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1 // Copyright 2003-2010 Christian d'Heureuse, Inventec Informatik AG, Zurich, Switzerland
2 // www.source-code.biz, www.inventec.ch/chdh
3 //
4 // This module is multi-licensed and may be used under the terms
5 // of any of the following licenses:
6 //
7 //  EPL, Eclipse Public License, V1.0 or later, http://www.eclipse.org/legal
8 //  LGPL, GNU Lesser General Public License, V2.1 or later, http://www.gnu.org/licenses/lgpl.html
9 //  GPL, GNU General Public License, V2 or later, http://www.gnu.org/licenses/gpl.html
10 //  AL, Apache License, V2.0 or later, http://www.apache.org/licenses
11 //  BSD, BSD License, http://www.opensource.org/licenses/bsd-license.php
12 //
13 // Please contact the author if you need another license.
14 // This module is provided "as is", without warranties of any kind.
15 
16 package org.yaml.snakeyaml.external.biz.base64Coder;
17 
18 /**
19  * A Base64 encoder/decoder.
20  *
21  * <p>
22  * This class is used to encode and decode data in Base64 format as described in
23  * RFC 1521.
24  *
25  * <p>
26  * Project home page: <a
27  * href="http://www.source-code.biz/base64coder/java/">www.
28  * source-code.biz/base64coder/java</a><br>
29  * Author: Christian d'Heureuse, Inventec Informatik AG, Zurich, Switzerland<br>
30  * Multi-licensed: EPL / LGPL / GPL / AL / BSD.
31  */
32 public class Base64Coder {
33 
34     // The line separator string of the operating system.
35     private static final String systemLineSeparator = System.getProperty("line.separator");
36 
37     // Mapping table from 6-bit nibbles to Base64 characters.
38     private static char[] map1 = new char[64];
39     static {
40         int i = 0;
41         for (char c = 'A'; c <= 'Z'; c++)
42             map1[i++] = c;
43         for (char c = 'a'; c <= 'z'; c++)
44             map1[i++] = c;
45         for (char c = '0'; c <= '9'; c++)
46             map1[i++] = c;
47         map1[i++] = '+';
48         map1[i++] = '/';
49     }
50 
51     // Mapping table from Base64 characters to 6-bit nibbles.
52     private static byte[] map2 = new byte[128];
53     static {
54         for (int i = 0; i < map2.length; i++)
55             map2[i] = -1;
56         for (int i = 0; i < 64; i++)
57             map2[map1[i]] = (byte) i;
58     }
59 
60     /**
61      * Encodes a string into Base64 format. No blanks or line breaks are
62      * inserted.
63      *
64      * @param s
65      *            A String to be encoded.
66      * @return A String containing the Base64 encoded data.
67      */
encodeString(String s)68     public static String encodeString(String s) {
69         return new String(encode(s.getBytes()));
70     }
71 
72     /**
73      * Encodes a byte array into Base 64 format and breaks the output into lines
74      * of 76 characters. This method is compatible with
75      * <code>sun.misc.BASE64Encoder.encodeBuffer(byte[])</code>.
76      *
77      * @param in
78      *            An array containing the data bytes to be encoded.
79      * @return A String containing the Base64 encoded data, broken into lines.
80      */
encodeLines(byte[] in)81     public static String encodeLines(byte[] in) {
82         return encodeLines(in, 0, in.length, 76, systemLineSeparator);
83     }
84 
85     /**
86      * Encodes a byte array into Base 64 format and breaks the output into
87      * lines.
88      *
89      * @param in
90      *            An array containing the data bytes to be encoded.
91      * @param iOff
92      *            Offset of the first byte in <code>in</code> to be processed.
93      * @param iLen
94      *            Number of bytes to be processed in <code>in</code>, starting
95      *            at <code>iOff</code>.
96      * @param lineLen
97      *            Line length for the output data. Should be a multiple of 4.
98      * @param lineSeparator
99      *            The line separator to be used to separate the output lines.
100      * @return A String containing the Base64 encoded data, broken into lines.
