1 /* AbstractSessionContext -- stores SSL sessions, possibly persistently. 2 Copyright (C) 2006 Free Software Foundation, Inc. 3 4 This file is a 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 of the License, or (at 9 your option) 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; if not, write to the Free Software 18 Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 19 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 39 package gnu.javax.net.ssl; 40 41 import gnu.java.security.Requires; 42 43 import gnu.javax.net.ssl.provider.SimpleSessionContext; 44 45 import java.util.Enumeration; 46 47 import javax.net.ssl.SSLException; 48 import javax.net.ssl.SSLPermission; 49 import javax.net.ssl.SSLSession; 50 import javax.net.ssl.SSLSessionContext; 51 52 /** 53 * A skeletal implementation of {@link SSLSessionContext}. This class may 54 * be subclassed to add extended functionality to session contexts, such 55 * as by storing sessions in files on disk, or by sharing contexts 56 * across different JVM instances. 57 * 58 * <p>In order to securely store sessions, along with private key data, 59 * the abstract methods {@lnk {@link #load(char[])} and {@link #store(char[])} 60 * come into play. When storing sessions, a session context implementation 61 * must pass this password to the {@link Session#prepare(char[])} method, 62 * before either writing the {@link java.io.Serializable} session to the 63 * underlying store, or getting the opaque {@link Session#privateData()} 64 * class from the session, and storing that. 65 * 66 * <p>As a simple example, that writes sessions to some object output 67 * stream: 68 * 69 * <pre> 70 char[] password = ...; 71 ObjectOutputStream out = ...; 72 ... 73 for (Session s : this) 74 { 75 s.prepare(password); 76 out.writeObject(s); 77 }</pre> 78 * 79 * <p>The reverse must be done when deserializing sessions, by using the 80 * {@link Session#repair(char[])} method, possibly by first calling 81 * {@link Session#setPrivateData(java.io.Serializable)} with the read, 82 * opaque private data type. Thus an example of reading may be: 83 * 84 * <pre> 85 char[] password = ...; 86 ObjectInputStream in = ...; 87 ... 88 while (hasMoreSessions(in)) 89 { 90 Session s = (Session) in.readObject(); 91 s.repair(password); 92 addToThisStore(s); 93 }</pre> 94 * 95 * @author Casey Marshall (csm@gnu.org) 96 */ 97 public abstract class AbstractSessionContext implements SSLSessionContext 98 { 99 protected long timeout; 100 private static Class<? extends AbstractSessionContext> 101 implClass = SimpleSessionContext.class; 102 103 /** 104 * Create a new instance of a session context, according to the configured 105 * implementation class. 106 * 107 * @return The new session context. 108 * @throws SSLException If an error occurs in creating the instance. 109 */ newInstance()110 public static AbstractSessionContext newInstance () throws SSLException 111 { 112 try 113 { 114 return implClass.newInstance(); 115 } 116 catch (IllegalAccessException iae) 117 { 118 throw new SSLException(iae); 119 } 120 catch (InstantiationException ie) 121 { 122 throw new SSLException(ie); 123 } 124 } 125 126 /** 127 * Reconfigure this instance to use a different session context 128 * implementation. 129 * 130 * <p><strong>Note:</strong> this method requires that the caller have 131 * {@link SSLPermission} with target 132 * <code>gnu.javax.net.ssl.AbstractSessionContext</code> and action 133 * <code>setImplClass</code>. 134 * 135 * @param clazz The new implementation class. 136 * @throws SecurityException If the caller does not have permission to 137 * change the session context. 138 */ 139 @Requires(permissionClass = SSLPermission.class, 140 target = "gnu.javax.net.ssl.AbstractSessionContext", 141 action = "setImplClass") setImplClass(Class<? extends AbstractSessionContext> clazz)142 public static synchronized void setImplClass 143 (Class<? extends AbstractSessionContext> clazz) 144 throws SecurityException 145 { 146 SecurityManager sm = System.getSecurityManager (); 147 if (sm != null) 148 sm.checkPermission(new SSLPermission("gnu.javax.net.ssl.AbstractSessionContext", 149 "setImplClass")); 150 implClass = clazz; 151 } 152 153 /** 154 * @param timeout The initial session timeout. 