/// <summary>
/// Makes random conditional jump instruction + links basic blocks and sets RefVars
/// </summary>
/// <param name="nop">NoOperation instruction (will be made into ConditionalJump)</param>
/// <param name="condition">Type of condition</param>
/// <param name="target">Target basic block the control flow is transfered to, if the relation holds true.</param>
public static void RandomConditionalJump(Instruction nop, Instruction.ConditionType condition, BasicBlock target)
{
if (nop.statementType != Objects.Common.StatementType.NoOperation && nop.statementType != Objects.Common.StatementType.UnconditionalJump)
{
throw new ObfuscatorException("Only NoOperation and UnconditionalJump instructions can be modified to ConditionalJump!");
}
if (nop.parent == null || nop.parent.parent == null)
{
throw new ObfuscatorException("Instruction -> basic block -> function parent link is broken.");
}
if (nop.parent.parent != target.parent)
{
throw new ObfuscatorException("The instruction and the basic block should be contained in the same function.");
}
Variable var = FakeParameters.GetRandom(nop.parent.parent);
if (var.fixedMax.HasValue && var.fixedMax.Value > Common.GlobalMaxValue)
{
throw new ObfuscatorException("The fixedMax value is greated then the globally accepted maximum.");
}
if (var.fixedMin.HasValue && var.fixedMin.Value < Common.GlobalMinValue)
{
throw new ObfuscatorException("The fixedMin value is smaller then the globally accepted minimum.");
}
int right_value = 0;
Instruction.RelationalOperationType relop = Instruction.RelationalOperationType.Equals;
bool use_min_limit = false;
// Here we chose to use a FixedMin or FixedMax for logical relation
if (var.fixedMin.HasValue && var.fixedMax.HasValue)
{
use_min_limit = (bool)Randomizer.OneFromMany(true, false);
}
else if (var.fixedMin.HasValue)
{
use_min_limit = true;
}
if (use_min_limit) // FixedMin will be used
{
right_value = Randomizer.OneFromSectionWithDescendingProbability(var.fixedMin.Value, Common.GlobalMinValue + Common.LoopConditionalJumpMaxRange);
switch (condition)
{
case Instruction.ConditionType.AlwaysTrue:
relop = (Instruction.RelationalOperationType)Randomizer.OneFromMany(Instruction.RelationalOperationType.Greater,
Instruction.RelationalOperationType.GreaterOrEquals);
break;
case Instruction.ConditionType.AlwaysFalse:
relop = (Instruction.RelationalOperationType)Randomizer.OneFromMany(Instruction.RelationalOperationType.Smaller,
Instruction.RelationalOperationType.SmallerOrEquals);
break;
case Instruction.ConditionType.Random:
relop = (Instruction.RelationalOperationType)Randomizer.OneFromMany(Instruction.RelationalOperationType.Smaller,
Instruction.RelationalOperationType.SmallerOrEquals,
Instruction.RelationalOperationType.Greater,
Instruction.RelationalOperationType.GreaterOrEquals);
break;
default:
throw new ObfuscatorException("Unrecognized condition type.");
}
}
if (!use_min_limit) // FixedMax will be used
{
right_value = Randomizer.OneFromSectionWithDescendingProbability(var.fixedMax.Value, Common.GlobalMaxValue - Common.LoopConditionalJumpMaxRange);
switch (condition)
{
case Instruction.ConditionType.AlwaysTrue:
relop = (Instruction.RelationalOperationType)Randomizer.OneFromMany(Instruction.RelationalOperationType.Smaller,
Instruction.RelationalOperationType.SmallerOrEquals);
break;
case Instruction.ConditionType.AlwaysFalse:
relop = (Instruction.RelationalOperationType)Randomizer.OneFromMany(Instruction.RelationalOperationType.Greater,
Instruction.RelationalOperationType.GreaterOrEquals);
break;
case Instruction.ConditionType.Random:
relop = (Instruction.RelationalOperationType)Randomizer.OneFromMany(Instruction.RelationalOperationType.Smaller,
