content: /*
   * Licensed to the Apache Software Foundation (ASF) under one
   * or more contributor license agreements.  See the NOTICE file
   * distributed with this work for additional information
   * regarding copyright ownership.  The ASF licenses this file
   * to you under the Apache License, Version 2.0 (the
   * "License"); you may not use this file except in compliance
   * with the License.  You may obtain a copy of the License at
   *
   * http://www.apache.org/licenses/LICENSE-2.0
   *
   * Unless required by applicable law or agreed to in writing,
   * software distributed under the License is distributed on an
   * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
   * KIND, either express or implied.  See the License for the
   * specific language governing permissions and limitations
   * under the License.
   */
  package org.apache.chemistry.opencmis.commons.impl;
  
  import org.slf4j.Logger;
  import org.slf4j.LoggerFactory;
  
  /**
   * <p>
   * Encodes and decodes to and from Base64 notation.
   * </p>
   * <p>
   * Homepage: <a href="http://iharder.net/base64">http://iharder.net/base64</a>.
   * </p>
   * 
   * @author Robert Harder
   * @author rob@iharder.net
   * @version 2.3.7
   */
  public final class Base64 {
  
      private static final Logger LOG = LoggerFactory.getLogger(Base64.class);
  
      /* ******** P U B L I C F I E L D S ******** */
  
      /** No options specified. Value is zero. */
      public static final int NO_OPTIONS = 0;
  
      /** Specify encoding in first bit. Value is one. */
      public static final int ENCODE = 1;
  
      /** Specify decoding in first bit. Value is zero. */
      public static final int DECODE = 0;
  
      /** Specify that data should be gzip-compressed in second bit. Value is two. */
      public static final int GZIP = 2;
  
      /**
       * Specify that gzipped data should <em>not</em> be automatically gunzipped.
       */
      public static final int DONT_GUNZIP = 4;
  
      /** Do break lines when encoding. Value is 8. */
      public static final int DO_BREAK_LINES = 8;
  
      /**
       * Encode using Base64-like encoding that is URL- and Filename-safe as
       * described in Section 4 of RFC3548: <a
       * href="http://www.faqs.org/rfcs/rfc3548.html"
       * >http://www.faqs.org/rfcs/rfc3548.html</a>. It is important to note that
       * data encoded this way is <em>not</em> officially valid Base64, or at the
       * very least should not be called Base64 without also specifying that is
       * was encoded using the URL- and Filename-safe dialect.
       */
      public static final int URL_SAFE = 16;
  
      /**
       * Encode using the special "ordered" dialect of Base64 described here: <a
       * href="http://www.faqs.org/qa/rfcc-1940.html">http://www.faqs.org/qa/rfcc-
       * 1940.html</a>.
       */
      public static final int ORDERED = 32;
  
      /* ******** P R I V A T E F I E L D S ******** */
  
      /** Maximum line length (76) of Base64 output. */
      private static final int MAX_LINE_LENGTH = 76;
  
      /** The equals sign (=) as a byte. */
      private static final byte EQUALS_SIGN = (byte) '=';
  
      /** The new line character (\n) as a byte. */
      private static final byte NEW_LINE = (byte) '\n';
  
      /** Preferred encoding. */
      private static final String PREFERRED_ENCODING = "US-ASCII";
  
      private static final byte WHITE_SPACE_ENC = -5; // Indicates white space in
                                                      // encoding
      private static final byte EQUALS_SIGN_ENC = -1; // Indicates equals sign in
      // encoding
  
      /* ******** S T A N D A R D B A S E 6 4 A L P H A B E T ******** */
  
      /** The 64 valid Base64 values. */
      /*
       * Host platform me be something funny like EBCDIC, so we hardcode these
       * values.
       */
      private static final byte[] _STANDARD_ALPHABET = { (byte) 'A', (byte) 'B', (byte) 'C', (byte) 'D', (byte) 'E',
              (byte) 'F', (byte) 'G', (byte) 'H', (byte) 'I', (byte) 'J', (byte) 'K', (byte) 'L', (byte) 'M', (byte) 'N',
              (byte) 'O', (byte) 'P', (byte) 'Q', (byte) 'R', (byte) 'S', (byte) 'T', (byte) 'U', (byte) 'V', (byte) 'W',
              (byte) 'X', (byte) 'Y', (byte) 'Z', (byte) 'a', (byte) 'b', (byte) 'c', (byte) 'd', (byte) 'e', (byte) 'f',
              (byte) 'g', (byte) 'h', (byte) 'i', (byte) 'j', (byte) 'k', (byte) 'l', (byte) 'm', (byte) 'n', (byte) 'o',
              (byte) 'p', (byte) 'q', (byte) 'r', (byte) 's', (byte) 't', (byte) 'u', (byte) 'v', (byte) 'w', (byte) 'x',
              (byte) 'y', (byte) 'z', (byte) '0', (byte) '1', (byte) '2', (byte) '3', (byte) '4', (byte) '5', (byte) '6',
              (byte) '7', (byte) '8', (byte) '9', (byte) '+', (byte) '/' };
  
      /**
       * Translates a Base64 value to either its 6-bit reconstruction value or a
       * negative number indicating some other meaning.
       **/
      private static final byte[] _STANDARD_DECODABET = { -9, -9, -9, -9, -9, -9, -9, -9, -9, // Decimal
                                                                                              // 0
                                                                                              // -
                                                                                              // 8
              -5, -5, // Whitespace: Tab and Linefeed
              -9, -9, // Decimal 11 - 12
              -5, // Whitespace: Carriage Return
              -9, -9, -9, -9, -9, -9, -9, -9, -9, -9, -9, -9, -9, // Decimal 14 -
                                                                  // 26
              -9, -9, -9, -9, -9, // Decimal 27 - 31
              -5, // Whitespace: Space
              -9, -9, -9, -9, -9, -9, -9, -9, -9, -9, // Decimal 33 - 42
              62, // Plus sign at decimal 43
              -9, -9, -9, // Decimal 44 - 46
              63, // Slash at decimal 47
              52, 53, 54, 55, 56, 57, 58, 59, 60, 61, // Numbers zero through nine
              -9, -9, -9, // Decimal 58 - 60
              -1, // Equals sign at decimal 61
              -9, -9, -9, // Decimal 62 - 64
              0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, // Letters 'A' through
                                                            // 'N'
              14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, // Letters 'O'
                                                              // through 'Z'
              -9, -9, -9, -9, -9, -9, // Decimal 91 - 96
              26, 27, 28, 29, 30, 31, 32, 33, 34, 35, 36, 37, 38, // Letters 'a'
                                                                  // through 'm'
              39, 40, 41, 42, 43, 44, 45, 46, 47, 48, 49, 50, 51, // Letters 'n'
                                                                  // through 'z'
              -9, -9, -9, -9, -9 // Decimal 123 - 127
              , -9, -9, -9, -9, -9, -9, -9, -9, -9, -9, -9, -9, // Decimal 128 -
                                                                // 139
              -9, -9, -9, -9, -9, -9, -9, -9, -9, -9, -9, -9, -9, // Decimal 140 -
                                                                  // 152
              -9, -9, -9, -9, -9, -9, -9, -9, -9, -9, -9, -9, -9, // Decimal 153 -
                                                                  // 165
              -9, -9, -9, -9, -9, -9, -9, -9, -9, -9, -9, -9, -9, // Decimal 166 -
                                                                  // 178
              -9, -9, -9, -9, -9, -9, -9, -9, -9, -9, -9, -9, -9, // Decimal 179 -
                                                                  // 191
              -9, -9, -9, -9, -9, -9, -9, -9, -9, -9, -9, -9, -9, // Decimal 192 -
                                                                  // 204
              -9, -9, -9, -9, -9, -9, -9, -9, -9, -9, -9, -9, -9, // Decimal 205 -
                                                                  // 217
              -9, -9, -9, -9, -9, -9, -9, -9, -9, -9, -9, -9, -9, // Decimal 218 -
                                                                  // 230
              -9, -9, -9, -9, -9, -9, -9, -9, -9, -9, -9, -9, -9, // Decimal 231 -
                                                                  // 243
              -9, -9, -9, -9, -9, -9, -9, -9, -9, -9, -9, -9 // Decimal 244 - 255
      };
  
      /* ******** U R L S A F E B A S E 6 4 A L P H A B E T ******** */
  
      /**
       * Used in the URL- and Filename-safe dialect described in Section 4 of
       * RFC3548: <a
       * href="http://www.faqs.org/rfcs/rfc3548.html">http://www.faqs.org
       * /rfcs/rfc3548.html</a>. Notice that the last two bytes become "hyphen"
       * and "underscore" instead of "plus" and "slash."
       */
      private static final byte[] _URL_SAFE_ALPHABET = { (byte) 'A', (byte) 'B', (byte) 'C', (byte) 'D', (byte) 'E',
              (byte) 'F', (byte) 'G', (byte) 'H', (byte) 'I', (byte) 'J', (byte) 'K', (byte) 'L', (byte) 'M', (byte) 'N',
              (byte) 'O', (byte) 'P', (byte) 'Q', (byte) 'R', (byte) 'S', (byte) 'T', (byte) 'U', (byte) 'V', (byte) 'W',
              (byte) 'X', (byte) 'Y', (byte) 'Z', (byte) 'a', (byte) 'b', (byte) 'c', (byte) 'd', (byte) 'e', (byte) 'f',
              (byte) 'g', (byte) 'h', (byte) 'i', (byte) 'j', (byte) 'k', (byte) 'l', (byte) 'm', (byte) 'n', (byte) 'o',
              (byte) 'p', (byte) 'q', (byte) 'r', (byte) 's', (byte) 't', (byte) 'u', (byte) 'v', (byte) 'w', (byte) 'x',
              (byte) 'y', (byte) 'z', (byte) '0', (byte) '1', (byte) '2', (byte) '3', (byte) '4', (byte) '5', (byte) '6',
              (byte) '7', (byte) '8', (byte) '9', (byte) '-', (byte) '_' };
  
