com.messagebird.Base64 Maven / Gradle / Ivy
package com.messagebird;
/**
* Cutted version of iharder's base64 implementation
* @todo replace with actual library on next major bump
*
* Encodes and decodes to and from Base64 notation.
* Homepage: http://iharder.net/base64.
*
*
* 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 http://iharder.net/base64
* periodically to check for updates or to contribute improvements.
*
*
* @author Robert Harder
* @author [email protected]
* @version 2.3.7
*/
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 that gzipped data should not be automatically gunzipped. */
public final static int DONT_GUNZIP = 4;
/**
* Encode using Base64-like encoding that is URL- and Filename-safe as described
* in Section 4 of RFC3548:
* http://www.faqs.org/rfcs/rfc3548.html.
* It is important to note that data encoded this way is not 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:
* http://www.faqs.org/qa/rfcc-1940.html.
*/
public final static int ORDERED = 32;
/* ******** P R I V A T E F I E L D S ******** */
/** The equals sign (=) as a byte. */
private final static byte EQUALS_SIGN = (byte)'=';
/** Preferred encoding. */
private final static String PREFERRED_ENCODING = "US-ASCII";
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 ******** */
/**
* 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,-9 // Decimal 123 - 127
,-9,-9,-9,-9,-9,-9,-9,-9,-9,-9,-9,-9, // Decimal 128 - 139
-9,-9,-9,-9,-9,-9,-9,-9,-9,-9,-9,-9,-9, // Decimal 140 - 152
-9,-9,-9,-9,-9,-9,-9,-9,-9,-9,-9,-9,-9, // Decimal 153 - 165
-9,-9,-9,-9,-9,-9,-9,-9,-9,-9,-9,-9,-9, // Decimal 166 - 178
-9,-9,-9,-9,-9,-9,-9,-9,-9,-9,-9,-9,-9, // Decimal 179 - 191
-9,-9,-9,-9,-9,-9,-9,-9,-9,-9,-9,-9,-9, // Decimal 192 - 204
-9,-9,-9,-9,-9,-9,-9,-9,-9,-9,-9,-9,-9, // Decimal 205 - 217
-9,-9,-9,-9,-9,-9,-9,-9,-9,-9,-9,-9,-9, // Decimal 218 - 230
-9,-9,-9,-9,-9,-9,-9,-9,-9,-9,-9,-9,-9, // Decimal 231 - 243
-9,-9,-9,-9,-9,-9,-9,-9,-9,-9,-9,-9 // Decimal 244 - 255
};
/* ******** U R L S A F E B A S E 6 4 A L P H A B E T ******** */
/**
* Used in 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,-9 // Decimal 123 - 127
,-9,-9,-9,-9,-9,-9,-9,-9,-9,-9,-9,-9, // Decimal 128 - 139
-9,-9,-9,-9,-9,-9,-9,-9,-9,-9,-9,-9,-9, // Decimal 140 - 152
-9,-9,-9,-9,-9,-9,-9,-9,-9,-9,-9,-9,-9, // Decimal 153 - 165
-9,-9,-9,-9,-9,-9,-9,-9,-9,-9,-9,-9,-9, // Decimal 166 - 178
-9,-9,-9,-9,-9,-9,-9,-9,-9,-9,-9,-9,-9, // Decimal 179 - 191
-9,-9,-9,-9,-9,-9,-9,-9,-9,-9,-9,-9,-9, // Decimal 192 - 204
-9,-9,-9,-9,-9,-9,-9,-9,-9,-9,-9,-9,-9, // Decimal 205 - 217
-9,-9,-9,-9,-9,-9,-9,-9,-9,-9,-9,-9,-9, // Decimal 218 - 230
-9,-9,-9,-9,-9,-9,-9,-9,-9,-9,-9,-9,-9, // Decimal 231 - 243
-9,-9,-9,-9,-9,-9,-9,-9,-9,-9,-9,-9 // Decimal 244 - 255
};
/* ******** O R D E R E D B A S E 6 4 A L P H A B E T ******** */
/**
* 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,-9 // Decimal 123 - 127
,-9,-9,-9,-9,-9,-9,-9,-9,-9,-9,-9,-9,-9, // Decimal 128 - 139
-9,-9,-9,-9,-9,-9,-9,-9,-9,-9,-9,-9,-9, // Decimal 140 - 152
-9,-9,-9,-9,-9,-9,-9,-9,-9,-9,-9,-9,-9, // Decimal 153 - 165
-9,-9,-9,-9,-9,-9,-9,-9,-9,-9,-9,-9,-9, // Decimal 166 - 178
-9,-9,-9,-9,-9,-9,-9,-9,-9,-9,-9,-9,-9, // Decimal 179 - 191
-9,-9,-9,-9,-9,-9,-9,-9,-9,-9,-9,-9,-9, // Decimal 192 - 204
-9,-9,-9,-9,-9,-9,-9,-9,-9,-9,-9,-9,-9, // Decimal 205 - 217
-9,-9,-9,-9,-9,-9,-9,-9,-9,-9,-9,-9,-9, // Decimal 218 - 230
-9,-9,-9,-9,-9,-9,-9,-9,-9,-9,-9,-9,-9, // Decimal 231 - 243
-9,-9,-9,-9,-9,-9,-9,-9,-9,-9,-9,-9 // Decimal 244 - 255
};
/* ******** D E T E R M I N E W H I C H A L H A B E T ******** */
/**
* Returns one of the _SOMETHING_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(){}
/* ******** D E C O D I N G M E T H O D S ******** */
/**
* Decodes four bytes from array source
* and writes the resulting bytes (up to three of them)
* to destination.
