376 lines
13 KiB
C#

//! \file YuzCrypt.cs
//! \date 2018 Apr 01
//! \brief YuzuSoft KiriKiri encryption schemes.
//
// Copyright (C) 2018 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.IO;
using System.Text;
using GameRes.Compression;
using GameRes.Utility;
namespace GameRes.Formats.KiriKiri
{
[Serializable]
public class SenrenCxCrypt : CxEncryption
{
public SenrenCxCrypt (CxScheme scheme) : base (scheme)
{
}
public virtual string NamesSectionId { get { return "sen:"; } }
internal virtual void ReadYuzNames (byte[] yuz, FilenameMap filename_map)
{
using (var ystream = new MemoryStream (yuz))
using (var zstream = ZLibCompressor.DeCompress (ystream))
using (var input = new BinaryReader (zstream, Encoding.Unicode))
{
long dir_offset = 0;
while (-1 != input.PeekChar())
{
uint entry_signature = input.ReadUInt32();
long entry_size = input.ReadInt64();
if (entry_size < 0)
return;
dir_offset += 12 + entry_size;
uint hash = input.ReadUInt32();
int name_size = input.ReadInt16();
if (name_size > 0)
{
entry_size -= 6;
if (name_size * 2 <= entry_size)
{
var filename = new string (input.ReadChars (name_size));
filename_map.Add (hash, filename);
}
}
input.BaseStream.Position = dir_offset;
}
filename_map.AddShortcut ("$", "startup.tjs");
}
}
}
[Serializable]
public class CabbageCxCrypt : SenrenCxCrypt
{
uint m_random_seed;
public CabbageCxCrypt (CxScheme scheme, uint seed) : base (scheme)
{
m_random_seed = seed;
}
public override string NamesSectionId { get { return "cbg:"; } }
internal override CxProgram NewProgram (uint seed)
{
return new CxProgramNana (seed, m_random_seed, ControlBlock);
}
}
[Serializable]
public class NanaCxCrypt : CabbageCxCrypt
{
public uint[] YuzKey;
public NanaCxCrypt (CxScheme scheme, uint seed) : base (scheme, seed)
{
}
public override string NamesSectionId { get { return "dls:"; } }
internal override void ReadYuzNames (byte[] yuz, FilenameMap filename_map)
{
if (null == YuzKey)
throw new InvalidEncryptionScheme();
var decryptor = CreateNameListDecryptor();
decryptor.Decrypt (yuz, Math.Min (yuz.Length, 0x100));
base.ReadYuzNames (yuz, filename_map);
}
internal virtual INameListDecryptor CreateNameListDecryptor ()
{
return new NanaDecryptor (YuzKey, YuzKey[4], YuzKey[5]);
}
}
[Serializable]
public class RiddleCxCrypt : NanaCxCrypt
{
public uint m_key1 = 0xAAAAAAAA;
public uint m_key2 = 0x55555555;
public RiddleCxCrypt (CxScheme scheme, uint seed) : base (scheme, seed)
{
}
public override string NamesSectionId { get { return "yuz:"; } }
public override void Decrypt (Xp3Entry entry, long offset, byte[] buffer, int pos, int count)
{
ProcessFirstBytes (entry, offset, buffer, pos, count);
