1 /* CertPath.java -- a sequence of certificates 2 Copyright (C) 2002, 2005 Free Software Foundation, Inc. 3 4 This file is part of GNU Classpath. 5 6 GNU Classpath is free software; you can redistribute it and/or modify 7 it under the terms of the GNU General Public License as published by 8 the Free Software Foundation; either version 2, or (at your option) 9 any later version. 10 11 GNU Classpath is distributed in the hope that it will be useful, but 12 WITHOUT ANY WARRANTY; without even the implied warranty of 13 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU 14 General Public License for more details. 15 16 You should have received a copy of the GNU General Public License 17 along with GNU Classpath; see the file COPYING. If not, write to the 18 Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 19 02110-1301 USA. 20 21 Linking this library statically or dynamically with other modules is 22 making a combined work based on this library. Thus, the terms and 23 conditions of the GNU General Public License cover the whole 24 combination. 25 26 As a special exception, the copyright holders of this library give you 27 permission to link this library with independent modules to produce an 28 executable, regardless of the license terms of these independent 29 modules, and to copy and distribute the resulting executable under 30 terms of your choice, provided that you also meet, for each linked 31 independent module, the terms and conditions of the license of that 32 module. An independent module is a module which is not derived from 33 or based on this library. If you modify this library, you may extend 34 this exception to your version of the library, but you are not 35 obligated to do so. If you do not wish to do so, delete this 36 exception statement from your version. */ 37 38 package java.security.cert; 39 40 import java.io.ByteArrayInputStream; 41 import java.io.NotSerializableException; 42 import java.io.ObjectStreamException; 43 import java.io.Serializable; 44 import java.util.Iterator; 45 import java.util.List; 46 47 /** 48 * This class represents an immutable sequence, or path, of security 49 * certificates. The path type must match the type of each certificate in the 50 * path, or in other words, for all instances of cert in a certpath object, 51 * <code>cert.getType().equals(certpath.getType())</code> will return true. 52 * 53 * <p>Since this class is immutable, it is thread-safe. During serialization, 54 * the path is consolidated into a {@link CertPathRep}, which preserves the 55 * data regardless of the underlying implementation of the path. 56 * 57 * @author Eric Blake (ebb9@email.byu.edu) 58 * @since 1.4 59 * @status updated to 1.4 60 */ 61 public abstract class CertPath implements Serializable 62 { 63 /** 64 * The serialized representation of a path. 65 * 66 * @author Eric Blake (ebb9@email.byu.edu) 67 */ 68 protected static class CertPathRep implements Serializable 69 { 70 /** 71 * Compatible with JDK 1.4+. 72 */ 73 private static final long serialVersionUID = 3015633072427920915L; 74 75 /** 76 * The certificate type. 77 * 78 * @serial the type of the certificate path 79 */ 80 private final String type; 81 82 /** 83 * The encoded form of the path. 84 * 85 * @serial the encoded form 86 */ 87 private final byte[] data; 88 89 /** 90 * Create the new serial representation. 91 * 92 * @param type the path type 93 * @param data the encoded path data 94 */ CertPathRep(String type, byte[] data)95 protected CertPathRep(String type, byte[] data) 96 { 97 this.type = type; 98 this.data = data; 99 } 100 101 /** 102 * Decode the data into an actual {@link CertPath} upon deserialization. 103 * 104 * @return the replacement object 105 * @throws ObjectStreamException if replacement fails 106 */ readResolve()107 protected Object readResolve() throws ObjectStreamException 108 { 109 try 110 { 111 return CertificateFactory.getInstance(type) 112 .generateCertPath(new ByteArrayInputStream(data)); 113 } 114 catch (CertificateException e) 115 { 116 throw (ObjectStreamException) 117 new NotSerializableException("java.security.cert.CertPath: " 118 + type).initCause(e); 119 } 120 } 121 } // class CertPathRep 122 123 /** 124 * Compatible with JDK 1.4+. 