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 */ 017 018 package org.apache.commons.net.util; 019 020 import java.io.UnsupportedEncodingException; 021 import java.math.BigInteger; 022 023 024 025 /** 026 * Provides Base64 encoding and decoding as defined by RFC 2045. 027 * 028 * <p> 029 * This class implements section <cite>6.8. Base64 Content-Transfer-Encoding</cite> from RFC 2045 <cite>Multipurpose 030 * Internet Mail Extensions (MIME) Part One: Format of Internet Message Bodies</cite> by Freed and Borenstein. 031 * </p> 032 * <p> 033 * The class can be parameterized in the following manner with various constructors: 034 * <ul> 035 * <li>URL-safe mode: Default off.</li> 036 * <li>Line length: Default 76. Line length that aren't multiples of 4 will still essentially end up being multiples of 037 * 4 in the encoded data. 038 * <li>Line separator: Default is CRLF ("\r\n")</li> 039 * </ul> 040 * </p> 041 * <p> 042 * Since this class operates directly on byte streams, and not character streams, it is hard-coded to only encode/decode 043 * character encodings which are compatible with the lower 127 ASCII chart (ISO-8859-1, Windows-1252, UTF-8, etc). 044 * </p> 045 * 046 * @see <a href="http://www.ietf.org/rfc/rfc2045.txt">RFC 2045</a> 047 * @author Apache Software Foundation 048 * @since 2.2 049 * @version $Id$ 050 */ 051 public class Base64 { 052 private static final int DEFAULT_BUFFER_RESIZE_FACTOR = 2; 053 054 private static final int DEFAULT_BUFFER_SIZE = 8192; 055 056 /** 057 * Chunk size per RFC 2045 section 6.8. 058 * 059 * <p> 060 * The {@value} character limit does not count the trailing CRLF, but counts all other characters, including any 061 * equal signs. 062 * </p> 063 * 064 * @see <a href="http://www.ietf.org/rfc/rfc2045.txt">RFC 2045 section 6.8</a> 065 */ 066 static final int CHUNK_SIZE = 76; 067 068 /** 069 * Chunk separator per RFC 2045 section 2.1. 070 * 071 * <p> 072 * N.B. The next major release may break compatibility and make this field private. 073 * </p> 074 * 075 * @see <a href="http://www.ietf.org/rfc/rfc2045.txt">RFC 2045 section 2.1</a> 076 */ 077 static final byte[] CHUNK_SEPARATOR = {'\r', '\n'}; 078 079 /** 080 * This array is a lookup table that translates 6-bit positive integer index values into their "Base64 Alphabet" 081 * equivalents as specified in Table 1 of RFC 2045. 082 * 083 * Thanks to "commons" project in ws.apache.org for this code. 084 * http://svn.apache.org/repos/asf/webservices/commons/trunk/modules/util/ 085 */ 086 private static final byte[] STANDARD_ENCODE_TABLE = { 087 'A', 'B', 'C', 'D', 'E', 'F', 'G', 'H', 'I', 'J', 'K', 'L', 'M', 088 'N', 'O', 'P', 'Q', 'R', 'S', 'T', 'U', 'V', 'W', 'X', 'Y', 'Z', 089 'a', 'b', 'c', 'd', 'e', 'f', 'g', 'h', 'i', 'j', 'k', 'l', 'm', 090 'n', 'o', 'p', 'q', 'r', 's', 't', 'u', 'v', 'w', 'x', 'y', 'z', 091 '0', '1', '2', '3', '4', '5', '6', '7', '8', '9', '+', '/' 092 }; 093 094 /** 095 * This is a copy of the STANDARD_ENCODE_TABLE above, but with + and / 096 * changed to - and _ to make the encoded Base64 results more URL-SAFE. 097 * This table is only used when the Base64's mode is set to URL-SAFE. 098 */ 099 private static final byte[] URL_SAFE_ENCODE_TABLE = { 100 'A', 'B', 'C', 'D', 'E', 'F', 'G', 'H', 'I', 'J', 'K', 'L', 'M', 101 'N', 'O', 'P', 'Q', 'R', 'S', 'T', 'U', 'V', 'W', 'X', 'Y', 'Z', 102 'a', 'b', 'c', 'd', 'e', 'f', 'g', 'h', 'i', 'j', 'k', 'l', 'm', 103 'n', 'o', 'p', 'q', 'r', 's', 't', 'u', 'v', 'w', 'x', 'y', 'z', 104 '0', '1', '2', '3', '4', '5', '6', '7', '8', '9', '-', '_' 105 }; 106 107 /** 108 * Byte used to pad output. 109 */ 110 private static final byte PAD = '='; 111 112 /** 113 * This array is a lookup table that translates Unicode characters drawn from the "Base64 Alphabet" (as specified in 114 * Table 1 of RFC 2045) into their 6-bit positive integer equivalents. Characters that are not in the Base64 115 * alphabet but fall within the bounds of the array are translated to -1. 116 * 117 * Note: '+' and '-' both decode to 62. '/' and '_' both decode to 63. This means decoder seamlessly handles both 118 * URL_SAFE and STANDARD base64. (The encoder, on the other hand, needs to know ahead of time what to emit). 