NotTransform and XorTransform implementations moved to separate file.

ArcFormats/SimpleEncryption.cs

@@ -0,0 +1,100 @@
+//! \file       SimpleEncryption.cs
+//! \date       Mon Feb 29 08:19:07 2016
+//! \brief      Primitive encryption methods implementations.
+//
+// Copyright (C) 2016 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.IO;
+using System.Security.Cryptography;
+
+namespace GameRes.Formats
+{
+    public sealed class NotTransform : ICryptoTransform
+    {
+        private const int BlockSize = 256;
+
+        public bool          CanReuseTransform { get { return true; } }
+        public bool CanTransformMultipleBlocks { get { return true; } }
+        public int              InputBlockSize { get { return BlockSize; } }
+        public int             OutputBlockSize { get { return BlockSize; } }
+
+        public int TransformBlock (byte[] inputBuffer, int inputOffset, int inputCount,
+                                   byte[] outputBuffer, int outputOffset)
+        {
+            for (int i = 0; i < inputCount; ++i)
+            {
+                outputBuffer[outputOffset++] = (byte)~inputBuffer[inputOffset+i];
+            }
+            return inputCount;
+        }
+
+        public byte[] TransformFinalBlock (byte[] inputBuffer, int inputOffset, int inputCount)
+        {
+            byte[] outputBuffer = new byte[inputCount];
+            TransformBlock (inputBuffer, inputOffset, inputCount, outputBuffer, 0);
+            return outputBuffer;
+        }
+
+        public void Dispose ()
+        {
+            System.GC.SuppressFinalize (this);
+        }
+    }
+
+    public sealed class XorTransform : ICryptoTransform
+    {
+        private const int BlockSize = 256;
+        private byte m_key;
+
+        public bool          CanReuseTransform { get { return true; } }
+        public bool CanTransformMultipleBlocks { get { return true; } }
+        public int              InputBlockSize { get { return BlockSize; } }
+        public int             OutputBlockSize { get { return BlockSize; } }
+
+        public XorTransform (byte key)
+        {
+            m_key = key;
+        }
+
+        public int TransformBlock (byte[] inputBuffer, int inputOffset, int inputCount,
+                                   byte[] outputBuffer, int outputOffset)
+        {
+            for (int i = 0; i < inputCount; ++i)
+            {
+                outputBuffer[outputOffset++] = (byte)(m_key ^ inputBuffer[inputOffset+i]);
+            }
+            return inputCount;
+        }
+
+        public byte[] TransformFinalBlock (byte[] inputBuffer, int inputOffset, int inputCount)
+        {
+            byte[] outputBuffer = new byte[inputCount];
+            TransformBlock (inputBuffer, inputOffset, inputCount, outputBuffer, 0);
+            return outputBuffer;
+        }
+
+        public void Dispose ()
+        {
+            System.GC.SuppressFinalize (this);
+        }
+    }
+}