diff options
Diffstat (limited to 'crypto/src/util/encoders/HexEncoder.cs')
| -rw-r--r-- | crypto/src/util/encoders/HexEncoder.cs | 309 |
1 files changed, 161 insertions, 148 deletions
diff --git a/crypto/src/util/encoders/HexEncoder.cs b/crypto/src/util/encoders/HexEncoder.cs index e69a78b0b..af526e0da 100644 --- a/crypto/src/util/encoders/HexEncoder.cs +++ b/crypto/src/util/encoders/HexEncoder.cs @@ -3,56 +3,63 @@ 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; - } + public class HexEncoder + : IEncoder + { + protected 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' + }; + + /* + * set up the decoding table. + */ + protected readonly byte[] decodingTable = new byte[128]; + + protected void InitialiseDecodingTable() + { + Arrays.Fill(decodingTable, (byte)0xff); + + for (int i = 0; i < encodingTable.Length; i++) + { + decodingTable[encodingTable[i]] = (byte)i; + } + + decodingTable['A'] = decodingTable['a']; + decodingTable['B'] = decodingTable['b']; + decodingTable['C'] = decodingTable['c']; + decodingTable['D'] = decodingTable['d']; + decodingTable['E'] = decodingTable['e']; + decodingTable['F'] = decodingTable['f']; + } + + public HexEncoder() + { + InitialiseDecodingTable(); + } /** - * 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; - } + * 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) { @@ -60,104 +67,110 @@ namespace Org.BouncyCastle.Utilities.Encoders } /** - * 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; - } - } + * 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++]]; + + if ((b1 | b2) >= 0x80) + throw new IOException("invalid characters encountered in Hex data"); + + 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++]]; + + if ((b1 | b2) >= 0x80) + throw new IOException("invalid characters encountered in Hex data"); + + outStream.WriteByte((byte)((b1 << 4) | b2)); + + length++; + } + + return length; + } + } } |