001    /*
002     * Licensed to the Apache Software Foundation (ASF) under one
003     * or more contributor license agreements.  See the NOTICE file
004     * distributed with this work for additional information
005     * regarding copyright ownership.  The ASF licenses this file
006     * to you under the Apache License, Version 2.0 (the
007     * "License"); you may not use this file except in compliance
008     * with the License.  You may obtain a copy of the License at
009     *
010     *     http://www.apache.org/licenses/LICENSE-2.0
011     *
012     * Unless required by applicable law or agreed to in writing,
013     * software distributed under the License is distributed on an
014     * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
015     * KIND, either express or implied.  See the License for the
016     * specific language governing permissions and limitations
017     * under the License.
018     */
019    package org.apache.shiro.mgt;
020    
021    import org.apache.shiro.authc.AuthenticationException;
022    import org.apache.shiro.authc.AuthenticationInfo;
023    import org.apache.shiro.authc.AuthenticationToken;
024    import org.apache.shiro.authc.Authenticator;
025    import org.apache.shiro.authc.pam.ModularRealmAuthenticator;
026    import org.apache.shiro.util.LifecycleUtils;
027    
028    
029    /**
030     * Shiro support of a {@link SecurityManager} class hierarchy that delegates all
031     * authentication operations to a wrapped {@link Authenticator Authenticator} instance.  That is, this class
032     * implements all the <tt>Authenticator</tt> methods in the {@link SecurityManager SecurityManager}
033     * interface, but in reality, those methods are merely passthrough calls to the underlying 'real'
034     * <tt>Authenticator</tt> instance.
035     *
036     * <p>All other <tt>SecurityManager</tt> (authorization, session, etc) methods are left to be implemented by subclasses.
037     *
038     * <p>In keeping with the other classes in this hierarchy and Shiro's desire to minimize configuration whenever
039     * possible, suitable default instances for all dependencies are created upon instantiation.
040     *
041     * @since 0.9
042     */
043    public abstract class AuthenticatingSecurityManager extends RealmSecurityManager {
044    
045        /**
046         * The internal <code>Authenticator</code> delegate instance that this SecurityManager instance will use
047         * to perform all authentication operations.
048         */
049        private Authenticator authenticator;
050    
051        /**
052         * Default no-arg constructor that initializes its internal
053         * <code>authenticator</code> instance to a
054         * {@link org.apache.shiro.authc.pam.ModularRealmAuthenticator ModularRealmAuthenticator}.
055         */
056        public AuthenticatingSecurityManager() {
057            super();
058            this.authenticator = new ModularRealmAuthenticator();
059        }
060    
061        /**
062         * Returns the delegate <code>Authenticator</code> instance that this SecurityManager uses to perform all
063         * authentication operations.  Unless overridden by the
064         * {@link #setAuthenticator(org.apache.shiro.authc.Authenticator) setAuthenticator}, the default instance is a
065         * {@link org.apache.shiro.authc.pam.ModularRealmAuthenticator ModularRealmAuthenticator}.
066         *
067         * @return the delegate <code>Authenticator</code> instance that this SecurityManager uses to perform all
068         *         authentication operations.
069         */
070        public Authenticator getAuthenticator() {
071            return authenticator;
072        }
073    
074        /**
075         * Sets the delegate <code>Authenticator</code> instance that this SecurityManager uses to perform all
076         * authentication operations.  Unless overridden by this method, the default instance is a
077         * {@link org.apache.shiro.authc.pam.ModularRealmAuthenticator ModularRealmAuthenticator}.
078         *
079         * @param authenticator the delegate <code>Authenticator</code> instance that this SecurityManager will use to
080         *                      perform all authentication operations.
081         * @throws IllegalArgumentException if the argument is <code>null</code>.
082         */
083        public void setAuthenticator(Authenticator authenticator) throws IllegalArgumentException {
084            if (authenticator == null) {
085                String msg = "Authenticator argument cannot be null.";
086                throw new IllegalArgumentException(msg);
087            }
088            this.authenticator = authenticator;
089        }
090    
091        /**
092         * Passes on the {@link #getRealms() realms} to the internal delegate <code>Authenticator</code> instance so
093         * that it may use them during authentication attempts.
094         */
095        protected void afterRealmsSet() {
096            super.afterRealmsSet();
097            if (this.authenticator instanceof ModularRealmAuthenticator) {
098                ((ModularRealmAuthenticator) this.authenticator).setRealms(getRealms());
099            }
100        }
101    
102        /**
103         * Delegates to the wrapped {@link org.apache.shiro.authc.Authenticator Authenticator} for authentication.
104         */
105        public AuthenticationInfo authenticate(AuthenticationToken token) throws AuthenticationException {
106            return this.authenticator.authenticate(token);
107        }
108    
109        public void destroy() {
110            LifecycleUtils.destroy(getAuthenticator());
111            this.authenticator = null;
112            super.destroy();
113        }
114    }