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-rw-r--r--crypto/src/util/encoders/Base64.cs120
-rw-r--r--crypto/src/util/encoders/Base64Encoder.cs307
-rw-r--r--crypto/src/util/encoders/BufferedDecoder.cs117
-rw-r--r--crypto/src/util/encoders/BufferedEncoder.cs117
-rw-r--r--crypto/src/util/encoders/Hex.cs130
-rw-r--r--crypto/src/util/encoders/HexEncoder.cs163
-rw-r--r--crypto/src/util/encoders/HexTranslator.cs108
-rw-r--r--crypto/src/util/encoders/IEncoder.cs18
-rw-r--r--crypto/src/util/encoders/Translator.cs19
-rw-r--r--crypto/src/util/encoders/UrlBase64.cs127
-rw-r--r--crypto/src/util/encoders/UrlBase64Encoder.cs31
11 files changed, 1257 insertions, 0 deletions
diff --git a/crypto/src/util/encoders/Base64.cs b/crypto/src/util/encoders/Base64.cs
new file mode 100644
index 000000000..ccecd8dc2
--- /dev/null
+++ b/crypto/src/util/encoders/Base64.cs
@@ -0,0 +1,120 @@
+using System;
+using System.IO;
+using System.Text;
+
+namespace Org.BouncyCastle.Utilities.Encoders
+{
+    public sealed class Base64
+    {
+        private Base64()
+        {
+        }
+
+        public static string ToBase64String(
+            byte[] data)
+        {
+            return Convert.ToBase64String(data, 0, data.Length);
+        }
+
+        public static string ToBase64String(
+            byte[] data,
+            int off,
+            int length)
+        {
+            return Convert.ToBase64String(data, off, length);
+        }
+
+        /**
+         * encode the input data producing a base 64 encoded byte array.
+         *
+         * @return a byte array containing the base 64 encoded data.
+         */
+        public static byte[] Encode(
+            byte[] data)
+        {
+            return Encode(data, 0, data.Length);
+        }
+
+        /**
+         * encode the input data producing a base 64 encoded byte array.
+         *
+         * @return a byte array containing the base 64 encoded data.
+         */
+        public static byte[] Encode(
+            byte[] data,
+            int off,
+            int length)
+        {
+            string s = Convert.ToBase64String(data, off, length);
+            return Strings.ToAsciiByteArray(s);
+        }
+
+        /**
+         * Encode the byte data to base 64 writing it to the given output stream.
+         *
+         * @return the number of bytes produced.
+         */
+        public static int Encode(
+            byte[]	data,
+            Stream	outStream)
+        {
+            byte[] encoded = Encode(data);
+            outStream.Write(encoded, 0, encoded.Length);
+            return encoded.Length;
+        }
+
+        /**
+         * Encode the byte data to base 64 writing it to the given output stream.
+         *
+         * @return the number of bytes produced.
+         */
+        public static int Encode(
+            byte[]	data,
+            int		off,
+            int		length,
+            Stream	outStream)
+        {
+            byte[] encoded = Encode(data, off, length);
+            outStream.Write(encoded, 0, encoded.Length);
+            return encoded.Length;
+        }
+
+        /**
+         * decode the base 64 encoded input data. It is assumed the input data is valid.
+         *
+         * @return a byte array representing the decoded data.
+         */
+        public static byte[] Decode(
+            byte[] data)
+        {
+            string s = Strings.FromAsciiByteArray(data);
+            return Convert.FromBase64String(s);
+        }
+
+        /**
+         * decode the base 64 encoded string data - whitespace will be ignored.
+         *
+         * @return a byte array representing the decoded data.
+         */
+        public static byte[] Decode(
+            string data)
+        {
+            return Convert.FromBase64String(data);
+        }
+
+        /**
+         * decode the base 64 encoded string data writing it to the given output stream,
+         * whitespace characters will be ignored.
+         *
+         * @return the number of bytes produced.
