376 lines
11 KiB
C#
376 lines
11 KiB
C#
/*
|
|
Copyright (C) 2011-2013 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;
|
|
|
|
namespace de4dot.code.deobfuscators.MaxtoCode {
|
|
class CryptDecrypter {
|
|
byte[] key;
|
|
|
|
static readonly byte[] sbox = new byte[8 * 8 * 8] {
|
|
14, 4, 13, 1, 2, 15, 11, 8,
|
|
3, 10, 6, 12, 5, 9, 0, 7,
|
|
0, 15, 7, 4, 14, 2, 13, 1,
|
|
10, 6, 12, 11, 9, 5, 3, 8,
|
|
4, 1, 14, 8, 13, 6, 2, 11,
|
|
15, 12, 9, 7, 3, 10, 5, 0,
|
|
15, 12, 8, 2, 4, 9, 1, 7,
|
|
5, 11, 3, 14, 10, 0, 6, 13,
|
|
15, 1, 8, 14, 6, 11, 3, 4,
|
|
9, 7, 2, 13, 12, 0, 5, 10,
|
|
3, 13, 4, 7, 15, 2, 8, 14,
|
|
12, 0, 1, 10, 6, 9, 11, 5,
|
|
0, 14, 7, 11, 10, 4, 13, 1,
|
|
5, 8, 12, 6, 9, 3, 2, 15,
|
|
13, 8, 10, 1, 3, 15, 4, 2,
|
|
11, 6, 7, 12, 0, 5, 14, 9,
|
|
10, 0, 9, 14, 6, 3, 15, 5,
|
|
1, 13, 12, 7, 11, 4, 2, 8,
|
|
13, 7, 0, 9, 3, 4, 6, 10,
|
|
2, 8, 5, 14, 12, 11, 15, 1,
|
|
13, 6, 4, 9, 8, 15, 3, 0,
|
|
11, 1, 2, 12, 5, 10, 14, 7,
|
|
1, 10, 13, 0, 6, 9, 8, 7,
|
|
4, 15, 14, 3, 11, 5, 2, 12,
|
|
7, 13, 14, 3, 0, 6, 9, 10,
|
|
1, 2, 8, 5, 11, 12, 4, 15,
|
|
13, 8, 11, 5, 6, 15, 0, 3,
|
|
4, 7, 2, 12, 1, 10, 14, 9,
|
|
10, 6, 9, 0, 12, 11, 7, 13,
|
|
15, 1, 3, 14, 5, 2, 8, 4,
|
|
3, 15, 0, 6, 10, 1, 13, 8,
|
|
9, 4, 5, 11, 12, 7, 2, 14,
|
|
2, 12, 4, 1, 7, 10, 11, 6,
|
|
8, 5, 3, 15, 13, 0, 14, 9,
|
|
14, 11, 2, 12, 4, 7, 13, 1,
|
|
5, 0, 15, 10, 3, 9, 8, 6,
|
|
4, 2, 1, 11, 10, 13, 7, 8,
|
|
15, 9, 12, 5, 6, 3, 0, 14,
|
|
11, 8, 12, 7, 1, 14, 2, 13,
|
|
6, 15, 0, 9, 10, 4, 5, 3,
|
|
12, 1, 10, 15, 9, 2, 6, 8,
|
|
0, 13, 3, 4, 14, 7, 5, 11,
|
|
10, 15, 4, 2, 7, 12, 9, 5,
|
|
6, 1, 13, 14, 0, 11, 3, 8,
|
|
9, 14, 15, 5, 2, 8, 12, 3,
|
|
7, 0, 4, 10, 1, 13, 11, 6,
|
|
4, 3, 2, 12, 9, 5, 15, 10,
|
|
11, 14, 1, 7, 6, 0, 8, 13,
|
|
4, 11, 2, 14, 15, 0, 8, 13,
|
|
3, 12, 9, 7, 5, 10, 6, 1,
|
|
13, 0, 11, 7, 4, 9, 1, 10,
|
|
14, 3, 5, 12, 2, 15, 8, 6,
|
|
1, 4, 11, 13, 12, 3, 7, 14,
|
|
10, 15, 6, 8, 0, 5, 9, 2,
|
|
6, 11, 13, 8, 1, 4, 10, 7,
|
|
9, 5, 0, 15, 14, 2, 3, 12,
|
|
13, 2, 8, 4, 6, 15, 11, 1,
|
|
10, 9, 3, 14, 5, 0, 12, 7,
|
|
1, 15, 13, 8, 10, 3, 7, 4,
|
|
12, 5, 6, 11, 0, 14, 9, 2,
|
|
7, 11, 4, 1, 9, 12, 14, 2,
|
|
0, 6, 10, 13, 15, 3, 5, 8,
|
|
2, 1, 14, 7, 4, 10, 8, 13,
|
|
15, 12, 9, 0, 3, 5, 6, 11,
|
|
};
|
|
static readonly byte[] perm = new byte[32] {
|
|
16, 7, 20, 21, 29, 12, 28, 17,
|
|
1, 15, 23, 26, 5, 18, 31, 10,
|
|
2, 8, 24, 14, 32, 27, 3, 9,
|
|
19, 13, 30, 6, 22, 11, 4, 25,
|
|
};
|
|
static readonly byte[] esel = new byte[48] {
|
|
32, 1, 2, 3, 4, 5, 4, 5,
|
|
6, 7, 8, 9, 8, 9, 10, 11,
|
|
12, 13, 12, 13, 14, 15, 16, 17,
|
|
16, 17, 18, 19, 20, 21, 20, 21,
