GARbro-mirror/ArcFormats/KiriKiri/CryptAlgorithms.cs
2017-02-05 02:31:15 +04:00

901 lines
29 KiB
C#

//! \file CryptAlgorithms.cs
//! \date Thu Feb 04 12:08:40 2016
//! \brief KiriKiri engine encryption algorithms.
//
// Copyright (C) 2016 by morkt
//
// Permission is hereby granted, free of charge, to any person obtaining a copy
// of this software and associated documentation files (the "Software"), to
// deal in the Software without restriction, including without limitation the
// rights to use, copy, modify, merge, publish, distribute, sublicense, and/or
// sell copies of the Software, and to permit persons to whom the Software is
// furnished to do so, subject to the following conditions:
//
// The above copyright notice and this permission notice shall be included in
// all copies or substantial portions of the Software.
//
// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
// IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
// FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
// AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
// LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
// FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS
// IN THE SOFTWARE.
//
using System;
using System.Collections.Generic;
using System.Linq;
using GameRes.Utility;
namespace GameRes.Formats.KiriKiri
{
[Serializable]
public abstract class ICrypt
{
/// <summary>
/// whether Adler32 checksum should be calculated after contents have been encrypted.
/// </summary>
public virtual bool HashAfterCrypt { get { return false; } }
/// <summary>
/// sometimes startup.tjs file is not encrypted.
/// </summary>
public bool StartupTjsNotEncrypted { get; set; }
/// <summary>
/// whether XP3 index is obfuscated:
/// - duplicate entries
/// - entries have additional dummy segments
/// </summary>
public bool ObfuscatedIndex { get; set; }
public virtual byte Decrypt (Xp3Entry entry, long offset, byte value)
{
byte[] buffer = new byte[1] { value };
Decrypt (entry, offset, buffer, 0, 1);
return buffer[0];
}
public abstract void Decrypt (Xp3Entry entry, long offset, byte[] values, int pos, int count);
public virtual void Encrypt (Xp3Entry entry, long offset, byte[] values, int pos, int count)
{
throw new NotImplementedException (Strings.arcStrings.MsgEncNotImplemented);
}
/// <summary>
/// Perform necessary initialization specific to an archive being opened.
/// </summary>
public virtual void Init (ArcFile arc)
{
}
}
[Serializable]
public class NoCrypt : ICrypt
{
public override byte Decrypt (Xp3Entry entry, long offset, byte value)
{
return value;
}
public override void Decrypt (Xp3Entry entry, long offset, byte[] values, int pos, int count)
{
return;
}
public override void Encrypt (Xp3Entry entry, long offset, byte[] values, int pos, int count)
{
return;
}
}
[Serializable]
public class FateCrypt : ICrypt
{
public override bool HashAfterCrypt { get { return true; } }
public override byte Decrypt (Xp3Entry entry, long offset, byte value)
{
byte result = (byte)(value ^ 0x36);
if (0x13 == offset)
result ^= 1;
else if (0x2ea29 == offset)
