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.codec.binary; 019 020 import java.math.BigInteger; 021 022 /** 023 * Provides Base64 encoding and decoding as defined by <a href="http://www.ietf.org/rfc/rfc2045.txt">RFC 2045</a>. 024 * 025 * <p> 026 * This class implements section <cite>6.8. Base64 Content-Transfer-Encoding</cite> from RFC 2045 <cite>Multipurpose 027 * Internet Mail Extensions (MIME) Part One: Format of Internet Message Bodies</cite> by Freed and Borenstein. 028 * </p> 029 * <p> 030 * The class can be parameterized in the following manner with various constructors: 031 * <ul> 032 * <li>URL-safe mode: Default off.</li> 033 * <li>Line length: Default 76. Line length that aren't multiples of 4 will still essentially end up being multiples of 034 * 4 in the encoded data. 035 * <li>Line separator: Default is CRLF ("\r\n")</li> 036 * </ul> 037 * </p> 038 * <p> 039 * Since this class operates directly on byte streams, and not character streams, it is hard-coded to only 040 * encode/decode character encodings which are compatible with the lower 127 ASCII chart (ISO-8859-1, Windows-1252, 041 * UTF-8, etc). 042 * </p> 043 * <p> 044 * This class is thread-safe. 045 * </p> 046 * 047 * @see <a href="http://www.ietf.org/rfc/rfc2045.txt">RFC 2045</a> 048 * @since 1.0 049 * @version $Id: Base64.html 889935 2013-12-11 05:05:13Z ggregory $ 050 */ 051 public class Base64 extends BaseNCodec { 052 053 /** 054 * BASE32 characters are 6 bits in length. 055 * They are formed by taking a block of 3 octets to form a 24-bit string, 056 * which is converted into 4 BASE64 characters. 057 */ 058 private static final int BITS_PER_ENCODED_BYTE = 6; 059 private static final int BYTES_PER_UNENCODED_BLOCK = 3; 060 private static final int BYTES_PER_ENCODED_BLOCK = 4; 061 062 /** 063 * Chunk separator per RFC 2045 section 2.1. 064 * 065 * <p> 066 * N.B. The next major release may break compatibility and make this field private. 067 * </p> 068 * 069 * @see <a href="http://www.ietf.org/rfc/rfc2045.txt">RFC 2045 section 2.1</a> 070 */ 071 static final byte[] CHUNK_SEPARATOR = {'\r', '\n'}; 072 073 /** 074 * This array is a lookup table that translates 6-bit positive integer index values into their "Base64 Alphabet" 075 * equivalents as specified in Table 1 of RFC 2045. 076 * 077 * Thanks to "commons" project in ws.apache.org for this code. 078 * http://svn.apache.org/repos/asf/webservices/commons/trunk/modules/util/ 079 */ 080 private static final byte[] STANDARD_ENCODE_TABLE = { 081 'A', 'B', 'C', 'D', 'E', 'F', 'G', 'H', 'I', 'J', 'K', 'L', 'M', 082 'N', 'O', 'P', 'Q', 'R', 'S', 'T', 'U', 'V', 'W', 'X', 'Y', 'Z', 083 'a', 'b', 'c', 'd', 'e', 'f', 'g', 'h', 'i', 'j', 'k', 'l', 'm', 084 'n', 'o', 'p', 'q', 'r', 's', 't', 'u', 'v', 'w', 'x', 'y', 'z', 085 '0', '1', '2', '3', '4', '5', '6', '7', '8', '9', '+', '/' 086 }; 087 088 /** 089 * This is a copy of the STANDARD_ENCODE_TABLE above, but with + and / 090 * changed to - and _ to make the encoded Base64 results more URL-SAFE. 091 * This table is only used when the Base64's mode is set to URL-SAFE. 092 */ 093 private static final byte[] URL_SAFE_ENCODE_TABLE = { 094 'A', 'B', 'C', 'D', 'E', 'F', 'G', 'H', 'I', 'J', 'K', 'L', 'M', 095 'N', 'O', 'P', 'Q', 'R', 'S', 'T', 'U', 'V', 'W', 'X', 'Y', 'Z', 096 'a', 'b', 'c', 'd', 'e', 'f', 'g', 'h', 'i', 'j', 'k', 'l', 'm', 097 'n', 'o', 'p', 'q', 'r', 's', 't', 'u', 'v', 'w', 'x', 'y', 'z', 098 '0', '1', '2', '3', '4', '5', '6', '7', '8', '9', '-', '_' 099 }; 100 101 /** 102 * This array is a lookup table that translates Unicode characters drawn from the "Base64 Alphabet" (as specified 103 * in Table 1 of RFC 2045) into their 6-bit positive integer equivalents. Characters that are not in the Base64 104 * alphabet but fall within the bounds of the array are translated to -1. 