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 encode/decode
40 * character encodings which are compatible with the lower 127 ASCII chart (ISO-8859-1, Windows-1252, UTF-8, etc).
41 * </p>
42 * <p>
43 * This class is not thread-safe. Each thread should use its own instance.
44 * </p>
45 *
46 * @see <a href="http://www.ietf.org/rfc/rfc2045.txt">RFC 2045</a>
47 * @author Apache Software Foundation
48 * @since 1.0
49 * @version $Revision: 1201529 $
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 in
103 * 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 * Place holder for the bytes we're dealing with for our based logic.
161 * Bitwise operations store and extract the encoding or decoding from this variable.
162 */
163 private int bitWorkArea;
164
165 /**
166 * Creates a Base64 codec used for decoding (all modes) and encoding in URL-unsafe mode.
167 * <p>
168 * When encoding the line length is 0 (no chunking), and the encoding table is STANDARD_ENCODE_TABLE.
169 * </p>
170 *
171 * <p>
172 * When decoding all variants are supported.
173 * </p>
174 */
175 public Base64() {
176 this(0);
177 }
178
179 /**
180 * Creates a Base64 codec used for decoding (all modes) and encoding in the given URL-safe mode.
181 * <p>
182 * When encoding the line length is 76, the line separator is CRLF, and the encoding table is STANDARD_ENCODE_TABLE.
183 * </p>
184 *
185 * <p>
186 * When decoding all variants are supported.
187 * </p>
188 *
189 * @param urlSafe
190 * if <code>true</code>, URL-safe encoding is used. In most cases this should be set to
191 * <code>false</code>.
192 * @since 1.4
193 */
194 public Base64(boolean urlSafe) {
195 this(MIME_CHUNK_SIZE, CHUNK_SEPARATOR, urlSafe);
196 }
197
198 /**
199 * Creates a Base64 codec used for decoding (all modes) and encoding in URL-unsafe mode.
200 * <p>
201 * When encoding the line length is given in the constructor, the line separator is CRLF, and the encoding table is
202 * STANDARD_ENCODE_TABLE.
203 * </p>
204 * <p>
205 * Line lengths that aren't multiples of 4 will still essentially end up being multiples of 4 in the encoded data.
206 * </p>
207 * <p>
208 * When decoding all variants are supported.
209 * </p>
210 *
211 * @param lineLength
212 * Each line of encoded data will be at most of the given length (rounded down to nearest multiple of 4).
213 * If lineLength <= 0, then the output will not be divided into lines (chunks). Ignored when decoding.
214 * @since 1.4
215 */
216 public Base64(int lineLength) {
217 this(lineLength, CHUNK_SEPARATOR);
218 }
219
220 /**
221 * Creates a Base64 codec used for decoding (all modes) and encoding in URL-unsafe mode.
222 * <p>
223 * When encoding the line length and line separator are given in the constructor, and the encoding table is
224 * STANDARD_ENCODE_TABLE.
225 * </p>
226 * <p>
227 * Line lengths that aren't multiples of 4 will still essentially end up being multiples of 4 in the encoded data.
228 * </p>
229 * <p>
230 * When decoding all variants are supported.
231 * </p>
232 *
233 * @param lineLength
234 * Each line of encoded data will be at most of the given length (rounded down to nearest multiple of 4).
235 * If lineLength <= 0, then the output will not be divided into lines (chunks). Ignored when decoding.
236 * @param lineSeparator
237 * Each line of encoded data will end with this sequence of bytes.
238 * @throws IllegalArgumentException
239 * Thrown when the provided lineSeparator included some base64 characters.
240 * @since 1.4
241 */
242 public Base64(int lineLength, byte[] lineSeparator) {
243 this(lineLength, lineSeparator, false);
244 }
245
246 /**
247 * Creates a Base64 codec used for decoding (all modes) and encoding in URL-unsafe mode.
248 * <p>
249 * When encoding the line length and line separator are given in the constructor, and the encoding table is
250 * STANDARD_ENCODE_TABLE.
251 * </p>
252 * <p>
253 * Line lengths that aren't multiples of 4 will still essentially end up being multiples of 4 in the encoded data.