result ^= 3;
return result;
}
public override void Decrypt (Xp3Entry entry, long offset, byte[] values, int pos, int count)
{
for (int i = 0; i < count; ++i)
{
values[pos+i] ^= 0x36;
}
if (offset > 0x2ea29)
return;
if (offset + count > 0x2ea29)
values[pos+0x2ea29-offset] ^= 3;
if (offset > 0x13)
return;
if (offset + count > 0x13)
values[pos+0x13-offset] ^= 1;
}
public override void Encrypt (Xp3Entry entry, long offset, byte[] values, int pos, int count)
{
Decrypt (entry, offset, values, pos, count);
}
}
[Serializable]
public class MizukakeCrypt : ICrypt
{
public override bool HashAfterCrypt { get { return true; } }
public override void Decrypt (Xp3Entry entry, long offset, byte[] values, int pos, int count)
{
if (offset <= 0x103 && offset + count > 0x103)
values[pos+0x103-offset]--;
for (int i = 0; i < count; ++i)
{
values[pos+i] ^= 0xB6;
}
if (offset > 0x3F82)
return;
if (offset + count > 0x3F82)
values[pos+0x3F82-offset] ^= 1;
if (offset > 0x83)
return;
if (offset + count > 0x83)
values[pos+0x83-offset] ^= 3;
}
public override void Encrypt (Xp3Entry entry, long offset, byte[] values, int pos, int count)
{
for (int i = 0; i < count; ++i)
{
values[pos+i] ^= 0xB6;
}
if (offset <= 0x3F82 && offset + count > 0x3F82)
values[pos+0x3F82-offset] ^= 1;
if (offset <= 0x83 && offset + count > 0x83)
values[pos+0x83-offset] ^= 3;
if (offset <= 0x103 && offset + count > 0x103)
values[pos+0x103-offset]++;
}
}
[Serializable]
public class HashCrypt : ICrypt
{
public override byte Decrypt (Xp3Entry entry, long offset, byte value)
{
return (byte)(value ^ entry.Hash);
}
public override void Decrypt (Xp3Entry entry, long offset, byte[] values, int pos, int count)
{
byte key = (byte)entry.Hash;
for (int i = 0; i < count; ++i)
{
values[pos+i] ^= key;
}
}
public override void Encrypt (Xp3Entry entry, long offset, byte[] values, int pos, int count)
{
Decrypt (entry, offset, values, pos, count);
}
}
[Serializable]
public class XorCrypt : ICrypt
{
private byte m_key;
public byte Key
{
get { return m_key; }
set { m_key = value; }
}
public XorCrypt (uint key)
{
m_key = (byte)key;
}
public override byte Decrypt (Xp3Entry entry, long offset, byte value)
{
return (byte)(value ^ m_key);
}
public override void Decrypt (Xp3Entry entry, long offset, byte[] values, int pos, int count)
{
for (int i = 0; i < count; ++i)
{
values[pos+i] ^= m_key;
}
}
public override void Encrypt (Xp3Entry entry, long offset, byte[] values, int pos, int count)
{
Decrypt (entry, offset, values, pos, count);
}
}
[Serializable]
public class FlyingShineCrypt : ICrypt
{
static private byte Adjust (uint hash, out int shift)
{
shift = (int)(hash & 0xff);
if (0 == shift) shift = 0x0f;
byte key = (byte)(hash >> 8);
if (0 == key) key = 0xf0;
return key;
}
public override byte Decrypt (Xp3Entry entry, long offset, byte value)
{
int shift;
byte xor = Adjust (entry.Hash, out shift);
return Binary.RotByteR ((byte)(value ^ xor), shift);
}
public override void Decrypt (Xp3Entry entry, long offset, byte[] values, int pos, int count)
{
int shift;
byte xor = Adjust (entry.Hash, out shift);
for (int i = 0; i < count; ++i)
