001 /*
002 * Licensed to the Apache Software Foundation (ASF) under one or more
003 * contributor license agreements. See the NOTICE file distributed with
004 * this work for additional information regarding copyright ownership.
005 * The ASF licenses this file to You under the Apache License, Version 2.0
006 * (the "License"); you may not use this file except in compliance with
007 * the License. You may obtain a copy of the License at
008 *
009 * http://www.apache.org/licenses/LICENSE-2.0
010 *
011 * Unless required by applicable law or agreed to in writing, software
012 * distributed under the License is distributed on an "AS IS" BASIS,
013 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
014 * See the License for the specific language governing permissions and
015 * limitations under the License.
016 */
017
018 package org.apache.commons.net.util;
019
020 import java.io.UnsupportedEncodingException;
021 import java.math.BigInteger;
022
023
024
025 /**
026 * Provides Base64 encoding and decoding as defined by RFC 2045.
027 *
028 * <p>
029 * This class implements section <cite>6.8. Base64 Content-Transfer-Encoding</cite> from RFC 2045 <cite>Multipurpose
030 * Internet Mail Extensions (MIME) Part One: Format of Internet Message Bodies</cite> by Freed and Borenstein.
031 * </p>
032 * <p>
033 * The class can be parameterized in the following manner with various constructors:
034 * <ul>
035 * <li>URL-safe mode: Default off.</li>
036 * <li>Line length: Default 76. Line length that aren't multiples of 4 will still essentially end up being multiples of
037 * 4 in the encoded data.
038 * <li>Line separator: Default is CRLF ("\r\n")</li>
039 * </ul>
040 * </p>
041 * <p>
042 * Since this class operates directly on byte streams, and not character streams, it is hard-coded to only encode/decode
043 * character encodings which are compatible with the lower 127 ASCII chart (ISO-8859-1, Windows-1252, UTF-8, etc).
044 * </p>
045 *
046 * @see <a href="http://www.ietf.org/rfc/rfc2045.txt">RFC 2045</a>
047 * @author Apache Software Foundation
048 * @since 2.2
049 * @version $Id: Base64.java 1407341 2012-11-09 01:31:00Z ggregory $
050 */
051 public class Base64 {
052 private static final int DEFAULT_BUFFER_RESIZE_FACTOR = 2;
053
054 private static final int DEFAULT_BUFFER_SIZE = 8192;
055
056 /**
057 * Chunk size per RFC 2045 section 6.8.
058 *
059 * <p>
060 * The {@value} character limit does not count the trailing CRLF, but counts all other characters, including any
061 * equal signs.
062 * </p>
063 *
064 * @see <a href="http://www.ietf.org/rfc/rfc2045.txt">RFC 2045 section 6.8</a>
065 */
066 static final int CHUNK_SIZE = 76;
067
068 /**
069 * Chunk separator per RFC 2045 section 2.1.
070 *
071 * @see <a href="http://www.ietf.org/rfc/rfc2045.txt">RFC 2045 section 2.1</a>
072 */
073 private static final byte[] CHUNK_SEPARATOR = {'\r', '\n'};
074
075 private static final byte[] EMPTY_BYTE_ARRAY = new byte[0];
076
077 /**
078 * This array is a lookup table that translates 6-bit positive integer index values into their "Base64 Alphabet"
079 * equivalents as specified in Table 1 of RFC 2045.
080 *
081 * Thanks to "commons" project in ws.apache.org for this code.
082 * http://svn.apache.org/repos/asf/webservices/commons/trunk/modules/util/
083 */
084 private static final byte[] STANDARD_ENCODE_TABLE = {
085 'A', 'B', 'C', 'D', 'E', 'F', 'G', 'H', 'I', 'J', 'K', 'L', 'M',
086 'N', 'O', 'P', 'Q', 'R', 'S', 'T', 'U', 'V', 'W', 'X', 'Y', 'Z',
087 'a', 'b', 'c', 'd', 'e', 'f', 'g', 'h', 'i', 'j', 'k', 'l', 'm',
088 'n', 'o', 'p', 'q', 'r', 's', 't', 'u', 'v', 'w', 'x', 'y', 'z',
089 '0', '1', '2', '3', '4', '5', '6', '7', '8', '9', '+', '/'
090 };
091
092 /**
093 * This is a copy of the STANDARD_ENCODE_TABLE above, but with + and /
094 * changed to - and _ to make the encoded Base64 results more URL-SAFE.
095 * This table is only used when the Base64's mode is set to URL-SAFE.
096 */
097 private static final byte[] URL_SAFE_ENCODE_TABLE = {
098 'A', 'B', 'C', 'D', 'E', 'F', 'G', 'H', 'I', 'J', 'K', 'L', 'M',
099 'N', 'O', 'P', 'Q', 'R', 'S', 'T', 'U', 'V', 'W', 'X', 'Y', 'Z',
100 'a', 'b', 'c', 'd', 'e', 'f', 'g', 'h', 'i', 'j', 'k', 'l', 'm',
101 'n', 'o', 'p', 'q', 'r', 's', 't', 'u', 'v', 'w', 'x', 'y', 'z',
102 '0', '1', '2', '3', '4', '5', '6', '7', '8', '9', '-', '_'
103 };
104
105 /**
106 * Byte used to pad output.
