/*
 * $Header: /home/cvs/jakarta-tomcat-4.0/catalina/src/share/org/apache/naming/ContextAccessController.java,v 1.3 2001/06/11 22:44:03 remm Exp $
 * $Revision: 1.3 $
 * $Date: 2001/06/11 22:44:03 $
 *
 * ====================================================================
 *
 * The Apache Software License, Version 1.1
 *
 * Copyright (c) 1999 The Apache Software Foundation.  All rights 
 * reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 *
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer. 
 *
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in
 *    the documentation and/or other materials provided with the
 *    distribution.
 *
 * 3. The end-user documentation included with the redistribution, if
 *    any, must include the following acknowlegement:  
 *       "This product includes software developed by the 
 *        Apache Software Foundation (http://www.apache.org/)."
 *    Alternately, this acknowlegement may appear in the software itself,
 *    if and wherever such third-party acknowlegements normally appear.
 *
 * 4. The names "The Jakarta Project", "Tomcat", and "Apache Software
 *    Foundation" must not be used to endorse or promote products derived
 *    from this software without prior written permission. For written 
 *    permission, please contact apache@apache.org.
 *
 * 5. Products derived from this software may not be called "Apache"
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 *
 * THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESSED OR IMPLIED
 * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
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 * ====================================================================
 *
 * This software consists of voluntary contributions made by many
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 *
 * [Additional notices, if required by prior licensing conditions]
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 */ 


package org.apache.naming;

import java.util.Hashtable;
import javax.naming.NamingException;

/**
 * Handles the access control on the JNDI contexts.
 *
 * @author Remy Maucherat
 * @version $Revision: 1.3 $ $Date: 2001/06/11 22:44:03 $
 */

public class ContextAccessController {


    // -------------------------------------------------------------- Variables


    /**
     * Catalina context names on which writing is not allowed.
     */
    private static Hashtable readOnlyContexts = new Hashtable();


    /**
     * Security tokens repository.
     */
    private static Hashtable securityTokens = new Hashtable();


    // --------------------------------------------------------- Public Methods


    /**
     * Set a security token for a context. Can be set only once.
     * 
     * @param name Name of the context
     * @param context Security token
     */
    public static void setSecurityToken(Object name, Object token) {
        if ((!securityTokens.containsKey(name)) && (token != null)) {
            securityTokens.put(name, token);
        }
    }


    /**
     * Remove a security token for a context.
     * 
     * @param name Name of the context
     * @param context Security token
     */
    public static void unsetSecurityToken(Object name, Object token) {
        if (checkSecurityToken(name, token)) {
            securityTokens.remove(name);
        }
    }


    /**
     * Check a submitted security token. The submitted token must be equal to
     * the token present in the repository. If no token is present for the 
     * context, then returns true.
     * 
     * @param name Name of the context
     * @param context Submitted security token
     */
    public static boolean checkSecurityToken
        (Object name, Object token) {
        Object refToken = securityTokens.get(name);
        if (refToken == null)
            return (true);
        if ((refToken != null) && (refToken.equals(token)))
            return (true);
        return (false);
    }


    /**
     * Allow writing to a context.
     * 
     * @param name Name of the context
     * @param token Security token
     */
    public static void setWritable(Object name, Object token) {
        if (checkSecurityToken(name, token))
            readOnlyContexts.remove(name);
    }


    /**
     * Set whether or not a context is writable.
     * 
     * @param name Name of the context
     */
    public static void setReadOnly(Object name) {
        readOnlyContexts.put(name, name);
    }


    /**
     * Returns if a context is writable.
     * 
     * @param name Name of the context
     */
    public static boolean isWritable(Object name) {
        return !(readOnlyContexts.containsKey(name));
    }


}