254 * </p>
255 * <p>
256 * When decoding all variants are supported.
257 * </p>
258 *
259 * @param lineLength
260 * Each line of encoded data will be at most of the given length (rounded down to nearest multiple of 4).
261 * If lineLength <= 0, then the output will not be divided into lines (chunks). Ignored when decoding.
262 * @param lineSeparator
263 * Each line of encoded data will end with this sequence of bytes.
264 * @param urlSafe
265 * Instead of emitting '+' and '/' we emit '-' and '_' respectively. urlSafe is only applied to encode
266 * operations. Decoding seamlessly handles both modes.
267 * @throws IllegalArgumentException
268 * The provided lineSeparator included some base64 characters. That's not going to work!
269 * @since 1.4
270 */
271 public Base64(int lineLength, byte[] lineSeparator, boolean urlSafe) {
272 super(BYTES_PER_UNENCODED_BLOCK, BYTES_PER_ENCODED_BLOCK,
273 lineLength,
274 lineSeparator == null ? 0 : lineSeparator.length);
275 // TODO could be simplified if there is no requirement to reject invalid line sep when length <=0
276 // @see test case Base64Test.testConstructors()
277 if (lineSeparator != null) {
278 if (containsAlphabetOrPad(lineSeparator)) {
279 String sep = StringUtils.newStringUtf8(lineSeparator);
280 throw new IllegalArgumentException("lineSeparator must not contain base64 characters: [" + sep + "]");
281 }
282 if (lineLength > 0){ // null line-sep forces no chunking rather than throwing IAE
283 this.encodeSize = BYTES_PER_ENCODED_BLOCK + lineSeparator.length;
284 this.lineSeparator = new byte[lineSeparator.length];
285 System.arraycopy(lineSeparator, 0, this.lineSeparator, 0, lineSeparator.length);
286 } else {
287 this.encodeSize = BYTES_PER_ENCODED_BLOCK;
288 this.lineSeparator = null;
289 }
290 } else {
291 this.encodeSize = BYTES_PER_ENCODED_BLOCK;
292 this.lineSeparator = null;
293 }
294 this.decodeSize = this.encodeSize - 1;
295 this.encodeTable = urlSafe ? URL_SAFE_ENCODE_TABLE : STANDARD_ENCODE_TABLE;
296 }
297
298 /**
299 * Returns our current encode mode. True if we're URL-SAFE, false otherwise.
300 *
301 * @return true if we're in URL-SAFE mode, false otherwise.
302 * @since 1.4
303 */
304 public boolean isUrlSafe() {
305 return this.encodeTable == URL_SAFE_ENCODE_TABLE;
306 }
307
308 /**
309 * <p>
310 * Encodes all of the provided data, starting at inPos, for inAvail bytes. Must be called at least twice: once with
311 * the data to encode, and once with inAvail set to "-1" to alert encoder that EOF has been reached, so flush last
312 * remaining bytes (if not multiple of 3).
313 * </p>
314 * <p>
315 * Thanks to "commons" project in ws.apache.org for the bitwise operations, and general approach.
316 * http://svn.apache.org/repos/asf/webservices/commons/trunk/modules/util/
317 * </p>
318 *
319 * @param in
320 * byte[] array of binary data to base64 encode.
321 * @param inPos
322 * Position to start reading data from.
323 * @param inAvail
324 * Amount of bytes available from input for encoding.
325 */
326 @Override
327 void encode(byte[] in, int inPos, int inAvail) {
328 if (eof) {
329 return;
330 }
331 // inAvail < 0 is how we're informed of EOF in the underlying data we're
332 // encoding.
333 if (inAvail < 0) {
334 eof = true;
335 if (0 == modulus && lineLength == 0) {
336 return; // no leftovers to process and not using chunking
337 }
338 ensureBufferSize(encodeSize);
339 int savedPos = pos;
340 switch (modulus) { // 0-2
341 case 1 : // 8 bits = 6 + 2
342 buffer[pos++] = encodeTable[(bitWorkArea >> 2) & MASK_6BITS]; // top 6 bits
343 buffer[pos++] = encodeTable[(bitWorkArea << 4) & MASK_6BITS]; // remaining 2
344 // URL-SAFE skips the padding to further reduce size.
