package de.uni_passau.fim.pkjab.util;
import java.io.FilterInputStream;
import java.io.FilterOutputStream;
/**
* <p>
* Encodes and decodes to and from Base64 notation.
* </p>
* <p>
* Homepage: <a href="http://iharder.net/base64">http://iharder.net/base64</a>.
* </p>
*
* <p>
* The <tt>options</tt> parameter, which appears in a few places, is used to
* pass several pieces of information to the encoder. In the "higher level"
* methods such as encodeBytes( bytes, options ) the options parameter can be
* used to indicate such things as first gzipping the bytes before encoding
* them, not inserting linefeeds (though that breaks strict Base64
* compatibility), and encoding using the URL-safe and Ordered dialects.
* </p>
*
* <p>
* The constants defined in Base64 can be OR-ed together to combine options, so
* you might make a call like this:
* </p>
*
* <code>String encoded = Base64.encodeBytes( mybytes, Base64.GZIP | Base64.DONT_BREAK_LINES );</code>
*
* <p>
* to compress the data before encoding it and then making the output have no
* newline characters.
* </p>
*
*
* <p>
* Change Log:
* </p>
* <ul>
* <li>v2.2.2 - Fixed encodeFileToFile and decodeFileToFile to use the
* Base64.InputStream class to encode and decode on the fly which uses less
* memory than encoding/decoding an entire file into memory before writing.</li>
* <li>v2.2.1 - Fixed bug using URL_SAFE and ORDERED encodings. Fixed bug when
* using very small files (~< 40 bytes).</li>
* <li>v2.2 - Added some helper methods for encoding/decoding directly from one
* file to the next. Also added a main() method to support command line
* encoding/decoding from one file to the next. Also added these Base64
* dialects:
* <ol>
* <li>The default is RFC3548 format.</li>
* <li>Calling Base64.setFormat(Base64.BASE64_FORMAT.URLSAFE_FORMAT) generates
* URL and file name friendly format as described in Section 4 of RFC3548.
* http://www.faqs.org/rfcs/rfc3548.html</li>
* <li>Calling Base64.setFormat(Base64.BASE64_FORMAT.ORDERED_FORMAT) generates
* URL and file name friendly format that preserves lexical ordering as
* described in http://www.faqs.org/qa/rfcc-1940.html</li>
* </ol>
* Special thanks to Jim Kellerman at <a
* href="http://www.powerset.com/">http://www.powerset.com/</a> for
* contributing the new Base64 dialects. </li>
*
* <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 2.2.2
*/
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;
/**
* Encode using Base64-like encoding that is URL- and Filename-safe as
* described in Section 4 of RFC3548: <a
* href="http://www.faqs.org/rfcs/rfc3548.html">http://www.faqs.org/rfcs/rfc3548.html</a>.
* It is important to note that data encoded this way is <em>not</em>
* officially valid Base64, or at the very least should not be called Base64
* without also specifying that is was encoded using the URL- and
* Filename-safe dialect.
*/
public final static int URL_SAFE = 16;
/**
* Encode using the special "ordered" dialect of Base64 described here: <a
* href="http://www.faqs.org/qa/rfcc-1940.html">http://www.faqs.org/qa/rfcc-1940.html</a>.
*/
public final static int ORDERED = 32;
/* ******** 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";
// 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
/* ******** S T A N D A R D B A S E 6 4 A L P H A B E T ******** */
/** The 64 valid Base64 values. */
// private final static byte[] ALPHABET;
/*
* Host platform me be something funny like EBCDIC, so we hardcode these
* values.
*/
private final static byte[] _STANDARD_ALPHABET = { (byte) 'A', (byte) 'B',
(byte) 'C', (byte) 'D', (byte) 'E', (byte) 'F', (byte) 'G',
(byte) 'H', (byte) 'I', (byte) 'J', (byte) 'K', (byte) 'L',
(byte) 'M', (byte) 'N', (byte) 'O', (byte) 'P', (byte) 'Q',
(byte) 'R', (byte) 'S', (byte) 'T', (byte) 'U', (byte) 'V',
(byte) 'W', (byte) 'X', (byte) 'Y', (byte) 'Z', (byte) 'a',
(byte) 'b', (byte) 'c', (byte) 'd', (byte) 'e', (byte) 'f',
(byte) 'g', (byte) 'h', (byte) 'i', (byte) 'j', (byte) 'k',
(byte) 'l', (byte) 'm', (byte) 'n', (byte) 'o', (byte) 'p',
(byte) 'q', (byte) 'r', (byte) 's', (byte) 't', (byte) 'u',
(byte) 'v', (byte) 'w', (byte) 'x', (byte) 'y', (byte) 'z',
(byte) '0', (byte) '1', (byte) '2', (byte) '3', (byte) '4',
(byte) '5', (byte) '6', (byte) '7', (byte) '8', (byte) '9',
(byte) '+', (byte) '/' };
/**
* Translates a Base64 value to either its 6-bit reconstruction value or a
* negative number indicating some other meaning.
