1 package org.codehaus.plexus.util;
2
3 /*
4 * Copyright The Codehaus Foundation.
5 *
6 * Licensed under the Apache License, Version 2.0 (the "License");
7 * you may not use this file except in compliance with the License.
8 * You may obtain a copy of the License at
9 *
10 * http://www.apache.org/licenses/LICENSE-2.0
11 *
12 * Unless required by applicable law or agreed to in writing, software
13 * distributed under the License is distributed on an "AS IS" BASIS,
14 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
15 * See the License for the specific language governing permissions and
16 * limitations under the License.
17 */
18
19 /**
20 * Provides Base64 encoding and decoding as defined by RFC 2045.
21 * <p>
22 * This class implements section <cite>6.8. Base64 Content-Transfer-Encoding</cite> from RFC 2045 <cite>Multipurpose
23 * Internet Mail Extensions (MIME) Part One: Format of Internet Message Bodies</cite> by Freed and Borenstein.
24 * </p>
25 *
26 * @see <a href="http://www.ietf.org/rfc/rfc2045.txt">RFC 2045</a>
27 * @author Apache Software Foundation
28 * @since 1.0-dev
29 *
30 */
31 @Deprecated
32 public class Base64 {
33
34 //
35 // Source Id: Base64.java 161350 2005-04-14 20:39:46Z ggregory
36 //
37
38 /**
39 * Chunk size per RFC 2045 section 6.8.
40 * <p>
41 * The {@value} character limit does not count the trailing CRLF, but counts all other characters, including any
42 * equal signs.
43 * </p>
44 *
45 * @see <a href="http://www.ietf.org/rfc/rfc2045.txt">RFC 2045 section 6.8</a>
46 */
47 static final int CHUNK_SIZE = 76;
48
49 /**
50 * Chunk separator per RFC 2045 section 2.1.
51 *
52 * @see <a href="http://www.ietf.org/rfc/rfc2045.txt">RFC 2045 section 2.1</a>
53 */
54 static final byte[] CHUNK_SEPARATOR = "\r\n".getBytes();
55
56 /**
57 * The base length.
58 */
59 static final int BASELENGTH = 255;
60
61 /**
62 * Lookup length.
63 */
64 static final int LOOKUPLENGTH = 64;
65
66 /**
67 * Used to calculate the number of bits in a byte.
68 */
69 static final int EIGHTBIT = 8;
70
71 /**
72 * Used when encoding something which has fewer than 24 bits.
73 */
74 static final int SIXTEENBIT = 16;
75
76 /**
77 * Used to determine how many bits data contains.
78 */
79 static final int TWENTYFOURBITGROUP = 24;
80
81 /**
82 * Used to get the number of Quadruples.
83 */
84 static final int FOURBYTE = 4;
85
86 /**
87 * Used to test the sign of a byte.
88 */
89 static final int SIGN = -128;
90
91 /**
92 * Byte used to pad output.
93 */
94 static final byte PAD = (byte) '=';
95
96 /**
97 * Contains the Base64 values <code>0</code> through <code>63</code> accessed by using character encodings as
98 * indices.
99 * <p>
100 * For example, <code>base64Alphabet['+']</code> returns <code>62</code>.
101 * </p>
102 * <p>
103 * The value of undefined encodings is <code>-1</code>.
104 * </p>
105 */
106 private static byte[] base64Alphabet = new byte[BASELENGTH];
107
108 /**
109 * <p>
110 * Contains the Base64 encodings <code>A</code> through <code>Z</code>, followed by <code>a</code> through
111 * <code>z</code>, followed by <code>0</code> through <code>9</code>, followed by <code>+</code>, and
112 * <code>/</code>.
113 * </p>
114 * <p>
115 * This array is accessed by using character values as indices.
116 * </p>
117 * <p>
118 * For example, <code>lookUpBase64Alphabet[62] </code> returns <code>'+'</code>.
