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 encode/decode 040 * character encodings which are compatible with the lower 127 ASCII chart (ISO-8859-1, Windows-1252, UTF-8, etc). 041 * </p> 042 * <p> 043 * This class is not thread-safe. Each thread should use its own instance. 044 * </p> 045 * 046 * @see <a href="http://www.ietf.org/rfc/rfc2045.txt">RFC 2045</a> 047 * @author Apache Software Foundation 048 * @since 1.0 049 * @version $Revision: 1080712 $ 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 in 103 * 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 * Place holder for the bytes we're dealing with for our based logic. 161 * Bitwise operations store and extract the encoding or decoding from this variable. 162 */ 163 private int bitWorkArea; 164 165 /** 166 * Creates a Base64 codec used for decoding (all modes) and encoding in URL-unsafe mode. 167 * <p> 168 * When encoding the line length is 0 (no chunking), and the encoding table is STANDARD_ENCODE_TABLE. 169 * </p> 170 * 171 * <p> 172 * When decoding all variants are supported. 173 * </p> 174 */ 175 public Base64() { 176 this(0); 177 } 178 179 /** 180 * Creates a Base64 codec used for decoding (all modes) and encoding in the given URL-safe mode. 181 * <p> 182 * When encoding the line length is 76, the line separator is CRLF, and the encoding table is STANDARD_ENCODE_TABLE. 183 * </p> 184 * 185 * <p> 186 * When decoding all variants are supported. 187 * </p> 188 * 189 * @param urlSafe 190 * if <code>true</code>, URL-safe encoding is used. In most cases this should be set to 191 * <code>false</code>. 192 * @since 1.4 193 */ 194 public Base64(boolean urlSafe) { 195 this(MIME_CHUNK_SIZE, CHUNK_SEPARATOR, urlSafe); 196 } 197 198 /** 199 * Creates a Base64 codec used for decoding (all modes) and encoding in URL-unsafe mode. 200 * <p> 201 * When encoding the line length is given in the constructor, the line separator is CRLF, and the encoding table is 202 * STANDARD_ENCODE_TABLE. 203 * </p> 204 * <p> 205 * Line lengths that aren't multiples of 4 will still essentially end up being multiples of 4 in the encoded data. 206 * </p> 207 * <p> 208 * When decoding all variants are supported. 209 * </p> 210 * 211 * @param lineLength 212 * Each line of encoded data will be at most of the given length (rounded down to nearest multiple of 4). 213 * If lineLength <= 0, then the output will not be divided into lines (chunks). Ignored when decoding. 214 * @since 1.4 215 */ 216 public Base64(int lineLength) { 217 this(lineLength, CHUNK_SEPARATOR); 218 } 219 220 /** 221 * Creates a Base64 codec used for decoding (all modes) and encoding in URL-unsafe mode. 222 * <p> 223 * When encoding the line length and line separator are given in the constructor, and the encoding table is 224 * STANDARD_ENCODE_TABLE. 225 * </p> 226 * <p> 227 * Line lengths that aren't multiples of 4 will still essentially end up being multiples of 4 in the encoded data. 228 * </p> 229 * <p> 230 * When decoding all variants are supported. 231 * </p> 232 * 233 * @param lineLength 234 * Each line of encoded data will be at most of the given length (rounded down to nearest multiple of 4). 235 * If lineLength <= 0, then the output will not be divided into lines (chunks). Ignored when decoding. 236 * @param lineSeparator 237 * Each line of encoded data will end with this sequence of bytes. 238 * @throws IllegalArgumentException 239 * Thrown when the provided lineSeparator included some base64 characters. 240 * @since 1.4 241 */ 242 public Base64(int lineLength, byte[] lineSeparator) { 243 this(lineLength, lineSeparator, false); 244 } 245 246 /** 247 * Creates a Base64 codec used for decoding (all modes) and encoding in URL-unsafe mode. 248 * <p> 249 * When encoding the line length and line separator are given in the constructor, and the encoding table is 250 * STANDARD_ENCODE_TABLE. 