119 * 120 * Thanks to "commons" project in ws.apache.org for this code. 121 * http://svn.apache.org/repos/asf/webservices/commons/trunk/modules/util/ 122 */ 123 private static final byte[] DECODE_TABLE = { 124 -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, 125 -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, 126 -1, -1, -1, -1, -1, -1, -1, -1, -1, 62, -1, 62, -1, 63, 52, 53, 54, 127 55, 56, 57, 58, 59, 60, 61, -1, -1, -1, -1, -1, -1, -1, 0, 1, 2, 3, 4, 128 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 129 24, 25, -1, -1, -1, -1, 63, -1, 26, 27, 28, 29, 30, 31, 32, 33, 34, 130 35, 36, 37, 38, 39, 40, 41, 42, 43, 44, 45, 46, 47, 48, 49, 50, 51 131 }; 132 133 /** Mask used to extract 6 bits, used when encoding */ 134 private static final int MASK_6BITS = 0x3f; 135 136 /** Mask used to extract 8 bits, used in decoding base64 bytes */ 137 private static final int MASK_8BITS = 0xff; 138 139 // The static final fields above are used for the original static byte[] methods on Base64. 140 // The private member fields below are used with the new streaming approach, which requires 141 // some state be preserved between calls of encode() and decode(). 142 143 /** 144 * Encode table to use: either STANDARD or URL_SAFE. Note: the DECODE_TABLE above remains static because it is able 145 * to decode both STANDARD and URL_SAFE streams, but the encodeTable must be a member variable so we can switch 146 * between the two modes. 147 */ 148 private final byte[] encodeTable; 149 150 /** 151 * Line length for encoding. Not used when decoding. A value of zero or less implies no chunking of the base64 152 * encoded data. 153 */ 154 private final int lineLength; 155 156 /** 157 * Line separator for encoding. Not used when decoding. Only used if lineLength > 0. 158 */ 159 private final byte[] lineSeparator; 160 161 /** 162 * Convenience variable to help us determine when our buffer is going to run out of room and needs resizing. 163 * <code>decodeSize = 3 + lineSeparator.length;</code> 164 */ 165 private final int decodeSize; 166 167 /** 168 * Convenience variable to help us determine when our buffer is going to run out of room and needs resizing. 169 * <code>encodeSize = 4 + lineSeparator.length;</code> 170 */ 171 private final int encodeSize; 172 173 /** 174 * Buffer for streaming. 175 */ 176 private byte[] buffer; 177 178 /** 179 * Position where next character should be written in the buffer. 180 */ 181 private int pos; 182 183 /** 184 * Position where next character should be read from the buffer. 185 */ 186 private int readPos; 187 188 /** 189 * Variable tracks how many characters have been written to the current line. Only used when encoding. We use it to 190 * make sure each encoded line never goes beyond lineLength (if lineLength > 0). 191 */ 192 private int currentLinePos; 193 194 /** 195 * Writes to the buffer only occur after every 3 reads when encoding, an every 4 reads when decoding. This variable 196 * helps track that. 197 */ 198 private int modulus; 199 200 /** 201 * Boolean flag to indicate the EOF has been reached. Once EOF has been reached, this Base64 object becomes useless, 202 * and must be thrown away. 203 */ 204 private boolean eof; 205 206 /** 207 * Place holder for the 3 bytes we're dealing with for our base64 logic. Bitwise operations store and extract the 208 * base64 encoding or decoding from this variable. 209 */ 210 private int x; 211 212 /** 213 * Creates a Base64 codec used for decoding (all modes) and encoding in URL-unsafe mode. 214 * <p> 215 * When encoding the line length is 76, the line separator is CRLF, and the encoding table is STANDARD_ENCODE_TABLE. 216 * </p> 217 * 218 * <p> 219 * When decoding all variants are supported. 220 * </p> 221 */ 222 public Base64() { 223 this(false); 224 } 225 226 /** 227 * Creates a Base64 codec used for decoding (all modes) and encoding in the given URL-safe mode. 228 * <p> 229 * When encoding the line length is 76, the line separator is CRLF, and the encoding table is STANDARD_ENCODE_TABLE. 230 * </p> 231 * 232 * <p> 233 * When decoding all variants are supported. 234 * </p> 235 * 236 * @param urlSafe 237 * if <code>true</code>, URL-safe encoding is used. In most cases this should be set to 238 * <code>false</code>. 239 * @since 1.4 240 */ 241 public Base64(boolean urlSafe) { 242 this(CHUNK_SIZE, CHUNK_SEPARATOR, urlSafe); 243 } 244 245 /** 246 * Creates a Base64 codec used for decoding (all modes) and encoding in URL-unsafe mode. 247 * <p> 248 * When encoding the line length is given in the constructor, the line separator is CRLF, and the encoding table is 249 * STANDARD_ENCODE_TABLE. 