base.Decrypt (entry, offset, buffer, pos, count);
}
public override void Encrypt (Xp3Entry entry, long offset, byte[] buffer, int pos, int count)
{
base.Encrypt (entry, offset, buffer, pos, count);
ProcessFirstBytes (entry, offset, buffer, pos, count);
}
public override byte Decrypt (Xp3Entry entry, long offset, byte value)
{
if (offset < 8)
{
var buffer = new byte[1] { value };
this.Decrypt (entry, offset, buffer, 0, 1);
return buffer[0];
}
else
{
return base.Decrypt (entry, offset, value);
}
}
internal void ProcessFirstBytes (Xp3Entry entry, long offset, byte[] buffer, int pos, int count)
{
if (offset < 8 && count > 0)
{
ulong key = GetKeyFromHash (entry.Hash);
key >>= (int)offset << 3;
int first_chunk = Math.Min (count, 8 - (int)offset);
for (int i = 0; i < first_chunk; ++i)
{
buffer[pos+i] ^= (byte)key;
key >>= 8;
}
}
}
internal virtual ulong GetKeyFromHash (uint hash)
{
uint lo = hash ^ m_key2;
uint hi = (hash << 13) ^ hash;
hi ^= hi >> 17;
hi ^= (hi << 5) ^ m_key1;
return (ulong)hi << 32 | lo;
}
internal override INameListDecryptor CreateNameListDecryptor ()
{
return new YuzDecryptor (ControlBlock, YuzKey, YuzKey[4], YuzKey[5]);
}
}
internal interface INameListDecryptor
{
void Decrypt (byte[] data, int length);
}
internal class YuzDecryptor : INameListDecryptor
{
byte[] m_state;
public YuzDecryptor (uint[] key1, uint[] key2, uint seed1, uint seed2)
{
m_state = new byte[64];
Buffer.BlockCopy (key2, 0, m_state, 0, 16);
Buffer.BlockCopy (key1, 0, m_state, 16, 32);
LittleEndian.Pack (~0, m_state, 48);
LittleEndian.Pack (~0, m_state, 52);
LittleEndian.Pack (~seed1, m_state, 56);
LittleEndian.Pack (~seed2, m_state, 60);
}
public void Decrypt (byte[] data, int length)
{
var state1 = new byte[64];
var state2 = new byte[64];
int i = 0;
ulong offset = 0;
while (length > 0)
{
Buffer.BlockCopy (m_state, 0, state1, 0, 64);
LittleEndian.Pack (~offset++, state1, 48);
TransformState (state1, state2, 8);
int count = Math.Min (0x40, length);
for (int j = 0; j < count; ++j)
{
data[i++] ^= state2[j];
}
length -= count;
}
}
uint[] tmp = new uint[16];
void TransformState (byte[] state1, byte[] target, int length)
{
for (int i = 0; i < 16; ++i)
{
tmp[i] = ~LittleEndian.ToUInt32 (state1, i * 4);
}
if (length > 0)
{
for (int count = ((length - 1) >> 1) + 1; count > 0; --count)
{
uint t1 = tmp[4] + tmp[0];
uint t2 = Binary.RotL (t1 ^ tmp[12], 16);
uint t3 = t2 + tmp[8];
uint t4 = Binary.RotL (tmp[4] ^ t3, 12);
uint t5 = t4 + t1;
uint t6 = Binary.RotL (t5 ^ t2, 8);
tmp[12] = t6;
t6 += t3;
tmp[4] = Binary.RotL (t4 ^ t6, 7);
t4 = Binary.RotL ((tmp[5] + tmp[1]) ^ tmp[13], 16);
t3 = Binary.RotL (tmp[5] ^ (t4 + tmp[9]), 12);
t2 = t3 + tmp[5] + tmp[1];
