2011-10-17 06:22:22 +08:00
|
|
|
|
/*
|
|
|
|
|
Copyright (C) 2011 de4dot@gmail.com
|
|
|
|
|
|
|
|
|
|
This file is part of de4dot.
|
|
|
|
|
|
|
|
|
|
de4dot is free software: you can redistribute it and/or modify
|
|
|
|
|
it under the terms of the GNU General Public License as published by
|
|
|
|
|
the Free Software Foundation, either version 3 of the License, or
|
|
|
|
|
(at your option) any later version.
|
|
|
|
|
|
|
|
|
|
de4dot is distributed in the hope that it will be useful,
|
|
|
|
|
but WITHOUT ANY WARRANTY; without even the implied warranty of
|
|
|
|
|
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
|
|
|
|
|
GNU General Public License for more details.
|
|
|
|
|
|
|
|
|
|
You should have received a copy of the GNU General Public License
|
|
|
|
|
along with de4dot. If not, see <http://www.gnu.org/licenses/>.
|
|
|
|
|
*/
|
|
|
|
|
|
|
|
|
|
using System.Collections.Generic;
|
|
|
|
|
using Mono.Cecil;
|
|
|
|
|
using Mono.Cecil.Cil;
|
|
|
|
|
|
|
|
|
|
namespace de4dot.blocks.cflow {
|
2011-10-19 05:31:50 +08:00
|
|
|
|
class BlockCflowDeobfuscator {
|
2011-10-22 03:47:06 +08:00
|
|
|
|
Blocks blocks;
|
2011-10-17 06:22:22 +08:00
|
|
|
|
Block block;
|
|
|
|
|
InstructionEmulator instructionEmulator = new InstructionEmulator();
|
|
|
|
|
|
2011-10-22 01:32:37 +08:00
|
|
|
|
public void init(Blocks blocks, Block block) {
|
2011-10-22 03:47:06 +08:00
|
|
|
|
this.blocks = blocks;
|
2011-10-17 06:22:22 +08:00
|
|
|
|
this.block = block;
|
2011-10-22 01:32:37 +08:00
|
|
|
|
instructionEmulator.init(blocks.Method.HasThis, false, blocks.Method.Parameters, blocks.Locals);
|
2011-10-17 06:22:22 +08:00
|
|
|
|
}
|
|
|
|
|
|
|
|
|
|
// Returns true if code was updated, false otherwise
|
|
|
|
|
public bool deobfuscate() {
|
|
|
|
|
var instructions = block.Instructions;
|
|
|
|
|
if (instructions.Count == 0)
|
|
|
|
|
return false;
|
2011-10-27 21:57:33 +08:00
|
|
|
|
try {
|
|
|
|
|
for (int i = 0; i < instructions.Count - 1; i++) {
|
|
|
|
|
var instr = instructions[i].Instruction;
|
|
|
|
|
instructionEmulator.emulate(instr);
|
|
|
|
|
}
|
|
|
|
|
}
|
|
|
|
|
catch (System.NullReferenceException) {
|
|
|
|
|
// Here if eg. invalid metadata token in a call instruction (operand is null)
|
|
|
|
|
return false;
|
2011-10-17 06:22:22 +08:00
|
|
|
|
}
|
|
|
|
|
|
|
|
|
|
switch (block.LastInstr.OpCode.Code) {
|
|
|
|
|
case Code.Beq:
|
|
|
|
|
case Code.Beq_S: return emulate_Beq();
|
|
|
|
|
case Code.Bge:
|
|
|
|
|
case Code.Bge_S: return emulate_Bge();
|
|
|
|
|
case Code.Bge_Un:
|
|
|
|
|
case Code.Bge_Un_S: return emulate_Bge_Un();