105 * 106 * Note: '+' and '-' both decode to 62. '/' and '_' both decode to 63. This means decoder seamlessly handles both 107 * URL_SAFE and STANDARD base64. (The encoder, on the other hand, needs to know ahead of time what to emit). 108 * 109 * Thanks to "commons" project in ws.apache.org for this code. 110 * http://svn.apache.org/repos/asf/webservices/commons/trunk/modules/util/ 111 */ 112 private static final byte[] DECODE_TABLE = { 113 -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, 114 -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, 115 -1, -1, -1, -1, -1, -1, -1, -1, -1, 62, -1, 62, -1, 63, 52, 53, 54, 116 55, 56, 57, 58, 59, 60, 61, -1, -1, -1, -1, -1, -1, -1, 0, 1, 2, 3, 4, 117 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 118 24, 25, -1, -1, -1, -1, 63, -1, 26, 27, 28, 29, 30, 31, 32, 33, 34, 119 35, 36, 37, 38, 39, 40, 41, 42, 43, 44, 45, 46, 47, 48, 49, 50, 51 120 }; 121 122 /** 123 * Base64 uses 6-bit fields. 124 */ 125 /** Mask used to extract 6 bits, used when encoding */ 126 private static final int MASK_6BITS = 0x3f; 127 128 // The static final fields above are used for the original static byte[] methods on Base64. 129 // The private member fields below are used with the new streaming approach, which requires 130 // some state be preserved between calls of encode() and decode(). 131 132 /** 133 * Encode table to use: either STANDARD or URL_SAFE. Note: the DECODE_TABLE above remains static because it is able 134 * to decode both STANDARD and URL_SAFE streams, but the encodeTable must be a member variable so we can switch 135 * between the two modes. 136 */ 137 private final byte[] encodeTable; 138 139 // Only one decode table currently; keep for consistency with Base32 code 140 private final byte[] decodeTable = DECODE_TABLE; 141 142 /** 143 * Line separator for encoding. Not used when decoding. Only used if lineLength > 0. 144 */ 145 private final byte[] lineSeparator; 146 147 /** 148 * Convenience variable to help us determine when our buffer is going to run out of room and needs resizing. 149 * <code>decodeSize = 3 + lineSeparator.length;</code> 150 */ 151 private final int decodeSize; 152 153 /** 154 * Convenience variable to help us determine when our buffer is going to run out of room and needs resizing. 155 * <code>encodeSize = 4 + lineSeparator.length;</code> 156 */ 157 private final int encodeSize; 158 159 /** 160 * Creates a Base64 codec used for decoding (all modes) and encoding in URL-unsafe mode. 161 * <p> 162 * When encoding the line length is 0 (no chunking), and the encoding table is STANDARD_ENCODE_TABLE. 163 * </p> 164 * 165 * <p> 166 * When decoding all variants are supported. 167 * </p> 168 */ 169 public Base64() { 170 this(0); 171 } 172 173 /** 174 * Creates a Base64 codec used for decoding (all modes) and encoding in the given URL-safe mode. 175 * <p> 176 * When encoding the line length is 76, the line separator is CRLF, and the encoding table is 177 * STANDARD_ENCODE_TABLE. 178 * </p> 179 * 180 * <p> 181 * When decoding all variants are supported. 182 * </p> 183 * 184 * @param urlSafe 185 * if {@code true}, URL-safe encoding is used. In most cases this should be set to {@code false}. 186 * @since 1.4 187 */ 188 public Base64(boolean urlSafe) { 189 this(MIME_CHUNK_SIZE, CHUNK_SEPARATOR, urlSafe); 190 } 191 192 /** 193 * Creates a Base64 codec used for decoding (all modes) and encoding in URL-unsafe mode. 194 * <p> 195 * When encoding the line length is given in the constructor, the line separator is CRLF, and the encoding table is 196 * STANDARD_ENCODE_TABLE. 