1 /*
2 * Licensed to the Apache Software Foundation (ASF) under one or more
3 * contributor license agreements. See the NOTICE file distributed with
4 * this work for additional information regarding copyright ownership.
5 * The ASF licenses this file to You under the Apache License, Version 2.0
6 * (the "License"); you may not use this file except in compliance with
7 * the License. You may obtain a copy of the License at
8 *
9 * http://www.apache.org/licenses/LICENSE-2.0
10 *
11 * Unless required by applicable law or agreed to in writing, software
12 * distributed under the License is distributed on an "AS IS" BASIS,
13 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
14 * See the License for the specific language governing permissions and
15 * limitations under the License.
16 */
17
18 package org.apache.commons.codec.binary;
19
20 import java.math.BigInteger;
21
22 /**
23 * Provides Base64 encoding and decoding as defined by <a href="http://www.ietf.org/rfc/rfc2045.txt">RFC 2045</a>.
24 *
25 * <p>
26 * This class implements section <cite>6.8. Base64 Content-Transfer-Encoding</cite> from RFC 2045 <cite>Multipurpose
27 * Internet Mail Extensions (MIME) Part One: Format of Internet Message Bodies</cite> by Freed and Borenstein.
28 * </p>
29 * <p>
30 * The class can be parameterized in the following manner with various constructors:
31 * <ul>
32 * <li>URL-safe mode: Default off.</li>
33 * <li>Line length: Default 76. Line length that aren't multiples of 4 will still essentially end up being multiples of
34 * 4 in the encoded data.
35 * <li>Line separator: Default is CRLF ("\r\n")</li>
36 * </ul>
37 * </p>
38 * <p>
39 * Since this class operates directly on byte streams, and not character streams, it is hard-coded to only
40 * encode/decode character encodings which are compatible with the lower 127 ASCII chart (ISO-8859-1, Windows-1252,
41 * UTF-8, etc).
42 * </p>
43 * <p>
44 * This class is thread-safe.
45 * </p>
46 *
47 * @see <a href="http://www.ietf.org/rfc/rfc2045.txt">RFC 2045</a>
48 * @since 1.0
49 * @version $Id: Base64.html 889935 2013-12-11 05:05:13Z ggregory $
50 */
51 public class Base64 extends BaseNCodec {
52
53 /**
54 * BASE32 characters are 6 bits in length.
55 * They are formed by taking a block of 3 octets to form a 24-bit string,
56 * which is converted into 4 BASE64 characters.
57 */
58 private static final int BITS_PER_ENCODED_BYTE = 6;
59 private static final int BYTES_PER_UNENCODED_BLOCK = 3;
60 private static final int BYTES_PER_ENCODED_BLOCK = 4;
61
62 /**
63 * Chunk separator per RFC 2045 section 2.1.
64 *
65 * <p>
66 * N.B. The next major release may break compatibility and make this field private.
67 * </p>
68 *
69 * @see <a href="http://www.ietf.org/rfc/rfc2045.txt">RFC 2045 section 2.1</a>
70 */
71 static final byte[] CHUNK_SEPARATOR = {'\r', '\n'};
72
73 /**
74 * This array is a lookup table that translates 6-bit positive integer index values into their "Base64 Alphabet"
75 * equivalents as specified in Table 1 of RFC 2045.
76 *
77 * Thanks to "commons" project in ws.apache.org for this code.
78 * http://svn.apache.org/repos/asf/webservices/commons/trunk/modules/util/
79 */
80 private static final byte[] STANDARD_ENCODE_TABLE = {
81 'A', 'B', 'C', 'D', 'E', 'F', 'G', 'H', 'I', 'J', 'K', 'L', 'M',
82 'N', 'O', 'P', 'Q', 'R', 'S', 'T', 'U', 'V', 'W', 'X', 'Y', 'Z',
83 'a', 'b', 'c', 'd', 'e', 'f', 'g', 'h', 'i', 'j', 'k', 'l', 'm',
84 'n', 'o', 'p', 'q', 'r', 's', 't', 'u', 'v', 'w', 'x', 'y', 'z',
85 '0', '1', '2', '3', '4', '5', '6', '7', '8', '9', '+', '/'
86 };
87
88 /**
89 * This is a copy of the STANDARD_ENCODE_TABLE above, but with + and /
90 * changed to - and _ to make the encoded Base64 results more URL-SAFE.