tmp[13] = Binary.RotL (t2 ^ t4, 8);
tmp[9] += tmp[13] + t4;
tmp[5] = Binary.RotL (t3 ^ tmp[9], 7);
t4 = Binary.RotL ((tmp[6] + tmp[2]) ^ tmp[14], 16);
tmp[10] += t4;
t1 = Binary.RotL (tmp[6] ^ tmp[10], 12);
t3 = t1 + tmp[6] + tmp[2];
tmp[14] = Binary.RotL (t3 ^ t4, 8);
tmp[6] = Binary.RotL (t1 ^ (tmp[14] + tmp[10]), 7);
tmp[10] += tmp[14];
t4 = (tmp[7] + tmp[3]) ^ tmp[15];
tmp[3] += tmp[7];
t4 = Binary.RotL (t4, 16);
tmp[11] += t4;
t1 = Binary.RotL (tmp[7] ^ tmp[11], 12);
t4 ^= t1 + tmp[3];
tmp[3] += t1;
t4 = Binary.RotL (t4, 8);
tmp[11] += t4;
t1 = Binary.RotL (t1 ^ tmp[11], 7);
t5 += tmp[5];
t2 += tmp[6];
t4 = Binary.RotL (t5 ^ t4, 16);
tmp[10] += t4;
tmp[5] = Binary.RotL (tmp[5] ^ tmp[10], 12);
tmp[0] = tmp[5] + t5;
t4 = Binary.RotL (tmp[0] ^ t4, 8);
tmp[15] = t4;
tmp[10] += t4;
tmp[5] = Binary.RotL (tmp[5] ^ tmp[10], 7);
tmp[12] = Binary.RotL (tmp[12] ^ t2, 16);
tmp[11] += tmp[12];
t4 = Binary.RotL (tmp[11] ^ tmp[6], 12);
tmp[1] = t4 + t2;
tmp[12] = Binary.RotL (tmp[12] ^ tmp[1], 8);
tmp[11] += tmp[12];
tmp[6] = Binary.RotL (t4 ^ tmp[11], 7);
t3 += t1;
t4 = Binary.RotL (tmp[13] ^ t3, 16);
t2 = t4 + t6;
t1 = Binary.RotL (t2 ^ t1, 12);
tmp[2] = t1 + t3;
tmp[13] = Binary.RotL (t4 ^ tmp[2], 8);
tmp[8] = tmp[13] + t2;
tmp[7] = Binary.RotL (tmp[8] ^ t1, 7);
t6 = Binary.RotL (tmp[14] ^ (tmp[4] + tmp[3]), 16);
t1 = Binary.RotL (tmp[4] ^ (t6 + tmp[9]), 12);
tmp[3] += t1 + tmp[4];
t3 = Binary.RotL (t6 ^ tmp[3], 8);
tmp[9] += t3 + t6;
tmp[4] = Binary.RotL (t1 ^ tmp[9], 7);
tmp[14] = t3;
}
}
int pos = 0;
for (int i = 0; i < 16; ++i)
{
uint x = tmp[i] + ~LittleEndian.ToUInt32 (state1, pos);
LittleEndian.Pack (x, target, pos);
pos += 4;
}
}
}
internal class NanaDecryptor : INameListDecryptor
{
uint[] m_state;
ulong m_seed;
public NanaDecryptor (uint[] key, uint seed1, uint seed2)
{
m_state = new uint[27];
m_seed = (ulong)seed2 << 32 | seed1;
var s = new uint[3];
uint k = key[0];
s[0] = key[1];
s[1] = key[2];
s[2] = key[3];
m_state[0] = k;
int dst = 1;
for (uint i = 0; i < 26; ++i)
{
int src = (int)i % 3;
uint m = Binary.RotR (s[src], 8);
uint n = i ^ (k + m);
k = n ^ Binary.RotL (k, 3);
m_state[dst++] = k;
s[src] = n;
}
}
public void Decrypt (byte[] data, int length)
{
int i = 0;
ulong offset = 0;
while (length > 0)
{
ulong key = ++offset ^ m_seed;
key = TransformKey (key);
int count = Math.Min (8, length);
for (int j = 0; j < count; ++j)
{
data[i++] ^= (byte)key;
key >>= 8;
}
length -= count;
}
}
ulong TransformKey (ulong key)
{
uint lo = (uint)key;
uint hi = (uint)(key >> 32);
for (int i = 0; i < 27; ++i)
{
hi = Binary.RotR (hi, 8);
hi += lo;
hi ^= m_state[i];
lo = Binary.RotL (lo, 3);
lo ^= hi;
}
return (ulong)hi << 32 | lo;
}
}
}