|
|
22, 23, 24, 25, 24, 25, 26, 27,
|
|
28, 29, 28, 29, 30, 31, 32, 1,
|
|
};
|
|
static readonly byte[] ip = new byte[64] {
|
|
58, 50, 42, 34, 26, 18, 10, 2,
|
|
60, 52, 44, 36, 28, 20, 12, 4,
|
|
62, 54, 46, 38, 30, 22, 14, 6,
|
|
64, 56, 48, 40, 32, 24, 16, 8,
|
|
57, 49, 41, 33, 25, 17, 9, 1,
|
|
59, 51, 43, 35, 27, 19, 11, 3,
|
|
61, 53, 45, 37, 29, 21, 13, 5,
|
|
63, 55, 47, 39, 31, 23, 15, 7,
|
|
};
|
|
static readonly byte[] final = new byte[64] {
|
|
40, 8, 48, 16, 56, 24, 64, 32,
|
|
39, 7, 47, 15, 55, 23, 63, 31,
|
|
38, 6, 46, 14, 54, 22, 62, 30,
|
|
37, 5, 45, 13, 53, 21, 61, 29,
|
|
36, 4, 44, 12, 52, 20, 60, 28,
|
|
35, 3, 43, 11, 51, 19, 59, 27,
|
|
34, 2, 42, 10, 50, 18, 58, 26,
|
|
33, 1, 41, 9, 49, 17, 57, 25,
|
|
};
|
|
static readonly byte[] pc1 = new byte[56] {
|
|
57, 49, 41, 33, 25, 17, 9, 1,
|
|
58, 50, 42, 34, 26, 18, 10, 2,
|
|
59, 51, 43, 35, 27, 19, 11, 3,
|
|
60, 52, 44, 36, 63, 55, 47, 39,
|
|
31, 23, 15, 7, 62, 54, 46, 38,
|
|
30, 22, 14, 6, 61, 53, 45, 37,
|
|
29, 21, 13, 5, 28, 20, 12, 4,
|
|
};
|
|
static readonly byte[] pc2 = new byte[48] {
|
|
14, 17, 11, 24, 1, 5, 3, 28,
|
|
15, 6, 21, 10, 23, 19, 12, 4,
|
|
26, 8, 16, 7, 27, 20, 13, 2,
|
|
41, 52, 31, 37, 47, 55, 30, 40,
|
|
51, 45, 33, 48, 44, 49, 39, 56,
|
|
34, 53, 46, 42, 50, 36, 29, 32,
|
|
};
|
|
static readonly byte[] rots = new byte[16] {
|
|
1, 1, 2, 2, 2, 2, 2, 2, 1, 2, 2, 2, 2, 2, 2, 1,
|
|
};
|
|
|
|
struct Bits {
|
|
readonly byte[] byteBits;
|
|
|
|
public static Bits fromBytes(byte[] bytes) {
|
|
return fromBytes(bytes, 0, bytes.Length * 8);
|
|
}
|
|
|
|
public static Bits fromBytes(byte[] bytes, int index, int numBits) {
|
|
return new Bits(bytes, index, numBits);
|
|
}
|
|
|
|
public static Bits fromByteBits(byte[] byteBits1, byte[] byteBits2) {
|
|
return new Bits(byteBits1, byteBits2);
|
|
}
|
|
|
|
public static Bits fromByteBits(byte[] byteBits) {
|
|
return fromByteBits(byteBits, 0, byteBits.Length);
|
|
}
|
|
|
|
public static Bits fromByteBits(byte[] byteBits, int index, int numBits) {
|
|
var bits = new Bits(numBits);
|
|
for (int i = 0; i < numBits; i++)
|
|
bits.byteBits[i] = byteBits[index + i];
|
|
return bits;
|
|
}
|
|
|
|
public byte this[int index] {
|
|
get { return byteBits[index]; }
|
|
}
|
|
|
|
public byte[] ByteBits {
|
|
get { return byteBits; }
|
|
}
|
|
|
|
Bits(int numBits) {
|
|
this.byteBits = new byte[numBits];
|
|
}
|
|
|
|
Bits(byte[] bytes1, byte[] bytes2) {
|
|
this.byteBits = concat(bytes1, bytes2);
|
|
}
|
|
|
|
Bits(byte[] bytes, int index, int numBits) {
|
|
this.byteBits = toByteBits(bytes, index, numBits);
|
|
}
|
|
|
|
static byte[] toByteBits(byte[] bytes, int index, int numBits) {