      /**
       * Used in decoding URL- and Filename-safe dialects of Base64.
       */
      private static final byte[] _URL_SAFE_DECODABET = { -9, -9, -9, -9, -9, -9, -9, -9, -9, // Decimal
                                                                                              // 0
                                                                                              // -
                                                                                              // 8
              -5, -5, // Whitespace: Tab and Linefeed
              -9, -9, // Decimal 11 - 12
              -5, // Whitespace: Carriage Return
              -9, -9, -9, -9, -9, -9, -9, -9, -9, -9, -9, -9, -9, // Decimal 14 -
                                                                  // 26
              -9, -9, -9, -9, -9, // Decimal 27 - 31
              -5, // Whitespace: Space
              -9, -9, -9, -9, -9, -9, -9, -9, -9, -9, // Decimal 33 - 42
              -9, // Plus sign at decimal 43
              -9, // Decimal 44
              62, // Minus sign at decimal 45
              -9, // Decimal 46
              -9, // Slash at decimal 47
              52, 53, 54, 55, 56, 57, 58, 59, 60, 61, // Numbers zero through nine
              -9, -9, -9, // Decimal 58 - 60
              -1, // Equals sign at decimal 61
              -9, -9, -9, // Decimal 62 - 64
              0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, // Letters 'A' through
                                                            // 'N'
              14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, // Letters 'O'
                                                              // through 'Z'
              -9, -9, -9, -9, // Decimal 91 - 94
              63, // Underscore at decimal 95
              -9, // Decimal 96
              26, 27, 28, 29, 30, 31, 32, 33, 34, 35, 36, 37, 38, // Letters 'a'
                                                                  // through 'm'
              39, 40, 41, 42, 43, 44, 45, 46, 47, 48, 49, 50, 51, // Letters 'n'
                                                                  // through 'z'
              -9, -9, -9, -9, -9 // Decimal 123 - 127
              , -9, -9, -9, -9, -9, -9, -9, -9, -9, -9, -9, -9, // Decimal 128 -
                                                                // 139
              -9, -9, -9, -9, -9, -9, -9, -9, -9, -9, -9, -9, -9, // Decimal 140 -
                                                                  // 152
              -9, -9, -9, -9, -9, -9, -9, -9, -9, -9, -9, -9, -9, // Decimal 153 -
                                                                  // 165
              -9, -9, -9, -9, -9, -9, -9, -9, -9, -9, -9, -9, -9, // Decimal 166 -
                                                                  // 178
              -9, -9, -9, -9, -9, -9, -9, -9, -9, -9, -9, -9, -9, // Decimal 179 -
                                                                  // 191
              -9, -9, -9, -9, -9, -9, -9, -9, -9, -9, -9, -9, -9, // Decimal 192 -
                                                                  // 204
              -9, -9, -9, -9, -9, -9, -9, -9, -9, -9, -9, -9, -9, // Decimal 205 -
                                                                  // 217
              -9, -9, -9, -9, -9, -9, -9, -9, -9, -9, -9, -9, -9, // Decimal 218 -
                                                                  // 230
              -9, -9, -9, -9, -9, -9, -9, -9, -9, -9, -9, -9, -9, // Decimal 231 -
                                                                  // 243
              -9, -9, -9, -9, -9, -9, -9, -9, -9, -9, -9, -9 // Decimal 244 - 255
      };
  
      /* ******** O R D E R E D B A S E 6 4 A L P H A B E T ******** */
  
      /**
       * I don't get the point of this technique, but someone requested it, and it
       * is described here: <a
       * href="http://www.faqs.org/qa/rfcc-1940.html">http://
       * www.faqs.org/qa/rfcc-1940.html</a>.
       */
      private static final byte[] _ORDERED_ALPHABET = { (byte) '-', (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', (byte) 'G', (byte) 'H', (byte) 'I', (byte) 'J', (byte) 'K', (byte) 'L',
              (byte) 'M', (byte) 'N', (byte) 'O', (byte) 'P', (byte) 'Q', (byte) 'R', (byte) 'S', (byte) 'T', (byte) 'U',
              (byte) 'V', (byte) 'W', (byte) 'X', (byte) 'Y', (byte) 'Z', (byte) '_', (byte) 'a', (byte) 'b', (byte) 'c',
              (byte) 'd', (byte) 'e', (byte) 'f', (byte) 'g', (byte) 'h', (byte) 'i', (byte) 'j', (byte) 'k', (byte) 'l',
              (byte) 'm', (byte) 'n', (byte) 'o', (byte) 'p', (byte) 'q', (byte) 'r', (byte) 's', (byte) 't', (byte) 'u',
              (byte) 'v', (byte) 'w', (byte) 'x', (byte) 'y', (byte) 'z' };
  
      /**
       * Used in decoding the "ordered" dialect of Base64.
       */
      private static final byte[] _ORDERED_DECODABET = { -9, -9, -9, -9, -9, -9, -9, -9, -9, // Decimal
                                                                                             // 0
                                                                                             // -
                                                                                             // 8
              -5, -5, // Whitespace: Tab and Linefeed
              -9, -9, // Decimal 11 - 12
              -5, // Whitespace: Carriage Return
              -9, -9, -9, -9, -9, -9, -9, -9, -9, -9, -9, -9, -9, // Decimal 14 -
                                                                  // 26
              -9, -9, -9, -9, -9, // Decimal 27 - 31
              -5, // Whitespace: Space
              -9, -9, -9, -9, -9, -9, -9, -9, -9, -9, // Decimal 33 - 42
              -9, // Plus sign at decimal 43
              -9, // Decimal 44
              0, // Minus sign at decimal 45
              -9, // Decimal 46
              -9, // Slash at decimal 47
              1, 2, 3, 4, 5, 6, 7, 8, 9, 10, // Numbers zero through nine
              -9, -9, -9, // Decimal 58 - 60
              -1, // Equals sign at decimal 61
              -9, -9, -9, // Decimal 62 - 64
              11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, // Letters 'A'
                                                                  // through 'M'
              24, 25, 26, 27, 28, 29, 30, 31, 32, 33, 34, 35, 36, // Letters 'N'
                                                                  // through 'Z'
              -9, -9, -9, -9, // Decimal 91 - 94
              37, // Underscore at decimal 95
              -9, // Decimal 96
              38, 39, 40, 41, 42, 43, 44, 45, 46, 47, 48, 49, 50, // Letters 'a'
                                                                  // through 'm'
              51, 52, 53, 54, 55, 56, 57, 58, 59, 60, 61, 62, 63, // Letters 'n'
                                                                  // through 'z'
              -9, -9, -9, -9, -9 // Decimal 123 - 127
              , -9, -9, -9, -9, -9, -9, -9, -9, -9, -9, -9, -9, -9, // Decimal 128
                                                                    // - 139
              -9, -9, -9, -9, -9, -9, -9, -9, -9, -9, -9, -9, -9, // Decimal 140 -
                                                                  // 152
              -9, -9, -9, -9, -9, -9, -9, -9, -9, -9, -9, -9, -9, // Decimal 153 -
                                                                  // 165
              -9, -9, -9, -9, -9, -9, -9, -9, -9, -9, -9, -9, -9, // Decimal 166 -
                                                                  // 178
              -9, -9, -9, -9, -9, -9, -9, -9, -9, -9, -9, -9, -9, // Decimal 179 -
                                                                  // 191
              -9, -9, -9, -9, -9, -9, -9, -9, -9, -9, -9, -9, -9, // Decimal 192 -
                                                                  // 204
              -9, -9, -9, -9, -9, -9, -9, -9, -9, -9, -9, -9, -9, // Decimal 205 -
                                                                  // 217
              -9, -9, -9, -9, -9, -9, -9, -9, -9, -9, -9, -9, -9, // Decimal 218 -
                                                                  // 230
              -9, -9, -9, -9, -9, -9, -9, -9, -9, -9, -9, -9, -9, // Decimal 231 -
                                                                  // 243
              -9, -9, -9, -9, -9, -9, -9, -9, -9, -9, -9, -9 // Decimal 244 - 255
      };
  
      /* ******** D E T E R M I N E W H I C H A L H A B E T ******** */
  
      /**
       * Returns one of the _SOMETHING_ALPHABET byte arrays depending on the
       * options specified. It's possible, though silly, to specify ORDERED
       * <b>and</b> URLSAFE in which case one of them will be picked, though there
       * is no guarantee as to which one will be picked.
       */
      private static byte[] getAlphabet(int options) {
          if ((options & URL_SAFE) == URL_SAFE) {
              return _URL_SAFE_ALPHABET;
          } else if ((options & ORDERED) == ORDERED) {
              return _ORDERED_ALPHABET;
          } else {
              return _STANDARD_ALPHABET;
          }
      } // end getAlphabet
  