* The source and destination arrays can be manipulated
* anywhere along their length by specifying
* srcOffset and destOffset.
* This method does not check to make sure your arrays
* are large enough to accomodate srcOffset + 4 for
* the source array or destOffset + 3 for
* the destination array.
* This method returns the actual number of bytes that
* were converted from the Base64 encoding.
* This is the lowest level of the decoding methods with
* all possible parameters.
*
*
* @param source the array to convert
* @param srcOffset the index where conversion begins
* @param destination the array to hold the conversion
* @param destOffset the index where output will be put
* @param options alphabet type is pulled from this (standard, url-safe, ordered)
* @return the number of decoded bytes converted
* @throws NullPointerException if source or destination arrays are null
* @throws IllegalArgumentException if srcOffset or destOffset are invalid
* or there is not enough room in the array.
* @since 1.3
*/
private static int decode4to3(
byte[] source, int srcOffset,
byte[] destination, int destOffset, int options ) {
// Lots of error checking and exception throwing
if( source == null ){
throw new NullPointerException( "Source array was null." );
} // end if
if( destination == null ){
throw new NullPointerException( "Destination array was null." );
} // end if
if( srcOffset < 0 || srcOffset + 3 >= source.length ){
throw new IllegalArgumentException( String.format(
"Source array with length %d cannot have offset of %d and still process four bytes.", source.length, srcOffset ) );
} // end if
if( destOffset < 0 || destOffset +2 >= destination.length ){
throw new IllegalArgumentException( String.format(
"Destination array with length %d cannot have offset of %d and still store three bytes.", destination.length, destOffset ) );
} // end if
byte[] DECODABET = getDecodabet( options );
// Example: Dk==
if( source[ srcOffset + 2] == EQUALS_SIGN ) {
// Two ways to do the same thing. Don't know which way I like best.
//int outBuff = ( ( DECODABET[ source[ srcOffset ] ] << 24 ) >>> 6 )
// | ( ( DECODABET[ source[ srcOffset + 1] ] << 24 ) >>> 12 );
int outBuff = ( ( DECODABET[ source[ srcOffset ] ] & 0xFF ) << 18 )
| ( ( DECODABET[ source[ srcOffset + 1] ] & 0xFF ) << 12 );
destination[ destOffset ] = (byte)( outBuff >>> 16 );
return 1;
}
// Example: DkL=
else if( source[ srcOffset + 3 ] == EQUALS_SIGN ) {
// Two ways to do the same thing. Don't know which way I like best.
//int outBuff = ( ( DECODABET[ source[ srcOffset ] ] << 24 ) >>> 6 )
// | ( ( DECODABET[ source[ srcOffset + 1 ] ] << 24 ) >>> 12 )
// | ( ( DECODABET[ source[ srcOffset + 2 ] ] << 24 ) >>> 18 );
int outBuff = ( ( DECODABET[ source[ srcOffset ] ] & 0xFF ) << 18 )
| ( ( DECODABET[ source[ srcOffset + 1 ] ] & 0xFF ) << 12 )
| ( ( DECODABET[ source[ srcOffset + 2 ] ] & 0xFF ) << 6 );
destination[ destOffset ] = (byte)( outBuff >>> 16 );
destination[ destOffset + 1 ] = (byte)( outBuff >>> 8 );
return 2;
}
// Example: DkLE
else {
// Two ways to do the same thing. Don't know which way I like best.
//int outBuff = ( ( DECODABET[ source[ srcOffset ] ] << 24 ) >>> 6 )
// | ( ( DECODABET[ source[ srcOffset + 1 ] ] << 24 ) >>> 12 )
// | ( ( DECODABET[ source[ srcOffset + 2 ] ] << 24 ) >>> 18 )
// | ( ( DECODABET[ source[ srcOffset + 3 ] ] << 24 ) >>> 24 );
int outBuff = ( ( DECODABET[ source[ srcOffset ] ] & 0xFF ) << 18 )
| ( ( DECODABET[ source[ srcOffset + 1 ] ] & 0xFF ) << 12 )
| ( ( DECODABET[ source[ srcOffset + 2 ] ] & 0xFF ) << 6)
| ( ( DECODABET[ source[ srcOffset + 3 ] ] & 0xFF ) );
destination[ destOffset ] = (byte)( outBuff >> 16 );
destination[ destOffset + 1 ] = (byte)( outBuff >> 8 );
destination[ destOffset + 2 ] = (byte)( outBuff );
return 3;
}
} // end decodeToBytes
/**
* Low-level access to decoding ASCII characters in
* the form of a byte array. Ignores GUNZIP option, if
* it's set. This is not generally a recommended method,
* although it is used internally as part of the decoding process.
