Merge commit 'a0095a0516508418fb4a058648f49f867f64592e' as 'FSI.Lib'

FSI.Lib/FSI.Lib/EasyEncryption/EncryptionReader.cs

@@ -0,0 +1,105 @@
+using System;
+using System.IO;
+using System.Security.Cryptography;
+
+namespace FSI.Lib.EasyEncryption
+{
+    /// <summary>
+    /// Class that provides streaming decryption functionality.
+    /// </summary>
+    /// <remarks>
+    /// Using this class is the preferred way to decrypt values from a file or memory.
+    /// Other decryption methods defer to this class for actual decryption.
+    /// </remarks>
+    public class EncryptionReader : BinaryReader, IDisposable
+    {
+        private SymmetricAlgorithm Algorithm;
+        private ICryptoTransform Decryptor;
+
+        internal EncryptionReader(SymmetricAlgorithm algorithm, ICryptoTransform decryptor, Stream stream) : base(stream)
+        {
+            Algorithm = algorithm;
+            Decryptor = decryptor;
+        }
+
+        /// <summary>
+        /// Reads a <c>DateTime</c> value from the encrypted stream.
+        /// </summary>
+        /// <returns>The decrypted value.</returns>
+        public DateTime ReadDateTime()
+        {
+            return new DateTime(ReadInt64());
+        }
+
+        /// <summary>
+        /// Reads a <c>byte[]</c> value from the encrypted stream.
+        /// </summary>
+        /// <returns>The decrypted values.</returns>
+        public byte[] ReadByteArray()
+        {
+            int count = ReadInt32();
+            byte[] bytes = new byte[count];
+            if (count > 0)
+                Read(bytes, 0, count);
+            return bytes;
+        }
+
+        /// <summary>
+        /// Reads a <c>string[]</c> value from the encrypted stream.
+        /// </summary>
+        /// <returns>The decrypted values.</returns>
+        public string[] ReadStringArray()
+        {
+            int count = ReadInt32();
+            string[] strings = new string[count];
+            for (int i = 0; i < count; i++)
+                strings[i] = ReadString();
+            return strings;
+        }
+
+        #region IDisposable implementation
+
+        private bool disposed = false; // To detect redundant calls
+
+        /// <summary>
+        /// Releases all resources used by the current instance of the <c>EncryptionReader</c> class.
+        /// </summary>
+        public new void Dispose()
+        {
+            Dispose(true);
+            GC.SuppressFinalize(this);
+        }
+
+        /// <summary>
+        /// Releases the unmanaged resources used by the <c>EncryptionReader</c> class and optionally
+        /// releases the managed resources.
+        /// </summary>
+        /// <param name="disposing"><c>true</c> to release both managed and unmanaged resources;
+        /// <c>false</c> to release only unmanaged resources.</param>
+        protected override void Dispose(bool disposing)
+        {
+            if (!disposed)
+            {
+                disposed = true;
+                if (disposing)
+                {
+                    // Dispose managed objects
+                    base.Dispose(true);
+                    Decryptor.Dispose();
+                    Algorithm.Dispose();
+                }
+            }
+        }
+
+        /// <summary>
+        /// Destructs this instance of <c>EncryptionReader</c>.
+        /// </summary>
+        ~EncryptionReader()
+        {
+            Dispose(false);
+        }
+
+        #endregion
+
+    }
+}