646 lines
23 KiB
C#
646 lines
23 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;
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using System.Collections.Generic;
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using System.IO;
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using dot10.DotNet;
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using de4dot.PE;
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using de4dot.blocks;
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namespace de4dot.code.deobfuscators.Agile_NET {
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class CodeHeader {
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public byte[] signature;
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public byte[] decryptionKey;
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public uint totalCodeSize;
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public uint numMethods;
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public uint methodDefTableOffset; // Relative to start of metadata
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public uint methodDefElemSize;
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}
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struct MethodInfo {
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public uint codeOffs, codeSize, flags, localVarSigTok;
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public MethodInfo(uint codeOffs, uint codeSize, uint flags, uint localVarSigTok) {
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this.codeOffs = codeOffs;
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this.codeSize = codeSize;
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this.flags = flags;
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this.localVarSigTok = localVarSigTok;
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}
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public override string ToString() {
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return string.Format("{0:X8} {1:X8} {2:X8} {3:X8}", codeOffs, codeSize, flags, localVarSigTok);
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}
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}
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class MethodsDecrypter {
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static readonly byte[] oldSignature = new byte[16] { 0x1F, 0x68, 0x9D, 0x2B, 0x07, 0x4A, 0xA6, 0x4A, 0x92, 0xBB, 0x31, 0x7E, 0x60, 0x7F, 0xD7, 0xCD };
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static readonly byte[] normalSignature = new byte[16] { 0x08, 0x44, 0x65, 0xE1, 0x8C, 0x82, 0x13, 0x4C, 0x9C, 0x85, 0xB4, 0x17, 0xDA, 0x51, 0xAD, 0x25 };
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static readonly byte[] proSignature = new byte[16] { 0x68, 0xA0, 0xBB, 0x60, 0x13, 0x65, 0x5F, 0x41, 0xAE, 0x42, 0xAB, 0x42, 0x9B, 0x6B, 0x4E, 0xC1 };
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enum SigType {
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Unknown,
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Old,
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Normal,
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Pro,
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}
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PeImage peImage;
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ModuleDefMD module;
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CliSecureRtType csRtType;
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CodeHeader codeHeader = new CodeHeader();
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IDecrypter decrypter;
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SigType sigType;
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interface IDecrypter {
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MethodBodyHeader decrypt(MethodInfo methodInfo, out byte[] code, out byte[] extraSections);
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}
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abstract class DecrypterBase : IDecrypter {
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protected readonly PeImage peImage;
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protected readonly CodeHeader codeHeader;
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protected readonly uint endOfMetadata;
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public DecrypterBase(PeImage peImage, CodeHeader codeHeader) {
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this.peImage = peImage;
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this.codeHeader = codeHeader;
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endOfMetadata = peImage.rvaToOffset(peImage.Cor20Header.metadataDirectory.virtualAddress + peImage.Cor20Header.metadataDirectory.size);
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}
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public abstract MethodBodyHeader decrypt(MethodInfo methodInfo, out byte[] code, out byte[] extraSections);
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protected MethodBodyHeader getCodeBytes(byte[] methodBody, out byte[] code, out byte[] extraSections) {
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return MethodBodyParser.parseMethodBody(new BinaryReader(new MemoryStream(methodBody)), out code, out extraSections);
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}
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}
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// CS 1.1 (could be other versions too)
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class Decrypter10 {
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PeImage peImage;
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CsBlowfish blowfish;
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public Decrypter10(PeImage peImage, byte[] key) {