* Special case: if len = 0, an empty array is returned. Still,
* if you need more speed and reduced memory footprint (and aren't
* gzipping), consider this method.
*
* @param source The Base64 encoded data
* @param off The offset of where to begin decoding
* @param len The length of characters to decode
* @param options Can specify options such as alphabet type to use
* @return decoded data
* @throws java.io.IOException If bogus characters exist in source data
* @since 1.3
*/
public static byte[] decode( byte[] source, int off, int len, int options )
throws java.io.IOException {
// Lots of error checking and exception throwing
if( source == null ){
throw new NullPointerException( "Cannot decode null source array." );
} // end if
if( off < 0 || off + len > source.length ){
throw new IllegalArgumentException( String.format(
"Source array with length %d cannot have offset of %d and process %d bytes.", source.length, off, len ) );
} // end if
if( len == 0 ){
return new byte[0];
}else if( len < 4 ){
throw new IllegalArgumentException(
"Base64-encoded string must have at least four characters, but length specified was " + len );
} // end if
byte[] DECODABET = getDecodabet( options );
int len34 = len * 3 / 4; // Estimate on array size
byte[] outBuff = new byte[ len34 ]; // Upper limit on size of output
int outBuffPosn = 0; // Keep track of where we're writing
byte[] b4 = new byte[4]; // Four byte buffer from source, eliminating white space
int b4Posn = 0; // Keep track of four byte input buffer
int i = 0; // Source array counter
byte sbiDecode = 0; // Special value from DECODABET
for( i = off; i < off+len; i++ ) { // Loop through source
sbiDecode = DECODABET[ source[i]&0xFF ];
// White space, Equals sign, or legit Base64 character
// Note the values such as -5 and -9 in the
// DECODABETs at the top of the file.
if( sbiDecode >= WHITE_SPACE_ENC ) {
if( sbiDecode >= EQUALS_SIGN_ENC ) {
b4[ b4Posn++ ] = source[i]; // Save non-whitespace
if( b4Posn > 3 ) { // Time to decode?
outBuffPosn += decode4to3( b4, 0, outBuff, outBuffPosn, options );
b4Posn = 0;
// If that was the equals sign, break out of 'for' loop
if( source[i] == EQUALS_SIGN ) {
break;
} // end if: equals sign
} // end if: quartet built
} // end if: equals sign or better
} // end if: white space, equals sign or better
else {
// There's a bad input character in the Base64 stream.
throw new java.io.IOException( String.format(
"Bad Base64 input character decimal %d in array position %d", ((int)source[i])&0xFF, i ) );
} // end else:
} // each input character
byte[] out = new byte[ outBuffPosn ];
System.arraycopy( outBuff, 0, out, 0, outBuffPosn );
return out;
} // end decode
/**
* Decodes data from Base64 notation, automatically
* detecting gzip-compressed data and decompressing it.
*
* @param s the string to decode
* @return the decoded data
* @throws java.io.IOException If there is a problem
* @since 1.4
*/
public static byte[] decode( String s ) throws java.io.IOException {
return decode( s, NO_OPTIONS );
}
/**
* Decodes data from Base64 notation, automatically
* detecting gzip-compressed data and decompressing it.
*
* @param s the string to decode
* @param options encode options such as URL_SAFE
* @return the decoded data
* @throws java.io.IOException if there is an error
* @throws NullPointerException if s is null
* @since 1.4
*/
public static byte[] decode( String s, int options ) throws java.io.IOException {
if( s == null ){
throw new NullPointerException( "Input string was null." );
} // end if
byte[] bytes;
try {
bytes = s.getBytes( PREFERRED_ENCODING );
} // end try
catch( java.io.UnsupportedEncodingException uee ) {
bytes = s.getBytes();
} // end catch
//
// Decode
bytes = decode( bytes, 0, bytes.length, options );
// Check to see if it's gzip-compressed
// GZIP Magic Two-Byte Number: 0x8b1f (35615)
boolean dontGunzip = (options & DONT_GUNZIP) != 0;
if( (bytes != null) && (bytes.length >= 4) && (!dontGunzip) ) {
int head = ((int)bytes[0] & 0xff) | ((bytes[1] << 8) & 0xff00);
if( java.util.zip.GZIPInputStream.GZIP_MAGIC == head ) {
java.io.ByteArrayInputStream bais = null;
java.util.zip.GZIPInputStream gzis = null;
java.io.ByteArrayOutputStream baos = null;
byte[] buffer = new byte[2048];
int length = 0;
try {
baos = new java.io.ByteArrayOutputStream();
bais = new java.io.ByteArrayInputStream( bytes );
gzis = new java.util.zip.GZIPInputStream( bais );
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 ) {
e.printStackTrace();
// 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
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