001/* UnresolvedPermission.java -- Placeholder for unresolved permissions
002   Copyright (C) 1998, 2001, 2002, 2004, 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
038
039package java.security;
040
041// All uses of Certificate in this file refer to the one in the listed
042// package, not this one.
043import java.security.cert.Certificate;
044import java.util.Arrays;
045import java.util.Enumeration;
046import java.util.Hashtable;
047import java.util.NoSuchElementException;
048import java.util.Vector;
049
050/**
051 * This class is used to hold instances of all permissions that cannot
052 * be resolved to available permission classes when the security
053 * <code>Policy</code> object is instantiated.  This may happen when the
054 * necessary security class has not yet been downloaded from the network.
055 *
056 * <p>Instances of this class are re-resolved when
057 * <code>AccessController</code> check is done.  At that time, a scan is
058 * made of all existing <code>UnresolvedPermission</code> objects and they
059 * are converted to objects of the appropriate permission type if the class
060 * for that type is then available.
061 *
062 * @author Aaron M. Renn (arenn@urbanophile.com)
063 * @see Permission
064 * @see Permissions
065 * @see PermissionCollection
066 * @see Policy
067 * @since 1.1
068 * @status updated to 1.4
069 */
070public final class UnresolvedPermission extends Permission
071{
072  /**
073   * Compatible with JDK 1.1+.
074   */
075  private static final long serialVersionUID = -4821973115467008846L;
076
077  /**
078   * The list of actions associated with this permission object.
079   *
080   * @serial the permission actions
081   */
082  private final String actions;
083
084  /**
085   * The list of <code>Certificates</code> associated with this object.
086   */
087  private final transient Certificate[] certs;
088
089  /**
090   * The name of the class this object should be resolved to.
091   *
092   * @serial the fully-qualified classname of the resolved type
093   */
094  // Package visible for use by UnresolvedPermissionCollection.
095  final String type;
096
097  /**
098   * The name of the permission.
099   *
100   * @serial the permission name
101   */
102  private final String name;
103
104  /**
105   * Create a new instance with all the information necessary to resolve it
106   * to an instance of the proper class at a future time.
107   *
108   * @param type the fully-qualified name of the class of this permission
109   * @param name the name of this permission
110   * @param actions the action list for this permission
111   * @param certs the list of certificates that sign this permission
112   */
113  public UnresolvedPermission(String type, String name, String actions,
114                              Certificate[] certs)
115  {
116    super(name);
117    this.name = name;
118    this.type = type;
119    this.actions = actions;
120    this.certs = certs;
121  }
122
123  /**
124   * This method returns <code>false</code> always to indicate that this
125   * permission does not imply the specified permission.  An
126   * <code>UnresolvedPermission</code> never grants any permissions.
127   *
128   * @param perm the <code>Permission</code> object to test
129   * @return false; until a permission is resolved, it implies nothing
130   */
131  public boolean implies(Permission perm)
132  {
133    return false;
134  }
135
136  /**
137   * This method tests this permission for equality against the specified
138   * <code>Object</code>. This will be true if and only if the following
139   * conditions are met:<ul>
140   * <li>The specified <code>Object</code> is an UnresolvedPermission</li>
141   * <li>The specified permission has the same type (i.e., desired class name)
142   *     as this permission.</li>
143   * <li>The specified permission has the same name as this one.</li>
144   * <li>The specified permissoin has the same action list as this one.</li>
145   * <li>The specified permission has the same certificate list as this
146   *     one.</li>
147   * </ul>
148   *
149   * @param obj the <code>Object</code> to test for equality
150   * @return true if the specified object is equal to this one
151   */
152  public boolean equals(Object obj)
153  {
154    if (! (obj instanceof UnresolvedPermission))
155      return (false);
156    UnresolvedPermission up = (UnresolvedPermission) obj;
157    return up.name.equals(name) && up.actions.equals(actions)
158      && up.type.equals(type) && Arrays.equals(up.certs, certs);
159  }
160
161  /**
162   * Returns a hash code value for this object. Following the lead of
163   * Permission, this returns the hashcode of the permission name.
164   *
165   * @return A hash value
166   */
167  public int hashCode()
168  {
169    return name.hashCode();
170  }
171
172  /**
173   * This method returns the list of actions associated with this
174   * permission.
