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1   /*
2    * ====================================================================
3    * Licensed to the Apache Software Foundation (ASF) under one
4    * or more contributor license agreements.  See the NOTICE file
5    * distributed with this work for additional information
6    * regarding copyright ownership.  The ASF licenses this file
7    * to you under the Apache License, Version 2.0 (the
8    * "License"); you may not use this file except in compliance
9    * with the License.  You may obtain a copy of the License at
10   *
11   *   http://www.apache.org/licenses/LICENSE-2.0
12   *
13   * Unless required by applicable law or agreed to in writing,
14   * software distributed under the License is distributed on an
15   * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
16   * KIND, either express or implied.  See the License for the
17   * specific language governing permissions and limitations
18   * under the License.
19   * ====================================================================
20   *
21   * This software consists of voluntary contributions made by many
22   * individuals on behalf of the Apache Software Foundation.  For more
23   * information on the Apache Software Foundation, please see
24   * <http://www.apache.org/>.
25   *
26   */
27  package org.apache.http.impl.client;
28  
29  import java.security.Principal;
30  
31  import javax.net.ssl.SSLSession;
32  
33  import org.apache.http.HttpConnection;
34  import org.apache.http.annotation.Contract;
35  import org.apache.http.annotation.ThreadingBehavior;
36  import org.apache.http.auth.AuthScheme;
37  import org.apache.http.auth.AuthState;
38  import org.apache.http.auth.Credentials;
39  import org.apache.http.client.UserTokenHandler;
40  import org.apache.http.client.protocol.HttpClientContext;
41  import org.apache.http.conn.ManagedHttpClientConnection;
42  import org.apache.http.protocol.HttpContext;
43  
44  /**
45   * Default implementation of {@link UserTokenHandler}. This class will use
46   * an instance of {@link Principal} as a state object for HTTP connections,
47   * if it can be obtained from the given execution context. This helps ensure
48   * persistent connections created with a particular user identity within
49   * a particular security context can be reused by the same user only.
50   * <p>
51   * DefaultUserTokenHandler will use the user principal of connection
52   * based authentication schemes such as NTLM or that of the SSL session
53   * with the client authentication turned on. If both are unavailable,
54   * {@code null} token will be returned.
55   *
56   * @since 4.0
57   */
58  @Contract(threading = ThreadingBehavior.IMMUTABLE)
59  public class DefaultUserTokenHandler implements UserTokenHandler {
60  
61      public static final DefaultUserTokenHandler INSTANCE = new DefaultUserTokenHandler();
62  
63      @Override
64      public Object getUserToken(final HttpContext context) {
65  
66          final HttpClientContext clientContext = HttpClientContext.adapt(context);
67  
68          Principal userPrincipal = null;
69  
70          final AuthState targetAuthState = clientContext.getTargetAuthState();
71          if (targetAuthState != null) {
72              userPrincipal = getAuthPrincipal(targetAuthState);
73              if (userPrincipal == null) {
74                  final AuthState proxyAuthState = clientContext.getProxyAuthState();
75                  userPrincipal = getAuthPrincipal(proxyAuthState);
76              }
77          }
78  
79          if (userPrincipal == null) {
80              final HttpConnection conn = clientContext.getConnection();
81              if (conn.isOpen() && conn instanceof ManagedHttpClientConnection) {
82                  final SSLSession sslsession = ((ManagedHttpClientConnection) conn).getSSLSession();
83                  if (sslsession != null) {
84                      userPrincipal = sslsession.getLocalPrincipal();
85                  }
86              }
87          }
88  
89          return userPrincipal;
90      }
91  
92      private static Principal getAuthPrincipal(final AuthState authState) {
93          final AuthScheme scheme = authState.getAuthScheme();
94          if (scheme != null && scheme.isComplete() && scheme.isConnectionBased()) {
95              final Credentials creds = authState.getCredentials();
96              if (creds != null) {
97                  return creds.getUserPrincipal();
98              }
99          }
100         return null;
101     }
102 
103 }