2011-09-22 10:55:30 +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;
|
|
|
|
|
using System.Text;
|
|
|
|
|
|
2011-12-09 16:02:06 +08:00
|
|
|
|
namespace de4dot.code.deobfuscators.SmartAssembly {
|
2011-09-22 10:55:30 +08:00
|
|
|
|
class StringDecrypter {
|
|
|
|
|
int stringOffset;
|
|
|
|
|
byte[] decryptedData;
|
|
|
|
|
|
|
|
|
|
public bool CanDecrypt {
|
|
|
|
|
get { return decryptedData != null; }
|
|
|
|
|
}
|
|
|
|
|
|
|
|
|
|
public StringDecrypterInfo StringDecrypterInfo { get; private set; }
|
|
|
|
|
|
|
|
|
|
public StringDecrypter(StringDecrypterInfo stringDecrypterInfo) {
|
|
|
|
|
StringDecrypterInfo = stringDecrypterInfo;
|
|
|
|
|
|
|
|
|
|
if (stringDecrypterInfo != null) {
|
|
|
|
|
if (!stringDecrypterInfo.StringsEncrypted) {
|
|
|
|
|
stringOffset = stringDecrypterInfo.StringOffset;
|
|
|
|
|
decryptedData = stringDecrypterInfo.StringsResource.GetResourceData();
|
|
|
|
|
}
|
|
|
|
|
else if (stringDecrypterInfo.CanDecrypt) {
|
|
|
|
|
stringOffset = stringDecrypterInfo.StringOffset;
|
|
|
|
|
decryptedData = stringDecrypterInfo.decrypt();
|
|
|
|
|
}
|
|
|
|
|
}
|
|
|
|
|
}
|
|
|
|
|
|
|
|
|
|
public string decrypt(int token, int id) {
|
|
|
|
|
if (!CanDecrypt)
|
|
|
|
|
throw new ApplicationException("Can't decrypt strings since decryptedData is null");
|
|
|
|
|
|
|
|
|
|
int index = id - (token & 0x00FFFFFF) - stringOffset;
|
|
|
|
|
|
|
|
|
|
int len;
|
|
|
|
|
byte b = decryptedData[index++];
|
|
|
|
|
if ((b & 0x80) == 0)
|
|
|
|
|
len = b;
|
|
|
|
|
else if ((b & 0x40) == 0)
|
|
|
|
|
len = ((b & 0x3F) << 8) + decryptedData[index++];
|
|
|
|
|
else {
|
|
|
|
|
len = ((b & 0x1F) << 24) +
|
|
|
|
|
((int)decryptedData[index++] << 16) +
|
|
|
|
|
((int)decryptedData[index++] << 8) +
|
|
|
|
|
decryptedData[index++];
|
|
|
|
|
}
|
|
|
|
|
|
|
|
|
|
var decodedData = Convert.FromBase64String(Encoding.UTF8.GetString(decryptedData, index, len));
|
|
|
|
|
return Encoding.UTF8.GetString(decodedData, 0, decodedData.Length);
|
|
|
|
|
}
|
|
|
|
|
}
|
|
|
|
|
}
|