91 * This table is only used when the Base64's mode is set to URL-SAFE.
92 */
93 private static final byte[] URL_SAFE_ENCODE_TABLE = {
94 'A', 'B', 'C', 'D', 'E', 'F', 'G', 'H', 'I', 'J', 'K', 'L', 'M',
95 'N', 'O', 'P', 'Q', 'R', 'S', 'T', 'U', 'V', 'W', 'X', 'Y', 'Z',
96 'a', 'b', 'c', 'd', 'e', 'f', 'g', 'h', 'i', 'j', 'k', 'l', 'm',
97 'n', 'o', 'p', 'q', 'r', 's', 't', 'u', 'v', 'w', 'x', 'y', 'z',
98 '0', '1', '2', '3', '4', '5', '6', '7', '8', '9', '-', '_'
99 };
100
101 /**
102 * This array is a lookup table that translates Unicode characters drawn from the "Base64 Alphabet" (as specified
103 * in Table 1 of RFC 2045) into their 6-bit positive integer equivalents. Characters that are not in the Base64
104 * alphabet but fall within the bounds of the array are translated to -1.
105 *
106 * Note: '+' and '-' both decode to 62. '/' and '_' both decode to 63. This means decoder seamlessly handles both
107 * URL_SAFE and STANDARD base64. (The encoder, on the other hand, needs to know ahead of time what to emit).
108 *
109 * Thanks to "commons" project in ws.apache.org for this code.
110 * http://svn.apache.org/repos/asf/webservices/commons/trunk/modules/util/
111 */
112 private static final byte[] DECODE_TABLE = {
113 -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1,
114 -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1,
115 -1, -1, -1, -1, -1, -1, -1, -1, -1, 62, -1, 62, -1, 63, 52, 53, 54,
116 55, 56, 57, 58, 59, 60, 61, -1, -1, -1, -1, -1, -1, -1, 0, 1, 2, 3, 4,
117 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23,
118 24, 25, -1, -1, -1, -1, 63, -1, 26, 27, 28, 29, 30, 31, 32, 33, 34,
119 35, 36, 37, 38, 39, 40, 41, 42, 43, 44, 45, 46, 47, 48, 49, 50, 51
120 };
121
122 /**
123 * Base64 uses 6-bit fields.
124 */
125 /** Mask used to extract 6 bits, used when encoding */
126 private static final int MASK_6BITS = 0x3f;
127
128 // The static final fields above are used for the original static byte[] methods on Base64.
129 // The private member fields below are used with the new streaming approach, which requires
130 // some state be preserved between calls of encode() and decode().
131
132 /**
133 * Encode table to use: either STANDARD or URL_SAFE. Note: the DECODE_TABLE above remains static because it is able
134 * to decode both STANDARD and URL_SAFE streams, but the encodeTable must be a member variable so we can switch
135 * between the two modes.
136 */
137 private final byte[] encodeTable;
138
139 // Only one decode table currently; keep for consistency with Base32 code
140 private final byte[] decodeTable = DECODE_TABLE;
141
142 /**
143 * Line separator for encoding. Not used when decoding. Only used if lineLength > 0.
144 */
145 private final byte[] lineSeparator;
146
147 /**
148 * Convenience variable to help us determine when our buffer is going to run out of room and needs resizing.
149 * <code>decodeSize = 3 + lineSeparator.length;</code>
150 */
151 private final int decodeSize;
152
153 /**
154 * Convenience variable to help us determine when our buffer is going to run out of room and needs resizing.
155 * <code>encodeSize = 4 + lineSeparator.length;</code>
156 */
157 private final int encodeSize;
158
159 /**
160 * Creates a Base64 codec used for decoding (all modes) and encoding in URL-unsafe mode.
161 * <p>
162 * When encoding the line length is 0 (no chunking), and the encoding table is STANDARD_ENCODE_TABLE.
163 * </p>
164 *
165 * <p>
166 * When decoding all variants are supported.
