//
// This file is part of the source code distribution of SharpPrivacy.
// SharpPrivacy is an Open Source OpenPGP implementation and can be
// found at http://www.sharpprivacy.net
// It is released under Gnu General Public License and can be used
// and modified as long as the result is released under GPL too.
// For a copy of the GPL, please go to www.gnu.org/copyleft/gpl.html
//
// Radix64.cs:
// Class for encoding/decoding Radix64 format.
//
// Author:
// Daniel Fabian (df@sharpprivacy.net)
//
//
// Version: 0.1.0 (initial release)
//
// Changelog:
// - 01.06.2003: Added this header for the first beta release.
//
// (C) 2003, Daniel Fabian
//
using System;
namespace SharpPrivacy.OpenPGP{
/// <summary>
/// The Radix64 class contains static methods that make
/// converting from and to Radix64 as defined in RFC 2440
/// easy.
/// </summary>
/// <remarks>
/// The Radix64 class contains static methods that make
/// converting from and to Radix64 as defined in RFC 2440
/// easy.
/// </remarks>
public class Radix64 : object {
// The table that makes it easy to calculate the CRC
private static long[] CRCTable = {
0x00000000, 0x00864cfb, 0x018ad50d, 0x010c99f6, 0x0393e6e1,
0x0315aa1a, 0x021933ec, 0x029f7f17, 0x07a18139, 0x0727cdc2,
0x062b5434, 0x06ad18cf, 0x043267d8, 0x04b42b23, 0x05b8b2d5,
0x053efe2e, 0x0fc54e89, 0x0f430272, 0x0e4f9b84, 0x0ec9d77f,
0x0c56a868, 0x0cd0e493, 0x0ddc7d65, 0x0d5a319e, 0x0864cfb0,
0x08e2834b, 0x09ee1abd, 0x09685646, 0x0bf72951, 0x0b7165aa,
0x0a7dfc5c, 0x0afbb0a7, 0x1f0cd1e9, 0x1f8a9d12, 0x1e8604e4,
0x1e00481f, 0x1c9f3708, 0x1c197bf3, 0x1d15e205, 0x1d93aefe,
0x18ad50d0, 0x182b1c2b, 0x192785dd, 0x19a1c926, 0x1b3eb631,
0x1bb8faca, 0x1ab4633c, 0x1a322fc7, 0x10c99f60, 0x104fd39b,
0x11434a6d, 0x11c50696, 0x135a7981, 0x13dc357a, 0x12d0ac8c,
0x1256e077, 0x17681e59, 0x17ee52a2, 0x16e2cb54, 0x166487af,
0x14fbf8b8, 0x147db443, 0x15712db5, 0x15f7614e, 0x3e19a3d2,
0x3e9fef29, 0x3f9376df, 0x3f153a24, 0x3d8a4533, 0x3d0c09c8,
0x3c00903e, 0x3c86dcc5, 0x39b822eb, 0x393e6e10, 0x3832f7e6,
0x38b4bb1d, 0x3a2bc40a, 0x3aad88f1, 0x3ba11107, 0x3b275dfc,
0x31dced5b, 0x315aa1a0, 0x30563856, 0x30d074ad, 0x324f0bba,
0x32c94741, 0x33c5deb7, 0x3343924c, 0x367d6c62, 0x36fb2099,
0x37f7b96f, 0x3771f594, 0x35ee8a83, 0x3568c678, 0x34645f8e,
0x34e21375, 0x2115723b, 0x21933ec0, 0x209fa736, 0x2019ebcd,
0x228694da, 0x2200d821, 0x230c41d7, 0x238a0d2c, 0x26b4f302,
0x2632bff9, 0x273e260f, 0x27b86af4, 0x252715e3, 0x25a15918,
0x24adc0ee, 0x242b8c15, 0x2ed03cb2, 0x2e567049, 0x2f5ae9bf,
0x2fdca544, 0x2d43da53, 0x2dc596a8, 0x2cc90f5e, 0x2c4f43a5,
0x2971bd8b, 0x29f7f170, 0x28fb6886, 0x287d247d, 0x2ae25b6a,
0x2a641791, 0x2b688e67, 0x2beec29c, 0x7c3347a4, 0x7cb50b5f,
0x7db992a9, 0x7d3fde52, 0x7fa0a145, 0x7f26edbe, 0x7e2a7448,
