1 /*
2 * Copyright (c) 1997, 2017, 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 @Override
84 public void write(byte[] b, int off, int len) throws IOException {
85 for (int i = 0; i < len; i++)
86 write(b[off + i]);
87 }
88
89 /**
90 * Encodes <code>b.length</code> bytes to this output stream.
91 * @param b the data to be written.
92 * @exception IOException if an I/O error occurs.
93 */
94 @Override
95 public void write(byte[] b) throws IOException {
96 write(b, 0, b.length);
97 }
98
99 /**
100 * Encodes the specified <code>byte</code> to this output stream.
101 * @param c the <code>byte</code>.
102 * @exception IOException if an I/O error occurs.
103 */
104 @Override
105 public void write(int c) throws IOException {
106 buffer[bufsize++] = (byte)c;
107 if (bufsize == 3) { // Encoding unit = 3 bytes
108 encode();
109 bufsize = 0;
110 }
111 }
112
113 /**
114 * Flushes this output stream and forces any buffered output bytes
115 * to be encoded out to the stream.
116 * @exception IOException if an I/O error occurs.
117 */
118 @Override
119 public void flush() throws IOException {
120 if (bufsize > 0) { // If there's unencoded characters in the buffer ..
121 encode(); // .. encode them
122 bufsize = 0;
123 }
124 out.flush();
125 }
126
127 /**
128 * Forces any buffered output bytes to be encoded out to the stream
129 * and closes this output stream
130 */
131 @Override
132 public void close() throws IOException {
133 flush();
134 out.close();
135 }
136
137 /** This array maps the characters to their 6 bit values */
138 private final static char pem_array[] = {
139 'A','B','C','D','E','F','G','H', // 0
140 'I','J','K','L','M','N','O','P', // 1
141 'Q','R','S','T','U','V','W','X', // 2
142 'Y','Z','a','b','c','d','e','f', // 3
143 'g','h','i','j','k','l','m','n', // 4
144 'o','p','q','r','s','t','u','v', // 5
145 'w','x','y','z','0','1','2','3', // 6
146 '4','5','6','7','8','9','+','/' // 7
147 };
148
149 private void encode() throws IOException {
150 // If writing out this encoded unit will cause overflow,
151 // start a new line.
152 if (count + 4 > bytesPerLine) {
153 out.write('\r');
154 out.write('\n');
155 count = 0;
156 }
157
158 byte a, b, c;
159 if (bufsize == 1) {
160 a = buffer[0];
161 b = 0;
162 c = 0;
163 out.write(pem_array[(a >>> 2) & 0x3F]);
164 out.write(pem_array[((a << 4) & 0x30) + ((b >>> 4) & 0xf)]);
165 out.write('='); // pad character
166 out.write('='); // pad character
167 } else if (bufsize == 2) {
168 a = buffer[0];
169 b = buffer[1];
170 c = 0;
171 out.write(pem_array[(a >>> 2) & 0x3F]);
172 out.write(pem_array[((a << 4) & 0x30) + ((b >>> 4) & 0xf)]);
173 out.write(pem_array[((b << 2) & 0x3c) + ((c >>> 6) & 0x3)]);
174 out.write('='); // pad character
175 } else {
176 a = buffer[0];
177 b = buffer[1];
178 c = buffer[2];
179 out.write(pem_array[(a >>> 2) & 0x3F]);
180 out.write(pem_array[((a << 4) & 0x30) + ((b >>> 4) & 0xf)]);
181 out.write(pem_array[((b << 2) & 0x3c) + ((c >>> 6) & 0x3)]);
182 out.write(pem_array[c & 0x3F]);
183 }
184
185 // increment count
186 count += 4;
187 }
188
189 /**
190 * Base64 encode a byte array. No line breaks are inserted.
191 * This method is suitable for short strings, such as those
192 * in the IMAP AUTHENTICATE protocol, but not to encode the
193 * entire content of a MIME part.
194 *
195 * @param inbuf byte array to encode.
196 *
197 * @return encoded byte array.
198 */
199 public static byte[] encode(byte[] inbuf) {
200 if (inbuf.length == 0)
201 return inbuf;
202 byte[] outbuf = new byte[((inbuf.length + 2) / 3) * 4];
203 int inpos = 0, outpos = 0;
204 int size = inbuf.length;
205 while (size > 0) {
206 byte a, b, c;
207 if (size == 1) {
208 a = inbuf[inpos++];
209 b = 0;
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++] = (byte)'='; // pad character
215 outbuf[outpos++] = (byte)'='; // pad character
216 } else if (size == 2) {
217 a = inbuf[inpos++];
218 b = inbuf[inpos++];
219 c = 0;
220 outbuf[outpos++] = (byte)pem_array[(a >>> 2) & 0x3F];
221 outbuf[outpos++] =
222 (byte)pem_array[((a << 4) & 0x30) + ((b >>> 4) & 0xf)];
223 outbuf[outpos++] =
224 (byte)pem_array[((b << 2) & 0x3c) + ((c >>> 6) & 0x3)];
225 outbuf[outpos++] = (byte)'='; // pad character
226 } else {
227 a = inbuf[inpos++];
228 b = inbuf[inpos++];
229 c = inbuf[inpos++];
230 outbuf[outpos++] = (byte)pem_array[(a >>> 2) & 0x3F];
231 outbuf[outpos++] =
232 (byte)pem_array[((a << 4) & 0x30) + ((b >>> 4) & 0xf)];
233 outbuf[outpos++] =
234 (byte)pem_array[((b << 2) & 0x3c) + ((c >>> 6) & 0x3)];
235 outbuf[outpos++] = (byte)pem_array[c & 0x3F];
236 }
237 size -= 3;
238 }
239 return outbuf;
240 }
241
242 /*** begin TEST program
243 public static void main(String argv[]) throws Exception {
244 FileInputStream infile = new FileInputStream(argv[0]);
245 BASE64EncoderStream encoder = new BASE64EncoderStream(System.out);
246 int c;
247
248 while ((c = infile.read()) != -1)
249 encoder.write(c);
250 encoder.close();
251 }
252 *** end TEST program **/
253 }