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 /**
21 * Provides Base32 encoding and decoding as defined by <a href="http://www.ietf.org/rfc/rfc4648.txt">RFC 4648</a>.
22 *
23 * <p>
24 * The class can be parameterized in the following manner with various constructors:
25 * </p>
26 * <ul>
27 * <li>Whether to use the "base32hex" variant instead of the default "base32"</li>
28 * <li>Line length: Default 76. Line length that aren't multiples of 8 will still essentially end up being multiples of
29 * 8 in the encoded data.
30 * <li>Line separator: Default is CRLF ("\r\n")</li>
31 * </ul>
32 * <p>
33 * This class operates directly on byte streams, and not character streams.
34 * </p>
35 * <p>
36 * This class is thread-safe.
37 * </p>
38 *
39 * @see <a href="http://www.ietf.org/rfc/rfc4648.txt">RFC 4648</a>
40 *
41 * @since 1.5
42 * @version $Id: Base32.java 1809441 2017-09-23 16:41:53Z ggregory $
43 */
44 public class Base32 extends BaseNCodec {
45
46 /**
47 * BASE32 characters are 5 bits in length.
48 * They are formed by taking a block of five octets to form a 40-bit string,
49 * which is converted into eight BASE32 characters.
50 */
51 private static final int BITS_PER_ENCODED_BYTE = 5;
52 private static final int BYTES_PER_ENCODED_BLOCK = 8;
53 private static final int BYTES_PER_UNENCODED_BLOCK = 5;
54
55 /**
56 * Chunk separator per RFC 2045 section 2.1.
57 *
58 * @see <a href="http://www.ietf.org/rfc/rfc2045.txt">RFC 2045 section 2.1</a>
59 */
60 private static final byte[] CHUNK_SEPARATOR = {'\r', '\n'};
61
62 /**
63 * This array is a lookup table that translates Unicode characters drawn from the "Base32 Alphabet" (as specified
64 * in Table 3 of RFC 4648) into their 5-bit positive integer equivalents. Characters that are not in the Base32
65 * alphabet but fall within the bounds of the array are translated to -1.
66 */
67 private static final byte[] DECODE_TABLE = {
68 // 0 1 2 3 4 5 6 7 8 9 A B C D E F
69 -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, // 00-0f
70 -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, // 10-1f
71 -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, // 20-2f
72 -1, -1, 26, 27, 28, 29, 30, 31, -1, -1, -1, -1, -1, -1, -1, -1, // 30-3f 2-7
73 -1, 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, // 40-4f A-O
74 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, // 50-5a P-Z
75 -1, -1, -1, -1, -1, // 5b - 5f
76 -1, 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, // 60 - 6f a-o
77 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, // 70 - 7a p-z/**/
78 };
79
80 /**
81 * This array is a lookup table that translates 5-bit positive integer index values into their "Base32 Alphabet"
82 * equivalents as specified in Table 3 of RFC 4648.
83 */
84 private static final byte[] ENCODE_TABLE = {
85 'A', 'B', 'C', 'D', 'E', 'F', 'G', 'H', 'I', 'J', 'K', 'L', 'M',
86 'N', 'O', 'P', 'Q', 'R', 'S', 'T', 'U', 'V', 'W', 'X', 'Y', 'Z',
87 '2', '3', '4', '5', '6', '7',
88 };
89
90 /**
91 * This array is a lookup table that translates Unicode characters drawn from the "Base32 Hex Alphabet" (as
92 * specified in Table 4 of RFC 4648) into their 5-bit positive integer equivalents. Characters that are not in the
93 * Base32 Hex alphabet but fall within the bounds of the array are translated to -1.
94 */
95 private static final byte[] HEX_DECODE_TABLE = {
96 // 0 1 2 3 4 5 6 7 8 9 A B C D E F
97 -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, // 00-0f
98 -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, // 10-1f
99 -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, // 20-2f
100 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, -1, -1, -1, -1, -1, -1, // 30-3f 2-7
101 -1, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, // 40-4f A-O
102 25, 26, 27, 28, 29, 30, 31, // 50-56 P-V
103 -1, -1, -1, -1, -1, -1, -1, -1, -1, // 57-5f Z-_
104 -1, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, // 60-6f `-o
105 25, 26, 27, 28, 29, 30, 31 // 70-76 p-v
106 };
107
108 /**
109 * This array is a lookup table that translates 5-bit positive integer index values into their
110 * "Base32 Hex Alphabet" equivalents as specified in Table 4 of RFC 4648.
