/*
// $Id: //open/dev/farrago/src/org/eigenbase/util/RhBase64.java#7 $
// Package org.eigenbase is a class library of data management components.
// Copyright (C) 2006-2009 The Eigenbase Project
// Copyright (C) 2006-2009 SQLstream, Inc.
// Copyright (C) 2006-2009 LucidEra, Inc.
//
// This program is free software; you can redistribute it and/or modify it
// under the terms of the GNU General Public License as published by the Free
// Software Foundation; either version 2 of the License, or (at your option)
// any later version approved by The Eigenbase Project.
//
// This program is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
// GNU General Public License for more details.
//
// You should have received a copy of the GNU General Public License
// along with this program; if not, write to the Free Software
// Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
*/
package org.eigenbase.util;

/**
 * Encodes and decodes to and from Base64 notation.
 *
 * <p>Change Log:</p>
 *
 * <ul>
 * <li>v2.1 - Cleaned up javadoc comments and unused variables and methods.
 * Added some convenience methods for reading and writing to and from
 * files.</li>
 * <li>v2.0.2 - Now specifies UTF-8 encoding in places where the code fails on
 * systems with other encodings (like EBCDIC).</li>
 * <li>v2.0.1 - Fixed an error when decoding a single byte, that is, when the
 * encoded data was a single byte.</li>
 * <li>v2.0 - I got rid of methods that used booleans to set options. Now
 * everything is more consolidated and cleaner. The code now detects when data
 * that's being decoded is gzip-compressed and will decompress it automatically.
 * Generally things are cleaner. You'll probably have to change some method
 * calls that you were making to support the new options format (<tt>int</tt>s
 * that you "OR" together).</li>
 * <li>v1.5.1 - Fixed bug when decompressing and decoding to a byte[] using <tt>
 * decode( String s, boolean gzipCompressed )</tt>. Added the ability to
 * "suspend" encoding in the Output Stream so you can turn on and off the
 * encoding if you need to embed base64 data in an otherwise "normal" stream
 * (like an XML file).</li>
 * <li>v1.5 - Output stream pases on flush() command but doesn't do anything
 * itself. This helps when using GZIP streams. Added the ability to
 * GZip-compress objects before encoding them.</li>
 * <li>v1.4 - Added helper methods to read/write files.</li>
 * <li>v1.3.6 - Fixed OutputStream.flush() so that 'position' is reset.</li>
 * <li>v1.3.5 - Added flag to turn on and off line breaks. Fixed bug in input
 * stream where last buffer being read, if not completely full, was not
 * returned.</li>
 * <li>v1.3.4 - Fixed when "improperly padded stream" error was thrown at the
 * wrong time.</li>
 * <li>v1.3.3 - Fixed I/O streams which were totally messed up.</li>
 * </ul>
 *
 * <p>I am placing this code in the Public Domain. Do with it as you will. This
 * software comes with no guarantees or warranties but with plenty of
 * well-wishing instead! Please visit <a href="http://iharder.net/base64">
 * http://iharder.net/base64</a> periodically to check for updates or to
 * contribute improvements.</p>
 *
 * @author Robert Harder
 * @author rob@iharder.net
 * @version 2.1
 */
public class RhBase64
{
    /* ********  P U B L I C   F I E L D S  ******** */

    //~ Static fields/initializers ---------------------------------------------

    /**
     * No options specified. Value is zero.
     */
    public final static int NO_OPTIONS = 0;

    /**
     * Specify encoding.
     */
    public final static int ENCODE = 1;

    /**
     * Specify decoding.
     */
    public final static int DECODE = 0;

    /**
     * Specify that data should be gzip-compressed.
     */
    public final static int GZIP = 2;

    /**
     * Don't break lines when encoding (violates strict Base64 specification)
     */
    public final static int DONT_BREAK_LINES = 8;

    /* ********  P R I V A T E   F I E L D S  ******** */

    /**
     * Maximum line length (76) of Base64 output.
     */
    private final static int MAX_LINE_LENGTH = 76;

    /**
     * The equals sign (=) as a byte.
     */
    private final static byte EQUALS_SIGN = (byte) '=';

    /**
     * The new line character (\n) as a byte.
     */
    private final static byte NEW_LINE = (byte) '\n';

    /**
     * Preferred encoding.
     */
    private final static String PREFERRED_ENCODING = "UTF-8";

