001/* 002 * Licensed to the Apache Software Foundation (ASF) under one or more 003 * contributor license agreements. See the NOTICE file distributed with 004 * this work for additional information regarding copyright ownership. 005 * The ASF licenses this file to You under the Apache License, Version 2.0 006 * (the "License"); you may not use this file except in compliance with 007 * the License. You may obtain a copy of the License at 008 * 009 * http://www.apache.org/licenses/LICENSE-2.0 010 * 011 * Unless required by applicable law or agreed to in writing, software 012 * distributed under the License is distributed on an "AS IS" BASIS, 013 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 014 * See the License for the specific language governing permissions and 015 * limitations under the License. 016 */ 017 018package org.apache.commons.codec.binary; 019 020/** 021 * Provides Base32 encoding and decoding as defined by <a href="http://www.ietf.org/rfc/rfc4648.txt">RFC 4648</a>. 022 * 023 * <p> 024 * The class can be parameterized in the following manner with various constructors: 025 * </p> 026 * <ul> 027 * <li>Whether to use the "base32hex" variant instead of the default "base32"</li> 028 * <li>Line length: Default 76. Line length that aren't multiples of 8 will still essentially end up being multiples of 029 * 8 in the encoded data. 030 * <li>Line separator: Default is CRLF ("\r\n")</li> 031 * </ul> 032 * <p> 033 * This class operates directly on byte streams, and not character streams. 034 * </p> 035 * <p> 036 * This class is thread-safe. 037 * </p> 038 * 039 * @see <a href="http://www.ietf.org/rfc/rfc4648.txt">RFC 4648</a> 040 * 041 * @since 1.5 042 * @version $Id: Base32.html 928559 2014-11-10 02:53:54Z ggregory $ 043 */ 044public class Base32 extends BaseNCodec { 045 046 /** 047 * BASE32 characters are 5 bits in length. 048 * They are formed by taking a block of five octets to form a 40-bit string, 049 * which is converted into eight BASE32 characters. 050 */ 051 private static final int BITS_PER_ENCODED_BYTE = 5; 052 private static final int BYTES_PER_ENCODED_BLOCK = 8; 053 private static final int BYTES_PER_UNENCODED_BLOCK = 5; 054 055 /** 056 * Chunk separator per RFC 2045 section 2.1. 057 * 058 * @see <a href="http://www.ietf.org/rfc/rfc2045.txt">RFC 2045 section 2.1</a> 059 */ 060 private static final byte[] CHUNK_SEPARATOR = {'\r', '\n'}; 061 062 /** 063 * This array is a lookup table that translates Unicode characters drawn from the "Base32 Alphabet" (as specified 064 * in Table 3 of RFC 4648) into their 5-bit positive integer equivalents. Characters that are not in the Base32 065 * alphabet but fall within the bounds of the array are translated to -1. 066 */ 067 private static final byte[] DECODE_TABLE = { 068 // 0 1 2 3 4 5 6 7 8 9 A B C D E F 069 -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, // 00-0f 070 -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, // 10-1f 071 -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, // 20-2f 072 -1, -1, 26, 27, 28, 29, 30, 31, -1, -1, -1, -1, -1, -1, -1, -1, // 30-3f 2-7 073 -1, 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, // 40-4f A-N 074 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, // 50-5a O-Z 075 }; 076 077 /** 078 * This array is a lookup table that translates 5-bit positive integer index values into their "Base32 Alphabet" 079 * equivalents as specified in Table 3 of RFC 4648. 080 */ 081 private static final byte[] ENCODE_TABLE = { 082 'A', 'B', 'C', 'D', 'E', 'F', 'G', 'H', 'I', 'J', 'K', 'L', 'M', 083 'N', 'O', 'P', 'Q', 'R', 'S', 'T', 'U', 'V', 'W', 'X', 'Y', 'Z', 084 '2', '3', '4', '5', '6', '7', 085 }; 086 087 /** 088 * This array is a lookup table that translates Unicode characters drawn from the "Base32 |Hex Alphabet" (as 089 * specified in Table 3 of RFC 4648) into their 5-bit positive integer equivalents. Characters that are not in the 090 * Base32 Hex alphabet but fall within the bounds of the array are translated to -1. 