197 * </p> 198 * <p> 199 * Line lengths that aren't multiples of 4 will still essentially end up being multiples of 4 in the encoded data. 200 * </p> 201 * <p> 202 * When decoding all variants are supported. 203 * </p> 204 * 205 * @param lineLength 206 * Each line of encoded data will be at most of the given length (rounded down to nearest multiple of 207 * 4). If lineLength <= 0, then the output will not be divided into lines (chunks). Ignored when 208 * decoding. 209 * @since 1.4 210 */ 211 public Base64(int lineLength) { 212 this(lineLength, CHUNK_SEPARATOR); 213 } 214 215 /** 216 * Creates a Base64 codec used for decoding (all modes) and encoding in URL-unsafe mode. 217 * <p> 218 * When encoding the line length and line separator are given in the constructor, and the encoding table is 219 * STANDARD_ENCODE_TABLE. 220 * </p> 221 * <p> 222 * Line lengths that aren't multiples of 4 will still essentially end up being multiples of 4 in the encoded data. 223 * </p> 224 * <p> 225 * When decoding all variants are supported. 226 * </p> 227 * 228 * @param lineLength 229 * Each line of encoded data will be at most of the given length (rounded down to nearest multiple of 230 * 4). If lineLength <= 0, then the output will not be divided into lines (chunks). Ignored when 231 * decoding. 232 * @param lineSeparator 233 * Each line of encoded data will end with this sequence of bytes. 234 * @throws IllegalArgumentException 235 * Thrown when the provided lineSeparator included some base64 characters. 236 * @since 1.4 237 */ 238 public Base64(int lineLength, byte[] lineSeparator) { 239 this(lineLength, lineSeparator, false); 240 } 241 242 /** 243 * Creates a Base64 codec used for decoding (all modes) and encoding in URL-unsafe mode. 244 * <p> 245 * When encoding the line length and line separator are given in the constructor, and the encoding table is 246 * STANDARD_ENCODE_TABLE. 247 * </p> 248 * <p> 249 * Line lengths that aren't multiples of 4 will still essentially end up being multiples of 4 in the encoded data. 250 * </p> 251 * <p> 252 * When decoding all variants are supported. 253 * </p> 254 * 255 * @param lineLength 256 * Each line of encoded data will be at most of the given length (rounded down to nearest multiple of 257 * 4). If lineLength <= 0, then the output will not be divided into lines (chunks). Ignored when 258 * decoding. 259 * @param lineSeparator 260 * Each line of encoded data will end with this sequence of bytes. 261 * @param urlSafe 262 * Instead of emitting '+' and '/' we emit '-' and '_' respectively. urlSafe is only applied to encode 263 * operations. Decoding seamlessly handles both modes. 264 * @throws IllegalArgumentException 265 * The provided lineSeparator included some base64 characters. That's not going to work! 266 * @since 1.4 267 */ 268 public Base64(int lineLength, byte[] lineSeparator, boolean urlSafe) { 269 super(BYTES_PER_UNENCODED_BLOCK, BYTES_PER_ENCODED_BLOCK, 270 lineLength, 271 lineSeparator == null ? 