1/* 2 * reserved comment block 3 * DO NOT REMOVE OR ALTER! 4 */ 5/* 6 * Licensed to the Apache Software Foundation (ASF) under one or more 7 * contributor license agreements. See the NOTICE file distributed with 8 * this work for additional information regarding copyright ownership. 9 * The ASF licenses this file to You under the Apache License, Version 2.0 10 * (the "License"); you may not use this file except in compliance with 11 * the License. You may obtain a copy of the License at 12 * 13 * http://www.apache.org/licenses/LICENSE-2.0 14 * 15 * Unless required by applicable law or agreed to in writing, software 16 * distributed under the License is distributed on an "AS IS" BASIS, 17 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 18 * See the License for the specific language governing permissions and 19 * limitations under the License. 20 */ 21 22package com.sun.org.apache.xerces.internal.impl.dv.util; 23 24/** 25 * This class provides encode/decode for RFC 2045 Base64 as 26 * defined by RFC 2045, N. Freed and N. Borenstein. 27 * RFC 2045: Multipurpose Internet Mail Extensions (MIME) 28 * Part One: Format of Internet Message Bodies. Reference 29 * 1996 Available at: http://www.ietf.org/rfc/rfc2045.txt 30 * This class is used by XML Schema binary format validation 31 * 32 * This implementation does not encode/decode streaming 33 * data. You need the data that you will encode/decode 34 * already on a byte arrray. 35 * 36 * @xerces.internal 37 * 38 * @author Jeffrey Rodriguez 39 * @author Sandy Gao 40 */ 41public final class Base64 { 42 43 static private final int BASELENGTH = 128; 44 static private final int LOOKUPLENGTH = 64; 45 static private final int TWENTYFOURBITGROUP = 24; 46 static private final int EIGHTBIT = 8; 47 static private final int SIXTEENBIT = 16; 48 static private final int SIXBIT = 6; 49 static private final int FOURBYTE = 4; 50 static private final int SIGN = -128; 51 static private final char PAD = '='; 52 static private final boolean fDebug = false; 53 static final private byte [] base64Alphabet = new byte[BASELENGTH]; 54 static final private char [] lookUpBase64Alphabet = new char[LOOKUPLENGTH]; 55 56 static { 57 58 for (int i = 0; i < BASELENGTH; ++i) { 59 base64Alphabet[i] = -1; 60 } 61 for (int i = 'Z'; i >= 'A'; i--) { 62 base64Alphabet[i] = (byte) (i-'A'); 63 } 64 for (int i = 'z'; i>= 'a'; i--) { 65 base64Alphabet[i] = (byte) ( i-'a' + 26); 66 } 67 68 for (int i = '9'; i >= '0'; i--) { 69 base64Alphabet[i] = (byte) (i-'0' + 52); 70 } 71 72 base64Alphabet['+'] = 62; 73 base64Alphabet['/'] = 63; 74 75 for (int i = 0; i<=25; i++) 76 lookUpBase64Alphabet[i] = (char)('A'+i); 77 78 for (int i = 26, j = 0; i<=51; i++, j++) 79 lookUpBase64Alphabet[i] = (char)('a'+ j); 80 81 for (int i = 52, j = 0; i<=61; i++, j++) 82 lookUpBase64Alphabet[i] = (char)('0' + j); 83 lookUpBase64Alphabet[62] = (char)'+'; 84 lookUpBase64Alphabet[63] = (char)'/'; 85 86 } 87 88 protected static boolean isWhiteSpace(char octect) { 89 return (octect == 0x20 || octect == 0xd || octect == 0xa || octect == 0x9); 90 } 91 92 protected static boolean isPad(char octect) { 93 return (octect == PAD); 94 } 95 96 protected static boolean isData(char octect) { 97 return (octect < BASELENGTH && base64Alphabet[octect] != -1); 