How to Integrate JCaptcha in Spring Security

The repository for JCaptcha is this one:

<repository>
        <id>sourceforge-releases</id>
        <name>Sourceforge Releases</name>
        <url>https://oss.sonatype.org/content/repositories/sourceforge-releases</url>
    </repository>

<dependency>
        <groupId>com.octo.captcha</groupId>
        <artifactId>jcaptcha-integration-simple-servlet</artifactId>
        <version>2.0-alpha-1</version>
    </dependency>

Here are some configuration I made in .xml files:

web.xml

<context-param>
    <param-name>contextConfigLocation</param-name>
    <param-value>
        /WEB-INF/applicationContext.xml
        /WEB-INF/spring/spring-security.xml
    </param-value>
</context-param>
 <listener>
    <listener-class>org.springframework.security.web.session.HttpSessionEventPublisher</listener-class>
</listener>

<filter>
    <filter-name>springSecurityFilterChain</filter-name>
    <filter-class>org.springframework.web.filter.DelegatingFilterProxy</filter-class>
</filter>

<filter-mapping>
    <filter-name>springSecurityFilterChain</filter-name>
    <url-pattern>/*</url-pattern>
    <dispatcher>FORWARD</dispatcher>
    <dispatcher>REQUEST</dispatcher>
</filter-mapping>

<servlet>
    <servlet-name>jcaptcha</servlet-name>
    <servlet-class>com.octo.captcha.module.servlet.image.SimpleImageCaptchaServlet</servlet-class>
</servlet>
<servlet-mapping>
    <servlet-name>jcaptcha</servlet-name>
    <url-pattern>/jcaptcha.jpg</url-pattern>
</servlet-mapping>

spring-security.xml

<http auto-config="true" use-expressions="true">
    <intercept-url pattern="/resources/**" access="permitAll()" />
    <intercept-url pattern="/jcaptcha.jpg" access="permitAll()" />
    <intercept-url pattern="/**" access="isAuthenticated()" />

    <form-login login-page="/session/login/" default-target-url="/"
                authentication-failure-url="/session/loginfailed/" />
    <logout logout-success-url="/session/logout/" />
    <access-denied-handler error-page="/session/403/" />

    <!--JCaptcha Filtering-->
    <custom-filter ref="captchaCaptureFilter" before="FORM_LOGIN_FILTER"/>
    <!-- REMOVED custom-filter ref="captchaVerifierFilter" after="FORM_LOGIN_FILTER"/-->
    <anonymous />
</http>

<!-- For capturing CAPTCHA fields -->
<beans:bean id="captchaCaptureFilter" class="com.util.CaptchaCaptureFilter" />

<!-- For verifying CAPTCHA fields -->
<!-- Private key is assigned by the JCaptcha service -->
<!-- REMOVED beans:bean id="captchaVerifierFilter" class="com.util.CaptchaVerifierFilter"
      p:failureUrl="/session/loginfailed/"
      p:captchaCaptureFilter-ref="captchaCaptureFilter"/-->

    <beans:property name="sessionAuthenticationStrategy" ref="sas"/>
    <beans:property name="authenticationManager" ref="authenticationManager" />
    <beans:property name="allowSessionCreation" value="true" />
</beans:bean>

<beans:bean id="sas" class="org.springframework.security.web.authentication.session.ConcurrentSessionControlStrategy">
    <beans:constructor-arg name="sessionRegistry" ref="sessionRegistry"/>
    <beans:property name="maximumSessions" value="1" />
</beans:bean>

<beans:bean id="sessionRegistry" class="org.springframework.security.core.session.SessionRegistryImpl" />

<beans:bean id="userService" class="com.service.mybatis.UserManager" />

<beans:bean id="customAuthenticationProvider" class="com.util.MyAuthenticationProvider" p:captchaCaptureFilter-ref="captchaCaptureFilter" />
<authentication-manager alias="authenticationManager">
    <authentication-provider ref="customAuthenticationProvider" />
</authentication-manager>

<beans:bean id="accessDeniedHandler" class="com.util.ThouShaltNoPass">
    <beans:property name="accessDeniedURL" value="/session/403/" />
</beans:bean>

And these are the java classes:

MyAuthenticationProvider.java

public class MyAuthenticationProvider implements AuthenticationProvider {

@Autowired
private UserService userService;
private Logger logger = LoggerFactory.getLogger(ArtajasaAuthenticationProvider.class);
private CaptchaCaptureFilter captchaCaptureFilter;

