1 /*
2 Copyright (C) 2000 - 2007 Grid Systems, S.A.
3
4 This program is free software; you can redistribute it and/or modify
5 it under the terms of the GNU General Public License, version 2, as
6 published by the Free Software Foundation.
7
8 This program is distributed in the hope that it will be useful,
9 but WITHOUT ANY WARRANTY; without even the implied warranty of
10 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
11 GNU General Public License for more details.
12
13 You should have received a copy of the GNU General Public License
14 along with this program; if not, write to the Free Software
15 Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
16 */
17
18 package com.gridsystems;
19
20 import java.io.ByteArrayOutputStream;
21 import java.io.FilterOutputStream;
22 import java.io.IOException;
23 import java.io.InputStream;
24 import java.io.OutputStream;
25
26 /**
27 * A class to encode Base64 streams and strings.
28 * See RFC 1521 section 5.2 for details of the Base64 algorithm.
29 * <p>
30 * This class can be used for encoding strings:
31 * <blockquote><pre>
32 * String unencoded = "webmaster:try2gueSS";
33 * String encoded = Base64Encoder.encode(unencoded);
34 * </pre></blockquote>
35 * or for encoding streams:
36 * <blockquote><pre>
37 * OutputStream out = new Base64Encoder(System.out);
38 * </pre></blockquote>
39 *
40 * @author <b>Jason Hunter</b>, Copyright © 2000
41 * @author Rodrigo Ruiz (modifications for internal use by GridSystems)
42 * @version 1.1, 2000/11/17, fixed bug with sign bit for char values
43 * @version 1.0, 2000/06/11
44 */
45 public class Base64Encoder extends FilterOutputStream {
46
47 /** Mapping from six-bit integers to char values. */
48 private static final char[] CHARS = {
49 'A', 'B', 'C', 'D', 'E', 'F', 'G', 'H', 'I', 'J',
50 'K', 'L', 'M', 'N', 'O', 'P', 'Q', 'R', 'S', 'T',
51 'U', 'V', 'W', 'X', 'Y', 'Z', 'a', 'b', 'c', 'd',
52 'e', 'f', 'g', 'h', 'i', 'j', 'k', 'l', 'm', 'n',
53 'o', 'p', 'q', 'r', 's', 't', 'u', 'v', 'w', 'x',
54 'y', 'z', '0', '1', '2', '3', '4', '5', '6', '7',
55 '8', '9', '+', '/'
56 };
57
58 /** Char count. */
59 private int charCount;
60 /** Carryover. */
61 private int carryOver;
62
63 /**
64 * Constructs a new Base64 encoder that writes output to the given
65 * OutputStream.
66 *
67 * @param out the output stream
68 */
69 public Base64Encoder(OutputStream out) {
70 super(out);
71 }
72
73 /**
74 * Writes the given byte to the output stream in an encoded form.
75 *
76 * @param b the byte to write
77 * @throws IOException if an I/O error occurs
78 */
79 public void write(int b) throws IOException {
80 // Take 24-bits from three octets, translate into four encoded chars
81 // Break lines at 76 chars
82 // If necessary, pad with 0 bits on the right at the end
83 // Use = signs as padding at the end to ensure encodedLength % 4 == 0
84
85 // Remove the sign bit,
86 // thanks to Christian Schweingruber <chrigu@lorraine.ch>
87 if (b < 0) {
88 b += 256;
89 }
90
91 // First byte use first six bits, save last two bits
92 if (charCount % 3 == 0) {
93 int lookup = b >> 2;
94 carryOver = b & 3; // last two bits
95 out.write(CHARS[lookup]);
96 } else if (charCount % 3 == 1) {
97 // Second byte use previous two bits and first four new bits,
98 // save last four bits
99 int lookup = ((carryOver << 4) + (b >> 4)) & 63;
100 carryOver = b & 15; // last four bits
101 out.write(CHARS[lookup]);
102 } else if (charCount % 3 == 2) {
103 // Third byte use previous four bits and first two new bits,
104 // then use last six new bits
105 int lookup = ((carryOver << 2) + (b >> 6)) & 63;
106 out.write(CHARS[lookup]);
107 lookup = b & 63; // last six bits
108 out.write(CHARS[lookup]);
109 carryOver = 0;
110 }
111 charCount++;
112
113 // Add newline every 76 output chars (that's 57 input chars)
114 if (charCount % 57 == 0) {
115 out.write('\n');
116 }
117 }
118
119 /**
120 * Writes the given byte array to the output stream in an
121 * encoded form.