091 */ 092 private static final byte[] HEX_DECODE_TABLE = { 093 // 0 1 2 3 4 5 6 7 8 9 A B C D E F 094 -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, // 00-0f 095 -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, // 10-1f 096 -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, // 20-2f 097 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, -1, -1, -1, -1, -1, -1, // 30-3f 2-7 098 -1, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, // 40-4f A-N 099 25, 26, 27, 28, 29, 30, 31, 32, // 50-57 O-V 100 }; 101 102 /** 103 * This array is a lookup table that translates 5-bit positive integer index values into their 104 * "Base32 Hex Alphabet" equivalents as specified in Table 3 of RFC 4648. 105 */ 106 private static final byte[] HEX_ENCODE_TABLE = { 107 '0', '1', '2', '3', '4', '5', '6', '7', '8', '9', 108 'A', 'B', 'C', 'D', 'E', 'F', 'G', 'H', 'I', 'J', 'K', 'L', 'M', 109 'N', 'O', 'P', 'Q', 'R', 'S', 'T', 'U', 'V', 110 }; 111 112 /** Mask used to extract 5 bits, used when encoding Base32 bytes */ 113 private static final int MASK_5BITS = 0x1f; 114 115 // The static final fields above are used for the original static byte[] methods on Base32. 116 // The private member fields below are used with the new streaming approach, which requires 117 // some state be preserved between calls of encode() and decode(). 118 119 /** 120 * Place holder for the bytes we're dealing with for our based logic. 121 * Bitwise operations store and extract the encoding or decoding from this variable. 122 */ 123 124 /** 125 * Convenience variable to help us determine when our buffer is going to run out of room and needs resizing. 126 * <code>decodeSize = {@link #BYTES_PER_ENCODED_BLOCK} - 1 + lineSeparator.length;</code> 127 */ 128 private final int decodeSize; 129 130 /** 131 * Decode table to use. 132 */ 133 private final byte[] decodeTable; 134 135 /** 136 * Convenience variable to help us determine when our buffer is going to run out of room and needs resizing. 137 * <code>encodeSize = {@link #BYTES_PER_ENCODED_BLOCK} + lineSeparator.length;</code> 138 */ 139 private final int encodeSize; 140 141 /** 142 * Encode table to use. 143 */ 144 private final byte[] encodeTable; 145 146 /** 147 * Line separator for encoding. Not used when decoding. Only used if lineLength > 0. 148 */ 149 private final byte[] lineSeparator; 150 151 /** 152 * Creates a Base32 codec used for decoding and encoding. 153 * <p> 154 * When encoding the line length is 0 (no chunking). 155 * </p> 156 * 157 */ 158 public Base32() { 159 this(false); 160 } 161 162 /** 163 * Creates a Base32 codec used for decoding and encoding. 164 * <p> 165 * When encoding the line length is 0 (no chunking). 166 * </p> 167 * @param pad byte used as padding byte. 168 */ 169 public Base32(final byte pad) { 170 this(false, pad); 171 } 172 173 /** 174 * Creates a Base32 codec used for decoding and encoding. 175 * <p> 176 * When encoding the line length is 0 (no chunking). 177 * </p> 178 * @param useHex if {@code true} then use Base32 Hex alphabet 179 */ 180 public Base32(final boolean useHex) { 181 this(0, null, useHex, PAD_DEFAULT); 182 } 183 184 /** 185 * Creates a Base32 codec used for decoding and encoding. 186 * <p> 187 * When encoding the line length is 0 (no chunking). 188 * </p> 189 * @param useHex if {@code true} then use Base32 Hex alphabet 190 * @param pad byte used as padding byte. 191 */ 192 public Base32(final boolean useHex, final byte pad) { 193 this(0, null, useHex, pad); 194 } 195 196 /** 197 * Creates a Base32 codec used for decoding and encoding. 