Source for java.security.Provider

   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: }