1 /*
2 * Licensed to the Apache Software Foundation (ASF) under one
3 * or more contributor license agreements. See the NOTICE file
4 * distributed with this work for additional information
5 * regarding copyright ownership. The ASF licenses this file
6 * to you under the Apache License, Version 2.0 (the
7 * "License"); you may not use this file except in compliance
8 * with the License. You may obtain a copy of the License at
9 *
10 * http://www.apache.org/licenses/LICENSE-2.0
11 *
12 * Unless required by applicable law or agreed to in writing,
13 * software distributed under the License is distributed on an
14 * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
15 * KIND, either express or implied. See the License for the
16 * specific language governing permissions and limitations
17 * under the License.
18 */
19 package org.apache.shiro.authc.pam;
20
21 import org.apache.shiro.authc.AuthenticationException;
22 import org.apache.shiro.authc.AuthenticationInfo;
23 import org.apache.shiro.authc.AuthenticationToken;
24 import org.apache.shiro.realm.Realm;
25
26 import java.util.Collection;
27
28
29 /**
30 * A {@code AuthenticationStrategy} implementation assists the {@link ModularRealmAuthenticator} during the
31 * log-in process in a pluggable realm (PAM) environment.
32 *
33 * <p>The {@code ModularRealmAuthenticator} will consult implementations of this interface on what to do during each
34 * interaction with the configured Realms. This allows a pluggable strategy of whether or not an authentication
35 * attempt must be successful for all realms, only 1 or more realms, no realms, etc.
36 *
37 * @see AllSuccessfulStrategy
38 * @see AtLeastOneSuccessfulStrategy
39 * @see FirstSuccessfulStrategy
40 * @since 0.2
41 */
42 public interface AuthenticationStrategy {
43
44 /**
45 * Method invoked by the ModularAuthenticator signifying that the authentication process is about to begin for the
46 * specified {@code token} - called before any {@code Realm} is actually invoked.
47 *
48 * <p>The {@code AuthenticationInfo} object returned from this method is essentially an empty place holder for
49 * aggregating account data across multiple realms. It should be populated by the strategy implementation over the
50 * course of authentication attempts across the multiple realms. It will be passed into the
51 * {@link #beforeAttempt} calls, allowing inspection of the aggregated account data up to that point in the
52 * multi-realm authentication, allowing any logic to be executed accordingly.
53 *
54 * @param realms the Realms that will be consulted during the authentication process for the specified token.
55 * @param token the Principal/Credential representation to be used during authentication for a corresponding subject.
56 * @return an empty AuthenticationInfo object that will populated with data from multiple realms.
57 * @throws AuthenticationException if the strategy implementation does not wish the Authentication attempt to execute.
58 */
59 AuthenticationInfo beforeAllAttempts(Collection<? extends Realm> realms, AuthenticationToken token) throws AuthenticationException;
60
61 /**
62 * Method invoked by the ModularAuthenticator just prior to the realm being consulted for account data,
63 * allowing pre-authentication-attempt logic for that realm only.
64 *
65 * <p>This method returns an {@code AuthenticationInfo} object that will be used for further interaction with realms. Most
66 * implementations will merely return the {@code aggregate} method argument if they don't have a need to
67 * manipulate it.
68 *
69 * @param realm the realm that will be consulted for {@code AuthenticationInfo} for the specified {@code token}.
70 * @param token the {@code AuthenticationToken} submitted for the subject attempting system log-in.
71 * @param aggregate the aggregated AuthenticationInfo object being used across the multi-realm authentication attempt
72 * @return the AuthenticationInfo object that will be presented to further realms in the authentication process - returning
73 * the {@code aggregate} method argument is the normal case if no special action needs to be taken.
74 * @throws org.apache.shiro.authc.AuthenticationException
75 * an exception thrown by the Strategy implementation if it wishes the login
76 * process for the associated subject (user) to stop immediately.
77 */
78 AuthenticationInfo.html#AuthenticationInfo">AuthenticationInfo beforeAttempt(Realm realm, AuthenticationToken token, AuthenticationInfo aggregate) throws AuthenticationException;
79
80 /**
81 * Method invoked by the ModularAuthenticator just after the given realm has been consulted for authentication,
82 * allowing post-authentication-attempt logic for that realm only.
83 *
84 * <p>This method returns an {@code AuthenticationInfo} object that will be used for further interaction with realms. Most
85 * implementations will merge the {@code singleRealmInfo} into the {@code aggregateInfo} and
86 * just return the {@code aggregateInfo} for continued use throughout the authentication process.</p>
87 *
88 * @param realm the realm that was just consulted for {@code AuthenticationInfo} for the given {@code token}.
89 * @param token the {@code AuthenticationToken} submitted for the subject attempting system log-in.
90 * @param singleRealmInfo the info returned from a single realm.
91 * @param aggregateInfo the aggregate info representing all realms in a multi-realm environment.
92 * @param t the Throwable thrown by the Realm during the attempt, or {@code null} if the method returned normally.
93 * @return the AuthenticationInfo object that will be presented to further realms in the authentication process - returning
94 * the {@code aggregateAccount} method argument is the normal case if no special action needs to be taken.
95 * @throws AuthenticationException an exception thrown by the Strategy implementation if it wishes the login process
96 * for the associated subject (user) to stop immediately.
97 */
98 AuthenticationInfoapache/shiro/authc/AuthenticationInfo.html#AuthenticationInfo">AuthenticationInfoo.html#AuthenticationInfo">AuthenticationInfo afterAttempt(Realm realm, AuthenticationToken token, AuthenticationInfoapache/shiro/authc/AuthenticationInfo.html#AuthenticationInfo">AuthenticationInfo singleRealmInfo, AuthenticationInfo aggregateInfo, Throwable t)
99 throws AuthenticationException;
100
101 /**
102 * Method invoked by the ModularAuthenticator signifying that all of its configured Realms have been consulted
103 * for account data, allowing post-processing after all realms have completed.
104 *
105 * <p>Returns the final AuthenticationInfo object that will be returned from the Authenticator to the authenticate() caller.
106 * This is most likely the aggregate AuthenticationInfo object that has been populated by many realms, but the actual return value is
107 * always up to the implementation.
108 *
109 * @param token the {@code AuthenticationToken} submitted for the subject attempting system log-in.
110 * @param aggregate the aggregate {@code AuthenticationInfo} instance populated by all realms during the log-in attempt.
111 * @return the final {@code AuthenticationInfo} object to return to the Authenticator.authenticate() caller.
112 * @throws AuthenticationException if the Strategy implementation wishes to fail the authentication attempt.
113 */
114 AuthenticationInfocationInfo.html#AuthenticationInfo">AuthenticationInfo afterAllAttempts(AuthenticationToken token, AuthenticationInfo aggregate) throws AuthenticationException;
115 }