diff --git a/ArcFormats/ArcFormats.csproj b/ArcFormats/ArcFormats.csproj
index d0cdf557..cb02783c 100644
--- a/ArcFormats/ArcFormats.csproj
+++ b/ArcFormats/ArcFormats.csproj
@@ -132,6 +132,7 @@
+
@@ -649,6 +650,7 @@
+
diff --git a/ArcFormats/Cmvs/ArcCPZ1.cs b/ArcFormats/Cmvs/ArcCPZ1.cs
new file mode 100644
index 00000000..62bcd2bc
--- /dev/null
+++ b/ArcFormats/Cmvs/ArcCPZ1.cs
@@ -0,0 +1,101 @@
+//! \file ArcCPZ1.cs
+//! \date 2018 May 21
+//! \brief Purple Software 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.Collections.Generic;
+using System.ComponentModel.Composition;
+using System.IO;
+using GameRes.Utility;
+
+namespace GameRes.Formats.Purple
+{
+ [Export(typeof(ArchiveFormat))]
+ public class Cpz1Opener : ArchiveFormat
+ {
+ public override string Tag { get { return "CPZ1"; } }
+ public override string Description { get { return "CVNS engine resource archive"; } }
+ public override uint Signature { get { return 0x315A5043; } } // 'CPZ1'
+ public override bool IsHierarchic { get { return false; } }
+ public override bool CanWrite { get { return false; } }
+
+ public Cpz1Opener ()
+ {
+ Extensions = new string[] { "cpz" };
+ }
+
+ public override ArcFile TryOpen (ArcView file)
+ {
+ int count = file.View.ReadInt32 (4);
+ if (!IsSaneCount (count))
+ return null;
+ uint index_size = file.View.ReadUInt32 (8);
+ var index = file.View.ReadBytes (0x10, index_size);
+ DecryptData (index, DefaultKey);
+ long base_offset = 0x10 + index_size;
+ int index_offset = 0;
+ var dir = new List (count);
+ for (int i = 0; i < count; ++i)
+ {
+ int entry_size = LittleEndian.ToInt32 (index, index_offset);
+ if (entry_size <= 0 || entry_size > index.Length - index_offset)
+ return null;
+ var name = Binary.GetCString (index, index_offset+0x18);
+ var entry = FormatCatalog.Instance.Create (name);
+ entry.Size = LittleEndian.ToUInt32 (index, index_offset+4);
+ entry.Offset = LittleEndian.ToUInt32 (index, index_offset+8) + base_offset;
+ if (!entry.CheckPlacement (file.MaxOffset))
+ return null;
+ dir.Add (entry);
+ index_offset += entry_size;
+ }
+ return new ArcFile (file, this, dir);
+ }
+
+ public override Stream OpenEntry (ArcFile arc, Entry entry)
+ {
+ var data = arc.File.View.ReadBytes (entry.Offset, entry.Size);
+ DecryptData (data, DefaultKey);
+ if (Binary.AsciiEqual (data, "PSS0"))
+ data = CpzOpener.UnpackLzss (data);
+ return new BinMemoryStream (data, entry.Name);
+ }
+
+ void DecryptData (byte[] data, byte[] key)
+ {
+ if (key.Length < 0x40)
+ throw new System.ArgumentException ("Invalid CPZ1 key");
+ for (int i = 0; i < data.Length; i++)
+ {
+ data[i] = (byte)((data[i] ^ key[i & 0x3F]) - 0x6C);
+ }
+ }
+
+ static readonly byte[] DefaultKey = {
+ 0x92, 0xCD, 0x97, 0x90, 0x8C, 0xD7, 0x8C, 0xD5, 0x8B, 0x4B, 0x93, 0xFA, 0x9A, 0xD7, 0x8C, 0xBF,
+ 0x8C, 0xC9, 0x8C, 0xEB, 0x8D, 0x69, 0x8D, 0x8B, 0x8C, 0xD2, 0x8C, 0xD6, 0x8B, 0x6D, 0x8C, 0xE3,
+ 0x8C, 0xFB, 0x8C, 0xD0, 0x8C, 0xC8, 0x8C, 0xF0, 0x8B, 0xFE, 0x8C, 0xAA, 0x8C, 0xF4, 0x8B, 0x4B,
+ 0x9C, 0x58, 0x8C, 0xD3, 0x96, 0xC8, 0x8C, 0xCB, 0x8C, 0xCE, 0x8C, 0xF3, 0x8C, 0xD6, 0x8B, 0x52,
+ };
+ }
+}