1 /*
2 * reserved comment block
3 * DO NOT REMOVE OR ALTER!
4 */
5 /*
6 * Copyright 1999-2004 The Apache Software Foundation.
7 *
8 * Licensed under the Apache License, Version 2.0 (the "License");
9 * you may not use this file except in compliance with the License.
10 * You may obtain a copy of the License at
11 *
12 * http://www.apache.org/licenses/LICENSE-2.0
13 *
14 * Unless required by applicable law or agreed to in writing, software
15 * distributed under the License is distributed on an "AS IS" BASIS,
16 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
17 * See the License for the specific language governing permissions and
18 * limitations under the License.
19 *
20 */
21 package com.sun.org.apache.xml.internal.security.utils;
22
23 import java.io.BufferedReader;
24 import java.io.IOException;
25 import java.io.InputStream;
26 import java.io.OutputStream;
27 import java.math.BigInteger;
28
29 import com.sun.org.apache.xml.internal.security.exceptions.Base64DecodingException;
30 import org.w3c.dom.Document;
31 import org.w3c.dom.Element;
32 import org.w3c.dom.Node;
33 import org.w3c.dom.Text;
34
35
36 /**
37 * Implementation of MIME's Base64 encoding and decoding conversions.
38 * Optimized code. (raw version taken from oreilly.jonathan.util,
39 * and currently com.sun.org.apache.xerces.internal.ds.util.Base64)
40 *
41 * @author Raul Benito(Of the xerces copy, and little adaptations).
42 * @author Anli Shundi
43 * @author Christian Geuer-Pollmann
44 * @see <A HREF="http://www.ietf.org/rfc/rfc2045.txt">RFC 2045</A>
45 * @see com.sun.org.apache.xml.internal.security.transforms.implementations.TransformBase64Decode
46 */
47 public class Base64 {
48
49
50 /** Field BASE64DEFAULTLENGTH */
51 public static final int BASE64DEFAULTLENGTH = 76;
52
53 private Base64() {
54 // we don't allow instantiation
55 }
56
57 /**
58 * Returns a byte-array representation of a <code>{@link BigInteger}<code>.
59 * No sign-bit is outputed.
60 *
61 * <b>N.B.:</B> <code>{@link BigInteger}<code>'s toByteArray
62 * retunrs eventually longer arrays because of the leading sign-bit.
63 *
64 * @param big <code>BigInteger<code> to be converted
65 * @param bitlen <code>int<code> the desired length in bits of the representation
66 * @return a byte array with <code>bitlen</code> bits of <code>big</code>
67 */
68 static final byte[] getBytes(BigInteger big, int bitlen) {
69
70 //round bitlen
71 bitlen = ((bitlen + 7) >> 3) << 3;
72
73 if (bitlen < big.bitLength()) {
74 throw new IllegalArgumentException(I18n
75 .translate("utils.Base64.IllegalBitlength"));
76 }
77
78 byte[] bigBytes = big.toByteArray();
79
80 if (((big.bitLength() % 8) != 0)
81 && (((big.bitLength() / 8) + 1) == (bitlen / 8))) {
82 return bigBytes;
83 }
84
85 // some copying needed
86 int startSrc = 0; // no need to skip anything
87 int bigLen = bigBytes.length; //valid length of the string
88
89 if ((big.bitLength() % 8) == 0) { // correct values
90 startSrc = 1; // skip sign bit
91
92 bigLen--; // valid length of the string
93 }
94
95 int startDst = bitlen / 8 - bigLen; //pad with leading nulls
96 byte[] resizedBytes = new byte[bitlen / 8];
97
98 System.arraycopy(bigBytes, startSrc, resizedBytes, startDst, bigLen);
99
100 return resizedBytes;
101
102 }
103
104 /**
105 * Encode in Base64 the given <code>{@link BigInteger}<code>.
106 *
107 * @param big
108 * @return String with Base64 encoding
109 */
110 public static final String encode(BigInteger big) {
111 return encode(getBytes(big, big.bitLength()));
112 }
113
114 /**
115 * Returns a byte-array representation of a <code>{@link BigInteger}<code>.
116 * No sign-bit is outputed.
117 *
118 * <b>N.B.:</B> <code>{@link BigInteger}<code>'s toByteArray
119 * retunrs eventually longer arrays because of the leading sign-bit.