|
|
|
|
|
case Code.Bgt:
|
|
|
|
|
case Code.Bgt_S: return emulate_Bgt();
|
|
|
|
|
case Code.Bgt_Un:
|
|
|
|
|
case Code.Bgt_Un_S: return emulate_Bgt_Un();
|
|
|
|
|
case Code.Ble:
|
|
|
|
|
case Code.Ble_S: return emulate_Ble();
|
|
|
|
|
case Code.Ble_Un:
|
|
|
|
|
case Code.Ble_Un_S: return emulate_Ble_Un();
|
|
|
|
|
case Code.Blt:
|
|
|
|
|
case Code.Blt_S: return emulate_Blt();
|
|
|
|
|
case Code.Blt_Un:
|
|
|
|
|
case Code.Blt_Un_S: return emulate_Blt_Un();
|
|
|
|
|
case Code.Bne_Un:
|
|
|
|
|
case Code.Bne_Un_S: return emulate_Bne_Un();
|
|
|
|
|
case Code.Brfalse:
|
|
|
|
|
case Code.Brfalse_S:return emulate_Brfalse();
|
|
|
|
|
case Code.Brtrue:
|
|
|
|
|
case Code.Brtrue_S: return emulate_Brtrue();
|
2011-10-18 14:17:21 +08:00
|
|
|
|
case Code.Switch: return emulate_Switch();
|
2011-10-17 06:22:22 +08:00
|
|
|
|
|
|
|
|
|
default:
|
|
|
|
|
return false;
|
|
|
|
|
}
|
|
|
|
|
}
|
|
|
|
|
|
2011-10-17 13:28:53 +08:00
|
|
|
|
bool emulateBranch(int stackArgs, Bool3 cond) {
|
|
|
|
|
if (cond == Bool3.Unknown)
|
|
|
|
|
return false;
|
|
|
|
|
return emulateBranch(stackArgs, cond == Bool3.True);
|
|
|
|
|
}
|
|
|
|
|
|
2011-10-17 06:22:22 +08:00
|
|
|
|
bool emulateBranch(int stackArgs, bool isTaken) {
|
2011-10-18 14:17:21 +08:00
|
|
|
|
popPushedArgs(stackArgs);
|
|
|
|
|
block.replaceBccWithBranch(isTaken);
|
|
|
|
|
return true;
|
|
|
|
|
}
|
|
|
|
|
|
|
|
|
|
void popPushedArgs(int stackArgs) {
|
2011-10-17 06:22:22 +08:00
|
|
|
|
// Pop the arguments to the bcc instruction. The dead code remover will get rid of the
|
|
|
|
|
// pop and any pushed arguments. Insert the pops just before the bcc instr.
|
|
|
|
|
for (int i = 0; i < stackArgs; i++)
|
|
|
|
|
block.insert(block.Instructions.Count - 1, Instruction.Create(OpCodes.Pop));
|
|
|
|
|
}
|
|
|
|
|
|
|
|
|
|
bool emulate_Beq() {
|
|
|
|
|
var val2 = instructionEmulator.pop();
|
|
|
|
|
var val1 = instructionEmulator.pop();
|
|
|
|
|
|
2011-10-19 05:31:50 +08:00
|
|
|
|
if (val1.isInt32() && val2.isInt32())
|
2011-10-17 13:28:53 +08:00
|
|
|
|
return emulateBranch(2, Int32Value.compareEq((Int32Value)val1, (Int32Value)val2));
|
2011-10-19 05:31:50 +08:00
|
|
|
|
else if (val1.isInt64() && val2.isInt64())
|
2011-10-17 13:28:53 +08:00
|
|
|
|
return emulateBranch(2, Int64Value.compareEq((Int64Value)val1, (Int64Value)val2));
|
2011-10-19 05:31:50 +08:00
|
|
|
|
else if (val1.isNull() && val2.isNull())
|
2011-10-17 06:22:22 +08:00
|
|
|
|
return emulateBranch(2, true);
|
2011-10-17 13:28:53 +08:00
|
|
|
|
else
|
2011-10-17 06:22:22 +08:00
|
|
