SpringBoot 防止XSS攻击和SQL攻击拦截器(Filter)

什么是SQL攻击、什么是XSS攻击

SQL 攻击:把SQL命令插入到Web表单并提交,欺骗服务器执行恶意的SQL命令。

XSS 攻击: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。

创建拦截器第一步：

创建XssAndSqlHttpServletRequestWrapper包装器，这是实现XSS和SQL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。

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;

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;
    }
    
    /**
     * 审查参数的具体方法
     * @param value
     * @return
     */
    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 οnlοad= 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;
    }

    /**
     * 检查参数方法
     * @return
     */
    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;
    }

    /**
     * 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 οnlοad= expressions
            scriptPattern = Pattern.compile("onload(.*?)=",
                    Pattern.CASE_INSENSITIVE | Pattern.MULTILINE | Pattern.DOTALL);
            value = scriptPattern.matcher(value).replaceAll("");
        }
        return value;
    }
    
    /**
     **application/x- www-form-urlencoded是Post请求默认的请求体内容类型，也是form表单默认的类型。
     * Servlet API规范中对该类型的请求内容提供了request.getParameter()方法来获取请求参数值。
     * 但当请求内容不是该类型时，需要调用request.getInputStream()或request.getReader()方法来获取请求内容值。
     */
    /**
     * 获取请求内容
     * @return
     * @throws IOException
     */
    @Override
    public BufferedReader getReader() throws IOException {
        return new BufferedReader(new InputStreamReader(getInputStream()));
    }

    /**
     * 返回请求内容字节流，多用于文件上传，
     * request.getReader()是对前者返回内容的封装，可以让调用者更方便字符内容的处理（不用自己先获取字节流再做字符流的转换操作）
     * @return
     * @throws IOException
     */
    @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

            }
        };
    }

}

创建拦截器第二步：

编写过滤器

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

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

import org.apache.commons.lang3.StringUtils;

import com.alibaba.fastjson.JSONObject;
import com.digipower.common.entity.Result;
import com.digipower.http.servlet.request.wrapper.XssAndSqlHttpServletRequestWrapper;

/**
 * 防止XSS 攻击和SQL注入攻击的Filter
 * @ClassName:  XssAndSqlFilter   
 * @Description:TODO(这里用一句话描述这个类的作用)   
 * @author:
 * @date:   2021年3月22日 下午2:29:12   
 *     
 * @Copyright: 2021 www.digipower.cn 
 * 注意：
 */
public class XssAndSqlFilter implements Filter {

	@Override
	public void doFilter(ServletRequest request, ServletResponse response, FilterChain chain)
			throws IOException, ServletException {
		 String method = "GET";//设置初始值
	        String param = "";
	        XssAndSqlHttpServletRequestWrapper xssRequest = null;
	        if (request instanceof HttpServletRequest) {//判断左边的对象是否是它右边对象的实例
	            method = ((HttpServletRequest) request).getMethod();//得到请求URL地址时使用的方法
	            xssRequest = new XssAndSqlHttpServletRequestWrapper((HttpServletRequest) request);//创建对象
	        }
	        if ("POST".equalsIgnoreCase(method)) {//判断是否为post
	            param = this.getBodyString(xssRequest.getReader());//获取参数
	            if(StringUtils.isNotBlank(param)){//等价于 str != null && str.length > 0 && str.trim().length > 0
	                if(xssRequest.checkXSSAndSql(param)){//进行参数审查
	                    response.setCharacterEncoding("UTF-8");
	                    response.setContentType("application/json;charset=UTF-8");
	                    PrintWriter out = response.getWriter();
	                    out.write(JSONObject.toJSONString(Result.error("401", "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;
	                }
	            }
	        }

	        /**
	         * 检查参数的时候 同时检查请求的方法
	         * 只检查get请求方法和post请求方法的的参数的数据是否合法
	         * 并不是所有参数都要检查，首先必须是一个get或者post，再去校验参数
	         * 因为PUT方法在进行参数审查的时候没办法通过所以直接过滤掉
	         */
	        if (xssRequest.checkParameter()&&(method.equals("POST") || method.equals("GET"))){
	            response.setCharacterEncoding("UTF-8");
	            response.setContentType("application/json;charset=UTF-8");
	            PrintWriter out = response.getWriter();
	            out.write(JSONObject.toJSONString(Result.error("401", "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);
		
	}
	
	// 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;
    }

}

创建拦截器第三步

在webconfig中注册过滤器XssAndSqlFilter

@Configuration
@EnableWebMvc
public class SpringMVCConfig extends WebMvcConfigurerAdapter {
    @Bean
	public FilterRegistrationBean xssFilterRegistrationBean() {
		// 创建一个自定义的 Filter
		FilterRegistrationBean filterRegistrationBean = new FilterRegistrationBean();
		filterRegistrationBean.setFilter(new XssAndSqlFilter());
		filterRegistrationBean.setOrder(1);
		filterRegistrationBean.setEnabled(true);
		filterRegistrationBean.addUrlPatterns("/*");
		// 过滤指定请求地址
		Map<String, String> initParameters = new HashMap<String, String>();
		initParameters.put("excludes", "/auth/login,/auth/code,/auth/phone,/swagger-ui.html/**,/swagger-resources/**,/webjars/**,/v2/api-docs/**,/upload_file/**");
		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。