107 */
108 private static final byte PAD = '=';
109
110 /**
111 * This array is a lookup table that translates Unicode characters drawn from the "Base64 Alphabet" (as specified in
112 * Table 1 of RFC 2045) into their 6-bit positive integer equivalents. Characters that are not in the Base64
113 * alphabet but fall within the bounds of the array are translated to -1.
114 *
115 * Note: '+' and '-' both decode to 62. '/' and '_' both decode to 63. This means decoder seamlessly handles both
116 * URL_SAFE and STANDARD base64. (The encoder, on the other hand, needs to know ahead of time what to emit).
117 *
118 * Thanks to "commons" project in ws.apache.org for this code.
119 * http://svn.apache.org/repos/asf/webservices/commons/trunk/modules/util/
120 */
121 private static final byte[] DECODE_TABLE = {
122 -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1,
123 -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1,
124 -1, -1, -1, -1, -1, -1, -1, -1, -1, 62, -1, 62, -1, 63, 52, 53, 54,
125 55, 56, 57, 58, 59, 60, 61, -1, -1, -1, -1, -1, -1, -1, 0, 1, 2, 3, 4,
126 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23,
127 24, 25, -1, -1, -1, -1, 63, -1, 26, 27, 28, 29, 30, 31, 32, 33, 34,
128 35, 36, 37, 38, 39, 40, 41, 42, 43, 44, 45, 46, 47, 48, 49, 50, 51
129 };
130
131 /** Mask used to extract 6 bits, used when encoding */
132 private static final int MASK_6BITS = 0x3f;
133
134 /** Mask used to extract 8 bits, used in decoding base64 bytes */
135 private static final int MASK_8BITS = 0xff;
136
137 // The static final fields above are used for the original static byte[] methods on Base64.
138 // The private member fields below are used with the new streaming approach, which requires
139 // some state be preserved between calls of encode() and decode().
140
141 /**
142 * Encode table to use: either STANDARD or URL_SAFE. Note: the DECODE_TABLE above remains static because it is able
143 * to decode both STANDARD and URL_SAFE streams, but the encodeTable must be a member variable so we can switch
144 * between the two modes.
145 */
146 private final byte[] encodeTable;
147
148 /**
149 * Line length for encoding. Not used when decoding. A value of zero or less implies no chunking of the base64
150 * encoded data.
151 */
152 private final int lineLength;
153
154 /**
155 * Line separator for encoding. Not used when decoding. Only used if lineLength > 0.
156 */
157 private final byte[] lineSeparator;
158
159 /**
160 * Convenience variable to help us determine when our buffer is going to run out of room and needs resizing.
161 * <code>decodeSize = 3 + lineSeparator.length;</code>
162 */
163 private final int decodeSize;
164
165 /**
166 * Convenience variable to help us determine when our buffer is going to run out of room and needs resizing.
167 * <code>encodeSize = 4 + lineSeparator.length;</code>
168 */
169 private final int encodeSize;
170
171 /**
172 * Buffer for streaming.
173 */
174 private byte[] buffer;
175
176 /**
177 * Position where next character should be written in the buffer.
178 */
179 private int pos;
180
181 /**
182 * Position where next character should be read from the buffer.
183 */
184 private int readPos;
185
186 /**
187 * Variable tracks how many characters have been written to the current line. Only used when encoding. We use it to
188 * make sure each encoded line never goes beyond lineLength (if lineLength > 0).
189 */
190 private int currentLinePos;
191
192 /**
193 * Writes to the buffer only occur after every 3 reads when encoding, an every 4 reads when decoding. This variable
194 * helps track that.
195 */
196 private int modulus;
197
198 /**
199 * Boolean flag to indicate the EOF has been reached. Once EOF has been reached, this Base64 object becomes useless,
200 * and must be thrown away.
201 */
202 private boolean eof;
203
204 /**
205 * Place holder for the 3 bytes we're dealing with for our base64 logic. Bitwise operations store and extract the
206 * base64 encoding or decoding from this variable.
207 */
208 private int x;
209
210 /**
211 * Creates a Base64 codec used for decoding (all modes) and encoding in URL-unsafe mode.
212 * <p>
213 * When encoding the line length is 76, the line separator is CRLF, and the encoding table is STANDARD_ENCODE_TABLE.
214 * </p>
215 *
216 * <p>
217 * When decoding all variants are supported.
218 * </p>
219 */
220 public Base64() {
221 this(false);
222 }
223
224 /**
225 * Creates a Base64 codec used for decoding (all modes) and encoding in the given URL-safe mode.
226 * <p>
227 * When encoding the line length is 76, the line separator is CRLF, and the encoding table is STANDARD_ENCODE_TABLE.
