implemented 'RepiPack' archives.

ArcFormats/ArcFormats.csproj

@@ -117,6 +117,7 @@
     <Compile Include="KiriKiri\CzCrypt.cs" />
     <Compile Include="Kurumi\ImageGRA.cs" />
     <Compile Include="Leaf\ArcPX.cs" />
+    <Compile Include="Littlewitch\ArcDAT.cs" />
     <Compile Include="LunaSoft\ArcPAC.cs" />
     <Compile Include="Malie\ArcLIBU.cs" />
     <Compile Include="Malie\LibScheme.cs" />

ArcFormats/Littlewitch/ArcDAT.cs

@@ -0,0 +1,254 @@
+//! \file       ArcDAT.cs
+//! \date       2017 Oct 27
+//! \brief      RepiPack resource archive.
+//
+// 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.Linq;
+using System.Text;
+using GameRes.Compression;
+using GameRes.Cryptography;
+using GameRes.Utility;
+
+namespace GameRes.Formats.Littlewitch
+{
+    [Serializable]
+    public class RepiScheme : ResourceScheme
+    {
+        public IDictionary<string, uint[]>  KnownSchemes;
+    }
+
+    internal class RepiEntry : PackedEntry
+    {
+        public bool HasEncryptionKey;
+
+        public byte[] CreateKey ()
+        {
+            var name_bytes = Encodings.cp932.GetBytes (Name.ToLowerInvariant());
+            int name_length = name_bytes.Length;
+            var md5 = new MD5();
+            Array.Reverse (name_bytes);
+            var key = new byte[1024];
+            int key_pos = 0;
+            md5.Initialize();
+            for (int i = 0; i < 64; ++i)
+            {
+                int name_pos = i % name_length;
+                md5.Update (name_bytes, name_pos, name_length - name_pos);
+                md5.Final();
+                Buffer.BlockCopy (md5.State, 0, key, key_pos, 16);
+                key_pos += 16;
+            }
+            return key;
+        }
+    }
+
+    [Export(typeof(ArchiveFormat))]
+    public class DatOpener : ArchiveFormat
+    {
+        public override string         Tag { get { return "DAT/RepiPack"; } }
+        public override string Description { get { return "Littlewitch engine resource archive"; } }
+        public override uint     Signature { get { return 0x69706552; } } // 'Repi'
+        public override bool  IsHierarchic { get { return false; } }
+        public override bool      CanWrite { get { return false; } }
+
+        static readonly string ListFileName = "littlewitch.lst";
+
+        public override ArcFile TryOpen (ArcView file)
+        {
+            if (!file.View.AsciiEqual (4, "Pack"))
+                return null;
+            int version = file.View.ReadInt32 (8);
+            if (version != 5)
+                return null;
+            uint name_length = file.View.ReadUInt32 (0xC);
+            if (name_length < 4)
+                return null;
+            uint name_key = file.View.ReadUInt32 (0x10);
+            var key = FindKey (file.Name, name_key);
+            if (null == key)
+                return null;
+            int count = file.View.ReadInt32 (0x10 + name_length);
+            if (!IsSaneCount (count))
+                return null;
+            var index = file.View.ReadBytes (0x14 + name_length, (uint)count * 0x20);
+            int pos = 0;
+            var dir = new List<Entry> (count);
+            var name_builder = new StringBuilder();
+            for (int i = 0; i < count; ++i)
+            {
+                DecryptData (index, pos, 0x20, key[2], key[1]);
+                var entry = EntryFromMd5 (index, pos, name_builder);
+                entry.Offset        = index.ToUInt32 (pos+0x10);
+                entry.Size          = index.ToUInt32 (pos+0x14);
+                entry.UnpackedSize  = index.ToUInt32 (pos+0x18);
+                if (!entry.CheckPlacement (file.MaxOffset))
+                    return null;
+                entry.IsPacked = entry.Size != entry.UnpackedSize;
+                dir.Add (entry);
+                pos += 0x20;
+            }
+            return new ArcFile (file, this, dir);
+        }
+
+        public override Stream OpenEntry (ArcFile arc, Entry entry)
+        {
+            var rent = entry as RepiEntry;
+            if (null == rent || !rent.HasEncryptionKey)
+                return arc.File.CreateStream (entry.Offset, entry.Size);
+            var key = rent.CreateKey();
+            uint enc_length = Math.Min ((uint)key.Length, entry.Size);
+            byte[] encrypted = arc.File.View.ReadBytes (entry.Offset, enc_length);
+            DecryptEntry (encrypted, key);
+            Stream input;
+            if (enc_length == entry.Size)