119 * </p>
120 */
121 private static byte[] lookUpBase64Alphabet = new byte[LOOKUPLENGTH];
122
123 // Populating the lookup and character arrays
124 static {
125 for (int i = 0; i < BASELENGTH; i++) {
126 base64Alphabet[i] = (byte) -1;
127 }
128 for (int i = 'Z'; i >= 'A'; i--) {
129 base64Alphabet[i] = (byte) (i - 'A');
130 }
131 for (int i = 'z'; i >= 'a'; i--) {
132 base64Alphabet[i] = (byte) (i - 'a' + 26);
133 }
134 for (int i = '9'; i >= '0'; i--) {
135 base64Alphabet[i] = (byte) (i - '0' + 52);
136 }
137
138 base64Alphabet['+'] = 62;
139 base64Alphabet['/'] = 63;
140
141 for (int i = 0; i <= 25; i++) {
142 lookUpBase64Alphabet[i] = (byte) ('A' + i);
143 }
144
145 for (int i = 26, j = 0; i <= 51; i++, j++) {
146 lookUpBase64Alphabet[i] = (byte) ('a' + j);
147 }
148
149 for (int i = 52, j = 0; i <= 61; i++, j++) {
150 lookUpBase64Alphabet[i] = (byte) ('0' + j);
151 }
152
153 lookUpBase64Alphabet[62] = (byte) '+';
154 lookUpBase64Alphabet[63] = (byte) '/';
155 }
156
157 /**
158 * Returns whether or not the <code>octect</code> is in the base 64 alphabet.
159 *
160 * @param octect The value to test
161 * @return <code>true</code> if the value is defined in the the base 64 alphabet, <code>false</code> otherwise.
162 */
163 private static boolean isBase64(byte octect) {
164 if (octect == PAD) {
165 return true;
166 } else if (octect < 0 || base64Alphabet[octect] == -1) {
167 return false;
168 } else {
169 return true;
170 }
171 }
172
173 /**
174 * Tests a given byte array to see if it contains only valid characters within the Base64 alphabet.
175 *
176 * @param arrayOctect byte array to test
177 * @return <code>true</code> if all bytes are valid characters in the Base64 alphabet or if the byte array is empty;
178 * false, otherwise
179 */
180 public static boolean isArrayByteBase64(byte[] arrayOctect) {
181
182 arrayOctect = discardWhitespace(arrayOctect);
183
184 int length = arrayOctect.length;
185 if (length == 0) {
186 // shouldn't a 0 length array be valid base64 data?
187 // return false;
188 return true;
189 }
190 for (byte anArrayOctect : arrayOctect) {
191 if (!isBase64(anArrayOctect)) {
192 return false;
193 }
194 }
195 return true;
196 }
197
198 /**
199 * Encodes binary data using the base64 algorithm but does not chunk the output.
200 *
201 * @param binaryData binary data to encode
202 * @return Base64 characters
203 */
204 public static byte[] encodeBase64(byte[] binaryData) {
205 return encodeBase64(binaryData, false);
206 }
207
208 /**
209 * Encodes binary data using the base64 algorithm and chunks the encoded output into 76 character blocks
210 *
211 * @param binaryData binary data to encode
212 * @return Base64 characters chunked in 76 character blocks
213 */
214 public static byte[] encodeBase64Chunked(byte[] binaryData) {
215 return encodeBase64(binaryData, true);
216 }
217
218 /**
219 * Decodes a byte[] containing containing characters in the Base64 alphabet.
220 *
221 * @param pArray A byte array containing Base64 character data
222 * @return a byte array containing binary data
223 */
224 public byte[] decode(byte[] pArray) {
225 return decodeBase64(pArray);
226 }
227
228 /**
229 * Encodes binary data using the base64 algorithm, optionally chunking the output into 76 character blocks.
230 *
231 * @param binaryData Array containing binary data to encode.
232 * @param isChunked if <code>true</code> this encoder will chunk the base64 output into 76 character blocks
233 * @return Base64-encoded data.
