前言
刚写代码不就,还不能做深层次安全措施,今天研究了一下基本的防止接口多次恶意请求的方法。
思路
1:设置同一IP,一个时间段内允许访问的最大次数
2:记录所有IP单位时间内访问的次数
3:将所有被限制IP存到存储器
4:通过IP过滤访问请求
该demo只有后台Java代码,没有前端
代码
首先是获取IP的工具类
public class Ipsettings { public static String getRemoteHost(HttpServletRequest request) { String ipAddress = null; //ipAddress = request.getRemoteAddr(); ipAddress = request.getHeader("x-forwarded-for"); if(ipAddress == null || ipAddress.length() == 0 || "unknown".equalsIgnoreCase(ipAddress)) { ipAddress = request.getHeader("Proxy-Client-IP"); } if(ipAddress == null || ipAddress.length() == 0 || "unknown".equalsIgnoreCase(ipAddress)) { ipAddress = request.getHeader("WL-Proxy-Client-IP"); } if(ipAddress == null || ipAddress.length() == 0 || "unknown".equalsIgnoreCase(ipAddress)) { ipAddress = request.getRemoteAddr(); if(ipAddress.equals("127.0.0.1")){ //根据网卡取本机配置的IP InetAddress inet=null; try { inet = InetAddress.getLocalHost(); } catch (UnknownHostException e) { e.printStackTrace(); } ipAddress= inet.getHostAddress(); } } //对于通过多个代理的情况,第一个IP为客户端真实IP,多个IP按照','分割 if(ipAddress!=null && ipAddress.length()>15){ //"***.***.***.***".length() = 15 if(ipAddress.indexOf(",")>0){ ipAddress = ipAddress.substring(0,ipAddress.indexOf(",")); } } return ipAddress; } }
其次是监听器以及IP存储器
import java.util.HashMap; import java.util.Map; import javax.servlet.ServletContext; import javax.servlet.ServletContextEvent; import javax.servlet.ServletContextListener; import javax.servlet.annotation.WebListener; import org.slf4j.Logger; import org.slf4j.LoggerFactory; @WebListener public class MyApplicationListener implements ServletContextListener { private Logger logger = LoggerFactory.getLogger(MyApplicationListener.class); @Override public void contextInitialized(ServletContextEvent sce) { logger.info("liting: contextInitialized"); System.err.println("初始化成功"); ServletContext context = sce.getServletContext(); // IP存储器 Map<String, Long[]> ipMap = new HashMap<String, Long[]>(); context.setAttribute("ipMap", ipMap); // 限制IP存储器:存储被限制的IP信息 Map<String, Long> limitedIpMap = new HashMap<String, Long>(); context.setAttribute("limitedIpMap", limitedIpMap); logger.info("ipmap:"+ipMap.toString()+";limitedIpMap:"+limitedIpMap.toString()+"初始化成功。。。。。"); } @Override public void contextDestroyed(ServletContextEvent sce) { // TODO Auto-generated method stub } }
最后是具体规则设置
import java.io.IOException; import java.util.Iterator; import java.util.Map; import java.util.Set; import javax.servlet.Filter; import javax.servlet.FilterChain; import javax.servlet.FilterConfig; import javax.servlet.ServletContext; import javax.servlet.ServletException; import javax.servlet.ServletRequest; import javax.servlet.ServletResponse; import javax.servlet.annotation.WebFilter; import javax.servlet.http.HttpServletRequest; import javax.servlet.http.HttpServletResponse; @WebFilter(urlPatterns="/*") public class IpFilter implements Filter{ /** * 默认限制时间(单位:ms) */ private static final long LIMITED_TIME_MILLIS = 5 * 2 * 1000; /** * 用户连续访问最高阀值,超过该值则认定为恶意操作的IP,进行限制 */ private static final int LIMIT_NUMBER = 2; /** * 用户访问最小安全时间,在该时间内如果访问次数大于阀值,则记录为恶意IP,否则视为正常访问 */ private static final int MIN_SAFE_TIME = 5000; private FilterConfig config; @Override public void init(FilterConfig filterConfig) throws ServletException { this.config = filterConfig; //设置属性filterConfig } /* (non-Javadoc) * @see