764 lines
31 KiB
C#

//! \file ArcNPA.cs
//! \date Fri Jul 18 04:07:42 2014
//! \brief NPA archive format implementation.
//
// Copyright (C) 2014 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.IO;
using System.Linq;
using System.Text;
using System.ComponentModel.Composition;
using System.Collections.Generic;
using System.Diagnostics;
using System.Runtime.InteropServices;
using ZLibNet;
using GameRes.Formats.Strings;
using GameRes.Formats.Properties;
namespace GameRes.Formats.NitroPlus
{
internal class NpaEntry : PackedEntry
{
public byte[] RawName;
public int FolderId;
}
internal class NpaArchive : ArcFile
{
public NpaTitleId GameId { get; private set; }
public int Key { get; private set; }
public byte[] KeyTable { get { return m_key_table.Value; } }
private Lazy<byte[]> m_key_table;
public NpaArchive (ArcView arc, ArchiveFormat impl, ICollection<Entry> dir,
NpaTitleId game_id, int key)
: base (arc, impl, dir)
{
GameId = game_id;
Key = key;
m_key_table = new Lazy<byte[]> (() => NpaOpener.GenerateKeyTable (game_id));
}
}
public enum NpaTitleId
{
NotEncrypted,
CHAOSHEAD, CHAOSHEADTR1, CHAOSHEADTR2, MURAMASATR, MURAMASA, SUMAGA, DJANGO, DJANGOTR,
LAMENTO, SWEETPOOL, SUMAGASP, DEMONBANE, MURAMASAAD, AXANAEL, KIKOKUGAI, SONICOMITR2,
SUMAGA3P, SONICOMI, LOSTX, LOSTXTRAILER, DRAMATICALMURDER, TOTONO, PHENOMENO, NEKODA,
}
public class NpaOptions : ResourceOptions
{
public NpaTitleId TitleId { get; set; }
public bool CompressContents { get; set; }
public int Key1 { get; set; }
public int Key2 { get; set; }
}
[Export(typeof(ArchiveFormat))]
public class NpaOpener : ArchiveFormat
{
public override string Tag { get { return "NPA"; } }
public override string Description { get { return arcStrings.NPADescription; } }
public override uint Signature { get { return 0x0141504e; } } // NPA\x01
public override bool IsHierarchic { get { return true; } }
public override bool CanCreate { get { return true; } }
/// <summary>
/// Known encryption schemes.
/// Order should match NpaTitleId enumeration.
/// </summary>
public static readonly string[] KnownSchemes = new string[] {
arcStrings.ArcNoEncryption,
"Chaos;Head", "Chaos;Head Trial 1", "Chaos;Head Trial 2", "Muramasa Trial", "Muramasa",
"Sumaga", "Zoku Satsuriku no Django", "Zoku Satsuriku no Django Trial", "Lamento",
"Sweet Pool", "Sumaga Special", "Demonbane", "MuramasaAD", "Axanael",
"Kikokugai", "Sonicomi Trial 2", "Sumaga 3% Trial", "Sonicomi Version 1.0",
"Guilty Crown Lost Xmas", "Guilty Crown Lost Xmas Trailer", "DRAMAtical Murder",
"Kimi to Kanojo to Kanojo no Koi", "Phenomeno", "Nekoda -Nyanda-",
};
public const int DefaultKey1 = 0x4147414e;
public const int DefaultKey2 = 0x21214f54;
public override ArcFile TryOpen (ArcView file)
{
int key1 = file.View.ReadInt32 (7);
int key2 = file.View.ReadInt32 (11);
bool compressed = 0 != file.View.ReadByte (15);
bool encrypted = 0 != file.View.ReadByte (16);