    /**
     * The 64 valid Base64 values.
     */
    private final static byte [] ALPHABET;
    private final static byte [] _NATIVE_ALPHABET = /* May be something funny
                                                     like EBCDIC */
    {
        (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) '/'
    };

    /**
     * Determine which ALPHABET to use.
     */
    static {
        byte [] __bytes;
        try {
            __bytes =
                "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/"
                .getBytes(PREFERRED_ENCODING);
        } catch (java.io.UnsupportedEncodingException use) {
            __bytes = _NATIVE_ALPHABET; // Fall back to native encoding
        }
        ALPHABET = __bytes;
    }

    /**
     * Translates a Base64 value to either its 6-bit reconstruction value or a
     * negative number indicating some other meaning.
     */
    private final static byte [] 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 // Decimal 123 - 126

        /*,-9,-9,-9,-9,-9,-9,-9,-9,-9,-9,-9,-9,-9,     // Decimal 127 - 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
         */
    };

    // I think I end up not using the BAD_ENCODING indicator. private final
    // static byte BAD_ENCODING    = -9; // Indicates error in encoding
    private final static byte WHITE_SPACE_ENC = -5; // Indicates white space in
                                                    // encoding
    private final static byte EQUALS_SIGN_ENC = -1; // Indicates equals sign in
                                                    // encoding

    //~ Constructors -----------------------------------------------------------

    /**
     * Defeats instantiation.
     */
    private RhBase64()
    {
    }

    //~ Methods ----------------------------------------------------------------

    /* ********  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)
    {
        encode3to4(threeBytes, 0, numSigBytes, b4, 0);
        return b4;
    }

    /**
     * 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>.
     *
     * @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)
    {
        //           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;
        }
    }

    /**
     * Serializes an object and returns the Base64-encoded version of that
     * serialized object. If the object cannot be serialized or there is another
     * error, the method will return <tt>null</tt>. The object is not
     * GZip-compressed before being encoded.
     *
     * @param serializableObject The object to encode
     *
     * @return The Base64-encoded object
     *
     * @since 1.4
     */
    public static String encodeObject(java.io.Serializable serializableObject)
    {
        return encodeObject(serializableObject, NO_OPTIONS);
    }

    /**
     * Serializes an object and returns the Base64-encoded version of that
     * serialized object. If the object cannot be serialized or there is another
     * error, the method will return <tt>null</tt>.
     *
     * <p>Valid options:
     *
     * <pre>
     *   GZIP: gzip-compresses object before encoding it.
     *   DONT_BREAK_LINES: don't break lines at 76 characters
     *     <i>Note: Technically, this makes your encoding non-compliant.</i>
     * </pre>
     *
     * <p>Example: <code>encodeObject( myObj, RhBase64.GZIP )</code> or
     *
     * <p>Example: <code>encodeObject( myObj, RhBase64.GZIP |
     * RhBase64.DONT_BREAK_LINES )</code>
     *
     * @param serializableObject The object to encode
     * @param options Specified options
     *
     * @return The Base64-encoded object
     *
     * @see RhBase64#GZIP
     * @see RhBase64#DONT_BREAK_LINES
     * @since 2.0
     */
    public static String encodeObject(
        java.io.Serializable serializableObject,
        int options)
    {
        // Streams
        java.io.ByteArrayOutputStream baos = null;
        java.io.OutputStream b64os = null;
        java.io.ObjectOutputStream oos = null;
        java.util.zip.GZIPOutputStream gzos = null;

        // Isolate options
        int gzip = (options & GZIP);
        int dontBreakLines = (options & DONT_BREAK_LINES);

        try {
            // ObjectOutputStream -> (GZIP) -> Base64 -> ByteArrayOutputStream
            baos = new java.io.ByteArrayOutputStream();
            b64os = new RhBase64.OutputStream(baos, ENCODE | dontBreakLines);

            // GZip?
            if (gzip == GZIP) {
                gzos = new java.util.zip.GZIPOutputStream(b64os);
                oos = new java.io.ObjectOutputStream(gzos);
            } else {
                oos = new java.io.ObjectOutputStream(b64os);
            }

            oos.writeObject(serializableObject);
        } catch (java.io.IOException e) {
            e.printStackTrace();
            return null;
        } finally {
            try {
                oos.close();
            } catch (Exception e) {
            }
            try {
                gzos.close();
            } catch (Exception e) {
            }
            try {
                b64os.close();
            } catch (Exception e) {
            }
            try {
                baos.close();
            } catch (Exception e) {
            }
        }