234 */
235 public static byte[] encodeBase64(byte[] binaryData, boolean isChunked) {
236 int lengthDataBits = binaryData.length * EIGHTBIT;
237 int fewerThan24bits = lengthDataBits % TWENTYFOURBITGROUP;
238 int numberTriplets = lengthDataBits / TWENTYFOURBITGROUP;
239 byte encodedData[] = null;
240 int encodedDataLength = 0;
241 int nbrChunks = 0;
242
243 if (fewerThan24bits != 0) {
244 // data not divisible by 24 bit
245 encodedDataLength = (numberTriplets + 1) * 4;
246 } else {
247 // 16 or 8 bit
248 encodedDataLength = numberTriplets * 4;
249 }
250
251 // If the output is to be "chunked" into 76 character sections,
252 // for compliance with RFC 2045 MIME, then it is important to
253 // allow for extra length to account for the separator(s)
254 if (isChunked) {
255
256 nbrChunks = (CHUNK_SEPARATOR.length == 0 ? 0 : (int) Math.ceil((float) encodedDataLength / CHUNK_SIZE));
257 encodedDataLength += nbrChunks * CHUNK_SEPARATOR.length;
258 }
259
260 encodedData = new byte[encodedDataLength];
261
262 byte k = 0, l = 0, b1 = 0, b2 = 0, b3 = 0;
263
264 int encodedIndex = 0;
265 int dataIndex = 0;
266 int i = 0;
267 int nextSeparatorIndex = CHUNK_SIZE;
268 int chunksSoFar = 0;
269
270 // log.debug("number of triplets = " + numberTriplets);
271 for (i = 0; i < numberTriplets; i++) {
272 dataIndex = i * 3;
273 b1 = binaryData[dataIndex];
274 b2 = binaryData[dataIndex + 1];
275 b3 = binaryData[dataIndex + 2];
276
277 // log.debug("b1= " + b1 +", b2= " + b2 + ", b3= " + b3);
278
279 l = (byte) (b2 & 0x0f);
280 k = (byte) (b1 & 0x03);
281
282 byte val1 = ((b1 & SIGN) == 0) ? (byte) (b1 >> 2) : (byte) ((b1) >> 2 ^ 0xc0);
283 byte val2 = ((b2 & SIGN) == 0) ? (byte) (b2 >> 4) : (byte) ((b2) >> 4 ^ 0xf0);
284 byte val3 = ((b3 & SIGN) == 0) ? (byte) (b3 >> 6) : (byte) ((b3) >> 6 ^ 0xfc);
285
286 encodedData[encodedIndex] = lookUpBase64Alphabet[val1];
287 encodedData[encodedIndex + 1] = lookUpBase64Alphabet[val2 | (k << 4)];
288 encodedData[encodedIndex + 2] = lookUpBase64Alphabet[(l << 2) | val3];
289 encodedData[encodedIndex + 3] = lookUpBase64Alphabet[b3 & 0x3f];
290
291 encodedIndex += 4;
292
293 // If we are chunking, let's put a chunk separator down.
294 if (isChunked) {
295 // this assumes that CHUNK_SIZE % 4 == 0
296 if (encodedIndex == nextSeparatorIndex) {
297 System.arraycopy(CHUNK_SEPARATOR, 0, encodedData, encodedIndex, CHUNK_SEPARATOR.length);
298 chunksSoFar++;
299 nextSeparatorIndex = (CHUNK_SIZE * (chunksSoFar + 1)) + (chunksSoFar * CHUNK_SEPARATOR.length);
300 encodedIndex += CHUNK_SEPARATOR.length;
301 }
302 }
303 }
304
305 // form integral number of 6-bit groups
306 dataIndex = i * 3;
307
308 if (fewerThan24bits == EIGHTBIT) {
309 b1 = binaryData[dataIndex];
310 k = (byte) (b1 & 0x03);
311 byte val1 = ((b1 & SIGN) == 0) ? (byte) (b1 >> 2) : (byte) ((b1) >> 2 ^ 0xc0);
312 encodedData[encodedIndex] = lookUpBase64Alphabet[val1];
313 encodedData[encodedIndex + 1] = lookUpBase64Alphabet[k << 4];
314 encodedData[encodedIndex + 2] = PAD;
315 encodedData[encodedIndex + 3] = PAD;
316 } else if (fewerThan24bits == SIXTEENBIT) {
317
318 b1 = binaryData[dataIndex];
319 b2 = binaryData[dataIndex + 1];
320 l = (byte) (b2 & 0x0f);
321 k = (byte) (b1 & 0x03);
322
323 byte val1 = ((b1 & SIGN) == 0) ? (byte) (b1 >> 2) : (byte) ((b1) >> 2 ^ 0xc0);
324 byte val2 = ((b2 & SIGN) == 0) ? (byte) (b2 >> 4) : (byte) ((b2) >> 4 ^ 0xf0);
325
326 encodedData[encodedIndex] = lookUpBase64Alphabet[val1];
327 encodedData[encodedIndex + 1] = lookUpBase64Alphabet[val2 | (k << 4)];
328 encodedData[encodedIndex + 2] = lookUpBase64Alphabet[l << 2];
329 encodedData[encodedIndex + 3] = PAD;
330 }
331
332 if (isChunked) {
333 // we also add a separator to the end of the final chunk.
334 if (chunksSoFar < nbrChunks) {
335 System.arraycopy(
336 CHUNK_SEPARATOR,
337 0,
338 encodedData,
339 encodedDataLength - CHUNK_SEPARATOR.length,
340 CHUNK_SEPARATOR.length);
341 }
342 }
343
344 return encodedData;
345 }
346
347 /**
348 * Decodes Base64 data into octects
349 *
350 * @param base64Data Byte array containing Base64 data
351 * @return Array containing decoded data.
