001 /* CertPath.java -- a sequence of certificates
002 Copyright (C) 2002, 2005 Free Software Foundation, Inc.
003
004 This file is part of GNU Classpath.
005
006 GNU Classpath is free software; you can redistribute it and/or modify
007 it under the terms of the GNU General Public License as published by
008 the Free Software Foundation; either version 2, or (at your option)
009 any later version.
010
011 GNU Classpath is distributed in the hope that it will be useful, but
012 WITHOUT ANY WARRANTY; without even the implied warranty of
013 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
014 General Public License for more details.
015
016 You should have received a copy of the GNU General Public License
017 along with GNU Classpath; see the file COPYING. If not, write to the
018 Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
019 02110-1301 USA.
020
021 Linking this library statically or dynamically with other modules is
022 making a combined work based on this library. Thus, the terms and
023 conditions of the GNU General Public License cover the whole
024 combination.
025
026 As a special exception, the copyright holders of this library give you
027 permission to link this library with independent modules to produce an
028 executable, regardless of the license terms of these independent
029 modules, and to copy and distribute the resulting executable under
030 terms of your choice, provided that you also meet, for each linked
031 independent module, the terms and conditions of the license of that
032 module. An independent module is a module which is not derived from
033 or based on this library. If you modify this library, you may extend
034 this exception to your version of the library, but you are not
035 obligated to do so. If you do not wish to do so, delete this
036 exception statement from your version. */
037
038 package java.security.cert;
039
040 import gnu.java.lang.CPStringBuilder;
041
042 import java.io.ByteArrayInputStream;
043 import java.io.NotSerializableException;
044 import java.io.ObjectStreamException;
045 import java.io.Serializable;
046 import java.util.Iterator;
047 import java.util.List;
048
049 /**
050 * This class represents an immutable sequence, or path, of security
051 * certificates. The path type must match the type of each certificate in the
052 * path, or in other words, for all instances of cert in a certpath object,
053 * <code>cert.getType().equals(certpath.getType())</code> will return true.
054 *
055 * <p>Since this class is immutable, it is thread-safe. During serialization,
056 * the path is consolidated into a {@link CertPathRep}, which preserves the
057 * data regardless of the underlying implementation of the path.
058 *
059 * @author Eric Blake (ebb9@email.byu.edu)
060 * @since 1.4
061 * @status updated to 1.4
062 */
063 public abstract class CertPath implements Serializable
064 {
065 /**
066 * The serialized representation of a path.
067 *
068 * @author Eric Blake (ebb9@email.byu.edu)
069 */
070 protected static class CertPathRep implements Serializable
071 {
072 /**
073 * Compatible with JDK 1.4+.
074 */
075 private static final long serialVersionUID = 3015633072427920915L;
076
077 /**
078 * The certificate type.
079 *
080 * @serial the type of the certificate path
081 */
082 private final String type;
083
084 /**
085 * The encoded form of the path.
086 *
087 * @serial the encoded form
088 */
089 private final byte[] data;
090
091 /**
092 * Create the new serial representation.
093 *
094 * @param type the path type
095 * @param data the encoded path data
096 */
097 protected CertPathRep(String type, byte[] data)
098 {
099 this.type = type;
100 this.data = data;
101 }
102
103 /**
104 * Decode the data into an actual {@link CertPath} upon deserialization.
105 *
106 * @return the replacement object
107 * @throws ObjectStreamException if replacement fails
108 */
109 protected Object readResolve() throws ObjectStreamException
110 {
111 try
112 {
113 return CertificateFactory.getInstance(type)
114 .generateCertPath(new ByteArrayInputStream(data));
115 }
116 catch (CertificateException e)
117 {
118 throw (ObjectStreamException)
119 new NotSerializableException("java.security.cert.CertPath: "
120 + type).initCause(e);
121 }
122 }
123 } // class CertPathRep
124
125 /**
126 * Compatible with JDK 1.4+.
127 */
128 private static final long serialVersionUID = 6068470306649138683L;
129
130 /**
131 * The path type.
132 *
133 * @serial the type of all certificates in this path
134 */
135 private final String type;
136
137 /**
138 * Create a certificate path with the given type. Most code should use
139 * {@link CertificateFactory} to create CertPaths.
140 *
141 * @param type the type of the path
142 */
143 protected CertPath(String type)
144 {
145 this.type = type;
146 }
147
148 /**
149 * Get the (non-null) type of all certificates in the path.
150 *
151 * @return the path certificate type
152 */
153 public String getType()
154 {
155 return type;
156 }
157
158 /**
159 * Get an immutable iterator over the path encodings (all String names),
160 * starting with the default encoding. The iterator will throw an
161 * <code>UnsupportedOperationException</code> if an attempt is made to
162 * remove items from the list.
163 *
164 * @return the iterator of supported encodings in the path
165 */
166 public abstract Iterator<String> getEncodings();
167
168 /**
169 * Compares this path to another for semantic equality. To be equal, both
170 * must be instances of CertPath, with the same type, and identical
171 * certificate lists. Overriding classes must not change this behavior.
172 *
173 * @param o the object to compare to
174 * @return true if the two are equal
175 */
176 public boolean equals(Object o)
177 {
178 if (! (o instanceof CertPath))
179 return false;
180 CertPath cp = (CertPath) o;
181 return type.equals(cp.type)
182 && getCertificates().equals(cp.getCertificates());
183 }
184
185 /**
186 * Returns the hashcode of this certificate path. This is defined as:<br>
187 * <code>31 * getType().hashCode() + getCertificates().hashCode()</code>.
188 *
189 * @return the hashcode
190 */
191 public int hashCode()
192 {
193 return 31 * type.hashCode() + getCertificates().hashCode();
194 }
195
196 public String toString()
197 {
198 List l = getCertificates();
199 int size = l.size();
200 int i = 0;
201 CPStringBuilder result = new CPStringBuilder(type);
202 result.append(" Cert Path: length = ").append(size).append(".\n[\n");
203 while (--size >= 0)
204 result.append(l.get(i++)).append('\n');
205 return result.append("\n]").toString();
206 }
207
208 /**
209 * Returns the encoded form of this path, via the default encoding.
210 *
211 * @return the encoded form
212 * @throws CertificateEncodingException if encoding fails
213 */
214 public abstract byte[] getEncoded() throws CertificateEncodingException;
215
216 /**
217 * Returns the encoded form of this path, via the specified encoding.
218 *
219 * @param encoding the encoding to use
220 * @return the encoded form
221 * @throws CertificateEncodingException if encoding fails or does not exist
222 */
223 public abstract byte[] getEncoded(String encoding)
224 throws CertificateEncodingException;
225
226 /**
227 * Returns the immutable, thread-safe list of certificates in this path.
228 *
229 * @return the list of certificates, non-null but possibly empty
230 */
231 public abstract List<? extends Certificate> getCertificates();
232
233 /**
234 * Serializes the path in its encoded form, to ensure reserialization with
235 * the appropriate factory object without worrying about list implementation.
236 * The result will always be an instance of {@link CertPathRep}.
237 *
238 * @return the replacement object
239 * @throws ObjectStreamException if the replacement creation fails
240 */
241 protected Object writeReplace() throws ObjectStreamException
242 {
243 try
244 {
245 return new CertPathRep(type, getEncoded());
246 }
247 catch (CertificateEncodingException e)
248 {
249 throw (ObjectStreamException)
250 new NotSerializableException("java.security.cert.CertPath: "
251 + type).initCause(e);
252 }
253 }
254 } // class CertPath