111 */
112 private static final byte[] HEX_ENCODE_TABLE = {
113 '0', '1', '2', '3', '4', '5', '6', '7', '8', '9',
114 'A', 'B', 'C', 'D', 'E', 'F', 'G', 'H', 'I', 'J', 'K', 'L', 'M',
115 'N', 'O', 'P', 'Q', 'R', 'S', 'T', 'U', 'V',
116 };
117
118 /** Mask used to extract 5 bits, used when encoding Base32 bytes */
119 private static final int MASK_5BITS = 0x1f;
120
121 // The static final fields above are used for the original static byte[] methods on Base32.
122 // The private member fields below are used with the new streaming approach, which requires
123 // some state be preserved between calls of encode() and decode().
124
125 /**
126 * Place holder for the bytes we're dealing with for our based logic.
127 * Bitwise operations store and extract the encoding or decoding from this variable.
128 */
129
130 /**
131 * Convenience variable to help us determine when our buffer is going to run out of room and needs resizing.
132 * <code>decodeSize = {@link #BYTES_PER_ENCODED_BLOCK} - 1 + lineSeparator.length;</code>
133 */
134 private final int decodeSize;
135
136 /**
137 * Decode table to use.
138 */
139 private final byte[] decodeTable;
140
141 /**
142 * Convenience variable to help us determine when our buffer is going to run out of room and needs resizing.
143 * <code>encodeSize = {@link #BYTES_PER_ENCODED_BLOCK} + lineSeparator.length;</code>
144 */
145 private final int encodeSize;
146
147 /**
148 * Encode table to use.
149 */
150 private final byte[] encodeTable;
151
152 /**
153 * Line separator for encoding. Not used when decoding. Only used if lineLength > 0.
154 */
155 private final byte[] lineSeparator;
156
157 /**
158 * Creates a Base32 codec used for decoding and encoding.
159 * <p>
160 * When encoding the line length is 0 (no chunking).
161 * </p>
162 *
163 */
164 public Base32() {
165 this(false);
166 }
167
168 /**
169 * Creates a Base32 codec used for decoding and encoding.
170 * <p>
171 * When encoding the line length is 0 (no chunking).
172 * </p>
173 * @param pad byte used as padding byte.
174 */
175 public Base32(final byte pad) {
176 this(false, pad);
177 }
178
179 /**
180 * Creates a Base32 codec used for decoding and encoding.
181 * <p>
182 * When encoding the line length is 0 (no chunking).
183 * </p>
184 * @param useHex if {@code true} then use Base32 Hex alphabet
185 */
186 public Base32(final boolean useHex) {
187 this(0, null, useHex, PAD_DEFAULT);
188 }
189
190 /**
191 * Creates a Base32 codec used for decoding and encoding.
192 * <p>
193 * When encoding the line length is 0 (no chunking).
194 * </p>
195 * @param useHex if {@code true} then use Base32 Hex alphabet
196 * @param pad byte used as padding byte.
197 */
198 public Base32(final boolean useHex, final byte pad) {
199 this(0, null, useHex, pad);
200 }
201
202 /**
203 * Creates a Base32 codec used for decoding and encoding.
204 * <p>
205 * When encoding the line length is given in the constructor, the line separator is CRLF.
206 * </p>
207 *
208 * @param lineLength
209 * Each line of encoded data will be at most of the given length (rounded down to nearest multiple of
210 * 8). If lineLength <= 0, then the output will not be divided into lines (chunks). Ignored when
211 * decoding.
212 */
213 public Base32(final int lineLength) {
214 this(lineLength, CHUNK_SEPARATOR);
215 }
216
217 /**
218 * Creates a Base32 codec used for decoding and encoding.
219 * <p>
220 * When encoding the line length and line separator are given in the constructor.
221 * </p>
222 * <p>
223 * Line lengths that aren't multiples of 8 will still essentially end up being multiples of 8 in the encoded data.
224 * </p>
225 *
226 * @param lineLength
227 * Each line of encoded data will be at most of the given length (rounded down to nearest multiple of
228 * 8). If lineLength <= 0, then the output will not be divided into lines (chunks). Ignored when
229 * decoding.