167 * </p>
168 */
169 public Base64() {
170 this(0);
171 }
172
173 /**
174 * Creates a Base64 codec used for decoding (all modes) and encoding in the given URL-safe mode.
175 * <p>
176 * When encoding the line length is 76, the line separator is CRLF, and the encoding table is
177 * STANDARD_ENCODE_TABLE.
178 * </p>
179 *
180 * <p>
181 * When decoding all variants are supported.
182 * </p>
183 *
184 * @param urlSafe
185 * if {@code true}, URL-safe encoding is used. In most cases this should be set to {@code false}.
186 * @since 1.4
187 */
188 public Base64(boolean urlSafe) {
189 this(MIME_CHUNK_SIZE, CHUNK_SEPARATOR, urlSafe);
190 }
191
192 /**
193 * Creates a Base64 codec used for decoding (all modes) and encoding in URL-unsafe mode.
194 * <p>
195 * When encoding the line length is given in the constructor, the line separator is CRLF, and the encoding table is
196 * STANDARD_ENCODE_TABLE.
197 * </p>
198 * <p>
199 * Line lengths that aren't multiples of 4 will still essentially end up being multiples of 4 in the encoded data.
200 * </p>
201 * <p>
202 * When decoding all variants are supported.
203 * </p>
204 *
205 * @param lineLength
206 * Each line of encoded data will be at most of the given length (rounded down to nearest multiple of
207 * 4). If lineLength <= 0, then the output will not be divided into lines (chunks). Ignored when
208 * decoding.
209 * @since 1.4
210 */
211 public Base64(int lineLength) {
212 this(lineLength, CHUNK_SEPARATOR);
213 }
214
215 /**
216 * Creates a Base64 codec used for decoding (all modes) and encoding in URL-unsafe mode.
217 * <p>
218 * When encoding the line length and line separator are given in the constructor, and the encoding table is
219 * STANDARD_ENCODE_TABLE.
220 * </p>
221 * <p>
222 * Line lengths that aren't multiples of 4 will still essentially end up being multiples of 4 in the encoded data.
223 * </p>
224 * <p>
225 * When decoding all variants are supported.
226 * </p>
227 *
228 * @param lineLength
229 * Each line of encoded data will be at most of the given length (rounded down to nearest multiple of
230 * 4). If lineLength <= 0, then the output will not be divided into lines (chunks). Ignored when
231 * decoding.
232 * @param lineSeparator
233 * Each line of encoded data will end with this sequence of bytes.
234 * @throws IllegalArgumentException
235 * Thrown when the provided lineSeparator included some base64 characters.
236 * @since 1.4
237 */
238 public Base64(int lineLength, byte[] lineSeparator) {
239 this(lineLength, lineSeparator, false);
240 }
241
242 /**
243 * Creates a Base64 codec used for decoding (all modes) and encoding in URL-unsafe mode.
244 * <p>
245 * When encoding the line length and line separator are given in the constructor, and the encoding table is
246 * STANDARD_ENCODE_TABLE.
247 * </p>
248 * <p>
249 * Line lengths that aren't multiples of 4 will still essentially end up being multiples of 4 in the encoded data.
250 * </p>
251 * <p>
252 * When decoding all variants are supported.
253 * </p>
254 *
255 * @param lineLength
256 * Each line of encoded data will be at most of the given length (rounded down to nearest multiple of
257 * 4). If lineLength <= 0, then the output will not be divided into lines (chunks). Ignored when
258 * decoding.
259 * @param lineSeparator
260 * Each line of encoded data will end with this sequence of bytes.
261 * @param urlSafe
262 * Instead of emitting '+' and '/' we emit '-' and '_' respectively. urlSafe is only applied to encode
263 * operations. Decoding seamlessly handles both modes.
264 * @throws IllegalArgumentException
265 * The provided lineSeparator included some base64 characters. That's not going to work!
