libjava/classpath/java/security/Provider.java

   1 /* Provider.java -- Security provider information
   2    Copyright (C) 1998, 1999, 2000, 2002, 2006 Free Software Foundation, Inc.
   3
   4 This file is part of GNU Classpath.
   5
   6 GNU Classpath is free software; you can redistribute it and/or modify
   7 it under the terms of the GNU General Public License as published by
   8 the Free Software Foundation; either version 2, or (at your option)
   9 any later version.
  10
  11 GNU Classpath is distributed in the hope that it will be useful, but
  12 WITHOUT ANY WARRANTY; without even the implied warranty of
  13 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  14 General Public License for more details.
  15
  16 You should have received a copy of the GNU General Public License
  17 along with GNU Classpath; see the file COPYING.  If not, write to the
  18 Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
  19 02110-1301 USA.
  20
  21 Linking this library statically or dynamically with other modules is
  22 making a combined work based on this library.  Thus, the terms and
  23 conditions of the GNU General Public License cover the whole
  24 combination.
  25
  26 As a special exception, the copyright holders of this library give you
  27 permission to link this library with independent modules to produce an
  28 executable, regardless of the license terms of these independent
  29 modules, and to copy and distribute the resulting executable under
  30 terms of your choice, provided that you also meet, for each linked
  31 independent module, the terms and conditions of the license of that
  32 module.  An independent module is a module which is not derived from
  33 or based on this library.  If you modify this library, you may extend
  34 this exception to your version of the library, but you are not
  35 obligated to do so.  If you do not wish to do so, delete this
  36 exception statement from your version. */
  37
  38 package java.security;
  39
  40 import java.io.Serializable;
  41 import java.util.Properties;
  42
  43 /**
  44  * This class represents a Java security architecture service provider. The
  45  * services provided by a such a provider can range from security algorithms to
  46  * key generation.
  47  * <p>
  48  * Providers are installed by name and version number. See the static
  49  * initializer of the {@link java.security.Security} class for the default
  50  * security providers installed by this class library.
  51  *
  52  * @author Aaron M. Renn (arenn@urbanophile.com)
  53  */
  54 public abstract class Provider
  55     extends Properties
  56     implements Serializable
  57 {
  58   private static final long serialVersionUID = -4298000515446427739L;
  59
  60   /**
  61    * This is a textual description of the provider
  62    */
  63   private String info;
  64
  65   /**
  66    * This is the name of the provider
  67    */
  68   private String name;
  69
  70   /**
  71    * This is the version number of the provider
  72    */
  73   private double version;
  74
  75   /**
  76    * This method initializes a new instance of <code>Provider</code> to have
  77    * the specified name, version, and description information.
  78    *
  79    * @param name The name to assign to this <code>Provider</code>.
  80    * @param version The version number for this <code>Provider</code>.
  81    * @param info A textual description of this provider.
  82    */
  83   protected Provider(String name, double version, String info)
  84   {
  85     this.name = name;
  86     this.version = version;
  87     this.info = info;
  88   }
  89
  90   /**
  91    * This method returns the name assigned to this <code>Provider</code>.
  92    *
  93    * @return The <code>Provider</code>'s name.
  94    */
  95   public String getName()
  96   {
  97     return (name);
  98   }
  99
 100   /**
 101    * This method retunrs the version number of this <code>Provider</code>.
 102    *
 103    * @return The <code>Provider</code>'s version number.
 104    */
 105   public double getVersion()
 106   {
 107     return (version);
 108   }
 109
 110   /**
 111    * This method returns a textual description of the <code>Provider</code>.
 112    *
 113    * @return A description of the <code>Provider</code>.
 114    */
 115   public String getInfo()
 116   {
 117     return (info);
 118   }
 119
 120   /**
 121    * Maps a key property to a designated value.