230 * @param lineSeparator
231 * Each line of encoded data will end with this sequence of bytes.
232 * @throws IllegalArgumentException
233 * The provided lineSeparator included some Base32 characters. That's not going to work!
234 */
235 public Base32(final int lineLength, final byte[] lineSeparator) {
236 this(lineLength, lineSeparator, false, PAD_DEFAULT);
237 }
238
239 /**
240 * Creates a Base32 / Base32 Hex codec used for decoding and encoding.
241 * <p>
242 * When encoding the line length and line separator are given in the constructor.
243 * </p>
244 * <p>
245 * Line lengths that aren't multiples of 8 will still essentially end up being multiples of 8 in the encoded data.
246 * </p>
247 *
248 * @param lineLength
249 * Each line of encoded data will be at most of the given length (rounded down to nearest multiple of
250 * 8). If lineLength <= 0, then the output will not be divided into lines (chunks). Ignored when
251 * decoding.
252 * @param lineSeparator
253 * Each line of encoded data will end with this sequence of bytes.
254 * @param useHex
255 * if {@code true}, then use Base32 Hex alphabet, otherwise use Base32 alphabet
256 * @throws IllegalArgumentException
257 * The provided lineSeparator included some Base32 characters. That's not going to work! Or the
258 * lineLength > 0 and lineSeparator is null.
259 */
260 public Base32(final int lineLength, final byte[] lineSeparator, final boolean useHex) {
261 this(lineLength, lineSeparator, useHex, PAD_DEFAULT);
262 }
263
264 /**
265 * Creates a Base32 / Base32 Hex codec used for decoding and encoding.
266 * <p>
267 * When encoding the line length and line separator are given in the constructor.
268 * </p>
269 * <p>
270 * Line lengths that aren't multiples of 8 will still essentially end up being multiples of 8 in the encoded data.
271 * </p>
272 *
273 * @param lineLength
274 * Each line of encoded data will be at most of the given length (rounded down to nearest multiple of
275 * 8). If lineLength <= 0, then the output will not be divided into lines (chunks). Ignored when
276 * decoding.
277 * @param lineSeparator
278 * Each line of encoded data will end with this sequence of bytes.
279 * @param useHex
280 * if {@code true}, then use Base32 Hex alphabet, otherwise use Base32 alphabet
281 * @param pad byte used as padding byte.
282 * @throws IllegalArgumentException
283 * The provided lineSeparator included some Base32 characters. That's not going to work! Or the
284 * lineLength > 0 and lineSeparator is null.
285 */
286 public Base32(final int lineLength, final byte[] lineSeparator, final boolean useHex, final byte pad) {
287 super(BYTES_PER_UNENCODED_BLOCK, BYTES_PER_ENCODED_BLOCK, lineLength,
288 lineSeparator == null ? 0 : lineSeparator.length, pad);
289 if (useHex) {
290 this.encodeTable = HEX_ENCODE_TABLE;
291 this.decodeTable = HEX_DECODE_TABLE;
292 } else {
293 this.encodeTable = ENCODE_TABLE;
294 this.decodeTable = DECODE_TABLE;
295 }
296 if (lineLength > 0) {
297 if (lineSeparator == null) {
298 throw new IllegalArgumentException("lineLength " + lineLength + " > 0, but lineSeparator is null");
299 }
300 // Must be done after initializing the tables
301 if (containsAlphabetOrPad(lineSeparator)) {
302 final String sep = StringUtils.newStringUtf8(lineSeparator);
303 throw new IllegalArgumentException("lineSeparator must not contain Base32 characters: [" + sep + "]");
304 }
305 this.encodeSize = BYTES_PER_ENCODED_BLOCK + lineSeparator.length;
306 this.lineSeparator = new byte[lineSeparator.length];
307 System.arraycopy(lineSeparator, 0, this.lineSeparator, 0, lineSeparator.length);
308 } else {
309 this.encodeSize = BYTES_PER_ENCODED_BLOCK;
310 this.lineSeparator = null;
311 }
312 this.decodeSize = this.encodeSize - 1;
313
314 if (isInAlphabet(pad) || isWhiteSpace(pad)) {
315 throw new IllegalArgumentException("pad must not be in alphabet or whitespace");
316 }
317 }
318
319 /**
320 * <p>
321 * Decodes all of the provided data, starting at inPos, for inAvail bytes. Should be called at least twice: once
322 * with the data to decode, and once with inAvail set to "-1" to alert decoder that EOF has been reached. The "-1"
323 * call is not necessary when decoding, but it doesn't hurt, either.