int total_count = file.View.ReadInt32 (17);
int folder_count = file.View.ReadInt32 (21);
int file_count = file.View.ReadInt32 (25);
if (total_count < folder_count + file_count)
return null;
uint dir_size = file.View.ReadUInt32 (37);
if (dir_size >= file.MaxOffset)
return null;
var game_id = NpaTitleId.NotEncrypted;
if (encrypted)
game_id = QueryGameEncryption();
int key = GetArchiveKey (game_id, key1, key2);
long cur_offset = 41;
var dir = new List<Entry> (file_count);
for (int i = 0; i < total_count; ++i)
{
int name_size = file.View.ReadInt32 (cur_offset);
if ((uint)name_size >= dir_size)
return null;
int type = file.View.ReadByte (cur_offset+4+name_size);
if (1 != type) // ignore directory entries
{
var raw_name = new byte[name_size];
file.View.Read (cur_offset+4, raw_name, 0, (uint)name_size);
for (int x = 0; x < name_size; ++x)
raw_name[x] += DecryptName (x, i, key);
var info_offset = cur_offset + 5 + name_size;
int id = file.View.ReadInt32 (info_offset);
uint offset = file.View.ReadUInt32 (info_offset+4);
uint size = file.View.ReadUInt32 (info_offset+8);
uint unpacked_size = file.View.ReadUInt32 (info_offset+12);
var entry = new NpaEntry {
Name = Encodings.cp932.GetString (raw_name),
Offset = dir_size+offset+41,
Size = size,
UnpackedSize = unpacked_size,
RawName = raw_name,
FolderId = id,
};
if (!entry.CheckPlacement (file.MaxOffset))
return null;
entry.Type = FormatCatalog.Instance.GetTypeFromName (entry.Name);
entry.IsPacked = compressed && entry.Type != "image";
dir.Add (entry);
}
cur_offset += 4 + name_size + 17;
}
if (game_id != NpaTitleId.NotEncrypted)
return new NpaArchive (file, this, dir, game_id, key);
else
return new ArcFile (file, this, dir);
}
public override void Create (Stream output, IEnumerable<Entry> list, ResourceOptions options,
EntryCallback callback)
{
var npa_options = GetOptions<NpaOptions> (options);
int callback_count = 0;
// build file index
var index = new Indexer (list, npa_options);
output.Position = 41 + index.Size;
long data_offset = 0;
// write files
foreach (var entry in index.Entries.Where (e => e.Type != "directory"))
{
if (data_offset > uint.MaxValue)
throw new FileSizeException();
if (null != callback)
callback (callback_count++, entry, arcStrings.MsgAddingFile);
using (var file = File.OpenRead (entry.Name))
{
var size = file.Length;
if (size > uint.MaxValue)
throw new FileSizeException();
entry.Offset = data_offset;
entry.UnpackedSize = (uint)size;
Stream destination = output;
if (NpaTitleId.NotEncrypted != npa_options.TitleId)
destination = new EncryptedStream (output, entry, npa_options.TitleId, index.Key);
try
{
if (entry.IsPacked)
{
using (var zstream = new ZLibStream (destination, CompressionMode.Compress,
CompressionLevel.Level9, true))
{
file.CopyTo (zstream);
zstream.Flush();
entry.Size = (uint)zstream.TotalOut;
}
}
else
{
file.CopyTo (destination);
entry.Size = entry.UnpackedSize;
}
}
finally
{
if (destination is EncryptedStream)
