implemented RPG Maker archives (#107)

ArcFormats/ArcFormats.csproj

@@ -130,6 +130,7 @@
     <Compile Include="Qlie\DelphiDeserializer.cs" />
     <Compile Include="Qlie\Encryption.cs" />
     <Compile Include="RealLive\ArcKOE.cs" />
+    <Compile Include="RPGMaker\ArcRGSS.cs" />
     <Compile Include="rUGP\AudioRHA.cs" />
     <Compile Include="Lilim\ArcFGA.cs" />
     <Compile Include="Slg\ArcSPD.cs" />

ArcFormats/RPGMaker/ArcRGSS.cs

@@ -0,0 +1,178 @@
+//! \file       ArcRGSS3.cs
+//! \date       2017 Nov 18
+//! \brief      RPG Maker resource archive implementation.
+//
+// Copyright (C) 2017 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.Text;
+
+namespace GameRes.Formats.RPGMaker
+{
+    [Export(typeof(ArchiveFormat))]
+    public class RgssOpener : ArchiveFormat
+    {
+        public override string         Tag { get { return "RGSSAD"; } }
+        public override string Description { get { return "RPG Maker engine resource archive"; } }
+        public override uint     Signature { get { return 0x53534752; } } // 'RGSS'
+        public override bool  IsHierarchic { get { return true; } }
+        public override bool      CanWrite { get { return false; } }
+
+        public RgssOpener ()
+        {
+            Extensions = new string[] { "rgss3a", "rgss2a", "rgssad" };
+        }
+
+        public override ArcFile TryOpen (ArcView file)
+        {
+            if (!file.View.AsciiEqual (4, "AD\0"))
+                return null;
+            int version = file.View.ReadByte (7);
+            if (version != 3)
+                return null;
+            using (var index = file.CreateStream())
+            {
+                List<Entry> dir = null;
+                if (3 == version)
+                    dir = ReadIndexV3 (index);
+                else if (1 == version)
+                    dir = ReadIndexV1 (index);
+                if (null == dir || 0 == dir.Count)
+                    return null;
+                return new ArcFile (file, this, dir);
+            }
+        }
+
+        List<Entry> ReadIndexV1 (IBinaryStream file)
+        {
+            var max_offset = file.Length;
+            file.Position = 8;
+            var key_gen = new KeyGenerator (0xDEADCAFE);
+            var dir = new List<Entry>();
+            while (file.PeekByte() != -1)
+            {
+                uint name_length = file.ReadUInt32() ^ key_gen.GetNext();
+                var name_bytes = file.ReadBytes ((int)name_length);
+                var name = DecryptName (name_bytes, key_gen);
+                var entry = FormatCatalog.Instance.Create<RgssEntry> (name);
+                entry.Size   = file.ReadUInt32() ^ key_gen.GetNext();
+                entry.Offset = file.Position;
+                entry.Key    = key_gen.Current;
+                if (!entry.CheckPlacement (max_offset))
+                    return null;
+                dir.Add (entry);
+                file.Seek (entry.Size, SeekOrigin.Current);
+            }
+            return dir;
+        }
+
+        List<Entry> ReadIndexV3 (IBinaryStream file)
+        {
+            var max_offset = file.Length;
+            file.Position = 8;
+            uint key = file.ReadUInt32() * 9 + 3;
+            var dir = new List<Entry>();
+            while (file.PeekByte() != -1)
+            {
+                uint offset = file.ReadUInt32() ^ key;
+                if (0 == offset)
+                    break;
+                uint size        = file.ReadUInt32() ^ key;
+                uint entry_key   = file.ReadUInt32() ^ key;
+                uint name_length = file.ReadUInt32() ^ key;
+                var name_bytes = file.ReadBytes ((int)name_length);
+                var name = DecryptName (name_bytes, key);
+                var entry = FormatCatalog.Instance.Create<RgssEntry> (name);
+                entry.Offset = offset;
+                entry.Size   = size;
+                entry.Key    = entry_key;
+                if (!entry.CheckPlacement (max_offset))
+                    return null;
+                dir.Add (entry);
+            }
+            return dir;
+        }
+
+        public override Stream OpenEntry (ArcFile arc, Entry entry)
+        {
+            var rent = (RgssEntry)entry;
+            var data = arc.File.View.ReadBytes (rent.Offset, rent.Size);
+            var key_gen = new KeyGenerator (rent.Key);
+            uint key = key_gen.GetNext();
+            for (int i = 0; i < data.Length; )
+            {
+                data[i] ^= (byte)(key >> (i << 3));
+                ++i;
+                if (0 == (i & 3))
+                {
+                    key = key_gen.GetNext();
+                }
+            }
+            return new BinMemoryStream (data);
+        }
+
+        string DecryptName (byte[] name, KeyGenerator key_gen)
+        {
+            for (int i = 0; i < name.Length; ++i)
+            {
+                name[i] ^= (byte)key_gen.GetNext();
+            }
+            return Encoding.UTF8.GetString (name);
+        }
+
+        string DecryptName (byte[] name, uint key)
+        {
+            for (int i = 0; i < name.Length; ++i)
+            {
+                name[i] ^= (byte)(key >> (i << 3));
+            }
+            return Encoding.UTF8.GetString (name);
+        }
+    }
+
+    internal class RgssEntry : Entry
+    {
+        public uint Key;
+    }
+
+    internal class KeyGenerator
+    {
+        uint    m_seed;
+
+        public KeyGenerator (uint seed)
+        {
+            m_seed = seed;
+        }
+
+        public uint Current { get { return m_seed; } }
+
+        public uint GetNext ()
+        {
+            uint key = m_seed;
+            m_seed = m_seed * 7 + 3;
+            return key;
+        }
+    }
+}