1 /*
2 * Licensed to the Apache Software Foundation (ASF) under one or more
3 * contributor license agreements. See the NOTICE file distributed with
4 * this work for additional information regarding copyright ownership.
5 * The ASF licenses this file to You under the Apache License, Version 2.0
6 * (the "License"); you may not use this file except in compliance with
7 * the License. You may obtain a copy of the License at
8 *
9 * http://www.apache.org/licenses/LICENSE-2.0
10 *
11 * Unless required by applicable law or agreed to in writing, software
12 * distributed under the License is distributed on an "AS IS" BASIS,
13 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
14 * See the License for the specific language governing permissions and
15 * limitations under the License.
16 */
17
18 package edu.internet2.middleware.grouperClientExt.org.apache.commons.codec.net;
19
20 import java.io.UnsupportedEncodingException;
21 import java.nio.charset.Charset;
22 import java.nio.charset.StandardCharsets;
23
24 import edu.internet2.middleware.grouperClientExt.org.apache.commons.codec.CodecPolicy;
25 import edu.internet2.middleware.grouperClientExt.org.apache.commons.codec.DecoderException;
26 import edu.internet2.middleware.grouperClientExt.org.apache.commons.codec.EncoderException;
27 import edu.internet2.middleware.grouperClientExt.org.apache.commons.codec.StringDecoder;
28 import edu.internet2.middleware.grouperClientExt.org.apache.commons.codec.StringEncoder;
29 import edu.internet2.middleware.grouperClientExt.org.apache.commons.codec.binary.Base64;
30 import edu.internet2.middleware.grouperClientExt.org.apache.commons.codec.binary.BaseNCodec;
31
32 /**
33 * Identical to the Base64 encoding defined by <a href="http://www.ietf.org/rfc/rfc1521.txt">RFC 1521</a>
34 * and allows a character set to be specified.
35 * <p>
36 * <a href="http://www.ietf.org/rfc/rfc1522.txt">RFC 1522</a> describes techniques to allow the encoding of non-ASCII
37 * text in various portions of a RFC 822 [2] message header, in a manner which is unlikely to confuse existing message
38 * handling software.
39 * </p>
40 * <p>
41 * This class is immutable and thread-safe.
42 * </p>
43 *
44 * @see <a href="http://www.ietf.org/rfc/rfc1522.txt">MIME (Multipurpose Internet Mail Extensions) Part Two: Message
45 * Header Extensions for Non-ASCII Text</a>
46 *
47 * @since 1.3
48 */
49 public class BCodec extends RFC1522Codec implements StringEncoder, StringDecoder {
50
51 /**
52 * The default decoding policy.
53 */
54 private static final CodecPolicy DECODING_POLICY_DEFAULT = CodecPolicy.LENIENT;
55
56 /**
57 * The default Charset used for string decoding and encoding.
58 */
59 private final Charset charset;
60
61 /**
62 * If true then decoding should throw an exception for impossible combinations of bits at the
63 * end of the byte input. The default is to decode as much of them as possible.
64 */
65 private final CodecPolicy decodingPolicy;
66
67 /**
68 * Default constructor.
69 */
70 public BCodec() {
71 this(StandardCharsets.UTF_8);
72 }
73
74 /**
75 * Constructor which allows for the selection of a default Charset
76 *
77 * @param charset
78 * the default string Charset to use.
79 *
80 * @see <a href="http://download.oracle.com/javase/7/docs/api/java/nio/charset/Charset.html">Standard charsets</a>
81 * @since 1.7
82 */
83 public BCodec(final Charset charset) {
84 this(charset, DECODING_POLICY_DEFAULT);
85 }
86
87 /**
88 * Constructor which allows for the selection of a default Charset.
89 *
90 * @param charset
91 * the default string Charset to use.
92 * @param decodingPolicy The decoding policy.
93 *
94 * @see <a href="http://download.oracle.com/javase/7/docs/api/java/nio/charset/Charset.html">Standard charsets</a>
95 * @since 1.15
96 */
97 public BCodec(final Charset charset, final CodecPolicy decodingPolicy) {
98 this.charset = charset;
99 this.decodingPolicy = decodingPolicy;
100 }
101
102 /**
103 * Constructor which allows for the selection of a default Charset
104 *
105 * @param charsetName
106 * the default Charset to use.
107 * @throws java.nio.charset.UnsupportedCharsetException
108 * If the named Charset is unavailable
109 * @since 1.7 throws UnsupportedCharsetException if the named Charset is unavailable
110 * @see <a href="http://download.oracle.com/javase/7/docs/api/java/nio/charset/Charset.html">Standard charsets</a>
111 */
112 public BCodec(final String charsetName) {
113 this(Charset.forName(charsetName));
114 }
115
116 /**
117 * Returns true if decoding behavior is strict. Decoding will raise a
118 * {@link DecoderException} if trailing bits are not part of a valid Base64 encoding.
119 *
120 * <p>The default is false for lenient encoding. Decoding will compose trailing bits
121 * into 8-bit bytes and discard the remainder.
