Initial Commit

iTechSharp/srcbc/crypto/engines/NullEngine.cs

@@ -0,0 +1,70 @@
+using System;
+
+using Org.BouncyCastle.Crypto.Parameters;
+
+namespace Org.BouncyCastle.Crypto.Engines
+{
+	/**
+	* The no-op engine that just copies bytes through, irrespective of whether encrypting and decrypting.
+	* Provided for the sake of completeness.
+	*/
+	public class NullEngine
+		: IBlockCipher
+	{
+		private bool initialised;
+		private const int BlockSize = 1;
+
+		public NullEngine()
+		{
+		}
+
+		public void Init(
+			bool				forEncryption,
+			ICipherParameters	parameters)
+		{
+			// we don't mind any parameters that may come in
+			initialised = true;
+		}
+
+		public string AlgorithmName
+		{
+			get { return "Null"; }
+		}
+
+		public bool IsPartialBlockOkay
+		{
+			get { return true; }
+		}
+
+		public int GetBlockSize()
+		{
+			return BlockSize;
+		}
+
+		public int ProcessBlock(
+			byte[]	input,
+			int		inOff,
+			byte[]	output,
+			int		outOff)
+		{
+			if (!initialised)
+				throw new InvalidOperationException("Null engine not initialised");
+			if ((inOff + BlockSize) > input.Length)
+				throw new DataLengthException("input buffer too short");
+			if ((outOff + BlockSize) > output.Length)
+				throw new DataLengthException("output buffer too short");
+
+			for (int i = 0; i < BlockSize; ++i)
+			{
+				output[outOff + i] = input[inOff + i];
+			}
+
+			return BlockSize;
+		}
+
+		public void Reset()
+		{
+			// nothing needs to be done
+		}
+	}
+}