250 * </p> 251 * <p> 252 * Line lengths that aren't multiples of 4 will still essentially end up being multiples of 4 in the encoded data. 253 * </p> 254 * <p> 255 * When decoding all variants are supported. 256 * </p> 257 * 258 * @param lineLength 259 * Each line of encoded data will be at most of the given length (rounded down to nearest multiple of 4). 260 * If lineLength <= 0, then the output will not be divided into lines (chunks). Ignored when decoding. 261 * @since 1.4 262 */ 263 public Base64(int lineLength) { 264 this(lineLength, CHUNK_SEPARATOR); 265 } 266 267 /** 268 * Creates a Base64 codec used for decoding (all modes) and encoding in URL-unsafe mode. 269 * <p> 270 * When encoding the line length and line separator are given in the constructor, and the encoding table is 271 * STANDARD_ENCODE_TABLE. 272 * </p> 273 * <p> 274 * Line lengths that aren't multiples of 4 will still essentially end up being multiples of 4 in the encoded data. 275 * </p> 276 * <p> 277 * When decoding all variants are supported. 278 * </p> 279 * 280 * @param lineLength 281 * Each line of encoded data will be at most of the given length (rounded down to nearest multiple of 4). 282 * If lineLength <= 0, then the output will not be divided into lines (chunks). Ignored when decoding. 283 * @param lineSeparator 284 * Each line of encoded data will end with this sequence of bytes. 285 * @throws IllegalArgumentException 286 * Thrown when the provided lineSeparator included some base64 characters. 287 * @since 1.4 288 */ 289 public Base64(int lineLength, byte[] lineSeparator) { 290 this(lineLength, lineSeparator, false); 291 } 292 293 /** 294 * Creates a Base64 codec used for decoding (all modes) and encoding in URL-unsafe mode. 295 * <p> 296 * When encoding the line length and line separator are given in the constructor, and the encoding table is 297 * STANDARD_ENCODE_TABLE. 298 * </p> 299 * <p> 300 * Line lengths that aren't multiples of 4 will still essentially end up being multiples of 4 in the encoded data. 301 * </p> 302 * <p> 303 * When decoding all variants are supported. 304 * </p> 305 * 306 * @param lineLength 307 * Each line of encoded data will be at most of the given length (rounded down to nearest multiple of 4). 308 * If lineLength <= 0, then the output will not be divided into lines (chunks). Ignored when decoding. 309 * @param lineSeparator 310 * Each line of encoded data will end with this sequence of bytes. 311 * @param urlSafe 312 * Instead of emitting '+' and '/' we emit '-' and '_' respectively. urlSafe is only applied to encode 313 * operations. Decoding seamlessly handles both modes. 314 * @throws IllegalArgumentException 315 * The provided lineSeparator included some base64 characters. That's not going to work! 316 * @since 1.4 317 */ 318 public Base64(int lineLength, byte[] lineSeparator, boolean urlSafe) { 319 if (lineSeparator == null) { 320 lineLength = 0; // disable chunk-separating 321 lineSeparator = CHUNK_SEPARATOR; // this just gets ignored 322 } 323 this.lineLength = lineLength > 0 ? (lineLength / 4) * 4 : 0; 324 this.lineSeparator = new byte[lineSeparator.length]; 325 System.arraycopy(lineSeparator, 0, this.lineSeparator, 0, lineSeparator.length); 326 if (lineLength > 0) { 327 this.encodeSize = 4 + lineSeparator.length; 328 } else { 329 this.encodeSize = 4; 330 } 331 this.decodeSize = this.encodeSize - 1; 332 if (containsBase64Byte(lineSeparator)) { 333 String sep = newStringUtf8(lineSeparator); 334 throw new IllegalArgumentException("lineSeperator must not contain base64 characters: [" + sep + "]"); 335 } 336 this.encodeTable = urlSafe ? URL_SAFE_ENCODE_TABLE : STANDARD_ENCODE_TABLE; 337 } 338 339 /** 340 * Returns our current encode mode. True if we're URL-SAFE, false otherwise. 341 * 342 * @return true if we're in URL-SAFE mode, false otherwise. 343 * @since 1.4 344 */ 345 public boolean isUrlSafe() { 346 return this.encodeTable == URL_SAFE_ENCODE_TABLE; 347 } 348 349 /** 350 * Returns true if this Base64 object has buffered data for reading. 351 * 352 * @return true if there is Base64 object still available for reading. 353 */ 354 boolean hasData() { 355 return this.buffer != null; 356 } 357 358 /** 359 * Returns the amount of buffered data available for reading. 360 * 361 * @return The amount of buffered data available for reading. 