      /**
       * Returns one of the _SOMETHING_DECODABET byte arrays depending on the
       * options specified. It's possible, though silly, to specify ORDERED and
       * URL_SAFE in which case one of them will be picked, though there is no
       * guarantee as to which one will be picked.
       */
      private static byte[] getDecodabet(int options) {
          if ((options & URL_SAFE) == URL_SAFE) {
              return _URL_SAFE_DECODABET;
          } else if ((options & ORDERED) == ORDERED) {
              return _ORDERED_DECODABET;
          } else {
              return _STANDARD_DECODABET;
          }
      } // end getAlphabet
  
      /** Defeats instantiation. */
      private Base64() {
      }
  
      /* ******** E N C O D I N G M E T H O D S ******** */
  
      /**
       * Encodes up to the first three bytes of array <var>threeBytes</var> and
       * returns a four-byte array in Base64 notation. The actual number of
       * significant bytes in your array is given by <var>numSigBytes</var>. The
       * array <var>threeBytes</var> needs only be as big as
       * <var>numSigBytes</var>. Code can reuse a byte array by passing a
       * four-byte array as <var>b4</var>.
       * 
       * @param b4
       *            A reusable byte array to reduce array instantiation
       * @param threeBytes
       *            the array to convert
       * @param numSigBytes
       *            the number of significant bytes in your array
       * @return four byte array in Base64 notation.
       * @since 1.5.1
       */
      private static byte[] encode3to4(byte[] b4, byte[] threeBytes, int numSigBytes, int options) {
          encode3to4(threeBytes, 0, numSigBytes, b4, 0, options);
          return b4;
      } // end encode3to4
  
      /**
       * <p>
       * Encodes up to three bytes of the array <var>source</var> and writes the
       * resulting four Base64 bytes to <var>destination</var>. The source and
       * destination arrays can be manipulated anywhere along their length by
       * specifying <var>srcOffset</var> and <var>destOffset</var>. This method
       * does not check to make sure your arrays are large enough to accomodate
       * <var>srcOffset</var> + 3 for the <var>source</var> array or
       * <var>destOffset</var> + 4 for the <var>destination</var> array. The
       * actual number of significant bytes in your array is given by
       * <var>numSigBytes</var>.
       * </p>
       * <p>
       * This is the lowest level of the encoding methods with all possible
       * parameters.
       * </p>
       * 
       * @param source
       *            the array to convert
       * @param srcOffset
       *            the index where conversion begins
       * @param numSigBytes
       *            the number of significant bytes in your array
       * @param destination
       *            the array to hold the conversion
       * @param destOffset
       *            the index where output will be put
       * @return the <var>destination</var> array
       * @since 1.3
       */
      private static byte[] encode3to4(byte[] source, int srcOffset, int numSigBytes, byte[] destination, int destOffset,
              int options) {
  
          byte[] ALPHABET = getAlphabet(options);
  
          // 1 2 3
          // 01234567890123456789012345678901 Bit position
          // --------000000001111111122222222 Array position from threeBytes
          // --------| || || || | Six bit groups to index ALPHABET
          // >>18 >>12 >> 6 >> 0 Right shift necessary
          // 0x3f 0x3f 0x3f Additional AND
  
          // Create buffer with zero-padding if there are only one or two
          // significant bytes passed in the array.
          // We have to shift left 24 in order to flush out the 1's that appear
          // when Java treats a value as negative that is cast from a byte to an
          // int.
          int inBuff = (numSigBytes > 0 ? ((source[srcOffset] << 24) >>> 8) : 0)
                  | (numSigBytes > 1 ? ((source[srcOffset + 1] << 24) >>> 16) : 0)
                  | (numSigBytes > 2 ? ((source[srcOffset + 2] << 24) >>> 24) : 0);
  
          switch (numSigBytes) {
          case 3:
              destination[destOffset] = ALPHABET[(inBuff >>> 18)];
              destination[destOffset + 1] = ALPHABET[(inBuff >>> 12) & 0x3f];
              destination[destOffset + 2] = ALPHABET[(inBuff >>> 6) & 0x3f];
              destination[destOffset + 3] = ALPHABET[(inBuff) & 0x3f];
              return destination;
  
          case 2:
              destination[destOffset] = ALPHABET[(inBuff >>> 18)];
              destination[destOffset + 1] = ALPHABET[(inBuff >>> 12) & 0x3f];
              destination[destOffset + 2] = ALPHABET[(inBuff >>> 6) & 0x3f];
              destination[destOffset + 3] = EQUALS_SIGN;
              return destination;
  
          case 1:
              destination[destOffset] = ALPHABET[(inBuff >>> 18)];
              destination[destOffset + 1] = ALPHABET[(inBuff >>> 12) & 0x3f];
              destination[destOffset + 2] = EQUALS_SIGN;
              destination[destOffset + 3] = EQUALS_SIGN;
              return destination;
  
          default:
              return destination;
          } // end switch
      } // end encode3to4
  
      /**
       * Performs Base64 encoding on the <code>raw</code> ByteBuffer, writing it
       * to the <code>encoded</code> ByteBuffer. This is an experimental feature.
       * Currently it does not pass along any options (such as
       * {@link #DO_BREAK_LINES} or {@link #GZIP}.
       * 
       * @param raw
       *            input buffer
       * @param encoded
       *            output buffer
       * @since 2.3
       */
      public static void encode(java.nio.ByteBuffer raw, java.nio.ByteBuffer encoded) {
          byte[] raw3 = new byte[3];
          byte[] enc4 = new byte[4];
  
          while (raw.hasRemaining()) {
              int rem = Math.min(3, raw.remaining());
              raw.get(raw3, 0, rem);
              Base64.encode3to4(enc4, raw3, rem, Base64.NO_OPTIONS);
              encoded.put(enc4);
          } // end input remaining
      }
  
      /**
       * Performs Base64 encoding on the <code>raw</code> ByteBuffer, writing it
       * to the <code>encoded</code> CharBuffer. This is an experimental feature.
       * Currently it does not pass along any options (such as
       * {@link #DO_BREAK_LINES} or {@link #GZIP}.
       * 
       * @param raw
       *            input buffer
       * @param encoded
       *            output buffer
       * @since 2.3
       */
      public static void encode(java.nio.ByteBuffer raw, java.nio.CharBuffer encoded) {
          byte[] raw3 = new byte[3];
          byte[] enc4 = new byte[4];
  
          while (raw.hasRemaining()) {
              int rem = Math.min(3, raw.remaining());
              raw.get(raw3, 0, rem);
              Base64.encode3to4(enc4, raw3, rem, Base64.NO_OPTIONS);
              for (int i = 0; i < 4; i++) {
                  encoded.put((char) (enc4[i] & 0xFF));
              }
          } // end input remaining
      }
  
      /**
       * Serializes an object and returns the Base64-encoded version of that
       * serialized object.
       * 
       * <p>
       * As of v 2.3, if the object cannot be serialized or there is another
       * error, the method will throw an java.io.IOException. <b>This is new to
       * v2.3!</b> In earlier versions, it just returned a null value, but in
       * retrospect that's a pretty poor way to handle it.
       * </p>
       * 
       * The object is not GZip-compressed before being encoded.
       * 
       * @param serializableObject
       *            The object to encode
       * @return The Base64-encoded object
       * @throws java.io.IOException
       *             if there is an error
       * @throws NullPointerException
       *             if serializedObject is null
       * @since 1.4
       */
      public static String encodeObject(java.io.Serializable serializableObject) throws java.io.IOException {
          return encodeObject(serializableObject, NO_OPTIONS);
      } // end encodeObject
  
      /**
       * Serializes an object and returns the Base64-encoded version of that
       * serialized object.
       * 
       * <p>
       * As of v 2.3, if the object cannot be serialized or there is another
       * error, the method will throw an java.io.IOException. <b>This is new to
       * v2.3!</b> In earlier versions, it just returned a null value, but in
       * retrospect that's a pretty poor way to handle it.
       * </p>
       * 
       * The object is not GZip-compressed before being encoded.
       * <p>
       * Example options:
       * 
       * <pre>
       *   GZIP: gzip-compresses object before encoding it.
       *   DO_BREAK_LINES: break lines at 76 characters
       * </pre>
       * <p>
       * Example: <code>encodeObject( myObj, Base64.GZIP )</code> or
       * <p>
       * Example:
       * <code>encodeObject( myObj, Base64.GZIP | Base64.DO_BREAK_LINES )</code>
       * 
       * @param serializableObject
       *            The object to encode
       * @param options
       *            Specified options
       * @return The Base64-encoded object
       * @see Base64#GZIP
       * @see Base64#DO_BREAK_LINES
       * @throws java.io.IOException
       *             if there is an error
       * @since 2.0
       */
      public static String encodeObject(java.io.Serializable serializableObject, int options) throws java.io.IOException {
  
          if (serializableObject == null) {
              throw new NullPointerException("Cannot serialize a null object.");
          } // end if: null
  
