2018-11-04 15:48:35 +04:00

414 lines
14 KiB
C#

//! \file ArcPAK.cs
//! \date 2018 Feb 27
//! \brief AGSI resource archive.
//
// 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.Collections.Generic;
using System.ComponentModel.Composition;
using System.Diagnostics;
using System.IO;
using System.Linq;
using System.Security.Cryptography;
using GameRes.Compression;
using GameRes.Cryptography;
using GameRes.Utility;
// Advanced Game Script Interpreter
namespace GameRes.Formats.FC01
{
internal class AgsiEntry : PackedEntry
{
public int Method;
public bool IsEncrypted { get { return Method >= 3 && (Method <= 5 || Method == 7); } }
public bool IsSpecial;
}
internal class AgsiArchive : ArcFile
{
public readonly byte[] Key;
public AgsiArchive (ArcView arc, ArchiveFormat impl, ICollection<Entry> dir, byte[] key)
: base (arc, impl, dir)
{
Key = key;
}
}
[Serializable]
public class AgsiScheme : ResourceScheme
{
public IDictionary<string, IDictionary<string, byte[]>> KnownSchemes;
};
[Export(typeof(ArchiveFormat))]
public class PakOpener : ArchiveFormat
{
public override string Tag { get { return "PAK/AGSI"; } }
public override string Description { get { return "AGSI engine resource archive"; } }
public override uint Signature { get { return 0x24A02028; } }
public override bool IsHierarchic { get { return false; } }
public override bool CanWrite { get { return false; } }
public PakOpener ()
{
Signatures = new uint[] { 0x4B434150, 0x24A02028, 0 }; // 'PACK'
}
public override ArcFile TryOpen (ArcView file)
{
var reader = IndexReader.Create (file);
if (null == reader)
return null;
var dir = reader.ReadIndex();
if (null == dir)
return null;
if (dir.Cast<AgsiEntry>().Any (e => e.IsEncrypted))
{
var scheme = QueryScheme (file);
if (null == scheme)
{
Trace.WriteLine ("Unknown AGSI encryption scheme", "[PAK/AGSI]");
return null;
}
var arc_name = Path.GetFileName (file.Name).ToLowerInvariant();
byte[] key;
if (scheme.TryGetValue (arc_name, out key) && key != null)
return new AgsiArchive (file, this, dir, key);
}
return new ArcFile (file, this, dir);
}
public override Stream OpenEntry (ArcFile arc, Entry entry)
{
var aent = (AgsiEntry)entry;
var aarc = arc as AgsiArchive;
Stream input;
if (!aent.IsEncrypted)
input = arc.File.CreateStream (entry.Offset, entry.Size);
else if (aarc != null && aarc.Key != null)
input = OpenEncryptedEntry (aarc, aent);
else
return base.OpenEntry (arc, entry);
switch (aent.Method)
{
case 0: // no compression
case 3:
break;
case 1: // RLE compression
case 4:
input = new PackedStream<RleDecompressor> (input, new RleDecompressor ((int)aent.UnpackedSize));
break;
case 2: // LZSS bit stream
case 5:
input = new PackedStream<LzBitStream> (input, new LzBitStream ((int)aent.UnpackedSize));
break;
case 6: // LZSS compression
case 7:
input = new LzssStream (input);
break;
}
return input;
}
internal Stream OpenEncryptedEntry (AgsiArchive arc, AgsiEntry entry)
{
uint enc_size = entry.Size;
if (enc_size > 1024)
{
enc_size = 1032;
}
using (var des = DES.Create())
{
des.Key = arc.Key;
des.Mode = CipherMode.ECB;
des.Padding = PaddingMode.Zeros;
using (var enc = arc.File.CreateStream (entry.Offset, enc_size))
using (var dec = new InputCryptoStream (enc, des.CreateDecryptor()))
{
var output = new byte[enc_size];
dec.Read (output, 0, output.Length);
int header_size;
if (!entry.IsSpecial)
{
header_size = output.ToInt32 (output.Length-4);
if (header_size > entry.UnpackedSize)
throw new InvalidEncryptionScheme();
}
else
header_size = (int)entry.UnpackedSize;
if (!entry.IsSpecial && entry.Size > enc_size)
{
var header = new byte[header_size];
Buffer.BlockCopy (output, 0, header, 0, header_size);
var input = arc.File.CreateStream (entry.Offset + enc_size, entry.Size - enc_size);
return new PrefixStream (header, input);
}
else
return new BinMemoryStream (output, 0, header_size, entry.Name);
}
}
}
protected IDictionary<string, byte[]> QueryScheme (ArcView file)
{
var title = FormatCatalog.Instance.LookupGame (file.Name, "*.sb")
?? FormatCatalog.Instance.LookupGame (file.Name, @"..\*.sb");
if (string.IsNullOrEmpty (title) || !KnownSchemes.ContainsKey (title))
return null;
return KnownSchemes[title];
}
static AgsiScheme DefaultScheme = new AgsiScheme
{
KnownSchemes = new Dictionary<string, IDictionary<string, byte[]>>()
};
public IDictionary<string, IDictionary<string, byte[]>> KnownSchemes
{