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this.peImage = peImage;
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this.blowfish = new CsBlowfish(key);
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}
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public MethodBodyHeader decrypt(uint bodyOffset, out byte[] code, out byte[] extraSections) {
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peImage.Reader.BaseStream.Position = bodyOffset;
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var mbHeader = MethodBodyParser.parseMethodBody(peImage.Reader, out code, out extraSections);
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blowfish.decrypt(code);
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return mbHeader;
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}
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}
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// CS 3.0 (could be other versions too)
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class Decrypter30 : DecrypterBase {
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public Decrypter30(PeImage peImage, CodeHeader codeHeader)
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: base(peImage, codeHeader) {
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}
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public override MethodBodyHeader decrypt(MethodInfo methodInfo, out byte[] code, out byte[] extraSections) {
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peImage.Reader.BaseStream.Position = peImage.rvaToOffset(methodInfo.codeOffs);
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return MethodBodyParser.parseMethodBody(peImage.Reader, out code, out extraSections);
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}
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}
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// CS 4.0 (could be other versions too)
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class Decrypter40 : DecrypterBase {
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public Decrypter40(PeImage peImage, CodeHeader codeHeader)
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: base(peImage, codeHeader) {
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}
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public override MethodBodyHeader decrypt(MethodInfo methodInfo, out byte[] code, out byte[] extraSections) {
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peImage.Reader.BaseStream.Position = endOfMetadata + methodInfo.codeOffs;
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return MethodBodyParser.parseMethodBody(peImage.Reader, out code, out extraSections);
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}
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}
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// CS 4.5 (could be other versions too)
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class Decrypter45 : DecrypterBase {
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public Decrypter45(PeImage peImage, CodeHeader codeHeader)
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: base(peImage, codeHeader) {
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}
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public override MethodBodyHeader decrypt(MethodInfo methodInfo, out byte[] code, out byte[] extraSections) {
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var data = peImage.offsetReadBytes(endOfMetadata + methodInfo.codeOffs, (int)methodInfo.codeSize);
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for (int i = 0; i < data.Length; i++) {
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byte b = data[i];
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b ^= codeHeader.decryptionKey[(methodInfo.codeOffs - 0x28 + i) % 16];
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data[i] = b;
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}
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return getCodeBytes(data, out code, out extraSections);
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}
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}
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// CS 5.0+
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class Decrypter5 : DecrypterBase {
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readonly uint codeHeaderSize;
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public Decrypter5(PeImage peImage, CodeHeader codeHeader, uint codeHeaderSize)
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: base(peImage, codeHeader) {
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this.codeHeaderSize = codeHeaderSize;
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}
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public override MethodBodyHeader decrypt(MethodInfo methodInfo, out byte[] code, out byte[] extraSections) {
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byte[] data = peImage.offsetReadBytes(endOfMetadata + methodInfo.codeOffs, (int)methodInfo.codeSize);
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for (int i = 0; i < data.Length; i++) {
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byte b = data[i];
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b ^= codeHeader.decryptionKey[(methodInfo.codeOffs - codeHeaderSize + i) % 16];
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b ^= codeHeader.decryptionKey[(methodInfo.codeOffs - codeHeaderSize + i + 7) % 16];
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data[i] = b;
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}
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return getCodeBytes(data, out code, out extraSections);
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}
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}