0 : lineSeparator.length); 272 // TODO could be simplified if there is no requirement to reject invalid line sep when length <=0 273 // @see test case Base64Test.testConstructors() 274 if (lineSeparator != null) { 275 if (containsAlphabetOrPad(lineSeparator)) { 276 String sep = StringUtils.newStringUtf8(lineSeparator); 277 throw new IllegalArgumentException("lineSeparator must not contain base64 characters: [" + sep + "]"); 278 } 279 if (lineLength > 0){ // null line-sep forces no chunking rather than throwing IAE 280 this.encodeSize = BYTES_PER_ENCODED_BLOCK + lineSeparator.length; 281 this.lineSeparator = new byte[lineSeparator.length]; 282 System.arraycopy(lineSeparator, 0, this.lineSeparator, 0, lineSeparator.length); 283 } else { 284 this.encodeSize = BYTES_PER_ENCODED_BLOCK; 285 this.lineSeparator = null; 286 } 287 } else { 288 this.encodeSize = BYTES_PER_ENCODED_BLOCK; 289 this.lineSeparator = null; 290 } 291 this.decodeSize = this.encodeSize - 1; 292 this.encodeTable = urlSafe ? URL_SAFE_ENCODE_TABLE : STANDARD_ENCODE_TABLE; 293 } 294 295 /** 296 * Returns our current encode mode. True if we're URL-SAFE, false otherwise. 297 * 298 * @return true if we're in URL-SAFE mode, false otherwise. 299 * @since 1.4 300 */ 301 public boolean isUrlSafe() { 302 return this.encodeTable == URL_SAFE_ENCODE_TABLE; 303 } 304 305 /** 306 * <p> 307 * Encodes all of the provided data, starting at inPos, for inAvail bytes. Must be called at least twice: once with 308 * the data to encode, and once with inAvail set to "-1" to alert encoder that EOF has been reached, so flush last 309 * remaining bytes (if not multiple of 3). 310 * </p> 311 * <p> 312 * Thanks to "commons" project in ws.apache.org for the bitwise operations, and general approach. 313 * http://svn.apache.org/repos/asf/webservices/commons/trunk/modules/util/ 314 * </p> 315 * 316 * @param in 317 * byte[] array of binary data to base64 encode. 318 * @param inPos 319 * Position to start reading data from. 320 * @param inAvail 321 * Amount of bytes available from input for encoding. 322 * @param context 323 * the context to be used 324 */ 325 @Override 326 void encode(byte[] in, int inPos, int inAvail, Context context) { 327 if (context.eof) { 328 return; 329 } 330 // inAvail < 0 is how we're informed of EOF in the underlying data we're 331 // encoding. 332 if (inAvail < 0) { 333 context.eof = true; 334 if (0 == context.modulus && lineLength == 0) { 335 return; // no leftovers to process and not using chunking 336 } 337 final byte[] buffer = ensureBufferSize(encodeSize, context); 338 final int savedPos = context.pos; 339 switch (context.modulus) { // 0-2 340 case 0 : // nothing to do here 341 break; 342 case 1 : // 8 bits = 6 + 2 343 // top 6 bits: 344 buffer[context.pos++] = encodeTable[(context.ibitWorkArea >> 2) & MASK_6BITS]; 345 // remaining 2: 346 buffer[context.pos++] = encodeTable[(context.ibitWorkArea << 4) & MASK_6BITS]; 347 // URL-SAFE skips the padding to further reduce size. 348 if (encodeTable == STANDARD_ENCODE_TABLE) { 349 buffer[context.pos++] = PAD; 350 buffer[context.pos++] = PAD; 351 } 352 break; 353 354 case 2 : // 16 bits = 6 + 6 + 4 355 buffer[context.pos++] = encodeTable[(context.ibitWorkArea >> 10) & MASK_6BITS]; 356 buffer[context.pos++] = encodeTable[(context.ibitWorkArea >> 4) & MASK_6BITS]; 357 buffer[context.pos++] = encodeTable[(context.ibitWorkArea << 2) & MASK_6BITS]; 358 // URL-SAFE skips the padding to further reduce size. 359 if (encodeTable == STANDARD_ENCODE_TABLE) { 360 buffer[context.pos++] = PAD; 361 } 362 break; 363 default: 364 throw new IllegalStateException("Impossible modulus "+context.modulus); 365 } 366 context.currentLinePos += context.pos - savedPos; // keep track of current line position 367 // if currentPos == 0 we are at the start of a line, so don't add CRLF 368 if (lineLength > 0 && context.currentLinePos > 0) { 369 System.arraycopy(lineSeparator, 0, buffer, context.pos, lineSeparator.length); 370 context.pos += lineSeparator.length; 371 } 372 } else { 373 for (int i = 0; i < inAvail; i++) { 374 final byte[] buffer = ensureBufferSize(encodeSize, context); 