title: Integrating Captcha with Spring Security
body: <p>What is appropriate way to integrate SpringSecurity with Capcha ? </p>
  
  <p>I have following use case :
  When user will tries to login, if we he failed to login N times, captcha will be displayed, so authentication will be using three parameters : username, password, captcha. But Spring Security doesn't support built in Captcha handling. </p>
  
  <p>I just start thinking about implementation. And have following variants:</p>
  
  <ul>
  <li>Adding separate security filter in Spring Security filter stack, </li>
  <li>Entirely rewrite AuthenticationProcessingFilter to support some Captcha</li>
  <li>Use some programmatic authentication with interception captcha logic and then transfering username and password to Spring Security</li>
  </ul>
  
  <p>As a Captcha implementation I think about JCaptcha, but what your thougths?</p>