          // Streams
          java.io.ByteArrayOutputStream baos = null;
          java.io.OutputStream b64os = null;
          java.util.zip.GZIPOutputStream gzos = null;
          java.io.ObjectOutputStream oos = null;
  
          try {
              // ObjectOutputStream -> (GZIP) -> Base64 -> ByteArrayOutputStream
              baos = new java.io.ByteArrayOutputStream();
              b64os = new Base64.OutputStream(baos, ENCODE | options);
              if ((options & GZIP) != 0) {
                  // Gzip
                  gzos = new java.util.zip.GZIPOutputStream(b64os);
                  oos = new java.io.ObjectOutputStream(gzos);
              } else {
                  // Not gzipped
                  oos = new java.io.ObjectOutputStream(b64os);
              }
              oos.writeObject(serializableObject);
          } // end try
          catch (java.io.IOException e) {
              // Catch it and then throw it immediately so that
              // the finally{} block is called for cleanup.
              throw e;
          } // end catch
          finally {
              IOUtils.closeQuietly(oos);
              IOUtils.closeQuietly(gzos);
              IOUtils.closeQuietly(b64os);
              IOUtils.closeQuietly(baos);
          } // end finally
  
          // Return value according to relevant encoding.
          try {
              return new String(baos.toByteArray(), PREFERRED_ENCODING);
          } // end try
          catch (java.io.UnsupportedEncodingException uue) {
              // Fall back to UTF-8
              return IOUtils.toUTF8String(baos.toByteArray());
          } // end catch
  
      } // end encode
  
      /**
       * Encodes a byte array into Base64 notation. Does not GZip-compress data.
       * 
       * @param source
       *            The data to convert
       * @return The data in Base64-encoded form
       * @throws NullPointerException
       *             if source array is null
       * @since 1.4
       */
      public static String encodeBytes(byte[] source) {
          // Since we're not going to have the GZIP encoding turned on,
          // we're not going to have an java.io.IOException thrown, so
          // we should not force the user to have to catch it.
          String encoded = null;
          try {
              encoded = encodeBytes(source, 0, source.length, NO_OPTIONS);
          } catch (java.io.IOException ex) {
              assert false : ex.getMessage();
          } // end catch
          assert encoded != null;
          return encoded;
      } // end encodeBytes
  
      /**
       * Encodes a byte array into Base64 notation.
       * <p>
       * Example options:
       * 
       * <pre>
       *   GZIP: gzip-compresses object before encoding it.
       *   DO_BREAK_LINES: break lines at 76 characters
       *     <i>Note: Technically, this makes your encoding non-compliant.</i>
       * </pre>
       * <p>
       * Example: <code>encodeBytes( myData, Base64.GZIP )</code> or
       * <p>
       * Example:
       * <code>encodeBytes( myData, Base64.GZIP | Base64.DO_BREAK_LINES )</code>
       * 
       * 
       * <p>
       * As of v 2.3, if there is an error with the GZIP stream, the method will
       * throw an java.io.IOException. <b>This is new to v2.3!</b> In earlier
       * versions, it just returned a null value, but in retrospect that's a
       * pretty poor way to handle it.
       * </p>
       * 
       * 
       * @param source
       *            The data to convert
       * @param options
       *            Specified options
       * @return The Base64-encoded data as a String
       * @see Base64#GZIP
       * @see Base64#DO_BREAK_LINES
       * @throws java.io.IOException
       *             if there is an error
       * @throws NullPointerException
       *             if source array is null
       * @since 2.0
       */
      public static String encodeBytes(byte[] source, int options) throws java.io.IOException {
          return encodeBytes(source, 0, source.length, options);
      } // end encodeBytes
  
      /**
       * Encodes a byte array into Base64 notation. Does not GZip-compress data.
       * 
       * <p>
       * As of v 2.3, if there is an error, the method will throw an
       * java.io.IOException. <b>This is new to v2.3!</b> In earlier versions, it
       * just returned a null value, but in retrospect that's a pretty poor way to
       * handle it.
       * </p>
       * 
       * 
       * @param source
       *            The data to convert
       * @param off
       *            Offset in array where conversion should begin
       * @param len
       *            Length of data to convert
       * @return The Base64-encoded data as a String
       * @throws NullPointerException
       *             if source array is null
       * @throws IllegalArgumentException
       *             if source array, offset, or length are invalid
       * @since 1.4
       */
      public static String encodeBytes(byte[] source, int off, int len) {
          // Since we're not going to have the GZIP encoding turned on,
          // we're not going to have an java.io.IOException thrown, so
          // we should not force the user to have to catch it.
          String encoded = null;
          try {
              encoded = encodeBytes(source, off, len, NO_OPTIONS);
          } catch (java.io.IOException ex) {
              assert false : ex.getMessage();
          } // end catch
          assert encoded != null;
          return encoded;
      } // end encodeBytes
  
      /**
       * Encodes a byte array into Base64 notation.
       * <p>
       * Example options:
       * 
       * <pre>
       *   GZIP: gzip-compresses object before encoding it.
       *   DO_BREAK_LINES: break lines at 76 characters
       *     <i>Note: Technically, this makes your encoding non-compliant.</i>
       * </pre>
       * <p>
       * Example: <code>encodeBytes( myData, Base64.GZIP )</code> or
       * <p>
       * Example:
       * <code>encodeBytes( myData, Base64.GZIP | Base64.DO_BREAK_LINES )</code>
       * 
       * 
       * <p>
       * As of v 2.3, if there is an error with the GZIP stream, the method will
       * throw an java.io.IOException. <b>This is new to v2.3!</b> In earlier
       * versions, it just returned a null value, but in retrospect that's a
       * pretty poor way to handle it.
       * </p>
       * 
       * 
       * @param source
       *            The data to convert
       * @param off
       *            Offset in array where conversion should begin
       * @param len
       *            Length of data to convert
       * @param options
       *            Specified options
       * @return The Base64-encoded data as a String
       * @see Base64#GZIP
       * @see Base64#DO_BREAK_LINES
       * @throws java.io.IOException
       *             if there is an error
       * @throws NullPointerException
       *             if source array is null
       * @throws IllegalArgumentException
       *             if source array, offset, or length are invalid
       * @since 2.0
       */
      public static String encodeBytes(byte[] source, int off, int len, int options) throws java.io.IOException {
          byte[] encoded = encodeBytesToBytes(source, off, len, options);
  
          // Return value according to relevant encoding.
          try {
              return new String(encoded, PREFERRED_ENCODING);
          } // end try
          catch (java.io.UnsupportedEncodingException uue) {
              return IOUtils.toUTF8String(encoded);
          } // end catch
  
      } // end encodeBytes
  
      /**
       * Similar to {@link #encodeBytes(byte[])} but returns a byte array instead
       * of instantiating a String. This is more efficient if you're working with
       * I/O streams and have large data sets to encode.
       * 
       * 
       * @param source
       *            The data to convert
       * @return The Base64-encoded data as a byte[] (of ASCII characters)
       * @throws NullPointerException
       *             if source array is null
       * @since 2.3.1
       */
      public static byte[] encodeBytesToBytes(byte[] source) {
          byte[] encoded = null;
          try {
              encoded = encodeBytesToBytes(source, 0, source.length, Base64.NO_OPTIONS);
          } catch (java.io.IOException ex) {
              assert false : "IOExceptions only come from GZipping, which is turned off: " + ex.getMessage();
          }
          return encoded;
      }
  
      /**
       * Similar to {@link #encodeBytes(byte[], int, int, int)} but returns a byte
       * array instead of instantiating a String. This is more efficient if you're
       * working with I/O streams and have large data sets to encode.
       * 
       * 
       * @param source
       *            The data to convert
       * @param off
       *            Offset in array where conversion should begin
       * @param len
       *            Length of data to convert
       * @param options
       *            Specified options
       * @return The Base64-encoded data as a String
       * @see Base64#GZIP
       * @see Base64#DO_BREAK_LINES
       * @throws java.io.IOException
       *             if there is an error
       * @throws NullPointerException
       *             if source array is null
       * @throws IllegalArgumentException
       *             if source array, offset, or length are invalid
       * @since 2.3.1
       */
      public static byte[] encodeBytesToBytes(byte[] source, int off, int len, int options) throws java.io.IOException {
  
          if (source == null) {
              throw new NullPointerException("Cannot serialize a null array.");
          } // end if: null
  
          if (off < 0) {
              throw new IllegalArgumentException("Cannot have negative offset: " + off);
          } // end if: off < 0
  
          if (len < 0) {
              throw new IllegalArgumentException("Cannot have length offset: " + len);
          } // end if: len < 0
  
          if (off + len > source.length) {
              throw new IllegalArgumentException(String.format(
                      "Cannot have offset of %d and length of %d with array of length %d", off, len, source.length));
          } // end if: off < 0
  
          // Compress?
          if ((options & GZIP) != 0) {
              java.io.ByteArrayOutputStream baos = null;
              java.util.zip.GZIPOutputStream gzos = null;
              Base64.OutputStream b64os = null;
  
              try {
                  // GZip -> Base64 -> ByteArray
                  baos = new java.io.ByteArrayOutputStream();
                  b64os = new Base64.OutputStream(baos, ENCODE | options);
                  gzos = new java.util.zip.GZIPOutputStream(b64os);
  
                  gzos.write(source, off, len);
                  gzos.close();
              } // end try
              catch (java.io.IOException e) {
                  // Catch it and then throw it immediately so that
                  // the finally{} block is called for cleanup.
                  throw e;
              } // end catch
              finally {
                  IOUtils.closeQuietly(gzos);
                  IOUtils.closeQuietly(b64os);
                  IOUtils.closeQuietly(baos);
              } // end finally
  
              return baos.toByteArray();
          } // end if: compress
  
          // Else, don't compress. Better not to use streams at all then.
          else {
              boolean breakLines = (options & DO_BREAK_LINES) != 0;
  