362 */ 363 int avail() { 364 return buffer != null ? pos - readPos : 0; 365 } 366 367 /** Doubles our buffer. */ 368 private void resizeBuffer() { 369 if (buffer == null) { 370 buffer = new byte[DEFAULT_BUFFER_SIZE]; 371 pos = 0; 372 readPos = 0; 373 } else { 374 byte[] b = new byte[buffer.length * DEFAULT_BUFFER_RESIZE_FACTOR]; 375 System.arraycopy(buffer, 0, b, 0, buffer.length); 376 buffer = b; 377 } 378 } 379 380 /** 381 * Extracts buffered data into the provided byte[] array, starting at position bPos, up to a maximum of bAvail 382 * bytes. Returns how many bytes were actually extracted. 383 * 384 * @param b 385 * byte[] array to extract the buffered data into. 386 * @param bPos 387 * position in byte[] array to start extraction at. 388 * @param bAvail 389 * amount of bytes we're allowed to extract. We may extract fewer (if fewer are available). 390 * @return The number of bytes successfully extracted into the provided byte[] array. 391 */ 392 int readResults(byte[] b, int bPos, int bAvail) { 393 if (buffer != null) { 394 int len = Math.min(avail(), bAvail); 395 if (buffer != b) { 396 System.arraycopy(buffer, readPos, b, bPos, len); 397 readPos += len; 398 if (readPos >= pos) { 399 buffer = null; 400 } 401 } else { 402 // Re-using the original consumer's output array is only 403 // allowed for one round. 404 buffer = null; 405 } 406 return len; 407 } 408 return eof ? -1 : 0; 409 } 410 411 /** 412 * Sets the streaming buffer. This is a small optimization where we try to buffer directly to the consumer's output 413 * array for one round (if the consumer calls this method first) instead of starting our own buffer. 414 * 415 * @param out 416 * byte[] array to buffer directly to. 417 * @param outPos 418 * Position to start buffering into. 419 * @param outAvail 420 * Amount of bytes available for direct buffering. 421 */ 422 void setInitialBuffer(byte[] out, int outPos, int outAvail) { 423 // We can re-use consumer's original output array under 424 // special circumstances, saving on some System.arraycopy(). 425 if (out != null && out.length == outAvail) { 426 buffer = out; 427 pos = outPos; 428 readPos = outPos; 429 } 430 } 431 432 /** 433 * <p> 434 * Encodes all of the provided data, starting at inPos, for inAvail bytes. Must be called at least twice: once with 435 * the data to encode, and once with inAvail set to "-1" to alert encoder that EOF has been reached, so flush last 436 * remaining bytes (if not multiple of 3). 437 * </p> 438 * <p> 439 * Thanks to "commons" project in ws.apache.org for the bitwise operations, and general approach. 440 * http://svn.apache.org/repos/asf/webservices/commons/trunk/modules/util/ 441 * </p> 442 * 443 * @param in 444 * byte[] array of binary data to base64 encode. 445 * @param inPos 446 * Position to start reading data from. 447 * @param inAvail 448 * Amount of bytes available from input for encoding. 449 */ 450 void encode(byte[] in, int inPos, int inAvail) { 451 if (eof) { 452 return; 453 } 454 // inAvail < 0 is how we're informed of EOF in the underlying data we're 455 // encoding. 456 if (inAvail < 0) { 457 eof = true; 458 if (buffer == null || buffer.length - pos < encodeSize) { 459 resizeBuffer(); 460 } 461 switch (modulus) { 462 case 1 : 463 buffer[pos++] = encodeTable[(x >> 2) & MASK_6BITS]; 464 buffer[pos++] = encodeTable[(x << 4) & MASK_6BITS]; 465 // URL-SAFE skips the padding to further reduce size. 466 if (encodeTable == STANDARD_ENCODE_TABLE) { 467 buffer[pos++] = PAD; 468 buffer[pos++] = PAD; 469 } 470 break; 471 472 case 2 : 473 buffer[pos++] = encodeTable[(x >> 10) & MASK_6BITS]; 474 buffer[pos++] = encodeTable[(x >> 4) & MASK_6BITS]; 475 buffer[pos++] = encodeTable[(x << 2) & MASK_6BITS]; 476 // URL-SAFE skips the padding to further reduce size. 477 if (encodeTable == STANDARD_ENCODE_TABLE) { 478 buffer[pos++] = PAD; 479 } 480 break; 481 } 482 if (lineLength > 0 && pos > 0) { 483 System.arraycopy(lineSeparator, 0, buffer, pos, lineSeparator.length); 484 pos += lineSeparator.length; 485 } 486 } else { 487 for (int i = 0; i < inAvail; i++) { 488 if (buffer == null || buffer.length - pos < encodeSize) { 489 resizeBuffer(); 490 } 491 modulus = (++modulus) % 3; 492 int b = in[inPos++]; 493 if (b < 0) { 494 b += 256; 495 } 496 x = (x << 8) + b; 497 if (0 == modulus) { 498 buffer[pos++] = encodeTable[(x >> 18) & MASK_6BITS]; 499 buffer[pos++] = encodeTable[(x >> 12) & MASK_6BITS]; 500 buffer[pos++] = encodeTable[(x >> 6) & MASK_6BITS]; 501 buffer[pos++] = encodeTable[x & MASK_6BITS]; 502 currentLinePos += 4; 503 if (lineLength > 0 && lineLength <= currentLinePos) { 504 System.arraycopy(lineSeparator, 0, buffer, pos, lineSeparator.length); 505 pos += lineSeparator.length; 506 currentLinePos = 0; 507 } 508 } 509 } 510 } 511 } 512 513 /** 514 * <p> 515 * Decodes all of the provided data, starting at inPos, for inAvail bytes. Should be called at least twice: once 516 * with the data to decode, and once with inAvail set to "-1" to alert decoder that EOF has been reached. The "-1" 517 * call is not necessary when decoding, but it doesn't hurt, either. 