251 * </p> 252 * <p> 253 * Line lengths that aren't multiples of 4 will still essentially end up being multiples of 4 in the encoded data. 254 * </p> 255 * <p> 256 * When decoding all variants are supported. 257 * </p> 258 * 259 * @param lineLength 260 * Each line of encoded data will be at most of the given length (rounded down to nearest multiple of 4). 261 * If lineLength <= 0, then the output will not be divided into lines (chunks). Ignored when decoding. 262 * @param lineSeparator 263 * Each line of encoded data will end with this sequence of bytes. 264 * @param urlSafe 265 * Instead of emitting '+' and '/' we emit '-' and '_' respectively. urlSafe is only applied to encode 266 * operations. Decoding seamlessly handles both modes. 267 * @throws IllegalArgumentException 268 * The provided lineSeparator included some base64 characters. That's not going to work! 269 * @since 1.4 270 */ 271 public Base64(int lineLength, byte[] lineSeparator, boolean urlSafe) { 272 super(BYTES_PER_UNENCODED_BLOCK, BYTES_PER_ENCODED_BLOCK, 273 lineLength, 274 lineSeparator == null ? 0 : lineSeparator.length); 275 // TODO could be simplified if there is no requirement to reject invalid line sep when length <=0 276 // @see test case Base64Test.testConstructors() 277 if (lineSeparator != null) { 278 if (containsAlphabetOrPad(lineSeparator)) { 279 String sep = StringUtils.newStringUtf8(lineSeparator); 280 throw new IllegalArgumentException("lineSeparator must not contain base64 characters: [" + sep + "]"); 281 } 282 if (lineLength > 0){ // null line-sep forces no chunking rather than throwing IAE 283 this.encodeSize = BYTES_PER_ENCODED_BLOCK + lineSeparator.length; 284 this.lineSeparator = new byte[lineSeparator.length]; 285 System.arraycopy(lineSeparator, 0, this.lineSeparator, 0, lineSeparator.length); 286 } else { 287 this.encodeSize = BYTES_PER_ENCODED_BLOCK; 288 this.lineSeparator = null; 289 } 290 } else { 291 this.encodeSize = BYTES_PER_ENCODED_BLOCK; 292 this.lineSeparator = null; 293 } 294 this.decodeSize = this.encodeSize - 1; 295 this.encodeTable = urlSafe ? URL_SAFE_ENCODE_TABLE : STANDARD_ENCODE_TABLE; 296 } 297 298 /** 299 * Returns our current encode mode. True if we're URL-SAFE, false otherwise. 300 * 301 * @return true if we're in URL-SAFE mode, false otherwise. 302 * @since 1.4 303 */ 304 public boolean isUrlSafe() { 305 return this.encodeTable == URL_SAFE_ENCODE_TABLE; 306 } 307 308 /** 309 * <p> 310 * Encodes all of the provided data, starting at inPos, for inAvail bytes. Must be called at least twice: once with 311 * the data to encode, and once with inAvail set to "-1" to alert encoder that EOF has been reached, so flush last 312 * remaining bytes (if not multiple of 3). 313 * </p> 314 * <p> 315 * Thanks to "commons" project in ws.apache.org for the bitwise operations, and general approach. 316 * http://svn.apache.org/repos/asf/webservices/commons/trunk/modules/util/ 317 * </p> 318 * 319 * @param in 320 * byte[] array of binary data to base64 encode. 321 * @param inPos 322 * Position to start reading data from. 323 * @param inAvail 324 * Amount of bytes available from input for encoding. 