375 context.modulus = (context.modulus+1) % BYTES_PER_UNENCODED_BLOCK; 376 int b = in[inPos++]; 377 if (b < 0) { 378 b += 256; 379 } 380 context.ibitWorkArea = (context.ibitWorkArea << 8) + b; // BITS_PER_BYTE 381 if (0 == context.modulus) { // 3 bytes = 24 bits = 4 * 6 bits to extract 382 buffer[context.pos++] = encodeTable[(context.ibitWorkArea >> 18) & MASK_6BITS]; 383 buffer[context.pos++] = encodeTable[(context.ibitWorkArea >> 12) & MASK_6BITS]; 384 buffer[context.pos++] = encodeTable[(context.ibitWorkArea >> 6) & MASK_6BITS]; 385 buffer[context.pos++] = encodeTable[context.ibitWorkArea & MASK_6BITS]; 386 context.currentLinePos += BYTES_PER_ENCODED_BLOCK; 387 if (lineLength > 0 && lineLength <= context.currentLinePos) { 388 System.arraycopy(lineSeparator, 0, buffer, context.pos, lineSeparator.length); 389 context.pos += lineSeparator.length; 390 context.currentLinePos = 0; 391 } 392 } 393 } 394 } 395 } 396 397 /** 398 * <p> 399 * Decodes all of the provided data, starting at inPos, for inAvail bytes. Should be called at least twice: once 400 * with the data to decode, and once with inAvail set to "-1" to alert decoder that EOF has been reached. The "-1" 401 * call is not necessary when decoding, but it doesn't hurt, either. 402 * </p> 403 * <p> 404 * Ignores all non-base64 characters. This is how chunked (e.g. 76 character) data is handled, since CR and LF are 405 * silently ignored, but has implications for other bytes, too. This method subscribes to the garbage-in, 406 * garbage-out philosophy: it will not check the provided data for validity. 407 * </p> 408 * <p> 409 * Thanks to "commons" project in ws.apache.org for the bitwise operations, and general approach. 410 * http://svn.apache.org/repos/asf/webservices/commons/trunk/modules/util/ 411 * </p> 412 * 413 * @param in 414 * byte[] array of ascii data to base64 decode. 415 * @param inPos 416 * Position to start reading data from. 417 * @param inAvail 418 * Amount of bytes available from input for encoding. 419 * @param context 420 * the context to be used 421 */ 422 @Override 423 void decode(byte[] in, int inPos, int inAvail, Context context) { 424 if (context.eof) { 425 return; 426 } 427 if (inAvail < 0) { 428 context.eof = true; 429 } 430 for (int i = 0; i < inAvail; i++) { 431 final byte[] buffer = ensureBufferSize(decodeSize, context); 432 final byte b = in[inPos++]; 433 if (b == PAD) { 434 // We're done. 435 context.eof = true; 436 break; 437 } else { 438 if (b >= 0 && b < DECODE_TABLE.length) { 439 final int result = DECODE_TABLE[b]; 440 if (result >= 0) { 441 context.modulus = (context.modulus+1) % BYTES_PER_ENCODED_BLOCK; 442 context.ibitWorkArea = (context.ibitWorkArea << BITS_PER_ENCODED_BYTE) + result; 443 if (context.modulus == 0) { 444 buffer[context.pos++] = (byte) ((context.ibitWorkArea >> 16) & MASK_8BITS); 445 buffer[context.pos++] = (byte) ((context.ibitWorkArea >> 8) & MASK_8BITS); 446 buffer[context.pos++] = (byte) (context.ibitWorkArea & MASK_8BITS); 447 } 448 } 449 } 450 } 451 } 452 453 // Two forms of EOF as far as base64 decoder is concerned: actual 454 // EOF (-1) and first time '=' character is encountered in stream. 455 // This approach makes the '=' padding characters completely optional. 456 if (context.eof && context.modulus != 0) { 457 final byte[] buffer = ensureBufferSize(decodeSize, context); 458 459 // We have some spare bits remaining 460 // Output all whole multiples of 8 bits and ignore the rest 461 switch (context.modulus) { 462 // case 0 : // impossible, as excluded above 463 case 1 : // 6 bits - ignore entirely 464 // TODO not currently tested; perhaps it is impossible? 