69 lines
2.0 KiB
C#
69 lines
2.0 KiB
C#
/*
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Copyright (C) 2011-2012 de4dot@gmail.com
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This file is part of de4dot.
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de4dot is free software: you can redistribute it and/or modify
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it under the terms of the GNU General Public License as published by
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the Free Software Foundation, either version 3 of the License, or
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(at your option) any later version.
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de4dot is distributed in the hope that it will be useful,
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but WITHOUT ANY WARRANTY; without even the implied warranty of
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MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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GNU General Public License for more details.
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You should have received a copy of the GNU General Public License
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along with de4dot. If not, see <http://www.gnu.org/licenses/>.
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*/
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using System.Collections.Generic;
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using Mono.Cecil.Cil;
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using de4dot.blocks;
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using de4dot.blocks.cflow;
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namespace de4dot.code.deobfuscators.Confuser {
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class ConstantsFolder : BlockDeobfuscator {
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protected override bool deobfuscate(Block block) {
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bool modified = false;
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var instrs = block.Instructions;
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var constantsReader = createConstantsReader(instrs);
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for (int i = 0; i < instrs.Count; i++) {
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int index = 0;
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Instruction newInstr = null;
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var instr = instrs[i];
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if (constantsReader.isLoadConstant32(instr.Instruction)) {
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index = i;
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int val;
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if (!constantsReader.getInt32(ref index, out val))
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continue;
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newInstr = DotNetUtils.createLdci4(val);
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}
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else if (constantsReader.isLoadConstant64(instr.Instruction)) {
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index = i;
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long val;
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if (!constantsReader.getInt64(ref index, out val))
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continue;
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newInstr = Instruction.Create(OpCodes.Ldc_I8, val);
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}
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if (newInstr == null || index - i <= 1)
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continue;
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block.insert(index++, Instruction.Create(OpCodes.Pop));
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block.insert(index++, newInstr);
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i = index - 1;
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constantsReader = createConstantsReader(instrs);
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modified = true;
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}
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return modified;
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}
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static ConstantsReader createConstantsReader(IList<Instr> instrs) {
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return new ConstantsReader(instrs, false);
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}
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}
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}
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