@Override
public Authentication authenticate(Authentication authentication) throws AuthenticationException {
    String username = String.valueOf(authentication.getPrincipal());
    String password = String.valueOf(authentication.getCredentials());
    logger.debug("Checking authentication for user {}", username);
    logger.debug("userResponse: {}", captchaCaptureFilter.getUserCaptchaResponse());
    if (StringUtils.isBlank(username)
            || StringUtils.isBlank(password)) {
        throw new BadCredentialsException("No Username and/or Password Provided.");
    }
    else if(StringUtils.isBlank(captchaCaptureFilter.getUserCaptchaResponse())) {
        throw new BadCredentialsException("Captcha Response is Empty");
    }
    else {
        // Send HTTP request to validate user's Captcha
        boolean captchaPassed = SimpleImageCaptchaServlet.validateResponse(captchaCaptureFilter.getRequest(), captchaCaptureFilter.getUserCaptchaResponse());

        // Check if valid
        if (captchaPassed) {
            logger.debug("Captcha is valid!");
            resetCaptchaFields();

            Pengguna user = userService.select(username);
            if (user == null) {
                throw new BadCredentialsException("Invalid Username and/or Password.");
            }
            if (user.getPassword().equals(new PasswordUtil().generateHash(password, user.getSalt()))) {
                List<GrantedAuthority> authorityList = (List<GrantedAuthority>) userService.getAuthorities(user);
                return new UsernamePasswordAuthenticationToken(username, password, authorityList);
            }
            else {
                throw new BadCredentialsException("Invalid Username and/or Password.");
            }
        }
        else {
            logger.debug("Captcha is invalid!");
            resetCaptchaFields();

            throw new BadCredentialsException("Invalid Captcha.");
        }
    }
}

@Override
public boolean supports(Class<?> authentication) {
    return (UsernamePasswordAuthenticationToken.class.isAssignableFrom(authentication));
}

/**
 * Reset Captcha fields
 */
public void resetCaptchaFields() {
    captchaCaptureFilter.setUserCaptchaResponse(null);
}

public CaptchaCaptureFilter getCaptchaCaptureFilter() {
    return captchaCaptureFilter;
}

public void setCaptchaCaptureFilter(CaptchaCaptureFilter captchaCaptureFilter) {
    this.captchaCaptureFilter = captchaCaptureFilter;
}
}

CaptchaCaptureFilter.java

public class CaptchaCaptureFilter extends OncePerRequestFilter {

private Logger logger = Logger.getLogger(CaptchaCaptureFilter.class);
private String userCaptchaResponse;
private HttpServletRequest request;

@Override
public void doFilterInternal(HttpServletRequest req, HttpServletResponse res,
                             FilterChain chain) throws IOException, ServletException {

    logger.debug("Captcha capture filter");

    // Assign values only when user has submitted a Captcha value.
    // Without this condition the values will be reset due to redirection
    // and CaptchaVerifierFilter will enter an infinite loop
    if (req.getParameter("jcaptcha") != null) {
        request = req;
        userCaptchaResponse = req.getParameter("jcaptcha");
    }

    logger.debug("userResponse: " + userCaptchaResponse);

    // Proceed with the remaining filters
    chain.doFilter(req, res);
}

public String getUserCaptchaResponse() {
    return userCaptchaResponse;
}

public void setUserCaptchaResponse(String userCaptchaResponse) {
    this.userCaptchaResponse = userCaptchaResponse;
}

public HttpServletRequest getRequest() {
    return request;
}

public void setRequest(HttpServletRequest request) {
    this.request = request;
}
}

Last but not least, login.jsp

<%@ taglib prefix='c' uri='http://java.sun.com/jstl/core_rt' %>

<form id="login" name="f" action="<c:url value='/j_spring_security_check'/>" method="POST">
  <div class="container">

    <div class="content">
        <div class="row">
            <div class="login-form">
                <h3>Login</h3>
                <br />
                  <fieldset>
                       <div class="clearfix">
                            username: ecr
                            <input type="text" name='j_username' value='<c:if test="${not empty param.login_error}"><c:out value="${SPRING_SECURITY_LAST_USERNAME}"/></c:if>' placeholder="[e-mail]">
                       </div>
                       <div class="clearfix">
                           password: ecr123
                           <input type="password" name='j_password' placeholder="password">
                       </div>
                       <div class="clearfix">
                           <img src="../../jcaptcha.jpg" />
                           <br />
                           <input type="text" name="jcaptcha" placeholder="masukkan captcha" />
                       </div>
                       <br />
                       <button class="btn btn-primary" type="submit"><i class="icon-lock"></i> Sign in</button>
                   </fieldset>
            </div>
        </div>
    </div>
     <br />
     <c:if test="${not empty error}">
            <div class="alert alert-error">
            <button type="button" class="close" data-dismiss="alert"><i class="icon-remove"></i></button>
            Login Failed, try again.<br />
            <c:out value="${sessionScope['SPRING_SECURITY_LAST_EXCEPTION'].message}"/>
            </div>
          </c:if>
  </div>

done!