228 * </p>
229 *
230 * <p>
231 * When decoding all variants are supported.
232 * </p>
233 *
234 * @param urlSafe
235 * if <code>true</code>, URL-safe encoding is used. In most cases this should be set to
236 * <code>false</code>.
237 * @since 1.4
238 */
239 public Base64(boolean urlSafe) {
240 this(CHUNK_SIZE, CHUNK_SEPARATOR, urlSafe);
241 }
242
243 /**
244 * Creates a Base64 codec used for decoding (all modes) and encoding in URL-unsafe mode.
245 * <p>
246 * When encoding the line length is given in the constructor, the line separator is CRLF, and the encoding table is
247 * STANDARD_ENCODE_TABLE.
248 * </p>
249 * <p>
250 * Line lengths that aren't multiples of 4 will still essentially end up being multiples of 4 in the encoded data.
251 * </p>
252 * <p>
253 * When decoding all variants are supported.
254 * </p>
255 *
256 * @param lineLength
257 * Each line of encoded data will be at most of the given length (rounded down to nearest multiple of 4).
258 * If lineLength <= 0, then the output will not be divided into lines (chunks). Ignored when decoding.
259 * @since 1.4
260 */
261 public Base64(int lineLength) {
262 this(lineLength, CHUNK_SEPARATOR);
263 }
264
265 /**
266 * Creates a Base64 codec used for decoding (all modes) and encoding in URL-unsafe mode.
267 * <p>
268 * When encoding the line length and line separator are given in the constructor, and the encoding table is
269 * STANDARD_ENCODE_TABLE.
270 * </p>
271 * <p>
272 * Line lengths that aren't multiples of 4 will still essentially end up being multiples of 4 in the encoded data.
273 * </p>
274 * <p>
275 * When decoding all variants are supported.
276 * </p>
277 *
278 * @param lineLength
279 * Each line of encoded data will be at most of the given length (rounded down to nearest multiple of 4).
280 * If lineLength <= 0, then the output will not be divided into lines (chunks). Ignored when decoding.
281 * @param lineSeparator
282 * Each line of encoded data will end with this sequence of bytes.
283 * @throws IllegalArgumentException
284 * Thrown when the provided lineSeparator included some base64 characters.
285 * @since 1.4
286 */
287 public Base64(int lineLength, byte[] lineSeparator) {
288 this(lineLength, lineSeparator, false);
289 }
290
291 /**
292 * Creates a Base64 codec used for decoding (all modes) and encoding in URL-unsafe mode.
293 * <p>
294 * When encoding the line length and line separator are given in the constructor, and the encoding table is
295 * STANDARD_ENCODE_TABLE.
296 * </p>
297 * <p>
298 * Line lengths that aren't multiples of 4 will still essentially end up being multiples of 4 in the encoded data.
299 * </p>
300 * <p>
301 * When decoding all variants are supported.
302 * </p>
303 *
304 * @param lineLength
305 * Each line of encoded data will be at most of the given length (rounded down to nearest multiple of 4).
306 * If lineLength <= 0, then the output will not be divided into lines (chunks). Ignored when decoding.
307 * @param lineSeparator
308 * Each line of encoded data will end with this sequence of bytes.
309 * @param urlSafe
310 * Instead of emitting '+' and '/' we emit '-' and '_' respectively. urlSafe is only applied to encode
311 * operations. Decoding seamlessly handles both modes.
312 * @throws IllegalArgumentException
313 * The provided lineSeparator included some base64 characters. That's not going to work!
314 * @since 1.4
315 */
316 public Base64(int lineLength, byte[] lineSeparator, boolean urlSafe) {
317 if (lineSeparator == null) {
318 lineLength = 0; // disable chunk-separating
319 lineSeparator = EMPTY_BYTE_ARRAY; // this just gets ignored
320 }
321 this.lineLength = lineLength > 0 ? (lineLength / 4) * 4 : 0;
322 this.lineSeparator = new byte[lineSeparator.length];
323 System.arraycopy(lineSeparator, 0, this.lineSeparator, 0, lineSeparator.length);
324 if (lineLength > 0) {
325 this.encodeSize = 4 + lineSeparator.length;
326 } else {
327 this.encodeSize = 4;
328 }
329 this.decodeSize = this.encodeSize - 1;
330 if (containsBase64Byte(lineSeparator)) {
331 String sep = newStringUtf8(lineSeparator);
332 throw new IllegalArgumentException("lineSeperator must not contain base64 characters: [" + sep + "]");
333 }
334 this.encodeTable = urlSafe ? URL_SAFE_ENCODE_TABLE : STANDARD_ENCODE_TABLE;
335 }
336
337 /**
338 * Returns our current encode mode. True if we're URL-SAFE, false otherwise.
339 *
340 * @return true if we're in URL-SAFE mode, false otherwise.
341 * @since 1.4
342 */
343 public boolean isUrlSafe() {
344 return this.encodeTable == URL_SAFE_ENCODE_TABLE;
345 }
346
347 /**
348 * Returns true if this Base64 object has buffered data for reading.