*/
private final static byte[] _STANDARD_DECODABET = { -9, -9, -9, -9, -9, -9,
-9, -9, -9, // Decimal 0 - 8
-5, -5, // Whitespace: Tab and Linefeed
-9, -9, // Decimal 11 - 12
-5, // Whitespace: Carriage Return
-9, -9, -9, -9, -9, -9, -9, -9, -9, -9, -9, -9, -9, // Decimal 14 -
// 26
-9, -9, -9, -9, -9, // Decimal 27 - 31
-5, // Whitespace: Space
-9, -9, -9, -9, -9, -9, -9, -9, -9, -9, // Decimal 33 - 42
62, // Plus sign at decimal 43
-9, -9, -9, // Decimal 44 - 46
63, // Slash at decimal 47
52, 53, 54, 55, 56, 57, 58, 59, 60, 61, // Numbers zero through nine
-9, -9, -9, // Decimal 58 - 60
-1, // Equals sign at decimal 61
-9, -9, -9, // Decimal 62 - 64
0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, // Letters 'A'
// through 'N'
14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, // Letters 'O'
// through 'Z'
-9, -9, -9, -9, -9, -9, // Decimal 91 - 96
26, 27, 28, 29, 30, 31, 32, 33, 34, 35, 36, 37, 38, // Letters 'a'
// through 'm'
39, 40, 41, 42, 43, 44, 45, 46, 47, 48, 49, 50, 51, // Letters 'n'
// through 'z'
-9, -9, -9, -9 // 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
*/
};
/* ******** U R L S A F E B A S E 6 4 A L P H A B E T ******** */
/**
* Used in the URL- and Filename-safe dialect described in Section 4 of
* RFC3548: <a
* href="http://www.faqs.org/rfcs/rfc3548.html">http://www.faqs.org/rfcs/rfc3548.html</a>.
* Notice that the last two bytes become "hyphen" and "underscore" instead
* of "plus" and "slash."
*/
private final static byte[] _URL_SAFE_ALPHABET = { (byte) 'A', (byte) 'B',
(byte) 'C', (byte) 'D', (byte) 'E', (byte) 'F', (byte) 'G',
(byte) 'H', (byte) 'I', (byte) 'J', (byte) 'K', (byte) 'L',
(byte) 'M', (byte) 'N', (byte) 'O', (byte) 'P', (byte) 'Q',
(byte) 'R', (byte) 'S', (byte) 'T', (byte) 'U', (byte) 'V',
(byte) 'W', (byte) 'X', (byte) 'Y', (byte) 'Z', (byte) 'a',
(byte) 'b', (byte) 'c', (byte) 'd', (byte) 'e', (byte) 'f',
(byte) 'g', (byte) 'h', (byte) 'i', (byte) 'j', (byte) 'k',
(byte) 'l', (byte) 'm', (byte) 'n', (byte) 'o', (byte) 'p',
(byte) 'q', (byte) 'r', (byte) 's', (byte) 't', (byte) 'u',
(byte) 'v', (byte) 'w', (byte) 'x', (byte) 'y', (byte) 'z',
(byte) '0', (byte) '1', (byte) '2', (byte) '3', (byte) '4',
(byte) '5', (byte) '6', (byte) '7', (byte) '8', (byte) '9',
(byte) '-', (byte) '_' };
/**
* Used in decoding URL- and Filename-safe dialects of Base64.