+            {
+                input = new BinMemoryStream (encrypted, entry.Name);
+            }
+            else
+            {
+                input = arc.File.CreateStream (entry.Offset + enc_length, entry.Size - enc_length);
+                input = new PrefixStream (encrypted, input);
+            }
+            if (rent.IsPacked)
+            {
+                input = new LzssStream (input);
+            }
+            return input;
+        }
+
+        static void DecryptEntry (byte[] data, byte[] key)
+        {
+            for (int i = 0; i < data.Length; ++i)
+            {
+                data[i] ^= key[i];
+            }
+        }
+
+        static unsafe void DecryptData (byte[] data, int pos, int length, uint key, uint seed)
+        {
+            if (pos < 0 || pos + length > data.Length)
+                throw new ArgumentOutOfRangeException ("pos", "Invalid byte array index.");
+            fixed (byte* data8 = &data[pos])
+            {
+                uint* data32 = (uint*)data8;
+                for (int count = length / 4; count > 0; --count)
+                {
+                    *data32 ^= key;
+                    key += Binary.RotL (*data32, 16) ^ seed;
+                    data32++;
+                }
+            }
+        }
+
+        RepiEntry EntryFromMd5 (byte[] data, int pos, StringBuilder builder)
+        {
+            var key = new CowArray<byte> (data, pos, 16).ToArray();
+            string name;
+            if (KnownNames.TryGetValue (key, out name))
+            {
+                var entry = FormatCatalog.Instance.Create<RepiEntry> (name);
+                entry.HasEncryptionKey = true;
+                return entry;
+            }
+            builder.Clear();
+            for (int i = 0; i < 16; ++i)
+            {
+                builder.AppendFormat ("{0:x2}", key[i]);
+            }
+            return new RepiEntry { Name = builder.ToString() };
+        }
+
+        static uint[] FindKey (string arc_name, uint arc_key)
+        {
+            arc_name = Path.GetFileName (arc_name);
+            var name_bytes = Encodings.cp932.GetBytes (arc_name);
+            arc_key ^= name_bytes.ToUInt32 (0);
+            return DatScheme.KnownSchemes.Values.FirstOrDefault (k => k[0] == arc_key);
+        }
+
+        static RepiScheme DatScheme = new RepiScheme { KnownSchemes = new Dictionary<string, uint[]>() };
+
+        public override ResourceScheme Scheme
+        {
+            get { return DatScheme; }
+            set { DatScheme = (RepiScheme)value; }
+        }
+
+        internal Dictionary<byte[], string> KnownNames { get { return s_known_file_names.Value; } }
+
+        static Lazy<Dictionary<byte[], string>> s_known_file_names = new Lazy<Dictionary<byte[], string>> (ReadFileList);
+
+        static Dictionary<byte[], string> ReadFileList ()
+        {
+            var dict = new Dictionary<byte[], string> (new Md5Comparer());
+            try
+            {
+                var md5 = new MD5();
+                FormatCatalog.Instance.ReadFileList (ListFileName, name => {
+                    var name_bytes = Encodings.cp932.GetBytes (name.ToLowerInvariant());
+                    var hash = md5.ComputeHash (name_bytes);
+                    dict[hash] = name;
+                });
+            }
+            catch (Exception X)
+            {
+                System.Diagnostics.Trace.WriteLine (X.Message, "[RepiPack]");
+            }
+            return dict;
+        }
+    }
+
+    internal class Md5Comparer : IEqualityComparer<byte[]>
+    {
+        public bool Equals (byte[] left, byte[] right)
+        {
+            if (left == null || right == null)
+                return left == right;
+            if (left.Length != right.Length)
+                return false;
+            for (int i = 0; i < left.Length; ++i)
+            {
+                if (left[i] != right[i])
+                    return false;
+            }
+            return true;
+        }
+
+        public int GetHashCode (byte[] key)
+        {
+            if (null == key)
+                throw new ArgumentNullException ("key");
+            if (key.Length < 16)
+                throw new ArgumentException ("Invalid key length.", "key");
+            var hash = key.ToInt32 (0);
+            hash ^= key.ToInt32 (4);
+            hash ^= key.ToInt32 (8);
+            hash ^= key.ToInt32 (12);
+            return hash;
+        }
+    }
+}