+         */
+        public static int Decode(
+            string	data,
+            Stream	outStream)
+        {
+            byte[] decoded = Decode(data);
+            outStream.Write(decoded, 0, decoded.Length);
+            return decoded.Length;
+        }
+    }
+}
diff --git a/crypto/src/util/encoders/Base64Encoder.cs b/crypto/src/util/encoders/Base64Encoder.cs
new file mode 100644
index 000000000..c94ce9d3c
--- /dev/null
+++ b/crypto/src/util/encoders/Base64Encoder.cs
@@ -0,0 +1,307 @@
+using System;
+using System.IO;
+
+namespace Org.BouncyCastle.Utilities.Encoders
+{
+	public class Base64Encoder
+		: IEncoder
+	{
+		protected readonly byte[] encodingTable =
+		{
+			(byte)'A', (byte)'B', (byte)'C', (byte)'D', (byte)'E', (byte)'F', (byte)'G',
+			(byte)'H', (byte)'I', (byte)'J', (byte)'K', (byte)'L', (byte)'M', (byte)'N',
+			(byte)'O', (byte)'P', (byte)'Q', (byte)'R', (byte)'S', (byte)'T', (byte)'U',
+			(byte)'V', (byte)'W', (byte)'X', (byte)'Y', (byte)'Z',
+			(byte)'a', (byte)'b', (byte)'c', (byte)'d', (byte)'e', (byte)'f', (byte)'g',
+			(byte)'h', (byte)'i', (byte)'j', (byte)'k', (byte)'l', (byte)'m', (byte)'n',
+			(byte)'o', (byte)'p', (byte)'q', (byte)'r', (byte)'s', (byte)'t', (byte)'u',
+			(byte)'v',
+			(byte)'w', (byte)'x', (byte)'y', (byte)'z',
+			(byte)'0', (byte)'1', (byte)'2', (byte)'3', (byte)'4', (byte)'5', (byte)'6',
+			(byte)'7', (byte)'8', (byte)'9',
+			(byte)'+', (byte)'/'
+		};
+
+		protected byte padding = (byte)'=';
+
+		/*
+		* set up the decoding table.
+		*/
+		protected readonly byte[] decodingTable = new byte[128];
+
+		protected void InitialiseDecodingTable()
+		{
+			for (int i = 0; i < encodingTable.Length; i++)
+			{
+				decodingTable[encodingTable[i]] = (byte)i;
+			}
+		}
+
+		public Base64Encoder()
+		{
+			InitialiseDecodingTable();
+		}
+
+		/**
+		* encode the input data producing a base 64 output stream.
+		*
+		* @return the number of bytes produced.
+		*/
+		public int Encode(
+			byte[]	data,
+			int		off,
+			int		length,
+			Stream	outStream)
+		{
+			int modulus = length % 3;
+			int dataLength = (length - modulus);
+			int a1, a2, a3;
+
+			for (int i = off; i < off + dataLength; i += 3)
+			{
+				a1 = data[i] & 0xff;
+				a2 = data[i + 1] & 0xff;
+				a3 = data[i + 2] & 0xff;
+
+				outStream.WriteByte(encodingTable[(int) ((uint) a1 >> 2) & 0x3f]);
+				outStream.WriteByte(encodingTable[((a1 << 4) | (int) ((uint) a2 >> 4)) & 0x3f]);
+				outStream.WriteByte(encodingTable[((a2 << 2) | (int) ((uint) a3 >> 6)) & 0x3f]);
+				outStream.WriteByte(encodingTable[a3 & 0x3f]);
+			}
+
+			/*
+			* process the tail end.
+			*/
+			int b1, b2, b3;
+			int d1, d2;
+
+			switch (modulus)
+			{
+				case 0:        /* nothing left to do */
+					break;
+				case 1:
+					d1 = data[off + dataLength] & 0xff;
+					b1 = (d1 >> 2) & 0x3f;
+					b2 = (d1 << 4) & 0x3f;
+
+					outStream.WriteByte(encodingTable[b1]);
+					outStream.WriteByte(encodingTable[b2]);
+					outStream.WriteByte(padding);
+					outStream.WriteByte(padding);
+					break;
+				case 2:
+					d1 = data[off + dataLength] & 0xff;
+					d2 = data[off + dataLength + 1] & 0xff;
+
+					b1 = (d1 >> 2) & 0x3f;
+					b2 = ((d1 << 4) | (d2 >> 4)) & 0x3f;
+					b3 = (d2 << 2) & 0x3f;
+
+					outStream.WriteByte(encodingTable[b1]);
+					outStream.WriteByte(encodingTable[b2]);
+					outStream.WriteByte(encodingTable[b3]);
+					outStream.WriteByte(padding);
+					break;
+			}
+
+			return (dataLength / 3) * 4 + ((modulus == 0) ? 0 : 4);
+		}
+
+		private bool ignore(
+			char c)
+		{
+			return (c == '\n' || c =='\r' || c == '\t' || c == ' ');
+		}
+
+		/**
+		* decode the base 64 encoded byte data writing it to the given output stream,
+		* whitespace characters will be ignored.