*/
private final static byte[] _URL_SAFE_DECODABET = { -9, -9, -9, -9, -9, -9,
-9, -9, -9, // Decimal 0 - 8
-5, -5, // Whitespace: Tab and Linefeed
-9, -9, // Decimal 11 - 12
-5, // Whitespace: Carriage Return
-9, -9, -9, -9, -9, -9, -9, -9, -9, -9, -9, -9, -9, // Decimal 14 -
// 26
-9, -9, -9, -9, -9, // Decimal 27 - 31
-5, // Whitespace: Space
-9, -9, -9, -9, -9, -9, -9, -9, -9, -9, // Decimal 33 - 42
-9, // Plus sign at decimal 43
-9, // Decimal 44
62, // Minus sign at decimal 45
-9, // Decimal 46
-9, // Slash at decimal 47
52, 53, 54, 55, 56, 57, 58, 59, 60, 61, // Numbers zero through nine
-9, -9, -9, // Decimal 58 - 60
-1, // Equals sign at decimal 61
-9, -9, -9, // Decimal 62 - 64
0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, // Letters 'A'
// through 'N'
14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, // Letters 'O'
// through 'Z'
-9, -9, -9, -9, // Decimal 91 - 94
63, // Underscore at decimal 95
-9, // Decimal 96
26, 27, 28, 29, 30, 31, 32, 33, 34, 35, 36, 37, 38, // Letters 'a'
// through 'm'
39, 40, 41, 42, 43, 44, 45, 46, 47, 48, 49, 50, 51, // Letters 'n'
// through 'z'
-9, -9, -9, -9 // 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
*/
};
/* ******** O R D E R E D B A S E 6 4 A L P H A B E T ******** */
/**
* I don't get the point of this technique, but it is described here: <a
* href="http://www.faqs.org/qa/rfcc-1940.html">http://www.faqs.org/qa/rfcc-1940.html</a>.
*/
private final static byte[] _ORDERED_ALPHABET = { (byte) '-', (byte) '0',
(byte) '1', (byte) '2', (byte) '3', (byte) '4', (byte) '5',
(byte) '6', (byte) '7', (byte) '8', (byte) '9', (byte) 'A',
(byte) 'B', (byte) 'C', (byte) 'D', (byte) 'E', (byte) 'F',
(byte) 'G', (byte) 'H', (byte) 'I', (byte) 'J', (byte) 'K',
(byte) 'L', (byte) 'M', (byte) 'N', (byte) 'O', (byte) 'P',
(byte) 'Q', (byte) 'R', (byte) 'S', (byte) 'T', (byte) 'U',
(byte) 'V', (byte) 'W', (byte) 'X', (byte) 'Y', (byte) 'Z',
(byte) '_', (byte) 'a', (byte) 'b', (byte) 'c', (byte) 'd',
(byte) 'e', (byte) 'f', (byte) 'g', (byte) 'h', (byte) 'i',
(byte) 'j', (byte) 'k', (byte) 'l', (byte) 'm', (byte) 'n',
(byte) 'o', (byte) 'p', (byte) 'q', (byte) 'r', (byte) 's',
(byte) 't', (byte) 'u', (byte) 'v', (byte) 'w', (byte) 'x',
(byte) 'y', (byte) 'z' };
/**
* Used in decoding the "ordered" dialect of Base64.
*/
private final static byte[] _ORDERED_DECODABET = { -9, -9, -9, -9, -9, -9,
-9, -9, -9, // Decimal 0 - 8
-5, -5, // Whitespace: Tab and Linefeed
-9, -9, // Decimal 11 - 12
-5, // Whitespace: Carriage Return
-9, -9, -9, -9, -9, -9, -9, -9, -9, -9, -9, -9, -9, // Decimal 14 -
// 26
-9, -9, -9, -9, -9, // Decimal 27 - 31
-5, // Whitespace: Space
-9, -9, -9, -9, -9, -9, -9, -9, -9, -9, // Decimal 33 - 42
-9, // Plus sign at decimal 43
-9, // Decimal 44
0, // Minus sign at decimal 45
-9, // Decimal 46
-9, // Slash at decimal 47
1, 2, 3, 4, 5, 6, 7, 8, 9, 10, // Numbers zero through nine
-9, -9, -9, // Decimal 58 - 60
-1, // Equals sign at decimal 61
-9, -9, -9, // Decimal 62 - 64
11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, // Letters 'A'
// through 'M'
24, 25, 26, 27, 28, 29, 30, 31, 32, 33, 34, 35, 36, // Letters 'N'
// through 'Z'
-9, -9, -9, -9, // Decimal 91 - 94
37, // Underscore at decimal 95
-9, // Decimal 96
38, 39, 40, 41, 42, 43, 44, 45, 46, 47, 48, 49, 50, // Letters 'a'
// through 'm'
51, 52, 53, 54, 55, 56, 57, 58, 59, 60, 61, 62, 63, // Letters 'n'
// through 'z'
-9, -9, -9, -9 // 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
*/
};
/* ******** D E T E R M I N E W H I C H A L H A B E T ******** */
/**
* Returns one of the _SOMETHING_ALPHABET byte arrays depending on the
* options specified. It's possible, though silly, to specify ORDERED and
* URLSAFE in which case one of them will be picked, though there is no
* guarantee as to which one will be picked.