266 * @since 1.4
267 */
268 public Base64(int lineLength, byte[] lineSeparator, boolean urlSafe) {
269 super(BYTES_PER_UNENCODED_BLOCK, BYTES_PER_ENCODED_BLOCK,
270 lineLength,
271 lineSeparator == null ? 0 : lineSeparator.length);
272 // TODO could be simplified if there is no requirement to reject invalid line sep when length <=0
273 // @see test case Base64Test.testConstructors()
274 if (lineSeparator != null) {
275 if (containsAlphabetOrPad(lineSeparator)) {
276 String sep = StringUtils.newStringUtf8(lineSeparator);
277 throw new IllegalArgumentException("lineSeparator must not contain base64 characters: [" + sep + "]");
278 }
279 if (lineLength > 0){ // null line-sep forces no chunking rather than throwing IAE
280 this.encodeSize = BYTES_PER_ENCODED_BLOCK + lineSeparator.length;
281 this.lineSeparator = new byte[lineSeparator.length];
282 System.arraycopy(lineSeparator, 0, this.lineSeparator, 0, lineSeparator.length);
283 } else {
284 this.encodeSize = BYTES_PER_ENCODED_BLOCK;
285 this.lineSeparator = null;
286 }
287 } else {
288 this.encodeSize = BYTES_PER_ENCODED_BLOCK;
289 this.lineSeparator = null;
290 }
291 this.decodeSize = this.encodeSize - 1;
292 this.encodeTable = urlSafe ? URL_SAFE_ENCODE_TABLE : STANDARD_ENCODE_TABLE;
293 }
294
295 /**
296 * Returns our current encode mode. True if we're URL-SAFE, false otherwise.
297 *
298 * @return true if we're in URL-SAFE mode, false otherwise.
299 * @since 1.4
300 */
301 public boolean isUrlSafe() {
302 return this.encodeTable == URL_SAFE_ENCODE_TABLE;
303 }
304
305 /**
306 * <p>
307 * Encodes all of the provided data, starting at inPos, for inAvail bytes. Must be called at least twice: once with
308 * the data to encode, and once with inAvail set to "-1" to alert encoder that EOF has been reached, so flush last
309 * remaining bytes (if not multiple of 3).
310 * </p>
311 * <p>
312 * Thanks to "commons" project in ws.apache.org for the bitwise operations, and general approach.
313 * http://svn.apache.org/repos/asf/webservices/commons/trunk/modules/util/
314 * </p>
315 *
316 * @param in
317 * byte[] array of binary data to base64 encode.
318 * @param inPos
319 * Position to start reading data from.
320 * @param inAvail
321 * Amount of bytes available from input for encoding.
322 * @param context
323 * the context to be used
324 */
325 @Override
326 void encode(byte[] in, int inPos, int inAvail, Context context) {
327 if (context.eof) {
328 return;
329 }
330 // inAvail < 0 is how we're informed of EOF in the underlying data we're
331 // encoding.
332 if (inAvail < 0) {
333 context.eof = true;
334 if (0 == context.modulus && lineLength == 0) {
335 return; // no leftovers to process and not using chunking
336 }
337 final byte[] buffer = ensureBufferSize(encodeSize, context);
338 final int savedPos = context.pos;
339 switch (context.modulus) { // 0-2
340 case 0 : // nothing to do here
341 break;
342 case 1 : // 8 bits = 6 + 2
343 // top 6 bits:
344 buffer[context.pos++] = encodeTable[(context.ibitWorkArea >> 2) & MASK_6BITS];
345 // remaining 2:
346 buffer[context.pos++] = encodeTable[(context.ibitWorkArea << 4) & MASK_6BITS];
347 // URL-SAFE skips the padding to further reduce size.
348 if (encodeTable == STANDARD_ENCODE_TABLE) {
349 buffer[context.pos++] = PAD;
350 buffer[context.pos++] = PAD;
351 }
352 break;
353
354 case 2 : // 16 bits = 6 + 6 + 4
355 buffer[context.pos++] = encodeTable[(context.ibitWorkArea >> 10) & MASK_6BITS];
356 buffer[context.pos++] = encodeTable[(context.ibitWorkArea >> 4) & MASK_6BITS];
357 buffer[context.pos++] = encodeTable[(context.ibitWorkArea << 2) & MASK_6BITS];
358 // URL-SAFE skips the padding to further reduce size.