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// CS 5.4+. Used when the anti-debugger protection is enabled
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class ProDecrypter : DecrypterBase {
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readonly uint[] key = new uint[4];
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public ProDecrypter(PeImage peImage, CodeHeader codeHeader)
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: base(peImage, codeHeader) {
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for (int i = 0; i < 4; i++)
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key[i] = be_readUInt32(codeHeader.decryptionKey, i * 4);
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}
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public override MethodBodyHeader decrypt(MethodInfo methodInfo, out byte[] code, out byte[] extraSections) {
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byte[] data = peImage.offsetReadBytes(endOfMetadata + methodInfo.codeOffs, (int)methodInfo.codeSize);
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int numQwords = (int)(methodInfo.codeSize / 8);
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for (int i = 0; i < numQwords; i++) {
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int offset = i * 8;
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uint q0 = be_readUInt32(data, offset);
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uint q1 = be_readUInt32(data, offset + 4);
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const uint magic = 0x9E3779B8;
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uint val = 0xC6EF3700; // magic * 0x20
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for (int j = 0; j < 32; j++) {
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q1 -= ((q0 << 4) + key[2]) ^ (val + q0) ^ ((q0 >> 5) + key[3]);
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q0 -= ((q1 << 4) + key[0]) ^ (val + q1) ^ ((q1 >> 5) + key[1]);
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val -= magic;
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}
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be_writeUInt32(data, offset, q0);
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be_writeUInt32(data, offset + 4, q1);
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}
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return getCodeBytes(data, out code, out extraSections);
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}
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static uint be_readUInt32(byte[] data, int offset) {
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return (uint)((data[offset] << 24) +
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(data[offset + 1] << 16) +
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(data[offset + 2] << 8) +
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data[offset + 3]);
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}
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static void be_writeUInt32(byte[] data, int offset, uint value) {
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data[offset] = (byte)(value >> 24);
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data[offset + 1] = (byte)(value >> 16);
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data[offset + 2] = (byte)(value >> 8);
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data[offset + 3] = (byte)value;
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}
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}
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interface ICsHeader {
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IDecrypter createDecrypter();
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List<MethodInfo> getMethodInfos(uint codeHeaderOffset);
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void patchMethodDefTable(MetadataType methodDefTable, IList<MethodInfo> methodInfos);
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}
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abstract class CsHeaderBase : ICsHeader {
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protected readonly MethodsDecrypter methodsDecrypter;
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protected readonly uint codeHeaderSize;
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public CsHeaderBase(MethodsDecrypter methodsDecrypter, uint codeHeaderSize) {
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this.methodsDecrypter = methodsDecrypter;
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this.codeHeaderSize = codeHeaderSize;
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}
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public abstract IDecrypter createDecrypter();
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public virtual void patchMethodDefTable(MetadataType methodDefTable, IList<MethodInfo> methodInfos) {
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}
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public abstract List<MethodInfo> getMethodInfos(uint codeHeaderOffset);
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protected List<MethodInfo> getMethodInfos1(uint codeHeaderOffset) {
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uint offset = codeHeaderOffset + methodsDecrypter.codeHeader.totalCodeSize + codeHeaderSize;
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var methodInfos = new List<MethodInfo>((int)methodsDecrypter.codeHeader.numMethods);
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for (int i = 0; i < (int)methodsDecrypter.codeHeader.numMethods; i++, offset += 4) {
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uint codeOffs = methodsDecrypter.peImage.offsetReadUInt32(offset);
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methodInfos.Add(new MethodInfo(codeOffs, 0, 0, 0));
