关于SpringBoot——防止sql注入，xss攻击，cros恶意访问

一.sql注入

sql注入：把SQL命令插入到Web表单递交或输入域名或页面请求的查询字符串，最终达到欺骗服务器执行恶意的SQL命令。

解决方法：

（1）无论是直接使用数据库还是使用如mybatis组件，使用sql的预编译，不要用拼接字符串；

（2）后台过滤检测：使用正则表达式过滤传入的参数**；**.字符串过滤；

（4）前端检测sql常见关键字，如or and drop之类的。

测试：

1、sql直接拼接，访问：http://localhost:8180/webapp2/testSql1?userName=1&passWord=1 or 1=1

实际执行sql：select user_name,pass_word from cas_user where user_name= '1' and pass_word=1 INVALID 1=1

结果：输入错误信息也能查询。

 

2、sql预编译（其他mybais组件类似），访问：http://localhost:8180/webapp2/testSql2?userName=1&passWord=1 or 1=1

实际执行sql：select user_name,pass_word from cas_user where user_name= '1' and pass_word= '1 INVALID 1=1'

 二种不同的sql写法：

 

3、代码中增加了过滤器检测表单输入后，sql关键字段会被过滤掉；访问：http://localhost:8180/webapp2/testSql2?userName=1&passWord=1 or 1=1

结果：非法输入被过滤器过滤掉了（或者替换了）。

 

二.xss攻击

xss攻击：其原理是攻击者向有XSS漏洞的网站中输入(传入)恶意的HTML代码，当其它用户浏览该网站时，这段HTML代码会自动执行，从而达到攻击的目的。

如，盗取用户Cookie、破坏页面结构、重定向到其它网站等。

解决方法：对用户输入的表单信息进行检测过滤。

测试：访问：http://localhost:8180/webapp2/testXss?userName=1&passWord=。

结果：非法输入被过滤器过滤掉了。

 

三.csrf/cros

CSRF - Cross-Site Request Forgery - 跨站请求伪造:

攻击可以在受害者毫不知情的情况下以受害者名义伪造请求发送给受攻击站点，从而在未授权的情况下执行在权限保护之下的操作，

CORS - Cross Origin Resourse-Sharing - 跨站资源共享，恶意访问内网敏感资源。

解决方法：

有效的解决办法是通过多种条件屏蔽掉非法的请求，例如HTTP头、参数等：

1.不信任未经身份验证的跨域请求，应该首先验证Session ID或者Cookie。

2.对于请求方来说验证接收的数据有效性，服务方仅暴露最少最必须的功能。

3.通过多种条件屏蔽掉非法的请求，例如HTTP头、参数等。

服务端代码跨域设置，设置了nginx转发，也可设置在nginx中。

四.防止大规模的恶意请求

niginx反向代理可以配置请求频率，对ip做限制。nginx可以很方便地做访问控制，特别是一些偶发性的大量恶意请求，需要屏蔽处理。

1、屏蔽ip地址

location /someapi/ {
allow ip;  #特定接口只开放给某个ip调用
deny all;
}

location /somepage/ {
deny ip;   #屏蔽某个ip访问（iptables可以拒绝某个ip连接）
allow all;
}

2、屏蔽user-agent

if ($http_user_agent = Mozilla/5.0 ) { return 403; }   #有些请求头很明显不是用户浏览器

分析nginx日志，找出恶意ip或user-agent

cat /var/log/nginx/access.log | awk -F\" '{A[$(NF-1)]++}END{for(k in A)print A[k],k}' | sort -n |tail
122 58.144.7.66
337 106.91.201.75
2270 122.200.77.170  #显然这个ip不正常，而且这不是nginx所知道的真实ip，而是$http_x_forwarded_for变量

3、屏蔽代理ip

有两种情形会需要屏蔽代理ip：一是代理ip访问，二是负载均衡（real-ip请求负载均衡服务器，再代理给后端server）。

vi /etc/nginx/badproxy.rules
map $http_x_forwarded_for $badproxy {
        default 0;
        ~*122.200.77.170  1;  #建立映射
}
vi /etc/nginx/nginx.conf
http {
include /etc/nginx/badproxy.rules  #这个要在server配置之前
server {
    location /somepage/ {
        if ( $badproxy ) { return 403; }
    }
}
}