98 } 99 100 protected static boolean isBase64(char octect) { 101 return (isWhiteSpace(octect) || isPad(octect) || isData(octect)); 102 } 103 104 /** 105 * Encodes hex octects into Base64 106 * 107 * @param binaryData Array containing binaryData 108 * @return Encoded Base64 array 109 */ 110 public static String encode(byte[] binaryData) { 111 112 if (binaryData == null) 113 return null; 114 115 int lengthDataBits = binaryData.length*EIGHTBIT; 116 if (lengthDataBits == 0) { 117 return ""; 118 } 119 120 int fewerThan24bits = lengthDataBits%TWENTYFOURBITGROUP; 121 int numberTriplets = lengthDataBits/TWENTYFOURBITGROUP; 122 int numberQuartet = fewerThan24bits != 0 ? numberTriplets+1 : numberTriplets; 123 char encodedData[] = null; 124 125 encodedData = new char[numberQuartet*4]; 126 127 byte k=0, l=0, b1=0,b2=0,b3=0; 128 129 int encodedIndex = 0; 130 int dataIndex = 0; 131 if (fDebug) { 132 System.out.println("number of triplets = " + numberTriplets ); 133 } 134 135 for (int i=0; i<numberTriplets; i++) { 136 b1 = binaryData[dataIndex++]; 137 b2 = binaryData[dataIndex++]; 138 b3 = binaryData[dataIndex++]; 139 140 if (fDebug) { 141 System.out.println( "b1= " + b1 +", b2= " + b2 + ", b3= " + b3 ); 142 } 143 144 l = (byte)(b2 & 0x0f); 145 k = (byte)(b1 & 0x03); 146 147 byte val1 = ((b1 & SIGN)==0)?(byte)(b1>>2):(byte)((b1)>>2^0xc0); 148 149 byte val2 = ((b2 & SIGN)==0)?(byte)(b2>>4):(byte)((b2)>>4^0xf0); 150 byte val3 = ((b3 & SIGN)==0)?(byte)(b3>>6):(byte)((b3)>>6^0xfc); 151 152 if (fDebug) { 153 System.out.println( "val2 = " + val2 ); 154 System.out.println( "k4 = " + (k<<4)); 155 System.out.println( "vak = " + (val2 | (k<<4))); 156 } 157 158 encodedData[encodedIndex++] = lookUpBase64Alphabet[ val1 ]; 159 encodedData[encodedIndex++] = lookUpBase64Alphabet[ val2 | ( k<<4 )]; 160 encodedData[encodedIndex++] = lookUpBase64Alphabet[ (l <<2 ) | val3 ]; 161 encodedData[encodedIndex++] = lookUpBase64Alphabet[ b3 & 0x3f ]; 162 } 163 164 // form integral number of 6-bit groups 165 if (fewerThan24bits == EIGHTBIT) { 166 b1 = binaryData[dataIndex]; 167 k = (byte) ( b1 &0x03 ); 168 if (fDebug) { 169 System.out.println("b1=" + b1); 170 System.out.println("b1<<2 = " + (b1>>2) ); 171 } 172 byte val1 = ((b1 & SIGN)==0)?(byte)(b1>>2):(byte)((b1)>>2^0xc0); 173 encodedData[encodedIndex++] = lookUpBase64Alphabet[ val1 ]; 174 encodedData[encodedIndex++] = lookUpBase64Alphabet[ k<<4 ]; 175 encodedData[encodedIndex++] = PAD; 176 encodedData[encodedIndex++] = PAD; 177 } else if (fewerThan24bits == SIXTEENBIT) { 178 b1 = binaryData[dataIndex]; 179 b2 = binaryData[dataIndex +1 ]; 180 l = ( byte ) ( b2 &0x0f ); 181 k = ( byte ) ( b1 &0x03 ); 182 183 byte val1 = ((b1 & SIGN)==0)?(byte)(b1>>2):(byte)((b1)>>2^0xc0); 184 byte val2 = ((b2 & SIGN)==0)?(byte)(b2>>4):(byte)((b2)>>4^0xf0); 185 186 encodedData[encodedIndex++] = lookUpBase64Alphabet[ val1 ]; 187 encodedData[encodedIndex++] = lookUpBase64Alphabet[ val2 | ( k<<4 )]; 188 encodedData[encodedIndex++] = lookUpBase64Alphabet[ l<<2 ]; 189 encodedData[encodedIndex++] = PAD; 190 } 191 192 return new String(encodedData); 193 } 194 195 /** 196 * Decodes Base64 data into octects 197 * 198 * @param encoded string containing Base64 data 199 * @return Array containind decoded data. 200 */ 