// Copyright 2003-2015 Christian d'Heureuse, Inventec Informatik AG, Zurich, Switzerland // www.source-code.biz, www.inventec.ch/chdh // // This module is multi-licensed and may be used under the terms // of any of the following licenses: // // EPL, Eclipse Public License, V1.0 or later, http://www.eclipse.org/legal // LGPL, GNU Lesser General Public License, V2.1 or later, http://www.gnu.org/licenses/lgpl.html // GPL, GNU General Public License, V2 or later, http://www.gnu.org/licenses/gpl.html // AGPL, GNU Affero General Public License V3 or later, http://www.gnu.org/licenses/agpl.html // AL, Apache License, V2.0 or later, http://www.apache.org/licenses // BSD, BSD License, http://www.opensource.org/licenses/bsd-license.php // MIT, MIT License, http://www.opensource.org/licenses/MIT // // Please contact the author if you need another license. // This module is provided "as is", without warranties of any kind. // // Project home page: www.source-code.biz/base64coder // // Ported from Java to C# by Martins Andersons. using ArgumentException = System.ArgumentException; using Encoding = System.Text.Encoding; using Math = System.Math; using StringBuilder = System.Text.StringBuilder; namespace source_code_biz { /** * A Base64 encoder/decoder. * *
* This class is used to encode and decode data in Base64 format as described in RFC 1521.
*/
public class Base64Coder
{
// The line separator string of the operating system.
private static readonly string systemLineSeparator = System.Environment.NewLine;
static Base64Coder()
{
// map1
int i = 0;
for (char c = 'A'; c <= 'Z'; c++) map1[i++] = c;
for (char c = 'a'; c <= 'z'; c++) map1[i++] = c;
for (char c = '0'; c <= '9'; c++) map1[i++] = c;
map1[i++] = '+'; map1[i++] = '/';
// map2
for (i = 0; i < map2.Length; i++) map2[i] = unchecked((byte)-1);
for (i = 0; i < 64; i++) map2[map1[i]] = (byte)i;
}
// Mapping table from 6-bit nibbles to Base64 characters.
private static readonly char[] map1 = new char[64];
// Mapping table from Base64 characters to 6-bit nibbles.
private static readonly byte[] map2 = new byte[128];
/**
* Encodes a string into Base64 format.
* No blanks or line breaks are inserted.
* @param s A String to be encoded.
* @return A String containing the Base64 encoded data.
*/
public static string EncodeString(string s)
{
return new string(Encode(Encoding.UTF8.GetBytes(s)));
}
/**
* Encodes a byte array into Base 64 format and breaks the output into lines of 76 characters.
* @param in An array containing the data bytes to be encoded.
* @return A String containing the Base64 encoded data, broken into lines.
*/
public static string EncodeLines(byte[] input)
{
return EncodeLines(input, 0, input.Length, 76, systemLineSeparator);
}
/**
* Encodes a byte array into Base 64 format and breaks the output into lines.
* @param in An array containing the data bytes to be encoded.
* @param iOff Offset of the first byte in in
to be processed.
* @param iLen Number of bytes to be processed in in
, starting at iOff
.
* @param lineLen Line length for the output data. Should be a multiple of 4.
* @param lineSeparator The line separator to be used to separate the output lines.
* @return A String containing the Base64 encoded data, broken into lines.
*/
public static string EncodeLines(byte[] input, int iOff, int iLen, int lineLen, string lineSeparator)
{
int blockLen = (lineLen * 3) / 4;
if (blockLen <= 0) throw new ArgumentException();
int lines = (iLen + blockLen - 1) / blockLen;
int bufLen = ((iLen + 2) / 3) * 4 + lines * lineSeparator.Length;
StringBuilder buf = new StringBuilder(bufLen);
int ip = 0;
while (ip < iLen)
{
int l = Math.Min(iLen - ip, blockLen);
buf.Append(Encode(input, iOff + ip, l));
buf.Append(lineSeparator);
ip += l;
}
return buf.ToString();
}
/**
* Encodes a byte array into Base64 format.
* No blanks or line breaks are inserted in the output.
* @param in An array containing the data bytes to be encoded.
* @return A character array containing the Base64 encoded data.
*/
public static char[] Encode(byte[] input)
{
return Encode(input, 0, input.Length);
}
/**
* Encodes a byte array into Base64 format.
* No blanks or line breaks are inserted in the output.
* @param in An array containing the data bytes to be encoded.
* @param iLen Number of bytes to process in in
.
* @return A character array containing the Base64 encoded data.
*/
public static char[] Encode(byte[] input, int iLen)
{
return Encode(input, 0, iLen);
}
/**
* Encodes a byte array into Base64 format.
* No blanks or line breaks are inserted in the output.
* @param in An array containing the data bytes to be encoded.
