防止跨站请求伪造(CSRF)攻击 和 防重复提交 的方法的实现

CSRF的概念可以参考：http://netsecurity.51cto.com/art/200812/102951.htm

本文介绍的是基于spring拦截器的Spring MVC实现

 首先配置拦截器：

<mvc:interceptors>    
    <mvc:interceptor>    
        <!-- 匹配的是url路径， 如果不配置或/**,将拦截所有的Controller -->  
        <mvc:mapping path="/xxx/**" />  
        <bean class="com.xxx.SecurityTokenInterceptor"></bean>    
    </mvc:interceptor>  
    <!-- 当设置多个拦截器时，先按顺序调用preHandle方法，然后逆序调用每个拦截器的postHandle和afterCompletion方法 -->  
</mvc:interceptors> 

SecurityTokenInterceptor代码如下

import java.io.IOException;
import java.lang.reflect.Method;
import java.util.UUID;
import java.util.concurrent.ConcurrentHashMap;
import java.util.concurrent.ConcurrentMap;

import javax.servlet.http.Cookie;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;

import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import org.springframework.util.StringUtils;
import org.springframework.web.method.HandlerMethod;
import org.springframework.web.servlet.ModelAndView;
import org.springframework.web.servlet.handler.HandlerInterceptorAdapter;



/**
 * 防止重复提交过滤器
 *
 */

public class SecurityTokenInterceptor extends HandlerInterceptorAdapter {
    private static final Logger duplicateAvoidLOG =  LoggerFactory
            .getLogger(SecurityTokenInterceptor.class);
    
    public static final String DUPLICATEAVOID_TOKEN = "duplicateAvoid_token";
    public static final String PAGE_DUPLICATEAVOID_TOKEN = "sumbit_token";
//    private static final ConcurrentMap<String, String> tokenMap = new  ConcurrentHashMap<String, String>();
    public static final int expressTime = 60 * 60 * 24 * 5;
    public static final String TOKEN_ERROR_CODE ="duplicate_Error"; 
    public static final ThreadLocal<String> threadtoken = new ThreadLocal<String>();
    
    
    
    /**
     * 前置处理器中 检查  DuplicateAvoid注解
     */
    @Override
    public boolean preHandle(HttpServletRequest request, HttpServletResponse response, Object handler){
         duplicateAvoidLOG.info("DuplicateAvoidSubmitInterceptor start,[client:" + getRemoteHost(request) + ",url:"
                 + request.getServletPath() + "]");
        if (handler instanceof HandlerMethod) {
               HandlerMethod handlerMethod = (HandlerMethod) handler;
               Method method = handlerMethod .getMethod();
               SecurityToken annotation = method.getAnnotation(SecurityToken.class);
               duplicateAvoidLOG.info("method infos,[method:" + method.getName()  + "]");
               if (annotation != null) {
                 //需要验证token
                   boolean needValidateToken = annotation.validateToken();
                   if(needValidateToken){
                       if(isRepeatSubmit(request)){
                           duplicateAvoidLOG.error("please don't repeat submit,[client:" + getRemoteHost(request) + ",url:"
                                    + request.getServletPath() + "]");
                           request.getSession().setAttribute(TOKEN_ERROR_CODE, "please don't repeat submit");
                           String fuction = annotation.ajaxFailCallBack();
                           String responStr = "{"duplicate":"true","callback":""+fuction+""}";
                           try {
                            response.getOutputStream().write(responStr.getBytes());
                            
                            response.getOutputStream().flush();
                            response.getOutputStream().close();
                        } catch (IOException e) {
                            duplicateAvoidLOG.error("repeat submit ,[client:" + getRemoteHost(request) + ",url:"
                                    + request.getServletPath() + "]");
                            e.printStackTrace();
                        }
                           return false;
                       }
                        request.getSession(false).removeAttribute(DUPLICATEAVOID_TOKEN);
                   }
                    //需要保存token,先产生token 保存到response的cookie中，服务器端保存在业务方法调用后保存
                   boolean needSaveToken = annotation.generateToken();
                   if (needSaveToken) {
                       String token = UUID.randomUUID().toString();
                       Cookie tokenCookie = new Cookie(PAGE_DUPLICATEAVOID_TOKEN, token);
                       tokenCookie.setMaxAge(expressTime);
                       tokenCookie.setPath("/");
                       response.addCookie(tokenCookie);
//                       response.addHeader(PAGE_DUPLICATEAVOID_TOKEN, token);
                       threadtoken.set(token);
                   }
            }
        }
        return true;
    }
    