destination.Dispose();
}
data_offset += entry.Size;
}
}
if (null != callback)
callback (callback_count++, null, arcStrings.MsgWritingIndex);
output.Position = 0;
using (var header = new BinaryWriter (output, Encoding.ASCII, true))
{
header.Write (Signature);
header.Write ((short)0);
header.Write ((byte)0);
header.Write (npa_options.Key1);
header.Write (npa_options.Key2);
header.Write (npa_options.CompressContents);
header.Write (npa_options.TitleId != NpaTitleId.NotEncrypted);
header.Write (index.TotalCount);
header.Write (index.FolderCount);
header.Write (index.FileCount);
header.Write ((long)0);
header.Write (index.Size);
int entry_number = 0;
foreach (var entry in index.Entries)
{
header.Write (entry.RawName.Length);
for (int i = 0; i < entry.RawName.Length; ++i)
{
header.Write ((byte)(entry.RawName[i] - DecryptName (i, entry_number, index.Key)));
}
header.Write ((byte)("directory" == entry.Type ? 1 : 2));
header.Write (entry.FolderId);
header.Write ((uint)entry.Offset);
header.Write (entry.Size);
header.Write (entry.UnpackedSize);
++entry_number;
}
}
}
public override Stream OpenEntry (ArcFile arc, Entry entry)
{
Stream input;
if (arc is NpaArchive && entry is NpaEntry)
input = new EncryptedStream (arc as NpaArchive, entry as NpaEntry);
else
input = arc.File.CreateStream (entry.Offset, entry.Size);
return UnpackEntry (input, entry as PackedEntry);
}
private Stream UnpackEntry (Stream input, PackedEntry entry)
{
if (null != entry && entry.IsPacked)
return new ZLibStream (input, CompressionMode.Decompress);
return input;
}
internal static byte DecryptName (int index, int curfile, int arc_key)
{
int key = 0xFC*index;
key -= arc_key >> 0x18;
key -= arc_key >> 0x10;
key -= arc_key >> 0x08;
key -= arc_key & 0xff;
key -= curfile >> 0x18;
key -= curfile >> 0x10;
key -= curfile >> 0x08;
key -= curfile;
return (byte)(key & 0xff);
}
internal static int GetArchiveKey (NpaTitleId game_id, int key1, int key2)
{
if (NpaTitleId.LAMENTO == game_id)
return key1 + key2;
else
return key1 * key2;
}
internal static byte GetKeyFromEntry (NpaEntry entry, NpaTitleId game_id, int arc_key)
{
int key;
switch (game_id)
{
case NpaTitleId.AXANAEL:
case NpaTitleId.KIKOKUGAI:
case NpaTitleId.SONICOMITR2:
case NpaTitleId.SONICOMI:
case NpaTitleId.LOSTX:
case NpaTitleId.DRAMATICALMURDER:
case NpaTitleId.PHENOMENO:
key = 0x20101118;
break;
case NpaTitleId.TOTONO:
key = 0x12345678;
break;
default:
key = unchecked((int)0x87654321);
break;
}
var name = entry.RawName;
for (int i = 0; i < name.Length; ++i)
key -= name[i];
key *= name.Length;
if (game_id != NpaTitleId.LAMENTO) // if the game is not Lamento
{
key += arc_key;
key *= (int)entry.UnpackedSize;
}
return (byte)key;
}
public static byte[] GenerateKeyTable (NpaTitleId title_id)
{
int index = (int)title_id;
if (index < 0 || index >= OrderTable.Length)
throw new ArgumentOutOfRangeException ("title_id", "Invalid title id specified");