120 *
121 * @param big <code>BigInteger<code> to be converted
122 * @param bitlen <code>int<code> the desired length in bits of the representation
123 * @return a byte array with <code>bitlen</code> bits of <code>big</code>
124 */
125 public static final byte[] encode(BigInteger big, int bitlen) {
126
127 //round bitlen
128 bitlen = ((bitlen + 7) >> 3) << 3;
129
130 if (bitlen < big.bitLength()) {
131 throw new IllegalArgumentException(I18n
132 .translate("utils.Base64.IllegalBitlength"));
133 }
134
135 byte[] bigBytes = big.toByteArray();
136
137 if (((big.bitLength() % 8) != 0)
138 && (((big.bitLength() / 8) + 1) == (bitlen / 8))) {
139 return bigBytes;
140 }
141
142 // some copying needed
143 int startSrc = 0; // no need to skip anything
144 int bigLen = bigBytes.length; //valid length of the string
145
146 if ((big.bitLength() % 8) == 0) { // correct values
147 startSrc = 1; // skip sign bit
148
149 bigLen--; // valid length of the string
150 }
151
152 int startDst = bitlen / 8 - bigLen; //pad with leading nulls
153 byte[] resizedBytes = new byte[bitlen / 8];
154
155 System.arraycopy(bigBytes, startSrc, resizedBytes, startDst, bigLen);
156
157 return resizedBytes;
158
159 }
160
161 /**
162 * Method decodeBigIntegerFromElement
163 *
164 * @param element
165 * @return the biginter obtained from the node
166 * @throws Base64DecodingException
167 */
168 public static final BigInteger decodeBigIntegerFromElement(Element element) throws Base64DecodingException
169 {
170 return new BigInteger(1, Base64.decode(element));
171 }
172
173 /**
174 * Method decodeBigIntegerFromText
175 *
176 * @param text
177 * @return the biginter obtained from the text node
178 * @throws Base64DecodingException
179 */
180 public static final BigInteger decodeBigIntegerFromText(Text text) throws Base64DecodingException
181 {
182 return new BigInteger(1, Base64.decode(text.getData()));
183 }
184
185 /**
186 * This method takes an (empty) Element and a BigInteger and adds the
187 * base64 encoded BigInteger to the Element.
188 *
189 * @param element
190 * @param biginteger
191 */
192 public static final void fillElementWithBigInteger(Element element,
193 BigInteger biginteger) {
194
195 String encodedInt = encode(biginteger);
196
197 if (encodedInt.length() > 76) {
198 encodedInt = "\n" + encodedInt + "\n";
199 }
200
201 Document doc = element.getOwnerDocument();
202 Text text = doc.createTextNode(encodedInt);
203
204 element.appendChild(text);
205 }
206
207 /**
208 * Method decode
209 *
210 * Takes the <CODE>Text</CODE> children of the Element and interprets
211 * them as input for the <CODE>Base64.decode()</CODE> function.
212 *
213 * @param element
214 * @return the byte obtained of the decoding the element
215 * $todo$ not tested yet
216 * @throws Base64DecodingException
217 */
218 public static final byte[] decode(Element element) throws Base64DecodingException {
219
220 Node sibling = element.getFirstChild();
221 StringBuffer sb = new StringBuffer();
222
223 while (sibling!=null) {
224 if (sibling.getNodeType() == Node.TEXT_NODE) {
225 Text t = (Text) sibling;
226
227 sb.append(t.getData());
228 }
229 sibling=sibling.getNextSibling();
230 }
231
232 return decode(sb.toString());
233 }
234
235 /**
236 * Method encodeToElement
237 *
238 * @param doc
239 * @param localName
240 * @param bytes
241 * @return an Element with the base64 encoded in the text.
242 *
243 */
244 public static final Element encodeToElement(Document doc, String localName,
245 byte[] bytes) {
246
247 Element el = XMLUtils.createElementInSignatureSpace(doc, localName);
248 Text text = doc.createTextNode(encode(bytes));
249
250 el.appendChild(text);
251
252 return el;
253 }
254
255 /**
256 * Method decode
257 *
258 *
259 * @param base64
260 * @return the UTF bytes of the base64
261 * @throws Base64DecodingException
262 *
263 */
264 public final static byte[] decode(byte[] base64) throws Base64DecodingException {
265 return decodeInternal(base64, -1);
266 }
267
268
269
270 /**
271 * Encode a byte array and fold lines at the standard 76th character unless
272 * ignore line breaks property is set.
