1 /*
2 * Copyright (c) 1997, 2013, 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 }