{
byte data = (byte)(values[pos+i] ^ xor);
values[pos+i] = Binary.RotByteR (data, shift);
}
}
public override void Encrypt (Xp3Entry entry, long offset, byte[] values, int pos, int count)
{
int shift;
byte xor = Adjust (entry.Hash, out shift);
for (int i = 0; i < count; ++i)
{
byte data = Binary.RotByteL (values[pos+i], shift);
values[pos+i] = (byte)(data ^ xor);
}
}
}
[Serializable]
public class SeitenCrypt : ICrypt
{
public override byte Decrypt (Xp3Entry entry, long offset, byte value)
{
uint key = entry.Hash ^ (uint)offset;
if (0 != (key & 2))
{
int ecx = (int)key & 0x18;
value ^= (byte)((key >> ecx) | (key >> (ecx & 8)));
}
if (0 != (key & 4))
{
value += (byte)key;
}
if (0 != (key & 8))
{
value -= (byte)(key >> (int)(key & 0x10));
}
return value;
}
public override void Decrypt (Xp3Entry entry, long offset, byte[] buffer, int pos, int count)
{
for (int i = 0; i < count; ++i)
{
int shift;
uint key = entry.Hash ^ (uint)offset;
byte v = buffer[pos+i];
if (0 != (key & 2))
{
shift = (int)key & 0x18;
uint ebx = key >> shift;
shift &= 8;
v ^= (byte)(ebx | (key >> shift));
}
if (0 != (key & 4))
{
v += (byte)key;
}
if (0 != (key & 8))
{
shift = (int)key & 0x10;
v -= (byte)(key >> shift);
}
buffer[pos+i] = v;
++offset;
}
}
public override void Encrypt (Xp3Entry entry, long offset, byte[] values, int pos, int count)
{
for (int i = 0; i < count; ++i)
{
uint key = entry.Hash ^ (uint)offset;
if (0 != (key & 8))
{
values[pos+i] += (byte)(key >> (int)(key & 0x10));
}
if (0 != (key & 4))
{
values[pos+i] -= (byte)key;
}
if (0 != (key & 2))
{
int ecx = (int)key & 0x18;
values[pos+i] ^= (byte)((key >> ecx) | (key >> (ecx & 8)));
}
}
}
}
[Serializable]
public class OkibaCrypt : ICrypt
{
public override byte Decrypt (Xp3Entry entry, long offset, byte value)
{
if (offset < 0x65)
return (byte)(value ^ (byte)(entry.Hash >> 4));
uint key = entry.Hash;
// 0,1,2,3 -> 1,0,3,2
key = ((key & 0xff0000) << 8) | ((key & 0xff000000) >> 8)
| ((key & 0xff00) >> 8) | ((key & 0xff) << 8);
key >>= 8 * ((int)(offset - 0x65) & 3);
return (byte)(value ^ (byte)key);
}
public override void Decrypt (Xp3Entry entry, long offset, byte[] values, int pos, int count)
{
int i = 0;
if (offset < 0x65)
{
uint key = entry.Hash >> 4;
int limit = Math.Min (count, (int)(0x65 - offset));
for (; i < limit; ++i)
{
values[pos+i] ^= (byte)key;
++offset;
}
}
if (i < count)
{
offset -= 0x65;
uint key = entry.Hash;
key = ((key & 0xff0000) << 8) | ((key & 0xff000000) >> 8)
| ((key & 0xff00) >> 8) | ((key & 0xff) << 8);
do
{
values[pos+i] ^= (byte)(key >> (8 * ((int)offset & 3)));
++offset;
}
while (++i < count);
}
}
public override void Encrypt (Xp3Entry entry, long offset, byte[] values, int pos, int count)
{
Decrypt (entry, offset, values, pos, count);
}
}
[Serializable]
public class DieselmineCrypt : ICrypt
{
public override byte Decrypt (Xp3Entry entry, long offset, byte value)
{
byte key = (byte)entry.Hash;
if (offset < 123)
value ^= (byte)(21 * key);
else if (offset < 246)
value += (byte)(-32 * key);
else if (offset < 369)
value ^= (byte)(43 * key);
else if (offset <= 0xffffffffL)