349 *
350 * @return true if there is Base64 object still available for reading.
351 */
352 boolean hasData() {
353 return this.buffer != null;
354 }
355
356 /**
357 * Returns the amount of buffered data available for reading.
358 *
359 * @return The amount of buffered data available for reading.
360 */
361 int avail() {
362 return buffer != null ? pos - readPos : 0;
363 }
364
365 /** Doubles our buffer. */
366 private void resizeBuffer() {
367 if (buffer == null) {
368 buffer = new byte[DEFAULT_BUFFER_SIZE];
369 pos = 0;
370 readPos = 0;
371 } else {
372 byte[] b = new byte[buffer.length * DEFAULT_BUFFER_RESIZE_FACTOR];
373 System.arraycopy(buffer, 0, b, 0, buffer.length);
374 buffer = b;
375 }
376 }
377
378 /**
379 * Extracts buffered data into the provided byte[] array, starting at position bPos, up to a maximum of bAvail
380 * bytes. Returns how many bytes were actually extracted.
381 *
382 * @param b
383 * byte[] array to extract the buffered data into.
384 * @param bPos
385 * position in byte[] array to start extraction at.
386 * @param bAvail
387 * amount of bytes we're allowed to extract. We may extract fewer (if fewer are available).
388 * @return The number of bytes successfully extracted into the provided byte[] array.
389 */
390 int readResults(byte[] b, int bPos, int bAvail) {
391 if (buffer != null) {
392 int len = Math.min(avail(), bAvail);
393 if (buffer != b) {
394 System.arraycopy(buffer, readPos, b, bPos, len);
395 readPos += len;
396 if (readPos >= pos) {
397 buffer = null;
398 }
399 } else {
400 // Re-using the original consumer's output array is only
401 // allowed for one round.
402 buffer = null;
403 }
404 return len;
405 }
406 return eof ? -1 : 0;
407 }
408
409 /**
410 * Sets the streaming buffer. This is a small optimization where we try to buffer directly to the consumer's output
411 * array for one round (if the consumer calls this method first) instead of starting our own buffer.
412 *
413 * @param out
414 * byte[] array to buffer directly to.
415 * @param outPos
416 * Position to start buffering into.
417 * @param outAvail
418 * Amount of bytes available for direct buffering.
419 */
420 void setInitialBuffer(byte[] out, int outPos, int outAvail) {
421 // We can re-use consumer's original output array under
422 // special circumstances, saving on some System.arraycopy().
423 if (out != null && out.length == outAvail) {
424 buffer = out;
425 pos = outPos;
426 readPos = outPos;
427 }
428 }
429
430 /**
431 * <p>
432 * Encodes all of the provided data, starting at inPos, for inAvail bytes. Must be called at least twice: once with
433 * the data to encode, and once with inAvail set to "-1" to alert encoder that EOF has been reached, so flush last
434 * remaining bytes (if not multiple of 3).
435 * </p>
436 * <p>
437 * Thanks to "commons" project in ws.apache.org for the bitwise operations, and general approach.
438 * http://svn.apache.org/repos/asf/webservices/commons/trunk/modules/util/
439 * </p>
440 *
441 * @param in
442 * byte[] array of binary data to base64 encode.
443 * @param inPos
444 * Position to start reading data from.
445 * @param inAvail
446 * Amount of bytes available from input for encoding.
447 */
448 void encode(byte[] in, int inPos, int inAvail) {
449 if (eof) {
450 return;
451 }
452 // inAvail < 0 is how we're informed of EOF in the underlying data we're
453 // encoding.
454 if (inAvail < 0) {
455 eof = true;
456 if (buffer == null || buffer.length - pos < encodeSize) {
457 resizeBuffer();
458 }
459 switch (modulus) {
460 case 1 :
461 buffer[pos++] = encodeTable[(x >> 2) & MASK_6BITS];
462 buffer[pos++] = encodeTable[(x << 4) & MASK_6BITS];
463 // URL-SAFE skips the padding to further reduce size.
464 if (encodeTable == STANDARD_ENCODE_TABLE) {
465 buffer[pos++] = PAD;
466 buffer[pos++] = PAD;
467 }
468 break;
469
470 case 2 :
471 buffer[pos++] = encodeTable[(x >> 10) & MASK_6BITS];
472 buffer[pos++] = encodeTable[(x >> 4) & MASK_6BITS];
473 buffer[pos++] = encodeTable[(x << 2) & MASK_6BITS];
474 // URL-SAFE skips the padding to further reduce size.