345 if (encodeTable == STANDARD_ENCODE_TABLE) {
346 buffer[pos++] = PAD;
347 buffer[pos++] = PAD;
348 }
349 break;
350
351 case 2 : // 16 bits = 6 + 6 + 4
352 buffer[pos++] = encodeTable[(bitWorkArea >> 10) & MASK_6BITS];
353 buffer[pos++] = encodeTable[(bitWorkArea >> 4) & MASK_6BITS];
354 buffer[pos++] = encodeTable[(bitWorkArea << 2) & MASK_6BITS];
355 // URL-SAFE skips the padding to further reduce size.
356 if (encodeTable == STANDARD_ENCODE_TABLE) {
357 buffer[pos++] = PAD;
358 }
359 break;
360 }
361 currentLinePos += pos - savedPos; // keep track of current line position
362 // if currentPos == 0 we are at the start of a line, so don't add CRLF
363 if (lineLength > 0 && currentLinePos > 0) {
364 System.arraycopy(lineSeparator, 0, buffer, pos, lineSeparator.length);
365 pos += lineSeparator.length;
366 }
367 } else {
368 for (int i = 0; i < inAvail; i++) {
369 ensureBufferSize(encodeSize);
370 modulus = (modulus+1) % BYTES_PER_UNENCODED_BLOCK;
371 int b = in[inPos++];
372 if (b < 0) {
373 b += 256;
374 }
375 bitWorkArea = (bitWorkArea << 8) + b; // BITS_PER_BYTE
376 if (0 == modulus) { // 3 bytes = 24 bits = 4 * 6 bits to extract
377 buffer[pos++] = encodeTable[(bitWorkArea >> 18) & MASK_6BITS];
378 buffer[pos++] = encodeTable[(bitWorkArea >> 12) & MASK_6BITS];
379 buffer[pos++] = encodeTable[(bitWorkArea >> 6) & MASK_6BITS];
380 buffer[pos++] = encodeTable[bitWorkArea & MASK_6BITS];
381 currentLinePos += BYTES_PER_ENCODED_BLOCK;
382 if (lineLength > 0 && lineLength <= currentLinePos) {
383 System.arraycopy(lineSeparator, 0, buffer, pos, lineSeparator.length);
384 pos += lineSeparator.length;
385 currentLinePos = 0;
386 }
387 }
388 }
389 }
390 }
391
392 /**
393 * <p>
394 * Decodes all of the provided data, starting at inPos, for inAvail bytes. Should be called at least twice: once
395 * with the data to decode, and once with inAvail set to "-1" to alert decoder that EOF has been reached. The "-1"
396 * call is not necessary when decoding, but it doesn't hurt, either.
397 * </p>
398 * <p>
399 * Ignores all non-base64 characters. This is how chunked (e.g. 76 character) data is handled, since CR and LF are
400 * silently ignored, but has implications for other bytes, too. This method subscribes to the garbage-in,
401 * garbage-out philosophy: it will not check the provided data for validity.
402 * </p>
403 * <p>
404 * Thanks to "commons" project in ws.apache.org for the bitwise operations, and general approach.
405 * http://svn.apache.org/repos/asf/webservices/commons/trunk/modules/util/
406 * </p>
407 *
408 * @param in
409 * byte[] array of ascii data to base64 decode.
410 * @param inPos
411 * Position to start reading data from.
412 * @param inAvail
413 * Amount of bytes available from input for encoding.
414 */
415 @Override
416 void decode(byte[] in, int inPos, int inAvail) {
417 if (eof) {
418 return;
419 }
420 if (inAvail < 0) {
421 eof = true;
422 }
423 for (int i = 0; i < inAvail; i++) {
424 ensureBufferSize(decodeSize);
425 byte b = in[inPos++];
426 if (b == PAD) {
427 // We're done.