359 if (encodeTable == STANDARD_ENCODE_TABLE) {
360 buffer[context.pos++] = PAD;
361 }
362 break;
363 default:
364 throw new IllegalStateException("Impossible modulus "+context.modulus);
365 }
366 context.currentLinePos += context.pos - savedPos; // keep track of current line position
367 // if currentPos == 0 we are at the start of a line, so don't add CRLF
368 if (lineLength > 0 && context.currentLinePos > 0) {
369 System.arraycopy(lineSeparator, 0, buffer, context.pos, lineSeparator.length);
370 context.pos += lineSeparator.length;
371 }
372 } else {
373 for (int i = 0; i < inAvail; i++) {
374 final byte[] buffer = ensureBufferSize(encodeSize, context);
375 context.modulus = (context.modulus+1) % BYTES_PER_UNENCODED_BLOCK;
376 int b = in[inPos++];
377 if (b < 0) {
378 b += 256;
379 }
380 context.ibitWorkArea = (context.ibitWorkArea << 8) + b; // BITS_PER_BYTE
381 if (0 == context.modulus) { // 3 bytes = 24 bits = 4 * 6 bits to extract
382 buffer[context.pos++] = encodeTable[(context.ibitWorkArea >> 18) & MASK_6BITS];
383 buffer[context.pos++] = encodeTable[(context.ibitWorkArea >> 12) & MASK_6BITS];
384 buffer[context.pos++] = encodeTable[(context.ibitWorkArea >> 6) & MASK_6BITS];
385 buffer[context.pos++] = encodeTable[context.ibitWorkArea & MASK_6BITS];
386 context.currentLinePos += BYTES_PER_ENCODED_BLOCK;
387 if (lineLength > 0 && lineLength <= context.currentLinePos) {
388 System.arraycopy(lineSeparator, 0, buffer, context.pos, lineSeparator.length);
389 context.pos += lineSeparator.length;
390 context.currentLinePos = 0;
391 }
392 }
393 }
394 }
395 }
396
397 /**
398 * <p>
399 * Decodes all of the provided data, starting at inPos, for inAvail bytes. Should be called at least twice: once
400 * with the data to decode, and once with inAvail set to "-1" to alert decoder that EOF has been reached. The "-1"
401 * call is not necessary when decoding, but it doesn't hurt, either.
402 * </p>
403 * <p>
404 * Ignores all non-base64 characters. This is how chunked (e.g. 76 character) data is handled, since CR and LF are
405 * silently ignored, but has implications for other bytes, too. This method subscribes to the garbage-in,
406 * garbage-out philosophy: it will not check the provided data for validity.
407 * </p>
408 * <p>
409 * Thanks to "commons" project in ws.apache.org for the bitwise operations, and general approach.
410 * http://svn.apache.org/repos/asf/webservices/commons/trunk/modules/util/
411 * </p>
412 *
413 * @param in
414 * byte[] array of ascii data to base64 decode.
415 * @param inPos
416 * Position to start reading data from.
417 * @param inAvail
418 * Amount of bytes available from input for encoding.
419 * @param context
420 * the context to be used
421 */
422 @Override
423 void decode(byte[] in, int inPos, int inAvail, Context context) {
424 if (context.eof) {
425 return;
426 }
427 if (inAvail < 0) {
428 context.eof = true;
429 }
430 for (int i = 0; i < inAvail; i++) {
431 final byte[] buffer = ensureBufferSize(decodeSize, context);
432 final byte b = in[inPos++];
433 if (b == PAD) {
434 // We're done.
435 context.eof = true;
436 break;
437 } else {
438 if (b >= 0 && b < DECODE_TABLE.length) {
439 final int result = DECODE_TABLE[b];
440 if (result >= 0) {
441 context.modulus = (context.modulus+1) % BYTES_PER_ENCODED_BLOCK;
442 context.ibitWorkArea = (context.ibitWorkArea << BITS_PER_ENCODED_BYTE) + result;
443 if (context.modulus == 0) {
444 buffer[context.pos++] = (byte) ((context.ibitWorkArea >> 16) & MASK_8BITS);
445 buffer[context.pos++] = (byte) ((context.ibitWorkArea >> 8) & MASK_8BITS);
446 buffer[context.pos++] = (byte) (context.ibitWorkArea & MASK_8BITS);
447 }
448 }
449 }
450 }
451 }
452
453 // Two forms of EOF as far as base64 decoder is concerned: actual
454 // EOF (-1) and first time '=' character is encountered in stream.