325 */ 326 void encode(byte[] in, int inPos, int inAvail) { 327 if (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 eof = true; 334 if (0 == modulus && lineLength == 0) { 335 return; // no leftovers to process and not using chunking 336 } 337 ensureBufferSize(encodeSize); 338 int savedPos = pos; 339 switch (modulus) { // 0-2 340 case 1 : // 8 bits = 6 + 2 341 buffer[pos++] = encodeTable[(bitWorkArea >> 2) & MASK_6BITS]; // top 6 bits 342 buffer[pos++] = encodeTable[(bitWorkArea << 4) & MASK_6BITS]; // remaining 2 343 // URL-SAFE skips the padding to further reduce size. 344 if (encodeTable == STANDARD_ENCODE_TABLE) { 345 buffer[pos++] = PAD; 346 buffer[pos++] = PAD; 347 } 348 break; 349 350 case 2 : // 16 bits = 6 + 6 + 4 351 buffer[pos++] = encodeTable[(bitWorkArea >> 10) & MASK_6BITS]; 352 buffer[pos++] = encodeTable[(bitWorkArea >> 4) & MASK_6BITS]; 353 buffer[pos++] = encodeTable[(bitWorkArea << 2) & MASK_6BITS]; 354 // URL-SAFE skips the padding to further reduce size. 355 if (encodeTable == STANDARD_ENCODE_TABLE) { 356 buffer[pos++] = PAD; 357 } 358 break; 359 } 360 currentLinePos += pos - savedPos; // keep track of current line position 361 // if currentPos == 0 we are at the start of a line, so don't add CRLF 362 if (lineLength > 0 && currentLinePos > 0) { 363 System.arraycopy(lineSeparator, 0, buffer, pos, lineSeparator.length); 364 pos += lineSeparator.length; 365 } 366 } else { 367 for (int i = 0; i < inAvail; i++) { 368 ensureBufferSize(encodeSize); 369 modulus = (modulus+1) % BYTES_PER_UNENCODED_BLOCK; 370 int b = in[inPos++]; 371 if (b < 0) { 372 b += 256; 373 } 374 bitWorkArea = (bitWorkArea << 8) + b; // BITS_PER_BYTE 375 if (0 == modulus) { // 3 bytes = 24 bits = 4 * 6 bits to extract 376 buffer[pos++] = encodeTable[(bitWorkArea >> 18) & MASK_6BITS]; 377 buffer[pos++] = encodeTable[(bitWorkArea >> 12) & MASK_6BITS]; 378 buffer[pos++] = encodeTable[(bitWorkArea >> 6) & MASK_6BITS]; 379 buffer[pos++] = encodeTable[bitWorkArea & MASK_6BITS]; 380 currentLinePos += BYTES_PER_ENCODED_BLOCK; 381 if (lineLength > 0 && lineLength <= currentLinePos) { 382 System.arraycopy(lineSeparator, 0, buffer, pos, lineSeparator.length); 383 pos += lineSeparator.length; 384 currentLinePos = 0; 385 } 386 } 387 } 388 } 389 } 390 391 /** 392 * <p> 393 * Decodes all of the provided data, starting at inPos, for inAvail bytes. Should be called at least twice: once 394 * with the data to decode, and once with inAvail set to "-1" to alert decoder that EOF has been reached. The "-1" 395 * call is not necessary when decoding, but it doesn't hurt, either. 396 * </p> 397 * <p> 398 * Ignores all non-base64 characters. This is how chunked (e.g. 76 character) data is handled, since CR and LF are 399 * silently ignored, but has implications for other bytes, too. This method subscribes to the garbage-in, 400 * garbage-out philosophy: it will not check the provided data for validity. 401 * </p> 402 * <p> 403 * Thanks to "commons" project in ws.apache.org for the bitwise operations, and general approach. 404 * http://svn.apache.org/repos/asf/webservices/commons/trunk/modules/util/ 405 * </p> 406 * 407 * @param in 408 * byte[] array of ascii data to base64 decode. 409 * @param inPos 410 * Position to start reading data from. 411 * @param inAvail 412 * Amount of bytes available from input for encoding. 413 */ 414 void decode(byte[] in, int inPos, int inAvail) { 415 if (eof) { 416 return; 417 } 418 if (inAvail < 0) { 419 eof = true; 420 } 421 for (int i = 0; i < inAvail; i++) { 422 ensureBufferSize(decodeSize); 423 byte b = in[inPos++]; 424 if (b == PAD) { 425 // We're done. 426 eof = true; 427 break; 428 } else { 429 if (b >= 0 && b < DECODE_TABLE.length) { 430 int result = DECODE_TABLE[b]; 431 if (result >= 0) { 432 modulus = (modulus+1) % BYTES_PER_ENCODED_BLOCK; 433 bitWorkArea = (bitWorkArea << BITS_PER_ENCODED_BYTE) + result; 434 if (modulus == 0) { 435 buffer[pos++] = (byte) ((bitWorkArea >> 16) & MASK_8BITS); 436 buffer[pos++] = (byte) ((bitWorkArea >> 8) & MASK_8BITS); 437 buffer[pos++] = (byte) (bitWorkArea & MASK_8BITS); 438 } 439 } 440 } 441 } 442 } 443 444 // Two forms of EOF as far as base64 decoder is concerned: actual 445 // EOF (-1) and first time '=' character is encountered in stream. 