value += (byte)(-54 * key);
return value;
}
public override void Decrypt (Xp3Entry entry, long offset, byte[] values, int pos, int count)
{
byte key = (byte)entry.Hash;
for (int i = 0; i < count && offset <= 0xffffffffL; ++i, ++offset)
{
if (offset < 123)
values[pos+i] ^= (byte)(21 * key);
else if (offset < 246)
values[pos+i] += (byte)(-32 * key);
else if (offset < 369)
values[pos+i] ^= (byte)(43 * key);
else
values[pos+i] += (byte)(-54 * key);
}
}
public override void Encrypt (Xp3Entry entry, long offset, byte[] values, int pos, int count)
{
byte key = (byte)entry.Hash;
for (int i = 0; i < count && offset <= 0xffffffffL; ++i, ++offset)
{
if (offset < 123)
values[pos+i] ^= (byte)(21 * key);
else if (offset < 246)
values[pos+i] -= (byte)(-32 * key);
else if (offset < 369)
values[pos+i] ^= (byte)(43 * key);
else
values[pos+i] -= (byte)(-54 * key);
}
}
}
[Serializable]
public class DameganeCrypt : ICrypt
{
public override byte Decrypt (Xp3Entry entry, long offset, byte value)
{
if (0 != (offset & 1))
return (byte)(value ^ entry.Hash);
else
return (byte)(value ^ offset);
}
public override void Decrypt (Xp3Entry entry, long offset, byte[] values, int pos, int count)
{
for (int i = 0; i < count; ++i, ++offset)
{
if (0 != (offset & 1))
values[pos+i] ^= (byte)entry.Hash;
else
values[pos+i] ^= (byte)offset;
}
}
public override void Encrypt (Xp3Entry entry, long offset, byte[] values, int pos, int count)
{
Decrypt (entry, offset, values, pos, count);
}
}
[Serializable]
public class GakuenButouCrypt : ICrypt
{
public override byte Decrypt (Xp3Entry entry, long offset, byte value)
{
if (0 != (offset & 1))
return (byte)(value ^ offset);
else
return (byte)(value ^ entry.Hash);
}
public override void Decrypt (Xp3Entry entry, long offset, byte[] values, int pos, int count)
{
for (int i = 0; i < count; ++i, ++offset)
{
if (0 != (offset & 1))
values[pos+i] ^= (byte)offset;
else
values[pos+i] ^= (byte)entry.Hash;
}
}
public override void Encrypt (Xp3Entry entry, long offset, byte[] values, int pos, int count)
{
Decrypt (entry, offset, values, pos, count);
}
}
[Serializable]
public class AlteredPinkCrypt : ICrypt
{
static readonly byte[] KeyTable = {
0x43, 0xF8, 0xAD, 0x08, 0xDF, 0xB7, 0x26, 0x44, 0xF0, 0xD9, 0xE9, 0x24, 0x1A, 0xC1, 0xEE, 0xB4,
0x11, 0x4B, 0xE4, 0xAF, 0x01, 0x5B, 0xF0, 0xAB, 0x6A, 0x70, 0x78, 0x84, 0xB0, 0x78, 0x4F, 0xED,
0x39, 0x52, 0x69, 0xAF, 0xC4, 0x92, 0x2A, 0x21, 0xDE, 0xDC, 0x6E, 0x63, 0x9D, 0x9B, 0x63, 0xE1,
0xB1, 0x94, 0x40, 0x6E, 0x3A, 0x52, 0x5A, 0x28, 0x08, 0x4D, 0xFB, 0x22, 0x18, 0xEB, 0xBA, 0x98,
0x49, 0x77, 0xBF, 0xAA, 0x43, 0x75, 0xF5, 0xD3, 0x83, 0x71, 0x58, 0xA4, 0xAF, 0x1B, 0x53, 0x99,
0x8A, 0x27, 0x5B, 0xC2, 0x7F, 0x7A, 0xCD, 0x8D, 0x33, 0x59, 0xEB, 0xA6, 0xFA, 0x7C, 0x00, 0x19,
0xC4, 0xAA, 0x24, 0xF8, 0x84, 0xCD, 0xF7, 0x20, 0x4B, 0xAB, 0xF1, 0xD5, 0x01, 0x6F, 0x7C, 0x91,
0x08, 0x7D, 0x8D, 0x89, 0x7C, 0x71, 0x65, 0x99, 0x9B, 0x6F, 0x3A, 0x1C, 0x49, 0xE3, 0xAF, 0x1F,
0xC6, 0xA5, 0x79, 0xFE, 0xAE, 0xA1, 0xCA, 0x59, 0x3C, 0xEE, 0xC1, 0x02, 0xBD, 0x2B, 0x8E, 0xC5,