455 // This approach makes the '=' padding characters completely optional.
456 if (context.eof && context.modulus != 0) {
457 final byte[] buffer = ensureBufferSize(decodeSize, context);
458
459 // We have some spare bits remaining
460 // Output all whole multiples of 8 bits and ignore the rest
461 switch (context.modulus) {
462 // case 0 : // impossible, as excluded above
463 case 1 : // 6 bits - ignore entirely
464 // TODO not currently tested; perhaps it is impossible?
465 break;
466 case 2 : // 12 bits = 8 + 4
467 context.ibitWorkArea = context.ibitWorkArea >> 4; // dump the extra 4 bits
468 buffer[context.pos++] = (byte) ((context.ibitWorkArea) & MASK_8BITS);
469 break;
470 case 3 : // 18 bits = 8 + 8 + 2
471 context.ibitWorkArea = context.ibitWorkArea >> 2; // dump 2 bits
472 buffer[context.pos++] = (byte) ((context.ibitWorkArea >> 8) & MASK_8BITS);
473 buffer[context.pos++] = (byte) ((context.ibitWorkArea) & MASK_8BITS);
474 break;
475 default:
476 throw new IllegalStateException("Impossible modulus "+context.modulus);
477 }
478 }
479 }
480
481 /**
482 * Tests a given byte array to see if it contains only valid characters within the Base64 alphabet. Currently the
483 * method treats whitespace as valid.
484 *
485 * @param arrayOctet
486 * byte array to test
487 * @return {@code true} if all bytes are valid characters in the Base64 alphabet or if the byte array is empty;
488 * {@code false}, otherwise
489 * @deprecated 1.5 Use {@link #isBase64(byte[])}, will be removed in 2.0.
490 */
491 @Deprecated
492 public static boolean isArrayByteBase64(byte[] arrayOctet) {
493 return isBase64(arrayOctet);
494 }
495
496 /**
497 * Returns whether or not the <code>octet</code> is in the base 64 alphabet.
498 *
499 * @param octet
500 * The value to test
501 * @return {@code true} if the value is defined in the the base 64 alphabet, {@code false} otherwise.
502 * @since 1.4
503 */
504 public static boolean isBase64(byte octet) {
505 return octet == PAD_DEFAULT || (octet >= 0 && octet < DECODE_TABLE.length && DECODE_TABLE[octet] != -1);
506 }
507
508 /**
509 * Tests a given String to see if it contains only valid characters within the Base64 alphabet. Currently the
510 * method treats whitespace as valid.
511 *
512 * @param base64
513 * String to test
514 * @return {@code true} if all characters in the String are valid characters in the Base64 alphabet or if
515 * the String is empty; {@code false}, otherwise
516 * @since 1.5
517 */
518 public static boolean isBase64(String base64) {
519 return isBase64(StringUtils.getBytesUtf8(base64));
520 }
521
522 /**
523 * Tests a given byte array to see if it contains only valid characters within the Base64 alphabet. Currently the
524 * method treats whitespace as valid.
525 *
526 * @param arrayOctet
527 * byte array to test
528 * @return {@code true} if all bytes are valid characters in the Base64 alphabet or if the byte array is empty;
529 * {@code false}, otherwise
530 * @since 1.5
531 */
532 public static boolean isBase64(byte[] arrayOctet) {
533 for (int i = 0; i < arrayOctet.length; i++) {
534 if (!isBase64(arrayOctet[i]) && !isWhiteSpace(arrayOctet[i])) {
535 return false;
536 }
537 }
538 return true;
539 }
540
541 /**
542 * Encodes binary data using the base64 algorithm but does not chunk the output.
543 *
544 * @param binaryData
545 * binary data to encode
546 * @return byte[] containing Base64 characters in their UTF-8 representation.