|
|
return false;
|
|
|
|
|
}
|
|
|
|
|
|
|
|
|
|
bool emulate_Bne_Un() {
|
|
|
|
|
var val2 = instructionEmulator.pop();
|
|
|
|
|
var val1 = instructionEmulator.pop();
|
|
|
|
|
|
2011-10-19 05:31:50 +08:00
|
|
|
|
if (val1.isInt32() && val2.isInt32())
|
2011-10-17 13:28:53 +08:00
|
|
|
|
return emulateBranch(2, Int32Value.compareNeq((Int32Value)val1, (Int32Value)val2));
|
2011-10-19 05:31:50 +08:00
|
|
|
|
else if (val1.isInt64() && val2.isInt64())
|
2011-10-17 13:28:53 +08:00
|
|
|
|
return emulateBranch(2, Int64Value.compareNeq((Int64Value)val1, (Int64Value)val2));
|
2011-10-19 05:31:50 +08:00
|
|
|
|
else if (val1.isNull() && val2.isNull())
|
2011-10-17 06:22:22 +08:00
|
|
|
|
return emulateBranch(2, false);
|
2011-10-17 13:28:53 +08:00
|
|
|
|
else
|
2011-10-17 06:22:22 +08:00
|
|
|
|
return false;
|
|
|
|
|
}
|
|
|
|
|
|
|
|
|
|
bool emulate_Bge() {
|
|
|
|
|
var val2 = instructionEmulator.pop();
|
|
|
|
|
var val1 = instructionEmulator.pop();
|
|
|
|
|
|
2011-10-19 05:31:50 +08:00
|
|
|
|
if (val1.isInt32() && val2.isInt32())
|
2011-10-17 13:28:53 +08:00
|
|
|
|
return emulateBranch(2, Int32Value.compareGe((Int32Value)val1, (Int32Value)val2));
|
2011-10-19 05:31:50 +08:00
|
|
|
|
else if (val1.isInt64() && val2.isInt64())
|
2011-10-17 13:28:53 +08:00
|
|
|
|
return emulateBranch(2, Int64Value.compareGe((Int64Value)val1, (Int64Value)val2));
|
|
|
|
|
else
|
2011-10-17 06:22:22 +08:00
|
|
|
|
return false;
|
|
|
|
|
}
|
|
|
|
|
|
|
|
|
|
bool emulate_Bge_Un() {
|
|
|
|
|
var val2 = instructionEmulator.pop();
|
|
|
|
|
var val1 = instructionEmulator.pop();
|
|
|
|
|
|
2011-10-19 05:31:50 +08:00
|
|
|
|
if (val1.isInt32() && val2.isInt32())
|
2011-10-17 13:28:53 +08:00
|
|
|
|
return emulateBranch(2, Int32Value.compareGe_Un((Int32Value)val1, (Int32Value)val2));
|
2011-10-19 05:31:50 +08:00
|
|
|
|
else if (val1.isInt64() && val2.isInt64())
|
2011-10-17 13:28:53 +08:00
|
|
|
|
return emulateBranch(2, Int64Value.compareGe_Un((Int64Value)val1, (Int64Value)val2));
|
|
|
|
|
else
|
2011-10-17 06:22:22 +08:00
|
|
|
|
return false;
|
|
|
|
|
}
|
|
|
|
|
|
|
|
|
|
bool emulate_Bgt() {
|
|
|
|
|
var val2 = instructionEmulator.pop();
|
|
|
|
|
var val1 = instructionEmulator.pop();
|
|
|
|
|
|
2011-10-19 05:31:50 +08:00
|
|
|
|
if (val1.isInt32() && val2.isInt32())
|
2011-10-17 13:28:53 +08:00
|
|
|
|
return emulateBranch(2, Int32Value.compareGt((Int32Value)val1, (Int32Value)val2));
|
2011-10-19 05:31:50 +08:00
|
|
|
|
else if (val1.isInt64() && val2.isInt64())
|
2011-10-17 13:28:53 +08:00
|
|
|
|
