protected override bool Deobfuscate(Block block)
{
this.block = block;
if (!block.LastInstr.IsConditionalBranch() && block.LastInstr.OpCode.Code != Code.Switch)
{
return(false);
}
instructionEmulator.Initialize(blocks, allBlocks[0] == block);
var instructions = block.Instructions;
if (instructions.Count == 0)
{
return(false);
}
try {
for (int i = 0; i < instructions.Count - 1; i++)
{
var instr = instructions[i].Instruction;
instructionEmulator.Emulate(instr);
}
}
catch (NullReferenceException) {
// Here if eg. invalid metadata token in a call instruction (operand is null)
return(false);
}
return(branchEmulator.Emulate(block.LastInstr.Instruction));
}
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;
}
try {
instructionEmulator.Emulate(instr.Instruction);
}
catch (NullReferenceException) {
// Here if eg. invalid metadata token in a call instruction (operand is null)
break;
}
}
return(modified);
}
// Switch deobfuscation when block uses stloc N, ldloc N to load switch constant
// blk1:
// ldc.i4 X
// br swblk
// swblk:
// stloc N
// ldloc N
// switch (......)
bool DeobfuscateStLdloc(IList <Block> switchTargets, Block switchFallThrough, Block block)
{
bool modified = false;
foreach (var source in new List <Block>(block.Sources))
{
if (!isBranchBlock(source))
{
continue;
}
instructionEmulator.Initialize(blocks, allBlocks[0] == source);
instructionEmulator.Emulate(source.Instructions);
var target = GetSwitchTarget(switchTargets, switchFallThrough, instructionEmulator.Pop());
if (target == null)
{
continue;
}
source.ReplaceLastNonBranchWithBranch(0, target);
source.Add(new Instr(OpCodes.Pop.ToInstruction()));
modified = true;
}
return(modified);
}
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);
}
