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    1   /*
    2    * Copyright 2006 University Corporation for Advanced Internet Development, Inc.
    3    *
    4    * Licensed under the Apache License, Version 2.0 (the "License");
    5    * you may not use this file except in compliance with the License.
    6    * You may obtain a copy of the License at
    7    *
    8    * http://www.apache.org/licenses/LICENSE-2.0
    9    *
    10   * Unless required by applicable law or agreed to in writing, software
    11   * distributed under the License is distributed on an "AS IS" BASIS,
    12   * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
    13   * See the License for the specific language governing permissions and
    14   * limitations under the License.
    15   */
    16
    17  package edu.internet2.middleware.shibboleth.idp.authn.provider;
    18
    19  import java.io.IOException;
    20  import java.security.Principal;
    21  import java.util.ArrayList;
    22  import java.util.List;
    23  import java.util.Set;
    24
    25  import javax.security.auth.Subject;
    26  import javax.security.auth.callback.Callback;
    27  import javax.security.auth.callback.CallbackHandler;
    28  import javax.security.auth.callback.NameCallback;
    29  import javax.security.auth.callback.PasswordCallback;
    30  import javax.security.auth.callback.UnsupportedCallbackException;
    31  import javax.servlet.ServletConfig;
    32  import javax.servlet.ServletException;
    33  import javax.servlet.http.HttpServlet;
    34  import javax.servlet.http.HttpServletRequest;
    35  import javax.servlet.http.HttpServletResponse;
    36
    37  import org.opensaml.xml.util.DatatypeHelper;
    38  import org.opensaml.xml.util.Pair;
    39  import org.slf4j.Logger;
    40  import org.slf4j.LoggerFactory;
    41
    42  import edu.internet2.middleware.shibboleth.idp.authn.AuthenticationEngine;
    43  import edu.internet2.middleware.shibboleth.idp.authn.LoginHandler;
    44  import edu.internet2.middleware.shibboleth.idp.authn.UsernamePrincipal;
    45
    46  /**
    47   * This Servlet authenticates a user via JAAS. The user's credential is always added to the returned {@link Subject} as
    48   * a {@link UsernamePasswordCredential} within the subject's private credentials.
    49   */
    50  public class UsernamePasswordLoginServlet extends HttpServlet {
    51
    52      /** Serial version UID. */
    53      private static final long serialVersionUID = -572799841125956990L;
    54
    55      /** Class logger. */
    56      private final Logger log = LoggerFactory.getLogger(UsernamePasswordLoginServlet.class);
    57
    58      /** Name of JAAS configuration used to authenticate users. */
    59      private String jaasConfigName = "ShibUserPassAuth";
    60
    61      /** init-param which can be passed to the servlet to override the default JAAS config. */
    62      private final String jaasInitParam = "jaasConfigName";
    63
    64      /** Login page name. */
    65      private String loginPage = "login.jsp";
    66
    67      /** init-param which can be passed to the servlet to override the default login page. */
    68      private final String loginPageInitParam = "loginPage";
    69
    70      /** Parameter name to indicate login failure. */
    71      private final String failureParam = "loginFailed";
    72
    73      /** HTTP request parameter containing the user name. */
    74      private final String usernameAttribute = "j_username";
    75
    76      /** HTTP request parameter containing the user's password. */
    77      private final String passwordAttribute = "j_password";
    78
    79      /** {@inheritDoc} */
    80      public void init(ServletConfig config) throws ServletException {
    81          super.init(config);
    82
    83          if (getInitParameter(jaasInitParam) != null) {
    84              jaasConfigName = getInitParameter(jaasInitParam);
    85          }
    86
    87          if (getInitParameter(loginPageInitParam) != null) {
    88              loginPage = getInitParameter(loginPageInitParam);
    89          }
    90          if (!loginPage.startsWith("/")) {
    91              loginPage = "/" + loginPage;
    92          }
    93      }
    94
    95      /** {@inheritDoc} */
    96      protected void service(HttpServletRequest request, HttpServletResponse response) throws ServletException,
    97              IOException {
    98          String username = request.getParameter(usernameAttribute);
    99          String password = request.getParameter(passwordAttribute);
    100
    101         if (username == null || password == null) {
    102             redirectToLoginPage(request, response, null);
    103             return;
    104         }
    105
    106         if (authenticateUser(request)) {
    107             AuthenticationEngine.returnToAuthenticationEngine(request, response);
    108         } else {
    109             List<Pair<String, String>> queryParams = new ArrayList<Pair<String, String>>();
    110             queryParams.add(new Pair<String, String>(failureParam, "true"));
    111             redirectToLoginPage(request, response, queryParams);
    112         }
    113     }
    114
    115     /**
    116      * Sends the user to the login page.
