morkt 60dedf0328 NekoPack archives are actually hierarchical.
Instead of directory and file names, their hash sums are stored. Hash is
one-way function, so reconstructing names is impossible unless there's
some predefined set of widely-used names, like "script", "bgm" etc.
2015-03-26 06:52:45 +04:00

245 lines
9.9 KiB
C#

//! \file ArcNEKO.cs
//! \date Fri Mar 13 02:27:53 2015
//! \brief Nekopack archive format implementation.
//
// 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 GameRes.Utility;
namespace GameRes.Formats.Neko
{
public class NekoArchive : ArcFile
{
public uint Key { get; private set; }
public NekoArchive (ArcView arc, ArchiveFormat impl, ICollection<Entry> dir, uint key)
: base (arc, impl, dir)
{
Key = key;
}
}
[Export(typeof(ArchiveFormat))]
public class PakOpener : ArchiveFormat
{
public override string Tag { get { return "NEKO"; } }
public override string Description { get { return "NekoPack resource archive"; } }
public override uint Signature { get { return 0x4f4b454e; } } // "NEKO"
public override bool IsHierarchic { get { return true; } }
public override bool CanCreate { get { return false; } }
public PakOpener ()
{
Extensions = new string[] { "dat" };
}
public override ArcFile TryOpen (ArcView file)
{
if (!file.View.AsciiEqual (4, "PACK"))
return null;
uint id = file.View.ReadUInt32 (8);
int length;
byte[] index = ReadBlock (file.View, id, 0x10, out length);
int total = 0;
long offset = 0x18 + length;
var dir = new List<Entry>();
int index_pos = 0;
for (int remaining = length; remaining > 0;)
{
int count = LittleEndian.ToInt32 (index, index_pos+4);
if (count <= 0 || count > remaining/8-1)
return null;
uint hash = LittleEndian.ToUInt32 (index, index_pos);
total += count;
dir.Capacity = total;
index_pos += 8;
for (int j = 0; j < count; ++j)
{
var entry = new Entry
{ Offset = offset, Size = LittleEndian.ToUInt32 (index, index_pos+4) };
if (!entry.CheckPlacement (file.MaxOffset))
return null;
index_pos += 8;
offset += entry.Size + 8;
dir.Add (entry);
}
remaining -= 8 + count * 8;
}
int i = 0;
byte[] buffer = new byte[0x10];
foreach (var entry in dir)
{
file.View.Read (entry.Offset, buffer, 0, 0x10);
uint hash = LittleEndian.ToUInt32 (buffer, 0);
if (0 != hash)
{
ulong key = KeyFromHash (hash);
Decrypt (key, buffer, 8, 8);
}
uint signature = LittleEndian.ToUInt32 (buffer, 8);
var res = FormatCatalog.Instance.LookupSignature (signature);
string ext = "";
if (res.Any())
{
ext = res.First().Extensions.First();
entry.Type = res.First().Type;
}
else if (0x474e4d8a == signature)
ext = "mng";
if (!string.IsNullOrEmpty (ext))
entry.Name = string.Format ("{0:D4}.{1}", i, ext);
else
entry.Name = i.ToString ("D4");
++i;
}
return new NekoArchive (file, this, dir, id);
}
public override Stream OpenEntry (ArcFile arc, Entry entry)
{
var pak = arc as NekoArchive;
if (null == pak)
return arc.File.CreateStream (entry.Offset, entry.Size);
int length;
var data = ReadBlock (arc.File.View, pak.Key, entry.Offset, out length);
return new MemoryStream (data, 0, length, false);
}
static ulong KeyFromHash (uint hash)
{
uint v2 = hash ^ (hash + 1566083941u);
uint v3 = v2 ^ (hash - 899497514u);
ulong result = v3 ^ (v2 - 1894007588u);
return result | (result ^ (v3 + 1812433253u)) << 32;
}
static uint HashFromString (uint seed, byte[] str, int offset, int length)