        // Return value according to relevant encoding.
        try {
            return new String(
                baos.toByteArray(),
                PREFERRED_ENCODING);
        } catch (java.io.UnsupportedEncodingException uue) {
            return new String(baos.toByteArray());
        }
    }

    /**
     * Encodes a byte array into Base64 notation. Does not GZip-compress data.
     *
     * @param source The data to convert
     *
     * @since 1.4
     */
    public static String encodeBytes(byte [] source)
    {
        return encodeBytes(source, 0, source.length, NO_OPTIONS);
    }

    /**
     * Encodes a byte array into Base64 notation.
     *
     * <p>Valid options:
     *
     * <pre>
     *   GZIP: gzip-compresses object before encoding it.
     *   DONT_BREAK_LINES: don't break lines at 76 characters
     *     <i>Note: Technically, this makes your encoding non-compliant.</i>
     * </pre>
     *
     * <p>Example: <code>encodeBytes( myData, RhBase64.GZIP )</code> or
     *
     * <p>Example: <code>encodeBytes( myData, RhBase64.GZIP |
     * RhBase64.DONT_BREAK_LINES )</code>
     *
     * @param source The data to convert
     * @param options Specified options
     *
     * @see RhBase64#GZIP
     * @see RhBase64#DONT_BREAK_LINES
     * @since 2.0
     */
    public static String encodeBytes(byte [] source, int options)
    {
        return encodeBytes(source, 0, source.length, options);
    }

    /**
     * Encodes a byte array into Base64 notation. Does not GZip-compress data.
     *
     * @param source The data to convert
     * @param off Offset in array where conversion should begin
     * @param len Length of data to convert
     *
     * @since 1.4
     */
    public static String encodeBytes(byte [] source, int off, int len)
    {
        return encodeBytes(source, off, len, NO_OPTIONS);
    }

    /**
     * Encodes a byte array into Base64 notation.
     *
     * <p>Valid options:
     *
     * <pre>
     *   GZIP: gzip-compresses object before encoding it.
     *   DONT_BREAK_LINES: don't break lines at 76 characters
     *     <i>Note: Technically, this makes your encoding non-compliant.</i>
     * </pre>
     *
     * <p>Example: <code>encodeBytes( myData, RhBase64.GZIP )</code> or
     *
     * <p>Example: <code>encodeBytes( myData, RhBase64.GZIP |
     * RhBase64.DONT_BREAK_LINES )</code>
     *
     * @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
     *
     * @see RhBase64#GZIP
     * @see RhBase64#DONT_BREAK_LINES
     * @since 2.0
     */
    public static String encodeBytes(
        byte [] source,
        int off,
        int len,
        int options)
    {
        // Isolate options
        int dontBreakLines = (options & DONT_BREAK_LINES);
        int gzip = (options & GZIP);

        // Compress?
        if (gzip == GZIP) {
            java.io.ByteArrayOutputStream baos = null;
            java.util.zip.GZIPOutputStream gzos = null;
            RhBase64.OutputStream b64os = null;

            try {
                // GZip -> Base64 -> ByteArray
                baos = new java.io.ByteArrayOutputStream();
                b64os =
                    new RhBase64.OutputStream(baos, ENCODE | dontBreakLines);
                gzos = new java.util.zip.GZIPOutputStream(b64os);

                gzos.write(source, off, len);
                gzos.close();
            } catch (java.io.IOException e) {
                e.printStackTrace();
                return null;
            } finally {
                try {
                    gzos.close();
                } catch (Exception e) {
                }
                try {
                    b64os.close();
                } catch (Exception e) {
                }
                try {
                    baos.close();
                } catch (Exception e) {
                }
            }

            // Return value according to relevant encoding.
            try {
                return new String(
                    baos.toByteArray(),
                    PREFERRED_ENCODING);
            } catch (java.io.UnsupportedEncodingException uue) {
                return new String(baos.toByteArray());
            }
        } else {
            // Else, don't compress. Better not to use streams at all then.
            // Convert option to boolean in way that code likes it.
            boolean breakLines = dontBreakLines == 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
            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);

                lineLength += 4;
                if (breakLines && (lineLength == MAX_LINE_LENGTH)) {
                    outBuff[e + 4] = NEW_LINE;
                    e++;
                    lineLength = 0;
                }
            } // en dfor: each piece of array

            if (d < len) {
                encode3to4(source, d + off, len - d, outBuff, e);
                e += 4;
            }