*/
private final static byte[] getAlphabet(int options) {
if ((options & URL_SAFE) == URL_SAFE)
return _URL_SAFE_ALPHABET;
else if ((options & ORDERED) == ORDERED)
return _ORDERED_ALPHABET;
else
return _STANDARD_ALPHABET;
} // end getAlphabet
/**
* Returns one of the _SOMETHING_DECODABET byte arrays depending on the
* options specified. It's possible, though silly, to specify ORDERED and
* URL_SAFE in which case one of them will be picked, though there is no
* guarantee as to which one will be picked.
*/
private final static byte[] getDecodabet(int options) {
if ((options & URL_SAFE) == URL_SAFE)
return _URL_SAFE_DECODABET;
else if ((options & ORDERED) == ORDERED)
return _ORDERED_DECODABET;
else
return _STANDARD_DECODABET;
} // end getAlphabet
/** Defeats instantiation. */
private Base64() {
}
/* ******** E N C O D I N G M E T H O D S ******** */
/**
* Encodes up to the first three bytes of array <var>threeBytes</var> and
* returns a four-byte array in Base64 notation. The actual number of
* significant bytes in your array is given by <var>numSigBytes</var>. The
* array <var>threeBytes</var> needs only be as big as <var>numSigBytes</var>.
* Code can reuse a byte array by passing a four-byte array as <var>b4</var>.
*
* @param b4
* A reusable byte array to reduce array instantiation
* @param threeBytes
* the array to convert
* @param numSigBytes
* the number of significant bytes in your array
* @return four byte array in Base64 notation.
* @since 1.5.1
*/
private static byte[] encode3to4(byte[] b4, byte[] threeBytes,
int numSigBytes, int options) {
encode3to4(threeBytes, 0, numSigBytes, b4, 0, options);
return b4;
} // end encode3to4
/**
* <p>
* Encodes up to three bytes of the array <var>source</var> and writes the
* resulting four Base64 bytes to <var>destination</var>. The source and
* destination arrays can be manipulated anywhere along their length by
* specifying <var>srcOffset</var> and <var>destOffset</var>. This method
* does not check to make sure your arrays are large enough to accomodate
* <var>srcOffset</var> + 3 for the <var>source</var> array or
* <var>destOffset</var> + 4 for the <var>destination</var> array. The
* actual number of significant bytes in your array is given by
* <var>numSigBytes</var>.
* </p>
* <p>
* This is the lowest level of the encoding methods with all possible
* parameters.
* </p>
*
* @param source
* the array to convert
* @param srcOffset
* the index where conversion begins
* @param numSigBytes
* the number of significant bytes in your array
* @param destination
* the array to hold the conversion
* @param destOffset
* the index where output will be put
* @return the <var>destination</var> array
* @since 1.3
*/
private static byte[] encode3to4(byte[] source, int srcOffset,
int numSigBytes, byte[] destination, int destOffset, int options) {
byte[] ALPHABET = getAlphabet(options);
// 1 2 3
// 01234567890123456789012345678901 Bit position
// --------000000001111111122222222 Array position from threeBytes
// --------| || || || | Six bit groups to index ALPHABET
// >>18 >>12 >> 6 >> 0 Right shift necessary
// 0x3f 0x3f 0x3f Additional AND
// Create buffer with zero-padding if there are only one or two
// significant bytes passed in the array.