428 eof = true;
429 break;
430 } else {
431 if (b >= 0 && b < DECODE_TABLE.length) {
432 int result = DECODE_TABLE[b];
433 if (result >= 0) {
434 modulus = (modulus+1) % BYTES_PER_ENCODED_BLOCK;
435 bitWorkArea = (bitWorkArea << BITS_PER_ENCODED_BYTE) + result;
436 if (modulus == 0) {
437 buffer[pos++] = (byte) ((bitWorkArea >> 16) & MASK_8BITS);
438 buffer[pos++] = (byte) ((bitWorkArea >> 8) & MASK_8BITS);
439 buffer[pos++] = (byte) (bitWorkArea & MASK_8BITS);
440 }
441 }
442 }
443 }
444 }
445
446 // Two forms of EOF as far as base64 decoder is concerned: actual
447 // EOF (-1) and first time '=' character is encountered in stream.
448 // This approach makes the '=' padding characters completely optional.
449 if (eof && modulus != 0) {
450 ensureBufferSize(decodeSize);
451
452 // We have some spare bits remaining
453 // Output all whole multiples of 8 bits and ignore the rest
454 switch (modulus) {
455 // case 1: // 6 bits - ignore entirely
456 // break;
457 case 2 : // 12 bits = 8 + 4
458 bitWorkArea = bitWorkArea >> 4; // dump the extra 4 bits
459 buffer[pos++] = (byte) ((bitWorkArea) & MASK_8BITS);
460 break;
461 case 3 : // 18 bits = 8 + 8 + 2
462 bitWorkArea = bitWorkArea >> 2; // dump 2 bits
463 buffer[pos++] = (byte) ((bitWorkArea >> 8) & MASK_8BITS);
464 buffer[pos++] = (byte) ((bitWorkArea) & MASK_8BITS);
465 break;
466 }
467 }
468 }
469
470 /**
471 * Tests a given byte array to see if it contains only valid characters within the Base64 alphabet. Currently the
472 * method treats whitespace as valid.
473 *
474 * @param arrayOctet
475 * byte array to test
476 * @return <code>true</code> if all bytes are valid characters in the Base64 alphabet or if the byte array is empty;
477 * <code>false</code>, otherwise
478 * @deprecated 1.5 Use {@link #isBase64(byte[])}, will be removed in 2.0.
479 */
480 public static boolean isArrayByteBase64(byte[] arrayOctet) {
481 return isBase64(arrayOctet);
482 }
483
484 /**
485 * Returns whether or not the <code>octet</code> is in the base 64 alphabet.
486 *
487 * @param octet
488 * The value to test
489 * @return <code>true</code> if the value is defined in the the base 64 alphabet, <code>false</code> otherwise.
490 * @since 1.4
491 */
492 public static boolean isBase64(byte octet) {
493 return octet == PAD_DEFAULT || (octet >= 0 && octet < DECODE_TABLE.length && DECODE_TABLE[octet] != -1);
494 }
495
496 /**
497 * Tests a given String to see if it contains only valid characters within the Base64 alphabet. Currently the
498 * method treats whitespace as valid.
499 *
500 * @param base64
501 * String to test
502 * @return <code>true</code> if all characters in the String are valid characters in the Base64 alphabet or if
503 * the String is empty; <code>false</code>, otherwise
504 * @since 1.5
505 */
506 public static boolean isBase64(String base64) {
507 return isBase64(StringUtils.getBytesUtf8(base64));
508 }
509
510 /**
511 * Tests a given byte array to see if it contains only valid characters within the Base64 alphabet. Currently the
512 * method treats whitespace as valid.
513 *
514 * @param arrayOctet
515 * byte array to test
516 * @return <code>true</code> if all bytes are valid characters in the Base64 alphabet or if the byte array is empty;
517 * <code>false</code>, otherwise
518 * @since 1.5
519 */
520 public static boolean isBase64(byte[] arrayOctet) {
521 for (int i = 0; i < arrayOctet.length; i++) {
522 if (!isBase64(arrayOctet[i]) && !isWhiteSpace(arrayOctet[i])) {
523 return false;
524 }
525 }
526 return true;
527 }
528
529 /**
530 * Encodes binary data using the base64 algorithm but does not chunk the output.
531 *
532 * @param binaryData
533 * binary data to encode
534 * @return byte[] containing Base64 characters in their UTF-8 representation.