 122    * <p>
 123    * If there is an installed {@link SecurityManager} object in the underlying
 124    * VM, its {@link SecurityManager#checkSecurityAccess(String)} method is
 125    * called with the string <code>"putProviderProperty." + name</code>, where
 126    * <code>name</code> is this provider's name. For the default implementation
 127    * this translates into a {@link SecurityManager#checkPermission(Permission)}
 128    * for a <code>SecurityPermission("putProviderProperty." + name)</code>.
 129    *
 130    * @param key The property key.
 131    * @param value The property value.
 132    * @return The previous value of the specified property (<code>key</code>),
 133    *         or <code>null</code> if it did not have one.
 134    * @throws SecurityException If a security manager is installed and its
 135    *           {@link SecurityManager#checkSecurityAccess(String)} method
 136    *           disallows adding properties at run-time.
 137    * @since Classpath 0.4+cvs, JDK 1.2
 138    * @see java.lang.Object#equals(Object)
 139    * @see java.util.Hashtable#get(Object)
 140    */
 141   public Object put(Object key, Object value)
 142   {
 143     SecurityManager sm = System.getSecurityManager();
 144     if (sm != null)
 145       sm.checkSecurityAccess("putProviderProperty." + this.name);
 146     return super.put(toCanonicalKey(key), value);
 147   }
 148
 149   // overrides same in java.util.Hashtable
 150   public Object get(Object key)
 151   {
 152     return super.get(toCanonicalKey(key));
 153   }
 154
 155   /**
 156    * This method removes the specified key entry (and its associated value)
 157    * from the property mapping collection.
 158    * <p>
 159    * If there is an installed {@link SecurityManager} object in the underlying
 160    * VM, its {@link SecurityManager#checkSecurityAccess(String)} method is
 161    * called with the string <code>"removeProviderProperty." + name</code>, where
 162    * <code>name</code> is this provider's name. For the default implementation
 163    * this translates into a {@link SecurityManager#checkPermission(Permission)}
 164    * for a <code>SecurityPermission("removeProviderProperty." + name)</code>.
 165    *
 166    * @param key The key to remove
 167    * @return The previous value for this key, or <code>null</code> if no
 168    * previous value.
 169    */
 170   public Object remove(Object key)
 171   {
 172     SecurityManager sm = System.getSecurityManager();
 173     if (sm != null)
 174       sm.checkSecurityAccess("removeProviderProperty." + this.name);
 175     return super.remove(toCanonicalKey(key));
 176   }
 177
 178   /**
 179    * This method clears the entire property collection such that it no longer
 180    * contains the properties used to look up the services provided by
 181    * this <code>Provider</code>.
 182    * <p>
 183    * If there is an installed {@link SecurityManager} object in the underlying
 184    * VM, its {@link SecurityManager#checkSecurityAccess(String)} method is
 185    * called with the string <code>"clearProviderProperties." + name</code>,
 186    * where <code>name</code> is this provider's name. For the default
 187    * implementation this translates into a
 188    * {@link SecurityManager#checkPermission(Permission)} for a
 189    * <code>SecurityPermission("clearProviderProperties." + name)</code>.
 190    */
 191   public void clear()
 192   {
 193     SecurityManager sm = System.getSecurityManager();
 194     if (sm != null)
 195       sm.checkSecurityAccess("clearProviderProperties." + this.name);
 196     super.clear();
 197   }
 198
 199   /**
 200    * This method returns a <code>String</code> representation of this
 201    * object.  This will include the <code>Provider</code> name and
 202    * version number.
 203    *
 204    * @return A <code>String</code> representation of this object.
 205    */
 206   public String toString()
 207   {
 208     return (getClass().getName() + ": name=" + getName() + " version=" +
 209             version);
 210   }
 211
 212   private Object toCanonicalKey(Object key)
 213   {
 214     if (key.getClass().isAssignableFrom(String.class)) // is it ours?
 215       return ((String) key).toUpperCase(); // use default locale
 216     return key;
 217   }
 218 }