313 lines
11 KiB
C#

//! \file ArcAFA.cs
//! \date Mon Apr 25 18:18:57 2016
//! \brief AliceSoft System 4 engine resource archive.
//
// Copyright (C) 2016-2018 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.Collections.Generic;
using System.ComponentModel.Composition;
using System.IO;
using GameRes.Compression;
namespace GameRes.Formats.AliceSoft
{
[Export(typeof(ArchiveFormat))]
public class AfaOpener : ArchiveFormat
{
public override string Tag { get { return "AFA"; } }
public override string Description { get { return "AliceSoft System 4 resource archive"; } }
public override uint Signature { get { return 0x48414641; } } // 'AFAH'
public override bool IsHierarchic { get { return true; } }
public override bool CanWrite { get { return false; } }
public override ArcFile TryOpen (ArcView file)
{
if (!file.View.AsciiEqual (8, "AlicArch"))
return TryOpenV3 (file);
if (!file.View.AsciiEqual (0x1C, "INFO"))
return null;
int version = file.View.ReadInt32 (0x10);
long base_offset = file.View.ReadUInt32 (0x18);
uint packed_size = file.View.ReadUInt32 (0x20);
int unpacked_size = file.View.ReadInt32 (0x24);
int count = file.View.ReadInt32 (0x28);
if (!IsSaneCount (count))
return null;
var dir = new List<Entry> (count);
var name_buf = new byte[0x40];
using (var input = file.CreateStream (0x2C, packed_size))
using (var zstream = new ZLibStream (input, CompressionMode.Decompress))
using (var index = new BinaryReader (zstream))
{
for (int i = 0; i < count; ++i)
{
int name_length = index.ReadInt32();
int index_step = index.ReadInt32();
if (name_length <= 0 || name_length > index_step || index_step > unpacked_size)
return null;
if (index_step > name_buf.Length)
name_buf = new byte[index_step];
if (index_step != index.Read (name_buf, 0, index_step))
return null;
var name = Encodings.cp932.GetString (name_buf, 0, name_length);
var entry = FormatCatalog.Instance.Create<Entry> (name);
index.ReadInt32();
index.ReadInt32();
if (version < 2)
index.ReadInt32();
entry.Offset = index.ReadUInt32() + base_offset;
entry.Size = index.ReadUInt32();
if (!entry.CheckPlacement (file.MaxOffset))
return null;
dir.Add (entry);
}
return new ArcFile (file, this, dir);
}
}
internal ArcFile TryOpenV3 (ArcView file)
{
if (file.View.ReadInt32 (8) != 3)
return null;
uint index_size = file.View.ReadUInt32 (4);
var index = new AfaIndexReader (file, index_size);
var dir = index.Read();
if (null == dir || 0 == dir.Count)
return null;
return new ArcFile (file, this, dir);
}
static readonly byte[] AffKey = {
0xC8, 0xBB, 0x8F, 0xB7, 0xED, 0x43, 0x99, 0x4A,
0xA2, 0x7E, 0x5B, 0xB0, 0x68, 0x18, 0xF8, 0x88
};
public override Stream OpenEntry (ArcFile arc, Entry entry)
{
if (entry.Size <= 0x10 || !arc.File.View.AsciiEqual (entry.Offset, "AFF\0"))
return base.OpenEntry (arc, entry);
uint data_size = entry.Size - 0x10u;
uint encrypted_length = Math.Min (0x40u, data_size);
var prefix = arc.File.View.ReadBytes (entry.Offset+0x10, encrypted_length);
for (int i = 0; i < prefix.Length; ++i)
prefix[i] ^= AffKey[i & 0xF];
if (data_size <= 0x40)
return new BinMemoryStream (prefix, entry.Name);
var rest = arc.File.CreateStream (entry.Offset+0x10+encrypted_length, data_size-encrypted_length);
return new PrefixStream (prefix, rest);
}
}
internal sealed class AfaIndexReader
{
ArcView m_file;
uint m_data_offset;
byte[] m_dict;
public AfaIndexReader (ArcView file, uint index_size)
{
m_file = file;
m_data_offset = index_size + 8;
}
public List<Entry> Read ()
{
byte[] packed;
using (var input = m_file.CreateStream (12, m_data_offset-12))