518 * </p> 519 * <p> 520 * Ignores all non-base64 characters. This is how chunked (e.g. 76 character) data is handled, since CR and LF are 521 * silently ignored, but has implications for other bytes, too. This method subscribes to the garbage-in, 522 * garbage-out philosophy: it will not check the provided data for validity. 523 * </p> 524 * <p> 525 * Thanks to "commons" project in ws.apache.org for the bitwise operations, and general approach. 526 * http://svn.apache.org/repos/asf/webservices/commons/trunk/modules/util/ 527 * </p> 528 * 529 * @param in 530 * byte[] array of ascii data to base64 decode. 531 * @param inPos 532 * Position to start reading data from. 533 * @param inAvail 534 * Amount of bytes available from input for encoding. 535 */ 536 void decode(byte[] in, int inPos, int inAvail) { 537 if (eof) { 538 return; 539 } 540 if (inAvail < 0) { 541 eof = true; 542 } 543 for (int i = 0; i < inAvail; i++) { 544 if (buffer == null || buffer.length - pos < decodeSize) { 545 resizeBuffer(); 546 } 547 byte b = in[inPos++]; 548 if (b == PAD) { 549 // We're done. 550 eof = true; 551 break; 552 } else { 553 if (b >= 0 && b < DECODE_TABLE.length) { 554 int result = DECODE_TABLE[b]; 555 if (result >= 0) { 556 modulus = (++modulus) % 4; 557 x = (x << 6) + result; 558 if (modulus == 0) { 559 buffer[pos++] = (byte) ((x >> 16) & MASK_8BITS); 560 buffer[pos++] = (byte) ((x >> 8) & MASK_8BITS); 561 buffer[pos++] = (byte) (x & MASK_8BITS); 562 } 563 } 564 } 565 } 566 } 567 568 // Two forms of EOF as far as base64 decoder is concerned: actual 569 // EOF (-1) and first time '=' character is encountered in stream. 570 // This approach makes the '=' padding characters completely optional. 571 if (eof && modulus != 0) { 572 x = x << 6; 573 switch (modulus) { 574 case 2 : 575 x = x << 6; 576 buffer[pos++] = (byte) ((x >> 16) & MASK_8BITS); 577 break; 578 case 3 : 579 buffer[pos++] = (byte) ((x >> 16) & MASK_8BITS); 580 buffer[pos++] = (byte) ((x >> 8) & MASK_8BITS); 581 break; 582 } 583 } 584 } 585 586 /** 587 * Returns whether or not the <code>octet</code> is in the base 64 alphabet. 588 * 589 * @param octet 590 * The value to test 591 * @return <code>true</code> if the value is defined in the the base 64 alphabet, <code>false</code> otherwise. 592 * @since 1.4 593 */ 594 public static boolean isBase64(byte octet) { 595 return octet == PAD || (octet >= 0 && octet < DECODE_TABLE.length && DECODE_TABLE[octet] != -1); 596 } 597 598 /** 599 * Tests a given byte array to see if it contains only valid characters within the Base64 alphabet. Currently the 600 * method treats whitespace as valid. 601 * 602 * @param arrayOctet 603 * byte array to test 604 * @return <code>true</code> if all bytes are valid characters in the Base64 alphabet or if the byte array is empty; 605 * false, otherwise 606 */ 607 public static boolean isArrayByteBase64(byte[] arrayOctet) { 608 for (int i = 0; i < arrayOctet.length; i++) { 609 if (!isBase64(arrayOctet[i]) && !isWhiteSpace(arrayOctet[i])) { 610 return false; 611 } 612 } 613 return true; 614 } 615 616 /** 617 * Tests a given byte array to see if it contains only valid characters within the Base64 alphabet. 618 * 619 * @param arrayOctet 620 * byte array to test 621 * @return <code>true</code> if any byte is a valid character in the Base64 alphabet; false herwise 622 */ 623 private static boolean containsBase64Byte(byte[] arrayOctet) { 624 for (int i = 0; i < arrayOctet.length; i++) { 625 if (isBase64(arrayOctet[i])) { 626 return true; 627 } 628 } 629 return false; 630 } 631 632 /** 633 * Encodes binary data using the base64 algorithm but does not chunk the output. 634 * 635 * @param binaryData 636 * binary data to encode 637 * @return byte[] containing Base64 characters in their UTF-8 representation. 638 */ 639 public static byte[] encodeBase64(byte[] binaryData) { 640 return encodeBase64(binaryData, false); 641 } 642 643 /** 644 * Encodes binary data using the base64 algorithm into 76 character blocks separated by CRLF. 645 * 646 * @param binaryData 647 * binary data to encode 648 * @return String containing Base64 characters. 