|
|
var byteBits = new byte[numBits];
|
|
for (int i = 0; i < numBits; i++) {
|
|
int j = i / 8;
|
|
int k = i & 7;
|
|
byteBits[i] = (byte)(((bytes[index + j] >> k) & 1) != 0 ? 1 : 0);
|
|
}
|
|
return byteBits;
|
|
}
|
|
|
|
static byte[] concat(byte[] bytes1, byte[] bytes2) {
|
|
var bytes = new byte[bytes1.Length + bytes2.Length];
|
|
Array.Copy(bytes1, 0, bytes, 0, bytes1.Length);
|
|
Array.Copy(bytes2, 0, bytes, bytes1.Length, bytes2.Length);
|
|
return bytes;
|
|
}
|
|
|
|
public Bits transpose(byte[] bits) {
|
|
var result = new Bits(bits.Length);
|
|
for (int i = 0; i < bits.Length; i++)
|
|
result.byteBits[i] = byteBits[bits[i] - 1];
|
|
return result;
|
|
}
|
|
|
|
public void rol() {
|
|
if (byteBits.Length == 0)
|
|
return;
|
|
var first = byteBits[0];
|
|
for (int i = 1; i < byteBits.Length; i++)
|
|
byteBits[i - 1] = byteBits[i];
|
|
byteBits[byteBits.Length - 1] = first;
|
|
}
|
|
|
|
public void rol(int num) {
|
|
for (int i = 0; i < num; i++)
|
|
rol();
|
|
}
|
|
|
|
public Bits extract(int index, int numBits) {
|
|
return fromByteBits(byteBits, index, numBits);
|
|
}
|
|
|
|
public void toBits(byte[] dest, int index) {
|
|
var bits = toBits();
|
|
Array.Copy(bits, 0, dest, index, bits.Length);
|
|
}
|
|
|
|
public byte[] toBits() {
|
|
var bits = new byte[(byteBits.Length + 7) / 8];
|
|
for (int i = 0; i < bits.Length; i++) {
|
|
byte val = 0;
|
|
for (int j = i * 8, k = 1; j < byteBits.Length; j++, k <<= 1) {
|
|
if (byteBits[j] != 0)
|
|
val |= (byte)k;
|
|
}
|
|
bits[i] = val;
|
|
}
|
|
return bits;
|
|
}
|
|
|
|
public Bits clone() {
|
|
return fromByteBits(byteBits, 0, byteBits.Length);
|
|
}
|
|
|
|
public void set(int destIndex, Bits other) {
|
|
for (int i = 0; i < other.byteBits.Length; i++)
|
|
byteBits[destIndex + i] = other.byteBits[i];
|
|
}
|
|
|
|
public void xor(Bits other) {
|
|
if (byteBits.Length != other.byteBits.Length)
|
|
throw new ArgumentException("other");
|
|
for (int i = 0; i < byteBits.Length; i++)
|
|
byteBits[i] ^= other.byteBits[i];
|
|
}
|
|
|
|
public void copyTo(byte[] dest, int index) {
|
|
for (int i = 0; i < byteBits.Length; i++)
|
|
dest[index + i] = byteBits[i];
|
|
}
|
|
}
|
|
|
|
public CryptDecrypter(byte[] key) {
|
|
if (key.Length <= 8)
|
|
throw new ArgumentException("Invalid size", "key");
|
|
this.key = key;
|
|
}
|
|
|
|
public static byte[] decrypt(byte[] key, byte[] encrypted) {
|
|
return new CryptDecrypter(key).decrypt(encrypted);
|
|
}
|
|
|
|
byte[] decrypt(byte[] encrypted) {
|
|
if (encrypted.Length % 8 != 0)
|
|
throw new ArgumentException("encrypted");
|
|
var key1 = createKey(key, 0);
|
|