125 */ 126 private static final long serialVersionUID = 6068470306649138683L; 127 128 /** 129 * The path type. 130 * 131 * @serial the type of all certificates in this path 132 */ 133 private final String type; 134 135 /** 136 * Create a certificate path with the given type. Most code should use 137 * {@link CertificateFactory} to create CertPaths. 138 * 139 * @param type the type of the path 140 */ CertPath(String type)141 protected CertPath(String type) 142 { 143 this.type = type; 144 } 145 146 /** 147 * Get the (non-null) type of all certificates in the path. 148 * 149 * @return the path certificate type 150 */ getType()151 public String getType() 152 { 153 return type; 154 } 155 156 /** 157 * Get an immutable iterator over the path encodings (all String names), 158 * starting with the default encoding. The iterator will throw an 159 * <code>UnsupportedOperationException</code> if an attempt is made to 160 * remove items from the list. 161 * 162 * @return the iterator of supported encodings in the path 163 */ getEncodings()164 public abstract Iterator getEncodings(); 165 166 /** 167 * Compares this path to another for semantic equality. To be equal, both 168 * must be instances of CertPath, with the same type, and identical 169 * certificate lists. Overriding classes must not change this behavior. 170 * 171 * @param o the object to compare to 172 * @return true if the two are equal 173 */ equals(Object o)174 public boolean equals(Object o) 175 { 176 if (! (o instanceof CertPath)) 177 return false; 178 CertPath cp = (CertPath) o; 179 return type.equals(cp.type) 180 && getCertificates().equals(cp.getCertificates()); 181 } 182 183 /** 184 * Returns the hashcode of this certificate path. This is defined as:<br> 185 * <code>31 * getType().hashCode() + getCertificates().hashCode()</code>. 186 * 187 * @return the hashcode 188 */ hashCode()189 public int hashCode() 190 { 191 return 31 * type.hashCode() + getCertificates().hashCode(); 192 } 193 toString()194 public String toString() 195 { 196 List l = getCertificates(); 197 int size = l.size(); 198 int i = 0; 199 StringBuffer result = new StringBuffer(type); 200 result.append(" Cert Path: length = ").append(size).append(".\n[\n"); 201 while (--size >= 0) 202 result.append(l.get(i++)).append('\n'); 203 return result.append("\n]").toString(); 204 } 205 206 /** 207 * Returns the encoded form of this path, via the default encoding. 208 * 209 * @return the encoded form 210 * @throws CertificateEncodingException if encoding fails 211 */ getEncoded()212 public abstract byte[] getEncoded() throws CertificateEncodingException; 213 214 /** 215 * Returns the encoded form of this path, via the specified encoding. 216 * 217 * @param encoding the encoding to use 218 * @return the encoded form 219 * @throws CertificateEncodingException if encoding fails or does not exist 220 */ getEncoded(String encoding)221 public abstract byte[] getEncoded(String encoding) 222 throws CertificateEncodingException; 223 224 /** 225 * Returns the immutable, thread-safe list of certificates in this path. 226 * 227 * @return the list of certificates, non-null but possibly empty 228 */ getCertificates()229 public abstract List getCertificates(); 230 231 /** 232 * Serializes the path in its encoded form, to ensure reserialization with 233 * the appropriate factory object without worrying about list implementation. 234 * The result will always be an instance of {@link CertPathRep}. 235 * 236 * @return the replacement object 237 * @throws ObjectStreamException if the replacement creation fails 238 */ writeReplace()239 protected Object writeReplace() throws ObjectStreamException 240 { 241 try 242 { 243 return new CertPathRep(type, getEncoded()); 244 } 245 catch (CertificateEncodingException e) 246 { 247 throw (ObjectStreamException) 248 new NotSerializableException("java.security.cert.CertPath: " 249 + type).initCause(e); 250 } 251 } 252 } // class CertPath 253