0x7eac38b3, 0x7b92c69d, 0x7b148a66, 0x7a181390, 0x7a9e5f6b,
0x7801207c, 0x78876c87, 0x798bf571, 0x790db98a, 0x73f6092d,
0x737045d6, 0x727cdc20, 0x72fa90db, 0x7065efcc, 0x70e3a337,
0x71ef3ac1, 0x7169763a, 0x74578814, 0x74d1c4ef, 0x75dd5d19,
0x755b11e2, 0x77c46ef5, 0x7742220e, 0x764ebbf8, 0x76c8f703,
0x633f964d, 0x63b9dab6, 0x62b54340, 0x62330fbb, 0x60ac70ac,
0x602a3c57, 0x6126a5a1, 0x61a0e95a, 0x649e1774, 0x64185b8f,
0x6514c279, 0x65928e82, 0x670df195, 0x678bbd6e, 0x66872498,
0x66016863, 0x6cfad8c4, 0x6c7c943f, 0x6d700dc9, 0x6df64132,
0x6f693e25, 0x6fef72de, 0x6ee3eb28, 0x6e65a7d3, 0x6b5b59fd,
0x6bdd1506, 0x6ad18cf0, 0x6a57c00b, 0x68c8bf1c, 0x684ef3e7,
0x69426a11, 0x69c426ea, 0x422ae476, 0x42aca88d, 0x43a0317b,
0x43267d80, 0x41b90297, 0x413f4e6c, 0x4033d79a, 0x40b59b61,
0x458b654f, 0x450d29b4, 0x4401b042, 0x4487fcb9, 0x461883ae,
0x469ecf55, 0x479256a3, 0x47141a58, 0x4defaaff, 0x4d69e604,
0x4c657ff2, 0x4ce33309, 0x4e7c4c1e, 0x4efa00e5, 0x4ff69913,
0x4f70d5e8, 0x4a4e2bc6, 0x4ac8673d, 0x4bc4fecb, 0x4b42b230,
0x49ddcd27, 0x495b81dc, 0x4857182a, 0x48d154d1, 0x5d26359f,
0x5da07964, 0x5cace092, 0x5c2aac69, 0x5eb5d37e, 0x5e339f85,
0x5f3f0673, 0x5fb94a88, 0x5a87b4a6, 0x5a01f85d, 0x5b0d61ab,
0x5b8b2d50, 0x59145247, 0x59921ebc, 0x589e874a, 0x5818cbb1,
0x52e37b16, 0x526537ed, 0x5369ae1b, 0x53efe2e0, 0x51709df7,
0x51f6d10c, 0x50fa48fa, 0x507c0401, 0x5542fa2f, 0x55c4b6d4,
0x54c82f22, 0x544e63d9, 0x56d11cce, 0x56575035, 0x575bc9c3,
0x57dd8538
};
/// <summary>
/// Encodes the given byte array according to Radix64 as
/// defined in RFC2440.
/// </summary>
/// <param name="bData">Byte array containing binary data</param>
/// <param name="bWithChecksum">If set to true, a checksum
/// is appended to the encoding.</param>
/// <param name="bTokenize">If set to true, the returned string
/// is split up into lines of 64 characters. If false, a single
/// line is returned.</param>
/// <returns>Returns the radix64 encoded data</returns>
/// <remarks>No remarks</remarks>
public static string Encode(byte[] bData, bool bWithChecksum) {
string strOutput = "";
int nGroups = bData.Length / 3;
strOutput = Convert.ToBase64String(bData);
string strTemp = "";
int iCount = 0;
while ((strOutput.Length - iCount*64) >64) {
strTemp += strOutput.Substring(iCount * 64, 64) + "\r\n";
iCount++;
}
strTemp += strOutput.Substring(iCount*64, strOutput.Length - iCount*64) + "\r\n";
strOutput = strTemp;
if (bWithChecksum) {
string strChecksum = CRC_Checksum(bData);
strOutput += "=" + strChecksum;
}
return strOutput;
}
/// <summary>Decodes the given Radix64-encoded String
/// to a byte array that is filled with the decoded binary
/// data.<br></br>
/// The parameter strData has to have a checksum appended.