101      */
encodeLines(byte[] in, int iOff, int iLen, int lineLen, String lineSeparator)102     public static String encodeLines(byte[] in, int iOff, int iLen, int lineLen,
103             String lineSeparator) {
104         int blockLen = (lineLen * 3) / 4;
105         if (blockLen <= 0)
106             throw new IllegalArgumentException();
107         int lines = (iLen + blockLen - 1) / blockLen;
108         int bufLen = ((iLen + 2) / 3) * 4 + lines * lineSeparator.length();
109         StringBuilder buf = new StringBuilder(bufLen);
110         int ip = 0;
111         while (ip < iLen) {
112             int l = Math.min(iLen - ip, blockLen);
113             buf.append(encode(in, iOff + ip, l));
114             buf.append(lineSeparator);
115             ip += l;
116         }
117         return buf.toString();
118     }
119 
120     /**
121      * Encodes a byte array into Base64 format. No blanks or line breaks are
122      * inserted in the output.
123      *
124      * @param in
125      *            An array containing the data bytes to be encoded.
126      * @return A character array containing the Base64 encoded data.
127      */
encode(byte[] in)128     public static char[] encode(byte[] in) {
129         return encode(in, 0, in.length);
130     }
131 
132     /**
133      * Encodes a byte array into Base64 format. No blanks or line breaks are
134      * inserted in the output.
135      *
136      * @param in
137      *            An array containing the data bytes to be encoded.
138      * @param iLen
139      *            Number of bytes to process in <code>in</code>.
140      * @return A character array containing the Base64 encoded data.
141      */
encode(byte[] in, int iLen)142     public static char[] encode(byte[] in, int iLen) {
143         return encode(in, 0, iLen);
144     }
145 
146     /**
147      * Encodes a byte array into Base64 format. No blanks or line breaks are
148      * inserted in the output.
149      *
150      * @param in
151      *            An array containing the data bytes to be encoded.
152      * @param iOff
153      *            Offset of the first byte in <code>in</code> to be processed.
154      * @param iLen
155      *            Number of bytes to process in <code>in</code>, starting at
156      *            <code>iOff</code>.
157      * @return A character array containing the Base64 encoded data.
158      */
encode(byte[] in, int iOff, int iLen)159     public static char[] encode(byte[] in, int iOff, int iLen) {
160         int oDataLen = (iLen * 4 + 2) / 3; // output length without padding
161         int oLen = ((iLen + 2) / 3) * 4; // output length including padding
162         char[] out = new char[oLen];
163         int ip = iOff;
164         int iEnd = iOff + iLen;
165         int op = 0;
166         while (ip < iEnd) {
167             int i0 = in[ip++] & 0xff;
168             int i1 = ip < iEnd ? in[ip++] & 0xff : 0;
169             int i2 = ip < iEnd ? in[ip++] & 0xff : 0;
170             int o0 = i0 >>> 2;
171             int o1 = ((i0 & 3) << 4) | (i1 >>> 4);
172             int o2 = ((i1 & 0xf) << 2) | (i2 >>> 6);
173             int o3 = i2 & 0x3F;
174             out[op++] = map1[o0];
175             out[op++] = map1[o1];
176             out[op] = op < oDataLen ? map1[o2] : '=';
177             op++;
178             out[op] = op < oDataLen ? map1[o3] : '=';
179             op++;
180         }
181         return out;
182     }
183 
184     /**
185      * Decodes a string from Base64 format. No blanks or line breaks are allowed
186      * within the Base64 encoded input data.
187      *
188      * @param s
189      *            A Base64 String to be decoded.
190      * @return A String containing the decoded data.
191      * @throws IllegalArgumentException
192      *             If the input is not valid Base64 encoded data.
193      */
194     public static String decodeString(String s) {
195         return new String(decode(s));
196     }
197 
198     /**
199      * Decodes a byte array from Base64 format and ignores line separators, tabs
200      * and blanks. CR, LF, Tab and Space characters are ignored in the input
201      * data. This method is compatible with
202      * <code>sun.misc.BASE64Decoder.decodeBuffer(String)</code>.
