(instr.Instruction);
var tos = instructionEmulator.Peek();
Instruction newInstr = null;
if (tos.IsInt32())
{
var val = (Int32Value)tos;
if (val.AllBitsValid())
{
newInstr = Instruction.CreateLdcI4(val.Value);
}
}
else if (tos.IsInt64())
{
var val = (Int64Value)tos;
if (val.AllBitsValid())
{
newInstr = OpCodes.Ldc_I8.ToInstruction(val.Value);
}
}
else if (tos.IsReal8())
{
var val = (Real8Value)tos;
if (val.IsValid)
{
newInstr = GetLoadRealInstruction(val.Value);
}
}
if (newInstr != null)
{
block.Insert(i + 1, Instruction.Create(OpCodes.Pop));
block.Insert(i + 2, newInstr);
i += 2;
modified = true;
}
continue;
}
try {
instructionEmulator.Emulate(instr.Instruction);
}
catch (NullReferenceException) {
// Here if eg. invalid metadata token in a call instruction (operand is null)
break;
}
}
return(modified);
}
public static Value[] GetInitializedArray(int arraySize, MethodDef method, ref int newarrIndex, Code stelemOpCode) {
var resultValueArray = new Value[arraySize];
var emulator = new InstructionEmulator(method);
var theArray = new UnknownValue();
emulator.Push(theArray);
var instructions = method.Body.Instructions;
int i;
for (i = newarrIndex + 1; i < instructions.Count; i++) {
var instr = instructions[i];
if (instr.OpCode.FlowControl != FlowControl.Next)
break;
if (instr.OpCode.Code == Code.Newarr)
break;
switch (instr.OpCode.Code) {
case Code.Newarr:
case Code.Newobj:
goto done;
case Code.Stloc:
case Code.Stloc_S:
case Code.Stloc_0:
case Code.Stloc_1:
case Code.Stloc_2:
case Code.Stloc_3:
case Code.Starg:
case Code.Starg_S:
case Code.Stsfld:
case Code.Stfld:
if (emulator.Peek() == theArray && i != newarrIndex + 1 && i != newarrIndex + 2)
goto done;
break;
}
if (instr.OpCode.Code == stelemOpCode) {
var value = emulator.Pop();
var index = emulator.Pop() as Int32Value;
var array = emulator.Pop();
if (ReferenceEquals(array, theArray) && index != null && index.AllBitsValid()) {
if (0 <= index.Value && index.Value < resultValueArray.Length)
resultValueArray[index.Value] = value;
}
}
else
emulator.Emulate(instr);
}
done:
if (i != newarrIndex + 1)
i--;
newarrIndex = i;
return resultValueArray;
}