446 // This approach makes the '=' padding characters completely optional. 447 if (eof && modulus != 0) { 448 ensureBufferSize(decodeSize); 449 450 // We have some spare bits remaining 451 // Output all whole multiples of 8 bits and ignore the rest 452 switch (modulus) { 453 // case 1: // 6 bits - ignore entirely 454 // break; 455 case 2 : // 12 bits = 8 + 4 456 bitWorkArea = bitWorkArea >> 4; // dump the extra 4 bits 457 buffer[pos++] = (byte) ((bitWorkArea) & MASK_8BITS); 458 break; 459 case 3 : // 18 bits = 8 + 8 + 2 460 bitWorkArea = bitWorkArea >> 2; // dump 2 bits 461 buffer[pos++] = (byte) ((bitWorkArea >> 8) & MASK_8BITS); 462 buffer[pos++] = (byte) ((bitWorkArea) & MASK_8BITS); 463 break; 464 } 465 } 466 } 467 468 /** 469 * Returns whether or not the <code>octet</code> is in the base 64 alphabet. 470 * 471 * @param octet 472 * The value to test 473 * @return <code>true</code> if the value is defined in the the base 64 alphabet, <code>false</code> otherwise. 474 * @since 1.4 475 */ 476 public static boolean isBase64(byte octet) { 477 return octet == PAD_DEFAULT || (octet >= 0 && octet < DECODE_TABLE.length && DECODE_TABLE[octet] != -1); 478 } 479 480 /** 481 * Tests a given String to see if it contains only valid characters within the Base64 alphabet. Currently the 482 * method treats whitespace as valid. 483 * 484 * @param base64 485 * String to test 486 * @return <code>true</code> if all characters in the String are valid characters in the Base64 alphabet or if 487 * the String is empty; <code>false</code>, otherwise 488 * @since 1.5 489 */ 490 public static boolean isBase64(String base64) { 491 return isBase64(StringUtils.getBytesUtf8(base64)); 492 } 493 494 /** 495 * Tests a given byte array to see if it contains only valid characters within the Base64 alphabet. Currently the 496 * method treats whitespace as valid. 497 * 498 * @param arrayOctet 499 * byte array to test 500 * @return <code>true</code> if all bytes are valid characters in the Base64 alphabet or if the byte array is empty; 501 * <code>false</code>, otherwise 502 * @deprecated 1.5 Use {@link #isBase64(byte[])}, will be removed in 2.0. 503 */ 504 public static boolean isArrayByteBase64(byte[] arrayOctet) { 505 return isBase64(arrayOctet); 506 } 507 508 /** 509 * Tests a given byte array to see if it contains only valid characters within the Base64 alphabet. Currently the 510 * method treats whitespace as valid. 511 * 512 * @param arrayOctet 513 * byte array to test 514 * @return <code>true</code> if all bytes are valid characters in the Base64 alphabet or if the byte array is empty; 515 * <code>false</code>, otherwise 516 * @since 1.5 517 */ 518 public static boolean isBase64(byte[] arrayOctet) { 519 for (int i = 0; i < arrayOctet.length; i++) { 520 if (!isBase64(arrayOctet[i]) && !isWhiteSpace(arrayOctet[i])) { 521 return false; 522 } 523 } 524 return true; 525 } 526 527 /** 528 * Encodes binary data using the base64 algorithm but does not chunk the output. 529 * 530 * @param binaryData 531 * binary data to encode 532 * @return byte[] containing Base64 characters in their UTF-8 representation. 533 */ 534 public static byte[] encodeBase64(byte[] binaryData) { 535 return encodeBase64(binaryData, false); 536 } 537 538 /** 539 * Encodes binary data using the base64 algorithm but does not chunk the output. 540 * 541 * NOTE: We changed the behaviour of this method from multi-line chunking (commons-codec-1.4) to 542 * single-line non-chunking (commons-codec-1.5). 543 * 544 * @param binaryData 545 * binary data to encode 546 * @return String containing Base64 characters. 