1   /*
2    * $HeadURL: https://svn.apache.org/repos/asf/httpcomponents/oac.hc3x/trunk/src/test/org/apache/commons/httpclient/server/ProxyAuthRequestHandler.java $
3    * $Revision: 1425331 $
4    * $Date: 2012-12-22 19:29:41 +0100 (Sat, 22 Dec 2012) $
5    *
6    * ====================================================================
7    *
8    *  Licensed to the Apache Software Foundation (ASF) under one or more
9    *  contributor license agreements.  See the NOTICE file distributed with
10   *  this work for additional information regarding copyright ownership.
11   *  The ASF licenses this file to You under the Apache License, Version 2.0
12   *  (the "License"); you may not use this file except in compliance with
13   *  the License.  You may obtain a copy of the License at
14   *
15   *      http://www.apache.org/licenses/LICENSE-2.0
16   *
17   *  Unless required by applicable law or agreed to in writing, software
18   *  distributed under the License is distributed on an "AS IS" BASIS,
19   *  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
20   *  See the License for the specific language governing permissions and
21   *  limitations under the License.
22   * ====================================================================
23   *
24   * This software consists of voluntary contributions made by many
25   * individuals on behalf of the Apache Software Foundation.  For more
26   * information on the Apache Software Foundation, please see
27   * <http://www.apache.org/>.
28   *
29   */
30  
31  package org.apache.commons.httpclient.server;
32  
33  import java.io.IOException;
34  
35  import org.apache.commons.httpclient.Credentials;
36  import org.apache.commons.httpclient.Header;
37  import org.apache.commons.httpclient.HttpStatus;
38  import org.apache.commons.httpclient.UsernamePasswordCredentials;
39  import org.apache.commons.httpclient.auth.BasicScheme;
40  
41  /***
42   * This request handler guards access to a proxy when used in a request handler
43   * chain. It checks the headers for valid credentials and performs the
44   * authentication handshake if necessary.
45   * 
46   * @author Ortwin Glueck
47   * @author Oleg Kalnichevski
48   */
49  public class ProxyAuthRequestHandler implements HttpRequestHandler {
50  
51      private Credentials credentials = null;
52      private String realm = null;
53      private boolean keepalive = true;
54  
55      /***
56       * The proxy authenticate response header.
57       */
58      public static final String PROXY_AUTH_RESP = "Proxy-Authorization";
59  
60      /***
61       * TODO replace creds parameter with a class specific to an auth scheme
62       * encapsulating all required information for a specific scheme
63       * 
64       * @param creds
65       */
66      public ProxyAuthRequestHandler(final Credentials creds, final String realm, boolean keepalive) {
67          if (creds == null)
68              throw new IllegalArgumentException("Credentials may not be null");
69          this.credentials = creds;
70          this.keepalive = keepalive;
71          if (realm != null) {
72              this.realm = realm;
73          } else {
74              this.realm = "test";
75          }
76      }
77  
78      public ProxyAuthRequestHandler(final Credentials creds, final String realm) {
79          this(creds, realm, true);
80      }
81      
82      public ProxyAuthRequestHandler(final Credentials creds) {
83          this(creds, null, true);
84      }
85  
86      public boolean processRequest(
87          final SimpleHttpServerConnection conn,
88          final SimpleRequest request) throws IOException
89      {
90          Header clientAuth = request.getFirstHeader(PROXY_AUTH_RESP);
91          if (clientAuth != null && checkAuthorization(clientAuth)) {
92              return false;
93          } else {
94              SimpleResponse response = performBasicHandshake(conn, request);
95              // Make sure the request body is fully consumed
96              request.getBodyBytes();
97              conn.writeResponse(response);
98              return true;
99          }
100     }
101 
102     //TODO add more auth schemes
103     private SimpleResponse performBasicHandshake(
104             final SimpleHttpServerConnection conn, 
105             final SimpleRequest request) { 
106 
107         SimpleResponse response = new SimpleResponse();
108         response.setStatusLine(
109                 request.getRequestLine().getHttpVersion(),
110                 HttpStatus.SC_PROXY_AUTHENTICATION_REQUIRED);
111         if (!request.getRequestLine().getMethod().equalsIgnoreCase("HEAD")) {
112             response.setBodyString("unauthorized");
113         }
114         response.addHeader(new Header("Proxy-Authenticate", "basic realm=\"" + this.realm + "\""));
115         if (this.keepalive) {
116             response.addHeader(new Header("Proxy-Connection", "keep-alive"));
117             conn.setKeepAlive(true);
118         } else {
119             response.addHeader(new Header("Proxy-Connection", "close"));
120             conn.setKeepAlive(false);
121         }
122         return response;
123     }
124 
125     /***
126      * Checks if the credentials provided by the client match the required
127      * credentials
128      * 
129      * @return true if the client is authorized, false if not.
130      * @param clientAuth
131      */
132     private boolean checkAuthorization(Header clientAuth) {
133         String expectedAuthString = BasicScheme.authenticate(
134             (UsernamePasswordCredentials)credentials,
135             "ISO-8859-1");
136         return expectedAuthString.equals(clientAuth.getValue());
137     }
138 
139 }