0x7D, 0x38, 0x80, 0x8F, 0x72, 0xF3, 0x86, 0x5D, 0xF4, 0x20, 0x0A, 0x5B, 0xA0, 0xE3, 0x85, 0xB5,
0x67, 0x43, 0x96, 0xBB, 0x75, 0x86, 0x8D, 0x7E, 0x7E, 0xE6, 0xAA, 0x18, 0x57, 0xC4, 0xAA, 0x87,
0xDC, 0x74, 0x05, 0xAA, 0xBD, 0x5E, 0x4F, 0xA9, 0xB5, 0x5E, 0xC5, 0xE8, 0x11, 0x6D, 0x68, 0x89,
0x17, 0x7C, 0x10, 0x05, 0xA2, 0xBA, 0x43, 0x01, 0xD6, 0xFD, 0x26, 0x19, 0x57, 0xFA, 0x4D, 0x01,
0xB0, 0xED, 0x3A, 0x55, 0xEB, 0x65, 0x8E, 0xD1, 0x58, 0x27, 0xAD, 0xA1, 0x5E, 0x57, 0x3F, 0xA0,
0xEF, 0x59, 0x3E, 0xA4, 0xEB, 0x12, 0x15, 0x60, 0xBE, 0x95, 0x61, 0x0B, 0x98, 0xF5, 0xF4, 0x12,
0x1C, 0xD8, 0x62, 0x3F, 0xFD, 0xCF, 0x01, 0x3A, 0xE7, 0xC2, 0x19, 0x38, 0x6C, 0xC3, 0x90, 0x3E,
};
public override byte Decrypt (Xp3Entry entry, long offset, byte value)
{
return (byte)(value ^ KeyTable[offset & 0xFF]);
}
public override void Decrypt (Xp3Entry entry, long offset, byte[] values, int pos, int count)
{
for (int i = 0; i < count; ++i)
{
values[pos+i] ^= KeyTable[(offset+i) & 0xFF];
}
}
public override void Encrypt (Xp3Entry entry, long offset, byte[] values, int pos, int count)
{
Decrypt (entry, offset, values, pos, count);
}
}
[Serializable]
public class NatsupochiCrypt : ICrypt
{
public override byte Decrypt (Xp3Entry entry, long offset, byte value)
{
return (byte)(value ^ (entry.Hash >> 3));
}
public override void Decrypt (Xp3Entry entry, long offset, byte[] values, int pos, int count)
{
byte key = (byte)(entry.Hash >> 3);
for (int i = 0; i < count; ++i)
{
values[pos+i] ^= key;
}
}
public override void Encrypt (Xp3Entry entry, long offset, byte[] values, int pos, int count)
{
Decrypt (entry, offset, values, pos, count);
}
}
[Serializable]
public class PoringSoftCrypt : ICrypt
{
public override byte Decrypt (Xp3Entry entry, long offset, byte value)
{
return (byte)~(value ^ (entry.Hash + 1));
}
public override void Decrypt (Xp3Entry entry, long offset, byte[] values, int pos, int count)
{
byte key = (byte)~(entry.Hash + 1);
for (int i = 0; i < count; ++i)
{
values[pos+i] ^= key;
}
}
public override void Encrypt (Xp3Entry entry, long offset, byte[] values, int pos, int count)
{
Decrypt (entry, offset, values, pos, count);
}
}
[Serializable]
public class AppliqueCrypt : ICrypt
{
public override byte Decrypt (Xp3Entry entry, long offset, byte value)
{
return offset < 5 ? value : (byte)(value ^ (entry.Hash >> 12));
}
public override void Decrypt (Xp3Entry entry, long offset, byte[] values, int pos, int count)
{
if (offset < 5)
{
int skip = Math.Min (5 - (int)offset, count);
offset += skip;
pos += skip;
count -= skip;
}
byte key = (byte)(entry.Hash >> 12);
for (int i = 0; i < count; ++i)
{
values[pos+i] ^= key;
}
}
public override void Encrypt (Xp3Entry entry, long offset, byte[] values, int pos, int count)
{
Decrypt (entry, offset, values, pos, count);
}
}
[Serializable]
public class TokidokiCrypt : ICrypt
{
public override bool HashAfterCrypt { get { return true; } }
public override void Decrypt (Xp3Entry entry, long offset, byte[] values, int pos, int count)
{
uint key;
uint limit = GetParameters (entry, out key);
for (int i = 0; i < count && offset < limit; ++i, ++offset)
{