547 * @since 1.4 (NOTE: 1.4 chunked the output, whereas 1.5 does not). 548 */ 549 public static String encodeBase64String(byte[] binaryData) { 550 return StringUtils.newStringUtf8(encodeBase64(binaryData, false)); 551 } 552 553 /** 554 * Encodes binary data using a URL-safe variation of the base64 algorithm but does not chunk the output. The 555 * url-safe variation emits - and _ instead of + and / characters. 556 * 557 * @param binaryData 558 * binary data to encode 559 * @return byte[] containing Base64 characters in their UTF-8 representation. 560 * @since 1.4 561 */ 562 public static byte[] encodeBase64URLSafe(byte[] binaryData) { 563 return encodeBase64(binaryData, false, true); 564 } 565 566 /** 567 * Encodes binary data using a URL-safe variation of the base64 algorithm but does not chunk the output. The 568 * url-safe variation emits - and _ instead of + and / characters. 569 * 570 * @param binaryData 571 * binary data to encode 572 * @return String containing Base64 characters 573 * @since 1.4 574 */ 575 public static String encodeBase64URLSafeString(byte[] binaryData) { 576 return StringUtils.newStringUtf8(encodeBase64(binaryData, false, true)); 577 } 578 579 /** 580 * Encodes binary data using the base64 algorithm and chunks the encoded output into 76 character blocks 581 * 582 * @param binaryData 583 * binary data to encode 584 * @return Base64 characters chunked in 76 character blocks 585 */ 586 public static byte[] encodeBase64Chunked(byte[] binaryData) { 587 return encodeBase64(binaryData, true); 588 } 589 590 /** 591 * Encodes binary data using the base64 algorithm, optionally chunking the output into 76 character blocks. 592 * 593 * @param binaryData 594 * Array containing binary data to encode. 595 * @param isChunked 596 * if <code>true</code> this encoder will chunk the base64 output into 76 character blocks 597 * @return Base64-encoded data. 598 * @throws IllegalArgumentException 599 * Thrown when the input array needs an output array bigger than {@link Integer#MAX_VALUE} 600 */ 601 public static byte[] encodeBase64(byte[] binaryData, boolean isChunked) { 602 return encodeBase64(binaryData, isChunked, false); 603 } 604 605 /** 606 * Encodes binary data using the base64 algorithm, optionally chunking the output into 76 character blocks. 607 * 608 * @param binaryData 609 * Array containing binary data to encode. 610 * @param isChunked 611 * if <code>true</code> this encoder will chunk the base64 output into 76 character blocks 612 * @param urlSafe 613 * if <code>true</code> this encoder will emit - and _ instead of the usual + and / characters. 614 * @return Base64-encoded data. 615 * @throws IllegalArgumentException 616 * Thrown when the input array needs an output array bigger than {@link Integer#MAX_VALUE} 617 * @since 1.4 618 */ 619 public static byte[] encodeBase64(byte[] binaryData, boolean isChunked, boolean urlSafe) { 620 return encodeBase64(binaryData, isChunked, urlSafe, Integer.MAX_VALUE); 621 } 622 623 /** 624 * Encodes binary data using the base64 algorithm, optionally chunking the output into 76 character blocks. 625 * 626 * @param binaryData 627 * Array containing binary data to encode. 628 * @param isChunked 629 * if <code>true</code> this encoder will chunk the base64 output into 76 character blocks 630 * @param urlSafe 631 * if <code>true</code> this encoder will emit - and _ instead of the usual + and / characters. 632 * @param maxResultSize 633 * The maximum result size to accept. 