/*This file is part of Socks via HTTP.This package is free software; you can redistribute it and/or modifyit under the terms of the GNU General Public License as published bythe Free Software Foundation; either version 2 of the License, or(at your option) any later version.Socks via HTTP is distributed in the hope that it will be useful,but WITHOUT ANY WARRANTY; without even the implied warranty ofMERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See theGNU General Public License for more details.You should have received a copy of the GNU General Public Licensealong with Socks via HTTP; if not, write to the Free SoftwareFoundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA*/// Title :        Base64Encoder.java// Version :      0.40// Copyright :    Copyright (c) 2001// Author :       Florent CUETO (fcueto@wanadoo.fr)// Description :  Base 64 Encoderpackage socks4;import java.io.*;/** * A class to encode Base64 streams and strings. * See RFC 1521 section 5.2 for details of the Base64 algorithm. * <p> * This class can be used for encoding strings: * <blockquote><pre> * String unencoded = "webmaster:try2gueSS"; * String encoded = Base64Encoder.encode(unencoded); * </pre></blockquote> * or for encoding streams: * <blockquote><pre> * OutputStream out = new Base64Encoder(System.out); * </pre></blockquote> */public class Base64Encoder extends FilterOutputStream {  private static final char[] chars = {    'A', 'B', 'C', 'D', 'E', 'F', 'G', 'H', 'I', 'J',    'K', 'L', 'M', 'N', 'O', 'P', 'Q', 'R', 'S', 'T',    'U', 'V', 'W', 'X', 'Y', 'Z', 'a', 'b', 'c', 'd',    'e', 'f', 'g', 'h', 'i', 'j', 'k', 'l', 'm', 'n',    'o', 'p', 'q', 'r', 's', 't', 'u', 'v', 'w', 'x',    'y', 'z', '0', '1', '2', '3', '4', '5', '6', '7',    '8', '9', '+', '/'  };  private int charCount;  private int carryOver;  /**   * Constructs a new Base64 encoder that writes output to the given   * OutputStream.   *   * @param out the output stream   */  public Base64Encoder(OutputStream out) {    super(out);  }  /**   * Writes the given byte to the output stream in an encoded form.   *   * @exception IOException if an I/O error occurs   */  public void write(int b) throws IOException {    // Take 24-bits from three octets, translate into four encoded chars    // Break lines at 76 chars    // If necessary, pad with 0 bits on the right at the end    // Use = signs as padding at the end to ensure encodedLength % 4 == 0    // Remove the sign bit,    // thanks to Christian Schweingruber <chrigu@lorraine.ch>    if (b < 0) {      b += 256;    }    // First byte use first six bits, save last two bits    if (charCount % 3 == 0) {      int lookup = b >> 2;      carryOver = b & 3;        // last two bits      out.write(chars[lookup]);    }    // Second byte use previous two bits and first four new bits,    // save last four bits    else if (charCount % 3 == 1) {      int lookup = ((carryOver << 4) + (b >> 4)) & 63;      carryOver = b & 15;       // last four bits      out.write(chars[lookup]);    }    // Third byte use previous four bits and first two new bits,    // then use last six new bits    else if (charCount % 3 == 2) {      int lookup = ((carryOver << 2) + (b >> 6)) & 63;      out.write(chars[lookup]);      lookup = b & 63;          // last six bits      out.write(chars[lookup]);      carryOver = 0;    }    charCount++;    // Add newline every 76 output chars (that's 57 input chars)    if (charCount % 57 == 0) {      out.write('\n');    }  }  /**   * Writes the given byte array to the output stream in an   * encoded form.   *   * @param b the data to be written   * @param off the start offset of the data   * @param len the length of the data   * @exception IOException if an I/O error occurs   */  public void write(byte[] b, int off, int len) throws IOException {    // This could of course be optimized    for (int i = 0; i < len; i++) {      write(b[off + i]);    }  }  /**   * Closes the stream, this MUST be called to ensure proper padding is   * written to the end of the output stream.   *   * @exception IOException if an I/O error occurs   */  public void close() throws IOException {    // Handle leftover bytes    if (charCount % 3 == 1) {  // one leftover      int lookup = (carryOver << 4) & 63;      out.write(chars[lookup]);      out.write('=');      out.write('=');    }    else if (charCount % 3 == 2) {  // two leftovers      int lookup = (carryOver << 2) & 63;      out.write(chars[lookup]);      out.write('=');    }    super.close();  }  /**   * Returns the encoded form of the given unencoded string.   *   * @param unencoded the string to encode   * @return the encoded form of the unencoded string   */  public static String encode(String unencoded) {    ByteArrayOutputStream out =      new ByteArrayOutputStream((int) (unencoded.length() * 1.37));    Base64Encoder encodedOut = new Base64Encoder(out);    byte[] bytes = null;    try {      bytes = unencoded.getBytes("8859_1");    }    catch (UnsupportedEncodingException ignored) { }    try {      encodedOut.write(bytes);      encodedOut.close();      return out.toString("8859_1");    }    catch (IOException ignored) { return null; }  }}