465 break; 466 case 2 : // 12 bits = 8 + 4 467 context.ibitWorkArea = context.ibitWorkArea >> 4; // dump the extra 4 bits 468 buffer[context.pos++] = (byte) ((context.ibitWorkArea) & MASK_8BITS); 469 break; 470 case 3 : // 18 bits = 8 + 8 + 2 471 context.ibitWorkArea = context.ibitWorkArea >> 2; // dump 2 bits 472 buffer[context.pos++] = (byte) ((context.ibitWorkArea >> 8) & MASK_8BITS); 473 buffer[context.pos++] = (byte) ((context.ibitWorkArea) & MASK_8BITS); 474 break; 475 default: 476 throw new IllegalStateException("Impossible modulus "+context.modulus); 477 } 478 } 479 } 480 481 /** 482 * Tests a given byte array to see if it contains only valid characters within the Base64 alphabet. Currently the 483 * method treats whitespace as valid. 484 * 485 * @param arrayOctet 486 * byte array to test 487 * @return {@code true} if all bytes are valid characters in the Base64 alphabet or if the byte array is empty; 488 * {@code false}, otherwise 489 * @deprecated 1.5 Use {@link #isBase64(byte[])}, will be removed in 2.0. 490 */ 491 @Deprecated 492 public static boolean isArrayByteBase64(byte[] arrayOctet) { 493 return isBase64(arrayOctet); 494 } 495 496 /** 497 * Returns whether or not the <code>octet</code> is in the base 64 alphabet. 498 * 499 * @param octet 500 * The value to test 501 * @return {@code true} if the value is defined in the the base 64 alphabet, {@code false} otherwise. 502 * @since 1.4 503 */ 504 public static boolean isBase64(byte octet) { 505 return octet == PAD_DEFAULT || (octet >= 0 && octet < DECODE_TABLE.length && DECODE_TABLE[octet] != -1); 506 } 507 508 /** 509 * Tests a given String to see if it contains only valid characters within the Base64 alphabet. Currently the 510 * method treats whitespace as valid. 511 * 512 * @param base64 513 * String to test 514 * @return {@code true} if all characters in the String are valid characters in the Base64 alphabet or if 515 * the String is empty; {@code false}, otherwise 516 * @since 1.5 517 */ 518 public static boolean isBase64(String base64) { 519 return isBase64(StringUtils.getBytesUtf8(base64)); 520 } 521 522 /** 523 * Tests a given byte array to see if it contains only valid characters within the Base64 alphabet. Currently the 524 * method treats whitespace as valid. 525 * 526 * @param arrayOctet 527 * byte array to test 528 * @return {@code true} if all bytes are valid characters in the Base64 alphabet or if the byte array is empty; 529 * {@code false}, otherwise 530 * @since 1.5 531 */ 532 public static boolean isBase64(byte[] arrayOctet) { 533 for (int i = 0; i < arrayOctet.length; i++) { 534 if (!isBase64(arrayOctet[i]) && !isWhiteSpace(arrayOctet[i])) { 535 return false; 536 } 537 } 538 return true; 539 } 540 541 /** 542 * Encodes binary data using the base64 algorithm but does not chunk the output. 543 * 544 * @param binaryData 545 * binary data to encode 546 * @return byte[] containing Base64 characters in their UTF-8 representation. 547 */ 548 public static byte[] encodeBase64(byte[] binaryData) { 549 return encodeBase64(binaryData, false); 550 } 551 552 /** 553 * Encodes binary data using the base64 algorithm but does not chunk the output. 554 * 555 * NOTE: We changed the behaviour of this method from multi-line chunking (commons-codec-1.4) to 556 * single-line non-chunking (commons-codec-1.5). 557 * 558 * @param binaryData 559 * binary data to encode 560 * @return String containing Base64 characters. 561 * @since 1.4 (NOTE: 1.4 chunked the output, whereas 1.5 does not). 