implemented decryption for PACKDAT archives.

ArcFormats/ArcInnGrey.cs

@@ -28,13 +28,18 @@ using System.IO;
 using System.Collections.Generic;
 using System.ComponentModel.Composition;
 
-namespace GameRes.Formats.InnocentGrey
+namespace GameRes.Formats.SystemEpsylon
 {
+    internal class PackDatEntry : PackedEntry
+    {
+        public uint Flags;
+    }
+
     [Export(typeof(ArchiveFormat))]
     public class PakOpener : ArchiveFormat
     {
         public override string         Tag { get { return "PACKDAT"; } }
-        public override string Description { get { return "Innocent Grey resource archive"; } }
+        public override string Description { get { return "SYSTEM-ε resource archive"; } }
         public override uint     Signature { get { return 0x4B434150; } } // "PACK"
         public override bool  IsHierarchic { get { return false; } }
         public override bool     CanCreate { get { return false; } }
@@ -59,9 +64,12 @@ namespace GameRes.Formats.InnocentGrey
             for (int i = 0; i < count; ++i)
             {
                 string name = file.View.ReadString (index_offset, 0x20);
-                var entry = FormatCatalog.Instance.CreateEntry (name);
+                var entry = new PackDatEntry { Name = name };
+                entry.Type   = FormatCatalog.Instance.GetTypeFromName (name);
                 entry.Offset = file.View.ReadUInt32 (index_offset+0x20);
+                entry.Flags  = file.View.ReadUInt32 (index_offset+0x24);
                 entry.Size   = file.View.ReadUInt32 (index_offset+0x28);
+                entry.UnpackedSize = file.View.ReadUInt32 (index_offset+0x2c);
                 if (!entry.CheckPlacement (file.MaxOffset))
                     return null;
                 dir.Add (entry);
@@ -69,5 +77,33 @@ namespace GameRes.Formats.InnocentGrey
             }
             return new ArcFile (file, this, dir);
         }
+
+        public override Stream OpenEntry (ArcFile arc, Entry entry)
+        {
+            var pentry = entry as PackDatEntry;
+            if (null == pentry || 0 == (pentry.Flags & 0x10000))
+                return arc.File.CreateStream (entry.Offset, entry.Size);
+
+            byte[] input = new byte[pentry.Size];
+            if (pentry.Size != arc.File.View.Read (entry.Offset, input, 0, pentry.Size))
+                return arc.File.CreateStream (entry.Offset, entry.Size);
+
+            unsafe
+            {
+                fixed (byte* buf_raw = input)
+                {
+                    uint* encoded = (uint*)buf_raw;
+                    uint key = pentry.Size >> 2;
+                    key = (key << (((int)key & 7) + 8)) ^ key;
+                    for (uint i = entry.Size / 4; i != 0; --i )
+                    {
+                        *encoded ^= key;
+                        int cl = (int)(*encoded++ % 24);
+                        key = (key << cl) | (key >> (32 - cl));
+                    }
+                }
+            }
+            return new MemoryStream (input);
+        }
     }
 }

ArcFormats/Properties/AssemblyInfo.cs

@@ -32,5 +32,5 @@ using System.Runtime.InteropServices;
 // You can specify all the values or you can default the Build and Revision Numbers 
 // by using the '*' as shown below:
 // [assembly: AssemblyVersion("1.0.*")]
-[assembly: AssemblyVersion ("1.0.8.82")]
+[assembly: AssemblyVersion ("1.0.8.83")]
-[assembly: AssemblyFileVersion ("1.0.8.82")]
+[assembly: AssemblyFileVersion ("1.0.8.83")]

supported.html

@@ -40,7 +40,8 @@ Makai Tenshi Djibril -Episode 4-<br/>
 Shukufuku no Campanella<br/>
 </td></tr>
 <tr><td>*.hg3</td><td><tt>HG-3</tt></td><td>No</td></tr>
-<tr class="odd"><td>*.pak<br/>*.dat</td><td><tt>PACKDAT.</tt></td><td>No</td><td>Innocent Grey</td><td>
+<tr class="odd"><td>*.pak<br/>*.dat</td><td><tt>PACKDAT.</tt></td><td>No</td><td>SYSTEM-ε</td><td>
+Aoiro Rinne<br/>
 Cartagra<br/>
 PP -Pianissimo-<br/>
 Nagomibako<br/>
@@ -94,6 +95,7 @@ Umineko<br/>
 <tr><td>*.pd</td><td><tt>PackOnly</tt><br/><tt>PackPlus</tt><br/><tt>FlyingShinePDFile</tt></td><td>Yes</td><td>Flying Shine</td><td>Cross†Channel</td></tr>
 <tr class="odd"><td>*.rpa</td><td><tt>RPA-3.0</tt></td><td>Yes</td><td>Ren'Py</td><td>Katawa Shoujo</td></tr>
 <tr><td>*.arc</td><td>-</td><td>Yes</td><td rowspan="2">Will</td><td rowspan="2">
+Cynthia ~Sincerely to You~<br/>
 Folklore Jam<br/>
 Yume Miru Kusuri<br/>
 </td></tr>