            // Return value according to relevant encoding.
            try {
                return new String(outBuff, 0, e, PREFERRED_ENCODING);
            } catch (java.io.UnsupportedEncodingException uue) {
                return new String(outBuff, 0, e);
            }
        }
    }

    /* ********  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.
     *
     * @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
     *
     * @return the number of decoded bytes converted
     *
     * @since 1.3
     */
    private static int decode4to3(
        byte [] source,
        int srcOffset,
        byte [] destination,
        int destOffset)
    {
        // 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;
        } else if (source[srcOffset + 3] == EQUALS_SIGN) {
        // Example: DkL=
            // 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;
        } else {
            // Example: DkLE
            try {
                // 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;
            } catch (Exception e) {
                System.out.println(
                    "" + source[srcOffset] + ": "
                    + (DECODABET[source[srcOffset]]));
                System.out.println(
                    "" + source[srcOffset + 1] + ": "
                    + (DECODABET[source[srcOffset + 1]]));
                System.out.println(
                    "" + source[srcOffset + 2] + ": "
                    + (DECODABET[source[srcOffset + 2]]));
                System.out.println(
                    "" + source[srcOffset + 3] + ": "
                    + (DECODABET[source[srcOffset + 3]]));
                return -1;
            }
        }
    }

    /**
     * Very low-level access to decoding ASCII characters in the form of a byte
     * array. Does not support automatically gunzipping or any other "fancy"
     * features.
     *
     * @param source The Base64 encoded data
     * @param off The offset of where to begin decoding
     * @param len The length of characters to decode
     *
     * @return decoded data
     *
     * @since 1.3
     */
    public static byte [] decode(byte [] source, int off, int len)
    {
        int len34 = len * 3 / 4;
        byte [] outBuff = new byte[len34]; // Upper limit on size of output
        int outBuffPosn = 0;

        byte [] b4 = new byte[4];
        int b4Posn = 0;
        int i = 0;
        byte sbiCrop = 0;
        byte sbiDecode = 0;
        for (i = off; i < (off + len); i++) {
            sbiCrop = (byte) (source[i] & 0x7f); // Only the low seven bits
            sbiDecode = DECODABET[sbiCrop];

            if (sbiDecode >= WHITE_SPACE_ENC) {
                 // White space, Equals sign or better
                if (sbiDecode >= EQUALS_SIGN_ENC) {
                    b4[b4Posn++] = sbiCrop;
                    if (b4Posn > 3) {
                        outBuffPosn += decode4to3(b4, 0, outBuff, outBuffPosn);
                        b4Posn = 0;

                        // If that was the equals sign, break out of 'for' loop
                        if (sbiCrop == EQUALS_SIGN) {
                            break;
                        }
                    }
                }
            } else {
                System.err.println(
                    "Bad Base64 input character at " + i + ": " + source[i]
                    + "(decimal)");
                return null;
            }
        }

        byte [] out = new byte[outBuffPosn];
        System.arraycopy(outBuff, 0, out, 0, outBuffPosn);
        return out;
    }

    /**
     * Decodes data from Base64 notation, automatically detecting
     * gzip-compressed data and decompressing it.
     *
     * @param s the string to decode
     *
     * @return the decoded data
     *
     * @since 1.4
     */
    public static byte [] decode(String s)
    {
        byte [] bytes;
        try {
            bytes = s.getBytes(PREFERRED_ENCODING);
        } catch (java.io.UnsupportedEncodingException uee) {
            bytes = s.getBytes();
        }

        //</change>

        // Decode
        bytes = decode(bytes, 0, bytes.length);

        // Check to see if it's gzip-compressed
        // GZIP Magic Two-Byte Number: 0x8b1f (35615)
        if ((bytes != null) && (bytes.length >= 4)) {
            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);

                    while ((length = gzis.read(buffer)) >= 0) {
                        baos.write(buffer, 0, length);
                    }