475 if (encodeTable == STANDARD_ENCODE_TABLE) {
476 buffer[pos++] = PAD;
477 }
478 break;
479 default:
480 break; // other values ignored
481 }
482 if (lineLength > 0 && pos > 0) {
483 System.arraycopy(lineSeparator, 0, buffer, pos, lineSeparator.length);
484 pos += lineSeparator.length;
485 }
486 } else {
487 for (int i = 0; i < inAvail; i++) {
488 if (buffer == null || buffer.length - pos < encodeSize) {
489 resizeBuffer();
490 }
491 modulus = (++modulus) % 3;
492 int b = in[inPos++];
493 if (b < 0) {
494 b += 256;
495 }
496 x = (x << 8) + b;
497 if (0 == modulus) {
498 buffer[pos++] = encodeTable[(x >> 18) & MASK_6BITS];
499 buffer[pos++] = encodeTable[(x >> 12) & MASK_6BITS];
500 buffer[pos++] = encodeTable[(x >> 6) & MASK_6BITS];
501 buffer[pos++] = encodeTable[x & MASK_6BITS];
502 currentLinePos += 4;
503 if (lineLength > 0 && lineLength <= currentLinePos) {
504 System.arraycopy(lineSeparator, 0, buffer, pos, lineSeparator.length);
505 pos += lineSeparator.length;
506 currentLinePos = 0;
507 }
508 }
509 }
510 }
511 }
512
513 /**
514 * <p>
515 * Decodes all of the provided data, starting at inPos, for inAvail bytes. Should be called at least twice: once
516 * with the data to decode, and once with inAvail set to "-1" to alert decoder that EOF has been reached. The "-1"
517 * call is not necessary when decoding, but it doesn't hurt, either.
518 * </p>
519 * <p>
520 * Ignores all non-base64 characters. This is how chunked (e.g. 76 character) data is handled, since CR and LF are
521 * silently ignored, but has implications for other bytes, too. This method subscribes to the garbage-in,
522 * garbage-out philosophy: it will not check the provided data for validity.
523 * </p>
524 * <p>
525 * Thanks to "commons" project in ws.apache.org for the bitwise operations, and general approach.
526 * http://svn.apache.org/repos/asf/webservices/commons/trunk/modules/util/
527 * </p>
528 *
529 * @param in
530 * byte[] array of ascii data to base64 decode.
531 * @param inPos
532 * Position to start reading data from.
533 * @param inAvail
534 * Amount of bytes available from input for encoding.
535 */
536 void decode(byte[] in, int inPos, int inAvail) {
537 if (eof) {
538 return;
539 }
540 if (inAvail < 0) {
541 eof = true;
542 }
543 for (int i = 0; i < inAvail; i++) {
544 if (buffer == null || buffer.length - pos < decodeSize) {
545 resizeBuffer();
546 }
547 byte b = in[inPos++];
548 if (b == PAD) {
549 // We're done.
550 eof = true;
551 break;
552 } else {
553 if (b >= 0 && b < DECODE_TABLE.length) {
554 int result = DECODE_TABLE[b];
555 if (result >= 0) {
556 modulus = (++modulus) % 4;
557 x = (x << 6) + result;
558 if (modulus == 0) {
559 buffer[pos++] = (byte) ((x >> 16) & MASK_8BITS);
560 buffer[pos++] = (byte) ((x >> 8) & MASK_8BITS);
561 buffer[pos++] = (byte) (x & MASK_8BITS);
562 }
563 }
564 }
565 }
566 }
567
568 // Two forms of EOF as far as base64 decoder is concerned: actual
569 // EOF (-1) and first time '=' character is encountered in stream.
570 // This approach makes the '=' padding characters completely optional.
571 if (eof && modulus != 0) {
572 x = x << 6;
573 switch (modulus) {
574 case 2 :
575 x = x << 6;
576 buffer[pos++] = (byte) ((x >> 16) & MASK_8BITS);
577 break;
578 case 3 :
579 buffer[pos++] = (byte) ((x >> 16) & MASK_8BITS);
580 buffer[pos++] = (byte) ((x >> 8) & MASK_8BITS);
581 break;
582 default:
583 break; // other values ignored
584 }
585 }
586 }
587
588 /**
589 * Returns whether or not the <code>octet</code> is in the base 64 alphabet.
590 *
591 * @param octet
592 * The value to test
593 * @return <code>true</code> if the value is defined in the the base 64 alphabet, <code>false</code> otherwise.
594 * @since 1.4
595 */
596 public static boolean isBase64(byte octet) {
597 return octet == PAD || (octet >= 0 && octet < DECODE_TABLE.length && DECODE_TABLE[octet] != -1);
598 }
599
600 /**
601 * Tests a given byte array to see if it contains only valid characters within the Base64 alphabet. Currently the
602 * method treats whitespace as valid.
603 *
604 * @param arrayOctet
605 * byte array to test
606 * @return <code>true</code> if all bytes are valid characters in the Base64 alphabet or if the byte array is empty;
607 * false, otherwise
608 */
609 public static boolean isArrayByteBase64(byte[] arrayOctet) {
610 for (int i = 0; i < arrayOctet.length; i++) {
611 if (!isBase64(arrayOctet[i]) && !isWhiteSpace(arrayOctet[i])) {
612 return false;
613 }
614 }
615 return true;
616 }
617
618 /**
619 * Tests a given byte array to see if it contains only valid characters within the Base64 alphabet.