535 */
536 public static byte[] encodeBase64(byte[] binaryData) {
537 return encodeBase64(binaryData, false);
538 }
539
540 /**
541 * Encodes binary data using the base64 algorithm but does not chunk the output.
542 *
543 * NOTE: We changed the behaviour of this method from multi-line chunking (commons-codec-1.4) to
544 * single-line non-chunking (commons-codec-1.5).
545 *
546 * @param binaryData
547 * binary data to encode
548 * @return String containing Base64 characters.
549 * @since 1.4 (NOTE: 1.4 chunked the output, whereas 1.5 does not).
550 */
551 public static String encodeBase64String(byte[] binaryData) {
552 return StringUtils.newStringUtf8(encodeBase64(binaryData, false));
553 }
554
555 /**
556 * Encodes binary data using a URL-safe variation of the base64 algorithm but does not chunk the output. The
557 * url-safe variation emits - and _ instead of + and / characters.
558 *
559 * @param binaryData
560 * binary data to encode
561 * @return byte[] containing Base64 characters in their UTF-8 representation.
562 * @since 1.4
563 */
564 public static byte[] encodeBase64URLSafe(byte[] binaryData) {
565 return encodeBase64(binaryData, false, true);
566 }
567
568 /**
569 * Encodes binary data using a URL-safe variation of the base64 algorithm but does not chunk the output. The
570 * url-safe variation emits - and _ instead of + and / characters.
571 *
572 * @param binaryData
573 * binary data to encode
574 * @return String containing Base64 characters
575 * @since 1.4
576 */
577 public static String encodeBase64URLSafeString(byte[] binaryData) {
578 return StringUtils.newStringUtf8(encodeBase64(binaryData, false, true));
579 }
580
581 /**
582 * Encodes binary data using the base64 algorithm and chunks the encoded output into 76 character blocks
583 *
584 * @param binaryData
585 * binary data to encode
586 * @return Base64 characters chunked in 76 character blocks
587 */
588 public static byte[] encodeBase64Chunked(byte[] binaryData) {
589 return encodeBase64(binaryData, true);
590 }
591
592 /**
593 * Encodes binary data using the base64 algorithm, optionally chunking the output into 76 character blocks.
594 *
595 * @param binaryData
596 * Array containing binary data to encode.
597 * @param isChunked
598 * if <code>true</code> this encoder will chunk the base64 output into 76 character blocks
599 * @return Base64-encoded data.
600 * @throws IllegalArgumentException
601 * Thrown when the input array needs an output array bigger than {@link Integer#MAX_VALUE}
602 */
603 public static byte[] encodeBase64(byte[] binaryData, boolean isChunked) {
604 return encodeBase64(binaryData, isChunked, false);
605 }
606
607 /**
608 * Encodes binary data using the base64 algorithm, optionally chunking the output into 76 character blocks.
609 *
610 * @param binaryData
611 * Array containing binary data to encode.
612 * @param isChunked
613 * if <code>true</code> this encoder will chunk the base64 output into 76 character blocks
614 * @param urlSafe
615 * if <code>true</code> this encoder will emit - and _ instead of the usual + and / characters.
616 * @return Base64-encoded data.
617 * @throws IllegalArgumentException
618 * Thrown when the input array needs an output array bigger than {@link Integer#MAX_VALUE}
619 * @since 1.4
620 */
621 public static byte[] encodeBase64(byte[] binaryData, boolean isChunked, boolean urlSafe) {
622 return encodeBase64(binaryData, isChunked, urlSafe, Integer.MAX_VALUE);
623 }
624
625 /**
626 * Encodes binary data using the base64 algorithm, optionally chunking the output into 76 character blocks.
627 *
628 * @param binaryData
629 * Array containing binary data to encode.
630 * @param isChunked
631 * if <code>true</code> this encoder will chunk the base64 output into 76 character blocks
632 * @param urlSafe
633 * if <code>true</code> this encoder will emit - and _ instead of the usual + and / characters.
634 * @param maxResultSize
635 * The maximum result size to accept.
636 * @return Base64-encoded data.
