package ise.plugin.svn.library;

/**
 * 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 Base64 {

   /* ********  P U B L I C   F I E L D S  ******** */


   /** 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 );
      }   // end try
      catch ( java.io.UnsupportedEncodingException use ) {
         __bytes = _NATIVE_ALPHABET; // Fall back to native encoding
      }   // end catch

      ALPHABET = __bytes;
   }   // end static


   /**
    * 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


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


   /**
    * 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;
      }   // end switch
   }   // end encode3to4



   /**
    * 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 );
   }   // end encodeObject



   /**
    * 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, Base64.GZIP )</code> or
    * <p>
    * Example: <code>encodeObject( myObj, Base64.GZIP | Base64.DONT_BREAK_LINES )</code>
    *
    * @param serializableObject The object to encode
    * @param options Specified options
    * @return The Base64-encoded object
    * @see Base64#GZIP
    * @see Base64#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 Base64.OutputStream( baos, ENCODE | dontBreakLines );

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

         oos.writeObject( serializableObject );
      }   // end try
      catch ( java.io.IOException e ) {
         e.printStackTrace();
         return null;
      }   // end catch
      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 ) {}
      }   // end finally

      // Return value according to relevant encoding.

      try {
         return new String( baos.toByteArray(), PREFERRED_ENCODING );
      }   // end try
      catch ( java.io.UnsupportedEncodingException uue ) {
         return new String( baos.toByteArray() );
      }   // end catch

   }   // end encode



   /**
    * 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 );
   }   // end encodeBytes



   /**
    * 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, Base64.GZIP )</code> or
    * <p>
    * Example: <code>encodeBytes( myData, Base64.GZIP | Base64.DONT_BREAK_LINES )</code>
    *
    *
    * @param source The data to convert
    * @param options Specified options
    * @see Base64#GZIP
    * @see Base64#DONT_BREAK_LINES
    * @since 2.0
    */
   public static String encodeBytes( byte[] source, int options ) {
      return encodeBytes( source, 0, source.length, options );
   }   // end encodeBytes


   /**
    * 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 );
   }   // end encodeBytes



   /**
    * 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, Base64.GZIP )</code> or
    * <p>
    * Example: <code>encodeBytes( myData, Base64.GZIP | Base64.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 Base64#GZIP
    * @see Base64#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;
         Base64.OutputStream b64os = null;


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

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

         // Return value according to relevant encoding.

         try {
            return new String( baos.toByteArray(), PREFERRED_ENCODING );
         }   // end try
         catch ( java.io.UnsupportedEncodingException uue ) {
            return new String( baos.toByteArray() );
         }   // end catch
      }   // end if: compress

      // Else, don't compress. Better not to use streams at all then.

      else {
         // 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;
            }   // end if: end of line
         }   // en dfor: each piece of array


         if ( d < len ) {
            encode3to4( source, d + off, len - d, outBuff, e );
            e += 4;
         }   // end if: some padding needed


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

      }   // end else: don't compress

   }   // end encodeBytes





   /* ********  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;
      }

      // 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 {
         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;
         }   //e nd catch
      }
   }   // end decodeToBytes




   /**
    * 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;
               }   // end if: quartet built

            }   // end if: equals sign or better

         }   // end if: white space, equals sign or better

         else {
            System.err.println( "Bad Base64 input character at " + i + ": " + source[ i ] + "(decimal)" );
            return null;
         }   // 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
    * @since 1.4
    */
   public static byte[] decode( String s ) {
      byte[] bytes;
      try {
         bytes = s.getBytes( PREFERRED_ENCODING );
      }   // end try
      catch ( java.io.UnsupportedEncodingException uee ) {
         bytes = s.getBytes();
      }   // end catch
      //</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 );
               }   // end while: reading input

               // No error? Get new bytes.
               bytes = baos.toByteArray();

            }   // end try
            catch ( java.io.IOException e ) {
               // Just return originally-decoded bytes
            }   // end catch

            finally {
               try {
                  baos.close();
               }
               catch ( Exception e ) {}
               try {
                  gzis.close();
               }
               catch ( Exception e ) {}
               try {
                  bais.close();
               }
               catch ( Exception e ) {}
            }   // 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
    * @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();
      }   // end try
      catch ( java.io.IOException e ) {
         e.printStackTrace();
         obj = null;
      }   // end catch
      catch ( java.lang.ClassNotFoundException e ) {
         e.printStackTrace();
         obj = null;
      }   // end catch
      finally {
         try {
            bais.close();
         }
         catch ( Exception e ) {}
         try {
            ois.close();
         }
         catch ( Exception e ) {}
      }   // end finally