{
// 0x00000000, "NEKOPACK" -> 0xAC0BF0B1
// 0xAC0BF0B1, "RBS0011" -> 0x9B75ADA7
uint result = seed;
for (int i = 0; i < length; ++i)
{
byte c = str[offset+i];
result += c + result * 37;
}
return result;
}
static uint HashFromName (uint seed, byte[] str, int offset, int length)
{
// 0x9B75ADA7, "script" -> 0x0DDB021E
// 0x9B75ADA7, "start.bin" -> 0xCB8FB53B
uint result = seed;
for (int i = 0; i < length; ++i)
{
byte c = str[offset+i];
result = 81 * (ShiftMap[c] ^ result);
}
return result;
}
static readonly byte[] ShiftMap = new byte[]
{
0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
0x38, 0x2F, 0x33, 0x3C, 0x40, 0x3B, 0x2A, 0x2E, 0x31, 0x30, 0x26, 0x44, 0x35, 0x28, 0x3E, 0x12,
0x02, 0x22, 0x06, 0x20, 0x1A, 0x1C, 0x0F, 0x11, 0x18, 0x17, 0x42, 0x2B, 0x3A, 0x37, 0x34, 0x0C,
0x41, 0x08, 0x1D, 0x07, 0x15, 0x21, 0x05, 0x1E, 0x0A, 0x14, 0x0E, 0x10, 0x09, 0x27, 0x1F, 0x0B,
0x23, 0x16, 0x0D, 0x01, 0x25, 0x04, 0x1B, 0x03, 0x13, 0x24, 0x19, 0x2D, 0x12, 0x29, 0x32, 0x3F,
0x3D, 0x08, 0x1D, 0x07, 0x15, 0x21, 0x05, 0x1E, 0x0A, 0x14, 0x0E, 0x10, 0x09, 0x27, 0x1F, 0x0B,
0x23, 0x16, 0x0D, 0x01, 0x25, 0x04, 0x1B, 0x03, 0x13, 0x24, 0x19, 0x2C, 0x39, 0x43, 0x36, 0x00,
0x4B, 0xA9, 0xA7, 0xAF, 0x50, 0x52, 0x91, 0x9F, 0x47, 0x6B, 0x96, 0xAB, 0x87, 0xB5, 0x9B, 0xBB,
0x99, 0xA4, 0xBF, 0x5C, 0xC6, 0x9C, 0xC2, 0xC4, 0xB6, 0x4F, 0xB8, 0xC1, 0x85, 0xA8, 0x51, 0x7E,
0x5F, 0x82, 0x73, 0xC7, 0x90, 0x4E, 0x45, 0xA5, 0x7A, 0x63, 0x70, 0xB3, 0x79, 0x83, 0x60, 0x55,
0x5B, 0x5E, 0x68, 0xBA, 0x53, 0xA1, 0x67, 0x97, 0xAC, 0x71, 0x81, 0x59, 0x64, 0x7C, 0x9D, 0xBD,
0x9D, 0xBD, 0x95, 0xA0, 0xB2, 0xC0, 0x6F, 0x6A, 0x54, 0xB9, 0x6D, 0x88, 0x77, 0x48, 0x5D, 0x72,
0x49, 0x93, 0x57, 0x65, 0xBE, 0x4A, 0x80, 0xA2, 0x5A, 0x98, 0xA6, 0x62, 0x7F, 0x84, 0x75, 0xBC,
0xAD, 0xB1, 0x6E, 0x76, 0x8B, 0x9E, 0x8C, 0x61, 0x69, 0x8D, 0xB4, 0x78, 0xAA, 0xAE, 0x8F, 0xC3,
0x58, 0xC5, 0x74, 0xB7, 0x8E, 0x7D, 0x89, 0x8A, 0x56, 0x4D, 0x86, 0x94, 0x9A, 0x4C, 0x92, 0xB0,
};
static uint CalcParity (uint a1, uint a2)
{
uint v1 = (a2 ^ ((a2 ^ ((a2 ^ ((a2 ^ a1) + 1566083941u)) - 899497514u)) - 1894007588u)) + 1812433253u;
int v2 = (int)(((a2 ^ ((a2 ^ a1) + 1566083941u)) - 899497514u) >> 27);
return v1 << v2 | v1 >> (32-v2);
}
static ulong Decrypt (ulong key, byte[] buf, int offset, int length)
{
unsafe
{
fixed (byte* data = buf)
{
ulong* first = (ulong*)(data + offset);
ulong* last = first + length/8;
while (first != last)
{
ulong v = *first ^ key;
key = _m_paddw (key, v);
*first++ = v;
}
return key;
}
}
}
static ulong _m_paddw (ulong x, ulong y)
{
ulong mask = 0xffff;
ulong r = ((x & mask) + (y & mask)) & mask;
mask <<= 16;
r |= ((x & mask) + (y & mask)) & mask;
mask <<= 16;
r |= ((x & mask) + (y & mask)) & mask;
mask <<= 16;
r |= ((x & mask) + (y & mask)) & mask;
return r;
}
static byte[] ReadBlock (ArcView.Frame view, uint id, long offset, out int length)
{
uint hash = view.ReadUInt32 (offset);
length = view.ReadInt32 (offset+4);
// parity check
// if (CalcParity (id, (uint)length) != hash)
// throw new InvalidFormatException();
int aligned_size = (length+7) & ~7;
byte[] buffer = new byte[aligned_size];
length = view.Read (offset+8, buffer, 0, (uint)length);
if (0 != hash)
{
ulong key = KeyFromHash (hash);
Decrypt (key, buffer, 0, aligned_size);
}
return buffer;
}
}
}