+		*
+		* @return the number of bytes produced.
+		*/
+		public int Decode(
+			byte[]	data,
+			int		off,
+			int		length,
+			Stream	outStream)
+		{
+			byte b1, b2, b3, b4;
+			int outLen = 0;
+
+			int end = off + length;
+
+			while (end > off)
+			{
+				if (!ignore((char)data[end - 1]))
+				{
+					break;
+				}
+
+				end--;
+			}
+
+			int  i = off;
+			int  finish = end - 4;
+
+			i = nextI(data, i, finish);
+
+			while (i < finish)
+			{
+				b1 = decodingTable[data[i++]];
+
+				i = nextI(data, i, finish);
+
+				b2 = decodingTable[data[i++]];
+
+				i = nextI(data, i, finish);
+
+				b3 = decodingTable[data[i++]];
+
+				i = nextI(data, i, finish);
+
+				b4 = decodingTable[data[i++]];
+
+				outStream.WriteByte((byte)((b1 << 2) | (b2 >> 4)));
+				outStream.WriteByte((byte)((b2 << 4) | (b3 >> 2)));
+				outStream.WriteByte((byte)((b3 << 6) | b4));
+
+				outLen += 3;
+
+				i = nextI(data, i, finish);
+			}
+
+			outLen += decodeLastBlock(outStream, (char)data[end - 4], (char)data[end - 3], (char)data[end - 2], (char)data[end - 1]);
+
+			return outLen;
+		}
+
+		private int nextI(
+			byte[]	data,
+			int		i,
+			int		finish)
+		{
+			while ((i < finish) && ignore((char)data[i]))
+			{
+				i++;
+			}
+			return i;
+		}
+
+		/**
+		* decode the base 64 encoded string data writing it to the given output stream,
+		* whitespace characters will be ignored.
+		*
+		* @return the number of bytes produced.
+		*/
+		public int DecodeString(
+			string	data,
+			Stream	outStream)
+		{
+			// Platform Implementation
+//			byte[] bytes = Convert.FromBase64String(data);
+//			outStream.Write(bytes, 0, bytes.Length);
+//			return bytes.Length;
+
+			byte b1, b2, b3, b4;
+			int length = 0;
+
+			int end = data.Length;
+
+			while (end > 0)
+			{
+				if (!ignore(data[end - 1]))
+				{
+					break;
+				}
+
+				end--;
+			}
+
+			int  i = 0;
+			int  finish = end - 4;
+
+			i = nextI(data, i, finish);
+
+			while (i < finish)
+			{
+				b1 = decodingTable[data[i++]];
+
+				i = nextI(data, i, finish);
+
+				b2 = decodingTable[data[i++]];
+
+				i = nextI(data, i, finish);
+
+				b3 = decodingTable[data[i++]];
+
+				i = nextI(data, i, finish);
+
+				b4 = decodingTable[data[i++]];
+
+				outStream.WriteByte((byte)((b1 << 2) | (b2 >> 4)));
+				outStream.WriteByte((byte)((b2 << 4) | (b3 >> 2)));
+				outStream.WriteByte((byte)((b3 << 6) | b4));
+
+				length += 3;
+
+				i = nextI(data, i, finish);
+			}
+
+			length += decodeLastBlock(outStream, data[end - 4], data[end - 3], data[end - 2], data[end - 1]);
+
+			return length;
+		}
+
+		private int decodeLastBlock(
+			Stream	outStream,
+			char	c1,
+			char	c2,
+			char	c3,
+			char	c4)
+		{
+			if (c3 == padding)
+			{
+				byte b1 = decodingTable[c1];
+				byte b2 = decodingTable[c2];
+
+				outStream.WriteByte((byte)((b1 << 2) | (b2 >> 4)));
+
+				return 1;
+			}
+
+			if (c4 == padding)
+			{
+				byte b1 = decodingTable[c1];
+				byte b2 = decodingTable[c2];
+				byte b3 = decodingTable[c3];
+
+				outStream.WriteByte((byte)((b1 << 2) | (b2 >> 4)));
+				outStream.WriteByte((byte)((b2 << 4) | (b3 >> 2)));
+
+				return 2;
+			}
+
+			{
+				byte b1 = decodingTable[c1];
+				byte b2 = decodingTable[c2];
+				byte b3 = decodingTable[c3];
+				byte b4 = decodingTable[c4];
+
+				outStream.WriteByte((byte)((b1 << 2) | (b2 >> 4)));
+				outStream.WriteByte((byte)((b2 << 4) | (b3 >> 2)));
+				outStream.WriteByte((byte)((b3 << 6) | b4));
+
+				return 3;
+			}
+		}
+
+		private int nextI(string data, int i, int finish)
+		{
+			while ((i < finish) && ignore(data[i]))
+			{
+				i++;
+			}
+			return i;
+		}
+	}
+}
diff --git a/crypto/src/util/encoders/BufferedDecoder.cs b/crypto/src/util/encoders/BufferedDecoder.cs
new file mode 100644
index 000000000..633cf1e97
--- /dev/null
+++ b/crypto/src/util/encoders/BufferedDecoder.cs
@@ -0,0 +1,117 @@
+using System;
+
+namespace Org.BouncyCastle.Utilities.Encoders
+{
+    /// <summary>
+    ///  A buffering class to allow translation from one format to another to
+    ///     be done in discrete chunks.
