001/* CertPath.java -- a sequence of certificates 002 Copyright (C) 2002, 2005 Free Software Foundation, Inc. 003 004This file is part of GNU Classpath. 005 006GNU Classpath is free software; you can redistribute it and/or modify 007it under the terms of the GNU General Public License as published by 008the Free Software Foundation; either version 2, or (at your option) 009any later version. 010 011GNU Classpath is distributed in the hope that it will be useful, but 012WITHOUT ANY WARRANTY; without even the implied warranty of 013MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU 014General Public License for more details. 015 016You should have received a copy of the GNU General Public License 017along with GNU Classpath; see the file COPYING. If not, write to the 018Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 01902110-1301 USA. 020 021Linking this library statically or dynamically with other modules is 022making a combined work based on this library. Thus, the terms and 023conditions of the GNU General Public License cover the whole 024combination. 025 026As a special exception, the copyright holders of this library give you 027permission to link this library with independent modules to produce an 028executable, regardless of the license terms of these independent 029modules, and to copy and distribute the resulting executable under 030terms of your choice, provided that you also meet, for each linked 031independent module, the terms and conditions of the license of that 032module. An independent module is a module which is not derived from 033or based on this library. If you modify this library, you may extend 034this exception to your version of the library, but you are not 035obligated to do so. If you do not wish to do so, delete this 036exception statement from your version. */ 037 038package java.security.cert; 039 040import gnu.java.lang.CPStringBuilder; 041 042import java.io.ByteArrayInputStream; 043import java.io.NotSerializableException; 044import java.io.ObjectStreamException; 045import java.io.Serializable; 046import java.util.Iterator; 047import 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 */ 063public 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