203      *
204      * @param s
205      *            A Base64 String to be decoded.
206      * @return An array containing the decoded data bytes.
207      * @throws IllegalArgumentException
208      *             If the input is not valid Base64 encoded data.
209      */
210     public static byte[] decodeLines(String s) {
211         char[] buf = new char[s.length()];
212         int p = 0;
213         for (int ip = 0; ip < s.length(); ip++) {
214             char c = s.charAt(ip);
215             if (c != ' ' && c != '\r' && c != '\n' && c != '\t')
216                 buf[p++] = c;
217         }
218         return decode(buf, 0, p);
219     }
220 
221     /**
222      * Decodes a byte array from Base64 format. No blanks or line breaks are
223      * allowed within the Base64 encoded input data.
224      *
225      * @param s
226      *            A Base64 String to be decoded.
227      * @return An array containing the decoded data bytes.
228      * @throws IllegalArgumentException
229      *             If the input is not valid Base64 encoded data.
230      */
231     public static byte[] decode(String s) {
232         return decode(s.toCharArray());
233     }
234 
235     /**
236      * Decodes a byte array from Base64 format. No blanks or line breaks are
237      * allowed within the Base64 encoded input data.
238      *
239      * @param in
240      *            A character array containing the Base64 encoded data.
241      * @return An array containing the decoded data bytes.
242      * @throws IllegalArgumentException
243      *             If the input is not valid Base64 encoded data.
244      */
245     public static byte[] decode(char[] in) {
246         return decode(in, 0, in.length);
247     }
248 
249     /**
250      * Decodes a byte array from Base64 format. No blanks or line breaks are
251      * allowed within the Base64 encoded input data.
252      *
253      * @param in
254      *            A character array containing the Base64 encoded data.
255      * @param iOff
256      *            Offset of the first character in <code>in</code> to be
257      *            processed.
258      * @param iLen
259      *            Number of characters to process in <code>in</code>, starting
260      *            at <code>iOff</code>.
261      * @return An array containing the decoded data bytes.
262      * @throws IllegalArgumentException
263      *             If the input is not valid Base64 encoded data.
264      */
265     public static byte[] decode(char[] in, int iOff, int iLen) {
266         if (iLen % 4 != 0)
267             throw new IllegalArgumentException(
268                     "Length of Base64 encoded input string is not a multiple of 4.");
269         while (iLen > 0 && in[iOff + iLen - 1] == '=')
270             iLen--;
271         int oLen = (iLen * 3) / 4;
272         byte[] out = new byte[oLen];
273         int ip = iOff;
274         int iEnd = iOff + iLen;
275         int op = 0;
276         while (ip < iEnd) {
277             int i0 = in[ip++];
278             int i1 = in[ip++];
279             int i2 = ip < iEnd ? in[ip++] : 'A';
280             int i3 = ip < iEnd ? in[ip++] : 'A';
281             if (i0 > 127 || i1 > 127 || i2 > 127 || i3 > 127)
282                 throw new IllegalArgumentException("Illegal character in Base64 encoded data.");
283             int b0 = map2[i0];
284             int b1 = map2[i1];
285             int b2 = map2[i2];
286             int b3 = map2[i3];
287             if (b0 < 0 || b1 < 0 || b2 < 0 || b3 < 0)
288                 throw new IllegalArgumentException("Illegal character in Base64 encoded data.");
289             int o0 = (b0 << 2) | (b1 >>> 4);
290             int o1 = ((b1 & 0xf) << 4) | (b2 >>> 2);
291             int o2 = ((b2 & 3) << 6) | b3;
292             out[op++] = (byte) o0;
293             if (op < oLen)
294                 out[op++] = (byte) o1;
295             if (op < oLen)
296                 out[op++] = (byte) o2;
297         }
298         return out;
299     }
300 
301     // Dummy constructor.
302     private Base64Coder() {
303     }
304 
305 } // end class Base64Coder
306