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}
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return methodInfos;
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}
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protected List<MethodInfo> getMethodInfos2(uint codeHeaderOffset) {
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uint offset = codeHeaderOffset + methodsDecrypter.codeHeader.totalCodeSize + codeHeaderSize;
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var methodInfos = new List<MethodInfo>((int)methodsDecrypter.codeHeader.numMethods);
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for (int i = 0; i < (int)methodsDecrypter.codeHeader.numMethods; i++, offset += 8) {
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uint codeOffs = methodsDecrypter.peImage.offsetReadUInt32(offset);
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uint codeSize = methodsDecrypter.peImage.offsetReadUInt32(offset + 4);
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methodInfos.Add(new MethodInfo(codeOffs, codeSize, 0, 0));
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}
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return methodInfos;
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}
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protected List<MethodInfo> getMethodInfos4(uint codeHeaderOffset) {
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uint offset = codeHeaderOffset + methodsDecrypter.codeHeader.totalCodeSize + codeHeaderSize;
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var methodInfos = new List<MethodInfo>((int)methodsDecrypter.codeHeader.numMethods);
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for (int i = 0; i < (int)methodsDecrypter.codeHeader.numMethods; i++, offset += 16) {
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uint codeOffs = methodsDecrypter.peImage.offsetReadUInt32(offset);
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uint codeSize = methodsDecrypter.peImage.offsetReadUInt32(offset + 4);
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uint flags = methodsDecrypter.peImage.offsetReadUInt32(offset + 8);
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uint localVarSigTok = methodsDecrypter.peImage.offsetReadUInt32(offset + 12);
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methodInfos.Add(new MethodInfo(codeOffs, codeSize, flags, localVarSigTok));
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}
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return methodInfos;
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}
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}
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// CS 3.0 (could be other versions too)
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class CsHeader30 : CsHeaderBase {
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public CsHeader30(MethodsDecrypter methodsDecrypter)
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: base(methodsDecrypter, 0x28) {
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}
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public override IDecrypter createDecrypter() {
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return new Decrypter30(methodsDecrypter.peImage, methodsDecrypter.codeHeader);
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}
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public override List<MethodInfo> getMethodInfos(uint codeHeaderOffset) {
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return getMethodInfos1(codeHeaderOffset);
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}
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}
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// CS 4.0 (could be other versions too)
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class CsHeader40 : CsHeaderBase {
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public CsHeader40(MethodsDecrypter methodsDecrypter)
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: base(methodsDecrypter, 0x28) {
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}
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public override IDecrypter createDecrypter() {
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return new Decrypter40(methodsDecrypter.peImage, methodsDecrypter.codeHeader);
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}
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public override List<MethodInfo> getMethodInfos(uint codeHeaderOffset) {
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return getMethodInfos1(codeHeaderOffset);
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}
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}
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// CS 4.5 (could be other versions too)
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class CsHeader45 : CsHeaderBase {
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public CsHeader45(MethodsDecrypter methodsDecrypter)
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: base(methodsDecrypter, 0x28) {
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}
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public override IDecrypter createDecrypter() {
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return new Decrypter45(methodsDecrypter.peImage, methodsDecrypter.codeHeader);
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}
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public override List<MethodInfo> getMethodInfos(uint codeHeaderOffset) {
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return getMethodInfos2(codeHeaderOffset);
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}
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}
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// CS 5.0+