122 *
123 * @param b the data to be written
124 * @param off the start offset of the data
125 * @param len the length of the data
126 * @exception IOException if an I/O error occurs
127 */
128 public void write(byte[] b, int off, int len) throws IOException {
129 // This could of course be optimized
130 for (int i = 0; i < len; i++) {
131 write(b[off + i]);
132 }
133 }
134
135 /**
136 * Write a String to the output stream.
137 * @param s the string to write
138 * @throws IOException if an I/O error occurs
139 */
140 public void write(String s) throws IOException {
141 byte[] buf = Base64Utils.toByteArray(s);
142 write(buf, 0, buf.length);
143 }
144
145 /**
146 * Closes the stream, this MUST be called to ensure proper padding is
147 * written to the end of the output stream.
148 *
149 * @exception IOException if an I/O error occurs
150 */
151 public void close() throws IOException {
152 // Handle leftover bytes
153 if (charCount % 3 == 1) { // one leftover
154 int lookup = (carryOver << 4) & 63;
155 out.write(CHARS[lookup]);
156 out.write('=');
157 out.write('=');
158 } else if (charCount % 3 == 2) { // two leftovers
159 int lookup = (carryOver << 2) & 63;
160 out.write(CHARS[lookup]);
161 out.write('=');
162 }
163 super.close();
164 }
165
166 /**
167 * Returns the Base64 encoded form of the given string.
168 *
169 * @param s the string to encode
170 * @return the encoded form of the unencoded string
171 */
172 public static String encode(String s) {
173 ByteArrayOutputStream out = new ByteArrayOutputStream((int) (s.length() * 1.37));
174 Base64Encoder encodedOut = new Base64Encoder(out);
175
176 try {
177 encodedOut.write(s);
178 encodedOut.close();
179
180 // No need to specify a character encoding. Base64 uses a subset of ASCII
181 return out.toString();
182 } catch (IOException ignored) { return null; }
183 }
184
185 /**
186 * Returns the encoded form of the given unencoded byte array.
187 *
188 * @param unencoded the byte array to encode
189 * @return the encoded form of the unencoded byte array
190 */
191 public static byte[] binaryEncode(byte[] unencoded) {
192 ByteArrayOutputStream out = new ByteArrayOutputStream((int)(unencoded.length * 1.37));
193 Base64Encoder encodedOut = new Base64Encoder(out);
194
195 try {
196 encodedOut.write(unencoded);
197 encodedOut.close();
198
199 return out.toByteArray();
200 } catch (IOException ignored) { return null; }
201 }
202
203 /**
204 * Returns the encoded form of the given unencoded byte array.
205 *
206 * @param is the input stream to encode
207 * @return the encoded form of the unencoded byte array
208 */
209 public static byte[] binaryEncode(InputStream is) {
210 ByteArrayOutputStream out = new ByteArrayOutputStream();
211 Base64Encoder encodedOut = new Base64Encoder(out);
212
213 try {
214 byte[] data = new byte[128000];
215
216 int size;
217
218 while ((size = is.read(data)) != -1) {
219 encodedOut.write(data, 0, size);
220 }
221 encodedOut.close();
222
223 byte[] retorno = out.toByteArray();
224 out = null;
225
226 return retorno;
227 } catch (IOException ignored) { return null; }
228 }
229 }