 

五.代码示例

1、第一步

创建XssAndSqlHttpServletRequestWrapper包装器，这是实现XSS过滤的关键，在其内重写了getParameter，getParameterValues，getHeader等方法，对http请求内的参数进行了过滤。

package com.demo.common;

import java.io.BufferedReader;
import java.io.ByteArrayInputStream;
import java.io.IOException;
import java.io.InputStreamReader;
import java.util.Enumeration;
import java.util.HashMap;
import java.util.Map;
import java.util.Set;
import java.util.Vector;
import java.util.regex.Pattern;

import javax.servlet.ReadListener;
import javax.servlet.ServletInputStream;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletRequestWrapper;

import org.springframework.util.StreamUtils;

import com.sgcc.uap.utils.stream.StreamUtil;

public class XssAndSqlHttpServletRequestWrapper extends HttpServletRequestWrapper {

    HttpServletRequest orgRequest = null;
    private Map<String, String[]> parameterMap;
    private final byte[] body; //用于保存读取body中数据

    public XssAndSqlHttpServletRequestWrapper(HttpServletRequest request) throws IOException{
        super(request);
        orgRequest = request;
        parameterMap = request.getParameterMap();
        body = StreamUtils.copyToByteArray(request.getInputStream());
    }

    // 重写几个HttpServletRequestWrapper中的方法
    /**
     * 获取所有参数名
     *
     * @return 返回所有参数名
     */
    @Override
    public Enumeration<String> getParameterNames() {
        Vector<String> vector = new Vector<String>(parameterMap.keySet());
        return vector.elements();
    }

    /**
     * 覆盖getParameter方法，将参数名和参数值都做xss & sql过滤。<br/>
     * 如果需要获得原始的值，则通过super.getParameterValues(name)来获取<br/>
     * getParameterNames,getParameterValues和getParameterMap也可能需要覆盖
     */
    @Override
    public String getParameter(String name) {
        String[] results = parameterMap.get(name);
        if (results == null || results.length <= 0)
            return null;
        else {
            String value = results[0];
            if (value != null) {
                value = xssEncode(value);
            }
            return value;
        }
    }

    /**
     * 获取指定参数名的所有值的数组，如：checkbox的所有数据 接收数组变量 ，如checkobx类型
     */
    @Override
    public String[] getParameterValues(String name) {
        String[] results = parameterMap.get(name);
        if (results == null || results.length <= 0)
            return null;
        else {
            int length = results.length;
            for (int i = 0; i < length; i++) {
                results[i] = xssEncode(results[i]);
            }
            return results;
        }
    }

    /**
     * 覆盖getHeader方法，将参数名和参数值都做xss & sql过滤。<br/>
     * 如果需要获得原始的值，则通过super.getHeaders(name)来获取<br/>
     * getHeaderNames 也可能需要覆盖
     */
    @Override
    public String getHeader(String name) {

        String value = super.getHeader(xssEncode(name));
        if (value != null) {
            value = xssEncode(value);
        }
        return value;
    }

    /**
     * 将容易引起xss & sql漏洞的半角字符直接替换成全角字符
     * 
     * @param s
     * @return
     */
    private static String xssEncode(String s) {
        if (s == null || s.isEmpty()) {
            return s;
        } else {
            s = stripXSSAndSql(s);
        }
        StringBuilder sb = new StringBuilder(s.length() + 16);
        for (int i = 0; i < s.length(); i++) {
            char c = s.charAt(i);
            switch (c) {
            case '>':
                sb.append("＞");// 转义大于号
                break;
            case '<':
                sb.append("＜");// 转义小于号
                break;
            // case '\'':
            // sb.append("＇");// 转义单引号
            // break;
            // case '\"':
            // sb.append("＂");// 转义双引号
            // break;
            case '&':
                sb.append("＆");// 转义&
                break;
            case '#':
                sb.append("＃");// 转义#
                break;
            default:
                sb.append(c);
                break;
            }
        }
        return sb.toString();
    }