122 *
123 * @return true if using strict decoding
124 * @since 1.15
125 */
126 public boolean isStrictDecoding() {
127 return decodingPolicy == CodecPolicy.STRICT;
128 }
129
130 @Override
131 protected String getEncoding() {
132 return "B";
133 }
134
135 @Override
136 protected byte[] doEncoding(final byte[] bytes) {
137 if (bytes == null) {
138 return null;
139 }
140 return Base64.encodeBase64(bytes);
141 }
142
143 @Override
144 protected byte[] doDecoding(final byte[] bytes) {
145 if (bytes == null) {
146 return null;
147 }
148 return new Base64(0, BaseNCodec.getChunkSeparator(), false, decodingPolicy).decode(bytes);
149 }
150
151 /**
152 * Encodes a string into its Base64 form using the specified Charset. Unsafe characters are escaped.
153 *
154 * @param strSource
155 * string to convert to Base64 form
156 * @param sourceCharset
157 * the Charset for {@code value}
158 * @return Base64 string
159 * @throws EncoderException
160 * thrown if a failure condition is encountered during the encoding process.
161 * @since 1.7
162 */
163 public String encode(final String strSource, final Charset sourceCharset) throws EncoderException {
164 if (strSource == null) {
165 return null;
166 }
167 return encodeText(strSource, sourceCharset);
168 }
169
170 /**
171 * Encodes a string into its Base64 form using the specified Charset. Unsafe characters are escaped.
172 *
173 * @param strSource
174 * string to convert to Base64 form
175 * @param sourceCharset
176 * the Charset for {@code value}
177 * @return Base64 string
178 * @throws EncoderException
179 * thrown if a failure condition is encountered during the encoding process.
180 */
181 public String encode(final String strSource, final String sourceCharset) throws EncoderException {
182 if (strSource == null) {
183 return null;
184 }
185 try {
186 return this.encodeText(strSource, sourceCharset);
187 } catch (final UnsupportedEncodingException e) {
188 throw new EncoderException(e.getMessage(), e);
189 }
190 }
191
192 /**
193 * Encodes a string into its Base64 form using the default Charset. Unsafe characters are escaped.
194 *
195 * @param strSource
196 * string to convert to Base64 form
197 * @return Base64 string
198 * @throws EncoderException
199 * thrown if a failure condition is encountered during the encoding process.
200 */
201 @Override
202 public String encode(final String strSource) throws EncoderException {
203 if (strSource == null) {
204 return null;
205 }
206 return encode(strSource, this.getCharset());
207 }
208
209 /**
210 * Decodes a Base64 string into its original form. Escaped characters are converted back to their original
211 * representation.
212 *
213 * @param value
214 * Base64 string to convert into its original form
215 * @return original string
216 * @throws DecoderException
217 * A decoder exception is thrown if a failure condition is encountered during the decode process.
218 */
219 @Override
220 public String decode(final String value) throws DecoderException {
221 if (value == null) {
222 return null;
223 }
224 try {
225 return this.decodeText(value);
226 } catch (final UnsupportedEncodingException | IllegalArgumentException e) {
227 throw new DecoderException(e.getMessage(), e);
228 }
229 }
230
231 /**
232 * Encodes an object into its Base64 form using the default Charset. Unsafe characters are escaped.
233 *
234 * @param value
235 * object to convert to Base64 form
236 * @return Base64 object
237 * @throws EncoderException
238 * thrown if a failure condition is encountered during the encoding process.
239 */
240 @Override
241 public Object encode(final Object value) throws EncoderException {
242 if (value == null) {
243 return null;
244 } else if (value instanceof String) {
245 return encode((String) value);
246 } else {
247 throw new EncoderException("Objects of type " +
248 value.getClass().getName() +
249 " cannot be encoded using BCodec");
250 }
251 }
252
253 /**
254 * Decodes a Base64 object into its original form. Escaped characters are converted back to their original
255 * representation.
256 *
257 * @param value
258 * Base64 object to convert into its original form
259 * @return original object
260 * @throws DecoderException
261 * Thrown if the argument is not a {@code String}. Thrown if a failure condition is encountered
262 * during the decode process.
263 */
264 @Override
265 public Object decode(final Object value) throws DecoderException {
266 if (value == null) {
267 return null;
268 } else if (value instanceof String) {
269 return decode((String) value);
270 } else {
271 throw new DecoderException("Objects of type " +
272 value.getClass().getName() +
273 " cannot be decoded using BCodec");
274 }
275 }
276
277 /**
278 * Gets the default Charset name used for string decoding and encoding.
279 *
280 * @return the default Charset name
281 * @since 1.7
282 */
283 public Charset getCharset() {
284 return this.charset;
285 }
286
287 /**
288 * Gets the default Charset name used for string decoding and encoding.
289 *
290 * @return the default Charset name
291 */
292 public String getDefaultCharset() {
293 return this.charset.name();
294 }
295 }