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1   /* Copyright 2004, 2005, 2006 Acegi Technology Pty Limited
2    *
3    * Licensed under the Apache License, Version 2.0 (the "License");
4    * you may not use this file except in compliance with the License.
5    * You may obtain a copy of the License at
6    *
7    *     http://www.apache.org/licenses/LICENSE-2.0
8    *
9    * Unless required by applicable law or agreed to in writing, software
10   * distributed under the License is distributed on an "AS IS" BASIS,
11   * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
12   * See the License for the specific language governing permissions and
13   * limitations under the License.
14   */
15  
16  package org.acegisecurity.captcha;
17  
18  import org.springframework.util.Assert;
19  
20  
21  /**
22   * <p>return false if thresold is lower than average time millis between any CaptchaChannelProcessorTemplate mapped
23   * urls requests and is human;<br>
24   * Default keyword : REQUIRES_CAPTCHA_BELOW_AVERAGE_TIME_IN_MILLIS_REQUESTS <br>
25   * Note : before first humanity check</p>
26   *
27   * @author Marc-Antoine Garrigue
28   * @version $Id: AlwaysTestBelowAverageTimeInMillisBetweenRequestsChannelProcessor.java 1496 2006-05-23 13:38:33Z benalex $
29   */
30  public class AlwaysTestBelowAverageTimeInMillisBetweenRequestsChannelProcessor extends CaptchaChannelProcessorTemplate {
31      //~ Static fields/initializers =====================================================================================
32  
33      /** Keyword for this channelProcessor */
34      public static final String DEFAULT_KEYWORD = "REQUIRES_CAPTCHA_BELOW_AVERAGE_TIME_IN_MILLIS_REQUESTS";
35  
36      //~ Constructors ===================================================================================================
37  
38  /**
39       * Constructor
40       */
41      public AlwaysTestBelowAverageTimeInMillisBetweenRequestsChannelProcessor() {
42          super();
43          this.setKeyword(DEFAULT_KEYWORD);
44      }
45  
46      //~ Methods ========================================================================================================
47  
48      /**
49       * Verify if thresold is &gt; 0
50       *
51       * @throws Exception if false
52       */
53      public void afterPropertiesSet() throws Exception {
54          super.afterPropertiesSet();
55          Assert.isTrue(getThresold() > 0, "thresold must be > 0");
56      }
57  
58      /**
59       * Verify wheter the context is valid concerning humanity
60       *
61       * @param context
62       *
63       * @return true if valid, false otherwise
64       */
65      boolean isContextValidConcerningHumanity(CaptchaSecurityContext context) {
66          int req = context.getHumanRestrictedResourcesRequestsCount();
67          float thresold = getThresold();
68          float duration = System.currentTimeMillis() - context.getLastPassedCaptchaDateInMillis();
69          float average;
70  
71          if (req == 0) {
72              average = thresold + 1;
73          } else {
74              average = duration / req;
75          }
76  
77          if (context.isHuman() && (average > thresold)) {
78              logger.debug("context is valid : average time between requests < thresold && is human");
79  
80              return true;
81          } else {
82              logger.debug("context is not valid : request count > thresold or is not human");
83  
84              return false;
85          }
86      }
87  }