649 * @since 1.4 650 */ 651 public static String encodeBase64String(byte[] binaryData) { 652 return newStringUtf8(encodeBase64(binaryData, true)); 653 } 654 655 /** 656 * Encodes binary data using a URL-safe variation of the base64 algorithm but does not chunk the output. The 657 * url-safe variation emits - and _ instead of + and / characters. 658 * 659 * @param binaryData 660 * binary data to encode 661 * @return byte[] containing Base64 characters in their UTF-8 representation. 662 * @since 1.4 663 */ 664 public static byte[] encodeBase64URLSafe(byte[] binaryData) { 665 return encodeBase64(binaryData, false, true); 666 } 667 668 /** 669 * Encodes binary data using a URL-safe variation of the base64 algorithm but does not chunk the output. The 670 * url-safe variation emits - and _ instead of + and / characters. 671 * 672 * @param binaryData 673 * binary data to encode 674 * @return String containing Base64 characters 675 * @since 1.4 676 */ 677 public static String encodeBase64URLSafeString(byte[] binaryData) { 678 return newStringUtf8(encodeBase64(binaryData, false, true)); 679 } 680 681 /** 682 * Encodes binary data using the base64 algorithm and chunks the encoded output into 76 character blocks 683 * 684 * @param binaryData 685 * binary data to encode 686 * @return Base64 characters chunked in 76 character blocks 687 */ 688 public static byte[] encodeBase64Chunked(byte[] binaryData) { 689 return encodeBase64(binaryData, true); 690 } 691 692 /** 693 * Decodes an Object using the base64 algorithm. This method is provided in order to satisfy the requirements of the 694 * Decoder interface, and will throw a DecoderException if the supplied object is not of type byte[] or String. 695 * 696 * @param pObject 697 * Object to decode 698 * @return An object (of type byte[]) containing the binary data which corresponds to the byte[] or String supplied. 699 * @throws RuntimeException 700 * if the parameter supplied is not of type byte[] 701 */ 702 public Object decode(Object pObject) { 703 if (pObject instanceof byte[]) { 704 return decode((byte[]) pObject); 705 } else if (pObject instanceof String) { 706 return decode((String) pObject); 707 } else { 708 throw new RuntimeException("Parameter supplied to Base64 decode is not a byte[] or a String"); 709 } 710 } 711 712 /** 713 * Decodes a String containing containing characters in the Base64 alphabet. 714 * 715 * @param pArray 716 * A String containing Base64 character data 717 * @return a byte array containing binary data 718 * @since 1.4 719 */ 720 public byte[] decode(String pArray) { 721 return decode(getBytesUtf8(pArray)); 722 } 723 724 private byte[] getBytesUtf8(String pArray) { 725 try { 726 return pArray.getBytes("UTF8"); 727 } catch (UnsupportedEncodingException e) { 728 throw new RuntimeException(e); 729 } 730 } 731 732 /** 733 * Decodes a byte[] containing containing characters in the Base64 alphabet. 734 * 735 * @param pArray 736 * A byte array containing Base64 character data 737 * @return a byte array containing binary data 738 */ 739 public byte[] decode(byte[] pArray) { 740 reset(); 741 if (pArray == null || pArray.length == 0) { 742 return pArray; 743 } 744 long len = (pArray.length * 3) / 4; 745 byte[] buf = new byte[(int) len]; 746 setInitialBuffer(buf, 0, buf.length); 747 decode(pArray, 0, pArray.length); 748 decode(pArray, 0, -1); // Notify decoder of EOF. 749 750 // Would be nice to just return buf (like we sometimes do in the encode 751 // logic), but we have no idea what the line-length was (could even be 752 // variable). So we cannot determine ahead of time exactly how big an 753 // array is necessary. Hence the need to construct a 2nd byte array to 754 // hold the final result: 755 756 byte[] result = new byte[pos]; 757 readResults(result, 0, result.length); 758 return result; 759 } 760 761 /** 762 * Encodes binary data using the base64 algorithm, optionally chunking the output into 76 character blocks. 763 * 764 * @param binaryData 765 * Array containing binary data to encode. 766 * @param isChunked 767 * if <code>true</code> this encoder will chunk the base64 output into 76 character blocks 768 * @return Base64-encoded data. 769 * @throws IllegalArgumentException 770 * Thrown when the input array needs an output array bigger than {@link Integer#MAX_VALUE} 771 */ 772 public static byte[] encodeBase64(byte[] binaryData, boolean isChunked) { 773 return encodeBase64(binaryData, isChunked, false); 774 } 775 776 /** 777 * Encodes binary data using the base64 algorithm, optionally chunking the output into 76 character blocks. 