198 * <p> 199 * When encoding the line length is given in the constructor, the line separator is CRLF. 200 * </p> 201 * 202 * @param lineLength 203 * Each line of encoded data will be at most of the given length (rounded down to nearest multiple of 204 * 8). If lineLength <= 0, then the output will not be divided into lines (chunks). Ignored when 205 * decoding. 206 */ 207 public Base32(final int lineLength) { 208 this(lineLength, CHUNK_SEPARATOR); 209 } 210 211 /** 212 * Creates a Base32 codec used for decoding and encoding. 213 * <p> 214 * When encoding the line length and line separator are given in the constructor. 215 * </p> 216 * <p> 217 * Line lengths that aren't multiples of 8 will still essentially end up being multiples of 8 in the encoded data. 218 * </p> 219 * 220 * @param lineLength 221 * Each line of encoded data will be at most of the given length (rounded down to nearest multiple of 222 * 8). If lineLength <= 0, then the output will not be divided into lines (chunks). Ignored when 223 * decoding. 224 * @param lineSeparator 225 * Each line of encoded data will end with this sequence of bytes. 226 * @throws IllegalArgumentException 227 * The provided lineSeparator included some Base32 characters. That's not going to work! 228 */ 229 public Base32(final int lineLength, final byte[] lineSeparator) { 230 this(lineLength, lineSeparator, false, PAD_DEFAULT); 231 } 232 233 /** 234 * Creates a Base32 / Base32 Hex codec used for decoding and encoding. 235 * <p> 236 * When encoding the line length and line separator are given in the constructor. 237 * </p> 238 * <p> 239 * Line lengths that aren't multiples of 8 will still essentially end up being multiples of 8 in the encoded data. 240 * </p> 241 * 242 * @param lineLength 243 * Each line of encoded data will be at most of the given length (rounded down to nearest multiple of 244 * 8). If lineLength <= 0, then the output will not be divided into lines (chunks). Ignored when 245 * decoding. 246 * @param lineSeparator 247 * Each line of encoded data will end with this sequence of bytes. 248 * @param useHex 249 * if {@code true}, then use Base32 Hex alphabet, otherwise use Base32 alphabet 250 * @throws IllegalArgumentException 251 * The provided lineSeparator included some Base32 characters. That's not going to work! Or the 252 * lineLength > 0 and lineSeparator is null. 253 */ 254 public Base32(final int lineLength, final byte[] lineSeparator, final boolean useHex) { 255 this(lineLength, lineSeparator, useHex, PAD_DEFAULT); 256 } 257 258 /** 259 * Creates a Base32 / Base32 Hex codec used for decoding and encoding. 260 * <p> 261 * When encoding the line length and line separator are given in the constructor. 262 * </p> 263 * <p> 264 * Line lengths that aren't multiples of 8 will still essentially end up being multiples of 8 in the encoded data. 265 * </p> 266 * 267 * @param lineLength 268 * Each line of encoded data will be at most of the given length (rounded down to nearest multiple of 269 * 8). If lineLength <= 0, then the output will not be divided into lines (chunks). Ignored when 270 * decoding. 271 * @param lineSeparator 272 * Each line of encoded data will end with this sequence of bytes. 273 * @param useHex 274 * if {@code true}, then use Base32 Hex alphabet, otherwise use Base32 alphabet 275 * @param pad byte used as padding byte. 276 * @throws IllegalArgumentException 277 * The provided lineSeparator included some Base32 characters. That's not going to work! Or the 278 * lineLength > 0 and lineSeparator is null. 279 */ 280 public Base32(final int lineLength, final byte[] lineSeparator, final boolean useHex, final byte pad) { 281 super(BYTES_PER_UNENCODED_BLOCK, BYTES_PER_ENCODED_BLOCK, lineLength, 282 lineSeparator == null ? 