252 lines
9.6 KiB
C#

//! \file ArcSX.cs
//! \date 2022 Apr 29
//! \brief SakanaGL resource archive implementation.
//
// Copyright (C) 2022 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 GameRes.Utility;
using System;
using System.Collections.Generic;
using System.ComponentModel.Composition;
using System.IO;
using System.Linq;
using System.Text;
using System.Text.RegularExpressions;
namespace GameRes.Formats.Sakana
{
internal class SxEntry : PackedEntry
{
public ushort Flags;
public ushort ArcIndex;
public bool IsEncrypted { get { return 0 == (Flags & 0x10); } }
}
[Export(typeof(ArchiveFormat))]
public class SxOpener : ArchiveFormat
{
public override string Tag { get { return "SXSTORAGE"; } }
public override string Description { get { return "SakanaGL engine resource archive"; } }
public override uint Signature { get { return 0; } }
public override bool IsHierarchic { get { return true; } }
public override bool CanWrite { get { return false; } }
const uint DefaultKey = 0x2E76034B;
static readonly Regex ArchiveNameRe = new Regex (@"^(.*)-([^-]+)$");
public override ArcFile TryOpen (ArcView file)
{
var base_name = Path.GetFileNameWithoutExtension (file.Name);
var sx_name = base_name.Substring (0, 4) + "(00).sx";
sx_name = VFS.ChangeFileName (file.Name, sx_name);
if (!VFS.FileExists (sx_name))
{
var match = ArchiveNameRe.Match (base_name);
if (!match.Success)
return null;
sx_name = VFS.ChangeFileName (file.Name, match.Groups[1] + "(00).sx");
if (!VFS.FileExists (sx_name))
return null;
}
if (file.Name.Equals (sx_name, StringComparison.OrdinalIgnoreCase))
return null;
byte[] index_data;
using (var sx = VFS.OpenView (sx_name))
{
if (sx.MaxOffset <= 0x10)
return null;
if (!sx.View.AsciiEqual (0, "SSXXDEFL"))
return null;
int key = Binary.BigEndian (sx.View.ReadInt32 (8));
int length = (int)(sx.MaxOffset - 0x10);
var index_packed = sx.View.ReadBytes (0x10, (uint)length);
long lkey = (long)key + length;
lkey = key ^ (961 * lkey - 124789) ^ DefaultKey;
uint key_lo = (uint)lkey;
uint key_hi = (uint)(lkey >> 32) ^ 0x2E6;
DecryptData (index_packed, key_lo, key_hi);
index_data = UnpackZstd (index_packed);
}
using (var index = new BinMemoryStream (index_data))
{
var reader = new SxIndexDeserializer (index, file.MaxOffset);
var dir = reader.Deserialize();
if (null == dir || dir.Count == 0)
return null;
return new ArcFile (file, this, dir);
}
}
public override Stream OpenEntry (ArcFile arc, Entry entry)
{
var sx_entry = entry as SxEntry;
if (null == sx_entry || (!sx_entry.IsEncrypted && !sx_entry.IsPacked))
return base.OpenEntry (arc, entry);
var input = arc.File.View.ReadBytes (entry.Offset, entry.Size);
if (sx_entry.IsEncrypted)
{
uint key_lo = (uint)(entry.Offset >> 4) ^ (entry.Size << 16) ^ DefaultKey;
uint key_hi = (entry.Size >> 16) ^ 0x2E6;
DecryptData (input, key_lo, key_hi);
}
if (sx_entry.IsPacked)
{
input = UnpackZstd (input);
if (sx_entry.UnpackedSize == 0)
sx_entry.UnpackedSize = (uint)input.Length;
}
return new BinMemoryStream (input, entry.Name);
}
internal static byte[] UnpackZstd (byte[] data)
{
