IP白名单鉴权

参考地址：https://www.cnblogs.com/shinubi/p/6723003.html

开发过程中，当给第三方提供接口的时候，总会涉及到对ip鉴权，防止其他用户非法访问。而要完成以上功能，需要做到三步：
1. 获取客户端真实ip
2. 设置访问白名单
3. 过滤非法ip

获取客户端真实IP，已在上一篇做了介绍，这里不在赘述，以下主要介绍后两步。

获取白名单

以下白名单工具类支持单个ip、包含一个通配符“*” 和IP范围设置

import java.util.ArrayList;
import java.util.HashSet;
import java.util.List;
import java.util.Set;
import java.util.regex.Pattern;

/**
 * @ClassName:IPWhiteUtil
 * @Function: IP 白名单.
 * @Reason:关于IP白名单相关.
 * @Date: 2018-5-8
 * @version
 */
public class IPWhiteUtil {
    // IP的正则
    private static Pattern pattern = Pattern
            .compile("(1\\d{1,2}|2[0-4]\\d|25[0-5]|\\d{1,2})\\."
                    + "(1\\d{1,2}|2[0-4]\\d|25[0-5]|\\d{1,2})\\."
                    + "(1\\d{1,2}|2[0-4]\\d|25[0-5]|\\d{1,2})\\."
                    + "(1\\d{1,2}|2[0-4]\\d|25[0-5]|\\d{1,2})");

    /**
     * 
     * getAvaliIpList:(根据IP白名单设置获取可用的IP列表).
     * 
     * @date 2018-5-8 
     * @param ipConfig
     * @return
     */

    private static Set<String> getAvaliIpList(String allowIp) {

        Set<String> ipList = new HashSet<String>();
        for (String allow : allowIp.replaceAll("\\s", "").split(";")) {
            if (allow.indexOf("*") > -1) {
                String[] ips = allow.split("\\.");
                String[] from = new String[] { "0", "0", "0", "0" };
                String[] end = new String[] { "255", "255", "255", "255" };
                List<String> tem = new ArrayList<String>();
                for (int i = 0; i < ips.length; i++)
                    if (ips[i].indexOf("*") > -1) {
                        tem = complete(ips[i]);
                        from[i] = null;
                        end[i] = null;
                    } else {
                        from[i] = ips[i];
                        end[i] = ips[i];
                    }

                StringBuffer fromIP = new StringBuffer();
                StringBuffer endIP = new StringBuffer();
                for (int i = 0; i < 4; i++)
                    if (from[i] != null) {
                        fromIP.append(from[i]).append(".");
                        endIP.append(end[i]).append(".");
                    } else {
                        fromIP.append("[*].");
                        endIP.append("[*].");
                    }
                fromIP.deleteCharAt(fromIP.length() - 1);
                endIP.deleteCharAt(endIP.length() - 1);

                for (String s : tem) {
                    String ip = fromIP.toString().replace("[*]",
                            s.split(";")[0])
                            + "-"
                            + endIP.toString().replace("[*]", s.split(";")[1]);
                    if (validate(ip)) {
                        ipList.add(ip);
                    }
                }
            } else {
                if (validate(allow)) {
                    ipList.add(allow);
                }
            }

        }
        return ipList;
    }

    /**
     * 对单个IP节点进行范围限定
     * 
     * @param arg
     * @return 返回限定后的IP范围，格式为List[10;19, 100;199]
     */
    private static List<String> complete(String arg) {
        List<String> com = new ArrayList<String>();
        if (arg.length() == 1) {
            com.add("0;255");
        } else if (arg.length() == 2) {
            String s1 = complete(arg, 1);
            if (s1 != null)
                com.add(s1);
            String s2 = complete(arg, 2);
            if (s2 != null)
                com.add(s2);
        } else {
            String s1 = complete(arg, 1);
            if (s1 != null)
                com.add(s1);
        }
        return com;
    }

    private static String complete(String arg, int length) {
        String from = "";
        String end = "";
        if (length == 1) {
            from = arg.replace("*", "0");
            end = arg.replace("*", "9");
        } else {
            from = arg.replace("*", "00");
            end = arg.replace("*", "99");
        }
        if (Integer.valueOf(from) > 255)
            return null;
        if (Integer.valueOf(end) > 255)
            end = "255";
        return from + ";" + end;
    }