562 */ 563 public static String encodeBase64String(byte[] binaryData) { 564 return StringUtils.newStringUtf8(encodeBase64(binaryData, false)); 565 } 566 567 /** 568 * Encodes binary data using a URL-safe variation of the base64 algorithm but does not chunk the output. The 569 * url-safe variation emits - and _ instead of + and / characters. 570 * 571 * @param binaryData 572 * binary data to encode 573 * @return byte[] containing Base64 characters in their UTF-8 representation. 574 * @since 1.4 575 */ 576 public static byte[] encodeBase64URLSafe(byte[] binaryData) { 577 return encodeBase64(binaryData, false, true); 578 } 579 580 /** 581 * Encodes binary data using a URL-safe variation of the base64 algorithm but does not chunk the output. The 582 * url-safe variation emits - and _ instead of + and / characters. 583 * 584 * @param binaryData 585 * binary data to encode 586 * @return String containing Base64 characters 587 * @since 1.4 588 */ 589 public static String encodeBase64URLSafeString(byte[] binaryData) { 590 return StringUtils.newStringUtf8(encodeBase64(binaryData, false, true)); 591 } 592 593 /** 594 * Encodes binary data using the base64 algorithm and chunks the encoded output into 76 character blocks 595 * 596 * @param binaryData 597 * binary data to encode 598 * @return Base64 characters chunked in 76 character blocks 599 */ 600 public static byte[] encodeBase64Chunked(byte[] binaryData) { 601 return encodeBase64(binaryData, true); 602 } 603 604 /** 605 * Encodes binary data using the base64 algorithm, optionally chunking the output into 76 character blocks. 606 * 607 * @param binaryData 608 * Array containing binary data to encode. 609 * @param isChunked 610 * if {@code true} this encoder will chunk the base64 output into 76 character blocks 611 * @return Base64-encoded data. 612 * @throws IllegalArgumentException 613 * Thrown when the input array needs an output array bigger than {@link Integer#MAX_VALUE} 614 */ 615 public static byte[] encodeBase64(byte[] binaryData, boolean isChunked) { 616 return encodeBase64(binaryData, isChunked, false); 617 } 618 619 /** 620 * Encodes binary data using the base64 algorithm, optionally chunking the output into 76 character blocks. 621 * 622 * @param binaryData 623 * Array containing binary data to encode. 624 * @param isChunked 625 * if {@code true} this encoder will chunk the base64 output into 76 character blocks 626 * @param urlSafe 627 * if {@code true} this encoder will emit - and _ instead of the usual + and / characters. 628 * @return Base64-encoded data. 629 * @throws IllegalArgumentException 630 * Thrown when the input array needs an output array bigger than {@link Integer#MAX_VALUE} 631 * @since 1.4 632 */ 633 public static byte[] encodeBase64(byte[] binaryData, boolean isChunked, boolean urlSafe) { 634 return encodeBase64(binaryData, isChunked, urlSafe, Integer.MAX_VALUE); 635 } 636 637 /** 638 * Encodes binary data using the base64 algorithm, optionally chunking the output into 76 character blocks. 639 * 640 * @param binaryData 641 * Array containing binary data to encode. 642 * @param isChunked 643 * if {@code true} this encoder will chunk the base64 output into 76 character blocks 644 * @param urlSafe 645 * if {@code true} this encoder will emit - and _ instead of the usual + and / characters. 646 * @param maxResultSize 647 * The maximum result size to accept. 