javax.servlet.Filter#doFilter(javax.servlet.ServletRequest, javax.servlet.ServletResponse, javax.servlet.FilterChain) */ @SuppressWarnings("unchecked") @Override public void doFilter(ServletRequest servletRequest, ServletResponse servletResponse, FilterChain chain) throws IOException, ServletException { HttpServletRequest request = (HttpServletRequest) servletRequest; HttpServletResponse response = (HttpServletResponse) servletResponse; ServletContext context = config.getServletContext(); // 获取限制IP存储器:存储被限制的IP信息 Map<String, Long> limitedIpMap = (Map<String, Long>) context.getAttribute("limitedIpMap"); // 过滤受限的IP filterLimitedIpMap(limitedIpMap); // 获取用户IP String ip = Ipsettings.getRemoteHost(request); System.err.println("ip:"+ip); //以下是处理限制IP的规则,可以自己写 // 判断是否是被限制的IP,如果是则跳到异常页面 if (isLimitedIP(limitedIpMap, ip)) { long limitedTime = limitedIpMap.get(ip) - System.currentTimeMillis(); // 剩余限制时间(用为从毫秒到秒转化的一定会存在些许误差,但基本可以忽略不计) request.setAttribute("remainingTime", ((limitedTime / 1000) + (limitedTime % 1000 > 0 ? 1 : 0))); //request.getRequestDispatcher("/error/overLimitIP").forward(request, response); System.err.println("ip访问过于频繁:"+ip); return; } // 获取IP存储器 Map<String, Long[]> ipMap = (Map<String, Long[]>) context.getAttribute("ipMap"); // 判断存储器中是否存在当前IP,如果没有则为初次访问,初始化该ip // 如果存在当前ip,则验证当前ip的访问次数 // 如果大于限制阀值,判断达到阀值的时间,如果不大于[用户访问最小安全时间]则视为恶意访问,跳转到异常页面 if (ipMap.containsKey(ip)) { Long[] ipInfo = ipMap.get(ip); ipInfo[0] = ipInfo[0] + 1; System.out.println("当前第[" + (ipInfo[0]) + "]次访问"); if (ipInfo[0] > LIMIT_NUMBER) { Long ipAccessTime = ipInfo[1]; Long currentTimeMillis = System.currentTimeMillis(); if (currentTimeMillis - ipAccessTime <= MIN_SAFE_TIME) { limitedIpMap.put(ip, currentTimeMillis + LIMITED_TIME_MILLIS); request.setAttribute("remainingTime", LIMITED_TIME_MILLIS); System.err.println("ip访问过于频繁:"+ip); request.getRequestDispatcher("/error/overLimitIP").forward(request, response); return; } else { initIpVisitsNumber(ipMap, ip); } } } else { initIpVisitsNumber(ipMap, ip); System.out.println("您首次访问该网站"); } context.setAttribute("ipMap", ipMap); chain.doFilter(request, response); } @Override public void destroy() { // TODO Auto-generated method stub } /** * @Description 过滤受限的IP,剔除已经到期的限制IP * @param limitedIpMap */ private void filterLimitedIpMap(Map&<span style="color:transparent">本文来源gaodai#ma#com搞*!代#%^码$网!</span>lt;String, Long> limitedIpMap) { if (limitedIpMap == null) { return; } Set<String> keys = limitedIpMap.keySet(); Iterator<String> keyIt = keys.iterator(); long currentTimeMillis = System.currentTimeMillis(); while (keyIt.hasNext()) { long expireTimeMillis = limitedIpMap.get(keyIt.next()); if (expireTimeMillis <= currentTimeMillis) { keyIt.remove(); } } } /** * @Description 是否是被限制的IP * @param limitedIpMap * @param ip * @return true : 被限制 | false : 正常 */ private boolean isLimitedIP(Map<String, Long> limitedIpMap, String ip) { if (limitedIpMap == null || ip == null) { // 没有被限制 return false; } Set<String> keys = limitedIpMap.keySet(); Iterator<String> keyIt = keys.iterator(); while (keyIt.hasNext()) { String key = keyIt.next(); if (key.equals(ip)) { // 被限制的IP return true; } } return false; } /** * 初始化用户访问次数和访问时间 * * @param ipMap * @param ip */ private void initIpVisitsNumber(Map<String, Long[]> ipMap, String ip) { Long[] ipInfo = new Long[2]; ipInfo[0] = 0L;// 访问次数 ipInfo[1] = System.currentTimeMillis();// 初次访问时间 ipMap.put(ip, ipInfo); } }