Instruction.RelationalOperationType.SmallerOrEquals,
Instruction.RelationalOperationType.Greater,
Instruction.RelationalOperationType.GreaterOrEquals);
break;
default:
throw new ObfuscatorException("Unrecognized condition type.");
}
}
MakeInstruction.ConditionalJump(nop, var, right_value, relop, target);
}
private static void Obfuscation(Routine routine)
{
Logging.WriteComplexityMetrics(routine, "Original");
//Checking whether the functions have either "division" or "modulo" operations
//If they do, fake instructions with original variables should be inserted only before the return
//to avoid problems with the these operations
foreach (Function func in routine.Functions)
{
func.CheckDivisionModulo();
}
//Creating fake input parameters in all functions
FakeParameters.CreateFakeParameters(routine);
//Checking for Multiple Obfuscation
for (int i = 0; i < Convert.ToInt32(ConfigurationManager.AppSettings["MultipleRuns"]); i++)
{
//Creating fake variables
foreach (Function func in routine.Functions)
{
for (int j = 0; j < (Common.PercentageFakeVars * func.LocalVariables.FindAll(x => !x.fake).Count) / 100; j++)
{
func.LocalVariables.Add(new Variable(Variable.Kind.Local, Variable.Purpose.Fake, Objects.Common.MemoryRegionSize.Integer));
}
}
if (ConfigurationManager.AppSettings["ConstCoverAlgInMultipleRuns"].Split('-')[i].Equals("1"))
{
Console.Write("Step 1: Constants coverage");
ConstCoverage.CoverConstants(routine);
routine.Validate();
PrintSuccess();
Logging.WriteReadableTAC(routine, "CONST");
Logging.DrawCFG(routine, "CONST");
}
if (ConfigurationManager.AppSettings["UncMeshingAlgInMultipleRuns"].Split('-')[i].Equals("1"))
{
Console.Write("Step 2: Meshing unconditional jumps");
Meshing.MeshUnconditionals(routine);
routine.Validate();
PrintSuccess();
Logging.WriteReadableTAC(routine, "MeshingUNC");
Logging.DrawCFG(routine, "MeshingUNC");
}
if (ConfigurationManager.AppSettings["CondMeshingAlgInMultipleRuns"].Split('-')[i].Equals("1"))
{
Console.Write("Step 3: Meshing conditional jumps");
Meshing.MeshConditionals(routine);
routine.Validate();
PrintSuccess();
Logging.WriteReadableTAC(routine, "MeshingCOND");
Logging.DrawCFG(routine, "MeshingCOND");
}
Console.Write("Step 4: Generation of fake NOP instructions");
foreach (Function func in routine.Functions)
{
FakeCode.GenerateNoOperations(func);
}
routine.Validate();
PrintSuccess();
Logging.WriteRoutine(routine, "NoOpersGeneration");
Logging.WriteReadableTAC(routine, "FakeNOPs");
Console.Write("Step 5: Partial data analysis");
DataAnalysis.GatherBasicBlockInfo(routine);
PrintSuccess();
if (ConfigurationManager.AppSettings["FakeJumpsAlgInMultipleRuns"].Split('-')[i].Equals("1"))
{
Console.Write("Step 6: Generation of fake conditional jumps from NOPs");
foreach (Function func in routine.Functions)
{
FakeCode.GenerateConditionalJumps(func);
}
Logging.WriteRoutine(routine, "CondJumps");
foreach (Function func in routine.Functions)
{
FakeCode.GenerateNoOperations(func);
}
routine.Validate();
PrintSuccess();
}
Console.Write("Step 7: Complete data analysis");
foreach (Function func in routine.Functions)
{
DataAnalysis.DeadVarsAlgortihm(func);
}
DataAnalysis.GatherBasicBlockInfo(routine);
PrintSuccess();
Console.Write("Step 8: Generation of fake instructions from NOPs");
foreach (Function func in routine.Functions)
{
FakeCode.GenerateFakeInstructions(func);
}
Logging.WriteRoutine(routine, "FakeIns");
Logging.DrawCFG(routine, "CondJumps");
Logging.WriteComplexityMetrics(routine, "Final");
FakeCode.CheckForProblems(routine);
routine.Validate();
PrintSuccess();
Logging.WriteReadableTAC(routine, "FakeInstrFromNOPs");
}
}