620 *
621 * @param arrayOctet
622 * byte array to test
623 * @return <code>true</code> if any byte is a valid character in the Base64 alphabet; false herwise
624 */
625 private static boolean containsBase64Byte(byte[] arrayOctet) {
626 for (byte element : arrayOctet)
627 {
628 if (isBase64(element)) {
629 return true;
630 }
631 }
632 return false;
633 }
634
635 /**
636 * Encodes binary data using the base64 algorithm but does not chunk the output.
637 *
638 * @param binaryData
639 * binary data to encode
640 * @return byte[] containing Base64 characters in their UTF-8 representation.
641 */
642 public static byte[] encodeBase64(byte[] binaryData) {
643 return encodeBase64(binaryData, false);
644 }
645
646 /**
647 * Encodes binary data using the base64 algorithm into 76 character blocks separated by CRLF.
648 * <p>
649 * For a non-chunking version, see {@link #encodeBase64StringUnChunked(byte[])}.
650 *
651 * @param binaryData
652 * binary data to encode
653 * @return String containing Base64 characters.
654 * @since 1.4
655 */
656 public static String encodeBase64String(byte[] binaryData) {
657 return newStringUtf8(encodeBase64(binaryData, true));
658 }
659
660 /**
661 * Encodes binary data using the base64 algorithm, without using chunking.
662 * <p>
663 * For a chunking version, see {@link #encodeBase64String(byte[])}.
664 *
665 * @param binaryData
666 * binary data to encode
667 * @return String containing Base64 characters.
668 * @since 3.2
669 */
670 public static String encodeBase64StringUnChunked(byte[] binaryData) {
671 return newStringUtf8(encodeBase64(binaryData, false));
672 }
673
674 /**
675 * Encodes binary data using the base64 algorithm.
676 *
677 * @param binaryData
678 * binary data to encode
679 * @param useChunking whether to split the output into chunks
680 * @return String containing Base64 characters.
681 * @since 3.2
682 */
683 public static String encodeBase64String(byte[] binaryData, boolean useChunking) {
684 return newStringUtf8(encodeBase64(binaryData, useChunking));
685 }
686
687 /**
688 * Encodes binary data using a URL-safe variation of the base64 algorithm but does not chunk the output. The
689 * url-safe variation emits - and _ instead of + and / characters.
690 *
691 * @param binaryData
692 * binary data to encode
693 * @return byte[] containing Base64 characters in their UTF-8 representation.
694 * @since 1.4
695 */
696 public static byte[] encodeBase64URLSafe(byte[] binaryData) {
697 return encodeBase64(binaryData, false, true);
698 }
699
700 /**
701 * Encodes binary data using a URL-safe variation of the base64 algorithm but does not chunk the output. The
702 * url-safe variation emits - and _ instead of + and / characters.
703 *
704 * @param binaryData
705 * binary data to encode
706 * @return String containing Base64 characters
707 * @since 1.4
708 */
709 public static String encodeBase64URLSafeString(byte[] binaryData) {
710 return newStringUtf8(encodeBase64(binaryData, false, true));
711 }
712
713 /**
714 * Encodes binary data using the base64 algorithm and chunks the encoded output into 76 character blocks
715 *
716 * @param binaryData
717 * binary data to encode
718 * @return Base64 characters chunked in 76 character blocks
719 */
720 public static byte[] encodeBase64Chunked(byte[] binaryData) {
721 return encodeBase64(binaryData, true);
722 }
723
724 /**
725 * Decodes a String containing containing characters in the Base64 alphabet.
726 *
727 * @param pArray
728 * A String containing Base64 character data
729 * @return a byte array containing binary data
730 * @since 1.4
731 */
732 public byte[] decode(String pArray) {
733 return decode(getBytesUtf8(pArray));
734 }
735
736 private byte[] getBytesUtf8(String pArray) {
737 try {
738 return pArray.getBytes("UTF8");
739 } catch (UnsupportedEncodingException e) {
740 throw new RuntimeException(e);
741 }
742 }
743
744 /**
745 * Decodes a byte[] containing containing characters in the Base64 alphabet.
746 *
747 * @param pArray
748 * A byte array containing Base64 character data
749 * @return a byte array containing binary data
750 */
751 public byte[] decode(byte[] pArray) {
752 reset();
753 if (pArray == null || pArray.length == 0) {
754 return pArray;
755 }
756 long len = (pArray.length * 3) / 4;
757 byte[] buf = new byte[(int) len];
758 setInitialBuffer(buf, 0, buf.length);
759 decode(pArray, 0, pArray.length);
760 decode(pArray, 0, -1); // Notify decoder of EOF.
761
762 // Would be nice to just return buf (like we sometimes do in the encode
763 // logic), but we have no idea what the line-length was (could even be
764 // variable). So we cannot determine ahead of time exactly how big an
765 // array is necessary. Hence the need to construct a 2nd byte array to
766 // hold the final result:
767
768 byte[] result = new byte[pos];
769 readResults(result, 0, result.length);
770 return result;
771 }
772
773 /**
774 * Encodes binary data using the base64 algorithm, optionally chunking the output into 76 character blocks.