352 */
353 public static byte[] decodeBase64(byte[] base64Data) {
354 // RFC 2045 requires that we discard ALL non-Base64 characters
355 base64Data = discardNonBase64(base64Data);
356
357 // handle the edge case, so we don't have to worry about it later
358 if (base64Data.length == 0) {
359 return new byte[0];
360 }
361
362 int numberQuadruple = base64Data.length / FOURBYTE;
363 byte decodedData[] = null;
364 byte b1 = 0, b2 = 0, b3 = 0, b4 = 0, marker0 = 0, marker1 = 0;
365
366 // Throw away anything not in base64Data
367
368 int encodedIndex = 0;
369 int dataIndex = 0;
370 {
371 // this sizes the output array properly - rlw
372 int lastData = base64Data.length;
373 // ignore the '=' padding
374 while (base64Data[lastData - 1] == PAD) {
375 if (--lastData == 0) {
376 return new byte[0];
377 }
378 }
379 decodedData = new byte[lastData - numberQuadruple];
380 }
381
382 for (int i = 0; i < numberQuadruple; i++) {
383 dataIndex = i * 4;
384 marker0 = base64Data[dataIndex + 2];
385 marker1 = base64Data[dataIndex + 3];
386
387 b1 = base64Alphabet[base64Data[dataIndex]];
388 b2 = base64Alphabet[base64Data[dataIndex + 1]];
389
390 if (marker0 != PAD && marker1 != PAD) {
391 // No PAD e.g 3cQl
392 b3 = base64Alphabet[marker0];
393 b4 = base64Alphabet[marker1];
394
395 decodedData[encodedIndex] = (byte) (b1 << 2 | b2 >> 4);
396 decodedData[encodedIndex + 1] = (byte) (((b2 & 0xf) << 4) | ((b3 >> 2) & 0xf));
397 decodedData[encodedIndex + 2] = (byte) (b3 << 6 | b4);
398 } else if (marker0 == PAD) {
399 // Two PAD e.g. 3c[Pad][Pad]
400 decodedData[encodedIndex] = (byte) (b1 << 2 | b2 >> 4);
401 } else if (marker1 == PAD) {
402 // One PAD e.g. 3cQ[Pad]
403 b3 = base64Alphabet[marker0];
404
405 decodedData[encodedIndex] = (byte) (b1 << 2 | b2 >> 4);
406 decodedData[encodedIndex + 1] = (byte) (((b2 & 0xf) << 4) | ((b3 >> 2) & 0xf));
407 }
408 encodedIndex += 3;
409 }
410 return decodedData;
411 }
412
413 /**
414 * Discards any whitespace from a base-64 encoded block.
415 *
416 * @param data The base-64 encoded data to discard the whitespace from.
417 * @return The data, less whitespace (see RFC 2045).
418 */
419 static byte[] discardWhitespace(byte[] data) {
420 byte groomedData[] = new byte[data.length];
421 int bytesCopied = 0;
422
423 for (byte aData : data) {
424 switch (aData) {
425 case (byte) ' ':
426 case (byte) '\n':
427 case (byte) '\r':
428 case (byte) '\t':
429 break;
430 default:
431 groomedData[bytesCopied++] = aData;
432 }
433 }
434
435 byte packedData[] = new byte[bytesCopied];
436
437 System.arraycopy(groomedData, 0, packedData, 0, bytesCopied);
438
439 return packedData;
440 }
441
442 /**
443 * Discards any characters outside of the base64 alphabet, per the requirements on page 25 of RFC 2045 - "Any
444 * characters outside of the base64 alphabet are to be ignored in base64 encoded data."
445 *
446 * @param data The base-64 encoded data to groom
447 * @return The data, less non-base64 characters (see RFC 2045).
448 */
449 static byte[] discardNonBase64(byte[] data) {
450 byte groomedData[] = new byte[data.length];
451 int bytesCopied = 0;
452
453 for (byte aData : data) {
454 if (isBase64(aData)) {
455 groomedData[bytesCopied++] = aData;
456 }
457 }
458
459 byte packedData[] = new byte[bytesCopied];
460
461 System.arraycopy(groomedData, 0, packedData, 0, bytesCopied);
462
463 return packedData;
464 }
465
466 /**
467 * Encodes a byte[] containing binary data, into a byte[] containing characters in the Base64 alphabet.
468 *
469 * @param pArray a byte array containing binary data
470 * @return A byte array containing only Base64 character data
471 */
472 public byte[] encode(byte[] pArray) {
473 return encodeBase64(pArray, false);
474 }
475 }