get { return DefaultScheme.KnownSchemes; }
}
public override ResourceScheme Scheme
{
get { return DefaultScheme; }
set { DefaultScheme = (AgsiScheme)value; }
}
}
internal class IndexReader
{
ArcView m_file;
int m_count;
int m_record_size;
uint m_data_offset;
public bool IsEncrypted { get; set; }
public IndexReader (ArcView file, int count, int record_size, bool is_encrypted)
{
m_file = file;
m_count = count;
m_record_size = record_size;
m_data_offset = (uint)(0xC + m_count * m_record_size);
IsEncrypted = is_encrypted;
}
public static IndexReader Create (ArcView file)
{
int count, record_size;
bool is_encrypted = false;
if (!file.View.AsciiEqual (0, "PACK"))
{
var header = file.View.ReadBytes (0, 12);
byte k1 = file.View.ReadByte (file.MaxOffset-9);
byte k2 = file.View.ReadByte (file.MaxOffset-6);
DecryptHeader (header, k1, k2);
if (!header.AsciiEqual ("PACK"))
return null;
count = header.ToInt32 (4);
record_size = header.ToInt32 (8);
is_encrypted = true;
}
else
{
count = file.View.ReadInt32 (4);
record_size = file.View.ReadInt32 (8);
}
if (!ArchiveFormat.IsSaneCount (count) || record_size <= 0x10 || record_size > 0x100)
return null;
var reader = new IndexReader (file, count, record_size, is_encrypted);
if (reader.m_data_offset >= file.MaxOffset)
return null;
return reader;
}
public List<Entry> ReadIndex ()
{
using (var index = OpenIndex())
{
int name_size = m_record_size - 0x10;
var dir = new List<Entry> (m_count);
for (int i = 0; i < m_count; ++i)
{
var entry = new AgsiEntry();
entry.UnpackedSize = index.ReadUInt32();
entry.Size = index.ReadUInt32();
entry.Method = index.ReadInt32();
entry.Offset = index.ReadUInt32() + m_data_offset;
if (!entry.CheckPlacement (m_file.MaxOffset))
return null;
var name = index.ReadCString (name_size);
if (string.IsNullOrEmpty (name))
return null;
entry.Name = name;
entry.Type = FormatCatalog.Instance.GetTypeFromName (name);
entry.IsPacked = entry.Method != 0 && entry.Method != 3;
entry.IsSpecial = name.Equals ("Copyright.Dat", StringComparison.OrdinalIgnoreCase);
dir.Add (entry);
}
return dir;
}
}
IBinaryStream OpenIndex ()
{
int index_size = m_count * m_record_size;
if (IsEncrypted)
{
var index = m_file.View.ReadBytes (12, (uint)index_size);
DecryptIndex (index, 0, index_size, 7524u);
return new BinMemoryStream (index);
}
else
return m_file.CreateStream (12, (uint)index_size);
}
static void DecryptHeader (byte[] header, byte k1, byte k2)
{
int shift = k2 & 7;
if (0 == shift)
shift = 1;
for (int i = 0; i < header.Length; ++i)
{
byte x = Binary.RotByteL (header[i], shift);
header[i] = (byte)(x ^ k1++);
}
}
static void DecryptIndex (byte[] data, int pos, int length, uint seed)
{
var rnd = new MersenneTwister (seed);
for (int i = 0; i < length; ++i)
{
uint key = rnd.Rand();
int shift = (int)key & 7;
if (0 == shift)
shift = 1;
byte x = Binary.RotByteL (data[pos+i], shift);
data[pos+i] = (byte)(key ^ x);
}
}
}
internal sealed class LzBitStream : Decompressor
{
MsbBitStream m_input;
int m_unpacked_size;
public LzBitStream ()
{
}
public LzBitStream (int unpacked_size)
{
m_unpacked_size = unpacked_size;
}
public override void Initialize (Stream input)
{
m_input = new MsbBitStream (input, true);
}
protected override IEnumerator<int> Unpack ()
{
var frame = new byte[0x1000];
int dst = 0;
int frame_pos = 1;
while (dst < m_unpacked_size)
{
int bit = m_input.GetNextBit();
if (bit != 0)
{
if (-1 == bit)
yield break;
int v = m_input.GetBits (8);
if (-1 == v)
yield break;
frame[frame_pos++ & 0xFFF] = m_buffer[m_pos++] = (byte)v;
dst++;
if (0 == --m_length)
yield return m_pos;
}
else
{
int offset = m_input.GetBits (12);
if (-1 == offset)
yield break;
int count = m_input.GetBits (4);
if (-1 == count)
yield break;
count += 2;
dst += count;
while (count --> 0)
{
byte v = frame[offset++ & 0xFFF];
frame[frame_pos++ & 0xFFF] = v;
m_buffer[m_pos++] = v;
if (0 == --m_length)
yield return m_pos;
}
}
}
}
bool m_disposed = false;
protected override void Dispose (bool disposing)
{
if (!m_disposed)
{
if (disposing)
{
m_input.Dispose();
m_disposed = true;
}
base.Dispose (disposing);
}
}
}
internal sealed class RleDecompressor : Decompressor
{
int m_unpacked_size;
public RleDecompressor ()
{
}
public RleDecompressor (int unpacked_size)
{
m_unpacked_size = unpacked_size;
}
public override void Initialize (Stream input)
{
}
protected override IEnumerator<int> Unpack ()
{
throw new NotImplementedException();
}
}
}