155 */ AbstractSessionContext(final int timeout)156 protected AbstractSessionContext (final int timeout) 157 { 158 setSessionTimeout(timeout); 159 } 160 161 /** 162 * Fetch a saved session by its ID. This method will (possibly) 163 * deserialize and return the SSL session with that ID, or null if 164 * the requested session does not exist, or has expired. 165 * 166 * <p>Subclasses implementing this class <strong>must not</strong> 167 * perform any blocking operations in this method. If any blocking 168 * behavior is required, it must be done in the {@link load(char[])} 169 * method. 170 * 171 * @param sessionId The ID of the session to get. 172 * @return The found session, or null if no such session was found, 173 * or if that session has expired. 174 */ getSession(byte[] sessionId)175 public final SSLSession getSession (byte[] sessionId) 176 { 177 Session s = implGet (sessionId); 178 if (s != null 179 && System.currentTimeMillis () - s.getLastAccessedTime () > timeout) 180 { 181 remove (sessionId); 182 return null; 183 } 184 return s; 185 } 186 getSession(String host, int port)187 public final SSLSession getSession(String host, int port) 188 { 189 for (Enumeration e = getIds(); e.hasMoreElements(); ) 190 { 191 byte[] id = (byte[]) e.nextElement(); 192 SSLSession s = getSession(id); 193 if (s == null) // session expired. 194 continue; 195 String host2 = s.getPeerHost(); 196 if (host == null) 197 { 198 if (host2 != null) 199 continue; 200 } 201 else if (!host.equals(host2)) 202 continue; 203 int port2 = s.getPeerPort(); 204 if (port != port2) 205 continue; 206 207 // Else, a match. 208 return s; 209 } 210 211 return null; 212 } 213 214 /** 215 * To be implemented by subclasses. Subclasses do not need to check 216 * timeouts in this method. 217 * 218 * @param sessionId The session ID. 219 * @return The session, or <code>null</code> if the requested session 220 * was not found. 221 */ implGet(byte[] sessionId)222 protected abstract Session implGet (byte[] sessionId); 223 getSessionTimeout()224 public int getSessionTimeout() 225 { 226 return (int) (timeout / 1000); 227 } 228 229 /** 230 * Load this session store from the underlying media, if supported 231 * by the implementation. 232 * 233 * @param password The password that protects the sensitive data in 234 * this store. 235 * @throws SessionStoreException If reading this store fails, such 236 * as when an I/O exception occurs, or if the password is incorrect. 237 */ load(char[] password)238 public abstract void load (char[] password) throws SessionStoreException; 239 240 /** 241 * Add a new session to the store. The underlying implementation 242 * will add the session to its store, possibly overwriting any 243 * existing session with the same ID. 244 * 245 * <p>Subclasses implementing this class <strong>must not</strong> 246 * perform any blocking operations in this method. If any blocking 247 * behavior is required, it must be done in the {@link 248 * #store(char[])} method. 249 * 250 * @param session The session to add. 251 * @throws NullPointerException If the argument is null. 252 */ put(Session session)253 public abstract void put (Session session); 254 255 /** 256 * Remove a session from this store. 257 * 258 * <p>Subclasses implementing this class <strong>must not</strong> 259 * perform any blocking operations in this method. If any blocking 260 * behavior is required, it must be done in the {@link 261 * #store(char[])} method. 262 * 263 * @param sessionId The ID of the session to remove. 264 */ remove(byte[] sessionId)265 public abstract void remove (byte[] sessionId); 266 267 /** 268 * 269 */ setSessionTimeout(int seconds)270 public final void setSessionTimeout(int seconds) 271 { 272 if (timeout < 0) 273 throw new IllegalArgumentException("timeout may not be negative"); 274 this.timeout = (long) seconds * 1000; 275 } 276 277 /** 278 * Commit this session store to the underlying media. For session 279 * store implementations that support saving sessions across 280 * invocations of the JVM, this method will save any sessions that 281 * have not expired to some persistent media, so they may be loaded 282 * and used again later. 283 * 284 * @param password The password that will protect the sensitive data 285 * in this store. 286 */ store(char[] password)287 public abstract void store (char[] password) throws SessionStoreException; 288 } 289