/// This checksum is also verified.
/// </summary>
/// <exception cref="ApplicationException">
/// An ApplicationException is thrown when the parameter strData
/// did not have a checksum appended, or if the checksum was
/// incorrect.
/// </exception>
/// <param name="strData">Radix64 encoded String</param>
/// <returns>Returns a byte array containing the decoded
/// base64 data.</returns>
/// <remarks>No remarks</remarks>
public static byte[] Decode(string strData) {
//Get the checksum of the message
int nChecksumstart = strData.LastIndexOf('=');
string strCRC = "";
try {
strCRC = strData.Substring(nChecksumstart+1, 4);
} catch {
throw new System.ApplicationException("The Radix64 checksum was wrong!");
}
//Strip the checksum from the real message
strData = strData.Substring(0, nChecksumstart);
byte[] bData = Convert.FromBase64String(strData);
string strShouldCRC = Radix64.CRC_Checksum(bData).Trim();
if (strShouldCRC != strCRC) {
throw new System.ApplicationException("The Radix64 checksum was wrong!");
}
return bData;
}
/// <summary>
/// Dash escapes the given message. Dash escaping means,
/// that every line in a message starting with a dash (-)
/// ist prefixed with another dash and a space.
/// </summary>
/// <param name="strMessage">The message that is to be
/// dash escaped</param>
/// <returns>Returns the dash escaped message.</returns>
/// <remarks>No remarks</remarks>
public static string DashEscape(string strMessage) {
string[] strLines = strMessage.Split('\n');
for (int i=0; i<strLines.Length; i++) {
strLines[i] = strLines[i].TrimEnd(null);
if (strLines[i].Length > 0)
if (strLines[i].Substring(0, 1) == "-")
strLines[i] = "- " + strLines[i];
}
string strReturn = String.Join("\r\n", strLines);
return strReturn;
}
/// <summary>
/// Dash unescapes the given message. Dash escaping means,
/// that every line in a message starting with a dash (-)
/// ist prefixed with another dash and a space (- ).
/// </summary>
/// <param name="strMessage">The message that is to be
/// dash escaped</param>
/// <returns>Returns the dash escaped message.</returns>
/// <remarks>No remarks</remarks>
public static string DashUnescape(string strMessage) {
string[] strLines = strMessage.Split('\n');
for (int i=0; i<strLines.Length; i++) {
strLines[i] = strLines[i].TrimEnd(null);
if (strLines[i].Length > 1)
if (strLines[i].Substring(0, 2) == "- ")
strLines[i] = strLines[i].Substring(2, strLines[i].Length - 2);
}
string strReturn = String.Join("\r\n", strLines);
return strReturn;
}
/// <summary>Trims each line in the message.</summary>
/// <param name="strMessage">The message that should
/// be trimmed.</param>
/// <returns>Returns the trimmed message.</returns>
/// <remarks>No remarks</remarks>
public static string TrimMessage(string strMessage) {
string[] strLines = strMessage.Split('\n');
for (int i=0; i<strLines.Length; i++) {
strLines[i] = strLines[i].TrimEnd(null);
}
string strReturn = String.Join("\r\n", strLines);
return strReturn;
}
private static string CRC_Checksum(byte[] bData) {
long crc = 0xb704ce;
byte[] bCRC = new byte[3];
for (int i=0; i<bData.Length; i++)
crc = (crc << 8) ^ CRCTable[((crc >> 16) ^ bData[i]) & 0xff];
crc &= 0xffffff;
bCRC[0] = (byte)((crc & 0xFF0000) >> 16);
bCRC[1] = (byte)((crc & 0x00FF00) >> 8);
bCRC[2] = (byte)((crc & 0x0000FF));
return Radix64.Encode(bCRC, false);
}
}
}
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