                    // No error? Get new bytes.
                    bytes = baos.toByteArray();
                } catch (java.io.IOException e) {
                    // Just return originally-decoded bytes
                } finally {
                    try {
                        baos.close();
                    } catch (Exception e) {
                    }
                    try {
                        gzis.close();
                    } catch (Exception e) {
                    }
                    try {
                        bais.close();
                    } catch (Exception e) {
                    }
                }
            }
        }

        return bytes;
    }

    /**
     * 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
     *
     * @since 1.5
     */
    public static Object decodeToObject(String encodedObject)
    {
        // Decode and gunzip if necessary
        byte [] objBytes = decode(encodedObject);

        java.io.ByteArrayInputStream bais = null;
        java.io.ObjectInputStream ois = null;
        Object obj = null;

        try {
            bais = new java.io.ByteArrayInputStream(objBytes);
            ois = new java.io.ObjectInputStream(bais);

            obj = ois.readObject();
        } catch (java.io.IOException e) {
            e.printStackTrace();
            obj = null;
        } catch (java.lang.ClassNotFoundException e) {
            e.printStackTrace();
            obj = null;
        } finally {
            try {
                bais.close();
            } catch (Exception e) {
            }
            try {
                ois.close();
            } catch (Exception e) {
            }
        }

        return obj;
    }

    /**
     * Convenience method for encoding data to a file.
     *
     * @param dataToEncode byte array of data to encode in base64 form
     * @param filename Filename for saving encoded data
     *
     * @return <tt>true</tt> if successful, <tt>false</tt> otherwise
     *
     * @since 2.1
     */
    public static boolean encodeToFile(byte [] dataToEncode, String filename)
    {
        boolean success = false;
        RhBase64.OutputStream bos = null;
        try {
            bos =
                new RhBase64.OutputStream(
                    new java.io.FileOutputStream(filename),
                    RhBase64.ENCODE);
            bos.write(dataToEncode);
            success = true;
        } catch (java.io.IOException e) {
            success = false;
        } finally {
            try {
                bos.close();
            } catch (Exception e) {
            }
        }

        return success;
    }

    /**
     * Convenience method for decoding data to a file.
     *
     * @param dataToDecode Base64-encoded data as a string
     * @param filename Filename for saving decoded data
     *
     * @return <tt>true</tt> if successful, <tt>false</tt> otherwise
     *
     * @since 2.1
     */
    public static boolean decodeToFile(String dataToDecode, String filename)
    {
        boolean success = false;
        RhBase64.OutputStream bos = null;
        try {
            bos =
                new RhBase64.OutputStream(
                    new java.io.FileOutputStream(filename),
                    RhBase64.DECODE);
            bos.write(dataToDecode.getBytes(PREFERRED_ENCODING));
            success = true;
        } catch (java.io.IOException e) {
            success = false;
        } finally {
            try {
                bos.close();
            } catch (Exception e) {
            }
        }

        return success;
    }

    /**
     * Convenience method for reading a base64-encoded file and decoding it.
     *
     * @param filename Filename for reading encoded data
     *
     * @return decoded byte array or null if unsuccessful
     *
     * @since 2.1
     */
    public static byte [] decodeFromFile(String filename)
    {
        byte [] decodedData = null;
        RhBase64.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) {
                System.err.println(
                    "File is too big for this convenience method ("
                    + file.length() + " bytes).");
                return null;
            }
            buffer = new byte[(int) file.length()];

            // Open a stream
            bis =
                new RhBase64.InputStream(
                    new java.io.BufferedInputStream(
                        new java.io.FileInputStream(file)),
                    RhBase64.DECODE);

            // Read until done
            while ((numBytes = bis.read(buffer, length, 4096)) >= 0) {
                length += numBytes;
            }

            // Save in a variable to return
            decodedData = new byte[length];
            System.arraycopy(buffer, 0, decodedData, 0, length);
        } catch (java.io.IOException e) {
            System.err.println("Error decoding from file " + filename);
        } finally {
            try {
                bis.close();
            } catch (Exception e) {
            }
        }

        return decodedData;
    }

    /**
     * Convenience method for reading a binary file and base64-encoding it.
     *
     * @param filename Filename for reading binary data
     *
     * @return base64-encoded string or null if unsuccessful
     *
     * @since 2.1
     */
    public static String encodeFromFile(String filename)
    {
        String encodedData = null;
        RhBase64.InputStream bis = null;
        try {
            // Set up some useful variables
            java.io.File file = new java.io.File(filename);
            byte [] buffer = new byte[(int) (file.length() * 1.4)];
            int length = 0;
            int numBytes = 0;