    /**
     * 获取最原始的request
     * 
     * @return
     */
    public HttpServletRequest getOrgRequest() {
        return orgRequest;
    }

    /**
     * 获取最原始的request的静态方法
     * 
     * @return
     */
    public static HttpServletRequest getOrgRequest(HttpServletRequest req) {
        if (req instanceof XssAndSqlHttpServletRequestWrapper) {
            return ((XssAndSqlHttpServletRequestWrapper) req).getOrgRequest();
        }
        return req;
    }

    /**
     * 
     * 防止xss跨脚本攻击（替换，根据实际情况调整）
     */

    public static String stripXSSAndSql(String value) {
        if (value != null) {
            // NOTE: It's highly recommended to use the ESAPI library and
            // uncomment the following line to
            // avoid encoded attacks.
            // value = ESAPI.encoder().canonicalize(value);
            // Avoid null characters
            /** value = value.replaceAll("", ""); ***/
            // Avoid anything between script tags
            Pattern scriptPattern = Pattern.compile(
                    "<[\r\n| | ]*script[\r\n| | ]*>(.*?)</[\r\n| | ]*script[\r\n| | ]*>", Pattern.CASE_INSENSITIVE);
            value = scriptPattern.matcher(value).replaceAll("");
            // Avoid anything in a
            // src="http://www.yihaomen.com/article/java/..." type of
            // e-xpression
            scriptPattern = Pattern.compile("src[\r\n| | ]*=[\r\n| | ]*[\\\"|\\\'](.*?)[\\\"|\\\']",
                    Pattern.CASE_INSENSITIVE | Pattern.MULTILINE | Pattern.DOTALL);
            value = scriptPattern.matcher(value).replaceAll("");
            // Remove any lonesome </script> tag
            scriptPattern = Pattern.compile("</[\r\n| | ]*script[\r\n| | ]*>", Pattern.CASE_INSENSITIVE);
            value = scriptPattern.matcher(value).replaceAll("");
            // Remove any lonesome <script ...> tag
            scriptPattern = Pattern.compile("<[\r\n| | ]*script(.*?)>",
                    Pattern.CASE_INSENSITIVE | Pattern.MULTILINE | Pattern.DOTALL);
            value = scriptPattern.matcher(value).replaceAll("");
            // Avoid eval(...) expressions
            scriptPattern = Pattern.compile("eval\\((.*?)\\)",
                    Pattern.CASE_INSENSITIVE | Pattern.MULTILINE | Pattern.DOTALL);
            value = scriptPattern.matcher(value).replaceAll("");
            // Avoid e-xpression(...) expressions
            scriptPattern = Pattern.compile("e-xpression\\((.*?)\\)",
                    Pattern.CASE_INSENSITIVE | Pattern.MULTILINE | Pattern.DOTALL);
            value = scriptPattern.matcher(value).replaceAll("");
            // Avoid javascript:... expressions
            scriptPattern = Pattern.compile("javascript[\r\n| | ]*:[\r\n| | ]*", Pattern.CASE_INSENSITIVE);
            value = scriptPattern.matcher(value).replaceAll("");
            // Avoid vbscript:... expressions
            scriptPattern = Pattern.compile("vbscript[\r\n| | ]*:[\r\n| | ]*", Pattern.CASE_INSENSITIVE);
            value = scriptPattern.matcher(value).replaceAll("");
            // Avoid onload= expressions
            scriptPattern = Pattern.compile("onload(.*?)=",
                    Pattern.CASE_INSENSITIVE | Pattern.MULTILINE | Pattern.DOTALL);
            value = scriptPattern.matcher(value).replaceAll("");
        }
        return value;
    }