778 * 779 * @param binaryData 780 * Array containing binary data to encode. 781 * @param isChunked 782 * if <code>true</code> this encoder will chunk the base64 output into 76 character blocks 783 * @param urlSafe 784 * if <code>true</code> this encoder will emit - and _ instead of the usual + and / characters. 785 * @return Base64-encoded data. 786 * @throws IllegalArgumentException 787 * Thrown when the input array needs an output array bigger than {@link Integer#MAX_VALUE} 788 * @since 1.4 789 */ 790 public static byte[] encodeBase64(byte[] binaryData, boolean isChunked, boolean urlSafe) { 791 return encodeBase64(binaryData, isChunked, urlSafe, Integer.MAX_VALUE); 792 } 793 794 /** 795 * Encodes binary data using the base64 algorithm, optionally chunking the output into 76 character blocks. 796 * 797 * @param binaryData 798 * Array containing binary data to encode. 799 * @param isChunked 800 * if <code>true</code> this encoder will chunk the base64 output into 76 character blocks 801 * @param urlSafe 802 * if <code>true</code> this encoder will emit - and _ instead of the usual + and / characters. 803 * @param maxResultSize 804 * The maximum result size to accept. 805 * @return Base64-encoded data. 806 * @throws IllegalArgumentException 807 * Thrown when the input array needs an output array bigger than maxResultSize 808 * @since 1.4 809 */ 810 public static byte[] encodeBase64(byte[] binaryData, boolean isChunked, boolean urlSafe, int maxResultSize) { 811 if (binaryData == null || binaryData.length == 0) { 812 return binaryData; 813 } 814 815 long len = getEncodeLength(binaryData, CHUNK_SIZE, CHUNK_SEPARATOR); 816 if (len > maxResultSize) { 817 throw new IllegalArgumentException("Input array too big, the output array would be bigger (" + 818 len + 819 ") than the specified maxium size of " + 820 maxResultSize); 821 } 822 823 Base64 b64 = isChunked ? new Base64(urlSafe) : new Base64(0, CHUNK_SEPARATOR, urlSafe); 824 return b64.encode(binaryData); 825 } 826 827 /** 828 * Decodes a Base64 String into octets 829 * 830 * @param base64String 831 * String containing Base64 data 832 * @return Array containing decoded data. 833 * @since 1.4 834 */ 835 public static byte[] decodeBase64(String base64String) { 836 return new Base64().decode(base64String); 837 } 838 839 /** 840 * Decodes Base64 data into octets 841 * 842 * @param base64Data 843 * Byte array containing Base64 data 844 * @return Array containing decoded data. 845 */ 846 public static byte[] decodeBase64(byte[] base64Data) { 847 return new Base64().decode(base64Data); 848 } 849 850 851 852 /** 853 * Checks if a byte value is whitespace or not. 854 * 855 * @param byteToCheck 856 * the byte to check 857 * @return true if byte is whitespace, false otherwise 858 */ 859 private static boolean isWhiteSpace(byte byteToCheck) { 860 switch (byteToCheck) { 861 case ' ' : 862 case '\n' : 863 case '\r' : 864 case '\t' : 865 return true; 866 default : 867 return false; 868 } 869 } 870 871 // Implementation of the Encoder Interface 872 873 /** 874 * Encodes an Object using the base64 algorithm. This method is provided in order to satisfy the requirements of the 875 * Encoder interface, and will throw an EncoderException if the supplied object is not of type byte[]. 876 * 877 * @param pObject 878 * Object to encode 879 * @return An object (of type byte[]) containing the base64 encoded data which corresponds to the byte[] supplied. 880 * @throws RuntimeException 881 * if the parameter supplied is not of type byte[] 882 */ 883 public Object encode(Object pObject) { 884 if (!(pObject instanceof byte[])) { 885 throw new RuntimeException("Parameter supplied to Base64 encode is not a byte[]"); 886 } 887 return encode((byte[]) pObject); 888 } 889 890 /** 891 * Encodes a byte[] containing binary data, into a String containing characters in the Base64 alphabet. 892 * 893 * @param pArray 894 * a byte array containing binary data 895 * @return A String containing only Base64 character data 896 * @since 1.4 897 */ 898 public String encodeToString(byte[] pArray) { 899 return newStringUtf8(encode(pArray)); 900 } 901 902 private static String newStringUtf8(byte[] encode) { 903 String str = null; 904 try { 905 str = new String(encode, "UTF8"); 906 } catch (UnsupportedEncodingException ue) { 907 throw new RuntimeException(ue); 908 } 909 return str; 910 } 911 912 /** 913 * Encodes a byte[] containing binary data, into a byte[] containing characters in the Base64 alphabet. 