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class CsHeader5 : CsHeaderBase {
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public CsHeader5(MethodsDecrypter methodsDecrypter, uint codeHeaderSize)
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: base(methodsDecrypter, codeHeaderSize) {
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}
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public override IDecrypter createDecrypter() {
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switch (getSigType(methodsDecrypter.codeHeader.signature)) {
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case SigType.Normal:
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return new Decrypter5(methodsDecrypter.peImage, methodsDecrypter.codeHeader, codeHeaderSize);
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case SigType.Pro:
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return new ProDecrypter(methodsDecrypter.peImage, methodsDecrypter.codeHeader);
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case SigType.Unknown:
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default:
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throw new ArgumentException("sig");
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}
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}
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public override List<MethodInfo> getMethodInfos(uint codeHeaderOffset) {
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if (codeHeaderSize == 0x28)
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return getMethodInfos2(codeHeaderOffset);
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return getMethodInfos4(codeHeaderOffset);
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}
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public override void patchMethodDefTable(MetadataType methodDefTable, IList<MethodInfo> methodInfos) {
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uint offset = methodDefTable.fileOffset - methodDefTable.totalSize;
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foreach (var methodInfo in methodInfos) {
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offset += methodDefTable.totalSize;
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if (methodInfo.flags == 0 || methodInfo.codeOffs == 0)
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continue;
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uint rva = methodsDecrypter.peImage.offsetReadUInt32(offset);
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methodsDecrypter.peImage.writeUInt16(rva, (ushort)methodInfo.flags);
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methodsDecrypter.peImage.writeUInt32(rva + 8, methodInfo.localVarSigTok);
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}
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}
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}
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enum CsHeaderVersion {
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Unknown,
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V10,
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V30,
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V40,
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V45,
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V50, // 5.0, possibly also 5.1
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V52, // 5.2+ (or maybe 5.1+)
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}
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List<CsHeaderVersion> getCsHeaderVersions(uint codeHeaderOffset, MetadataType methodDefTable) {
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if (sigType == SigType.Old)
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return new List<CsHeaderVersion> { CsHeaderVersion.V10 };
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if (!isOldHeader(methodDefTable))
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return new List<CsHeaderVersion> { CsHeaderVersion.V52 };
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if (csRtType.isAtLeastVersion50())
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return new List<CsHeaderVersion> { CsHeaderVersion.V50 };
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if (isCsHeader40(codeHeaderOffset)) {
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return new List<CsHeaderVersion> {
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CsHeaderVersion.V40,
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CsHeaderVersion.V30,
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};
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}
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return new List<CsHeaderVersion> {
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CsHeaderVersion.V45,
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CsHeaderVersion.V50,
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};
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}
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bool isCsHeader40(uint codeHeaderOffset) {
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try {
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uint offset = codeHeaderOffset + codeHeader.totalCodeSize + 0x28;
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uint prevCodeOffs = 0;
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for (int i = 0; i < (int)codeHeader.numMethods; i++, offset += 4) {
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uint codeOffs = peImage.offsetReadUInt32(offset);
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if (prevCodeOffs != 0 && codeOffs != 0 && codeOffs < prevCodeOffs)
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return false;
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if (codeOffs != 0)