              // int len43 = len * 4 / 3;
              // byte[] outBuff = new byte[ ( len43 ) // Main 4:3
              // + ( (len % 3) > 0 ? 4 : 0 ) // Account for padding
              // + (breakLines ? ( len43 / MAX_LINE_LENGTH ) : 0) ]; // New lines
              // Try to determine more precisely how big the array needs to be.
              // If we get it right, we don't have to do an array copy, and
              // we save a bunch of memory.
              int encLen = (len / 3) * 4 + (len % 3 > 0 ? 4 : 0); // Bytes needed
                                                                  // for actual
                                                                  // encoding
              if (breakLines) {
                  encLen += encLen / MAX_LINE_LENGTH; // Plus extra newline
                                                      // characters
              }
              byte[] outBuff = new byte[encLen];
  
              int d = 0;
              int e = 0;
              int len2 = len - 2;
              int lineLength = 0;
              for (; d < len2; d += 3, e += 4) {
                  encode3to4(source, d + off, 3, outBuff, e, options);
  
                  lineLength += 4;
                  if (breakLines && lineLength >= MAX_LINE_LENGTH) {
                      outBuff[e + 4] = NEW_LINE;
                      e++;
                      lineLength = 0;
                  } // end if: end of line
              } // en dfor: each piece of array
  
              if (d < len) {
                  encode3to4(source, d + off, len - d, outBuff, e, options);
                  e += 4;
              } // end if: some padding needed
  
              // Only resize array if we didn't guess it right.
              if (e <= outBuff.length - 1) {
                  // If breaking lines and the last byte falls right at
                  // the line length (76 bytes per line), there will be
                  // one extra byte, and the array will need to be resized.
                  // Not too bad of an estimate on array size, I'd say.
                  byte[] finalOut = new byte[e];
                  System.arraycopy(outBuff, 0, finalOut, 0, e);
                  // System.err.println("Having to resize array from " +
                  // outBuff.length + " to " + e );
                  return finalOut;
              } else {
                  // System.err.println("No need to resize array.");
                  return outBuff;
              }
  
          } // end else: don't compress
  
      } // end encodeBytesToBytes
  
      /* ******** D E C O D I N G M E T H O D S ******** */
  
      /**
       * Decodes four bytes from array <var>source</var> and writes the resulting
       * bytes (up to three of them) to <var>destination</var>. The source and
       * destination arrays can be manipulated anywhere along their length by
       * specifying <var>srcOffset</var> and <var>destOffset</var>. This method
       * does not check to make sure your arrays are large enough to accomodate
       * <var>srcOffset</var> + 4 for the <var>source</var> array or
       * <var>destOffset</var> + 3 for the <var>destination</var> array. This
       * method returns the actual number of bytes that were converted from the
       * Base64 encoding.
       * <p>
       * This is the lowest level of the decoding methods with all possible
       * parameters.
       * </p>
       * 
       * 
       * @param source
       *            the array to convert
       * @param srcOffset
       *            the index where conversion begins
       * @param destination
       *            the array to hold the conversion
       * @param destOffset
       *            the index where output will be put
       * @param options
       *            alphabet type is pulled from this (standard, url-safe,
       *            ordered)
       * @return the number of decoded bytes converted
       * @throws NullPointerException
       *             if source or destination arrays are null
       * @throws IllegalArgumentException
       *             if srcOffset or destOffset are invalid or there is not enough
       *             room in the array.
       * @since 1.3
       */
      private static int decode4to3(byte[] source, int srcOffset, byte[] destination, int destOffset, int options) {
  
          // Lots of error checking and exception throwing
          if (source == null) {
              throw new NullPointerException("Source array was null.");
          } // end if
          if (destination == null) {
              throw new NullPointerException("Destination array was null.");
          } // end if
          if (srcOffset < 0 || srcOffset + 3 >= source.length) {
              throw new IllegalArgumentException(String.format(
                      "Source array with length %d cannot have offset of %d and still process four bytes.",
                      source.length, srcOffset));
          } // end if
          if (destOffset < 0 || destOffset + 2 >= destination.length) {
              throw new IllegalArgumentException(String.format(
                      "Destination array with length %d cannot have offset of %d and still store three bytes.",
                      destination.length, destOffset));
          } // end if
  
          byte[] DECODABET = getDecodabet(options);
  
          // Example: Dk==
          if (source[srcOffset + 2] == EQUALS_SIGN) {
              // Two ways to do the same thing. Don't know which way I like best.
              // int outBuff = ( ( DECODABET[ source[ srcOffset ] ] << 24 ) >>> 6
              // )
              // | ( ( DECODABET[ source[ srcOffset + 1] ] << 24 ) >>> 12 );
              int outBuff = ((DECODABET[source[srcOffset]] & 0xFF) << 18)
                      | ((DECODABET[source[srcOffset + 1]] & 0xFF) << 12);
  
              destination[destOffset] = (byte) (outBuff >>> 16);
              return 1;
          }
  
          // Example: DkL=
          else if (source[srcOffset + 3] == EQUALS_SIGN) {
              // Two ways to do the same thing. Don't know which way I like best.
              // int outBuff = ( ( DECODABET[ source[ srcOffset ] ] << 24 ) >>> 6
              // )
              // | ( ( DECODABET[ source[ srcOffset + 1 ] ] << 24 ) >>> 12 )
              // | ( ( DECODABET[ source[ srcOffset + 2 ] ] << 24 ) >>> 18 );
              int outBuff = ((DECODABET[source[srcOffset]] & 0xFF) << 18)
                      | ((DECODABET[source[srcOffset + 1]] & 0xFF) << 12)
                      | ((DECODABET[source[srcOffset + 2]] & 0xFF) << 6);
  
              destination[destOffset] = (byte) (outBuff >>> 16);
              destination[destOffset + 1] = (byte) (outBuff >>> 8);
              return 2;
          }
  
          // Example: DkLE
          else {
              // Two ways to do the same thing. Don't know which way I like best.
              // int outBuff = ( ( DECODABET[ source[ srcOffset ] ] << 24 ) >>> 6
              // )
              // | ( ( DECODABET[ source[ srcOffset + 1 ] ] << 24 ) >>> 12 )
              // | ( ( DECODABET[ source[ srcOffset + 2 ] ] << 24 ) >>> 18 )
              // | ( ( DECODABET[ source[ srcOffset + 3 ] ] << 24 ) >>> 24 );
              int outBuff = ((DECODABET[source[srcOffset]] & 0xFF) << 18)
                      | ((DECODABET[source[srcOffset + 1]] & 0xFF) << 12)
                      | ((DECODABET[source[srcOffset + 2]] & 0xFF) << 6) | ((DECODABET[source[srcOffset + 3]] & 0xFF));
  
              destination[destOffset] = (byte) (outBuff >> 16);
              destination[destOffset + 1] = (byte) (outBuff >> 8);
              destination[destOffset + 2] = (byte) (outBuff);
  
              return 3;
          }
      } // end decodeToBytes
  
      /**
       * Low-level access to decoding ASCII characters in the form of a byte
       * array. <strong>Ignores GUNZIP option, if it's set.</strong> This is not
       * generally a recommended method, although it is used internally as part of
       * the decoding process. Special case: if len = 0, an empty array is
       * returned. Still, if you need more speed and reduced memory footprint (and
       * aren't gzipping), consider this method.
       * 
       * @param source
       *            The Base64 encoded data
       * @return decoded data
       * @since 2.3.1
       */
      public static byte[] decode(byte[] source) throws java.io.IOException {
          byte[] decoded = null;
          // try {
          decoded = decode(source, 0, source.length, Base64.NO_OPTIONS);
          // } catch( java.io.IOException ex ) {
          // assert false :
          // "IOExceptions only come from GZipping, which is turned off: " +
          // ex.getMessage();
          // }
          return decoded;
      }
  
      /**
       * Low-level access to decoding ASCII characters in the form of a byte
       * array. <strong>Ignores GUNZIP option, if it's set.</strong> This is not
       * generally a recommended method, although it is used internally as part of
       * the decoding process. Special case: if len = 0, an empty array is
       * returned. Still, if you need more speed and reduced memory footprint (and
       * aren't gzipping), consider this method.
       * 
       * @param source
       *            The Base64 encoded data
       * @param off
       *            The offset of where to begin decoding
       * @param len
       *            The length of characters to decode
       * @param options
       *            Can specify options such as alphabet type to use
       * @return decoded data
       * @throws java.io.IOException
       *             If bogus characters exist in source data
       * @since 1.3
       */
      public static byte[] decode(byte[] source, int off, int len, int options) throws java.io.IOException {
  