547 */
548 public static byte[] encodeBase64(byte[] binaryData) {
549 return encodeBase64(binaryData, false);
550 }
551
552 /**
553 * Encodes binary data using the base64 algorithm but does not chunk the output.
554 *
555 * NOTE: We changed the behaviour of this method from multi-line chunking (commons-codec-1.4) to
556 * single-line non-chunking (commons-codec-1.5).
557 *
558 * @param binaryData
559 * binary data to encode
560 * @return String containing Base64 characters.
561 * @since 1.4 (NOTE: 1.4 chunked the output, whereas 1.5 does not).
562 */
563 public static String encodeBase64String(byte[] binaryData) {
564 return StringUtils.newStringUtf8(encodeBase64(binaryData, false));
565 }
566
567 /**
568 * Encodes binary data using a URL-safe variation of the base64 algorithm but does not chunk the output. The
569 * url-safe variation emits - and _ instead of + and / characters.
570 *
571 * @param binaryData
572 * binary data to encode
573 * @return byte[] containing Base64 characters in their UTF-8 representation.
574 * @since 1.4
575 */
576 public static byte[] encodeBase64URLSafe(byte[] binaryData) {
577 return encodeBase64(binaryData, false, true);
578 }
579
580 /**
581 * Encodes binary data using a URL-safe variation of the base64 algorithm but does not chunk the output. The
582 * url-safe variation emits - and _ instead of + and / characters.
583 *
584 * @param binaryData
585 * binary data to encode
586 * @return String containing Base64 characters
587 * @since 1.4
588 */
589 public static String encodeBase64URLSafeString(byte[] binaryData) {
590 return StringUtils.newStringUtf8(encodeBase64(binaryData, false, true));
591 }
592
593 /**
594 * Encodes binary data using the base64 algorithm and chunks the encoded output into 76 character blocks
595 *
596 * @param binaryData
597 * binary data to encode
598 * @return Base64 characters chunked in 76 character blocks
599 */
600 public static byte[] encodeBase64Chunked(byte[] binaryData) {
601 return encodeBase64(binaryData, true);
602 }
603
604 /**
605 * Encodes binary data using the base64 algorithm, optionally chunking the output into 76 character blocks.
606 *
607 * @param binaryData
608 * Array containing binary data to encode.
609 * @param isChunked
610 * if {@code true} this encoder will chunk the base64 output into 76 character blocks
611 * @return Base64-encoded data.
612 * @throws IllegalArgumentException
613 * Thrown when the input array needs an output array bigger than {@link Integer#MAX_VALUE}
614 */
615 public static byte[] encodeBase64(byte[] binaryData, boolean isChunked) {
616 return encodeBase64(binaryData, isChunked, false);
617 }
618
619 /**
620 * Encodes binary data using the base64 algorithm, optionally chunking the output into 76 character blocks.
621 *
622 * @param binaryData
623 * Array containing binary data to encode.
624 * @param isChunked
625 * if {@code true} this encoder will chunk the base64 output into 76 character blocks
626 * @param urlSafe
627 * if {@code true} this encoder will emit - and _ instead of the usual + and / characters.
628 * @return Base64-encoded data.
629 * @throws IllegalArgumentException
630 * Thrown when the input array needs an output array bigger than {@link Integer#MAX_VALUE}
631 * @since 1.4
632 */
633 public static byte[] encodeBase64(byte[] binaryData, boolean isChunked, boolean urlSafe) {
634 return encodeBase64(binaryData, isChunked, urlSafe, Integer.MAX_VALUE);
635 }
636
637 /**
638 * Encodes binary data using the base64 algorithm, optionally chunking the output into 76 character blocks.
639 *
640 * @param binaryData
641 * Array containing binary data to encode.
642 * @param isChunked
643 * if {@code true} this encoder will chunk the base64 output into 76 character blocks
644 * @param urlSafe
645 * if {@code true} this encoder will emit - and _ instead of the usual + and / characters.
646 * @param maxResultSize
647 * The maximum result size to accept.
648 * @return Base64-encoded data.