175   *
176   * @return the action list
177   */
178  public String getActions()
179  {
180    return actions;
181  }
182
183  /**
184   * This method returns a <code>String</code> representation of this
185   * class.  The format is: '(unresolved "ClassName "name" "actions")'
186   *
187   * @return  <code>String</code> representation of this object
188   */
189  public String toString()
190  {
191    return "(unresolved " + type + ' ' + name + ' ' + actions + ')';
192  }
193
194  /**
195   * This class returns a <code>PermissionCollection</code> object that can
196   * be used to store instances of <code>UnresolvedPermission</code>.
197   *
198   * @return a new <code>PermissionCollection</code>
199   */
200  public PermissionCollection newPermissionCollection()
201  {
202    return new UnresolvedPermissionCollection();
203  }
204
205  /**
206   * Return the name of the class of the unresolved permission.
207   * @since 1.5
208   */
209  public String getUnresolvedType()
210  {
211    return type;
212  }
213
214  /**
215   * Return the name of the unresolved permission.
216   * @since 1.5
217   */
218  public String getUnresolvedName()
219  {
220    return name;
221  }
222
223  /**
224   * Return the actions of the unresolved permission, or null
225   * if there are no actions.
226   * @since 1.5
227   */
228  public String getUnresolvedActions()
229  {
230    return actions;
231  }
232
233  /**
234   * Return the certificates of the unresolved permission.
235   * If there are no certificates, null is returned.  Otherwise,
236   * a new array is returned.
237   * @since 1.5
238   */
239  public Certificate[] getUnresolvedCerts()
240  {
241    if (certs == null)
242      return null;
243    return (Certificate[]) certs.clone();
244  }
245} // class UnresolvedPermission
246
247/**
248 * Implements the permission collection for unresolved permissions, and
249 * obeys serialization of JDK.
250 *
251 * @author Eric Blake (ebb9@email.byu.edu)
252 */
253class UnresolvedPermissionCollection extends PermissionCollection
254{
255  /**
256   * Compatible with JDK 1.1+.
257   */
258  private static final long serialVersionUID = -7176153071733132400L;
259
260  // Package-private to avoid a trampoline.
261  /**
262   * Hashtable where we store permissions.
263   *
264   * @serial map of typename to a Vector of permissions (you'd think Sun
265   *         would document this better!)
266   */
267  final Hashtable permissions = new Hashtable();
268
269  /**
270   * Add a permission.
271   *
272   * @param perm the permission to add
273   * @throws IllegalArgumentException if perm is not an UnresolvedPermission
274   * @throws SecurityException if the collection is read-only
275   */
276  public void add(Permission perm)
277  {
278    if (isReadOnly())
279      throw new SecurityException();
280    if (! (perm instanceof UnresolvedPermission))
281      throw new IllegalArgumentException();
282    UnresolvedPermission up = (UnresolvedPermission) perm;
283    Vector v = (Vector) permissions.get(up.type);
284    if (v == null)
285      {
286        v = new Vector();
287        permissions.put(up.type, v);
288      }
289    v.add(up);
290  }
291
292  /**
293   * Returns true if perm is implied by the collection.
294   *
295   * @param perm the permission to check
296   * @return false; unresolved permissions imply nothing
297   */
298  public boolean implies(Permission perm)
299  {
300    return false;
301  }
302
303  /**
304   * Return the elements.
305   *
306   * @return the elements
307   */
308  public Enumeration elements()
309  {
310    return new Enumeration()
311    {
312      Enumeration main_enum = permissions.elements();
313      Enumeration sub_enum;
314
315      public boolean hasMoreElements()
316      {
317        if (sub_enum == null)
318          {
319            if (main_enum == null)
320              return false;
321            if (! main_enum.hasMoreElements())
322              {
323                main_enum = null;
324                return false;
325              }
326            Vector v = (Vector) main_enum.nextElement();
327            sub_enum = v.elements();
328          }
329        if (! sub_enum.hasMoreElements())
330          {
331            sub_enum = null;
332            return hasMoreElements();
333          }
334        return true;
335      }
336
337      public Object nextElement()
338      {
339        if (! hasMoreElements())
340          throw new NoSuchElementException();
341        return sub_enum.nextElement();
342      }
343    };
344  }
345} // class UnresolvedPermissionCollection