914 * 915 * @param pArray 916 * a byte array containing binary data 917 * @return A byte array containing only Base64 character data 918 */ 919 public byte[] encode(byte[] pArray) { 920 reset(); 921 if (pArray == null || pArray.length == 0) { 922 return pArray; 923 } 924 long len = getEncodeLength(pArray, lineLength, lineSeparator); 925 byte[] buf = new byte[(int) len]; 926 setInitialBuffer(buf, 0, buf.length); 927 encode(pArray, 0, pArray.length); 928 encode(pArray, 0, -1); // Notify encoder of EOF. 929 // Encoder might have resized, even though it was unnecessary. 930 if (buffer != buf) { 931 readResults(buf, 0, buf.length); 932 } 933 // In URL-SAFE mode we skip the padding characters, so sometimes our 934 // final length is a bit smaller. 935 if (isUrlSafe() && pos < buf.length) { 936 byte[] smallerBuf = new byte[pos]; 937 System.arraycopy(buf, 0, smallerBuf, 0, pos); 938 buf = smallerBuf; 939 } 940 return buf; 941 } 942 943 /** 944 * Pre-calculates the amount of space needed to base64-encode the supplied array. 945 * 946 * @param pArray byte[] array which will later be encoded 947 * @param chunkSize line-length of the output (<= 0 means no chunking) between each 948 * chunkSeparator (e.g. CRLF). 949 * @param chunkSeparator the sequence of bytes used to separate chunks of output (e.g. CRLF). 950 * 951 * @return amount of space needed to encoded the supplied array. Returns 952 * a long since a max-len array will require Integer.MAX_VALUE + 33%. 953 */ 954 private static long getEncodeLength(byte[] pArray, int chunkSize, byte[] chunkSeparator) { 955 // base64 always encodes to multiples of 4. 956 chunkSize = (chunkSize / 4) * 4; 957 958 long len = (pArray.length * 4) / 3; 959 long mod = len % 4; 960 if (mod != 0) { 961 len += 4 - mod; 962 } 963 if (chunkSize > 0) { 964 boolean lenChunksPerfectly = len % chunkSize == 0; 965 len += (len / chunkSize) * chunkSeparator.length; 966 if (!lenChunksPerfectly) { 967 len += chunkSeparator.length; 968 } 969 } 970 return len; 971 } 972 973 // Implementation of integer encoding used for crypto 974 /** 975 * Decodes a byte64-encoded integer according to crypto standards such as W3C's XML-Signature 976 * 977 * @param pArray 978 * a byte array containing base64 character data 979 * @return A BigInteger 980 * @since 1.4 981 */ 982 public static BigInteger decodeInteger(byte[] pArray) { 983 return new BigInteger(1, decodeBase64(pArray)); 984 } 985 986 /** 987 * Encodes to a byte64-encoded integer according to crypto standards such as W3C's XML-Signature 988 * 989 * @param bigInt 990 * a BigInteger 991 * @return A byte array containing base64 character data 992 * @throws NullPointerException 993 * if null is passed in 994 * @since 1.4 995 */ 996 public static byte[] encodeInteger(BigInteger bigInt) { 997 if (bigInt == null) { 998 throw new NullPointerException("encodeInteger called with null parameter"); 999 } 1000 return encodeBase64(toIntegerBytes(bigInt), false); 1001 } 1002 1003 /** 1004 * Returns a byte-array representation of a <code>BigInteger</code> without sign bit. 1005 * 1006 * @param bigInt 1007 * <code>BigInteger</code> to be converted 1008 * @return a byte array representation of the BigInteger parameter 1009 */ 1010 static byte[] toIntegerBytes(BigInteger bigInt) { 1011 int bitlen = bigInt.bitLength(); 1012 // round bitlen 1013 bitlen = ((bitlen + 7) >> 3) << 3; 1014 byte[] bigBytes = bigInt.toByteArray(); 1015 1016 if (((bigInt.bitLength() % 8) != 0) && (((bigInt.bitLength() / 8) + 1) == (bitlen / 8))) { 1017 return bigBytes; 1018 } 1019 // set up params for copying everything but sign bit 1020 int startSrc = 0; 1021 int len = bigBytes.length; 1022 1023 // if bigInt is exactly byte-aligned, just skip signbit in copy 1024 if ((bigInt.bitLength() % 8) == 0) { 1025 startSrc = 1; 1026 len--; 1027 } 1028 int startDst = bitlen / 8 - len; // to pad w/ nulls as per spec 1029 byte[] resizedBytes = new byte[bitlen / 8]; 1030 System.arraycopy(bigBytes, startSrc, resizedBytes, startDst, len); 1031 return resizedBytes; 1032 } 1033 1034 /** 1035 * Resets this Base64 object to its initial newly constructed state. 1036 */ 1037 private void reset() { 1038 buffer = null; 1039 pos = 0; 1040 readPos = 0; 1041 currentLinePos = 0; 1042 modulus = 0; 1043 eof = false; 1044 } 1045 1046 }