273 *
274 * @param binaryData <code>byte[]<code> to be base64 encoded
275 * @return the <code>String<code> with encoded data
276 */
277 public static final String encode(byte[] binaryData) {
278 return XMLUtils.ignoreLineBreaks()
279 ? encode(binaryData, Integer.MAX_VALUE)
280 : encode(binaryData, BASE64DEFAULTLENGTH);
281 }
282
283 /**
284 * Base64 decode the lines from the reader and return an InputStream
285 * with the bytes.
286 *
287 *
288 * @param reader
289 * @return InputStream with the decoded bytes
290 * @exception IOException passes what the reader throws
291 * @throws IOException
292 * @throws Base64DecodingException
293 */
294 public final static byte[] decode(BufferedReader reader)
295 throws IOException, Base64DecodingException {
296
297 UnsyncByteArrayOutputStream baos = new UnsyncByteArrayOutputStream();
298 String line;
299
300 while (null != (line = reader.readLine())) {
301 byte[] bytes = decode(line);
302
303 baos.write(bytes);
304 }
305
306 return baos.toByteArray();
307 }
308
309 static private final int BASELENGTH = 255;
310 static private final int LOOKUPLENGTH = 64;
311 static private final int TWENTYFOURBITGROUP = 24;
312 static private final int EIGHTBIT = 8;
313 static private final int SIXTEENBIT = 16;
314 static private final int FOURBYTE = 4;
315 static private final int SIGN = -128;
316 static private final char PAD = '=';
317 static final private byte [] base64Alphabet = new byte[BASELENGTH];
318 static final private char [] lookUpBase64Alphabet = new char[LOOKUPLENGTH];
319
320 static {
321
322 for (int i = 0; i<BASELENGTH; i++) {
323 base64Alphabet[i] = -1;
324 }
325 for (int i = 'Z'; i >= 'A'; i--) {
326 base64Alphabet[i] = (byte) (i-'A');
327 }
328 for (int i = 'z'; i>= 'a'; i--) {
329 base64Alphabet[i] = (byte) ( i-'a' + 26);
330 }
331
332 for (int i = '9'; i >= '0'; i--) {
333 base64Alphabet[i] = (byte) (i-'0' + 52);
334 }
335
336 base64Alphabet['+'] = 62;
337 base64Alphabet['/'] = 63;
338
339 for (int i = 0; i<=25; i++)
340 lookUpBase64Alphabet[i] = (char)('A'+i);
341
342 for (int i = 26, j = 0; i<=51; i++, j++)
343 lookUpBase64Alphabet[i] = (char)('a'+ j);
344
345 for (int i = 52, j = 0; i<=61; i++, j++)
346 lookUpBase64Alphabet[i] = (char)('0' + j);
347 lookUpBase64Alphabet[62] = '+';
348 lookUpBase64Alphabet[63] = '/';
349
350 }
351
352 protected static final boolean isWhiteSpace(byte octect) {
353 return (octect == 0x20 || octect == 0xd || octect == 0xa || octect == 0x9);
354 }
355
356 protected static final boolean isPad(byte octect) {
357 return (octect == PAD);
358 }
359
360
361 /**
362 * Encodes hex octects into Base64
363 *
364 * @param binaryData Array containing binaryData
365 * @return Encoded Base64 array
366 */
367 /**
368 * Encode a byte array in Base64 format and return an optionally
369 * wrapped line.
370 *
371 * @param binaryData <code>byte[]</code> data to be encoded
372 * @param length <code>int<code> length of wrapped lines; No wrapping if less than 4.
