Initial Commit

iTechSharp/srcbc/crypto/paddings/ZeroBytePadding.cs

@@ -0,0 +1,68 @@
+using System;
+using Org.BouncyCastle.Crypto;
+using Org.BouncyCastle.Security;
+
+namespace Org.BouncyCastle.Crypto.Paddings
+{
+
+    /// <summary> A padder that adds Null byte padding to a block.</summary>
+    public class ZeroBytePadding : IBlockCipherPadding
+    {
+        /// <summary> Return the name of the algorithm the cipher implements.
+        ///
+        /// </summary>
+        /// <returns> the name of the algorithm the cipher implements.
+        /// </returns>
+        public string PaddingName
+        {
+            get { return "ZeroBytePadding"; }
+        }
+
+		/// <summary> Initialise the padder.
+        ///
+        /// </summary>
+        /// <param name="random">- a SecureRandom if available.
+        /// </param>
+        public void Init(SecureRandom random)
+        {
+            // nothing to do.
+        }
+
+        /// <summary> add the pad bytes to the passed in block, returning the
+        /// number of bytes added.
+        /// </summary>
+        public int AddPadding(
+			byte[]	input,
+			int		inOff)
+        {
+            int added = (input.Length - inOff);
+
+            while (inOff < input.Length)
+            {
+                input[inOff] = (byte) 0;
+                inOff++;
+            }
+
+            return added;
+        }
+
+		/// <summary> return the number of pad bytes present in the block.</summary>
+        public int PadCount(
+			byte[] input)
+        {
+            int count = input.Length;
+
+            while (count > 0)
+            {
+                if (input[count - 1] != 0)
+                {
+                    break;
+                }
+
+                count--;
+            }
+
+            return input.Length - count;
+        }
+    }
+}