775 *
776 * @param binaryData
777 * Array containing binary data to encode.
778 * @param isChunked
779 * if <code>true</code> this encoder will chunk the base64 output into 76 character blocks
780 * @return Base64-encoded data.
781 * @throws IllegalArgumentException
782 * Thrown when the input array needs an output array bigger than {@link Integer#MAX_VALUE}
783 */
784 public static byte[] encodeBase64(byte[] binaryData, boolean isChunked) {
785 return encodeBase64(binaryData, isChunked, false);
786 }
787
788 /**
789 * Encodes binary data using the base64 algorithm, optionally chunking the output into 76 character blocks.
790 *
791 * @param binaryData
792 * Array containing binary data to encode.
793 * @param isChunked
794 * if <code>true</code> this encoder will chunk the base64 output into 76 character blocks
795 * @param urlSafe
796 * if <code>true</code> this encoder will emit - and _ instead of the usual + and / characters.
797 * @return Base64-encoded data.
798 * @throws IllegalArgumentException
799 * Thrown when the input array needs an output array bigger than {@link Integer#MAX_VALUE}
800 * @since 1.4
801 */
802 public static byte[] encodeBase64(byte[] binaryData, boolean isChunked, boolean urlSafe) {
803 return encodeBase64(binaryData, isChunked, urlSafe, Integer.MAX_VALUE);
804 }
805
806 /**
807 * Encodes binary data using the base64 algorithm, optionally chunking the output into 76 character blocks.
808 *
809 * @param binaryData
810 * Array containing binary data to encode.
811 * @param isChunked
812 * if <code>true</code> this encoder will chunk the base64 output into 76 character blocks
813 * @param urlSafe
814 * if <code>true</code> this encoder will emit - and _ instead of the usual + and / characters.
815 * @param maxResultSize
816 * The maximum result size to accept.
817 * @return Base64-encoded data.
818 * @throws IllegalArgumentException
819 * Thrown when the input array needs an output array bigger than maxResultSize
820 * @since 1.4
821 */
822 public static byte[] encodeBase64(byte[] binaryData, boolean isChunked, boolean urlSafe, int maxResultSize) {
823 if (binaryData == null || binaryData.length == 0) {
824 return binaryData;
825 }
826
827 long len = getEncodeLength(binaryData, isChunked ? CHUNK_SIZE : 0, isChunked ? CHUNK_SEPARATOR : EMPTY_BYTE_ARRAY);
828 if (len > maxResultSize) {
829 throw new IllegalArgumentException("Input array too big, the output array would be bigger (" +
830 len +
831 ") than the specified maxium size of " +
832 maxResultSize);
833 }
834
835 Base64 b64 = isChunked ? new Base64(urlSafe) : new Base64(0, CHUNK_SEPARATOR, urlSafe);
836 return b64.encode(binaryData);
837 }
838
839 /**
840 * Decodes a Base64 String into octets
841 *
842 * @param base64String
843 * String containing Base64 data
844 * @return Array containing decoded data.
845 * @since 1.4
846 */
847 public static byte[] decodeBase64(String base64String) {
848 return new Base64().decode(base64String);
849 }
850
851 /**
852 * Decodes Base64 data into octets
853 *
854 * @param base64Data
855 * Byte array containing Base64 data
856 * @return Array containing decoded data.
857 */
858 public static byte[] decodeBase64(byte[] base64Data) {
859 return new Base64().decode(base64Data);
860 }
861
862
863
864 /**
865 * Checks if a byte value is whitespace or not.
866 *
867 * @param byteToCheck
868 * the byte to check
869 * @return true if byte is whitespace, false otherwise
870 */
871 private static boolean isWhiteSpace(byte byteToCheck) {
872 switch (byteToCheck) {
873 case ' ' :
874 case '\n' :
875 case '\r' :
876 case '\t' :
877 return true;
878 default :
879 return false;
880 }
881 }
882
883 /**
884 * Encodes a byte[] containing binary data, into a String containing characters in the Base64 alphabet.
885 *
886 * @param pArray
887 * a byte array containing binary data
888 * @return A String containing only Base64 character data
889 * @since 1.4
890 */
891 public String encodeToString(byte[] pArray) {
892 return newStringUtf8(encode(pArray));
893 }
894
895 private static String newStringUtf8(byte[] encode) {
896 String str = null;
897 try {
898 str = new String(encode, "UTF8");
899 } catch (UnsupportedEncodingException ue) {
900 throw new RuntimeException(ue);
901 }
902 return str;
903 }
904
905 /**
906 * Encodes a byte[] containing binary data, into a byte[] containing characters in the Base64 alphabet.
