001 /* CodeSource.java -- Code location and certifcates
002 Copyright (C) 1998, 2002, 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;
040
041 import gnu.java.lang.CPStringBuilder;
042
043 import java.io.ByteArrayInputStream;
044 import java.io.IOException;
045 import java.io.ObjectInputStream;
046 import java.io.ObjectOutputStream;
047 import java.io.Serializable;
048 import java.net.SocketPermission;
049 import java.net.URL;
050 // Note that this overrides Certificate in this package.
051 import java.security.cert.Certificate;
052 import java.security.cert.CertificateEncodingException;
053 import java.security.cert.CertificateException;
054 import java.security.cert.CertificateFactory;
055 import java.util.Arrays;
056 import java.util.HashSet;
057 import java.util.Iterator;
058
059 /**
060 * This class represents a location from which code is loaded (as
061 * represented by a URL), and the list of certificates that are used to
062 * check the signatures of signed code loaded from this source.
063 *
064 * @author Aaron M. Renn (arenn@urbanophile.com)
065 * @author Eric Blake (ebb9@email.byu.edu)
066 * @since 1.1
067 * @status updated to 1.4
068 */
069 public class CodeSource implements Serializable
070 {
071 /**
072 * Compatible with JDK 1.1+.
073 */
074 private static final long serialVersionUID = 4977541819976013951L;
075
076 /**
077 * This is the URL that represents the code base from which code will
078 * be loaded.
079 *
080 * @serial the code location
081 */
082 private final URL location;
083
084 /** The set of certificates for this code base. */
085 private transient HashSet certs;
086
087 /**
088 * This creates a new instance of <code>CodeSource</code> that loads code
089 * from the specified URL location and which uses the specified certificates
090 * for verifying signatures.
091 *
092 * @param location the location from which code will be loaded
093 * @param certs the list of certificates
094 */
095 public CodeSource(URL location, Certificate[] certs)
096 {
097 this.location = location;
098 if (certs != null)
099 this.certs = new HashSet(Arrays.asList(certs));
100 }
101
102 /**
103 * This method returns a hash value for this object.
104 *
105 * @return a hash value for this object
106 */
107 public int hashCode()
108 {
109 return (location == null ? 0 : location.hashCode())
110 ^ (certs == null ? 0 : certs.hashCode());
111 }
112
113 /**
114 * This method tests the specified <code>Object</code> for equality with
115 * this object. This will be true if and only if the locations are equal
116 * and the certificate sets are identical (ignoring order).
117 *
118 * @param obj the <code>Object</code> to test against
119 * @return true if the specified object is equal to this one
120 */
121 public boolean equals(Object obj)
122 {
123 if (! (obj instanceof CodeSource))
124 return false;
125 CodeSource cs = (CodeSource) obj;
126 return (certs == null ? cs.certs == null : certs.equals(cs.certs))
127 && (location == null ? cs.location == null
128 : location.equals(cs.location));
129 }
130
131 /**
132 * This method returns the URL specifying the location from which code
133 * will be loaded under this <code>CodeSource</code>.
134 *
135 * @return the code location for this <code>CodeSource</code>
136 */
137 public final URL getLocation()
138 {
139 return location;
140 }
141
142 /**
143 * This method returns the list of digital certificates that can be used
144 * to verify the signatures of code loaded under this
145 * <code>CodeSource</code>.
146 *
147 * @return the certifcate list for this <code>CodeSource</code>
148 */
149 public final Certificate[] getCertificates()
150 {
151 if (certs == null)
152 return null;
153 Certificate[] c = new Certificate[certs.size()];
154 certs.toArray(c);
155 return c;
156 }
157
158 /**
159 * This method tests to see if a specified <code>CodeSource</code> is
160 * implied by this object. Effectively, to meet this test, the specified
161 * object must have all the certifcates this object has (but may have more),
162 * and must have a location that is a subset of this object's. In order
163 * for this object to imply the specified object, the following must be
164 * true:
165 *
166 * <ol>
167 * <li><em>codesource</em> must not be <code>null</code>.</li>
168 * <li>If <em>codesource</em> has a certificate list, all of it's
169 * certificates must be present in the certificate list of this
170 * code source.</li>
171 * <li>If this object does not have a <code>null</code> location, then
172 * the following addtional tests must be passed.
173 *
174 * <ol>
175 * <li><em>codesource</em> must not have a <code>null</code>
176 * location.</li>
177 * <li><em>codesource</em>'s location must be equal to this object's
178 * location, or
179 * <ul>
180 * <li><em>codesource</em>'s location protocol, port, and ref (aka,
181 * anchor) must equal this objects</li>
182 * <li><em>codesource</em>'s location host must imply this object's
183 * location host, as determined by contructing
184 * <code>SocketPermission</code> objects from each with no
185 * action list and using that classes's <code>implies</code>
186 * method</li>
187 * <li>If this object's location file ends with a '/', then the
188 * specified object's location file must start with this
189 * object's location file. Otherwise, the specified object's
190 * location file must start with this object's location file
191 * with the '/' character appended to it.</li>
192 * </ul></li>
193 * </ol></li>
194 * </ol>
195 *
196 * <p>For example, each of these locations imply the location
197 * "http://java.sun.com/classes/foo.jar":</p>
198 *
199 * <pre>
200 * http:
201 * http://*.sun.com/classes/*
202 * http://java.sun.com/classes/-
203 * http://java.sun.com/classes/foo.jar
204 * </pre>
205 *
206 * <p>Note that the code source with null location and null certificates implies
207 * all other code sources.</p>
208 *
209 * @param cs the <code>CodeSource</code> to test against this object
210 * @return true if this specified <code>CodeSource</code> is implied
211 */
212 public boolean implies(CodeSource cs)
213 {
214 if (cs == null)
215 return false;
216 // First check the certificate list.