    @Override
    public void postHandle(HttpServletRequest request,
            HttpServletResponse response, Object handler,
            ModelAndView modelAndView) throws Exception {
             duplicateAvoidLOG.info("DuplicateAvoidSubmitInterceptor postHandle,[client:" + getRemoteHost(request) + ",url:"
                 + request.getServletPath() + "]"+",token ="+ threadtoken.get());
        if (handler instanceof HandlerMethod) {
               HandlerMethod handlerMethod = (HandlerMethod) handler;
               Method method = handlerMethod .getMethod();
               SecurityToken annotation = method.getAnnotation(SecurityToken.class);
               duplicateAvoidLOG.info("method infos,[method:" + method.getName()  + "]");
               if (annotation != null) {
                    //保存token，到服务器的session中
                   boolean needSaveToken = annotation.generateToken();
                   if (needSaveToken) {
                       String token = threadtoken.get();
                       threadtoken.set("");
                       if (!StringUtils.isEmpty(token)) {                        
                           request.getSession().setAttribute(DUPLICATEAVOID_TOKEN, token);
                       }
                   }
            }
        }
    }


    private boolean isRepeatSubmit(HttpServletRequest request){
        
        String serverToken = (String) request.getSession(false).getAttribute(DUPLICATEAVOID_TOKEN);
        Cookie cookies[]=request.getCookies();
        Cookie tokenCookie=null; 
        String clinetToken = null;
        for (int i = 0; i < cookies.length; i++) {
            tokenCookie = cookies[i];
            if(PAGE_DUPLICATEAVOID_TOKEN.equals(tokenCookie.getName())){
                clinetToken = tokenCookie.getValue();
            }
        }
        if (StringUtils.isEmpty(clinetToken)) {
             clinetToken = request.getParameter(PAGE_DUPLICATEAVOID_TOKEN);
        }
        duplicateAvoidLOG.info("isRepeatSubmit ,[serverToken:" + serverToken + ",clinetToken:"
                + clinetToken + "]");
        if (StringUtils.isEmpty(serverToken) || StringUtils.isEmpty(clinetToken)) {
            return true;
        }
        if (!serverToken.equals(clinetToken)) {
            return true;
        }

        return false;
    }
    
    private String getRemoteHost(HttpServletRequest request){
        String ip = request.getHeader("x-forwarded-for");
        if(ip == null || ip.length() == 0 || "unknown".equalsIgnoreCase(ip)){
            ip = request.getHeader("Proxy-Client-IP");
        }
        if(ip == null || ip.length() == 0 || "unknown".equalsIgnoreCase(ip)){
            ip = request.getHeader("WL-Proxy-Client-IP");
        }
        if(ip == null || ip.length() == 0 || "unknown".equalsIgnoreCase(ip)){
            ip = request.getRemoteAddr();
        }
        return ip.equals("0:0:0:0:0:0:0:1")?"127.0.0.1":ip;
    }
    
}

SecurityToken.java

import java.lang.annotation.ElementType;
import java.lang.annotation.Retention;
import java.lang.annotation.RetentionPolicy;
import java.lang.annotation.Target;

import org.springframework.beans.factory.annotation.Required;

/**
 * <p>
 * 防止重复提交注解，用于方法上<br/>
 * 在control方法上，设置needSaveToken()为true，此时拦截器会在Session中保存一个token<br/>
 * 在control方法上，设置needValidateToken()为true，此时拦截器会在Session中验证token,并且删除token<br/>
 * 需要防止重复提交的页面中需要添加<br/>
 * </p>
 *
 */
@Target(ElementType.METHOD)
@Retention(RetentionPolicy.RUNTIME)
public @interface SecurityToken {
    boolean generateToken() default false;
    boolean validateToken() default false;
    //ajax请求如果重复提交后默认的JS回调方法
    String  ajaxFailCallBack() default "HandleTokenFail";
}

使用方法：

在跳转到需要防止重复提交的页面的controller上加注解来generateToken, 然后在业务方法的controller上加入注解validateToken（如果此方法跳转(或者ajax)执行完后下面的页面还要继续防重复可以在此方法上再加generateToken）