0 : lineSeparator.length, pad); 283 if (useHex) { 284 this.encodeTable = HEX_ENCODE_TABLE; 285 this.decodeTable = HEX_DECODE_TABLE; 286 } else { 287 this.encodeTable = ENCODE_TABLE; 288 this.decodeTable = DECODE_TABLE; 289 } 290 if (lineLength > 0) { 291 if (lineSeparator == null) { 292 throw new IllegalArgumentException("lineLength " + lineLength + " > 0, but lineSeparator is null"); 293 } 294 // Must be done after initializing the tables 295 if (containsAlphabetOrPad(lineSeparator)) { 296 final String sep = StringUtils.newStringUtf8(lineSeparator); 297 throw new IllegalArgumentException("lineSeparator must not contain Base32 characters: [" + sep + "]"); 298 } 299 this.encodeSize = BYTES_PER_ENCODED_BLOCK + lineSeparator.length; 300 this.lineSeparator = new byte[lineSeparator.length]; 301 System.arraycopy(lineSeparator, 0, this.lineSeparator, 0, lineSeparator.length); 302 } else { 303 this.encodeSize = BYTES_PER_ENCODED_BLOCK; 304 this.lineSeparator = null; 305 } 306 this.decodeSize = this.encodeSize - 1; 307 308 if (isInAlphabet(pad) || isWhiteSpace(pad)) { 309 throw new IllegalArgumentException("pad must not be in alphabet or whitespace"); 310 } 311 } 312 313 /** 314 * <p> 315 * Decodes all of the provided data, starting at inPos, for inAvail bytes. Should be called at least twice: once 316 * with the data to decode, and once with inAvail set to "-1" to alert decoder that EOF has been reached. The "-1" 317 * call is not necessary when decoding, but it doesn't hurt, either. 318 * </p> 319 * <p> 320 * Ignores all non-Base32 characters. This is how chunked (e.g. 76 character) data is handled, since CR and LF are 321 * silently ignored, but has implications for other bytes, too. This method subscribes to the garbage-in, 322 * garbage-out philosophy: it will not check the provided data for validity. 323 * </p> 324 * 325 * @param in 326 * byte[] array of ascii data to Base32 decode. 327 * @param inPos 328 * Position to start reading data from. 329 * @param inAvail 330 * Amount of bytes available from input for encoding. 331 * @param context the context to be used 332 * 333 * Output is written to {@link Context#buffer} as 8-bit octets, using {@link Context#pos} as the buffer position 334 */ 335 @Override 336 void decode(final byte[] in, int inPos, final int inAvail, final Context context) { 337 // package protected for access from I/O streams 338 339 if (context.eof) { 340 return; 341 } 342 if (inAvail < 0) { 343 context.eof = true; 344 } 345 for (int i = 0; i < inAvail; i++) { 346 final byte b = in[inPos++]; 347 if (b == pad) { 348 // We're done. 349 context.eof = true; 350 break; 351 } else { 352 final byte[] buffer = ensureBufferSize(decodeSize, context); 353 if (b >= 0 && b < this.decodeTable.length) { 354 final int result = this.decodeTable[b]; 355 if (result >= 0) { 356 context.modulus = (context.modulus+1) % BYTES_PER_ENCODED_BLOCK; 357 // collect decoded bytes 358 context.lbitWorkArea = (context.lbitWorkArea << BITS_PER_ENCODED_BYTE) + result; 359 if (context.modulus == 0) { // we can output the 5 bytes 360 buffer[context.pos++] = (byte) ((context.lbitWorkArea >> 32) & MASK_8BITS); 361 buffer[context.pos++] = (byte) ((context.lbitWorkArea >> 24) & MASK_8BITS); 362 buffer[context.pos++] = (byte) ((context.lbitWorkArea >> 16) & MASK_8BITS); 363 buffer[context.pos++] = (byte) ((context.lbitWorkArea >> 8) & MASK_8BITS); 364 buffer[context.pos++] = (byte) (context.lbitWorkArea & MASK_8BITS); 365 } 366 } 367 } 368 } 369 } 370 371 // Two forms of EOF as far as Base32 decoder is concerned: actual 372 // EOF (-1) and first time '=' character is encountered in stream. 373 // This approach makes the '=' padding characters completely optional. 