path: root/protocols/bundles/org.jivesoftware.smack/src/org/jivesoftware/smackx/filetransfer/Base64.java

package org.jivesoftware.smackx.filetransfer;

/**
 * Encodes and decodes to and from Base64 notation. <p/> <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/> <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
 */
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
	 *      &lt;i&gt;Note: Technically, this makes your encoding non-compliant.&lt;/i&gt;
	 * </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
	 *      &lt;i&gt;Note: Technically, this makes your encoding non-compliant.&lt;/i&gt;
	 * </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
	 *      &lt;i&gt;Note: Technically, this makes your encoding non-compliant.&lt;/i&gt;
	 * </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 {
				bis.close();
			} catch (Exception e) {
			}
		} // 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)
		 *      &lt;i&gt;Note: Technically, this makes your encoding non-compliant.&lt;/i&gt;
		 * </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)
		 *      &lt;i&gt;Note: Technically, this makes your encoding non-compliant.&lt;/i&gt;
		 * </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

} // end class Base64