+    /// </summary>
+    public class BufferedDecoder
+    {
+        internal byte[]        buffer;
+        internal int           bufOff;
+
+        internal ITranslator   translator;
+
+        /// <summary>
+        /// Create a buffered Decoder.
+        /// </summary>
+        /// <param name="translator">The translater to use.</param>
+        /// <param name="bufferSize">The size of the buffer.</param>
+        public BufferedDecoder(
+            ITranslator translator,
+            int         bufferSize)
+        {
+            this.translator = translator;
+
+            if ((bufferSize % translator.GetEncodedBlockSize()) != 0)
+            {
+                throw new ArgumentException("buffer size not multiple of input block size");
+            }
+
+            buffer = new byte[bufferSize];
+//            bufOff = 0;
+        }
+
+        /// <summary>
+        /// Process one byte of data.
+        /// </summary>
+        /// <param name="input">Data in.</param>
+        /// <param name="output">Byte array for the output.</param>
+        /// <param name="outOff">The offset in the output byte array to start writing from.</param>
+        /// <returns>The amount of output bytes.</returns>
+        public int ProcessByte(
+            byte        input,
+            byte[]      output,
+            int         outOff)
+        {
+            int         resultLen = 0;
+
+            buffer[bufOff++] = input;
+
+            if (bufOff == buffer.Length)
+            {
+                resultLen = translator.Decode(buffer, 0, buffer.Length, output, outOff);
+                bufOff = 0;
+            }
+
+            return resultLen;
+        }
+
+
+        /// <summary>
+        /// Process data from a byte array.
+        /// </summary>
+        /// <param name="input">The input data.</param>
+        /// <param name="inOff">Start position within input data array.</param>
+        /// <param name="len">Amount of data to process from input data array.</param>
+        /// <param name="outBytes">Array to store output.</param>
+        /// <param name="outOff">Position in output array to start writing from.</param>
+        /// <returns>The amount of output bytes.</returns>
+        public int ProcessBytes(
+            byte[]      input,
+            int         inOff,
+            int         len,
+            byte[]      outBytes,
+            int         outOff)
+        {
+            if (len < 0)
+            {
+            throw new ArgumentException("Can't have a negative input length!");
+            }
+
+            int resultLen = 0;
+            int gapLen = buffer.Length - bufOff;
+
+            if (len > gapLen)
+            {
+                Array.Copy(input, inOff, buffer, bufOff, gapLen);
+
+                resultLen += translator.Decode(buffer, 0, buffer.Length, outBytes, outOff);
+
+                bufOff = 0;
+
+                len -= gapLen;
+                inOff += gapLen;
+                outOff += resultLen;
+
+                int chunkSize = len - (len % buffer.Length);
+
+                resultLen += translator.Decode(input, inOff, chunkSize, outBytes, outOff);
+
+                len -= chunkSize;
+                inOff += chunkSize;
+            }
+
+            if (len != 0)
+            {
+                Array.Copy(input, inOff, buffer, bufOff, len);
+
+                bufOff += len;
+            }
+
+            return resultLen;
+        }
+    }
+
+}
diff --git a/crypto/src/util/encoders/BufferedEncoder.cs b/crypto/src/util/encoders/BufferedEncoder.cs
new file mode 100644
index 000000000..5c3b1ab46
--- /dev/null
+++ b/crypto/src/util/encoders/BufferedEncoder.cs
@@ -0,0 +1,117 @@
+using System;
+
+namespace Org.BouncyCastle.Utilities.Encoders
+{
+    /// <summary>
+    /// A class that allows encoding of data using a specific encoder to be processed in chunks.