int unpacked_size = BigEndian.ToInt32 (data, 0);
using (var dec = new ZstdNet.Decompressor())
{
var packed = new ArraySegment<byte> (data, 4, data.Length - 4);
return dec.Unwrap (packed, unpacked_size);
}
}
internal static void DecryptData (byte[] data, uint key_lo, uint key_hi)
{
if (data.Length < 4)
return;
key_lo ^= 0x159A55E5;
key_hi ^= 0x075BCD15;
uint v1 = key_hi ^ (key_hi << 11) ^ ((key_hi ^ (key_hi << 11)) >> 8) ^ 0x549139A;
uint v2 = v1 ^ key_lo ^ (key_lo << 11) ^ ((key_lo ^ (key_lo << 11) ^ (v1 >> 11)) >> 8);
uint v3 = v2 ^ (v2 >> 19) ^ 0x8E415C26;
uint v4 = v3 ^ (v3 >> 19) ^ 0x4D9D5BB8;
int count = data.Length / 4;
unsafe
{
fixed (byte* data_raw = data)
{
uint* data32 = (uint*)&data_raw[0];
for (int i = 0; i < count; ++i)
{
uint t1 = v4 ^ v1 ^ (v1 << 11) ^ ((v1 ^ (v1 << 11) ^ (v4 >> 11)) >> 8);
uint t2 = v2 ^ (v2 << 11);
v2 = v4;
v4 = t1 ^ t2 ^ ((t2 ^ (t1 >> 11)) >> 8);
data32[i] ^= (t1 >> 4) ^ (v4 << 12);
v1 = v3;
v3 = t1;
}
}
}
}
}
internal class SxIndexDeserializer
{
IBinaryStream m_index;
long m_max_offset;
string[] m_name_list;
List<Entry> m_dir;
public SxIndexDeserializer (IBinaryStream index, long max_offset)
{
m_index = index;
m_max_offset = max_offset;
}
public List<Entry> Deserialize ()
{
m_index.Position = 8;
int count = Binary.BigEndian (m_index.ReadInt32());
m_name_list = new string[count];
for (int i = 0; i < count; ++i)
{
int length = m_index.ReadUInt8();
m_name_list[i] = m_index.ReadCString (length, Encoding.UTF8);
}
count = Binary.BigEndian (m_index.ReadInt32());
m_dir = new List<Entry> (count);
for (int i = 0; i < count; ++i)
{
ushort arc = Binary.BigEndian (m_index.ReadUInt16());
ushort flags = Binary.BigEndian (m_index.ReadUInt16());
uint offset = Binary.BigEndian (m_index.ReadUInt32());
uint size = Binary.BigEndian (m_index.ReadUInt32());
var entry = new SxEntry {
Flags = flags,
Offset = (long)offset << 4,
Size = size,
IsPacked = 0 != (flags & 0x03),
ArcIndex = arc,
};
m_dir.Add (entry);
}
int arc_count = Binary.BigEndian (m_index.ReadUInt16());
int arc_index = -1;
for (int i = 0; i < arc_count; ++i)
{
m_index.ReadUInt32();
m_index.ReadUInt32();
m_index.ReadUInt32();
long arc_size = (long)Binary.BigEndian (m_index.ReadUInt32()) << 4; // archive body length
if (m_max_offset == arc_size)
arc_index = i;
m_index.ReadUInt64();
m_index.Seek (16, SeekOrigin.Current); // MD5 sum
}
count = Binary.BigEndian (m_index.ReadUInt16());
if (count > 0)
m_index.Seek (count * 24, SeekOrigin.Current);
DeserializeTree();
if (arc_count > 1 && arc_index != -1)
{
return m_dir.Where (e => (e as SxEntry).ArcIndex == arc_index).ToList();
}
return m_dir;
}
void DeserializeTree (string path = "")
{
int count = Binary.BigEndian (m_index.ReadUInt16());
int name_index = Binary.BigEndian (m_index.ReadInt32());
int file_index = Binary.BigEndian (m_index.ReadInt32());
var name = Path.Combine (path, m_name_list[name_index]);
if (-1 == file_index)
{
for (int i = 0; i < count; ++i)
{
DeserializeTree (name);
}
}
else
{
m_dir[file_index].Name = name;
m_dir[file_index].Type = FormatCatalog.Instance.GetTypeFromName (name);
}
}
}
}