637 * @throws IllegalArgumentException
638 * Thrown when the input array needs an output array bigger than maxResultSize
639 * @since 1.4
640 */
641 public static byte[] encodeBase64(byte[] binaryData, boolean isChunked, boolean urlSafe, int maxResultSize) {
642 if (binaryData == null || binaryData.length == 0) {
643 return binaryData;
644 }
645
646 // Create this so can use the super-class method
647 // Also ensures that the same roundings are performed by the ctor and the code
648 Base64 b64 = isChunked ? new Base64(urlSafe) : new Base64(0, CHUNK_SEPARATOR, urlSafe);
649 long len = b64.getEncodedLength(binaryData);
650 if (len > maxResultSize) {
651 throw new IllegalArgumentException("Input array too big, the output array would be bigger (" +
652 len +
653 ") than the specified maximum size of " +
654 maxResultSize);
655 }
656
657 return b64.encode(binaryData);
658 }
659
660 /**
661 * Decodes a Base64 String into octets
662 *
663 * @param base64String
664 * String containing Base64 data
665 * @return Array containing decoded data.
666 * @since 1.4
667 */
668 public static byte[] decodeBase64(String base64String) {
669 return new Base64().decode(base64String);
670 }
671
672 /**
673 * Decodes Base64 data into octets
674 *
675 * @param base64Data
676 * Byte array containing Base64 data
677 * @return Array containing decoded data.
678 */
679 public static byte[] decodeBase64(byte[] base64Data) {
680 return new Base64().decode(base64Data);
681 }
682
683 // Implementation of the Encoder Interface
684
685 // Implementation of integer encoding used for crypto
686 /**
687 * Decodes a byte64-encoded integer according to crypto standards such as W3C's XML-Signature
688 *
689 * @param pArray
690 * a byte array containing base64 character data
691 * @return A BigInteger
692 * @since 1.4
693 */
694 public static BigInteger decodeInteger(byte[] pArray) {
695 return new BigInteger(1, decodeBase64(pArray));
696 }
697
698 /**
699 * Encodes to a byte64-encoded integer according to crypto standards such as W3C's XML-Signature
700 *
701 * @param bigInt
702 * a BigInteger
703 * @return A byte array containing base64 character data
704 * @throws NullPointerException
705 * if null is passed in
706 * @since 1.4
707 */
708 public static byte[] encodeInteger(BigInteger bigInt) {
709 if (bigInt == null) {
710 throw new NullPointerException("encodeInteger called with null parameter");
711 }
712 return encodeBase64(toIntegerBytes(bigInt), false);
713 }
714
715 /**
716 * Returns a byte-array representation of a <code>BigInteger</code> without sign bit.
717 *
718 * @param bigInt
719 * <code>BigInteger</code> to be converted
720 * @return a byte array representation of the BigInteger parameter
721 */
722 static byte[] toIntegerBytes(BigInteger bigInt) {
723 int bitlen = bigInt.bitLength();
724 // round bitlen
725 bitlen = ((bitlen + 7) >> 3) << 3;
726 byte[] bigBytes = bigInt.toByteArray();
727
728 if (((bigInt.bitLength() % 8) != 0) && (((bigInt.bitLength() / 8) + 1) == (bitlen / 8))) {
729 return bigBytes;
730 }
731 // set up params for copying everything but sign bit
732 int startSrc = 0;
733 int len = bigBytes.length;
734
735 // if bigInt is exactly byte-aligned, just skip signbit in copy
736 if ((bigInt.bitLength() % 8) == 0) {
737 startSrc = 1;
738 len--;
739 }
740 int startDst = bitlen / 8 - len; // to pad w/ nulls as per spec
741 byte[] resizedBytes = new byte[bitlen / 8];
742 System.arraycopy(bigBytes, startSrc, resizedBytes, startDst, len);
743 return resizedBytes;
744 }
745
746 /**
747 * Returns whether or not the <code>octet</code> is in the Base32 alphabet.
748 *
749 * @param octet
750 * The value to test
751 * @return <code>true</code> if the value is defined in the the Base32 alphabet <code>false</code> otherwise.
752 */
753 @Override
754 protected boolean isInAlphabet(byte octet) {
755 return octet >= 0 && octet < decodeTable.length && decodeTable[octet] != -1;
756 }
757
758 }