byte[] order = OrderTable[index];
if (null == order)
throw new ArgumentException ("Encryption key table not defined", "title_id");
var table = new byte[256];
for (int i = 0; i < 256; ++i)
{
int edx = i << 4;
int dl = (edx + order[i & 0x0f]) & 0xff;
int dh = (edx + (order[i>>4] << 8)) & 0xff00;
edx = (dh | dl) >> 4;
var eax = BaseTable[i];
table[eax] = (byte)(edx & 0xff);
}
for (int i = 17; i < order.Length; i+=2)
{
int ecx = order[i-1];
int edx = order[i];
byte tmp = table[ecx];
table[ecx] = table[edx];
table[edx] = tmp;
}
if (NpaTitleId.TOTONO == title_id)
{
var totono_table = new byte[256];
for (int i = 0; i < 256; ++i)
{
byte r = table[i];
r = table[r];
r = table[r];
totono_table[i] = (byte)~r;
}
table = totono_table;
}
return table;
}
public override ResourceOptions GetDefaultOptions ()
{
return new NpaOptions {
TitleId = GetTitleId (Settings.Default.NPAScheme),
CompressContents = Settings.Default.NPACompressContents,
Key1 = (int)Settings.Default.NPAKey1,
Key2 = (int)Settings.Default.NPAKey2,
};
}
public override object GetAccessWidget ()
{
return new GUI.WidgetNPA();
}
public override object GetCreationWidget ()
{
return new GUI.CreateNPAWidget();
}
NpaTitleId QueryGameEncryption ()
{
var options = Query<NpaOptions> (arcStrings.ArcEncryptedNotice);
return options.TitleId;
}
public static NpaTitleId GetTitleId (string title)
{
Debug.Assert (KnownSchemes.Length == OrderTable.Length,
"Number of known encryptions schemes does not match available order tables.");
var index = Array.IndexOf (KnownSchemes, title);
if (index != -1)
return (NpaTitleId)index;
else
return NpaTitleId.NotEncrypted;
}
static readonly byte[] BaseTable = {
0x6F,0x05,0x6A,0xBF,0xA1,0xC7,0x8E,0xFB,0xD4,0x2F,0x80,0x58,0x4A,0x17,0x3B,0xB1,
0x89,0xEC,0xA0,0x9F,0xD3,0xFC,0xC2,0x04,0x68,0x03,0xF3,0x25,0xBE,0x24,0xF1,0xBD,
0xB8,0x41,0xC9,0x27,0x0E,0xA3,0xD8,0x7F,0x5B,0x8F,0x16,0x49,0xAA,0xB2,0x18,0xA7,
0x33,0xE4,0xDB,0x48,0xCA,0xDE,0xAE,0xCD,0x13,0x1F,0x15,0x2E,0x39,0xF5,0x1E,0xDD,
0x0F,0x88,0x4C,0x98,0x36,0xB4,0x3F,0x09,0x83,0xFD,0x32,0xBA,0x14,0x30,0x7A,0x63,
0xB9,0x56,0x95,0x61,0xCC,0x8B,0xEF,0xDA,0xE5,0x2C,0xDC,0x12,0x1A,0x67,0x23,0x50,
0xD1,0xC3,0x7E,0x6D,0xB6,0x90,0x3C,0xB3,0x0B,0xE2,0x91,0x70,0xA8,0xDF,0x44,0xC4,
0xF4,0x01,0x5C,0x10,0x06,0xE7,0x54,0x40,0x43,0x72,0x38,0xBC,0xE3,0x07,0xFA,0x34,
0x02,0xA4,0xF7,0x74,0xA9,0x4D,0x42,0xA5,0x85,0x35,0x79,0xD2,0x76,0x97,0x45,0x4F,
0x08,0x5A,0xB0,0xEE,0x51,0x73,0x69,0x9E,0x94,0x47,0x77,0x29,0xD9,0x64,0x11,0xEB,
0x37,0xAC,0x20,0x62,0x9A,0x6B,0x9C,0x75,0x22,0x87,0xAB,0x78,0x53,0xC8,0x5D,0xAD,
0x2A,0xF2,0xCB,0xB7,0x0D,0xED,0x86,0x55,0xFF,0x19,0x57,0xD7,0xD5,0x60,0xC6,0x3D,
0xEA,0xC1,0x6C,0xE1,0xC0,0x65,0x84,0xC5,0xE0,0x3E,0x7D,0x28,0x66,0xAF,0x1C,0x9B,
0xCF,0x81,0x4E,0x26,0x59,0x2B,0x5F,0x7B,0xE8,0x8D,0x52,0x7C,0xF8,0x82,0x0C,0xF9,
0x8C,0xE9,0xB5,0xE6,0x31,0x93,0x46,0x5E,0x1D,0x1B,0x4B,0x71,0xD6,0x92,0x3A,0xA6,
0x2D,0x00,0x9D,0xBB,0x6E,0xF0,0x99,0xCE,0x21,0x0A,0xD0,0xF6,0xFE,0xA2,0x8A,0x96,