+    /// </summary>
+    public class BufferedEncoder
+    {
+        internal byte[]        Buffer;
+        internal int           bufOff;
+
+        internal ITranslator   translator;
+
+
+        /// <summary>
+        /// Create.
+        /// </summary>
+        /// <param name="translator">The translator to use.</param>
+        /// <param name="bufferSize">Size of the chunks.</param>
+        public BufferedEncoder(
+            ITranslator translator,
+            int         bufferSize)
+        {
+            this.translator = translator;
+
+            if ((bufferSize % translator.GetEncodedBlockSize()) != 0)
+            {
+                throw new ArgumentException("buffer size not multiple of input block size");
+            }
+
+            Buffer = new byte[bufferSize];
+//            bufOff = 0;
+        }
+
+
+        /// <summary>
+        /// Process one byte of data.
+        /// </summary>
+        /// <param name="input">The byte.</param>
+        /// <param name="outBytes">An array to store output in.</param>
+        /// <param name="outOff">Offset within output array to start writing from.</param>
+        /// <returns></returns>
+        public int ProcessByte(
+            byte        input,
+            byte[]      outBytes,
+            int         outOff)
+        {
+            int         resultLen = 0;
+
+            Buffer[bufOff++] = input;
+
+            if (bufOff == Buffer.Length)
+            {
+                resultLen = translator.Encode(Buffer, 0, Buffer.Length, outBytes, outOff);
+                bufOff = 0;
+            }
+
+            return resultLen;
+        }
+
+        /// <summary>
+        /// Process data from a byte array.
+        /// </summary>
+        /// <param name="input">Input data Byte array containing data to be processed.</param>
+        /// <param name="inOff">Start position within input data array.</param>
+        /// <param name="len">Amount of input data to be processed.</param>
+        /// <param name="outBytes">Output data array.</param>
+        /// <param name="outOff">Offset within output data array to start writing to.</param>
+        /// <returns>The amount of data written.</returns>
+        public int ProcessBytes(
+            byte[]      input,
+            int         inOff,
+            int         len,
+            byte[]      outBytes,
+            int         outOff)
+        {
+            if (len < 0)
+            {
+            throw new ArgumentException("Can't have a negative input length!");
+            }
+
+            int resultLen = 0;
+            int gapLen = Buffer.Length - bufOff;
+
+            if (len > gapLen)
+            {
+                Array.Copy(input, inOff, Buffer, bufOff, gapLen);
+
+                resultLen += translator.Encode(Buffer, 0, Buffer.Length, outBytes, outOff);
+
+                bufOff = 0;
+
+                len -= gapLen;
+                inOff += gapLen;
+                outOff += resultLen;
+
+                int chunkSize = len - (len % Buffer.Length);
+
+                resultLen += translator.Encode(input, inOff, chunkSize, outBytes, outOff);
+
+                len -= chunkSize;
+                inOff += chunkSize;
+            }
+
+            if (len != 0)
+            {
+                Array.Copy(input, inOff, Buffer, bufOff, len);
+
+                bufOff += len;
+            }
+
+            return resultLen;
+        }
+    }
+
+}
diff --git a/crypto/src/util/encoders/Hex.cs b/crypto/src/util/encoders/Hex.cs
new file mode 100644
index 000000000..3540a9d1e
--- /dev/null
+++ b/crypto/src/util/encoders/Hex.cs
@@ -0,0 +1,130 @@
+using System;
+using System.IO;
+using System.Text;
+
+namespace Org.BouncyCastle.Utilities.Encoders
+{
+    /// <summary>
+    /// Class to decode and encode Hex.
+    /// </summary>
+    public sealed class Hex
+    {
+        private static readonly IEncoder encoder = new HexEncoder();
+
+        private Hex()
+        {
+        }
+
+        public static string ToHexString(
+            byte[] data)
+        {
+            return ToHexString(data, 0, data.Length);
+        }
+
+        public static string ToHexString(
+            byte[]	data,
+            int		off,
+            int		length)
+        {
+            byte[] hex = Encode(data, off, length);
+            return Strings.FromAsciiByteArray(hex);
+        }
+
+        /**
+         * encode the input data producing a Hex encoded byte array.
+         *
+         * @return a byte array containing the Hex encoded data.