324 * </p>
325 * <p>
326 * Ignores all non-Base32 characters. This is how chunked (e.g. 76 character) data is handled, since CR and LF are
327 * silently ignored, but has implications for other bytes, too. This method subscribes to the garbage-in,
328 * garbage-out philosophy: it will not check the provided data for validity.
329 * </p>
330 *
331 * @param in
332 * byte[] array of ascii data to Base32 decode.
333 * @param inPos
334 * Position to start reading data from.
335 * @param inAvail
336 * Amount of bytes available from input for encoding.
337 * @param context the context to be used
338 *
339 * Output is written to {@link Context#buffer} as 8-bit octets, using {@link Context#pos} as the buffer position
340 */
341 @Override
342 void decode(final byte[] in, int inPos, final int inAvail, final Context context) {
343 // package protected for access from I/O streams
344
345 if (context.eof) {
346 return;
347 }
348 if (inAvail < 0) {
349 context.eof = true;
350 }
351 for (int i = 0; i < inAvail; i++) {
352 final byte b = in[inPos++];
353 if (b == pad) {
354 // We're done.
355 context.eof = true;
356 break;
357 }
358 final byte[] buffer = ensureBufferSize(decodeSize, context);
359 if (b >= 0 && b < this.decodeTable.length) {
360 final int result = this.decodeTable[b];
361 if (result >= 0) {
362 context.modulus = (context.modulus+1) % BYTES_PER_ENCODED_BLOCK;
363 // collect decoded bytes
364 context.lbitWorkArea = (context.lbitWorkArea << BITS_PER_ENCODED_BYTE) + result;
365 if (context.modulus == 0) { // we can output the 5 bytes
366 buffer[context.pos++] = (byte) ((context.lbitWorkArea >> 32) & MASK_8BITS);
367 buffer[context.pos++] = (byte) ((context.lbitWorkArea >> 24) & MASK_8BITS);
368 buffer[context.pos++] = (byte) ((context.lbitWorkArea >> 16) & MASK_8BITS);
369 buffer[context.pos++] = (byte) ((context.lbitWorkArea >> 8) & MASK_8BITS);
370 buffer[context.pos++] = (byte) (context.lbitWorkArea & MASK_8BITS);
371 }
372 }
373 }
374 }
375
376 // Two forms of EOF as far as Base32 decoder is concerned: actual
377 // EOF (-1) and first time '=' character is encountered in stream.
378 // This approach makes the '=' padding characters completely optional.
379 if (context.eof && context.modulus >= 2) { // if modulus < 2, nothing to do
380 final byte[] buffer = ensureBufferSize(decodeSize, context);
381
382 // we ignore partial bytes, i.e. only multiples of 8 count
383 switch (context.modulus) {
384 case 2 : // 10 bits, drop 2 and output one byte
385 buffer[context.pos++] = (byte) ((context.lbitWorkArea >> 2) & MASK_8BITS);
386 break;
387 case 3 : // 15 bits, drop 7 and output 1 byte
388 buffer[context.pos++] = (byte) ((context.lbitWorkArea >> 7) & MASK_8BITS);
389 break;
390 case 4 : // 20 bits = 2*8 + 4
391 context.lbitWorkArea = context.lbitWorkArea >> 4; // drop 4 bits
392 buffer[context.pos++] = (byte) ((context.lbitWorkArea >> 8) & MASK_8BITS);
393 buffer[context.pos++] = (byte) ((context.lbitWorkArea) & MASK_8BITS);
394 break;
395 case 5 : // 25bits = 3*8 + 1
396 context.lbitWorkArea = context.lbitWorkArea >> 1;
397 buffer[context.pos++] = (byte) ((context.lbitWorkArea >> 16) & MASK_8BITS);
398 buffer[context.pos++] = (byte) ((context.lbitWorkArea >> 8) & MASK_8BITS);
399 buffer[context.pos++] = (byte) ((context.lbitWorkArea) & MASK_8BITS);
400 break;
401 case 6 : // 30bits = 3*8 + 6
402 context.lbitWorkArea = context.lbitWorkArea >> 6;