373 * @return a <code>String</code> with encoded data
374 */
375 public static final String encode(byte[] binaryData,int length) {
376
377 if (length<4) {
378 length=Integer.MAX_VALUE;
379 }
380
381 if (binaryData == null)
382 return null;
383
384 int lengthDataBits = binaryData.length*EIGHTBIT;
385 if (lengthDataBits == 0) {
386 return "";
387 }
388
389 int fewerThan24bits = lengthDataBits%TWENTYFOURBITGROUP;
390 int numberTriplets = lengthDataBits/TWENTYFOURBITGROUP;
391 int numberQuartet = fewerThan24bits != 0 ? numberTriplets+1 : numberTriplets;
392 int quartesPerLine = length/4;
393 int numberLines = (numberQuartet-1)/quartesPerLine;
394 char encodedData[] = null;
395
396 encodedData = new char[numberQuartet*4+numberLines];
397
398 byte k=0, l=0, b1=0,b2=0,b3=0;
399
400 int encodedIndex = 0;
401 int dataIndex = 0;
402 int i = 0;
403
404
405 for (int line = 0; line < numberLines; line++) {
406 for (int quartet = 0; quartet < 19; quartet++) {
407 b1 = binaryData[dataIndex++];
408 b2 = binaryData[dataIndex++];
409 b3 = binaryData[dataIndex++];
410
411
412 l = (byte)(b2 & 0x0f);
413 k = (byte)(b1 & 0x03);
414
415 byte val1 = ((b1 & SIGN)==0)?(byte)(b1>>2):(byte)((b1)>>2^0xc0);
416
417 byte val2 = ((b2 & SIGN)==0)?(byte)(b2>>4):(byte)((b2)>>4^0xf0);
418 byte val3 = ((b3 & SIGN)==0)?(byte)(b3>>6):(byte)((b3)>>6^0xfc);
419
420
421 encodedData[encodedIndex++] = lookUpBase64Alphabet[ val1 ];
422 encodedData[encodedIndex++] = lookUpBase64Alphabet[ val2 | ( k<<4 )];
423 encodedData[encodedIndex++] = lookUpBase64Alphabet[ (l <<2 ) | val3 ];
424 encodedData[encodedIndex++] = lookUpBase64Alphabet[ b3 & 0x3f ];
425
426 i++;
427 }
428 encodedData[encodedIndex++] = 0xa;
429 }
430
431 for (; i<numberTriplets; i++) {
432 b1 = binaryData[dataIndex++];
433 b2 = binaryData[dataIndex++];
434 b3 = binaryData[dataIndex++];
435
436
437 l = (byte)(b2 & 0x0f);
438 k = (byte)(b1 & 0x03);
439
440 byte val1 = ((b1 & SIGN)==0)?(byte)(b1>>2):(byte)((b1)>>2^0xc0);
441
442 byte val2 = ((b2 & SIGN)==0)?(byte)(b2>>4):(byte)((b2)>>4^0xf0);
443 byte val3 = ((b3 & SIGN)==0)?(byte)(b3>>6):(byte)((b3)>>6^0xfc);
444
445
446 encodedData[encodedIndex++] = lookUpBase64Alphabet[ val1 ];
447 encodedData[encodedIndex++] = lookUpBase64Alphabet[ val2 | ( k<<4 )];
448 encodedData[encodedIndex++] = lookUpBase64Alphabet[ (l <<2 ) | val3 ];
449 encodedData[encodedIndex++] = lookUpBase64Alphabet[ b3 & 0x3f ];
450 }
451
452 // form integral number of 6-bit groups
453 if (fewerThan24bits == EIGHTBIT) {
454 b1 = binaryData[dataIndex];
455 k = (byte) ( b1 &0x03 );
456 byte val1 = ((b1 & SIGN)==0)?(byte)(b1>>2):(byte)((b1)>>2^0xc0);
457 encodedData[encodedIndex++] = lookUpBase64Alphabet[ val1 ];
458 encodedData[encodedIndex++] = lookUpBase64Alphabet[ k<<4 ];
459 encodedData[encodedIndex++] = PAD;
460 encodedData[encodedIndex++] = PAD;
461 } else if (fewerThan24bits == SIXTEENBIT) {
462 b1 = binaryData[dataIndex];
463 b2 = binaryData[dataIndex +1 ];
464 l = ( byte ) ( b2 &0x0f );
465 k = ( byte ) ( b1 &0x03 );
466
467 byte val1 = ((b1 & SIGN)==0)?(byte)(b1>>2):(byte)((b1)>>2^0xc0);
468 byte val2 = ((b2 & SIGN)==0)?(byte)(b2>>4):(byte)((b2)>>4^0xf0);
