001    /* DelegationPermission.java -- kerberos delegation permission
002       Copyright (C) 2006 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 javax.security.auth.kerberos;
040    
041    import java.security.BasicPermission;
042    import java.security.Permission;
043    import java.security.PermissionCollection;
044    import java.util.Enumeration;
045    import java.util.Vector;
046    
047    /**
048     * @since 1.4
049     */
050    public final class DelegationPermission
051        extends BasicPermission
052    {
053      // FIXME: Enable this when serialization works.
054      // private static final long serialVersionUID = 883133252142523922L;
055    
056      /**
057       * Create a new instance with the given name.
058       */
059      public DelegationPermission(String name)
060      {
061        super(name);
062        checkSyntax(name);
063      }
064    
065      /**
066       * Create a new instance with the given name and actions.
067       * 
068       * The name consists of two parts: first the subordinate
069       * service principal, then the target service principal.
070       * Each principal is surrounded by quotes; the two are separated
071       * by a space.
072       * 
073       * @param name the name
074       * @param actions the actions; this is ignored
075       */
076      public DelegationPermission(String name, String actions)
077      {
078        super(name, actions);
079        checkSyntax(name);
080      }
081    
082      private static void checkSyntax(String name)
083      {
084        int index = name.indexOf('"', 1);
085        int len = name.length();
086        if (name.charAt(0) != '"' || name.charAt(len - 1) != '"'
087            || index == -1 || index + 3 >= len
088            || name.charAt(index + 1) != ' '
089            || name.charAt(index + 2) != '"')
090          // FIXME: better message here.
091          throw new IllegalArgumentException("invalid syntax for principals");
092      }
093    
094      public boolean implies(Permission perm)
095      {
096        return equals(perm);
097      }
098    
099      public PermissionCollection newPermissionCollection()
100      {
101        // FIXME: don't know how to serialize here.  I suspect this
102        // class has to have a particular name, etc ...
103        return new PermissionCollection()
104        {
105          private Vector permissions = new Vector();
106    
107          public void add(Permission perm)
108          {
109            if (isReadOnly())
110              throw new SecurityException("readonly");
111            if (! (perm instanceof DelegationPermission))
112              throw new IllegalArgumentException("can only add DelegationPermissions");
113            permissions.add(perm);
114          }
115    
116          public boolean implies(Permission perm)
117          {
118            if (! (perm instanceof DelegationPermission))
119              return false;
120            Enumeration e = elements();
121            while (e.hasMoreElements())
122              {
123                DelegationPermission dp = (DelegationPermission) e.nextElement();
124                if (dp.implies(perm))
125                  return true;
126              }
127            return false;
128          }
129    
130          public Enumeration elements()
131          {
132            return permissions.elements();
133          }
134        };
135      }
136    }