From 97a6b331c51591d5462b06493f70304021c1c969 Mon Sep 17 00:00:00 2001
From: morkt <muvluv.ru@gmail.com>
Date: Fri, 3 Feb 2017 11:48:54 +0400
Subject: [PATCH] (WARC): another decryptor.

---
 ArcFormats/ArcFormats.csproj           |  1 +
 ArcFormats/ShiinaRio/ArcWARC.cs        | 16 +++++++------
 ArcFormats/ShiinaRio/WarcEncryption.cs | 31 ++++++++++++++++++++++++++
 3 files changed, 41 insertions(+), 7 deletions(-)

diff --git a/ArcFormats/ArcFormats.csproj b/ArcFormats/ArcFormats.csproj
index 40f9b9a5..3d2d73f8 100644
--- a/ArcFormats/ArcFormats.csproj
+++ b/ArcFormats/ArcFormats.csproj
@@ -93,6 +93,7 @@
     <Compile Include="ArcCG.cs" />
     <Compile Include="Artemis\ArcPFS.cs" />
     <Compile Include="AudioWMA.cs" />
+    <Compile Include="BlackRainbow\ArcDAT.cs" />
     <Compile Include="BlackRainbow\ArcDX.cs" />
     <Compile Include="C4\AudioVMD.cs" />
     <Compile Include="C4\ImageGD.cs" />
diff --git a/ArcFormats/ShiinaRio/ArcWARC.cs b/ArcFormats/ShiinaRio/ArcWARC.cs
index d308722c..3efb004a 100644
--- a/ArcFormats/ShiinaRio/ArcWARC.cs
+++ b/ArcFormats/ShiinaRio/ArcWARC.cs
@@ -158,13 +158,15 @@ namespace GameRes.Formats.ShiinaRio // 椎名里緒
             uint unpacked_size = LittleEndian.ToUInt32 (enc_data, 4);
             sig ^= (unpacked_size ^ 0x82AD82) & 0xffffff;
 
-            if (0 != (wentry.Flags & 0x80000000u) && entry.Size > 8) // encrypted entry
-                warc.Decoder.Decrypt (enc_data, 8, entry.Size-8);
-            if (warc.Decoder.ExtraCrypt != null)
-                warc.Decoder.ExtraCrypt.Decrypt (enc_data, 8, entry.Size-8, 0x202);
-            if (0 != (wentry.Flags & 0x20000000u) && entry.Size > 8)
-                warc.Decoder.Decrypt2 (enc_data, 8, entry.Size-8);
-
+            if (entry.Size > 8)
+            {
+                if (0 != (wentry.Flags & 0x80000000u)) // encrypted entry
+                    warc.Decoder.Decrypt (enc_data, 8, entry.Size-8);
+                if (warc.Decoder.ExtraCrypt != null)
+                    warc.Decoder.ExtraCrypt.Decrypt (enc_data, 8, entry.Size-8, 0x202);
+                if (0 != (wentry.Flags & 0x20000000u))
+                    warc.Decoder.Decrypt2 (enc_data, 8, entry.Size-8);
+            }
             byte[] unpacked = enc_data;
             UnpackMethod unpack = null;
             switch (sig & 0xffffff)
diff --git a/ArcFormats/ShiinaRio/WarcEncryption.cs b/ArcFormats/ShiinaRio/WarcEncryption.cs
index 69665878..b1bd0daa 100644
--- a/ArcFormats/ShiinaRio/WarcEncryption.cs
+++ b/ArcFormats/ShiinaRio/WarcEncryption.cs
@@ -1126,4 +1126,35 @@ namespace GameRes.Formats.ShiinaRio
             }
         }
     }
+
+    [Serializable]
+    public class CountCrypt : IDecryptExtra
+    {
+        public void Decrypt (byte[] data, int index, uint length, uint flags)
+        {
+            if (length >= 0x200 && (flags & 0x204) == 0x204)
+                DoCountCrypt (data, index, (int)length);
+        }
+
+        public void Encrypt (byte[] data, int index, uint length, uint flags)
+        {
+            if (length >= 0x200 && (flags & 0x104) == 0x104)
+                DoCountCrypt (data, index, (int)length);
+        }
+
+        void DoCountCrypt (byte[] data, int index, int length)
+        {
+            length = (length & 0x7E) | 1;
+            byte count_00 = 0, count_FF = 0;
+            for (int i = 0; i < length; ++i)
+            {
+                if (0xFF == data[index+i])
+                    count_FF++;
+                else if (0 == data[index+i])
+                    count_00++;
+            }
+            data[index + 0x100] ^= count_00;
+            data[index + 0x104] ^= count_FF;
+        }
+    }
 }