* @param iOff Offset of the first byte in in
to be processed.
* @param iLen Number of bytes to process in in
, starting at iOff
.
* @return A character array containing the Base64 encoded data.
*/
public static char[] Encode(byte[] input, int iOff, int iLen)
{
int oDataLen = (iLen * 4 + 2) / 3; // output length without padding
int oLen = ((iLen + 2) / 3) * 4; // output length including padding
char[] output = new char[oLen];
int ip = iOff;
int iEnd = iOff + iLen;
int op = 0;
while (ip < iEnd)
{
int i0 = input[ip++];
int i1 = ip < iEnd ? input[ip++] : 0;
int i2 = ip < iEnd ? input[ip++] : 0;
int o0 = i0 >> 2;
int o1 = ((i0 & 3) << 4) | (i1 >> 4);
int o2 = ((i1 & 0xf) << 2) | (i2 >> 6);
int o3 = i2 & 0x3F;
output[op++] = map1[o0];
output[op++] = map1[o1];
output[op] = op < oDataLen ? map1[o2] : '='; op++;
output[op] = op < oDataLen ? map1[o3] : '='; op++;
}
return output;
}
/**
* Decodes a string from Base64 format.
* No blanks or line breaks are allowed within the Base64 encoded input data.
* @param s A Base64 String to be decoded.
* @return A String containing the decoded data.
* @throws ArgumentException If the input is not valid Base64 encoded data.
*/
public static string DecodeString(string s)
{
return Encoding.UTF8.GetString(Decode(s));
}
/**
* Decodes a byte array from Base64 format and ignores line separators, tabs and blanks.
* CR, LF, Tab and Space characters are ignored in the input data.
* @param s A Base64 String to be decoded.
* @return An array containing the decoded data bytes.
* @throws ArgumentException If the input is not valid Base64 encoded data.
*/
public static byte[] DecodeLines(string s)
{
char[] buf = new char[s.Length];
int p = 0;
for (int ip = 0; ip < s.Length; ip++)
{
char c = s[ip];
if (c != ' ' && c != '\r' && c != '\n' && c != '\t')
buf[p++] = c;
}
return Decode(buf, 0, p);
}
/**
* Decodes a byte array from Base64 format.
* No blanks or line breaks are allowed within the Base64 encoded input data.
* @param s A Base64 string to be decoded.
* @return An array containing the decoded data bytes.
* @throws ArgumentException If the input is not valid Base64 encoded data.
*/
public static byte[] Decode(string s)
{
return Decode(s.ToCharArray());
}
/**
* Decodes a byte array from Base64 format.
* No blanks or line breaks are allowed within the Base64 encoded input data.
* @param in A character array containing the Base64 encoded data.
* @return An array containing the decoded data bytes.
* @throws ArgumentException If the input is not valid Base64 encoded data.
*/
public static byte[] Decode(char[] input)
{
return Decode(input, 0, input.Length);
}
/**
* Decodes a byte array from Base64 format.
* No blanks or line breaks are allowed within the Base64 encoded input data.
* @param in A character array containing the Base64 encoded data.
* @param iOff Offset of the first character in in
to be processed.
* @param iLen Number of characters to process in in
, starting at iOff
.
* @return An array containing the decoded data bytes.
* @throws ArgumentException If the input is not valid Base64 encoded data.
*/
public static byte[] Decode(char[] input, int iOff, int iLen)
{
if (iLen % 4 != 0) throw new ArgumentException("Length of Base64 encoded input string is not a multiple of 4.");
while (iLen > 0 && input[iOff + iLen - 1] == '=') iLen--;
int oLen = (iLen * 3) / 4;
byte[] output = new byte[oLen];
int ip = iOff;
int iEnd = iOff + iLen;
int op = 0;
while (ip < iEnd)
{
int i0 = input[ip++];
int i1 = input[ip++];
int i2 = ip < iEnd ? input[ip++] : 'A';
int i3 = ip < iEnd ? input[ip++] : 'A';
if (i0 > 127 || i1 > 127 || i2 > 127 || i3 > 127)
throw new ArgumentException("Illegal character in Base64 encoded data.");
int b0 = map2[i0];
int b1 = map2[i1];
int b2 = map2[i2];
int b3 = map2[i3];
if (b0 < 0 || b1 < 0 || b2 < 0 || b3 < 0)
throw new ArgumentException("Illegal character in Base64 encoded data.");
int o0 = (b0 << 2) | (b1 >> 4);
int o1 = ((b1 & 0xf) << 4) | (b2 >> 2);
int o2 = ((b2 & 3) << 6) | b3;
output[op++] = (byte)o0;
if (op < oLen) output[op++] = (byte)o1;
if (op < oLen) output[op++] = (byte)o2;
}
return output;
}
}
}