};
static readonly byte[][] OrderTable = {
null, // NotEncrypted
// CHAOSHEAD
new byte[] { 0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00 },
// CHAOSHEADTR1
new byte[] { 0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0x1e,0x4e,0x66,0xb6 },
// CHAOSHEADTR2
new byte[] { 0x05,0x05,0x05,0x05,0x05,0x0b,0x0b,0x0b,0x0b,0x0b,0x00,0x00,0x00,0x00,0x00,0x00 },
// MURAMASATR
new byte[] { 0x3c,0xe0,0x2e,0x2f,0x20,0x2e,0x2f,0x20,0x8e,0x80,0x80,0xf2,0xf2,0xf2,0xfa,0xfc },
// MURAMASA
new byte[] { 0x35,0x70,0x2e,0x66,0x67,0x65,0x66,0x67,0x85,0x89,0x89,0x3b,0x3b,0x8b,0x81,0x85 },
// SUMAGA
new byte[] { 0x3c,0xe0,0x2e,0x2f,0x2f,0x2f,0x2f,0x20,0x8e,0x8f,0x8f,0xf2,0xf2,0xf2,0xfc,0xfc },
// DJANGO
new byte[] { 0xee,0xee,0xee,0xee,0xee,0xee,0xee,0xee,0xee,0xee,0xee,0xee,0xee,0xee,0xee,0xee,0x1e,0x4e,0x66,0xb6 },
// DJANGOTR
new byte[] { 0xed,0xee,0xee,0xef,0xed,0xee,0xee,0xee,0xfe,0xde,0xee,0xef,0xed,0xee,0xfe,0xdf,0x1e,0x4e,0x66,0xb6 },
// LAMENTO
new byte[] { 0xee,0xee,0xee,0xee,0xee,0xee,0xee,0xee,0xee,0xee,0xee,0xee,0xee,0xee,0xee,0xee,0x1e,0x4e,0x66,0xb6 },
// SWEETPOOL
new byte[] { 0x38,0x9c,0x2a,0x8b,0x8b,0x8b,0x8b,0x8c,0x8a,0x8b,0x8b,0xae,0xae,0xae,0xa8,0xa8 },
// SUMAGASP
new byte[] { 0xab,0x6f,0x9d,0x9e,0x9f,0x9d,0x9e,0xaf,0x8d,0xff,0xff,0x71,0x71,0x71,0x79,0x7b },
// DEMONBANE
new byte[] { 0x96,0xb9,0x47,0x48,0x99,0x97,0x9c,0xaa,0x88,0xca,0xea,0x73,0x73,0x7b,0xc9,0xc6 },
// MURAMASAAD
new byte[] { 0x00,0x04,0x04,0x68,0x68,0x68,0x68,0x68,0x6f,0x6f,0x9f,0x96,0x96,0x96,0x96,0x9b },
// AXANAEL
new byte[] { 0x08,0x0c,0x0c,0xc0,0xf0,0xf0,0xf0,0xf0,0xf7,0xf7,0xf7,0xfe,0xfe,0xfe,0xfe,0xf3 },
// KIKOKUGAI
new byte[] { 0x0f,0x07,0x07,0x90,0xf7,0xf7,0xf7,0xf7,0xf2,0x47,0x47,0x49,0xc9,0xc9,0xc9,0xc3 },
// SONICOMITR2
new byte[] { 0x08,0x0a,0x0a,0x40,0xfa,0xfa,0x50,0x50,0x55,0xf7,0xf7,0xf9,0x29,0x2c,0x7c,0x73 },
// SUMAGA3P
new byte[] { 0x0f,0xef,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff },
// SONICOMI
new byte[] { 0x0e,0x0b,0x0e,0x77,0x2e,0x2e,0x80,0x86,0xb9,0x2e,0x2e,0x29,0x89,0x82,0xad,0xaa },
// LOSTX
new byte[] { 0x38,0xba,0x4b,0x5b,0x55,0xae,0xee,0xe0,0x67,0x48,0x08,0x0a,0x6a,0x3d,0x32,0x8d },
// LOSTXTRAILER
new byte[] { 0x34,0x7a,0xbb,0xcb,0x11,0x65,0xea,0x5c,0x27,0x0f,0xcf,0xc6,0x66,0x39,0x39,0xfd },
// DRAMATICALMURDER
new byte[] { 0x05,0x0d,0x0d,0x13,0xb5,0x3d,0x8d,0x2d,0x20,0xc7,0xc7,0xcf,0x1f,0xef,0xef,0x48 },
// TOTONO
new byte[] { 0x6e,0x60,0x90,0xac,0xb3,0xe3,0x83,0xd6,0xde,0x7a,0x7a,0x7f,0xef,0xbf,0xb2,0xd6 },
// some installation npa
//new byte[] { 0xa9,0xd3,0x34,0x84,0xd6,0xea,0xaa,0xdc,0xa0,0x64,0x24,0x26,0xd6,0xae,0xae,0x76 },
// PHENOMENO
new byte[] { 0x30,0x96,0xdb,0x2b,0x3d,0x81,0x02,0x74,0x47,0x2b,0xeb,0xee,0x6e,0x35,0x35,0x5d },
// NEKODA
new byte[] { 0xdc,0xdc,0xec,0xcd,0xdb,0xdc,0xdc,0xdc,0xdc,0xdc,0xdc,0xdc,0xdc,0xdc,0xdc,0xdc,0x1e,0x4e,0x66,0xb6 },
};
}
/// <summary>
/// Archive creation helper.