          // Lots of error checking and exception throwing
          if (source == null) {
              throw new NullPointerException("Cannot decode null source array.");
          } // end if
          if (off < 0 || off + len > source.length) {
              throw new IllegalArgumentException(String.format(
                      "Source array with length %d cannot have offset of %d and process %d bytes.", source.length, off,
                      len));
          } // end if
  
          if (len == 0) {
              return new byte[0];
          } else if (len < 4) {
              throw new IllegalArgumentException(
                      "Base64-encoded string must have at least four characters, but length specified was " + len);
          } // end if
  
          byte[] DECODABET = getDecodabet(options);
  
          int len34 = len * 3 / 4; // Estimate on array size
          byte[] outBuff = new byte[len34]; // Upper limit on size of output
          int outBuffPosn = 0; // Keep track of where we're writing
  
          byte[] b4 = new byte[4]; // Four byte buffer from source, eliminating
                                   // white space
          int b4Posn = 0; // Keep track of four byte input buffer
          int i = 0; // Source array counter
          byte sbiDecode = 0; // Special value from DECODABET
  
          for (i = off; i < off + len; i++) { // Loop through source
  
              sbiDecode = DECODABET[source[i] & 0xFF];
  
              // White space, Equals sign, or legit Base64 character
              // Note the values such as -5 and -9 in the
              // DECODABETs at the top of the file.
              if (sbiDecode >= WHITE_SPACE_ENC) {
                  if (sbiDecode >= EQUALS_SIGN_ENC) {
                      b4[b4Posn++] = source[i]; // Save non-whitespace
                      if (b4Posn > 3) { // Time to decode?
                          outBuffPosn += decode4to3(b4, 0, outBuff, outBuffPosn, options);
                          b4Posn = 0;
  
                          // If that was the equals sign, break out of 'for' loop
                          if (source[i] == EQUALS_SIGN) {
                              break;
                          } // end if: equals sign
                      } // end if: quartet built
                  } // end if: equals sign or better
              } // end if: white space, equals sign or better
              else {
                  // There's a bad input character in the Base64 stream.
                  throw new java.io.IOException(String.format(
                          "Bad Base64 input character decimal %d in array position %d", ((int) source[i]) & 0xFF, i));
              } // end else:
          } // each input character
  
          byte[] out = new byte[outBuffPosn];
          System.arraycopy(outBuff, 0, out, 0, outBuffPosn);
          return out;
      } // end decode
  
      /**
       * Decodes data from Base64 notation, automatically detecting
       * gzip-compressed data and decompressing it.
       * 
       * @param s
       *            the string to decode
       * @return the decoded data
       * @throws java.io.IOException
       *             If there is a problem
       * @since 1.4
       */
      public static byte[] decode(String s) throws java.io.IOException {
          return decode(s, NO_OPTIONS);
      }
  
      /**
       * Decodes data from Base64 notation, automatically detecting
       * gzip-compressed data and decompressing it.
       * 
       * @param s
       *            the string to decode
       * @param options
       *            encode options such as URL_SAFE
       * @return the decoded data
       * @throws java.io.IOException
       *             if there is an error
       * @throws NullPointerException
       *             if <tt>s</tt> is null
       * @since 1.4
       */
      public static byte[] decode(String s, int options) throws java.io.IOException {
  
          if (s == null) {
              throw new NullPointerException("Input string was null.");
          } // end if
  
          byte[] bytes;
          try {
              bytes = s.getBytes(PREFERRED_ENCODING);
          } // end try
          catch (java.io.UnsupportedEncodingException uee) {
              bytes = IOUtils.toUTF8Bytes(s);
          } // end catch
            // </change>
  
          // Decode
          bytes = decode(bytes, 0, bytes.length, options);
  
          // Check to see if it's gzip-compressed
          // GZIP Magic Two-Byte Number: 0x8b1f (35615)
          boolean dontGunzip = (options & DONT_GUNZIP) != 0;
          if ((bytes != null) && (bytes.length >= 4) && (!dontGunzip)) {
  
              int head = ((int) bytes[0] & 0xff) | ((bytes[1] << 8) & 0xff00);
              if (java.util.zip.GZIPInputStream.GZIP_MAGIC == head) {
                  java.io.ByteArrayInputStream bais = null;
                  java.util.zip.GZIPInputStream gzis = null;
                  java.io.ByteArrayOutputStream baos = null;
                  byte[] buffer = new byte[2048];
                  int length = 0;
  
                  try {
                      baos = new java.io.ByteArrayOutputStream();
                      bais = new java.io.ByteArrayInputStream(bytes);
                      gzis = new java.util.zip.GZIPInputStream(bais, 64 * 1024);
  
                      while ((length = gzis.read(buffer)) >= 0) {
                          baos.write(buffer, 0, length);
                      } // end while: reading input
  
                      // No error? Get new bytes.
                      bytes = baos.toByteArray();
  
                  } // end try
                  catch (java.io.IOException e) {
                      LOG.error(e.getMessage(), e);
                      // Just return originally-decoded bytes
                  } // end catch
                  finally {
                      IOUtils.closeQuietly(baos);
                      IOUtils.closeQuietly(gzis);
                      IOUtils.closeQuietly(bais);
                  } // end finally
  
              } // end if: gzipped
          } // end if: bytes.length >= 2
  
          return bytes;
      } // end decode
  
      /**
       * Attempts to decode Base64 data and deserialize a Java Object within.
       * Returns <tt>null</tt> if there was an error.
       * 
       * @param encodedObject
       *            The Base64 data to decode
       * @return The decoded and deserialized object
       * @throws NullPointerException
       *             if encodedObject is null
       * @throws java.io.IOException
       *             if there is a general error
       * @throws ClassNotFoundException
       *             if the decoded object is of a class that cannot be found by
       *             the JVM
       * @since 1.5
       */
      public static Object decodeToObject(String encodedObject) throws java.io.IOException,
              java.lang.ClassNotFoundException {
          return decodeToObject(encodedObject, NO_OPTIONS, null);
      }
  
      /**
       * Attempts to decode Base64 data and deserialize a Java Object within.
       * Returns <tt>null</tt> if there was an error. If <tt>loader</tt> is not
       * null, it will be the class loader used when deserializing.
       * 
       * @param encodedObject
       *            The Base64 data to decode
       * @param options
       *            Various parameters related to decoding
       * @param loader
       *            Optional class loader to use in deserializing classes.
       * @return The decoded and deserialized object
       * @throws NullPointerException
       *             if encodedObject is null
       * @throws java.io.IOException
       *             if there is a general error
       * @throws ClassNotFoundException
       *             if the decoded object is of a class that cannot be found by
       *             the JVM
       * @since 2.3.4
       */
      public static Object decodeToObject(String encodedObject, int options, final ClassLoader loader)
              throws java.io.IOException, java.lang.ClassNotFoundException {
  
          // Decode and gunzip if necessary
          byte[] objBytes = decode(encodedObject, options);
  
          java.io.ByteArrayInputStream bais = null;
          java.io.ObjectInputStream ois = null;
          Object obj = null;
  
          try {
              bais = new java.io.ByteArrayInputStream(objBytes);
  
              // If no custom class loader is provided, use Java's builtin OIS.
              if (loader == null) {
                  ois = new java.io.ObjectInputStream(bais);
              } // end if: no loader provided
  
              // Else make a customized object input stream that uses
              // the provided class loader.
              else {
                  ois = new java.io.ObjectInputStream(bais) {
                      @Override
                      public Class<?> resolveClass(java.io.ObjectStreamClass streamClass) throws java.io.IOException,
                              ClassNotFoundException {
                          Class<?> c = Class.forName(streamClass.getName(), false, loader);
                          if (c == null) {
                              return super.resolveClass(streamClass);
                          } else {
                              return c; // Class loader knows of this class.
                          } // end else: not null
                      } // end resolveClass
                  }; // end ois
              } // end else: no custom class loader
  
              obj = ois.readObject();
          } // end try
          catch (java.io.IOException e) {
              throw e; // Catch and throw in order to execute finally{}
          } // end catch
          catch (java.lang.ClassNotFoundException e) {
              throw e; // Catch and throw in order to execute finally{}
          } // end catch
          finally {
              IOUtils.closeQuietly(bais);
              IOUtils.closeQuietly(ois);
          } // end finally
  
          return obj;
      } // end decodeObject
  
      /**
       * Convenience method for encoding data to a file.
       * 
       * <p>
       * As of v 2.3, if there is a error, the method will throw an
       * java.io.IOException. <b>This is new to v2.3!</b> In earlier versions, it
       * just returned false, but in retrospect that's a pretty poor way to handle
       * it.
       * </p>
       * 
       * @param dataToEncode
       *            byte array of data to encode in base64 form
       * @param filename
       *            Filename for saving encoded data
       * @throws java.io.IOException
       *             if there is an error
       * @throws NullPointerException
       *             if dataToEncode is null
       * @since 2.1
       */
      public static void encodeToFile(byte[] dataToEncode, String filename) throws java.io.IOException {
  
          if (dataToEncode == null) {
              throw new NullPointerException("Data to encode was null.");
          } // end iff
  
          Base64.OutputStream bos = null;
          try {
              bos = new Base64.OutputStream(new java.io.FileOutputStream(filename), Base64.ENCODE);
              bos.write(dataToEncode);
          } // end try
          catch (java.io.IOException e) {
              throw e; // Catch and throw to execute finally{} block
          } // end catch: java.io.IOException
          finally {
              IOUtils.closeQuietly(bos);
          } // end finally
  