634 * @return Base64-encoded data. 635 * @throws IllegalArgumentException 636 * Thrown when the input array needs an output array bigger than maxResultSize 637 * @since 1.4 638 */ 639 public static byte[] encodeBase64(byte[] binaryData, boolean isChunked, boolean urlSafe, int maxResultSize) { 640 if (binaryData == null || binaryData.length == 0) { 641 return binaryData; 642 } 643 644 // Create this so can use the super-class method 645 // Also ensures that the same roundings are performed by the ctor and the code 646 Base64 b64 = isChunked ? new Base64(urlSafe) : new Base64(0, CHUNK_SEPARATOR, urlSafe); 647 long len = b64.getEncodedLength(binaryData); 648 if (len > maxResultSize) { 649 throw new IllegalArgumentException("Input array too big, the output array would be bigger (" + 650 len + 651 ") than the specified maximum size of " + 652 maxResultSize); 653 } 654 655 return b64.encode(binaryData); 656 } 657 658 /** 659 * Decodes a Base64 String into octets 660 * 661 * @param base64String 662 * String containing Base64 data 663 * @return Array containing decoded data. 664 * @since 1.4 665 */ 666 public static byte[] decodeBase64(String base64String) { 667 return new Base64().decode(base64String); 668 } 669 670 /** 671 * Decodes Base64 data into octets 672 * 673 * @param base64Data 674 * Byte array containing Base64 data 675 * @return Array containing decoded data. 676 */ 677 public static byte[] decodeBase64(byte[] base64Data) { 678 return new Base64().decode(base64Data); 679 } 680 681 // Implementation of the Encoder Interface 682 683 // Implementation of integer encoding used for crypto 684 /** 685 * Decodes a byte64-encoded integer according to crypto standards such as W3C's XML-Signature 686 * 687 * @param pArray 688 * a byte array containing base64 character data 689 * @return A BigInteger 690 * @since 1.4 691 */ 692 public static BigInteger decodeInteger(byte[] pArray) { 693 return new BigInteger(1, decodeBase64(pArray)); 694 } 695 696 /** 697 * Encodes to a byte64-encoded integer according to crypto standards such as W3C's XML-Signature 698 * 699 * @param bigInt 700 * a BigInteger 701 * @return A byte array containing base64 character data 702 * @throws NullPointerException 703 * if null is passed in 704 * @since 1.4 705 */ 706 public static byte[] encodeInteger(BigInteger bigInt) { 707 if (bigInt == null) { 708 throw new NullPointerException("encodeInteger called with null parameter"); 709 } 710 return encodeBase64(toIntegerBytes(bigInt), false); 711 } 712 713 /** 714 * Returns a byte-array representation of a <code>BigInteger</code> without sign bit. 715 * 716 * @param bigInt 717 * <code>BigInteger</code> to be converted 718 * @return a byte array representation of the BigInteger parameter 719 */ 720 static byte[] toIntegerBytes(BigInteger bigInt) { 721 int bitlen = bigInt.bitLength(); 722 // round bitlen 723 bitlen = ((bitlen + 7) >> 3) << 3; 724 byte[] bigBytes = bigInt.toByteArray(); 725 726 if (((bigInt.bitLength() % 8) != 0) && (((bigInt.bitLength() / 8) + 1) == (bitlen / 8))) { 727 return bigBytes; 728 } 729 // set up params for copying everything but sign bit 730 int startSrc = 0; 731 int len = bigBytes.length; 732 733 // if bigInt is exactly byte-aligned, just skip signbit in copy 734 if ((bigInt.bitLength() % 8) == 0) { 735 startSrc = 1; 736 len--; 737 } 738 int startDst = bitlen / 8 - len; // to pad w/ nulls as per spec 739 byte[] resizedBytes = new byte[bitlen / 8]; 740 System.arraycopy(bigBytes, startSrc, resizedBytes, startDst, len); 741 return resizedBytes; 742 } 743 744 /** 745 * Returns whether or not the <code>octet</code> is in the Base32 alphabet. 746 * 747 * @param octet 748 * The value to test 749 * @return <code>true</code> if the value is defined in the the Base32 alphabet <code>false</code> otherwise. 750 */ 751 protected boolean isInAlphabet(byte octet) { 752 return octet >= 0 && octet < decodeTable.length && decodeTable[octet] != -1; 753 } 754 755 }