001 /* Certificate.java --- Certificate class
002 Copyright (C) 1999, 2003, 2004 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
039 package java.security.cert;
040
041 import java.io.ByteArrayInputStream;
042 import java.io.InvalidObjectException;
043 import java.io.ObjectStreamException;
044 import java.io.Serializable;
045 import java.security.InvalidKeyException;
046 import java.security.NoSuchAlgorithmException;
047 import java.security.NoSuchProviderException;
048 import java.security.PublicKey;
049 import java.security.SignatureException;
050
051 /**
052 * The Certificate class is an abstract class used to manage
053 * identity certificates. An identity certificate is a
054 * combination of a principal and a public key which is
055 * certified by another principal. This is the puprose of
056 * Certificate Authorities (CA).
057 *
058 * <p>This class is used to manage different types of certificates
059 * but have important common puposes. Different types of
060 * certificates like X.509 and OpenPGP share general certificate
061 * functions (like encoding and verifying) and information like
062 * public keys.
063 *
064 * <p>X.509, OpenPGP, and SDSI can be implemented by subclassing this
065 * class even though they differ in storage methods and information
066 * stored.
067 *
068 * @see CertificateFactory
069 * @see X509Certificate
070 * @since JDK 1.2
071 * @author Mark Benvenuto
072 * @author Casey Marshall
073 */
074 public abstract class Certificate implements Serializable
075 {
076 private static final long serialVersionUID = -3585440601605666277L;
077
078 private String type;
079
080 /**
081 Constructs a new certificate of the specified type. An example
082 is "X.509".
083
084 @param type a valid standard name for a certificate.
085 */
086 protected Certificate(String type)
087 {
088 this.type = type;
089 }
090
091 /**
092 Returns the Certificate type.
093
094 @return a string representing the Certificate type
095 */
096 public final String getType()
097 {
098 return type;
099 }
100
101 /**
102 Compares this Certificate to other. It checks if the
103 object if instanceOf Certificate and then checks if
104 the encoded form matches.
105
106 @param other An Object to test for equality
107
108 @return true if equal, false otherwise
109 */
110 public boolean equals(Object other)
111 {
112 if( other instanceof Certificate ) {
113 try {
114 Certificate x = (Certificate) other;
115 if( getEncoded().length != x.getEncoded().length )
116 return false;
117
118 byte[] b1 = getEncoded();
119 byte[] b2 = x.getEncoded();
120
121 for( int i = 0; i < b1.length; i++ )
122 if( b1[i] != b2[i] )
123 return false;
124
125 } catch( CertificateEncodingException cee ) {
126 return false;
127 }
128 return true;
129 }
130 return false;
131 }
132
133 /**
134 Returns a hash code for this Certificate in its encoded
135 form.
136
137 @return A hash code of this class
138 */
139 public int hashCode()
140 {
141 return super.hashCode();
142 }
143
144 /**
145 Gets the DER ASN.1 encoded format for this Certificate.
146 It assumes each certificate has only one encoding format.
147 Ex: X.509 is encoded as ASN.1 DER
148
149 @return byte array containg encoded form
150
151 @throws CertificateEncodingException if an error occurs
152 */
153 public abstract byte[] getEncoded() throws CertificateEncodingException;
154
155 /**
156 Verifies that this Certificate was properly signed with the
157 PublicKey that corresponds to its private key.
158
159 @param key PublicKey to verify with
160
161 @throws CertificateException encoding error
162 @throws NoSuchAlgorithmException unsupported algorithm
163 @throws InvalidKeyException incorrect key
164 @throws NoSuchProviderException no provider
165 @throws SignatureException signature error
166 */
167 public abstract void verify(PublicKey key)
168 throws CertificateException,
169 NoSuchAlgorithmException,
170 InvalidKeyException,
171 NoSuchProviderException,
172 SignatureException;
173
174 /**
175 Verifies that this Certificate was properly signed with the
176 PublicKey that corresponds to its private key and uses
177 the signature engine provided by the provider.