      } // end encodeToFile
  
      /**
       * Convenience method for decoding data to a file.
       * 
       * <p>
       * As of v 2.3, if there is a error, the method will throw an
       * java.io.IOException. <b>This is new to v2.3!</b> In earlier versions, it
       * just returned false, but in retrospect that's a pretty poor way to handle
       * it.
       * </p>
       * 
       * @param dataToDecode
       *            Base64-encoded data as a string
       * @param filename
       *            Filename for saving decoded data
       * @throws java.io.IOException
       *             if there is an error
       * @since 2.1
       */
      public static void decodeToFile(String dataToDecode, String filename) throws java.io.IOException {
  
          Base64.OutputStream bos = null;
          try {
              bos = new Base64.OutputStream(new java.io.FileOutputStream(filename), Base64.DECODE);
              bos.write(dataToDecode.getBytes(PREFERRED_ENCODING));
          } // end try
          catch (java.io.IOException e) {
              throw e; // Catch and throw to execute finally{} block
          } // end catch: java.io.IOException
          finally {
              IOUtils.closeQuietly(bos);
          } // end finally
  
      } // end decodeToFile
  
      /**
       * Convenience method for reading a base64-encoded file and decoding it.
       * 
       * <p>
       * As of v 2.3, if there is a error, the method will throw an
       * java.io.IOException. <b>This is new to v2.3!</b> In earlier versions, it
       * just returned false, but in retrospect that's a pretty poor way to handle
       * it.
       * </p>
       * 
       * @param filename
       *            Filename for reading encoded data
       * @return decoded byte array
       * @throws java.io.IOException
       *             if there is an error
       * @since 2.1
       */
      public static byte[] decodeFromFile(String filename) throws java.io.IOException {
  
          byte[] decodedData = null;
          Base64.InputStream bis = null;
          try {
              // Set up some useful variables
              java.io.File file = new java.io.File(filename);
              byte[] buffer = null;
              int length = 0;
              int numBytes = 0;
  
              // Check for size of file
              if (file.length() > Integer.MAX_VALUE) {
                  throw new java.io.IOException("File is too big for this convenience method (" + file.length()
                          + " bytes).");
              } // end if: file too big for int index
              buffer = new byte[(int) file.length()];
  
              // Open a stream
              bis = new Base64.InputStream(new java.io.BufferedInputStream(new java.io.FileInputStream(file)),
                      Base64.DECODE);
  
              // Read until done
              while ((numBytes = bis.read(buffer, length, 4096)) >= 0) {
                  length += numBytes;
              } // end while
  
              // Save in a variable to return
              decodedData = new byte[length];
              System.arraycopy(buffer, 0, decodedData, 0, length);
  
          } // end try
          catch (java.io.IOException e) {
              throw e; // Catch and release to execute finally{}
          } // end catch: java.io.IOException
          finally {
              IOUtils.closeQuietly(bis);
          } // end finally
  
          return decodedData;
      } // end decodeFromFile
  
      /**
       * Convenience method for reading a binary file and base64-encoding it.
       * 
       * <p>
       * As of v 2.3, if there is a error, the method will throw an
       * java.io.IOException. <b>This is new to v2.3!</b> In earlier versions, it
       * just returned false, but in retrospect that's a pretty poor way to handle
       * it.
       * </p>
       * 
       * @param filename
       *            Filename for reading binary data
       * @return base64-encoded string
       * @throws java.io.IOException
       *             if there is an error
       * @since 2.1
       */
      public static String encodeFromFile(String filename) throws java.io.IOException {
  
          String encodedData = null;
          Base64.InputStream bis = null;
          try {
              // Set up some useful variables
              java.io.File file = new java.io.File(filename);
              byte[] buffer = new byte[Math.max((int) (file.length() * 1.4 + 1), 40)]; // Need
                                                                                       // max()
                                                                                       // for
                                                                                       // math
                                                                                       // on
                                                                                       // small
                                                                                       // files
                                                                                       // (v2.2.1);
                                                                                       // Need
                                                                                       // +1
                                                                                       // for
                                                                                       // a
                                                                                       // few
                                                                                       // corner
                                                                                       // cases
                                                                                       // (v2.3.5)
              int length = 0;
              int numBytes = 0;
  
              // Open a stream
              bis = new Base64.InputStream(new java.io.BufferedInputStream(new java.io.FileInputStream(file)),
                      Base64.ENCODE);
  
              // Read until done
              while ((numBytes = bis.read(buffer, length, 4096)) >= 0) {
                  length += numBytes;
              } // end while
  
              // Save in a variable to return
              encodedData = new String(buffer, 0, length, Base64.PREFERRED_ENCODING);
  
          } // end try
          catch (java.io.IOException e) {
              throw e; // Catch and release to execute finally{}
          } // end catch: java.io.IOException
          finally {
              IOUtils.closeQuietly(bis);
          } // end finally
  
          return encodedData;
      } // end encodeFromFile
  
      /**
       * Reads <tt>infile</tt> and encodes it to <tt>outfile</tt>.
       * 
       * @param infile
       *            Input file
       * @param outfile
       *            Output file
       * @throws java.io.IOException
       *             if there is an error
       * @since 2.2
       */
      public static void encodeFileToFile(String infile, String outfile) throws java.io.IOException {
  
          String encoded = Base64.encodeFromFile(infile);
          java.io.OutputStream out = null;
          try {
              out = new java.io.BufferedOutputStream(new java.io.FileOutputStream(outfile));
              out.write(encoded.getBytes("US-ASCII")); // Strict, 7-bit output.
          } // end try
          catch (java.io.IOException e) {
              throw e; // Catch and release to execute finally{}
          } // end catch
          finally {
              IOUtils.closeQuietly(out);
          } // end finally
      } // end encodeFileToFile
  
      /**
       * Reads <tt>infile</tt> and decodes it to <tt>outfile</tt>.
       * 
       * @param infile
       *            Input file
       * @param outfile
       *            Output file
       * @throws java.io.IOException
       *             if there is an error
       * @since 2.2
       */
      public static void decodeFileToFile(String infile, String outfile) throws java.io.IOException {
  
          byte[] decoded = Base64.decodeFromFile(infile);
          java.io.OutputStream out = null;
          try {
              out = new java.io.BufferedOutputStream(new java.io.FileOutputStream(outfile));
              out.write(decoded);
          } // end try
          catch (java.io.IOException e) {
              throw e; // Catch and release to execute finally{}
          } // end catch
          finally {
              IOUtils.closeQuietly(out);
          } // end finally
      } // end decodeFileToFile
  
      /* ******** I N N E R C L A S S I N P U T S T R E A M ******** */
  
      /**
       * A {@link Base64.InputStream} will read data from another
       * <tt>java.io.InputStream</tt>, given in the constructor, and encode/decode
       * to/from Base64 notation on the fly.
       * 
       * @see Base64
       * @since 1.3
       */
      public static class InputStream extends java.io.FilterInputStream {
  
          private boolean encode; // Encoding or decoding
          private int position; // Current position in the buffer
          private byte[] buffer; // Small buffer holding converted data
          private int bufferLength; // Length of buffer (3 or 4)
          private int numSigBytes; // Number of meaningful bytes in the buffer
          private int lineLength;
          private boolean breakLines; // Break lines at less than 80 characters
          private int options; // Record options used to create the stream.
          private byte[] decodabet; // Local copies to avoid extra method calls
  
          /**
           * Constructs a {@link Base64.InputStream} in DECODE mode.
           * 
           * @param in
           *            the <tt>java.io.InputStream</tt> from which to read data.
           * @since 1.3
           */
          public InputStream(java.io.InputStream in) {
              this(in, DECODE);
          } // end constructor
  
          /**
           * Constructs a {@link Base64.InputStream} in either ENCODE or DECODE
           * mode.
           * <p>
           * Valid options:
           * 
           * <pre>
           *   ENCODE or DECODE: Encode or Decode as data is read.
           *   DO_BREAK_LINES: break lines at 76 characters
           *   <i>(only meaningful when encoding)</i>
           * </pre>
           * <p>
           * Example: <code>new Base64.InputStream( in, Base64.DECODE )</code>
           * 
           * 
           * @param in
           *            the <tt>java.io.InputStream</tt> from which to read data.
           * @param options
           *            Specified options
           * @see Base64#ENCODE
           * @see Base64#DECODE
           * @see Base64#DO_BREAK_LINES
           * @since 2.0
           */
          public InputStream(java.io.InputStream in, int options) {
  
              super(in);
              this.options = options; // Record for later
              this.breakLines = (options & DO_BREAK_LINES) > 0;
              this.encode = (options & ENCODE) > 0;
              this.bufferLength = encode ? 4 : 3;
              this.buffer = new byte[bufferLength];
              this.position = -1;
              this.lineLength = 0;
              this.decodabet = getDecodabet(options);
          } // end constructor
  
          /**
           * Reads enough of the input stream to convert to/from Base64 and
           * returns the next byte.
           * 
           * @return next byte
           * @since 1.3
           */
          @Override
          public int read() throws java.io.IOException {
  
              // Do we need to get data?
              if (position < 0) {
                  if (encode) {
                      byte[] b3 = new byte[3];
                      int numBinaryBytes = 0;
                      for (int i = 0; i < 3; i++) {
                          int b = in.read();
  
                          // If end of stream, b is -1.
                          if (b >= 0) {
                              b3[i] = (byte) b;
                              numBinaryBytes++;
                          } else {
                              break; // out of for loop
                          } // end else: end of stream
  