    /**
     * 在添加至白名单时进行格式校验
     * 
     * @param ip
     * @return
     */
    private static boolean validate(String ip) {
        for (String s : ip.split("-"))
            if (!pattern.matcher(s).matches()) {
                return false;
            }
        return true;
    }

    /**
     * 
     * checkLoginIP:(根据IP,及可用Ip列表来判断ip是否包含在白名单之中).
     * @date 2018-5-8 下午03:01:03
     * @param ip
     * @param ipList
     * @return
     */
    private static boolean checkLoginIP(String ip, Set<String> ipList) {
        if (ipList.isEmpty() || ipList.contains(ip))
            return true;
        else {
            for (String allow : ipList) {
                if (allow.indexOf("-") > -1) {
                    String[] from = allow.split("-")[0].split("\\.");
                    String[] end = allow.split("-")[1].split("\\.");
                    String[] tag = ip.split("\\.");

                    // 对IP从左到右进行逐段匹配
                    boolean check = true;
                    for (int i = 0; i < 4; i++) {
                        int s = Integer.valueOf(from[i]);
                        int t = Integer.valueOf(tag[i]);
                        int e = Integer.valueOf(end[i]);
                        if (!(s <= t && t <= e)) {
                            check = false;
                            break;
                        }
                    }
                    if (check) {
                        return true;
                    }
                }
            }
        }
        return false;
    }

    /**
     * 
     * checkLoginIP:(根据IP地址，及IP白名单设置规则判断IP是否包含在白名单).
     * @date 2018-5-8 
     * @param ip
     * @param ipWhiteConfig
     * @return
     */
    public static boolean checkLoginIP(String ip,String ipWhiteConfig){
        Set<String> ipList = getAvaliIpList(ipWhiteConfig);
        return checkLoginIP(ip, ipList);
    }

    public static void main(String[] args) {

        String ipWhilte = "192.168.1.1;" +                 //设置单个IP的白名单
                          "192.168.2.*;" +                 //设置ip通配符,对一个ip段进行匹配
                          "192.168.3.17-192.168.3.38";     //设置一个IP范围
        boolean flag = IPWhiteUtil.checkLoginIP("192.168.2.2",ipWhilte);
        boolean flag2 = IPWhiteUtil.checkLoginIP("192.168.1.2",ipWhilte);
        boolean flag3 = IPWhiteUtil.checkLoginIP("192.168.3.16",ipWhilte);
        boolean flag4 = IPWhiteUtil.checkLoginIP("192.168.3.19",ipWhilte);
        System.out.println(flag);  //true
        System.out.println(flag2);  //false
        System.out.println(flag3);  //false
        System.out.println(flag4);  //true
    }
}

通过spring MVC拦截器拦截IP

继承HandlerInterceptorAdapter类，并重写preHandle方法

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

import org.springframework.web.servlet.handler.HandlerInterceptorAdapter;

import com.neusoft.airline.scal.ota.util.IPWhiteUtil;
import com.neusoft.airline.scal.ota.util.OtaConfigUtil;

public class IPLimitInterceptor extends HandlerInterceptorAdapter{

    @Override
    public boolean preHandle(HttpServletRequest request, HttpServletResponse response, Object handler)
            throws Exception {
        String ip = getIpAddress(request);
        String whiteIPList = OtaConfigUtil.getOtaWhiteIP();
        if(IPWhiteUtil.checkLoginIP(ip, whiteIPList)) {
            return super.preHandle(request, response, handler);
        }
        throw new Exception("IP非法访问!");
    }

    private String getIpAddress(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.getHeader("HTTP_CLIENT_IP");
        }
        if (ip == null || ip.length() == 0 || "unknown".equalsIgnoreCase(ip)) {
            ip = request.getHeader("HTTP_X_FORWARDED_FOR");
        }
        if (ip == null || ip.length() == 0 || "unknown".equalsIgnoreCase(ip)) {
            ip = request.getRemoteAddr();
        }
        //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(ip!=null && ip.length()>15){ //"***.***.***.***".length() = 15    
            if(ip.indexOf(",")>0){    
                ip = ip.substring(0,ip.indexOf(","));    
            }    
        }    
        System.out.println("访问ip========="+ip);
        return ip;
    }
}

在springMVC配置文件中添加映射

<mvc:interceptors>
    <!-- IP鉴权拦截器 -->
    <mvc:interceptor>
        <mvc:mapping path="/**"/>
        <bean class="com.neusoft.airline.scal.ota.interceptor.IPLimitInterceptor"></bean>
    </mvc:interceptor>
</mvc:interceptors>