// We have to shift left 24 in order to flush out the 1's that appear
// when Java treats a value as negative that is cast from a byte to an
// int.
int inBuff = (numSigBytes > 0 ? ((source[srcOffset] << 24) >>> 8) : 0)
| (numSigBytes > 1 ? ((source[srcOffset + 1] << 24) >>> 16) : 0)
| (numSigBytes > 2 ? ((source[srcOffset + 2] << 24) >>> 24) : 0);
switch (numSigBytes) {
case 3:
destination[destOffset] = ALPHABET[(inBuff >>> 18)];
destination[destOffset + 1] = ALPHABET[(inBuff >>> 12) & 0x3f];
destination[destOffset + 2] = ALPHABET[(inBuff >>> 6) & 0x3f];
destination[destOffset + 3] = ALPHABET[(inBuff) & 0x3f];
return destination;
case 2:
destination[destOffset] = ALPHABET[(inBuff >>> 18)];
destination[destOffset + 1] = ALPHABET[(inBuff >>> 12) & 0x3f];
destination[destOffset + 2] = ALPHABET[(inBuff >>> 6) & 0x3f];
destination[destOffset + 3] = EQUALS_SIGN;
return destination;
case 1:
destination[destOffset] = ALPHABET[(inBuff >>> 18)];
destination[destOffset + 1] = ALPHABET[(inBuff >>> 12) & 0x3f];
destination[destOffset + 2] = EQUALS_SIGN;
destination[destOffset + 3] = EQUALS_SIGN;
return destination;
default:
return destination;
} // end switch
} // end encode3to4
/**
* 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
* @param options
* alphabet type is pulled from this (standard, url-safe,
* ordered)
* @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) {
// deleted
return null;
} // 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, options);
lineLength += 4;
if (breakLines && lineLength == MAX_LINE_LENGTH) {
outBuff[e + 4] = NEW_LINE;
e++;
lineLength = 0;
} // end if: end of line
} // en dfor: each piece of array
if (d < len) {
encode3to4(source, d + off, len - d, outBuff, e, options);
e += 4;
} // end if: some padding needed
// 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.
* <p>
* This is the lowest level of the decoding methods with all possible
* parameters.
* </p>
*
*
* @param source
* the array to convert
* @param srcOffset
* the index where conversion begins
* @param destination
* the array to hold the conversion
* @param destOffset
* the index where output will be put
* @param options
* alphabet type is pulled from this (standard, url-safe,
* ordered)
* @return the number of decoded bytes converted
* @since 1.3
*/
private static int decode4to3(byte[] source, int srcOffset,
byte[] destination, int destOffset, int options) {
byte[] DECODABET = getDecodabet(options);
// Example: Dk==
if (source[srcOffset + 2] == EQUALS_SIGN) {
// Two ways to do the same thing. Don't know which way I like best.
// int outBuff = ( ( DECODABET[ source[ srcOffset ] ] << 24 ) >>> 6
// )
// | ( ( DECODABET[ source[ srcOffset + 1] ] << 24 ) >>> 12 );
int outBuff = ((DECODABET[source[srcOffset]] & 0xFF) << 18)
| ((DECODABET[source[srcOffset + 1]] & 0xFF) << 12);
destination[destOffset] = (byte) (outBuff >>> 16);
return 1;
}
// Example: DkL=
else if (source[srcOffset + 3] == EQUALS_SIGN) {
// Two ways to do the same thing. Don't know which way I like best.
// int outBuff = ( ( DECODABET[ source[ srcOffset ] ] << 24 ) >>> 6
// )
// | ( ( DECODABET[ source[ srcOffset + 1 ] ] << 24 ) >>> 12 )
// | ( ( DECODABET[ source[ srcOffset + 2 ] ] << 24 ) >>> 18 );
int outBuff = ((DECODABET[source[srcOffset]] & 0xFF) << 18)
| ((DECODABET[source[srcOffset + 1]] & 0xFF) << 12)
| ((DECODABET[source[srcOffset + 2]] & 0xFF) << 6);
destination[destOffset] = (byte) (outBuff >>> 16);
destination[destOffset + 1] = (byte) (outBuff >>> 8);
return 2;
}
// Example: DkLE
else {
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;
} // end 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 options) {
byte[] DECODABET = getDecodabet(options);
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,
options);
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) {
return decode(s, NO_OPTIONS);
}
/**
* Decodes data from Base64 notation, automatically detecting
* gzip-compressed data and decompressing it.
*
* @param s
* the string to decode
* @param options
* encode options such as URL_SAFE
* @return the decoded data
* @since 1.4
*/
public static byte[] decode(String s, int options) {
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, options);
// 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
} // end class Base64