    117      *
    118      * @param request current request
    119      * @param response current response
    120      * @param queryParams query parameters to pass to the login page
    121      */
    122     protected void redirectToLoginPage(HttpServletRequest request, HttpServletResponse response,
    123             List<Pair<String, String>> queryParams) {
    124
    125         String requestContext = DatatypeHelper.safeTrimOrNullString(request.getContextPath());
    126         if (requestContext == null) {
    127             requestContext = "/";
    128         }
    129         request.setAttribute("actionUrl", requestContext + request.getServletPath());
    130
    131         if (queryParams != null) {
    132             for (Pair<String, String> param : queryParams) {
    133                 request.setAttribute(param.getFirst(), param.getSecond());
    134             }
    135         }
    136
    137         try {
    138             request.getRequestDispatcher(loginPage).forward(request, response);
    139             log.debug("Redirecting to login page {}", loginPage);
    140         } catch (IOException ex) {
    141             log.error("Unable to redirect to login page.", ex);
    142         } catch (ServletException ex) {
    143             log.error("Unable to redirect to login page.", ex);
    144         }
    145     }
    146
    147     /**
    148      * Authenticate a username and password against JAAS. If authentication succeeds the name of the first principal, or
    149      * the username if that is empty, and the subject are placed into the request in their respective attributes.
    150      *
    151      * @param request current authentication request
    152      *
    153      * @return true of authentication succeeds, false if not
    154      */
    155     protected boolean authenticateUser(HttpServletRequest request) {
    156         String username = DatatypeHelper.safeTrimOrNullString(request.getParameter(usernameAttribute));
    157         String password = DatatypeHelper.safeTrimOrNullString(request.getParameter(passwordAttribute));
    158
    159         try {
    160             log.debug("Attempting to authenticate user {}", username);
    161
    162             SimpleCallbackHandler cbh = new SimpleCallbackHandler(username, password);
    163
    164             javax.security.auth.login.LoginContext jaasLoginCtx = new javax.security.auth.login.LoginContext(
    165                     jaasConfigName, cbh);
    166
    167             jaasLoginCtx.login();
    168             log.debug("Successfully authenticated user {}", username);
    169
    170             Subject loginSubject = jaasLoginCtx.getSubject();
    171
    172             Set<Principal> principals = loginSubject.getPrincipals();
    173             if (principals.isEmpty()) {
    174                 principals.add(new UsernamePrincipal(username));
    175             }
    176
    177             Set<Object> publicCredentials = loginSubject.getPublicCredentials();
    178
    179             Set<Object> privateCredentials = loginSubject.getPrivateCredentials();
    180             privateCredentials.add(new UsernamePasswordCredential(username, password));
    181
    182             Subject userSubject = new Subject(false, principals, publicCredentials, privateCredentials);
    183             request.setAttribute(LoginHandler.SUBJECT_KEY, userSubject);
    184
    185             return true;
    186         } catch (Throwable e) {
    187             log.debug("User authentication for " + username + " failed", e);
    188             return false;
    189         }
    190     }
    191
    192     /**
    193      * A callback handler that provides static name and password data to a JAAS loging process.
    194      *
    195      * This handler only supports {@link NameCallback} and {@link PasswordCallback}.
    196      */
    197     protected class SimpleCallbackHandler implements CallbackHandler {
    198
    199         /** Name of the user. */
    200         private String uname;
    201
    202         /** User's password. */
    203         private String pass;
    204
    205         /**
    206          * Constructor.
    207          *
    208          * @param username The username
    209          * @param password The password
    210          */
    211         public SimpleCallbackHandler(String username, String password) {
    212             uname = username;
    213             pass = password;
    214         }
    215
    216         /**
    217          * Handle a callback.
    218          *
    219          * @param callbacks The list of callbacks to process.
    220          *
    221          * @throws UnsupportedCallbackException If callbacks has a callback other than {@link NameCallback} or
    222          *             {@link PasswordCallback}.
    223          */
    224         public void handle(final Callback[] callbacks) throws UnsupportedCallbackException {
    225
    226             if (callbacks == null || callbacks.length == 0) {
    227                 return;
    228             }
    229
    230             for (Callback cb : callbacks) {
    231                 if (cb instanceof NameCallback) {
    232                     NameCallback ncb = (NameCallback) cb;
    233                     ncb.setName(uname);
    234                 } else if (cb instanceof PasswordCallback) {
    235                     PasswordCallback pcb = (PasswordCallback) cb;
    236                     pcb.setPassword(pass.toCharArray());
    237                 }
    238             }
    239         }
    240     }
    241 }