using (var bits = new MsbBitStream (input))
{
bits.GetNextBit();
m_dict = ReadBytes (bits);
if (null == m_dict)
return null;
int packed_size = ReadInt32 (bits);
int unpacked_size = ReadInt32 (bits);
packed = new byte[packed_size];
for (int i = 0; i < packed_size; ++i)
{
packed[i] = (byte)bits.GetBits (8);
}
}
using (var bstr = new BinMemoryStream (packed))
using (var zstr = new ZLibStream (bstr, CompressionMode.Decompress))
using (var index = new MsbBitStream (zstr))
{
index.GetNextBit();
int count = ReadInt32 (index);
if (!ArchiveFormat.IsSaneCount (count))
return null;
var dir = new List<Entry> (count);
for (int i = 0; i < count; ++i)
{
if (index.GetBits (2) == -1)
break;
var name_buf = ReadEncryptedChars (index);
if (null == name_buf)
return null;
var name = DecryptString (name_buf, name_buf.Length);
var entry = FormatCatalog.Instance.Create<Entry> (name);
ReadInt32 (index);
ReadInt32 (index);
entry.Offset = (uint)ReadInt32 (index) + m_data_offset;
entry.Size = (uint)ReadInt32 (index);
if (!entry.CheckPlacement (m_file.MaxOffset))
return null;
dir.Add (entry);
}
return dir;
}
}
byte[] ReadBytes (MsbBitStream input)
{
int buf_size = ReadInt32 (input);
var buf = new byte[buf_size];
int dst = 0;
var rnd = new RandomGenerator ((uint)buf_size);
while (dst < buf_size)
{
int count = (int)rnd.GetNext() & 3;
int skipped = input.GetBits (count + 1);
if (-1 == skipped)
return null;
rnd.GetNext();
int v = input.GetBits (8);
if (-1 == v)
return null;
buf[dst++] = (byte)v;
}
return buf;
}
ushort[] ReadEncryptedChars (MsbBitStream input)
{
int buf_size = ReadInt32 (input);
var buf = new ushort[buf_size];
int dst = 0;
var rnd = new RandomGenerator ((uint)buf_size);
while (dst < buf_size)
{
int count = (int)rnd.GetNext() & 3;
int skipped = input.GetBits (count + 1);
if (-1 == skipped)
return null;
rnd.GetNext();
int lo = input.GetBits (8);
int hi = input.GetBits (8);
if (-1 == lo || -1 == hi)
return null;
buf[dst++] = (ushort)(lo | hi << 8);
}
return buf;
}
byte[] m_string_buf = new byte[0x100];
string DecryptString (ushort[] input, int input_length)
{
if (m_string_buf.Length < input_length)
m_string_buf = new byte[input_length];
for (int i = 0; i < input_length; ++i)
{
m_string_buf[i] = (byte)(m_dict[input[i]] ^ 0xA4);
}
return Encodings.cp932.GetString (m_string_buf, 0, input_length);
}
static int ReadInt32 (MsbBitStream input)
{
int b0 = input.GetBits (8);
int b1 = input.GetBits (8);
int b2 = input.GetBits (8);
int b3 = input.GetBits (8);
return b3 << 24 | b2 << 16 | b1 << 8 | b0;
}
}
internal class RandomGenerator
{
uint[] m_state = new uint[521];
int m_current;
public RandomGenerator (uint seed)
{
Init (seed);
}
public void Init (uint seed)
{
uint val = 0;
for (int i = 0; i < 17; ++i)
{
for (int j = 0; j < 32; ++j)
{
seed = 1566083941u * seed + 1;
val = seed & 0x80000000 | (val >> 1);
}
m_state[i] = val;
}
m_state[16] = m_state[15] ^ (m_state[0] >> 9) ^ (m_state[16] << 23);
for (int i = 17; i < 521; ++i)
{
m_state[i] = m_state[i-1] ^ (m_state[i-16] >> 9) ^ (m_state[i-17] << 23);
}
Shuffle();
Shuffle();
Shuffle();
Shuffle();
m_current = -1;
}
public uint GetNext ()
{
++m_current;
if (m_current >= 521)
{
Shuffle();
m_current = 0;
}
return m_state[m_current];
}
void Shuffle ()
{
for (int i = 0; i < 32; i += 4)
{
m_state[i ] ^= m_state[i + 489];
m_state[i+1] ^= m_state[i + 490];
m_state[i+2] ^= m_state[i + 491];
m_state[i+3] ^= m_state[i + 492];
}
for (int i = 32; i < 521; i += 3)
{
m_state[i ] ^= m_state[i - 32];
m_state[i+1] ^= m_state[i - 31];
m_state[i+2] ^= m_state[i - 30];
}
}
}
}