            // Open a stream
            bis =
                new RhBase64.InputStream(
                    new java.io.BufferedInputStream(
                        new java.io.FileInputStream(file)),
                    RhBase64.ENCODE);

            // Read until done
            while ((numBytes = bis.read(buffer, length, 4096)) >= 0) {
                length += numBytes;
            }

            // Save in a variable to return
            encodedData =
                new String(buffer, 0, length, RhBase64.PREFERRED_ENCODING);
        } catch (java.io.IOException e) {
            System.err.println("Error encoding from file " + filename);
        } finally {
            try {
                bis.close();
            } catch (Exception e) {
            }
        }

        return encodedData;
    }

    //~ Inner Classes ----------------------------------------------------------

    /* ********  I N N E R   C L A S S   I N P U T S T R E A M  ******** */

    /**
     * A {@link RhBase64.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 RhBase64
     * @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

        /**
         * Constructs a {@link RhBase64.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);
        }

        /**
         * Constructs a {@link RhBase64.InputStream} in either ENCODE or DECODE
         * mode.
         *
         * <p>Valid options:
         *
         * <pre>
         *   ENCODE or DECODE: Encode or Decode as data is read.
         *   DONT_BREAK_LINES: don't break lines at 76 characters
         *     (only meaningful when encoding)
         *     <i>Note: Technically, this makes your encoding non-compliant.</i>
         * </pre>
         *
         * <p>Example: <code>new RhBase64.InputStream( in, RhBase64.DECODE
         * )</code>
         *
         * @param in the <tt>java.io.InputStream</tt> from which to read data.
         * @param options Specified options
         *
         * @see RhBase64#ENCODE
         * @see RhBase64#DECODE
         * @see RhBase64#DONT_BREAK_LINES
         * @since 2.0
         */
        public InputStream(java.io.InputStream in, int options)
        {
            super(in);
            this.breakLines = (options & DONT_BREAK_LINES) != DONT_BREAK_LINES;
            this.encode = (options & ENCODE) == ENCODE;
            this.bufferLength = encode ? 4 : 3;
            this.buffer = new byte[bufferLength];
            this.position = -1;
            this.lineLength = 0;
        }

        /**
         * Reads enough of the input stream to convert to/from Base64 and
         * returns the next byte.
         *
         * @return next byte
         *
         * @since 1.3
         */
        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++) {
                        try {
                            int b = in.read();

                            // If end of stream, b is -1.
                            if (b >= 0) {
                                b3[i] = (byte) b;
                                numBinaryBytes++;
                            }
                        } catch (java.io.IOException e) {
                            // Only a problem if we got no data at all.
                            if (i == 0) {
                                throw e;
                            }
                        }
                    }

                    if (numBinaryBytes > 0) {
                        encode3to4(b3, 0, numBinaryBytes, buffer, 0);
                        position = 0;
                        numSigBytes = 4;
                    } else {
                        return -1;
                    }
                } else {
                    // Else decoding
                    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
                        }

                        b4[i] = (byte) b;
                    }

                    if (i == 4) {
                        numSigBytes = decode4to3(b4, 0, buffer, 0);
                        position = 0;
                    } else if (i == 0) {
                        return -1;
                    } else {
                        // Must have broken out from above.
                        throw new java.io.IOException(
                            "Improperly padded Base64 input.");
                    }
                }
            }

            // Got data?
            if (position >= 0) {
                // End of relevant data?
                if (position >= numSigBytes) {
                    return -1;
                }

                if (encode && breakLines && (lineLength >= MAX_LINE_LENGTH)) {
                    lineLength = 0;
                    return '\n';
                } else {
                    // This isn't important when decoding
                    // but throwing an extra "if" seems
                    // just as wasteful.
                    lineLength++;

                    int b = buffer[position++];

                    if (position >= bufferLength) {
                        position = -1;
                    }

                    return b & 0xFF; // This is how you "cast" a byte that's
                                     // intended to be unsigned.
                }
            } else {
                // Else error
                // When JDK1.4 is more accepted, use an assertion here.
                throw new java.io.IOException(
                    "Error in Base64 code reading stream.");
            }
        }

        /**
         * 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
         */
        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 && i == 0 )
                //    return -1;

                if (b >= 0) {
                    dest[off + i] = (byte) b;
                } else if (i == 0) {
                    return -1;
                } else {
                    break; // Out of 'for' loop
                }
            }
            return i;
        }
    }