/// </summary>
internal class Indexer
{
List<NpaEntry> m_entries;
Encoding m_encoding = Encodings.cp932.WithFatalFallback();
int m_key;
int m_size = 0;
int m_directory_count = 0;
int m_file_count = 0;
public IEnumerable<NpaEntry> Entries { get { return m_entries; } }
public int Key { get { return m_key; } }
public int Size { get { return m_size; } }
public int TotalCount { get { return m_entries.Count; } }
public int FolderCount { get { return m_directory_count; } }
public int FileCount { get { return m_file_count; } }
public Indexer (IEnumerable<Entry> source_list, NpaOptions options)
{
m_entries = new List<NpaEntry> (source_list.Count());
m_key = NpaOpener.GetArchiveKey (options.TitleId, options.Key1, options.Key2);
foreach (var entry in source_list)
{
string name = entry.Name;
try
{
var dir = Path.GetDirectoryName (name);
int folder_id = 0;
if (!string.IsNullOrEmpty (dir))
folder_id = AddDirectory (dir);
bool compress = options.CompressContents;
if (compress) // don't compress images
compress = !FormatCatalog.Instance.LookupFileName (name).OfType<ImageFormat>().Any();
var npa_entry = new NpaEntry
{
Name = name,
IsPacked = compress,
RawName = m_encoding.GetBytes (name),
FolderId = folder_id,
};
++m_file_count;
AddEntry (npa_entry);
}
catch (EncoderFallbackException X)
{
throw new InvalidFileName (name, arcStrings.MsgIllegalCharacters, X);
}
}
}
void AddEntry (NpaEntry entry)
{
m_entries.Add (entry);
m_size += 4 + entry.RawName.Length + 17;
}
Dictionary<string, int> m_directory_map = new Dictionary<string, int>();
int AddDirectory (string dir)
{
int folder_id = 0;
if (m_directory_map.TryGetValue (dir, out folder_id))
return folder_id;
string path = "";
foreach (var component in dir.Split (Path.DirectorySeparatorChar))
{
path = Path.Combine (path, component);
if (m_directory_map.TryGetValue (path, out folder_id))
continue;
folder_id = ++m_directory_count;
m_directory_map[path] = folder_id;
var npa_entry = new NpaEntry
{
Name = path,
Type = "directory",
Offset = 0,
Size = 0,
UnpackedSize = 0,
IsPacked = false,
RawName = m_encoding.GetBytes (path),
FolderId = folder_id,
};
AddEntry (npa_entry);
}
return folder_id;
}
}
/// <summary>
/// Stream class for files stored in encrypted NPA archives.