return emulateBranch(2, Int64Value.compareGt((Int64Value)val1, (Int64Value)val2));
|
|
|
|
|
else
|
2011-10-17 06:22:22 +08:00
|
|
|
|
return false;
|
|
|
|
|
}
|
|
|
|
|
|
|
|
|
|
bool emulate_Bgt_Un() {
|
|
|
|
|
var val2 = instructionEmulator.pop();
|
|
|
|
|
var val1 = instructionEmulator.pop();
|
|
|
|
|
|
2011-10-19 05:31:50 +08:00
|
|
|
|
if (val1.isInt32() && val2.isInt32())
|
2011-10-17 13:28:53 +08:00
|
|
|
|
return emulateBranch(2, Int32Value.compareGt_Un((Int32Value)val1, (Int32Value)val2));
|
2011-10-19 05:31:50 +08:00
|
|
|
|
else if (val1.isInt64() && val2.isInt64())
|
2011-10-17 13:28:53 +08:00
|
|
|
|
return emulateBranch(2, Int64Value.compareGt_Un((Int64Value)val1, (Int64Value)val2));
|
|
|
|
|
else
|
2011-10-17 06:22:22 +08:00
|
|
|
|
return false;
|
|
|
|
|
}
|
|
|
|
|
|
|
|
|
|
bool emulate_Ble() {
|
|
|
|
|
var val2 = instructionEmulator.pop();
|
|
|
|
|
var val1 = instructionEmulator.pop();
|
|
|
|
|
|
2011-10-19 05:31:50 +08:00
|
|
|
|
if (val1.isInt32() && val2.isInt32())
|
2011-10-17 13:28:53 +08:00
|
|
|
|
return emulateBranch(2, Int32Value.compareLe((Int32Value)val1, (Int32Value)val2));
|
2011-10-19 05:31:50 +08:00
|
|
|
|
else if (val1.isInt64() && val2.isInt64())
|
2011-10-17 13:28:53 +08:00
|
|
|
|
return emulateBranch(2, Int64Value.compareLe((Int64Value)val1, (Int64Value)val2));
|
|
|
|
|
else
|
2011-10-17 06:22:22 +08:00
|
|
|
|
return false;
|
|
|
|
|
}
|
|
|
|
|
|
|
|
|
|
bool emulate_Ble_Un() {
|
|
|
|
|
var val2 = instructionEmulator.pop();
|
|
|
|
|
var val1 = instructionEmulator.pop();
|
|
|
|
|
|
2011-10-19 05:31:50 +08:00
|
|
|
|
if (val1.isInt32() && val2.isInt32())
|
2011-10-17 13:28:53 +08:00
|
|
|
|
return emulateBranch(2, Int32Value.compareLe_Un((Int32Value)val1, (Int32Value)val2));
|
2011-10-19 05:31:50 +08:00
|
|
|
|
else if (val1.isInt64() && val2.isInt64())
|
2011-10-17 13:28:53 +08:00
|
|
|
|
return emulateBranch(2, Int64Value.compareLe_Un((Int64Value)val1, (Int64Value)val2));
|
|
|
|
|
else
|
2011-10-17 06:22:22 +08:00
|
|
|
|
return false;
|
|
|
|
|
}
|
|
|
|
|
|
|
|
|
|
bool emulate_Blt() {
|
|
|
|
|
var val2 = instructionEmulator.pop();
|
|
|
|
|
var val1 = instructionEmulator.pop();
|
|
|
|
|
|
2011-10-19 05:31:50 +08:00
|
|
|
|
if (val1.isInt32() && val2.isInt32())
|
2011-10-17 13:28:53 +08:00
|
|
|
|
return emulateBranch(2, Int32Value.compareLt((Int32Value)val1, (Int32Value)val2));
|
2011-10-19 05:31:50 +08:00
|
|
|
|
else if (val1.isInt64() && val2.isInt64())
|
2011-10-17 13:28:53 +08:00
|
|
|
|
return emulateBranch(2, Int64Value.compareLt((Int64Value)val1, (Int64Value)val2));
|
|
|
|
|
else
|
2011-10-17 06:22:22 +08:00
