1 /* 2 * Copyright (c) 1997, 2012, Oracle and/or its affiliates. All rights reserved. 3 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. 4 * 5 * This code is free software; you can redistribute it and/or modify it 6 * under the terms of the GNU General Public License version 2 only, as 7 * published by the Free Software Foundation. Oracle designates this 8 * particular file as subject to the "Classpath" exception as provided 9 * by Oracle in the LICENSE file that accompanied this code. 10 * 11 * This code is distributed in the hope that it will be useful, but WITHOUT 12 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or 13 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License 14 * version 2 for more details (a copy is included in the LICENSE file that 15 * accompanied this code). 16 * 17 * You should have received a copy of the GNU General Public License version 18 * 2 along with this work; if not, write to the Free Software Foundation, 19 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. 20 * 21 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA 22 * or visit www.oracle.com if you need additional information or have any 23 * questions. 24 */ 25 26 /* 27 * @(#)BASE64EncoderStream.java 1.6 02/03/27 28 */ 29 30 31 32 package com.sun.xml.internal.messaging.saaj.packaging.mime.util; 33 34 import java.io.*; 35 36 /** 37 * This class implements a BASE64 Encoder. It is implemented as 38 * a FilterOutputStream, so one can just wrap this class around 39 * any output stream and write bytes into this filter. The Encoding 40 * is done as the bytes are written out. 41 * 42 * @author John Mani 43 * @author Bill Shannon 44 */ 45 46 public class BASE64EncoderStream extends FilterOutputStream { 47 private byte[] buffer; // cache of bytes that are yet to be encoded 48 private int bufsize = 0; // size of the cache 49 private int count = 0; // number of bytes that have been output 50 private int bytesPerLine; // number of bytes per line 51 52 /** 53 * Create a BASE64 encoder that encodes the specified input stream 54 * @param out the output stream 55 * @param bytesPerLine number of bytes per line. The encoder inserts 56 * a CRLF sequence after the specified number of bytes 57 */ 58 public BASE64EncoderStream(OutputStream out, int bytesPerLine) { 59 super(out); 60 buffer = new byte[3]; 61 this.bytesPerLine = bytesPerLine; 62 } 63 64 /** 65 * Create a BASE64 encoder that encodes the specified input stream. 66 * Inserts the CRLF sequence after outputting 76 bytes. 67 * @param out the output stream 68 */ 69 public BASE64EncoderStream(OutputStream out) { 70 this(out, 76); 71 } 72 73 /** 74 * Encodes <code>len</code> bytes from the specified 75 * <code>byte</code> array starting at offset <code>off</code> to 76 * this output stream. 77 * 78 * @param b the data. 79 * @param off the start offset in the data. 80 * @param len the number of bytes to write. 81 * @exception IOException if an I/O error occurs. 82 */ 83 public void write(byte[] b, int off, int len) throws IOException { 84 for (int i = 0; i < len; i++) 85 write(b[off + i]); 86 } 87 88 /** 89 * Encodes <code>b.length</code> bytes to this output stream. 90 * @param b the data to be written. 91 * @exception IOException if an I/O error occurs. 92 */ 93 public void write(byte[] b) throws IOException { 94 write(b, 0, b.length); 95 } 96 97 /** 98 * Encodes the specified <code>byte</code> to this output stream. 99 * @param c the <code>byte</code>. 100 * @exception IOException if an I/O error occurs. 101 */ 102 public void write(int c) throws IOException { 103 buffer[bufsize++] = (byte)c; 104 if (bufsize == 3) { // Encoding unit = 3 bytes 105 encode(); 106 bufsize = 0; 107 } 108 } 109 110 /** 111 * Flushes this output stream and forces any buffered output bytes 112 * to be encoded out to the stream. 113 * @exception IOException if an I/O error occurs. 