var key2 = createKey(key, 8);
|
|
|
|
var decrypted = new byte[encrypted.Length];
|
|
int count = encrypted.Length / 8;
|
|
for (int i = 0; i < count; i++) {
|
|
var buf = new byte[8];
|
|
Array.Copy(encrypted, i * 8, buf, 0, buf.Length);
|
|
buf = decrypt(buf, key1, true);
|
|
buf = decrypt(buf, key2, false);
|
|
buf = decrypt(buf, key1, true);
|
|
Array.Copy(buf, 0, decrypted, i * 8, buf.Length);
|
|
}
|
|
|
|
return decrypted;
|
|
}
|
|
|
|
byte[] decrypt(byte[] data, Bits key, bool flag) {
|
|
var bits = Bits.fromBytes(data).transpose(ip);
|
|
|
|
if (flag) {
|
|
for (int i = 0, ki = key.ByteBits.Length - 48; i < 16; i++, ki -= 48) {
|
|
var oldBits = bits.extract(0, 32);
|
|
var tmp = decrypt(oldBits.clone(), key.extract(ki, 48));
|
|
tmp.xor(bits.extract(32, 32));
|
|
bits.set(32, oldBits);
|
|
bits.set(0, tmp);
|
|
}
|
|
}
|
|
else {
|
|
for (int i = 0, ki = 0; i < 16; i++, ki += 48) {
|
|
var oldBits = bits.extract(32, 32);
|
|
var tmp = decrypt(oldBits.clone(), key.extract(ki, 48));
|
|
tmp.xor(bits.extract(0, 32));
|
|
bits.set(0, oldBits);
|
|
bits.set(32, tmp);
|
|
}
|
|
}
|
|
|
|
bits = bits.transpose(final);
|
|
return bits.toBits();
|
|
}
|
|
|
|
Bits decrypt(Bits data, Bits key) {
|
|
var newData = data.clone().transpose(esel);
|
|
newData.xor(key);
|
|
return Bits.fromByteBits(getSbox(newData)).transpose(perm);
|
|
}
|
|
|
|
byte[] getSbox(Bits data) {
|
|
var sboxByteBits = new byte[32];
|
|
|
|
for (int i = 0; i < 8; i++) {
|
|
int di = i * 6;
|
|
int index = (data[di + 0] << 5) + (data[di + 5] << 4) + (data[di + 1] << 3) +
|
|
(data[di + 2] << 2) + (data[di + 3] << 1) + data[di + 4] + i * 64;
|
|
Bits.fromBytes(sbox, index, 4).copyTo(sboxByteBits, i * 4);
|
|
}
|
|
|
|
return sboxByteBits;
|
|
}
|
|
|
|
static Bits createKey(byte[] data, int index) {
|
|
Bits key1, key2;
|
|
createKeys(data, index, out key1, out key2);
|
|
byte[] newKey = new byte[16 * 6];
|
|
byte[] tmpData = new byte[28 * 2];
|
|
for (int i = 0; i < 16; i++) {
|
|
int rolCount = rots[i];
|
|
key1.rol(rolCount);
|
|
key2.rol(rolCount);
|
|
Bits.fromByteBits(key1.ByteBits, key2.ByteBits).transpose(pc2).toBits(newKey, i * 6);
|
|
}
|
|
return Bits.fromBytes(newKey);
|
|
}
|
|
|
|
static void createKeys(byte[] data, int index, out Bits key1, out Bits key2) {
|
|
var tmpKey = new byte[8];
|
|
int len = Math.Min(tmpKey.Length, data.Length - index);
|
|
if (len == 0)
|
|
throw new ArgumentException("data");
|
|
Array.Copy(data, index, tmpKey, 0, len);
|
|
var bits = Bits.fromBytes(tmpKey).transpose(pc1);
|
|
key1 = Bits.fromByteBits(bits.ByteBits, 0, 28);
|
|
key2 = Bits.fromByteBits(bits.ByteBits, 28, 28);
|
|
}
|
|
}
|
|
}
|