469
470 encodedData[encodedIndex++] = lookUpBase64Alphabet[ val1 ];
471 encodedData[encodedIndex++] = lookUpBase64Alphabet[ val2 | ( k<<4 )];
472 encodedData[encodedIndex++] = lookUpBase64Alphabet[ l<<2 ];
473 encodedData[encodedIndex++] = PAD;
474 }
475
476 //encodedData[encodedIndex] = 0xa;
477
478 return new String(encodedData);
479 }
480
481 /**
482 * Decodes Base64 data into octects
483 *
484 * @param encoded String containing base64 encoded data
485 * @return byte array containing the decoded data
486 * @throws Base64DecodingException if there is a problem decoding the data
487 */
488 public final static byte[] decode(String encoded) throws Base64DecodingException {
489
490 if (encoded == null)
491 return null;
492 byte []bytes=new byte[encoded.length()];
493 int len=getBytesInternal(encoded, bytes);
494 return decodeInternal(bytes, len);
495 }
496
497 protected static final int getBytesInternal(String s,byte[] result) {
498 int length=s.length();
499
500 int newSize=0;
501 for (int i = 0; i < length; i++) {
502 byte dataS=(byte)s.charAt(i);
503 if (!isWhiteSpace(dataS))
504 result[newSize++] = dataS;
505 }
506 return newSize;
507
508 }
509 protected final static byte[] decodeInternal(byte[] base64Data, int len) throws Base64DecodingException {
510 // remove white spaces
511 if (len==-1)
512 len = removeWhiteSpace(base64Data);
513
514 if (len%FOURBYTE != 0) {
515 throw new Base64DecodingException("decoding.divisible.four");
516 //should be divisible by four
517 }
518
519 int numberQuadruple = (len/FOURBYTE );
520
521 if (numberQuadruple == 0)
522 return new byte[0];
523
524 byte decodedData[] = null;
525 byte b1=0,b2=0,b3=0, b4=0;
526
527
528 int i = 0;
529 int encodedIndex = 0;
530 int dataIndex = 0;
531
532 //decodedData = new byte[ (numberQuadruple)*3];
533 dataIndex=(numberQuadruple-1)*4;
534 encodedIndex=(numberQuadruple-1)*3;
535 //first last bits.
536 b1 = base64Alphabet[base64Data[dataIndex++]];
537 b2 = base64Alphabet[base64Data[dataIndex++]];
538 if ((b1==-1) || (b2==-1)) {
539 throw new Base64DecodingException("decoding.general");//if found "no data" just return null
540 }
541
542
543 byte d3,d4;
544 b3 = base64Alphabet[d3=base64Data[dataIndex++]];
545 b4 = base64Alphabet[d4=base64Data[dataIndex++]];
546 if ((b3==-1 ) || (b4==-1) ) {
547 //Check if they are PAD characters
548 if (isPad( d3 ) && isPad( d4)) { //Two PAD e.g. 3c[Pad][Pad]
549 if ((b2 & 0xf) != 0)//last 4 bits should be zero
550 throw new Base64DecodingException("decoding.general");
551 decodedData = new byte[ encodedIndex + 1 ];
552 decodedData[encodedIndex] = (byte)( b1 <<2 | b2>>4 ) ;
553 } else if (!isPad( d3) && isPad(d4)) { //One PAD e.g. 3cQ[Pad]
554 if ((b3 & 0x3 ) != 0)//last 2 bits should be zero
555 throw new Base64DecodingException("decoding.general");
556 decodedData = new byte[ encodedIndex + 2 ];
557 decodedData[encodedIndex++] = (byte)( b1 <<2 | b2>>4 );
558 decodedData[encodedIndex] = (byte)(((b2 & 0xf)<<4 ) |( (b3>>2) & 0xf) );
559 } else {
560 throw new Base64DecodingException("decoding.general");//an error like "3c[Pad]r", "3cdX", "3cXd", "3cXX" where X is non data