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prevCodeOffs = codeOffs;
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}
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return true;
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}
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catch (IOException) {
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return false;
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}
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}
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bool isOldHeader(MetadataType methodDefTable) {
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if (methodDefTable.totalSize != codeHeader.methodDefElemSize)
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return true;
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if (methodDefTable.fileOffset - peImage.rvaToOffset(peImage.Cor20Header.metadataDirectory.virtualAddress) != codeHeader.methodDefTableOffset)
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return true;
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return false;
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}
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ICsHeader createCsHeader(CsHeaderVersion version) {
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switch (version) {
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case CsHeaderVersion.V30: return new CsHeader30(this);
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case CsHeaderVersion.V40: return new CsHeader40(this);
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case CsHeaderVersion.V45: return new CsHeader45(this);
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case CsHeaderVersion.V50: return new CsHeader5(this, 0x28);
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case CsHeaderVersion.V52: return new CsHeader5(this, 0x30);
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default: throw new ApplicationException("Unknown CS header");
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}
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}
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enum DecryptResult {
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NotEncrypted,
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Decrypted,
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Error,
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}
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public bool decrypt(PeImage peImage, ModuleDefMD module, CliSecureRtType csRtType, ref DumpedMethods dumpedMethods) {
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this.peImage = peImage;
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this.csRtType = csRtType;
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this.module = module;
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switch (decrypt2(ref dumpedMethods)) {
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case DecryptResult.Decrypted: return true;
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case DecryptResult.NotEncrypted: return false;
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case DecryptResult.Error:
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Log.w("Using dynamic method decryption");
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byte[] moduleCctorBytes = getModuleCctorBytes(csRtType);
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dumpedMethods = de4dot.code.deobfuscators.MethodsDecrypter.decrypt(module.Location, moduleCctorBytes);
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return true;
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default:
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throw new ApplicationException("Invalid DecryptResult");
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}
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}
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static byte[] getModuleCctorBytes(CliSecureRtType csRtType) {
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var initMethod = csRtType.InitializeMethod;
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if (initMethod == null)
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return null;
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uint initToken = initMethod.MDToken.ToUInt32();
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var moduleCctorBytes = new byte[6];
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moduleCctorBytes[0] = 0x28; // call
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moduleCctorBytes[1] = (byte)initToken;
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moduleCctorBytes[2] = (byte)(initToken >> 8);
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moduleCctorBytes[3] = (byte)(initToken >> 16);
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|
moduleCctorBytes[4] = (byte)(initToken >> 24);
|
|
moduleCctorBytes[5] = 0x2A; // ret
|
|
return moduleCctorBytes;
|
|
}
|
|
|
|
static uint getCodeHeaderOffset(PeImage peImage) {
|
|
return peImage.rvaToOffset(peImage.Cor20Header.metadataDirectory.virtualAddress + peImage.Cor20Header.metadataDirectory.size);
|
|
}
|
|
|
|
static string[] sections = new string[] {
|
|
".text", ".rsrc", ".data", ".rdata",
|
|
};
|
|
static uint getOldCodeHeaderOffset(PeImage peImage) {
|
|
var sect = getLastOf(peImage, sections);
|
|
if (sect == null || sect.virtualSize < 0x100)
|
|
return 0;
|
|
return peImage.rvaToOffset(sect.virtualAddress + sect.virtualSize - 0x100);
|
|
}
|
|
|
|
static SectionHeader getLastOf(PeImage peImage, string[] sections) {
|
|
SectionHeader sect = null;
|
|
foreach (var name in sections) {
|
|
var sect2 = peImage.findSection(name);
|
|
if (sect2 == null)
|
|
continue;
|
|
if (sect == null || sect2.virtualAddress > sect.virtualAddress)
|
|
sect = sect2;
|
|
}
|
|
return sect;
|
|
}
|
|