201 public static byte[] decode(String encoded) { 202 203 if (encoded == null) 204 return null; 205 206 char[] base64Data = encoded.toCharArray(); 207 // remove white spaces 208 int len = removeWhiteSpace(base64Data); 209 210 if (len%FOURBYTE != 0) { 211 return null;//should be divisible by four 212 } 213 214 int numberQuadruple = (len/FOURBYTE ); 215 216 if (numberQuadruple == 0) 217 return new byte[0]; 218 219 byte decodedData[] = null; 220 byte b1=0,b2=0,b3=0,b4=0; 221 char d1=0,d2=0,d3=0,d4=0; 222 223 int i = 0; 224 int encodedIndex = 0; 225 int dataIndex = 0; 226 decodedData = new byte[ (numberQuadruple)*3]; 227 228 for (; i<numberQuadruple-1; i++) { 229 230 if (!isData( (d1 = base64Data[dataIndex++]) )|| 231 !isData( (d2 = base64Data[dataIndex++]) )|| 232 !isData( (d3 = base64Data[dataIndex++]) )|| 233 !isData( (d4 = base64Data[dataIndex++]) )) 234 return null;//if found "no data" just return null 235 236 b1 = base64Alphabet[d1]; 237 b2 = base64Alphabet[d2]; 238 b3 = base64Alphabet[d3]; 239 b4 = base64Alphabet[d4]; 240 241 decodedData[encodedIndex++] = (byte)( b1 <<2 | b2>>4 ) ; 242 decodedData[encodedIndex++] = (byte)(((b2 & 0xf)<<4 ) |( (b3>>2) & 0xf) ); 243 decodedData[encodedIndex++] = (byte)( b3<<6 | b4 ); 244 } 245 246 if (!isData( (d1 = base64Data[dataIndex++]) ) || 247 !isData( (d2 = base64Data[dataIndex++]) )) { 248 return null;//if found "no data" just return null 249 } 250 251 b1 = base64Alphabet[d1]; 252 b2 = base64Alphabet[d2]; 253 254 d3 = base64Data[dataIndex++]; 255 d4 = base64Data[dataIndex++]; 256 if (!isData( (d3 ) ) || 257 !isData( (d4 ) )) {//Check if they are PAD characters 258 if (isPad( d3 ) && isPad( d4)) { //Two PAD e.g. 3c[Pad][Pad] 259 if ((b2 & 0xf) != 0)//last 4 bits should be zero 260 return null; 261 byte[] tmp = new byte[ i*3 + 1 ]; 262 System.arraycopy( decodedData, 0, tmp, 0, i*3 ); 263 tmp[encodedIndex] = (byte)( b1 <<2 | b2>>4 ) ; 264 return tmp; 265 } else if (!isPad( d3) && isPad(d4)) { //One PAD e.g. 3cQ[Pad] 266 b3 = base64Alphabet[ d3 ]; 267 if ((b3 & 0x3 ) != 0)//last 2 bits should be zero 268 return null; 269 byte[] tmp = new byte[ i*3 + 2 ]; 270 System.arraycopy( decodedData, 0, tmp, 0, i*3 ); 271 tmp[encodedIndex++] = (byte)( b1 <<2 | b2>>4 ); 272 tmp[encodedIndex] = (byte)(((b2 & 0xf)<<4 ) |( (b3>>2) & 0xf) ); 273 return tmp; 274 } else { 275 return null;//an error like "3c[Pad]r", "3cdX", "3cXd", "3cXX" where X is non data 276 } 277 } else { //No PAD e.g 3cQl 278 b3 = base64Alphabet[ d3 ]; 279 b4 = base64Alphabet[ d4 ]; 280 decodedData[encodedIndex++] = (byte)( b1 <<2 | b2>>4 ) ; 281 decodedData[encodedIndex++] = (byte)(((b2 & 0xf)<<4 ) |( (b3>>2) & 0xf) ); 282 decodedData[encodedIndex++] = (byte)( b3<<6 | b4 ); 283 284 } 285 286 return decodedData; 287 } 288 289 /** 290 * remove WhiteSpace from MIME containing encoded Base64 data. 291 * 292 * @param data the byte array of base64 data (with WS) 293 * @return the new length 294 */ 295 protected static int removeWhiteSpace(char[] data) { 296 if (data == null) 297 return 0; 298 299 // count characters that's not whitespace 300 int newSize = 0; 301 int len = data.length; 302 for (int i = 0; i < len; i++) { 303 if (!isWhiteSpace(data[i])) 304 data[newSize++] = data[i]; 305 } 306 return newSize; 307 } 308} 309