+         */
+        public static byte[] Encode(
+            byte[] data)
+        {
+            return Encode(data, 0, data.Length);
+        }
+
+        /**
+         * encode the input data producing a Hex encoded byte array.
+         *
+         * @return a byte array containing the Hex encoded data.
+         */
+        public static byte[] Encode(
+            byte[]	data,
+            int		off,
+            int		length)
+        {
+            MemoryStream bOut = new MemoryStream(length * 2);
+
+            encoder.Encode(data, off, length, bOut);
+
+            return bOut.ToArray();
+        }
+
+        /**
+         * Hex encode the byte data writing it to the given output stream.
+         *
+         * @return the number of bytes produced.
+         */
+        public static int Encode(
+            byte[]	data,
+            Stream	outStream)
+        {
+            return encoder.Encode(data, 0, data.Length, outStream);
+        }
+
+        /**
+         * Hex encode the byte data writing it to the given output stream.
+         *
+         * @return the number of bytes produced.
+         */
+        public static int Encode(
+            byte[]	data,
+            int		off,
+            int		length,
+            Stream	outStream)
+        {
+            return encoder.Encode(data, off, length, outStream);
+        }
+
+        /**
+         * decode the Hex encoded input data. It is assumed the input data is valid.
+         *
+         * @return a byte array representing the decoded data.
+         */
+        public static byte[] Decode(
+            byte[] data)
+        {
+            MemoryStream bOut = new MemoryStream((data.Length + 1) / 2);
+
+            encoder.Decode(data, 0, data.Length, bOut);
+
+            return bOut.ToArray();
+        }
+
+        /**
+         * decode the Hex encoded string data - whitespace will be ignored.
+         *
+         * @return a byte array representing the decoded data.
+         */
+        public static byte[] Decode(
+            string data)
+        {
+            MemoryStream bOut = new MemoryStream((data.Length + 1) / 2);
+
+            encoder.DecodeString(data, bOut);
+
+            return bOut.ToArray();
+        }
+
+        /**
+         * decode the Hex encoded string data writing it to the given output stream,
+         * whitespace characters will be ignored.
+         *
+         * @return the number of bytes produced.
+         */
+        public static int Decode(
+            string	data,
+            Stream	outStream)
+        {
+            return encoder.DecodeString(data, outStream);
+        }
+    }
+}
diff --git a/crypto/src/util/encoders/HexEncoder.cs b/crypto/src/util/encoders/HexEncoder.cs
new file mode 100644
index 000000000..e69a78b0b
--- /dev/null
+++ b/crypto/src/util/encoders/HexEncoder.cs
@@ -0,0 +1,163 @@
+using System;
+using System.IO;
+
+namespace Org.BouncyCastle.Utilities.Encoders
+{
+	public class HexEncoder
+		: IEncoder
+	{
+		private static readonly byte[] encodingTable =
+		{
+			(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'
+		};
+
+        private static readonly byte[] decodingTable = ConstructDecodingTable(encodingTable);
+
+        private static byte[] ConstructDecodingTable(byte[] et)
+		{
+            byte[] dt = new byte[128];
+			for (int i = 0; i < et.Length; i++)
+			{
+				dt[et[i]] = (byte)i;
+			}
+
+			dt['A'] = dt['a'];
+			dt['B'] = dt['b'];
+			dt['C'] = dt['c'];
+			dt['D'] = dt['d'];
+			dt['E'] = dt['e'];
+			dt['F'] = dt['f'];
+
+            return dt;
+		}
+
+        /**
+		* encode the input data producing a Hex output stream.
+		*
+		* @return the number of bytes produced.
+		*/
+		public int Encode(
+			byte[]	data,
+			int		off,
+			int		length,
+			Stream	outStream)
+		{
+			for (int i = off; i < (off + length); i++)
+			{
+				int v = data[i];
+
+				outStream.WriteByte(encodingTable[v >> 4]);
+				outStream.WriteByte(encodingTable[v & 0xf]);
+			}
+
+			return length * 2;
+		}
+
+        private static bool Ignore(char c)
+        {
+            return c == '\n' || c =='\r' || c == '\t' || c == ' ';
+        }
+
+        /**
+		* decode the Hex encoded byte data writing it to the given output stream,
+		* whitespace characters will be ignored.
+		*
+		* @return the number of bytes produced.