907 *
908 * @param pArray
909 * a byte array containing binary data
910 * @return A byte array containing only Base64 character data
911 */
912 public byte[] encode(byte[] pArray) {
913 reset();
914 if (pArray == null || pArray.length == 0) {
915 return pArray;
916 }
917 long len = getEncodeLength(pArray, lineLength, lineSeparator);
918 byte[] buf = new byte[(int) len];
919 setInitialBuffer(buf, 0, buf.length);
920 encode(pArray, 0, pArray.length);
921 encode(pArray, 0, -1); // Notify encoder of EOF.
922 // Encoder might have resized, even though it was unnecessary.
923 if (buffer != buf) {
924 readResults(buf, 0, buf.length);
925 }
926 // In URL-SAFE mode we skip the padding characters, so sometimes our
927 // final length is a bit smaller.
928 if (isUrlSafe() && pos < buf.length) {
929 byte[] smallerBuf = new byte[pos];
930 System.arraycopy(buf, 0, smallerBuf, 0, pos);
931 buf = smallerBuf;
932 }
933 return buf;
934 }
935
936 /**
937 * Pre-calculates the amount of space needed to base64-encode the supplied array.
938 *
939 * @param pArray byte[] array which will later be encoded
940 * @param chunkSize line-length of the output (<= 0 means no chunking) between each
941 * chunkSeparator (e.g. CRLF).
942 * @param chunkSeparator the sequence of bytes used to separate chunks of output (e.g. CRLF).
943 *
944 * @return amount of space needed to encoded the supplied array. Returns
945 * a long since a max-len array will require Integer.MAX_VALUE + 33%.
946 */
947 private static long getEncodeLength(byte[] pArray, int chunkSize, byte[] chunkSeparator) {
948 // base64 always encodes to multiples of 4.
949 chunkSize = (chunkSize / 4) * 4;
950
951 long len = (pArray.length * 4) / 3;
952 long mod = len % 4;
953 if (mod != 0) {
954 len += 4 - mod;
955 }
956 if (chunkSize > 0) {
957 boolean lenChunksPerfectly = len % chunkSize == 0;
958 len += (len / chunkSize) * chunkSeparator.length;
959 if (!lenChunksPerfectly) {
960 len += chunkSeparator.length;
961 }
962 }
963 return len;
964 }
965
966 // Implementation of integer encoding used for crypto
967 /**
968 * Decodes a byte64-encoded integer according to crypto standards such as W3C's XML-Signature
969 *
970 * @param pArray
971 * a byte array containing base64 character data
972 * @return A BigInteger
973 * @since 1.4
974 */
975 public static BigInteger decodeInteger(byte[] pArray) {
976 return new BigInteger(1, decodeBase64(pArray));
977 }
978
979 /**
980 * Encodes to a byte64-encoded integer according to crypto standards such as W3C's XML-Signature
981 *
982 * @param bigInt
983 * a BigInteger
984 * @return A byte array containing base64 character data
985 * @throws NullPointerException
986 * if null is passed in
987 * @since 1.4
988 */
989 public static byte[] encodeInteger(BigInteger bigInt) {
990 if (bigInt == null) {
991 throw new NullPointerException("encodeInteger called with null parameter");
992 }
993 return encodeBase64(toIntegerBytes(bigInt), false);
994 }
995
996 /**
997 * Returns a byte-array representation of a <code>BigInteger</code> without sign bit.
998 *
999 * @param bigInt
1000 * <code>BigInteger</code> to be converted
1001 * @return a byte array representation of the BigInteger parameter
1002 */
1003 static byte[] toIntegerBytes(BigInteger bigInt) {
1004 int bitlen = bigInt.bitLength();
1005 // round bitlen
1006 bitlen = ((bitlen + 7) >> 3) << 3;
1007 byte[] bigBytes = bigInt.toByteArray();
1008
1009 if (((bigInt.bitLength() % 8) != 0) && (((bigInt.bitLength() / 8) + 1) == (bitlen / 8))) {
1010 return bigBytes;
1011 }
1012 // set up params for copying everything but sign bit
1013 int startSrc = 0;
1014 int len = bigBytes.length;
1015
1016 // if bigInt is exactly byte-aligned, just skip signbit in copy
1017 if ((bigInt.bitLength() % 8) == 0) {
1018 startSrc = 1;
1019 len--;
1020 }
1021 int startDst = bitlen / 8 - len; // to pad w/ nulls as per spec
1022 byte[] resizedBytes = new byte[bitlen / 8];
1023 System.arraycopy(bigBytes, startSrc, resizedBytes, startDst, len);
1024 return resizedBytes;
1025 }
1026
1027 /**
1028 * Resets this Base64 object to its initial newly constructed state.
1029 */
1030 private void reset() {
1031 buffer = null;
1032 pos = 0;
1033 readPos = 0;
1034 currentLinePos = 0;
1035 modulus = 0;
1036 eof = false;
1037 }
1038
1039 // Getters for use in testing
1040
1041 int getLineLength() {
1042 return lineLength;
1043 }
1044
1045 byte[] getLineSeparator() {
1046 return lineSeparator.clone();
1047 }
1048 }