114 */ 115 public void flush() throws IOException { 116 if (bufsize > 0) { // If there's unencoded characters in the buffer .. 117 encode(); // .. encode them 118 bufsize = 0; 119 } 120 out.flush(); 121 } 122 123 /** 124 * Forces any buffered output bytes to be encoded out to the stream 125 * and closes this output stream 126 */ 127 public void close() throws IOException { 128 flush(); 129 out.close(); 130 } 131 132 /** This array maps the characters to their 6 bit values */ 133 private final static char pem_array[] = { 134 'A','B','C','D','E','F','G','H', // 0 135 'I','J','K','L','M','N','O','P', // 1 136 'Q','R','S','T','U','V','W','X', // 2 137 'Y','Z','a','b','c','d','e','f', // 3 138 'g','h','i','j','k','l','m','n', // 4 139 'o','p','q','r','s','t','u','v', // 5 140 'w','x','y','z','0','1','2','3', // 6 141 '4','5','6','7','8','9','+','/' // 7 142 }; 143 144 private void encode() throws IOException { 145 // If writing out this encoded unit will cause overflow, 146 // start a new line. 147 if (count + 4 > bytesPerLine) { 148 out.write('\r'); 149 out.write('\n'); 150 count = 0; 151 } 152 153 byte a, b, c; 154 if (bufsize == 1) { 155 a = buffer[0]; 156 b = 0; 157 c = 0; 158 out.write(pem_array[(a >>> 2) & 0x3F]); 159 out.write(pem_array[((a << 4) & 0x30) + ((b >>> 4) & 0xf)]); 160 out.write('='); // pad character 161 out.write('='); // pad character 162 } else if (bufsize == 2) { 163 a = buffer[0]; 164 b = buffer[1]; 165 c = 0; 166 out.write(pem_array[(a >>> 2) & 0x3F]); 167 out.write(pem_array[((a << 4) & 0x30) + ((b >>> 4) & 0xf)]); 168 out.write(pem_array[((b << 2) & 0x3c) + ((c >>> 6) & 0x3)]); 169 out.write('='); // pad character 170 } else { 171 a = buffer[0]; 172 b = buffer[1]; 173 c = buffer[2]; 174 out.write(pem_array[(a >>> 2) & 0x3F]); 175 out.write(pem_array[((a << 4) & 0x30) + ((b >>> 4) & 0xf)]); 176 out.write(pem_array[((b << 2) & 0x3c) + ((c >>> 6) & 0x3)]); 177 out.write(pem_array[c & 0x3F]); 178 } 179 180 // increment count 181 count += 4; 182 } 183 184 /** 185 * Base64 encode a byte array. No line breaks are inserted. 186 * This method is suitable for short strings, such as those 187 * in the IMAP AUTHENTICATE protocol, but not to encode the 188 * entire content of a MIME part. 189 */ 190 public static byte[] encode(byte[] inbuf) { 191 if (inbuf.length == 0) 192 return inbuf; 193 byte[] outbuf = new byte[((inbuf.length + 2) / 3) * 4]; 194 int inpos = 0, outpos = 0; 195 int size = inbuf.length; 196 while (size > 0) { 197 byte a, b, c; 198 if (size == 1) { 199 a = inbuf[inpos++]; 200 b = 0; 201 c = 0; 202 outbuf[outpos++] = (byte)pem_array[(a >>> 2) & 0x3F]; 203 outbuf[outpos++] = 204 (byte)pem_array[((a << 4) & 0x30) + ((b >>> 4) & 0xf)]; 205 outbuf[outpos++] = (byte)'='; // pad character 206 outbuf[outpos++] = (byte)'='; // pad character 207 } else if (size == 2) { 208 a = inbuf[inpos++]; 209 b = inbuf[inpos++]; 210 c = 0; 211 outbuf[outpos++] = (byte)pem_array[(a >>> 2) & 0x3F]; 212 outbuf[outpos++] = 213 (byte)pem_array[((a << 4) & 0x30) + ((b >>> 4) & 0xf)]; 214 outbuf[outpos++] = 215 (byte)pem_array[((b << 2) & 0x3c) + ((c >>> 6) & 0x3)]; 216 outbuf[outpos++] = (byte)'='; // pad character 217 } else { 218 a = inbuf[inpos++]; 219 b = inbuf[inpos++]; 220 c = inbuf[inpos++]; 221 outbuf[outpos++] = (byte)pem_array[(a >>> 2) & 0x3F]; 222 outbuf[outpos++] = 223 (byte)pem_array[((a << 4) & 0x30) + ((b >>> 4) & 0xf)]; 224 outbuf[outpos++] = 225 (byte)pem_array[((b << 2) & 0x3c) + ((c >>> 6) & 0x3)]; 226 outbuf[outpos++] = (byte)pem_array[c & 0x3F]; 227 } 228 size -= 3; 229 } 230 return outbuf; 231 } 232 233 /*** begin TEST program 234 public static void main(String argv[]) throws Exception { 235 FileInputStream infile = new FileInputStream(argv[0]); 236 BASE64EncoderStream encoder = new BASE64EncoderStream(System.out); 237 int c; 238 239 while ((c = infile.read()) != -1) 240 encoder.write(c); 241 encoder.close(); 242 } 243 *** end TEST program **/ 244 }