+		*/
+		public int Decode(
+			byte[]	data,
+			int		off,
+			int		length,
+			Stream	outStream)
+		{
+			byte b1, b2;
+			int outLen = 0;
+			int end = off + length;
+
+			while (end > off)
+			{
+				if (!Ignore((char)data[end - 1]))
+				{
+					break;
+				}
+
+				end--;
+			}
+
+			int i = off;
+			while (i < end)
+			{
+				while (i < end && Ignore((char)data[i]))
+				{
+					i++;
+				}
+
+				b1 = decodingTable[data[i++]];
+
+				while (i < end && Ignore((char)data[i]))
+				{
+					i++;
+				}
+
+				b2 = decodingTable[data[i++]];
+
+				outStream.WriteByte((byte)((b1 << 4) | b2));
+
+				outLen++;
+			}
+
+			return outLen;
+		}
+
+		/**
+		* decode the Hex encoded string data writing it to the given output stream,
+		* whitespace characters will be ignored.
+		*
+		* @return the number of bytes produced.
+		*/
+		public int DecodeString(
+			string	data,
+			Stream	outStream)
+		{
+			byte    b1, b2;
+			int     length = 0;
+
+			int     end = data.Length;
+
+			while (end > 0)
+			{
+				if (!Ignore(data[end - 1]))
+				{
+					break;
+				}
+
+				end--;
+			}
+
+			int i = 0;
+			while (i < end)
+			{
+				while (i < end && Ignore(data[i]))
+				{
+					i++;
+				}
+
+				b1 = decodingTable[data[i++]];
+
+				while (i < end && Ignore(data[i]))
+				{
+					i++;
+				}
+
+				b2 = decodingTable[data[i++]];
+
+				outStream.WriteByte((byte)((b1 << 4) | b2));
+
+				length++;
+			}
+
+			return length;
+		}
+	}
+}
diff --git a/crypto/src/util/encoders/HexTranslator.cs b/crypto/src/util/encoders/HexTranslator.cs
new file mode 100644
index 000000000..9775b6948
--- /dev/null
+++ b/crypto/src/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;
+        }
+    }
+
+}
diff --git a/crypto/src/util/encoders/IEncoder.cs b/crypto/src/util/encoders/IEncoder.cs
new file mode 100644
index 000000000..5887d5daa
--- /dev/null
+++ b/crypto/src/util/encoders/IEncoder.cs
@@ -0,0 +1,18 @@
+using System;
+using System.IO;
+
+namespace Org.BouncyCastle.Utilities.Encoders
+{
+	/**
+	 * Encode and decode byte arrays (typically from binary to 7-bit ASCII
+	 * encodings).
+	 */
+	public interface IEncoder
+	{
+		int Encode(byte[] data, int off, int length, Stream outStream);
+
+		int Decode(byte[] data, int off, int length, Stream outStream);
+
+		int DecodeString(string data, Stream outStream);
+	}
+}
diff --git a/crypto/src/util/encoders/Translator.cs b/crypto/src/util/encoders/Translator.cs
new file mode 100644
index 000000000..10bd24b63
--- /dev/null
+++ b/crypto/src/util/encoders/Translator.cs
@@ -0,0 +1,19 @@
+using System;
+
+namespace Org.BouncyCastle.Utilities.Encoders
+{
+    /// <summary>
+    /// Translator interface.
+    /// </summary>
+    public interface ITranslator
+    {
+        int GetEncodedBlockSize();
+
+        int Encode(byte[] input, int inOff, int length, byte[] outBytes, int outOff);
+
+        int GetDecodedBlockSize();
+
+        int Decode(byte[] input, int inOff, int length, byte[] outBytes, int outOff);
+    }
+
+}
diff --git a/crypto/src/util/encoders/UrlBase64.cs b/crypto/src/util/encoders/UrlBase64.cs
new file mode 100644
index 000000000..94195ef5e
--- /dev/null
+++ b/crypto/src/util/encoders/UrlBase64.cs
@@ -0,0 +1,127 @@
+using System;
+using System.IO;
+
+namespace Org.BouncyCastle.Utilities.Encoders
+{
+	/**
+	* Convert binary data to and from UrlBase64 encoding.  This is identical to
+	* Base64 encoding, except that the padding character is "." and the other 
+	* non-alphanumeric characters are "-" and "_" instead of "+" and "/".
+	* <p>
+	* The purpose of UrlBase64 encoding is to provide a compact encoding of binary
+	* data that is safe for use as an URL parameter. Base64 encoding does not
+	* produce encoded values that are safe for use in URLs, since "/" can be 
+	* interpreted as a path delimiter; "+" is the encoded form of a space; and
+	* "=" is used to separate a name from the corresponding value in an URL 
+	* parameter.