    /* ********  I N N E R   C L A S S   O U T P U T S T R E A M  ******** */

    /**
     * A {@link RhBase64.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 RhBase64
     * @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;

        /**
         * Constructs a {@link RhBase64.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);
        }

        /**
         * Constructs a {@link RhBase64.OutputStream} in either ENCODE or DECODE
         * mode.
         *
         * <p>Valid options:
         *
         * <pre>
         *   ENCODE or DECODE: Encode or Decode as data is read.
         *   DONT_BREAK_LINES: don't break lines at 76 characters
         *     (only meaningful when encoding)
         *     <i>Note: Technically, this makes your encoding non-compliant.</i>
         * </pre>
         *
         * <p>Example: <code>new RhBase64.OutputStream( out, RhBase64.ENCODE
         * )</code>
         *
         * @param out the <tt>java.io.OutputStream</tt> to which data will be
         * written.
         * @param options Specified options.
         *
         * @see RhBase64#ENCODE
         * @see RhBase64#DECODE
         * @see RhBase64#DONT_BREAK_LINES
         * @since 1.3
         */
        public OutputStream(java.io.OutputStream out, int options)
        {
            super(out);
            this.breakLines = (options & DONT_BREAK_LINES) != DONT_BREAK_LINES;
            this.encode = (options & ENCODE) == ENCODE;
            this.bufferLength = encode ? 3 : 4;
            this.buffer = new byte[bufferLength];
            this.position = 0;
            this.lineLength = 0;
            this.suspendEncoding = false;
            this.b4 = new byte[4];
        }

        /**
         * 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
         */
        public void write(int theByte)
            throws java.io.IOException
        {
            // Encoding suspended?
            if (suspendEncoding) {
                super.out.write(theByte);
                return;
            }

            // Encode?
            if (encode) {
                buffer[position++] = (byte) theByte;
                if (position >= bufferLength) {
                     // Enough to encode.
                    out.write(encode3to4(b4, buffer, bufferLength));

                    lineLength += 4;
                    if (breakLines && (lineLength >= MAX_LINE_LENGTH)) {
                        out.write(NEW_LINE);
                        lineLength = 0;
                    }

                    position = 0;
                }
            } else {
                // Else, Decoding
                // Meaningful Base64 character?
                if (DECODABET[theByte & 0x7f] > WHITE_SPACE_ENC) {
                    buffer[position++] = (byte) theByte;
                    if (position >= bufferLength) {
                         // Enough to output.
                        int len = RhBase64.decode4to3(buffer, 0, b4, 0);
                        out.write(b4, 0, len);

                        //out.write( RhBase64.decode4to3( buffer ) );
                        position = 0;
                    }
                } else if (DECODABET[theByte & 0x7f] != WHITE_SPACE_ENC) {
                    throw new java.io.IOException(
                        "Invalid character in Base64 data.");
                }
            }
        }

        /**
         * 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
         */
        public void write(byte [] theBytes, int off, int len)
            throws java.io.IOException
        {
            // Encoding suspended?
            if (suspendEncoding) {
                super.out.write(theBytes, off, len);
                return;
            }

            for (int i = 0; i < len; i++) {
                write(theBytes[off + i]);
            }
        }

        /**
         * Method added by PHIL. [Thanks, PHIL. -Rob] This pads the buffer
         * without closing the stream.
         */
        public void flushBase64()
            throws java.io.IOException
        {
            if (position > 0) {
                if (encode) {
                    out.write(encode3to4(b4, buffer, position));
                    position = 0;
                } else {
                    throw new java.io.IOException(
                        "Base64 input not properly padded.");
                }
            }
        }

        /**
         * Flushes and closes (I think, in the superclass) the stream.
         *
         * @since 1.3
         */
        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;
        }

        /**
         * Suspends encoding of the stream. May be helpful if you need to embed
         * a piece of base640-encoded data in a stream.
         *
         * @since 1.5.1
         */
        public void suspendEncoding()
            throws java.io.IOException
        {
            flushBase64();
            this.suspendEncoding = true;
        }

        /**
         * Resumes encoding of the stream. May be helpful if you need to embed a
         * piece of base640-encoded data in a stream.
         *
         * @since 1.5.1
         */
        public void resumeEncoding()
        {
            this.suspendEncoding = false;
        }
    }
}

// End RhBase64.java
