第二十二章 集成验证码——《跟我学Shiro》
目录贴: 跟我学Shiro目录贴
在做用户登录功能时,很多时候都需要验证码支持,验证码的目的是为了防止机器人模拟真实用户登录而恶意访问,如暴力破解用户密码/恶意评论等。目前也有一些验证码比较简单,通过一些OCR工具就可以解析出来;另外还有一些验证码比较复杂(一般通过如扭曲、加线条/噪点等干扰)防止OCR工具识别;但是在中国就是人多,机器干不了的可以交给人来完成,所以在中国就有很多打码平台,人工识别验证码;因此即使比较复杂的如填字、算数等类型的验证码还是能识别的。所以验证码也不是绝对可靠的,目前比较可靠还是手机验证码,但是对于用户来说相对于验证码还是比较麻烦的。
对于验证码图片的生成,可以自己通过如Java提供的图像API自己去生成,也可以借助如JCaptcha这种开源Java类库生成验证码图片;JCaptcha提供了常见的如扭曲、加噪点等干扰支持。本章代码基于《第十六章 综合实例》。
一、添加JCaptcha依赖
- <dependency>
- <groupId>com.octo.captcha</groupId>
- <artifactId>jcaptcha</artifactId>
- <version>2.0-alpha-1</version>
- </dependency>
- <dependency>
- <groupId>com.octo.captcha</groupId>
- <artifactId>jcaptcha-integration-simple-servlet</artifactId>
- <version>2.0-alpha-1</version>
- <exclusions>
- <exclusion>
- <artifactId>servlet-api</artifactId>
- <groupId>javax.servlet</groupId>
- </exclusion>
- </exclusions>
- </dependency>
com.octo.captcha . jcaptcha 提供了jcaptcha 核心;而jcaptcha-integration-simple-servlet提供了与Servlet集成。
二、GMailEngine
来自https://code.google.com/p/musicvalley/source/browse/trunk/musicvalley/doc/springSecurity/springSecurityIII/src/main/java/com/spring/security/jcaptcha/GMailEngine.java?spec=svn447&r=447(目前无法访问了),仿照JCaptcha2.0编写类似GMail验证码的样式;具体请参考com.github.zhangkaitao.shiro.chapter22.jcaptcha.GMailEngine。
三、MyManageableImageCaptchaService
提供了判断仓库中是否有相应的验证码存在。
- public class MyManageableImageCaptchaService extends
- DefaultManageableImageCaptchaService {
- public MyManageableImageCaptchaService(
- com.octo.captcha.service.captchastore.CaptchaStore captchaStore,
- com.octo.captcha.engine.CaptchaEngine captchaEngine,
- int minGuarantedStorageDelayInSeconds,
- int maxCaptchaStoreSize,
- int captchaStoreLoadBeforeGarbageCollection) {
- super(captchaStore, captchaEngine, minGuarantedStorageDelayInSeconds,
- maxCaptchaStoreSize, captchaStoreLoadBeforeGarbageCollection);
- }
- public boolean hasCapcha(String id, String userCaptchaResponse) {
- return store.getCaptcha(id).validateResponse(userCaptchaResponse);
- }
- }
四、JCaptcha工具类
提供相应的API来验证当前请求输入的验证码是否正确。
- public class JCaptcha {
- public static final MyManageableImageCaptchaService captchaService
- = new MyManageableImageCaptchaService(new FastHashMapCaptchaStore(),
- new GMailEngine(), 180, 100000, 75000);
- public static boolean validateResponse(
- HttpServletRequest request, String userCaptchaResponse) {
- if (request.getSession(false) == null) return false;
- boolean validated = false;
- try {
- String id = request.getSession().getId();
- validated =
- captchaService.validateResponseForID(id, userCaptchaResponse)
- .booleanValue();
- } catch (CaptchaServiceException e) {
- e.printStackTrace();
- }
- return validated;
- }
- public static boolean hasCaptcha(
- HttpServletRequest request, String userCaptchaResponse) {
- if (request.getSession(false) == null) return false;
- boolean validated = false;
- try {
- String id = request.getSession().getId();
- validated = captchaService.hasCapcha(id, userCaptchaResponse);
- } catch (CaptchaServiceException e) {
- e.printStackTrace();
- }
- return validated;
- }
- }
validateResponse():验证当前请求输入的验证码否正确;并从CaptchaService中删除已经生成的验证码;
hasCaptcha():验证当前请求输入的验证码是否正确;但不从CaptchaService中删除已经生成的验证码(比如Ajax验证时可以使用,防止多次生成验证码);
五、JCaptchaFilter
用于生成验证码图片的过滤器。
- public class JCaptchaFilter extends OncePerRequestFilter {
- protected void doFilterInternal(HttpServletRequest request, HttpServletResponse response, FilterChain filterChain) throws ServletException, IOException {
- response.setDateHeader("Expires", 0L);
- response.setHeader("Cache-Control", "no-store, no-cache, must-revalidate");
- response.addHeader("Cache-Control", "post-check=0, pre-check=0");
- response.setHeader("Pragma", "no-cache");
- response.setContentType("image/jpeg");
- String id = request.getRequestedSessionId();
- BufferedImage bi = JCaptcha.captchaService.getImageChallengeForID(id);
- ServletOutputStream out = response.getOutputStream();
- ImageIO.write(bi, "jpg", out);
- try {
- out.flush();
- } finally {
- out.close();
- }
- }
- }
CaptchaService使用当前会话ID当作key获取相应的验证码图片;另外需要设置响应内容不进行浏览器端缓存。
- <!-- 验证码过滤器需要放到Shiro之后 因为Shiro将包装HttpSession 如果不,可能造成两次的sesison id 不一样 -->