    public static boolean checkXSSAndSql(String value) {
        boolean flag = false;
        if (value != null) {
            // NOTE: It's highly recommended to use the ESAPI library and
            // uncomment the following line to
            // avoid encoded attacks.
            // value = ESAPI.encoder().canonicalize(value);
            // Avoid null characters
            /** value = value.replaceAll("", ""); ***/
            // Avoid anything between script tags
            Pattern scriptPattern = Pattern.compile(
                    "<[\r\n| | ]*script[\r\n| | ]*>(.*?)</[\r\n| | ]*script[\r\n| | ]*>", Pattern.CASE_INSENSITIVE);
            flag = scriptPattern.matcher(value).find();
            if (flag) {
                return flag;
            }
            // Avoid anything in a
            // src="http://www.yihaomen.com/article/java/..." type of
            // e-xpression
            scriptPattern = Pattern.compile("src[\r\n| | ]*=[\r\n| | ]*[\\\"|\\\'](.*?)[\\\"|\\\']",
                    Pattern.CASE_INSENSITIVE | Pattern.MULTILINE | Pattern.DOTALL);
            flag = scriptPattern.matcher(value).find();
            if (flag) {
                return flag;
            }
            // Remove any lonesome </script> tag
            scriptPattern = Pattern.compile("</[\r\n| | ]*script[\r\n| | ]*>", Pattern.CASE_INSENSITIVE);
            flag = scriptPattern.matcher(value).find();
            if (flag) {
                return flag;
            }
            // Remove any lonesome <script ...> tag
            scriptPattern = Pattern.compile("<[\r\n| | ]*script(.*?)>",
                    Pattern.CASE_INSENSITIVE | Pattern.MULTILINE | Pattern.DOTALL);
            flag = scriptPattern.matcher(value).find();
            if (flag) {
                return flag;
            }
            // Avoid eval(...) expressions
            scriptPattern = Pattern.compile("eval\\((.*?)\\)",
                    Pattern.CASE_INSENSITIVE | Pattern.MULTILINE | Pattern.DOTALL);
            flag = scriptPattern.matcher(value).find();
            if (flag) {
                return flag;
            }
            // Avoid e-xpression(...) expressions
            scriptPattern = Pattern.compile("e-xpression\\((.*?)\\)",
                    Pattern.CASE_INSENSITIVE | Pattern.MULTILINE | Pattern.DOTALL);
            flag = scriptPattern.matcher(value).find();
            if (flag) {
                return flag;
            }
            // Avoid javascript:... expressions
            scriptPattern = Pattern.compile("javascript[\r\n| | ]*:[\r\n| | ]*", Pattern.CASE_INSENSITIVE);
            flag = scriptPattern.matcher(value).find();
            if (flag) {
                return flag;
            }
            // Avoid vbscript:... expressions
            scriptPattern = Pattern.compile("vbscript[\r\n| | ]*:[\r\n| | ]*", Pattern.CASE_INSENSITIVE);
            flag = scriptPattern.matcher(value).find();
            if (flag) {
                return flag;
            }
            // Avoid onload= expressions
            scriptPattern = Pattern.compile("onload(.*?)=",
                    Pattern.CASE_INSENSITIVE | Pattern.MULTILINE | Pattern.DOTALL);
            flag = scriptPattern.matcher(value).find();
            if (flag) {
                return flag;
            }
           scriptPattern = Pattern.compile("\\b(and|exec|insert|select|drop|grant|alter|delete|update|count|chr|mid|master|truncate|char|declare|or)\\b|(\\*|;|\\+|'|%)",
                    Pattern.CASE_INSENSITIVE | Pattern.MULTILINE | Pattern.DOTALL);
            flag = scriptPattern.matcher(value).find();
            if (flag) {
                return flag;
            }
        }
        return flag;
    }

    public final boolean checkParameter() {
        Map<String, String[]> submitParams = new HashMap(parameterMap);
        Set<String> submitNames = submitParams.keySet();
        for (String submitName : submitNames) {
            Object submitValues = submitParams.get(submitName);
            if ((submitValues instanceof String)) {
                if (checkXSSAndSql((String) submitValues)) {
                    return true;
                }
            } else if ((submitValues instanceof String[])) {
                for (String submitValue : (String[])submitValues){
                    if (checkXSSAndSql(submitValue)) {
                        return true;
                    }
                }
            }
        }
        return false;
    }
    
    @Override    
    public BufferedReader getReader() throws IOException {    
        return new BufferedReader(new InputStreamReader(getInputStream()));    
    }    
    
    @Override    
    public ServletInputStream getInputStream() throws IOException {    
        final ByteArrayInputStream bais = new ByteArrayInputStream(body);    
        return new ServletInputStream() {    
    