649 * @throws IllegalArgumentException
650 * Thrown when the input array needs an output array bigger than maxResultSize
651 * @since 1.4
652 */
653 public static byte[] encodeBase64(byte[] binaryData, boolean isChunked, boolean urlSafe, int maxResultSize) {
654 if (binaryData == null || binaryData.length == 0) {
655 return binaryData;
656 }
657
658 // Create this so can use the super-class method
659 // Also ensures that the same roundings are performed by the ctor and the code
660 Base64 b64 = isChunked ? new Base64(urlSafe) : new Base64(0, CHUNK_SEPARATOR, urlSafe);
661 long len = b64.getEncodedLength(binaryData);
662 if (len > maxResultSize) {
663 throw new IllegalArgumentException("Input array too big, the output array would be bigger (" +
664 len +
665 ") than the specified maximum size of " +
666 maxResultSize);
667 }
668
669 return b64.encode(binaryData);
670 }
671
672 /**
673 * Decodes a Base64 String into octets
674 *
675 * @param base64String
676 * String containing Base64 data
677 * @return Array containing decoded data.
678 * @since 1.4
679 */
680 public static byte[] decodeBase64(String base64String) {
681 return new Base64().decode(base64String);
682 }
683
684 /**
685 * Decodes Base64 data into octets
686 *
687 * @param base64Data
688 * Byte array containing Base64 data
689 * @return Array containing decoded data.
690 */
691 public static byte[] decodeBase64(byte[] base64Data) {
692 return new Base64().decode(base64Data);
693 }
694
695 // Implementation of the Encoder Interface
696
697 // Implementation of integer encoding used for crypto
698 /**
699 * Decodes a byte64-encoded integer according to crypto standards such as W3C's XML-Signature
700 *
701 * @param pArray
702 * a byte array containing base64 character data
703 * @return A BigInteger
704 * @since 1.4
705 */
706 public static BigInteger decodeInteger(byte[] pArray) {
707 return new BigInteger(1, decodeBase64(pArray));
708 }
709
710 /**
711 * Encodes to a byte64-encoded integer according to crypto standards such as W3C's XML-Signature
712 *
713 * @param bigInt
714 * a BigInteger
715 * @return A byte array containing base64 character data
716 * @throws NullPointerException
717 * if null is passed in
718 * @since 1.4
719 */
720 public static byte[] encodeInteger(BigInteger bigInt) {
721 if (bigInt == null) {
722 throw new NullPointerException("encodeInteger called with null parameter");
723 }
724 return encodeBase64(toIntegerBytes(bigInt), false);
725 }
726
727 /**
728 * Returns a byte-array representation of a <code>BigInteger</code> without sign bit.
729 *
730 * @param bigInt
731 * <code>BigInteger</code> to be converted
732 * @return a byte array representation of the BigInteger parameter
733 */
734 static byte[] toIntegerBytes(BigInteger bigInt) {
735 int bitlen = bigInt.bitLength();
736 // round bitlen
737 bitlen = ((bitlen + 7) >> 3) << 3;
738 byte[] bigBytes = bigInt.toByteArray();
739
740 if (((bigInt.bitLength() % 8) != 0) && (((bigInt.bitLength() / 8) + 1) == (bitlen / 8))) {
741 return bigBytes;
742 }
743 // set up params for copying everything but sign bit
744 int startSrc = 0;
745 int len = bigBytes.length;
746
747 // if bigInt is exactly byte-aligned, just skip signbit in copy
748 if ((bigInt.bitLength() % 8) == 0) {
749 startSrc = 1;
750 len--;
751 }
752 int startDst = bitlen / 8 - len; // to pad w/ nulls as per spec
753 byte[] resizedBytes = new byte[bitlen / 8];
754 System.arraycopy(bigBytes, startSrc, resizedBytes, startDst, len);
755 return resizedBytes;
756 }
757
758 /**
759 * Returns whether or not the <code>octet</code> is in the Base32 alphabet.
760 *
761 * @param octet
762 * The value to test
763 * @return {@code true} if the value is defined in the the Base32 alphabet {@code false} otherwise.
764 */
765 @Override
766 protected boolean isInAlphabet(byte octet) {
767 return octet >= 0 && octet < decodeTable.length && decodeTable[octet] != -1;
768 }
769
770 }