648 * @return Base64-encoded data. 649 * @throws IllegalArgumentException 650 * Thrown when the input array needs an output array bigger than maxResultSize 651 * @since 1.4 652 */ 653 public static byte[] encodeBase64(byte[] binaryData, boolean isChunked, boolean urlSafe, int maxResultSize) { 654 if (binaryData == null || binaryData.length == 0) { 655 return binaryData; 656 } 657 658 // Create this so can use the super-class method 659 // Also ensures that the same roundings are performed by the ctor and the code 660 Base64 b64 = isChunked ? new Base64(urlSafe) : new Base64(0, CHUNK_SEPARATOR, urlSafe); 661 long len = b64.getEncodedLength(binaryData); 662 if (len > maxResultSize) { 663 throw new IllegalArgumentException("Input array too big, the output array would be bigger (" + 664 len + 665 ") than the specified maximum size of " + 666 maxResultSize); 667 } 668 669 return b64.encode(binaryData); 670 } 671 672 /** 673 * Decodes a Base64 String into octets 674 * 675 * @param base64String 676 * String containing Base64 data 677 * @return Array containing decoded data. 678 * @since 1.4 679 */ 680 public static byte[] decodeBase64(String base64String) { 681 return new Base64().decode(base64String); 682 } 683 684 /** 685 * Decodes Base64 data into octets 686 * 687 * @param base64Data 688 * Byte array containing Base64 data 689 * @return Array containing decoded data. 690 */ 691 public static byte[] decodeBase64(byte[] base64Data) { 692 return new Base64().decode(base64Data); 693 } 694 695 // Implementation of the Encoder Interface 696 697 // Implementation of integer encoding used for crypto 698 /** 699 * Decodes a byte64-encoded integer according to crypto standards such as W3C's XML-Signature 700 * 701 * @param pArray 702 * a byte array containing base64 character data 703 * @return A BigInteger 704 * @since 1.4 705 */ 706 public static BigInteger decodeInteger(byte[] pArray) { 707 return new BigInteger(1, decodeBase64(pArray)); 708 } 709 710 /** 711 * Encodes to a byte64-encoded integer according to crypto standards such as W3C's XML-Signature 712 * 713 * @param bigInt 714 * a BigInteger 715 * @return A byte array containing base64 character data 716 * @throws NullPointerException 717 * if null is passed in 718 * @since 1.4 719 */ 720 public static byte[] encodeInteger(BigInteger bigInt) { 721 if (bigInt == null) { 722 throw new NullPointerException("encodeInteger called with null parameter"); 723 } 724 return encodeBase64(toIntegerBytes(bigInt), false); 725 } 726 727 /** 728 * Returns a byte-array representation of a <code>BigInteger</code> without sign bit. 729 * 730 * @param bigInt 731 * <code>BigInteger</code> to be converted 732 * @return a byte array representation of the BigInteger parameter 733 */ 734 static byte[] toIntegerBytes(BigInteger bigInt) { 735 int bitlen = bigInt.bitLength(); 736 // round bitlen 737 bitlen = ((bitlen + 7) >> 3) << 3; 738 byte[] bigBytes = bigInt.toByteArray(); 739 740 if (((bigInt.bitLength() % 8) != 0) && (((bigInt.bitLength() / 8) + 1) == (bitlen / 8))) { 741 return bigBytes; 742 } 743 // set up params for copying everything but sign bit 744 int startSrc = 0; 745 int len = bigBytes.length; 746 747 // if bigInt is exactly byte-aligned, just skip signbit in copy 748 if ((bigInt.bitLength() % 8) == 0) { 749 startSrc = 1; 750 len--; 751 } 752 int startDst = bitlen / 8 - len; // to pad w/ nulls as per spec 753 byte[] resizedBytes = new byte[bitlen / 8]; 754 System.arraycopy(bigBytes, startSrc, resizedBytes, startDst, len); 755 return resizedBytes; 756 } 757 758 /** 759 * Returns whether or not the <code>octet</code> is in the Base32 alphabet. 760 * 761 * @param octet 762 * The value to test 763 * @return {@code true} if the value is defined in the the Base32 alphabet {@code false} otherwise. 764 */ 765 @Override 766 protected boolean isInAlphabet(byte octet) { 767 return octet >= 0 && octet < decodeTable.length && decodeTable[octet] != -1; 768 } 769 770 }