GARbro-mirror/ArcFormats/Xuse/ArcWAG.cs
morkt 46dbf2b142 GameRes refactoring.
(FormatCatalog.CreateEntry): method renamed to 'Create' and made generic
towards Entry type.
2015-08-30 22:34:06 +04:00

239 lines
9.3 KiB
C#

//! \file ArcWAG.cs
//! \date Tue Aug 11 08:28:28 2015
//! \brief Xuse/Eternal resource archive.
//
// Copyright (C) 2015 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 System.Linq;
using System.Text.RegularExpressions;
using GameRes.Utility;
namespace GameRes.Formats.Xuse
{
internal class WagArchive : ArcFile
{
public readonly byte[] Key;
public WagArchive (ArcView arc, ArchiveFormat impl, ICollection<Entry> dir, byte[] key)
: base (arc, impl, dir)
{
Key = key;
}
}
[Export(typeof(ArchiveFormat))]
public class WagOpener : ArchiveFormat
{
public override string Tag { get { return "WAG"; } }
public override string Description { get { return "Xuse/Eternal resource archive"; } }
public override uint Signature { get { return 0x40474157; } } // 'WAG@'
public override bool IsHierarchic { get { return true; } }
public override bool CanCreate { get { return false; } }
public WagOpener ()
{
Extensions = new string[] { "wag", "4ag" };
Signatures = new uint[] { 0x40474157, 0x34464147 }; // 'GAF4'
}
public override ArcFile TryOpen (ArcView file)
{
if (0x0300 != file.View.ReadUInt16 (4))
return null;
int count = file.View.ReadInt32 (0x46);
if (!IsSaneCount (count))
return null;
byte[] title = new byte[0x40];
if (0x40 != file.View.Read (6, title, 0, 0x40))
return null;
int title_length = Array.IndexOf<byte> (title, 0);
if (-1 == title_length)
title_length = title.Length;
string arc_filename = Path.GetFileName (file.Name).ToLowerInvariant();
byte[] bin_filename = Encodings.cp932.GetBytes (arc_filename);
byte[] name_key = GenerateKey (bin_filename);
uint key_sum = (uint)name_key.Select (x => (int)x).Sum();
uint index_offset = 0x200 + key_sum;
for (int i = 0; i < name_key.Length; ++i)
{
index_offset ^= name_key[i];
index_offset = index_offset << 31 | index_offset >> 1;
}
for (int i = 0; i < name_key.Length; ++i)
{
index_offset ^= name_key[i];
index_offset = index_offset << 31 | index_offset >> 1;
}
index_offset %= 0x401;
index_offset += 0x4A;
byte[] index = new byte[4*count];
if (index.Length != file.View.Read (index_offset, index, 0, (uint)index.Length))
return null;
byte[] index_key = new byte[index.Length];
for (int i = 0; i < index_key.Length; ++i)
{
int v = name_key[(i+1) % name_key.Length] ^ (name_key[i % name_key.Length] + (i & 0xFF));
index_key[i] = (byte)(count + v);
}
Decrypt (index_offset, index_key, index);
var dir = new List<Entry> (count);
int current_offset = 0;
uint next_offset = LittleEndian.ToUInt32 (index, current_offset);
byte[] data_key = GenerateKey (title, 0, title_length);
string base_filename = Path.GetFileNameWithoutExtension (arc_filename);
byte[] chunk_buf = new byte[8];
byte[] filename_buf = new byte[0x40];
for (int i = 0; i < count; ++i)
{
current_offset += 4;
uint entry_offset = next_offset;
if (i + 1 == count)
next_offset = (uint)file.MaxOffset;
else
next_offset = LittleEndian.ToUInt32 (index, current_offset);
uint entry_size = next_offset - entry_offset;
if (8 != file.View.Read (entry_offset, chunk_buf, 0, 8))
return null;
Decrypt (entry_offset, data_key, chunk_buf);
if (!Binary.AsciiEqual (chunk_buf, "DSET"))
return null;
uint chunk_offset = entry_offset + 10;
int chunk_count = LittleEndian.ToInt32 (chunk_buf, 4);
string filename = null;
string type = null;
for (int chunk = 0; chunk < chunk_count; ++chunk)
{
if (8 != file.View.Read (chunk_offset, chunk_buf, 0, 8))
return null;
Decrypt (chunk_offset, data_key, chunk_buf);
int chunk_size = LittleEndian.ToInt32 (chunk_buf, 4);
if (chunk_size <= 0)
return null;
if (Binary.AsciiEqual (chunk_buf, "PICT"))
{
if (null == type)
{
type = "image";
entry_offset = chunk_offset + 0x10;
entry_size = (uint)chunk_size - 6;
}
}
else if (null == filename && Binary.AsciiEqual (chunk_buf, "FTAG"))
{
if (chunk_size > filename_buf.Length)
filename_buf = new byte[chunk_size];
if (chunk_size != file.View.Read (chunk_offset+10, filename_buf, 0, (uint)chunk_size))
return null;
Decrypt (chunk_offset+10, data_key, filename_buf, 0, chunk_size-2);
filename = Encodings.cp932.GetString (filename_buf, 0, chunk_size-2);
}
chunk_offset += 10 + (uint)chunk_size;
}
Entry entry;
if (!string.IsNullOrEmpty (filename))
{
filename = DriveRe.Replace (filename, "");
entry = FormatCatalog.Instance.Create<Entry> (filename);
}
else
{
entry = new Entry {
Name = string.Format ("{0}#{1:D4}", base_filename, i),
Type = type ?? ""
};
}
entry.Offset = entry_offset;
entry.Size = entry_size;
dir.Add (entry);
}
return new WagArchive (file, this, dir, data_key);
}
static readonly Regex DriveRe = new Regex (@"^(?:.+:)?\\+");
public override Stream OpenEntry (ArcFile arc, Entry entry)
{
var warc = arc as WagArchive;
if (null == warc)
return arc.File.CreateStream (entry.Offset, entry.Size);
var data = new byte[entry.Size];
arc.File.View.Read (entry.Offset, data, 0, entry.Size);
Decrypt ((uint)entry.Offset, warc.Key, data);
return new MemoryStream (data);
}
private byte[] GenerateKey (byte[] keyword)
{
return GenerateKey (keyword, 0, keyword.Length);
}
private byte[] GenerateKey (byte[] keyword, int index, int length)
{
uint hash = 0;
for (uint i = 0; i < length; ++i)
hash = ((keyword[i+index] + i) ^ hash) + (uint)length;
uint key_length = (hash & 0xFF) + 0x40;
for (int i = 0; i < length; ++i)
hash += keyword[i+index];
byte[] key = new byte[key_length--];
key[1] = (byte)(hash >> 8);
hash &= 0xF;
key[0] = (byte)hash;
key[2] = 0x46;
key[3] = 0x88;
for (uint i = 4; i < key_length; ++i)
{
hash += ((keyword[i % length] ^ hash) + i) & 0xFF;
key[i] = (byte)hash;
}
return key;
}
private void Decrypt (uint offset, byte[] key, byte[] index)
{
Decrypt (offset, key, index, 0, index.Length);
}
private void Decrypt (uint offset, byte[] key, byte[] index, int pos, int length)
{
uint key_last = (uint)key.Length-1;
for (uint i = 0; i < length; ++i)
index[pos+i] ^= key[(offset + i) % key_last];
}
}
}