+	* </p>
+	*/
+	public class UrlBase64
+	{
+		private static readonly IEncoder encoder = new UrlBase64Encoder();
+
+		/**
+		* Encode the input data producing a URL safe base 64 encoded byte array.
+		*
+		* @return a byte array containing the URL safe base 64 encoded data.
+		*/
+		public static byte[] Encode(
+			byte[] data)
+		{
+			MemoryStream bOut = new MemoryStream();
+
+			try
+			{
+				encoder.Encode(data, 0, data.Length, bOut);
+			}
+			catch (IOException e)
+			{
+				throw new Exception("exception encoding URL safe base64 string: " + e.Message, e);
+			}
+
+			return bOut.ToArray();
+		}
+
+		/**
+		* Encode the byte data writing it to the given output stream.
+		*
+		* @return the number of bytes produced.
+		*/
+		public static int Encode(
+			byte[]	data,
+			Stream	outStr)
+		{
+			return encoder.Encode(data, 0, data.Length, outStr);
+		}
+
+		/**
+		* Decode the URL safe base 64 encoded input data - white space will be ignored.
+		*
+		* @return a byte array representing the decoded data.
+		*/
+		public static byte[] Decode(
+			byte[] data)
+		{
+			MemoryStream bOut = new MemoryStream();
+
+			try
+			{
+				encoder.Decode(data, 0, data.Length, bOut);
+			}
+			catch (IOException e)
+			{
+				throw new Exception("exception decoding URL safe base64 string: " + e.Message, e);
+			}
+
+			return bOut.ToArray();
+		}
+
+		/**
+		* decode the URL safe base 64 encoded byte data writing it to the given output stream,
+		* whitespace characters will be ignored.
+		*
+		* @return the number of bytes produced.
+		*/
+		public static int Decode(
+			byte[]	data,
+			Stream	outStr)
+		{
+			return encoder.Decode(data, 0, data.Length, outStr);
+		}
+
+		/**
+		* decode the URL safe base 64 encoded string data - whitespace will be ignored.
+		*
+		* @return a byte array representing the decoded data.
+		*/
+		public static byte[] Decode(
+			string data)
+		{
+			MemoryStream bOut = new MemoryStream();
+
+			try
+			{
+				encoder.DecodeString(data, bOut);
+			}
+			catch (IOException e)
+			{
+				throw new Exception("exception decoding URL safe base64 string: " + e.Message, e);
+			}
+	        
+			return bOut.ToArray();
+		}
+	    
+		/**
+		* Decode the URL safe base 64 encoded string data writing it to the given output stream,
+		* whitespace characters will be ignored.
+		*
+		* @return the number of bytes produced.
+		*/
+		public static int Decode(
+			string	data,
+			Stream	outStr)
+		{
+			return encoder.DecodeString(data, outStr);
+		}
+	}
+}
diff --git a/crypto/src/util/encoders/UrlBase64Encoder.cs b/crypto/src/util/encoders/UrlBase64Encoder.cs
new file mode 100644
index 000000000..5611a831c
--- /dev/null
+++ b/crypto/src/util/encoders/UrlBase64Encoder.cs
@@ -0,0 +1,31 @@
+using System;
+using System.IO;
+
+namespace Org.BouncyCastle.Utilities.Encoders
+{
+	/**
+	* Convert binary data to and from UrlBase64 encoding.  This is identical to
+	* Base64 encoding, except that the padding character is "." and the other 
+	* non-alphanumeric characters are "-" and "_" instead of "+" and "/".
+	* <p>
+	* The purpose of UrlBase64 encoding is to provide a compact encoding of binary
+	* data that is safe for use as an URL parameter. Base64 encoding does not
+	* produce encoded values that are safe for use in URLs, since "/" can be 
+	* interpreted as a path delimiter; "+" is the encoded form of a space; and
+	* "=" is used to separate a name from the corresponding value in an URL 
+	* parameter.
+	* </p>
+	*/
+	public class UrlBase64Encoder
+		: Base64Encoder
+	{
+		public UrlBase64Encoder()
+		{
+			encodingTable[encodingTable.Length - 2] = (byte) '-';
+			encodingTable[encodingTable.Length - 1] = (byte) '_';
+			padding = (byte) '.';
+			// we must re-create the decoding table with the new encoded values.
+			InitialiseDecodingTable();
+		}
+	}
+}
\ No newline at end of file