/// </summary>
internal class EncryptedStream : Stream
{
private Stream m_stream;
private Lazy<byte[]> m_encrypted;
private int m_encrypted_length;
private bool m_read_mode;
private long m_base_pos;
public override bool CanRead { get { return m_read_mode && m_stream.CanRead; } }
public override bool CanSeek { get { return m_stream.CanSeek; } }
public override bool CanWrite { get { return !m_read_mode && m_stream.CanWrite; } }
public override long Length { get { return m_stream.Length - m_base_pos; } }
public override long Position
{
get { return m_stream.Position - m_base_pos; }
set { m_stream.Position = m_base_pos + value; }
}
delegate byte CryptFunc (int index, byte value);
CryptFunc Encrypt;
public EncryptedStream (NpaArchive arc, NpaEntry entry)
{
m_read_mode = true;
m_encrypted_length = GetEncryptedLength (entry, arc.GameId);
if (m_encrypted_length > entry.Size)
m_encrypted_length = (int)entry.Size;
int key = NpaOpener.GetKeyFromEntry (entry, arc.GameId, arc.Key);
m_stream = arc.File.CreateStream (entry.Offset, entry.Size);
m_encrypted = new Lazy<byte[]> (() => InitEncrypted (key, arc.GameId, arc.KeyTable));
m_base_pos = m_stream.Position;
}
public EncryptedStream (Stream output, NpaEntry entry, NpaTitleId game_id, int arc_key)
{
m_read_mode = false;
m_encrypted_length = GetEncryptedLength (entry, game_id);
int key = NpaOpener.GetKeyFromEntry (entry, game_id, arc_key);
m_stream = output;
m_encrypted = new Lazy<byte[]> (() => new byte[m_encrypted_length]);
m_base_pos = m_stream.Position;
byte[] decrypt_table = NpaOpener.GenerateKeyTable (game_id);
byte[] encrypt_table = new byte[256];
for (int i = 0; i < 256; ++i)
encrypt_table[decrypt_table[i]] = (byte)i;
if (NpaTitleId.LAMENTO == game_id)
{
Encrypt = (i, x) => encrypt_table[(x + key) & 0xff];
}
else
{
Encrypt = (i, x) => encrypt_table[(x + key + i) & 0xff];
}
}
int GetEncryptedLength (NpaEntry entry, NpaTitleId game_id)
{
int length = 0x1000;
if (game_id != NpaTitleId.LAMENTO)
length += entry.RawName.Length;
return length;
}
byte[] InitEncrypted (int key, NpaTitleId game_id, byte[] key_table)
{
var position = Position;
if (0 != position)
Position = 0;
byte[] buffer = new byte[m_encrypted_length];
m_encrypted_length = m_stream.Read (buffer, 0, m_encrypted_length);
Position = position;
if (game_id == NpaTitleId.LAMENTO)
{
for (int i = 0; i < m_encrypted_length; i++)
buffer[i] = (byte)(key_table[buffer[i]] - key);
}
else
{
for (int i = 0; i < m_encrypted_length; i++)
buffer[i] = (byte)(key_table[buffer[i]] - key - i);
}
return buffer;
}
#region System.IO.Stream methods
public override void Flush()
{
m_stream.Flush();
}
public override long Seek (long offset, SeekOrigin origin)
{
if (SeekOrigin.Begin == origin)
offset += m_base_pos;
offset = m_stream.Seek (offset, origin);
return offset - m_base_pos;
}
public override void SetLength (long length)
{
throw new NotSupportedException ("EncryptedStream.SetLength is not supported");
}
public override int Read (byte[] buffer, int offset, int count)
{
var position = Position;
if (position >= m_encrypted_length)
return m_stream.Read (buffer, offset, count);
int read = Math.Min (m_encrypted_length - (int)position, count);
Buffer.BlockCopy (m_encrypted.Value, (int)position, buffer, offset, read);
m_stream.Seek (read, SeekOrigin.Current);
if (read < count)
{
read += m_stream.Read (buffer, offset+read, count-read);
}
return read;
}
public override int ReadByte ()
{
var position = Position;
if (position >= m_encrypted_length)
return m_stream.ReadByte();
m_stream.Seek (1, SeekOrigin.Current);
return m_encrypted.Value[(int)position];
}
public override void Write (byte[] buffer, int offset, int count)
{
var position = Position;
if (position < m_encrypted_length)
{
int limit = (int)position + Math.Min (m_encrypted_length - (int)position, count);
for (int i = (int)position; i < limit; ++i, ++offset, --count)
{
m_encrypted.Value[i] = Encrypt (i, buffer[offset]);
}
m_stream.Write (m_encrypted.Value, (int)position, limit-(int)position);
}
if (count > 0)
m_stream.Write (buffer, offset, count);
}
public override void WriteByte (byte value)
{
var position = Position;
if (position < m_encrypted_length)
value = Encrypt ((int)position, value);
m_stream.WriteByte (value);
}
#endregion
#region IDisposable Members
bool disposed = false;
protected override void Dispose (bool disposing)
{
if (!disposed)
{
if (disposing && m_read_mode)
{
m_stream.Dispose();
}
m_encrypted = null;
disposed = true;
base.Dispose (disposing);
}
}
#endregion
}
}