403 buffer[context.pos++] = (byte) ((context.lbitWorkArea >> 16) & MASK_8BITS);
404 buffer[context.pos++] = (byte) ((context.lbitWorkArea >> 8) & MASK_8BITS);
405 buffer[context.pos++] = (byte) ((context.lbitWorkArea) & MASK_8BITS);
406 break;
407 case 7 : // 35 = 4*8 +3
408 context.lbitWorkArea = context.lbitWorkArea >> 3;
409 buffer[context.pos++] = (byte) ((context.lbitWorkArea >> 24) & MASK_8BITS);
410 buffer[context.pos++] = (byte) ((context.lbitWorkArea >> 16) & MASK_8BITS);
411 buffer[context.pos++] = (byte) ((context.lbitWorkArea >> 8) & MASK_8BITS);
412 buffer[context.pos++] = (byte) ((context.lbitWorkArea) & MASK_8BITS);
413 break;
414 default:
415 // modulus can be 0-7, and we excluded 0,1 already
416 throw new IllegalStateException("Impossible modulus "+context.modulus);
417 }
418 }
419 }
420
421 /**
422 * <p>
423 * Encodes all of the provided data, starting at inPos, for inAvail bytes. Must be called at least twice: once with
424 * the data to encode, and once with inAvail set to "-1" to alert encoder that EOF has been reached, so flush last
425 * remaining bytes (if not multiple of 5).
426 * </p>
427 *
428 * @param in
429 * byte[] array of binary data to Base32 encode.
430 * @param inPos
431 * Position to start reading data from.
432 * @param inAvail
433 * Amount of bytes available from input for encoding.
434 * @param context the context to be used
435 */
436 @Override
437 void encode(final byte[] in, int inPos, final int inAvail, final Context context) {
438 // package protected for access from I/O streams
439
440 if (context.eof) {
441 return;
442 }
443 // inAvail < 0 is how we're informed of EOF in the underlying data we're
444 // encoding.
445 if (inAvail < 0) {
446 context.eof = true;
447 if (0 == context.modulus && lineLength == 0) {
448 return; // no leftovers to process and not using chunking
449 }
450 final byte[] buffer = ensureBufferSize(encodeSize, context);
451 final int savedPos = context.pos;
452 switch (context.modulus) { // % 5
453 case 0 :
454 break;
455 case 1 : // Only 1 octet; take top 5 bits then remainder
456 buffer[context.pos++] = encodeTable[(int)(context.lbitWorkArea >> 3) & MASK_5BITS]; // 8-1*5 = 3
457 buffer[context.pos++] = encodeTable[(int)(context.lbitWorkArea << 2) & MASK_5BITS]; // 5-3=2
458 buffer[context.pos++] = pad;
459 buffer[context.pos++] = pad;
460 buffer[context.pos++] = pad;
461 buffer[context.pos++] = pad;
462 buffer[context.pos++] = pad;
463 buffer[context.pos++] = pad;
464 break;
465 case 2 : // 2 octets = 16 bits to use
466 buffer[context.pos++] = encodeTable[(int)(context.lbitWorkArea >> 11) & MASK_5BITS]; // 16-1*5 = 11
467 buffer[context.pos++] = encodeTable[(int)(context.lbitWorkArea >> 6) & MASK_5BITS]; // 16-2*5 = 6
468 buffer[context.pos++] = encodeTable[(int)(context.lbitWorkArea >> 1) & MASK_5BITS]; // 16-3*5 = 1
469 buffer[context.pos++] = encodeTable[(int)(context.lbitWorkArea << 4) & MASK_5BITS]; // 5-1 = 4
470 buffer[context.pos++] = pad;
471 buffer[context.pos++] = pad;
472 buffer[context.pos++] = pad;
473 buffer[context.pos++] = pad;
474 break;
475 case 3 : // 3 octets = 24 bits to use
476 buffer[context.pos++] = encodeTable[(int)(context.lbitWorkArea >> 19) & MASK_5BITS]; // 24-1*5 = 19
477 buffer[context.pos++] = encodeTable[(int)(context.lbitWorkArea >> 14) & MASK_5BITS]; // 24-2*5 = 14
478 buffer[context.pos++] = encodeTable[(int)(context.lbitWorkArea >> 9) & MASK_5BITS]; // 24-3*5 = 9