values[pos+i] ^= (byte)(key >> (((int)offset & 3) << 3));
}
}
public override void Encrypt (Xp3Entry entry, long offset, byte[] values, int pos, int count)
{
Decrypt (entry, offset, values, pos, count);
}
uint GetParameters (Xp3Entry entry, out uint key)
{
var ext = System.IO.Path.GetExtension (entry.Name);
if (!string.IsNullOrEmpty (ext))
{
ext = ext.ToLowerInvariant();
var ext_bin = new byte[16];
Encodings.cp932.GetBytes (ext, 0, Math.Min (4, ext.Length), ext_bin, 0);
key = ~LittleEndian.ToUInt32 (ext_bin, 0);
if (".asd\0.ks\0.tjs\0".Contains (ext+'\0'))
return entry.Size;
}
else
key = uint.MaxValue;
return Math.Min (entry.Size, 0x100u);
}
}
[Serializable]
public class SourireCrypt : ICrypt
{
public override byte Decrypt (Xp3Entry entry, long offset, byte value)
{
return (byte)(value ^ entry.Hash ^ 0xCD);
}
public override void Decrypt (Xp3Entry entry, long offset, byte[] values, int pos, int count)
{
byte key = (byte)(entry.Hash ^ 0xCD);
for (int i = 0; i < count; ++i)
{
values[pos+i] ^= key;
}
}
public override void Encrypt (Xp3Entry entry, long offset, byte[] values, int pos, int count)
{
Decrypt (entry, offset, values, pos, count);
}
}
[Serializable]
public class HibikiCrypt : ICrypt
{
public override byte Decrypt (Xp3Entry entry, long offset, byte value)
{
if (0 != (offset & 4) || offset <= 0x64)
return (byte)(value ^ (entry.Hash >> 5));
else
return (byte)(value ^ (entry.Hash >> 8));
}
public override void Decrypt (Xp3Entry entry, long offset, byte[] buffer, int pos, int count)
{
byte key1 = (byte)(entry.Hash >> 5);
byte key2 = (byte)(entry.Hash >> 8);
for (int i = 0; i < count; ++i, ++offset)
{
if (0 != (offset & 4) || offset <= 0x64)
buffer[pos+i] ^= key1;
else
buffer[pos+i] ^= key2;
}
}
public override void Encrypt (Xp3Entry entry, long offset, byte[] buffer, int pos, int count)
{
Decrypt (entry, offset, buffer, pos, count);
}
}
[Serializable]
public class AkabeiCrypt : ICrypt
{
private readonly uint m_seed;
public AkabeiCrypt (uint seed)
{
m_seed = seed;
}
public override byte Decrypt (Xp3Entry entry, long offset, byte value)
{
int key_pos = (int)offset & 0x1F;
var key = GetKey (entry.Hash).ElementAt (key_pos);
return (byte)(value ^ key);
}
public override void Decrypt (Xp3Entry entry, long offset, byte[] buffer, int pos, int count)
{
var key = GetKey (entry.Hash).ToArray();
int key_pos = (int)offset;
for (int i = 0; i < count; ++i)
{
buffer[pos+i] ^= key[key_pos++ & 0x1F];
}
}
public override void Encrypt (Xp3Entry entry, long offset, byte[] buffer, int pos, int count)
{
Decrypt (entry, offset, buffer, pos, count);
}
IEnumerable<byte> GetKey (uint hash)
{
hash = (hash ^ m_seed) & 0x7FFFFFFF;
hash = hash << 31 | hash;
for (int i = 0; i < 0x20; ++i)
{
yield return (byte)hash;
hash = (hash & 0xFFFFFFFE) << 23 | hash >> 8;
}
}
}
[Serializable]
public class HaikuoCrypt : ICrypt
{
public override byte Decrypt (Xp3Entry entry, long offset, byte value)
{
return (byte)(value ^ entry.Hash ^ (entry.Hash >> 8));
}
public override void Decrypt (Xp3Entry entry, long offset, byte[] values, int pos, int count)
{
byte key = (byte)(entry.Hash ^ (entry.Hash >> 8));