- <filter>
- <filter-name>JCaptchaFilter</filter-name>
- <filter-class>
- com.github.zhangkaitao.shiro.chapter22.jcaptcha.JCaptchaFilter
- </filter-class>
- </filter>
- <filter-mapping>
- <filter-name>JCaptchaFilter</filter-name>
- <url-pattern>/jcaptcha.jpg</url-pattern>
- </filter-mapping>
这样就可以在页面使用/jcaptcha.jpg地址显示验证码图片。
六、JCaptchaValidateFilter
用于验证码验证的Shiro过滤器。
- public class JCaptchaValidateFilter extends AccessControlFilter {
- private boolean jcaptchaEbabled = true;//是否开启验证码支持
- private String jcaptchaParam = "jcaptchaCode";//前台提交的验证码参数名
- private String failureKeyAttribute = "shiroLoginFailure"; //验证失败后存储到的属性名
- public void setJcaptchaEbabled(boolean jcaptchaEbabled) {
- this.jcaptchaEbabled = jcaptchaEbabled;
- }
- public void setJcaptchaParam(String jcaptchaParam) {
- this.jcaptchaParam = jcaptchaParam;
- }
- public void setFailureKeyAttribute(String failureKeyAttribute) {
- this.failureKeyAttribute = failureKeyAttribute;
- }
- protected boolean isAccessAllowed(ServletRequest request, ServletResponse response, Object mappedValue) throws Exception {
- //1、设置验证码是否开启属性,页面可以根据该属性来决定是否显示验证码
- request.setAttribute("jcaptchaEbabled", jcaptchaEbabled);
- HttpServletRequest httpServletRequest = WebUtils.toHttp(request);
- //2、判断验证码是否禁用 或不是表单提交(允许访问)
- if (jcaptchaEbabled == false || !"post".equalsIgnoreCase(httpServletRequest.getMethod())) {
- return true;
- }
- //3、此时是表单提交,验证验证码是否正确
- return JCaptcha.validateResponse(httpServletRequest, httpServletRequest.getParameter(jcaptchaParam));
- }
- protected boolean onAccessDenied(ServletRequest request, ServletResponse response) throws Exception {
- //如果验证码失败了,存储失败key属性
- request.setAttribute(failureKeyAttribute, "jCaptcha.error");
- return true;
- }
- }
七、MyFormAuthenticationFilter
用于验证码验证的Shiro拦截器在用于身份认证的拦截器之前运行;但是如果验证码验证拦截器失败了,就不需要进行身份认证拦截器流程了;所以需要修改下如FormAuthenticationFilter身份认证拦截器,当验证码验证失败时不再走身份认证拦截器。
- public class MyFormAuthenticationFilter extends FormAuthenticationFilter {
- protected boolean onAccessDenied(ServletRequest request, ServletResponse response, Object mappedValue) throws Exception {
- if(request.getAttribute(getFailureKeyAttribute()) != null) {
- return true;
- }
- return super.onAccessDenied(request, response, mappedValue);
- }
- }
即如果之前已经错了,那直接跳过即可。
八、spring-config-shiro.xml
- <!-- 基于Form表单的身份验证过滤器 -->
- <bean id="authcFilter"
- class="com.github.zhangkaitao.shiro.chapter22.jcaptcha.MyFormAuthenticationFilter">
- <property name="usernameParam" value="username"/>
- <property name="passwordParam" value="password"/>
- <property name="rememberMeParam" value="rememberMe"/>
- <property name="failureKeyAttribute" value="shiroLoginFailure"/>
- </bean>
- <bean id="jCaptchaValidateFilter"
- class="com.github.zhangkaitao.shiro.chapter22.jcaptcha.JCaptchaValidateFilter">
- <property name="jcaptchaEbabled" value="true"/>
- <property name="jcaptchaParam" value="jcaptchaCode"/>
- <property name="failureKeyAttribute" value="shiroLoginFailure"/>
- </bean>
- <!-- Shiro的Web过滤器 -->
- <bean id="shiroFilter" class="org.apache.shiro.spring.web.ShiroFilterFactoryBean">
- <property name="securityManager" ref="securityManager"/>
- <property name="loginUrl" value="/login"/>
- <property name="filters">
- <util:map>
- <entry key="authc" value-ref="authcFilter"/>
- <entry key="sysUser" value-ref="sysUserFilter"/>
- <entry key="jCaptchaValidate" value-ref="jCaptchaValidateFilter"/>
- </util:map>
- </property>
- <property name="filterChainDefinitions">
- <value>
- /static/** = anon
- /jcaptcha* = anon
- /login = jCaptchaValidate,authc
- /logout = logout
- /authenticated = authc
- /** = user,sysUser
- </value>
- </property>
- </bean>
九、login.jsp登录页面
- <c:if test="${jcaptchaEbabled}">
- 验证码:
- <input type="text" name="jcaptchaCode">
- <img class="jcaptcha-btn jcaptcha-img"
- src="${pageContext.request.contextPath}/jcaptcha.jpg" title="点击更换验证码">
- <a class="jcaptcha-btn" href="javascript:;">换一张</a>
- <br/>
- </c:if>
根据jcaptchaEbabled来显示验证码图片。
十、测试
输入http://localhost:8080/chapter22将重定向到登录页面;输入正确的用户名/密码/验证码即可成功登录,如果输入错误的验证码,将显示验证码错误页面:
示例源代码:https://github.com/zhangkaitao/shiro-example;可加群 231889722 探讨Spring/Shiro技术。