      return obj;
   }   // end decodeObject



   /**
    * 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;
      Base64.OutputStream bos = null;
      try {
         bos = new Base64.OutputStream(
                  new java.io.FileOutputStream( filename ), Base64.ENCODE );
         bos.write( dataToEncode );
         success = true;
      }   // end try
      catch ( java.io.IOException e ) {

         success = false;
      }   // end catch: IOException
      finally {
         try {
            bos.close();
         }
         catch ( Exception e ) {}
      }   // end finally


      return success;
   }   // end encodeToFile


   /**
    * 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;
      Base64.OutputStream bos = null;
      try {
         bos = new Base64.OutputStream(
                  new java.io.FileOutputStream( filename ), Base64.DECODE );
         bos.write( dataToDecode.getBytes( PREFERRED_ENCODING ) );
         success = true;
      }   // end try
      catch ( java.io.IOException e ) {
         success = false;
      }   // end catch: IOException
      finally {
         try {
            bos.close();
         }
         catch ( Exception e ) {}
      }   // end finally


      return success;
   }   // end decodeToFile




   /**
    * 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;
      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 ) {
            System.err.println( "File is too big for this convenience method (" + file.length() + " bytes)." );
            return null;
         }   // 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;

         // Save in a variable to return
         decodedData = new byte[ length ];
         System.arraycopy( buffer, 0, decodedData, 0, length );

      }   // end try
      catch ( java.io.IOException e ) {
         System.err.println( "Error decoding from file " + filename );
      }   // end catch: IOException
      finally {
         try {
             if ( bis != null ) {
                bis.close();
             }
         }
         catch ( Exception e ) {
             System.err.println( "Error closing stream." );
         }
      }   // end finally


      return decodedData;
   }   // end decodeFromFile



   /**
    * 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;
      Base64.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 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;

         // Save in a variable to return
         encodedData = new String( buffer, 0, length, Base64.PREFERRED_ENCODING );

      }   // end try
      catch ( java.io.IOException e ) {
         System.err.println( "Error encoding from file " + filename );
      }   // end catch: IOException
      finally {
         try {
            bis.close();
         }
         catch ( Exception e ) {}
      }   // end finally


      return encodedData;
   }   // end encodeFromFile




   /* ********  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


      /**
       * 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.
       *   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 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#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;
      }   // end constructor

      /**
       * 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++;
                     }   // end if: not end of stream

                  }   // end try: read

                  catch ( java.io.IOException e ) {
                     // Only a problem if we got no data at all.
                     if ( i == 0 )
                        throw e;

                  }   // end catch
               }   // end for: each needed input byte


               if ( numBinaryBytes > 0 ) {
                  encode3to4( b3, 0, numBinaryBytes, buffer, 0 );
                  position = 0;
                  numSigBytes = 4;
               }   // end if: got data
               else {
                  return -1;
               }   // 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

                  b4[ i ] = ( byte ) b;
               }   // end for: each needed input byte

               if ( i == 4 ) {
                  numSigBytes = decode4to3( b4, 0, buffer, 0 );
                  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;

            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;

               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 {
            // When JDK1.4 is more accepted, use an assertion here.
            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
       */
      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
         }   // 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;

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

         // 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;
               }   // 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 );
                  out.write( b4, 0, len );
                  //out.write( Base64.decode4to3( buffer ) );
                  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
       */
      public void write( byte[] theBytes, int off, int len ) throws java.io.IOException {
         // Encoding suspended?
         if ( suspendEncoding ) {
            super.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.
       */
      public void flushBase64() throws java.io.IOException {
         if ( position > 0 ) {
            if ( encode ) {
               out.write( encode3to4( b4, buffer, position ) );
               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
       */
      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
       * base640-encoded data in a stream.
       *
       * @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
       * base640-encoded data in a stream.
       *
       * @since 1.5.1
       */
      public void resumeEncoding() {
         this.suspendEncoding = false;
      }   // end resumeEncoding



   }   // end inner class OutputStream

   public static void main (String[] args) {
       String command = args[0];
       System.out.println(command);
       String to_change = args[1];
       System.out.println(to_change);
       String answer = null;
       if ("decode".equals(command)) {
            answer = new String(Base64.decode(to_change));
       }
       else if ("encode".equals(command)) {
            answer = Base64.encodeBytes(to_change.getBytes());
       }
       else {
            System.out.println("invalid command, 'decode' and 'encode' are valid commands");
            System.exit(1);
       }
       System.out.println(answer);
       System.exit(0);
   }

}   // end class Base64