561 }
562 } else {
563 //No PAD e.g 3cQl
564 decodedData = new byte[encodedIndex+3];
565 decodedData[encodedIndex++] = (byte)( b1 <<2 | b2>>4 ) ;
566 decodedData[encodedIndex++] = (byte)(((b2 & 0xf)<<4 ) |( (b3>>2) & 0xf) );
567 decodedData[encodedIndex++] = (byte)( b3<<6 | b4 );
568 }
569 encodedIndex=0;
570 dataIndex=0;
571 //the begin
572 for (i=numberQuadruple-1; i>0; i--) {
573 b1 = base64Alphabet[base64Data[dataIndex++]];
574 b2 = base64Alphabet[base64Data[dataIndex++]];
575 b3 = base64Alphabet[base64Data[dataIndex++]];
576 b4 = base64Alphabet[base64Data[dataIndex++]];
577
578 if ( (b1==-1) ||
579 (b2==-1) ||
580 (b3==-1) ||
581 (b4==-1) ) {
582 throw new Base64DecodingException("decoding.general");//if found "no data" just return null
583 }
584
585 decodedData[encodedIndex++] = (byte)( b1 <<2 | b2>>4 ) ;
586 decodedData[encodedIndex++] = (byte)(((b2 & 0xf)<<4 ) |( (b3>>2) & 0xf) );
587 decodedData[encodedIndex++] = (byte)( b3<<6 | b4 );
588 }
589 return decodedData;
590 }
591 /**
592 * Decodes Base64 data into outputstream
593 *
594 * @param base64Data String containing Base64 data
595 * @param os the outputstream
596 * @throws IOException
597 * @throws Base64DecodingException
598 */
599 public final static void decode(String base64Data,
600 OutputStream os) throws Base64DecodingException, IOException {
601 byte[] bytes=new byte[base64Data.length()];
602 int len=getBytesInternal(base64Data, bytes);
603 decode(bytes,os,len);
604 }
605 /**
606 * Decodes Base64 data into outputstream
607 *
608 * @param base64Data Byte array containing Base64 data
609 * @param os the outputstream
610 * @throws IOException
611 * @throws Base64DecodingException
612 */
613 public final static void decode(byte[] base64Data,
614 OutputStream os) throws Base64DecodingException, IOException {
615 decode(base64Data,os,-1);
616 }
617 protected final static void decode(byte[] base64Data,
618 OutputStream os,int len) throws Base64DecodingException, IOException {
619
620 // remove white spaces
621 if (len==-1)
622 len = removeWhiteSpace(base64Data);
623
624 if (len%FOURBYTE != 0) {
625 throw new Base64DecodingException("decoding.divisible.four");
626 //should be divisible by four
627 }
628
629 int numberQuadruple = (len/FOURBYTE );
630
631 if (numberQuadruple == 0)
632 return;
633
634 //byte decodedData[] = null;
635 byte b1=0,b2=0,b3=0, b4=0;
636
637 int i = 0;
638
639 int dataIndex = 0;
640
641 //the begin
642 for (i=numberQuadruple-1; i>0; i--) {
643 b1 = base64Alphabet[base64Data[dataIndex++]];
644 b2 = base64Alphabet[base64Data[dataIndex++]];
645 b3 = base64Alphabet[base64Data[dataIndex++]];
646 b4 = base64Alphabet[base64Data[dataIndex++]];
647 if ( (b1==-1) ||
648 (b2==-1) ||
649 (b3==-1) ||
650 (b4==-1) )
651 throw new Base64DecodingException("decoding.general");//if found "no data" just return null
652
653
654
655 os.write((byte)( b1 <<2 | b2>>4 ) );
656 os.write((byte)(((b2 & 0xf)<<4 ) |( (b3>>2) & 0xf) ));
657 os.write( (byte)( b3<<6 | b4 ));
658 }
659 b1 = base64Alphabet[base64Data[dataIndex++]];
660 b2 = base64Alphabet[base64Data[dataIndex++]];
661
662 // first last bits.