374 if (context.eof && context.modulus >= 2) { // if modulus < 2, nothing to do 375 final byte[] buffer = ensureBufferSize(decodeSize, context); 376 377 // we ignore partial bytes, i.e. only multiples of 8 count 378 switch (context.modulus) { 379 case 2 : // 10 bits, drop 2 and output one byte 380 buffer[context.pos++] = (byte) ((context.lbitWorkArea >> 2) & MASK_8BITS); 381 break; 382 case 3 : // 15 bits, drop 7 and output 1 byte 383 buffer[context.pos++] = (byte) ((context.lbitWorkArea >> 7) & MASK_8BITS); 384 break; 385 case 4 : // 20 bits = 2*8 + 4 386 context.lbitWorkArea = context.lbitWorkArea >> 4; // drop 4 bits 387 buffer[context.pos++] = (byte) ((context.lbitWorkArea >> 8) & MASK_8BITS); 388 buffer[context.pos++] = (byte) ((context.lbitWorkArea) & MASK_8BITS); 389 break; 390 case 5 : // 25bits = 3*8 + 1 391 context.lbitWorkArea = context.lbitWorkArea >> 1; 392 buffer[context.pos++] = (byte) ((context.lbitWorkArea >> 16) & MASK_8BITS); 393 buffer[context.pos++] = (byte) ((context.lbitWorkArea >> 8) & MASK_8BITS); 394 buffer[context.pos++] = (byte) ((context.lbitWorkArea) & MASK_8BITS); 395 break; 396 case 6 : // 30bits = 3*8 + 6 397 context.lbitWorkArea = context.lbitWorkArea >> 6; 398 buffer[context.pos++] = (byte) ((context.lbitWorkArea >> 16) & MASK_8BITS); 399 buffer[context.pos++] = (byte) ((context.lbitWorkArea >> 8) & MASK_8BITS); 400 buffer[context.pos++] = (byte) ((context.lbitWorkArea) & MASK_8BITS); 401 break; 402 case 7 : // 35 = 4*8 +3 403 context.lbitWorkArea = context.lbitWorkArea >> 3; 404 buffer[context.pos++] = (byte) ((context.lbitWorkArea >> 24) & MASK_8BITS); 405 buffer[context.pos++] = (byte) ((context.lbitWorkArea >> 16) & MASK_8BITS); 406 buffer[context.pos++] = (byte) ((context.lbitWorkArea >> 8) & MASK_8BITS); 407 buffer[context.pos++] = (byte) ((context.lbitWorkArea) & MASK_8BITS); 408 break; 409 default: 410 // modulus can be 0-7, and we excluded 0,1 already 411 throw new IllegalStateException("Impossible modulus "+context.modulus); 412 } 413 } 414 } 415 416 /** 417 * <p> 418 * Encodes all of the provided data, starting at inPos, for inAvail bytes. Must be called at least twice: once with 419 * the data to encode, and once with inAvail set to "-1" to alert encoder that EOF has been reached, so flush last 420 * remaining bytes (if not multiple of 5). 421 * </p> 422 * 423 * @param in 424 * byte[] array of binary data to Base32 encode. 425 * @param inPos 426 * Position to start reading data from. 427 * @param inAvail 428 * Amount of bytes available from input for encoding. 429 * @param context the context to be used 430 */ 431 @Override 432 void encode(final byte[] in, int inPos, final int inAvail, final Context context) { 433 // package protected for access from I/O streams 434 435 if (context.eof) { 436 return; 437 } 438 // inAvail < 0 is how we're informed of EOF in the underlying data we're 439 // encoding. 440 if (inAvail < 0) { 441 context.eof = true; 442 if (0 == context.modulus && lineLength == 0) { 443 return; // no leftovers to process and not using chunking 444 } 445 final byte[] buffer = ensureBufferSize(encodeSize, context); 446 final int savedPos = context.pos; 447 switch (context.modulus) { // % 5 448 case 0 : 449 break; 450 case 1 : // Only 1 octet; take top 5 bits then remainder 451 buffer[context.pos++] = encodeTable[(int)(context.lbitWorkArea >> 3) & MASK_5BITS]; // 8-1*5 = 3 452 buffer[context.pos++] = encodeTable[(int)(context.lbitWorkArea << 2) & MASK_5BITS]; // 5-3=2 453 buffer[context.pos++] = pad; 454 buffer[context.pos++] = pad; 455 buffer[context.pos++] = pad; 456 buffer[context.pos++] = pad; 457 buffer[context.pos++] = pad; 458 buffer[context.pos++] = pad; 459 break; 460 case 2 : // 2 octets = 16 bits to use 461 buffer[context.pos++] = encodeTable[(int)(context.lbitWorkArea >> 11) & MASK_5BITS]; // 16-1*5 = 11 462 buffer[context.pos++] = encodeTable[(int)(context.lbitWorkArea >> 6) & MASK_5BITS]; // 16-2*5 = 6 463 buffer[context.pos++] = encodeTable[(int)(context.lbitWorkArea >> 1) & MASK_5BITS]; // 16-3*5 = 1 464 buffer[context.pos++] = encodeTable[(int)(context.lbitWorkArea << 4) & MASK_5BITS]; // 5-1 = 4 465 buffer[context.pos++] = pad; 466 buffer[context.pos++] = pad; 