                      } // end for: each needed input byte
  
                      if (numBinaryBytes > 0) {
                          encode3to4(b3, 0, numBinaryBytes, buffer, 0, options);
                          position = 0;
                          numSigBytes = 4;
                      } // end if: got data
                      else {
                          return -1; // Must be end of stream
                      } // end else
                  } // end if: encoding
  
                  // Else decoding
                  else {
                      byte[] b4 = new byte[4];
                      int i = 0;
                      for (i = 0; i < 4; i++) {
                          // Read four "meaningful" bytes:
                          int b = 0;
                          do {
                              b = in.read();
                          } while (b >= 0 && decodabet[b & 0x7f] <= WHITE_SPACE_ENC);
  
                          if (b < 0) {
                              break; // Reads a -1 if end of stream
                          } // end if: end of stream
  
                          b4[i] = (byte) b;
                      } // end for: each needed input byte
  
                      if (i == 4) {
                          numSigBytes = decode4to3(b4, 0, buffer, 0, options);
                          position = 0;
                      } // end if: got four characters
                      else if (i == 0) {
                          return -1;
                      } // end else if: also padded correctly
                      else {
                          // Must have broken out from above.
                          throw new java.io.IOException("Improperly padded Base64 input.");
                      } // end
  
                  } // end else: decode
              } // end else: get data
  
              // Got data?
              if (position >= 0) {
                  // End of relevant data?
                  if ( /* !encode && */position >= numSigBytes) {
                      return -1;
                  } // end if: got data
  
                  if (encode && breakLines && lineLength >= MAX_LINE_LENGTH) {
                      lineLength = 0;
                      return '\n';
                  } // end if
                  else {
                      lineLength++; // This isn't important when decoding
                                    // but throwing an extra "if" seems
                                    // just as wasteful.
  
                      int b = buffer[position++];
  
                      if (position >= bufferLength) {
                          position = -1;
                      } // end if: end
  
                      return b & 0xFF; // This is how you "cast" a byte that's
                                       // intended to be unsigned.
                  } // end else
              } // end if: position >= 0
  
              // Else error
              else {
                  throw new java.io.IOException("Error in Base64 code reading stream.");
              } // end else
          } // end read
  
          /**
           * Calls {@link #read()} repeatedly until the end of stream is reached
           * or <var>len</var> bytes are read. Returns number of bytes read into
           * array or -1 if end of stream is encountered.
           * 
           * @param dest
           *            array to hold values
           * @param off
           *            offset for array
           * @param len
           *            max number of bytes to read into array
           * @return bytes read into array or -1 if end of stream is encountered.
           * @since 1.3
           */
          @Override
          public int read(byte[] dest, int off, int len) throws java.io.IOException {
              int i;
              int b;
              for (i = 0; i < len; i++) {
                  b = read();
  
                  if (b >= 0) {
                      dest[off + i] = (byte) b;
                  } else if (i == 0) {
                      return -1;
                  } else {
                      break; // Out of 'for' loop
                  } // Out of 'for' loop
              } // end for: each byte read
              return i;
          } // end read
  
      } // end inner class InputStream
  
      /* ******** I N N E R C L A S S O U T P U T S T R E A M ******** */
  
      /**
       * A {@link Base64.OutputStream} will write data to another
       * <tt>java.io.OutputStream</tt>, given in the constructor, and
       * encode/decode to/from Base64 notation on the fly.
       * 
       * @see Base64
       * @since 1.3
       */
      public static class OutputStream extends java.io.FilterOutputStream {
  
          private boolean encode;
          private int position;
          private byte[] buffer;
          private int bufferLength;
          private int lineLength;
          private boolean breakLines;
          private byte[] b4; // Scratch used in a few places
          private boolean suspendEncoding;
          private int options; // Record for later
          private byte[] decodabet; // Local copies to avoid extra method calls
  
          /**
           * Constructs a {@link Base64.OutputStream} in ENCODE mode.
           * 
           * @param out
           *            the <tt>java.io.OutputStream</tt> to which data will be
           *            written.
           * @since 1.3
           */
          public OutputStream(java.io.OutputStream out) {
              this(out, ENCODE);
          } // end constructor
  
          /**
           * Constructs a {@link Base64.OutputStream} in either ENCODE or DECODE
           * mode.
           * <p>
           * Valid options:
           * 
           * <pre>
           *   ENCODE or DECODE: Encode or Decode as data is read.
           *   DO_BREAK_LINES: don't break lines at 76 characters
           *   <i>(only meaningful when encoding)</i>
           * </pre>
           * <p>
           * Example: <code>new Base64.OutputStream( out, Base64.ENCODE )</code>
           * 
           * @param out
           *            the <tt>java.io.OutputStream</tt> to which data will be
           *            written.
           * @param options
           *            Specified options.
           * @see Base64#ENCODE
           * @see Base64#DECODE
           * @see Base64#DO_BREAK_LINES
           * @since 1.3
           */
          public OutputStream(java.io.OutputStream out, int options) {
              super(out);
              this.breakLines = (options & DO_BREAK_LINES) != 0;
              this.encode = (options & ENCODE) != 0;
              this.bufferLength = encode ? 3 : 4;
              this.buffer = new byte[bufferLength];
              this.position = 0;
              this.lineLength = 0;
              this.suspendEncoding = false;
              this.b4 = new byte[4];
              this.options = options;
              this.decodabet = getDecodabet(options);
          } // end constructor
  
          /**
           * Writes the byte to the output stream after converting to/from Base64
           * notation. When encoding, bytes are buffered three at a time before
           * the output stream actually gets a write() call. When decoding, bytes
           * are buffered four at a time.
           * 
           * @param theByte
           *            the byte to write
           * @since 1.3
           */
          @Override
          public void write(int theByte) throws java.io.IOException {
              // Encoding suspended?
              if (suspendEncoding) {
                  this.out.write(theByte);
                  return;
              } // end if: supsended
  
              // Encode?
              if (encode) {
                  buffer[position++] = (byte) theByte;
                  if (position >= bufferLength) { // Enough to encode.
  
                      this.out.write(encode3to4(b4, buffer, bufferLength, options));
  
                      lineLength += 4;
                      if (breakLines && lineLength >= MAX_LINE_LENGTH) {
                          this.out.write(NEW_LINE);
                          lineLength = 0;
                      } // end if: end of line
  
                      position = 0;
                  } // end if: enough to output
              } // end if: encoding
  
              // Else, Decoding
              else {
                  // Meaningful Base64 character?
                  if (decodabet[theByte & 0x7f] > WHITE_SPACE_ENC) {
                      buffer[position++] = (byte) theByte;
                      if (position >= bufferLength) { // Enough to output.
  
                          int len = Base64.decode4to3(buffer, 0, b4, 0, options);
                          out.write(b4, 0, len);
                          position = 0;
                      } // end if: enough to output
                  } // end if: meaningful base64 character
                  else if (decodabet[theByte & 0x7f] != WHITE_SPACE_ENC) {
                      throw new java.io.IOException("Invalid character in Base64 data.");
                  } // end else: not white space either
              } // end else: decoding
          } // end write
  
          /**
           * Calls {@link #write(int)} repeatedly until <var>len</var> bytes are
           * written.
           * 
           * @param theBytes
           *            array from which to read bytes
           * @param off
           *            offset for array
           * @param len
           *            max number of bytes to read into array
           * @since 1.3
           */
          @Override
          public void write(byte[] theBytes, int off, int len) throws java.io.IOException {
              // Encoding suspended?
              if (suspendEncoding) {
                  this.out.write(theBytes, off, len);
                  return;
              } // end if: supsended
  
              for (int i = 0; i < len; i++) {
                  write(theBytes[off + i]);
              } // end for: each byte written
  
          } // end write
  
          /**
           * Method added by PHIL. [Thanks, PHIL. -Rob] This pads the buffer
           * without closing the stream.
           * 
           * @throws java.io.IOException
           *             if there's an error.
           */
          public void flushBase64() throws java.io.IOException {
              if (position > 0) {
                  if (encode) {
                      out.write(encode3to4(b4, buffer, position, options));
                      position = 0;
                  } // end if: encoding
                  else {
                      throw new java.io.IOException("Base64 input not properly padded.");
                  } // end else: decoding
              } // end if: buffer partially full
  
          } // end flush
  
          /**
           * Flushes and closes (I think, in the superclass) the stream.
           * 
           * @since 1.3
           */
          @Override
          public void close() throws java.io.IOException {
              // 1. Ensure that pending characters are written
              flushBase64();
  
              // 2. Actually close the stream
              // Base class both flushes and closes.
              super.close();
  
              buffer = null;
              out = null;
          } // end close
  
          /**
           * Suspends encoding of the stream. May be helpful if you need to embed
           * a piece of base64-encoded data in a stream.
           * 
           * @throws java.io.IOException
           *             if there's an error flushing
           * @since 1.5.1
           */
          public void suspendEncoding() throws java.io.IOException {
              flushBase64();
              this.suspendEncoding = true;
          } // end suspendEncoding
  
          /**
           * Resumes encoding of the stream. May be helpful if you need to embed a
           * piece of base64-encoded data in a stream.
           * 
           * @since 1.5.1
           */
          public void resumeEncoding() {
              this.suspendEncoding = false;
          } // end resumeEncoding
  
      } // end inner class OutputStream
  
  } // end class Base64
  