|
|
|
|
return false;
|
|
|
|
|
}
|
|
|
|
|
|
|
|
|
|
bool emulate_Blt_Un() {
|
|
|
|
|
var val2 = instructionEmulator.pop();
|
|
|
|
|
var val1 = instructionEmulator.pop();
|
|
|
|
|
|
2011-10-19 05:31:50 +08:00
|
|
|
|
if (val1.isInt32() && val2.isInt32())
|
2011-10-17 13:28:53 +08:00
|
|
|
|
return emulateBranch(2, Int32Value.compareLt_Un((Int32Value)val1, (Int32Value)val2));
|
2011-10-19 05:31:50 +08:00
|
|
|
|
else if (val1.isInt64() && val2.isInt64())
|
2011-10-17 13:28:53 +08:00
|
|
|
|
return emulateBranch(2, Int64Value.compareLt_Un((Int64Value)val1, (Int64Value)val2));
|
|
|
|
|
else
|
2011-10-17 06:22:22 +08:00
|
|
|
|
return false;
|
|
|
|
|
}
|
|
|
|
|
|
|
|
|
|
bool emulate_Brfalse() {
|
|
|
|
|
var val1 = instructionEmulator.pop();
|
|
|
|
|
|
2011-10-19 05:31:50 +08:00
|
|
|
|
if (val1.isInt32())
|
2011-10-17 13:28:53 +08:00
|
|
|
|
return emulateBranch(1, Int32Value.compareFalse((Int32Value)val1));
|
2011-10-19 05:31:50 +08:00
|
|
|
|
else if (val1.isInt64())
|
2011-10-17 13:28:53 +08:00
|
|
|
|
return emulateBranch(1, Int64Value.compareFalse((Int64Value)val1));
|
2011-10-19 05:31:50 +08:00
|
|
|
|
else if (val1.isNull())
|
2011-10-17 06:22:22 +08:00
|
|
|
|
return emulateBranch(1, true);
|
|
|
|
|
else
|
|
|
|
|
return false;
|
|
|
|
|
}
|
|
|
|
|
|
|
|
|
|
bool emulate_Brtrue() {
|
|
|
|
|
var val1 = instructionEmulator.pop();
|
|
|
|
|
|
2011-10-19 05:31:50 +08:00
|
|
|
|
if (val1.isInt32())
|
2011-10-17 13:28:53 +08:00
|
|
|
|
return emulateBranch(1, Int32Value.compareTrue((Int32Value)val1));
|
2011-10-19 05:31:50 +08:00
|
|
|
|
else if (val1.isInt64())
|
2011-10-17 13:28:53 +08:00
|
|
|
|
return emulateBranch(1, Int64Value.compareTrue((Int64Value)val1));
|
2011-10-19 05:31:50 +08:00
|
|
|
|
else if (val1.isNull())
|
2011-10-17 06:22:22 +08:00
|
|
|
|
return emulateBranch(1, false);
|
|
|
|
|
else
|
|
|
|
|
return false;
|
|
|
|
|
}
|
2011-10-18 14:17:21 +08:00
|
|
|
|
|
|
|
|
|
bool emulate_Switch() {
|
|
|
|
|
var val1 = instructionEmulator.pop();
|
|
|
|
|
|
2011-10-19 05:31:50 +08:00
|
|
|
|
if (!val1.isInt32())
|
2011-10-18 14:17:21 +08:00
|
|
|
|
return false;
|
2011-10-19 05:31:50 +08:00
|
|
|
|
var target = CflowUtils.getSwitchTarget(block.Targets, block.FallThrough, (Int32Value)val1);
|
|
|
|
|
if (target == null)
|
2011-10-18 14:17:21 +08:00
|
|
|
|
return false;
|
|
|
|
|
|
|
|
|
|
popPushedArgs(1);
|
2011-10-19 05:31:50 +08:00
|
|
|
|
block.replaceSwitchWithBranch(target);
|
2011-10-18 14:17:21 +08:00
|
|
|
|
return true;
|
|
|
|
|
}
|
2011-10-17 06:22:22 +08:00
|
|
|
|
}
|
|
|
|
|
}
|