467 buffer[context.pos++] = pad; 468 buffer[context.pos++] = pad; 469 break; 470 case 3 : // 3 octets = 24 bits to use 471 buffer[context.pos++] = encodeTable[(int)(context.lbitWorkArea >> 19) & MASK_5BITS]; // 24-1*5 = 19 472 buffer[context.pos++] = encodeTable[(int)(context.lbitWorkArea >> 14) & MASK_5BITS]; // 24-2*5 = 14 473 buffer[context.pos++] = encodeTable[(int)(context.lbitWorkArea >> 9) & MASK_5BITS]; // 24-3*5 = 9 474 buffer[context.pos++] = encodeTable[(int)(context.lbitWorkArea >> 4) & MASK_5BITS]; // 24-4*5 = 4 475 buffer[context.pos++] = encodeTable[(int)(context.lbitWorkArea << 1) & MASK_5BITS]; // 5-4 = 1 476 buffer[context.pos++] = pad; 477 buffer[context.pos++] = pad; 478 buffer[context.pos++] = pad; 479 break; 480 case 4 : // 4 octets = 32 bits to use 481 buffer[context.pos++] = encodeTable[(int)(context.lbitWorkArea >> 27) & MASK_5BITS]; // 32-1*5 = 27 482 buffer[context.pos++] = encodeTable[(int)(context.lbitWorkArea >> 22) & MASK_5BITS]; // 32-2*5 = 22 483 buffer[context.pos++] = encodeTable[(int)(context.lbitWorkArea >> 17) & MASK_5BITS]; // 32-3*5 = 17 484 buffer[context.pos++] = encodeTable[(int)(context.lbitWorkArea >> 12) & MASK_5BITS]; // 32-4*5 = 12 485 buffer[context.pos++] = encodeTable[(int)(context.lbitWorkArea >> 7) & MASK_5BITS]; // 32-5*5 = 7 486 buffer[context.pos++] = encodeTable[(int)(context.lbitWorkArea >> 2) & MASK_5BITS]; // 32-6*5 = 2 487 buffer[context.pos++] = encodeTable[(int)(context.lbitWorkArea << 3) & MASK_5BITS]; // 5-2 = 3 488 buffer[context.pos++] = pad; 489 break; 490 default: 491 throw new IllegalStateException("Impossible modulus "+context.modulus); 492 } 493 context.currentLinePos += context.pos - savedPos; // keep track of current line position 494 // if currentPos == 0 we are at the start of a line, so don't add CRLF 495 if (lineLength > 0 && context.currentLinePos > 0){ // add chunk separator if required 496 System.arraycopy(lineSeparator, 0, buffer, context.pos, lineSeparator.length); 497 context.pos += lineSeparator.length; 498 } 499 } else { 500 for (int i = 0; i < inAvail; i++) { 501 final byte[] buffer = ensureBufferSize(encodeSize, context); 502 context.modulus = (context.modulus+1) % BYTES_PER_UNENCODED_BLOCK; 503 int b = in[inPos++]; 504 if (b < 0) { 505 b += 256; 506 } 507 context.lbitWorkArea = (context.lbitWorkArea << 8) + b; // BITS_PER_BYTE 508 if (0 == context.modulus) { // we have enough bytes to create our output 509 buffer[context.pos++] = encodeTable[(int)(context.lbitWorkArea >> 35) & MASK_5BITS]; 510 buffer[context.pos++] = encodeTable[(int)(context.lbitWorkArea >> 30) & MASK_5BITS]; 511 buffer[context.pos++] = encodeTable[(int)(context.lbitWorkArea >> 25) & MASK_5BITS]; 512 buffer[context.pos++] = encodeTable[(int)(context.lbitWorkArea >> 20) & MASK_5BITS]; 513 buffer[context.pos++] = encodeTable[(int)(context.lbitWorkArea >> 15) & MASK_5BITS]; 514 buffer[context.pos++] = encodeTable[(int)(context.lbitWorkArea >> 10) & MASK_5BITS]; 515 buffer[context.pos++] = encodeTable[(int)(context.lbitWorkArea >> 5) & MASK_5BITS]; 516 buffer[context.pos++] = encodeTable[(int)context.lbitWorkArea & MASK_5BITS]; 517 context.currentLinePos += BYTES_PER_ENCODED_BLOCK; 518 if (lineLength > 0 && lineLength <= context.currentLinePos) { 519 System.arraycopy(lineSeparator, 0, buffer, context.pos, lineSeparator.length); 520 context.pos += lineSeparator.length; 521 context.currentLinePos = 0; 522 } 523 } 524 } 525 } 526 } 527 528 /** 529 * Returns whether or not the {@code octet} is in the Base32 alphabet. 530 * 531 * @param octet 532 * The value to test 533 * @return {@code true} if the value is defined in the the Base32 alphabet {@code false} otherwise. 534 */ 535 @Override 536 public boolean isInAlphabet(final byte octet) { 537 return octet >= 0 && octet < decodeTable.length && decodeTable[octet] != -1; 538 } 539}