            @Override    
            public int read() throws IOException {    
                return bais.read();    
            }  

            @Override  
            public boolean isFinished() {  
                // TODO Auto-generated method stub  
                return false;  
            }  

            @Override  
            public boolean isReady() {  
                // TODO Auto-generated method stub  
                return false;  
            }  

            @Override  
            public void setReadListener(ReadListener arg0) {  
                // TODO Auto-generated method stub  
                  
            }    
        };    
    }

}

 

2、第二步

写过滤器：

package com.demo.common;

import java.io.BufferedReader;
import java.io.IOException;
import java.io.PrintWriter;

import javax.servlet.Filter;
import javax.servlet.FilterChain;
import javax.servlet.FilterConfig;
import javax.servlet.ServletException;
import javax.servlet.ServletRequest;
import javax.servlet.ServletResponse;
import javax.servlet.http.HttpServletRequest;

import org.apache.commons.lang3.StringUtils;

public class XssAndSqlFilter implements Filter {

    @Override
    public void destroy() {
        // TODO Auto-generated method stub

    }

    @Override
    public void doFilter(ServletRequest request, ServletResponse response, FilterChain chain)
            throws IOException, ServletException {
        String method = "GET";
        String param = "";
        XssAndSqlHttpServletRequestWrapper xssRequest = null;
        if (request instanceof HttpServletRequest) {
            method = ((HttpServletRequest) request).getMethod();
            xssRequest = new XssAndSqlHttpServletRequestWrapper((HttpServletRequest) request);
        }
        if ("POST".equalsIgnoreCase(method)) {
            param = this.getBodyString(xssRequest.getReader());
            if(StringUtils.isNotBlank(param)){
                if(xssRequest.checkXSSAndSql(param)){
                    response.setCharacterEncoding("UTF-8");
                    response.setContentType("application/json;charset=UTF-8");
                    PrintWriter out = response.getWriter();
                    out.write(JSONObject.toJSONString("您所访问的页面请求中有违反安全规则元素存在，拒绝访问!"));
                    return;
                }
            }
        }
        if (xssRequest.checkParameter()) {
            response.setCharacterEncoding("UTF-8");
            response.setContentType("application/json;charset=UTF-8");
            PrintWriter out = response.getWriter();
            out.write(JSONObject.toJSONString("您所访问的页面请求中有违反安全规则元素存在，拒绝访问!"));
            return;
        }
        chain.doFilter(xssRequest, response);
    }

    @Override
    public void init(FilterConfig arg0) throws ServletException {
        // TODO Auto-generated method stub

    }

    // 获取request请求body中参数
    public static String getBodyString(BufferedReader br) {
        String inputLine;
        String str = "";
        try {
            while ((inputLine = br.readLine()) != null) {
                str += inputLine;
            }
            br.close();
        } catch (IOException e) {
            System.out.println("IOException: " + e);
        }
        return str;

    }

}

 

3、第三步

注册过滤器XssAndSqlFilter。

package com.demo.config;

import java.util.Map;

import org.springframework.boot.web.servlet.FilterRegistrationBean;
import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;

import com.beust.jcommander.internal.Maps;
import com.swireproperties.cams.common.filter.XssAndSqlFilter;

/**
 * web配置
 */
@Configuration
public class WebConfig {

    @Bean
    public FilterRegistrationBean xssFilterRegistrationBean() {
        FilterRegistrationBean filterRegistrationBean = new FilterRegistrationBean();
        filterRegistrationBean.setFilter(new XssAndSqlFilter());
        filterRegistrationBean.setOrder(1);
        filterRegistrationBean.setEnabled(true);
        filterRegistrationBean.addUrlPatterns("/*");
        Map<String, String> initParameters = Maps.newHashMap();
        initParameters.put("excludes", "/favicon.ico,/img/*,/js/*,/css/*");
        initParameters.put("isIncludeRichText", "true");
        filterRegistrationBean.setInitParameters(initParameters);
        return filterRegistrationBean;
    }

}

备注：

-excludes用于配置不需要参数过滤的请求url。

-isIncludeRichText默认为true，主要用于设置富文本内容是否需要过滤。