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