|
|
DecryptResult decrypt2(ref DumpedMethods dumpedMethods) {
|
|
uint codeHeaderOffset = initializeCodeHeader();
|
|
if (sigType == SigType.Unknown)
|
|
return DecryptResult.NotEncrypted;
|
|
|
|
var metadataTables = peImage.Cor20Header.createMetadataTables();
|
|
var methodDefTable = metadataTables.getMetadataType(MetadataIndex.iMethodDef);
|
|
|
|
foreach (var version in getCsHeaderVersions(codeHeaderOffset, methodDefTable)) {
|
|
try {
|
|
if (version == CsHeaderVersion.V10)
|
|
decryptMethodsOld(methodDefTable, ref dumpedMethods);
|
|
else
|
|
decryptMethods(codeHeaderOffset, methodDefTable, createCsHeader(version), ref dumpedMethods);
|
|
return DecryptResult.Decrypted;
|
|
}
|
|
catch {
|
|
}
|
|
}
|
|
|
|
return DecryptResult.Error;
|
|
}
|
|
|
|
uint initializeCodeHeader() {
|
|
uint codeHeaderOffset = getCodeHeaderOffset(peImage);
|
|
readCodeHeader(codeHeaderOffset);
|
|
sigType = getSigType(codeHeader.signature);
|
|
|
|
if (sigType == SigType.Unknown) {
|
|
codeHeaderOffset = getOldCodeHeaderOffset(peImage);
|
|
if (codeHeaderOffset != 0) {
|
|
readCodeHeader(codeHeaderOffset);
|
|
sigType = getSigType(codeHeader.signature);
|
|
}
|
|
}
|
|
|
|
return codeHeaderOffset;
|
|
}
|
|
|
|
void decryptMethodsOld(MetadataType methodDefTable, ref DumpedMethods dumpedMethods) {
|
|
dumpedMethods = new DumpedMethods();
|
|
uint offset = methodDefTable.fileOffset;
|
|
var decrypter = new Decrypter10(peImage, codeHeader.decryptionKey);
|
|
for (int i = 0; i < methodDefTable.rows; i++, offset += methodDefTable.totalSize) {
|
|
var dm = new DumpedMethod();
|
|
dm.token = 0x06000001 + (uint)i;
|
|
|
|
var method = (MethodDef)module.ResolveMethod(MDToken.ToRID(dm.token));
|
|
if (method == null || method.DeclaringType == DotNetUtils.getModuleType(module))
|
|
continue;
|
|
|
|
uint rva = peImage.offsetReadUInt32(offset + (uint)methodDefTable.fields[0].offset);
|
|
if (rva == 0)
|
|
continue;
|
|
uint bodyOffset = peImage.rvaToOffset(rva);
|
|
dm.mdRVA = peImage.offsetRead(offset + (uint)methodDefTable.fields[0].offset, methodDefTable.fields[0].size);
|
|
dm.mdImplFlags = peImage.offsetReadUInt16(offset + (uint)methodDefTable.fields[1].offset);
|
|
dm.mdFlags = peImage.offsetReadUInt16(offset + (uint)methodDefTable.fields[2].offset);
|
|
dm.mdName = peImage.offsetRead(offset + (uint)methodDefTable.fields[3].offset, methodDefTable.fields[3].size);
|
|
dm.mdSignature = peImage.offsetRead(offset + (uint)methodDefTable.fields[4].offset, methodDefTable.fields[4].size);
|
|
dm.mdParamList = peImage.offsetRead(offset + (uint)methodDefTable.fields[5].offset, methodDefTable.fields[5].size);
|
|
|
|
var mbHeader = decrypter.decrypt(bodyOffset, out dm.code, out dm.extraSections);
|
|
dm.mhFlags = mbHeader.flags;
|
|
dm.mhMaxStack = mbHeader.maxStack;
|
|
dm.mhCodeSize = (uint)dm.code.Length;
|
|
dm.mhLocalVarSigTok = mbHeader.localVarSigTok;
|
|
|
|
dumpedMethods.add(dm);
|
|
}
|
|
}
|
|
|
|
void decryptMethods(uint codeHeaderOffset, MetadataType methodDefTable, ICsHeader csHeader, ref DumpedMethods dumpedMethods) {
|
|
var methodInfos = csHeader.getMethodInfos(codeHeaderOffset);
|
|
csHeader.patchMethodDefTable(methodDefTable, methodInfos);
|
|
|
|
dumpedMethods = new DumpedMethods();
|
|
uint offset = methodDefTable.fileOffset;
|
|
decrypter = csHeader.createDecrypter();
|
|
for (int i = 0; i < methodInfos.Count; i++, offset += methodDefTable.totalSize) {
|
|
var methodInfo = methodInfos[i];
|
|
if (methodInfo.codeOffs == 0)
|
|
continue;
|
|
|
|
var dm = new DumpedMethod();
|
|
dm.token = 0x06000001 + (uint)i;
|
|
|
|
dm.mdRVA = peImage.offsetRead(offset + (uint)methodDefTable.fields[0].offset, methodDefTable.fields[0].size);
|
|
dm.mdImplFlags = peImage.offsetReadUInt16(offset + (uint)methodDefTable.fields[1].offset);
|
|
dm.mdFlags = peImage.offsetReadUInt16(offset + (uint)methodDefTable.fields[2].offset);
|
|
dm.mdName = peImage.offsetRead(offset + (uint)methodDefTable.fields[3].offset, methodDefTable.fields[3].size);
|
|
dm.mdSignature = peImage.offsetRead(offset + (uint)methodDefTable.fields[4].offset, methodDefTable.fields[4].size);
|
|
dm.mdParamList = peImage.offsetRead(offset + (uint)methodDefTable.fields[5].offset, methodDefTable.fields[5].size);
|
|
|
|
var mbHeader = decrypter.decrypt(methodInfo, out dm.code, out dm.extraSections);
|
|
dm.mhFlags = mbHeader.flags;
|
|
dm.mhMaxStack = mbHeader.maxStack;
|
|
dm.mhCodeSize = (uint)dm.code.Length;
|
|
dm.mhLocalVarSigTok = mbHeader.localVarSigTok;
|
|
|
|
dumpedMethods.add(dm);
|
|
}
|
|
}
|
|
|
|
void readCodeHeader(uint offset) {
|
|
codeHeader.signature = peImage.offsetReadBytes(offset, 16);
|
|
codeHeader.decryptionKey = peImage.offsetReadBytes(offset + 0x10, 16);
|
|
codeHeader.totalCodeSize = peImage.offsetReadUInt32(offset + 0x20);
|
|
codeHeader.numMethods = peImage.offsetReadUInt32(offset + 0x24);
|
|
codeHeader.methodDefTableOffset = peImage.offsetReadUInt32(offset + 0x28);
|
|
codeHeader.methodDefElemSize = peImage.offsetReadUInt32(offset + 0x2C);
|
|
}
|
|
|
|
static SigType getSigType(byte[] sig) {
|
|
if (Utils.compare(sig, normalSignature))
|
|
return SigType.Normal;
|
|
else if (Utils.compare(sig, proSignature))
|
|
return SigType.Pro;
|
|
else if (Utils.compare(sig, oldSignature))
|
|
return SigType.Old;
|
|
return SigType.Unknown;
|
|
}
|
|
|
|
static bool isValidSignature(byte[] signature) {
|
|
return getSigType(signature) != SigType.Unknown;
|
|
}
|
|
|
|
public static bool detect(PeImage peImage) {
|
|
try {
|
|
uint codeHeaderOffset = getCodeHeaderOffset(peImage);
|
|
if (isValidSignature(peImage.offsetReadBytes(codeHeaderOffset, 16)))
|
|
return true;
|
|
}
|
|
catch {
|
|
}
|
|
|
|
try {
|
|
uint codeHeaderOffset = getOldCodeHeaderOffset(peImage);
|
|
if (codeHeaderOffset != 0 && isValidSignature(peImage.offsetReadBytes(codeHeaderOffset, 16)))
|
|
return true;
|
|
}
|
|
catch {
|
|
}
|
|
|
|
return false;
|
|
}
|
|
}
|
|
}
|