479 buffer[context.pos++] = encodeTable[(int)(context.lbitWorkArea >> 4) & MASK_5BITS]; // 24-4*5 = 4
480 buffer[context.pos++] = encodeTable[(int)(context.lbitWorkArea << 1) & MASK_5BITS]; // 5-4 = 1
481 buffer[context.pos++] = pad;
482 buffer[context.pos++] = pad;
483 buffer[context.pos++] = pad;
484 break;
485 case 4 : // 4 octets = 32 bits to use
486 buffer[context.pos++] = encodeTable[(int)(context.lbitWorkArea >> 27) & MASK_5BITS]; // 32-1*5 = 27
487 buffer[context.pos++] = encodeTable[(int)(context.lbitWorkArea >> 22) & MASK_5BITS]; // 32-2*5 = 22
488 buffer[context.pos++] = encodeTable[(int)(context.lbitWorkArea >> 17) & MASK_5BITS]; // 32-3*5 = 17
489 buffer[context.pos++] = encodeTable[(int)(context.lbitWorkArea >> 12) & MASK_5BITS]; // 32-4*5 = 12
490 buffer[context.pos++] = encodeTable[(int)(context.lbitWorkArea >> 7) & MASK_5BITS]; // 32-5*5 = 7
491 buffer[context.pos++] = encodeTable[(int)(context.lbitWorkArea >> 2) & MASK_5BITS]; // 32-6*5 = 2
492 buffer[context.pos++] = encodeTable[(int)(context.lbitWorkArea << 3) & MASK_5BITS]; // 5-2 = 3
493 buffer[context.pos++] = pad;
494 break;
495 default:
496 throw new IllegalStateException("Impossible modulus "+context.modulus);
497 }
498 context.currentLinePos += context.pos - savedPos; // keep track of current line position
499 // if currentPos == 0 we are at the start of a line, so don't add CRLF
500 if (lineLength > 0 && context.currentLinePos > 0){ // add chunk separator if required
501 System.arraycopy(lineSeparator, 0, buffer, context.pos, lineSeparator.length);
502 context.pos += lineSeparator.length;
503 }
504 } else {
505 for (int i = 0; i < inAvail; i++) {
506 final byte[] buffer = ensureBufferSize(encodeSize, context);
507 context.modulus = (context.modulus+1) % BYTES_PER_UNENCODED_BLOCK;
508 int b = in[inPos++];
509 if (b < 0) {
510 b += 256;
511 }
512 context.lbitWorkArea = (context.lbitWorkArea << 8) + b; // BITS_PER_BYTE
513 if (0 == context.modulus) { // we have enough bytes to create our output
514 buffer[context.pos++] = encodeTable[(int)(context.lbitWorkArea >> 35) & MASK_5BITS];
515 buffer[context.pos++] = encodeTable[(int)(context.lbitWorkArea >> 30) & MASK_5BITS];
516 buffer[context.pos++] = encodeTable[(int)(context.lbitWorkArea >> 25) & MASK_5BITS];
517 buffer[context.pos++] = encodeTable[(int)(context.lbitWorkArea >> 20) & MASK_5BITS];
518 buffer[context.pos++] = encodeTable[(int)(context.lbitWorkArea >> 15) & MASK_5BITS];
519 buffer[context.pos++] = encodeTable[(int)(context.lbitWorkArea >> 10) & MASK_5BITS];
520 buffer[context.pos++] = encodeTable[(int)(context.lbitWorkArea >> 5) & MASK_5BITS];
521 buffer[context.pos++] = encodeTable[(int)context.lbitWorkArea & MASK_5BITS];
522 context.currentLinePos += BYTES_PER_ENCODED_BLOCK;
523 if (lineLength > 0 && lineLength <= context.currentLinePos) {
524 System.arraycopy(lineSeparator, 0, buffer, context.pos, lineSeparator.length);
525 context.pos += lineSeparator.length;
526 context.currentLinePos = 0;
527 }
528 }
529 }
530 }
531 }
532
533 /**
534 * Returns whether or not the {@code octet} is in the Base32 alphabet.
535 *
536 * @param octet
537 * The value to test
538 * @return {@code true} if the value is defined in the the Base32 alphabet {@code false} otherwise.
539 */
540 @Override
541 public boolean isInAlphabet(final byte octet) {
542 return octet >= 0 && octet < decodeTable.length && decodeTable[octet] != -1;
543 }
544 }