178
179 @param key PublicKey to verify with
180 @param sigProvider Provider to use for signature algorithm
181
182 @throws CertificateException encoding error
183 @throws NoSuchAlgorithmException unsupported algorithm
184 @throws InvalidKeyException incorrect key
185 @throws NoSuchProviderException incorrect provider
186 @throws SignatureException signature error
187 */
188 public abstract void verify(PublicKey key,
189 String sigProvider)
190 throws CertificateException,
191 NoSuchAlgorithmException,
192 InvalidKeyException,
193 NoSuchProviderException,
194 SignatureException;
195
196 /**
197 Returns a string representing the Certificate.
198
199 @return a string representing the Certificate.
200 */
201 public abstract String toString();
202
203
204 /**
205 Returns the public key stored in the Certificate.
206
207 @return The public key
208 */
209 public abstract PublicKey getPublicKey();
210
211 // Protected methods.
212 // ------------------------------------------------------------------------
213
214 /**
215 * Returns a replacement for this certificate to be serialized. This
216 * method returns the equivalent to the following for this class:
217 *
218 * <blockquote>
219 * <pre>new CertificateRep(getType(), getEncoded());</pre>
220 * </blockquote>
221 *
222 * <p>This thusly replaces the certificate with its name and its
223 * encoded form, which can be deserialized later with the {@link
224 * CertificateFactory} implementation for this certificate's type.
225 *
226 * @return The replacement object to be serialized.
227 * @throws ObjectStreamException If the replacement could not be
228 * created.
229 */
230 protected Object writeReplace() throws ObjectStreamException
231 {
232 try
233 {
234 return new CertificateRep(getType(), getEncoded());
235 }
236 catch (CertificateEncodingException cee)
237 {
238 throw new InvalidObjectException(cee.toString());
239 }
240 }
241
242 // Inner class.
243 // ------------------------------------------------------------------------
244
245 /**
246 Certificate.CertificateRep is an inner class used to provide an alternate
247 storage mechanism for serialized Certificates.
248 */
249 protected static class CertificateRep implements java.io.Serializable
250 {
251
252 /** From JDK1.4. */
253 private static final long serialVersionUID = -8563758940495660020L;
254
255 /** The certificate type, e.g. "X.509". */
256 private String type;
257
258 /** The encoded certificate data. */
259 private byte[] data;
260
261 /**
262 * Create an alternative representation of this certificate. The
263 * <code>(type, data)</code> pair is typically the certificate's
264 * type as returned by {@link Certificate#getType()} (i.e. the
265 * canonical name of the certificate type) and the encoded form as
266 * returned by {@link Certificate#getEncoded()}.
267 *
268 * <p>For example, X.509 certificates would create an instance of
269 * this class with the parameters "X.509" and the ASN.1
270 * representation of the certificate, encoded as DER bytes.
271 *
272 * @param type The certificate type.
273 * @param data The encoded certificate data.
274 */
275 protected CertificateRep(String type, byte[] data)
276 {
277 this.type = type;
278 this.data = data;
279 }
280
281 /**
282 * Deserialize this certificate replacement into the appropriate
283 * certificate object. That is, this method attempts to create a
284 * {@link CertificateFactory} for this certificate's type, then
285 * attempts to parse the encoded data with that factory, returning
286 * the resulting certificate.
287 *
288 * @return The deserialized certificate.
289 * @throws ObjectStreamException If there is no appropriate
290 * certificate factory for the given type, or if the encoded form
291 * cannot be parsed.
292 */
293 protected Object readResolve() throws ObjectStreamException
294 {
295 try
296 {
297 CertificateFactory fact = CertificateFactory.getInstance(type);
298 return fact.generateCertificate(new ByteArrayInputStream(data));
299 }
300 catch (Exception e)
301 {
302 throw new InvalidObjectException(e.toString());
303 }
304 }
305 }
306 }