Initial Commit

iTechSharp/srcbc/util/encoders/HexTranslator.cs

@@ -0,0 +1,108 @@
+using System;
+
+namespace Org.BouncyCastle.Utilities.Encoders
+{
+    /// <summary>
+    /// A hex translator.
+    /// </summary>
+    public class HexTranslator : ITranslator
+    {
+        private static readonly byte[]   hexTable =
+            {
+                (byte)'0', (byte)'1', (byte)'2', (byte)'3', (byte)'4', (byte)'5', (byte)'6', (byte)'7',
+                (byte)'8', (byte)'9', (byte)'a', (byte)'b', (byte)'c', (byte)'d', (byte)'e', (byte)'f'
+            };
+
+        /// <summary>
+        /// Return encoded block size.
+        /// </summary>
+        /// <returns>2</returns>
+        public int GetEncodedBlockSize()
+        {
+            return 2;
+        }
+
+        /// <summary>
+        /// Encode some data.
+        /// </summary>
+        /// <param name="input">Input data array.</param>
+        /// <param name="inOff">Start position within input data array.</param>
+        /// <param name="length">The amount of data to process.</param>
+        /// <param name="outBytes">The output data array.</param>
+        /// <param name="outOff">The offset within the output data array to start writing from.</param>
+        /// <returns>Amount of data encoded.</returns>
+        public int Encode(
+            byte[]  input,
+            int     inOff,
+            int     length,
+            byte[]  outBytes,
+            int     outOff)
+        {
+            for (int i = 0, j = 0; i < length; i++, j += 2)
+            {
+                outBytes[outOff + j] = hexTable[(input[inOff] >> 4) & 0x0f];
+                outBytes[outOff + j + 1] = hexTable[input[inOff] & 0x0f];
+
+                inOff++;
+            }
+
+            return length * 2;
+        }
+
+        /// <summary>
+        /// Returns the decoded block size.
+        /// </summary>
+        /// <returns>1</returns>
+        public int GetDecodedBlockSize()
+        {
+            return 1;
+        }
+
+        /// <summary>
+        /// Decode data from a byte array.
+        /// </summary>
+        /// <param name="input">The input data array.</param>
+        /// <param name="inOff">Start position within input data array.</param>
+        /// <param name="length">The amounty of data to process.</param>
+        /// <param name="outBytes">The output data array.</param>
+        /// <param name="outOff">The position within the output data array to start writing from.</param>
+        /// <returns>The amount of data written.</returns>
+        public int Decode(
+            byte[]  input,
+            int     inOff,
+            int     length,
+            byte[]  outBytes,
+            int     outOff)
+        {
+            int halfLength = length / 2;
+            byte left, right;
+            for (int i = 0; i < halfLength; i++)
+            {
+                left  = input[inOff + i * 2];
+                right = input[inOff + i * 2 + 1];
+
+                if (left < (byte)'a')
+                {
+                    outBytes[outOff] = (byte)((left - '0') << 4);
+                }
+                else
+                {
+                    outBytes[outOff] = (byte)((left - 'a' + 10) << 4);
+                }
+                if (right < (byte)'a')
+                {
+                    outBytes[outOff] += (byte)(right - '0');
+                }
+                else
+                {
+                    outBytes[outOff] += (byte)(right - 'a' + 10);
+                }
+
+                outOff++;
+            }
+
+            return halfLength;
+        }
+    }
+
+}