001 /* Provider.java -- Security provider information
002 Copyright (C) 1998, 1999, 2000, 2002, 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 package java.security;
039
040 import java.io.Serializable;
041 import java.util.Properties;
042
043 /**
044 * This class represents a Java security architecture service provider. The
045 * services provided by a such a provider can range from security algorithms to
046 * key generation.
047 * <p>
048 * Providers are installed by name and version number. See the static
049 * initializer of the {@link java.security.Security} class for the default
050 * security providers installed by this class library.
051 *
052 * @author Aaron M. Renn (arenn@urbanophile.com)
053 */
054 public abstract class Provider
055 extends Properties
056 implements Serializable
057 {
058 private static final long serialVersionUID = -4298000515446427739L;
059
060 /**
061 * This is a textual description of the provider
062 */
063 private String info;
064
065 /**
066 * This is the name of the provider
067 */
068 private String name;
069
070 /**
071 * This is the version number of the provider
072 */
073 private double version;
074
075 /**
076 * This method initializes a new instance of <code>Provider</code> to have
077 * the specified name, version, and description information.
078 *
079 * @param name The name to assign to this <code>Provider</code>.
080 * @param version The version number for this <code>Provider</code>.
081 * @param info A textual description of this provider.
082 */
083 protected Provider(String name, double version, String info)
084 {
085 this.name = name;
086 this.version = version;
087 this.info = info;
088 }
089
090 /**
091 * This method returns the name assigned to this <code>Provider</code>.
092 *
093 * @return The <code>Provider</code>'s name.
094 */
095 public String getName()
096 {
097 return (name);
098 }
099
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 }