217 if (certs != null && (cs.certs == null || ! certs.containsAll(cs.certs)))
218 return false;
219 // Next check the location.
220 if (location == null)
221 return true;
222 if (cs.location == null
223 || ! location.getProtocol().equals(cs.location.getProtocol())
224 || (location.getPort() != -1
225 && location.getPort() != cs.location.getPort())
226 || (location.getRef() != null
227 && ! location.getRef().equals(cs.location.getRef())))
228 return false;
229 if (location.getHost() != null)
230 {
231 String their_host = cs.location.getHost();
232 if (their_host == null)
233 return false;
234 SocketPermission our_sockperm =
235 new SocketPermission(location.getHost(), "accept");
236 SocketPermission their_sockperm =
237 new SocketPermission(their_host, "accept");
238 if (! our_sockperm.implies(their_sockperm))
239 return false;
240 }
241 String our_file = location.getFile();
242 if (our_file != null)
243 {
244 if (! our_file.endsWith("/"))
245 our_file += "/";
246 String their_file = cs.location.getFile();
247 if (their_file == null
248 || ! their_file.startsWith(our_file))
249 return false;
250 }
251 return true;
252 }
253
254 /**
255 * This method returns a <code>String</code> that represents this object.
256 * The result is in the format <code>"(" + getLocation()</code> followed
257 * by a space separated list of certificates (or "<no certificates>"),
258 * followed by <code>")"</code>.
259 *
260 * @return a <code>String</code> for this object
261 */
262 public String toString()
263 {
264 CPStringBuilder sb = new CPStringBuilder("(").append(location);
265 if (certs == null || certs.isEmpty())
266 sb.append(" <no certificates>");
267 else
268 {
269 Iterator iter = certs.iterator();
270 for (int i = certs.size(); --i >= 0; )
271 sb.append(' ').append(iter.next());
272 }
273 return sb.append(")").toString();
274 }
275
276 /**
277 * Reads this object from a serialization stream.
278 *
279 * @param s the input stream
280 * @throws IOException if reading fails
281 * @throws ClassNotFoundException if deserialization fails
282 * @serialData this reads the location, then expects an int indicating the
283 * number of certificates. Each certificate is a String type
284 * followed by an int encoding length, then a byte[] encoding
285 */
286 private void readObject(ObjectInputStream s)
287 throws IOException, ClassNotFoundException
288 {
289 s.defaultReadObject();
290 int count = s.readInt();
291 certs = new HashSet();
292 while (--count >= 0)
293 {
294 String type = (String) s.readObject();
295 int bytes = s.readInt();
296 byte[] encoded = new byte[bytes];
297 for (int i = 0; i < bytes; i++)
298 encoded[i] = s.readByte();
299 ByteArrayInputStream stream = new ByteArrayInputStream(encoded);
300 try
301 {
302 CertificateFactory factory = CertificateFactory.getInstance(type);
303 certs.add(factory.generateCertificate(stream));
304 }
305 catch (CertificateException e)
306 {
307 // XXX Should we ignore this certificate?
308 }
309 }
310 }
311
312 /**
313 * Writes this object to a serialization stream.
314 *
315 * @param s the output stream
316 * @throws IOException if writing fails
317 * @serialData this writes the location, then writes an int indicating the
318 * number of certificates. Each certificate is a String type
319 * followed by an int encoding length, then a byte[] encoding
320 */
321 private void writeObject(ObjectOutputStream s) throws IOException
322 {
323 s.defaultWriteObject();
324 if (certs == null)
325 s.writeInt(0);
326 else
327 {
328 int count = certs.size();
329 s.writeInt(count);
330 Iterator iter = certs.iterator();
331 while (--count >= 0)
332 {
333 Certificate c = (Certificate) iter.next();
334 s.writeObject(c.getType());
335 byte[] encoded;
336 try
337 {
338 encoded = c.getEncoded();
339 }
340 catch (CertificateEncodingException e)
341 {
342 // XXX Should we ignore this certificate?
343 encoded = null;
344 }
345 if (encoded == null)
346 s.writeInt(0);
347 else
348 {
349 s.writeInt(encoded.length);
350 for (int i = 0; i < encoded.length; i++)
351 s.writeByte(encoded[i]);
352 }
353 }
354 }
355 }
356 } // class CodeSource