package gnu.crypto.sasl.srp;
// ----------------------------------------------------------------------------
// $Id: ClientStore.java,v 1.4 2005/10/06 04:24:18 rsdio Exp $
//
// Copyright (C) 2003 Free Software Foundation, Inc.
//
// This file is part of GNU Crypto.
//
// GNU Crypto is free software; you can redistribute it and/or modify
// it under the terms of the GNU General Public License as published by
// the Free Software Foundation; either version 2, or (at your option)
// any later version.
//
// GNU Crypto is distributed in the hope that it will be useful, but
// WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
// General Public License for more details.
//
// You should have received a copy of the GNU General Public License
// along with this program; see the file COPYING. If not, write to the
//
// Free Software Foundation Inc.,
// 51 Franklin Street, Fifth Floor,
// Boston, MA 02110-1301
// USA
//
// Linking this library statically or dynamically with other modules is
// making a combined work based on this library. Thus, the terms and
// conditions of the GNU General Public License cover the whole
// combination.
//
// As a special exception, the copyright holders of this library give
// you permission to link this library with independent modules to
// produce an executable, regardless of the license terms of these
// independent modules, and to copy and distribute the resulting
// executable under terms of your choice, provided that you also meet,
// for each linked independent module, the terms and conditions of the
// license of that module. An independent module is a module which is
// not derived from or based on this library. If you modify this
// library, you may extend this exception to your version of the
// library, but you are not obligated to do so. If you do not wish to
// do so, delete this exception statement from your version.
// ----------------------------------------------------------------------------
import java.util.HashMap;
/**
* <p>The client-side implementation of the SRP security context store.</p>
*
* @version $Revision: 1.4 $
*/
public class ClientStore {
// Constants and variables
// -------------------------------------------------------------------------
/** The underlying singleton. */
private static ClientStore singleton = null;
/** The map of uid --> SASL Security Context record. */
private static final HashMap uid2ssc = new HashMap();
/** The map of sid --> Session timing record. */
private static final HashMap uid2ttl = new HashMap();
/** A synchronisation lock. */
private static final Object lock = new Object();
// Constructor(s)
// -------------------------------------------------------------------------
/** Private constructor to enforce Singleton pattern. */
private ClientStore() {
super();
// TODO: add a cleaning timer thread
}
// Class methods
// -------------------------------------------------------------------------
/**
* <p>Returns the classloader Singleton.</p>
*
* @return the classloader Singleton instance.
*/
static synchronized final ClientStore instance() {
if (singleton == null) {
singleton = new ClientStore();
}
return singleton;
}
// Instance methods
// -------------------------------------------------------------------------
/**
* <p>Returns a boolean flag indicating if the designated client's session is
* still alive or not.</p>
*
* @param uid the identifier of the client whose session to check.
* @return <code>true</code> if the designated client's session is still
* alive. <code>false</code> otherwise.
*/
boolean isAlive(final String uid) {
final boolean result;
synchronized(lock) {
final Object obj = uid2ssc.get(uid);
result = (obj != null);
if (result) { // is it still alive?
final StoreEntry sto = (StoreEntry) uid2ttl.get(uid);
if (!sto.isAlive()) { // invalidate it
uid2ssc.remove(uid);
uid2ttl.remove(uid);
}
}
}
return result;
}
/**
* <p>Records a mapping between a client's unique identifier and its security
* context.</p>
*
* @param uid the unique identifier of the SRP client for which the session
* is to be cached.
* @param ttl the session's Time-To-Live indicator (in seconds).
* @param ctx the client's security context.
*/
void cacheSession(final String uid, final int ttl, final SecurityContext ctx) {
synchronized(lock) {
uid2ssc.put(uid, ctx);
uid2ttl.put(uid, new StoreEntry(ttl));
}
}
/**
* <p>Removes the mapping between the designated SRP client unique identifier
* and the its session security context (and other timing information).</p>
*
* @param uid the identifier of the client whose session is to invalidate.
*/
void invalidateSession(final String uid) {
synchronized(lock) {
uid2ssc.remove(uid);
uid2ttl.remove(uid);
}
}
/**
* <p>Returns an SRP client's security context record mapped by that client's
* unique identifier.</p>
*
* @param uid the identifier of the client whose session is to restore.
* @return the SRP client's security context.
*/
SecurityContext restoreSession(final String uid) {
final SecurityContext result;
synchronized(lock) {
result = (SecurityContext) uid2ssc.remove(uid);
uid2ttl.remove(uid);
}
return result;
}
}