663 if ((b1==-1) ||
664 (b2==-1) ){
665 throw new Base64DecodingException("decoding.general");//if found "no data" just return null
666 }
667
668 byte d3,d4;
669 b3= base64Alphabet[d3 = base64Data[dataIndex++]];
670 b4= base64Alphabet[d4 = base64Data[dataIndex++]];
671 if ((b3==-1 ) ||
672 (b4==-1) ) {//Check if they are PAD characters
673 if (isPad( d3 ) && isPad( d4)) { //Two PAD e.g. 3c[Pad][Pad]
674 if ((b2 & 0xf) != 0)//last 4 bits should be zero
675 throw new Base64DecodingException("decoding.general");
676 os.write( (byte)( b1 <<2 | b2>>4 ) );
677 } else if (!isPad( d3) && isPad(d4)) { //One PAD e.g. 3cQ[Pad]
678 if ((b3 & 0x3 ) != 0)//last 2 bits should be zero
679 throw new Base64DecodingException("decoding.general");
680 os.write( (byte)( b1 <<2 | b2>>4 ));
681 os.write( (byte)(((b2 & 0xf)<<4 ) |( (b3>>2) & 0xf) ));
682 } else {
683 throw new Base64DecodingException("decoding.general");//an error like "3c[Pad]r", "3cdX", "3cXd", "3cXX" where X is non data
684 }
685 } else {
686 //No PAD e.g 3cQl
687 os.write((byte)( b1 <<2 | b2>>4 ) );
688 os.write( (byte)(((b2 & 0xf)<<4 ) |( (b3>>2) & 0xf) ));
689 os.write((byte)( b3<<6 | b4 ));
690 }
691 return ;
692 }
693
694 /**
695 * Decodes Base64 data into outputstream
696 *
697 * @param is containing Base64 data
698 * @param os the outputstream
699 * @throws IOException
700 * @throws Base64DecodingException
701 */
702 public final static void decode(InputStream is,
703 OutputStream os) throws Base64DecodingException, IOException {
704 //byte decodedData[] = null;
705 byte b1=0,b2=0,b3=0, b4=0;
706
707 int index=0;
708 byte []data=new byte[4];
709 int read;
710 //the begin
711 while ((read=is.read())>0) {
712 byte readed=(byte)read;
713 if (isWhiteSpace(readed)) {
714 continue;
715 }
716 if (isPad(readed)) {
717 data[index++]=readed;
718 if (index==3)
719 data[index++]=(byte)is.read();
720 break;
721 }
722
723
724 if ((data[index++]=readed)==-1) {
725 throw new Base64DecodingException("decoding.general");//if found "no data" just return null
726 }
727
728 if (index!=4) {
729 continue;
730 }
731 index=0;
732 b1 = base64Alphabet[data[0]];
733 b2 = base64Alphabet[data[1]];
734 b3 = base64Alphabet[data[2]];
735 b4 = base64Alphabet[data[3]];
736
737 os.write((byte)( b1 <<2 | b2>>4 ) );
738 os.write((byte)(((b2 & 0xf)<<4 ) |( (b3>>2) & 0xf) ));
739 os.write( (byte)( b3<<6 | b4 ));
740 }
741
742
743 byte d1=data[0],d2=data[1],d3=data[2], d4=data[3];
744 b1 = base64Alphabet[d1];
745 b2 = base64Alphabet[d2];
746 b3 = base64Alphabet[ d3 ];
747 b4 = base64Alphabet[ d4 ];
748 if ((b3==-1 ) ||
749 (b4==-1) ) {//Check if they are PAD characters
750 if (isPad( d3 ) && isPad( d4)) { //Two PAD e.g. 3c[Pad][Pad]
751 if ((b2 & 0xf) != 0)//last 4 bits should be zero
752 throw new Base64DecodingException("decoding.general");
753 os.write( (byte)( b1 <<2 | b2>>4 ) );
754 } else if (!isPad( d3) && isPad(d4)) { //One PAD e.g. 3cQ[Pad]
755 b3 = base64Alphabet[ d3 ];
756 if ((b3 & 0x3 ) != 0)//last 2 bits should be zero
757 throw new Base64DecodingException("decoding.general");
758 os.write( (byte)( b1 <<2 | b2>>4 ));
759 os.write( (byte)(((b2 & 0xf)<<4 ) |( (b3>>2) & 0xf) ));
760 } else {
761 throw new Base64DecodingException("decoding.general");//an error like "3c[Pad]r", "3cdX", "3cXd", "3cXX" where X is non data
762 }
763 } else {
764 //No PAD e.g 3cQl
765
766 os.write((byte)( b1 <<2 | b2>>4 ) );
767 os.write( (byte)(((b2 & 0xf)<<4 ) |( (b3>>2) & 0xf) ));
768 os.write((byte)( b3<<6 | b4 ));
769 }
770
771 return ;
772 }
773 /**
774 * remove WhiteSpace from MIME containing encoded Base64 data.
775 *
776 * @param data the byte array of base64 data (with WS)
777 * @return the new length
778 */
779 protected static final int removeWhiteSpace(byte[] data) {
780 if (data == null)
781 return 0;
782
783 // count characters that's not whitespace
784 int newSize = 0;
785 int len = data.length;
786 for (int i = 0; i < len; i++) {
787 byte dataS=data[i];
788 if (!isWhiteSpace(dataS))
789 data[newSize++] = dataS;
790 }
791 return newSize;
792 }
793 }