for (int i = 0; i < count; ++i)
{
values[pos+i] ^= key;
}
}
public override void Encrypt (Xp3Entry entry, long offset, byte[] values, int pos, int count)
{
Decrypt (entry, offset, values, pos, count);
}
}
[Serializable]
public class StripeCrypt : ICrypt
{
readonly byte m_key;
public StripeCrypt (byte key)
{
m_key = key;
}
public override byte Decrypt (Xp3Entry entry, long offset, byte value)
{
return (byte)((value ^ m_key) + 1);
}
public override void Decrypt (Xp3Entry entry, long offset, byte[] values, int pos, int count)
{
for (int i = 0; i < count; ++i)
{
values[pos+i] ^= m_key;
values[pos+i] ++;
}
}
public override void Encrypt (Xp3Entry entry, long offset, byte[] values, int pos, int count)
{
for (int i = 0; i < count; ++i)
{
values[pos+i] --;
values[pos+i] ^= m_key;
}
}
}
[Serializable]
public class ExaCrypt : ICrypt
{
public override byte Decrypt (Xp3Entry entry, long offset, byte value)
{
return (byte)(value ^ (entry.Hash >> (int)((uint)offset % 5)));
}
public override void Decrypt (Xp3Entry entry, long offset, byte[] values, int pos, int count)
{
int shift = (int)(offset % 5);
for (int i = 0; i < count; ++i)
{
values[pos+i] ^= (byte)(entry.Hash >> ((shift+i) % 5));
}
}
public override void Encrypt (Xp3Entry entry, long offset, byte[] values, int pos, int count)
{
Decrypt (entry, offset, values, pos, count);
}
}
[Serializable]
public class SmileCrypt : ICrypt
{
public override void Decrypt (Xp3Entry entry, long offset, byte[] values, int pos, int count)
{
uint hash = entry.Hash ^ 0xD0F0BA7B;
byte key = (byte)(hash ^ (hash >> 8) ^ (hash >> 16) ^ (hash >> 24));
if (0 == key)
key = 0x5E;
if (0 == offset && count > 0)
{
if (0 == (hash & 0xFF))
hash = 0x7B;
values[pos] ^= (byte)hash;
}
for (int i = 0; i < count; ++i)
{
values[pos+i] ^= key;
}
}
public override void Encrypt (Xp3Entry entry, long offset, byte[] values, int pos, int count)
{
Decrypt (entry, offset, values, pos, count);
}
}
// reminder:
// locate virtual table, then find constructor where it's referenced.
[Serializable]
public class YuzuCrypt : ICrypt
{
public override void Decrypt (Xp3Entry entry, long offset, byte[] data, int pos, int count)
{
uint hash = entry.Hash ^ 0x1DDB6E7A;
byte key = (byte)(hash ^ (hash >> 8) ^ (hash >> 16) ^ (hash >> 24));
if (0 == key)
key = 0xD0;
for (int i = 0; i < count; ++i)
data[pos+i] ^= key;
}
public override void Encrypt (Xp3Entry entry, long offset, byte[] data, int pos, int count)
{
Decrypt (entry, offset, data, pos, count);
}
}
[Serializable]
public class HighRunningCrypt : ICrypt
{
public override void Decrypt (Xp3Entry entry, long offset, byte[] data, int pos, int count)
{
byte key = (byte)entry.Hash;
if (0 == key)
return;
for (int i = 0; i < count; ++i)
{
if ((offset + i) % key != 0)
data[pos+i] ^= key;
}
}
public override byte Decrypt (Xp3Entry entry, long offset, byte value)
{
byte key = (byte)entry.Hash;
return key != 0 && offset % key != 0 ? (byte)(value ^ key) : value;
}
public override void Encrypt (Xp3Entry entry, long offset, byte[] data, int pos, int count)
{
Decrypt (entry, offset, data, pos, count);
}
}
}